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SV. e. • 1 , cz)1 inr x 4**********. 99-m-3 cs-tom' b, T&E Investment Inc.Ann Nichols Dick Gilroy 353 Vuemont PI NE La Pianta Limited Partnership Northward Development Renton,WA 98056 PO Box 88028 1560 140th Ave NE Suite 100 Tukwila,WA 98138 Bellevue,Wa 98005-3256 LP La Pianta Craig Krueger AQ o rJ PO Box 88028 Dodds Engineering Tukwila WA 98138 L- 4205-148th Ave NE Suite 200 jv-e Bellevue WA 98007 V / t icsa h ANMARCO CO David L.Halinen 9125 10th Ave. S. Halinen Law Offices,P.S. Seattle,WA 98108 2115 N.30th,Suite 102 Tacoma,W/A 98403 1 gzz3 00 19991213000395 PAGE 001 OF 009 MUM KING3COUNTY10WA5 CITY OF RENTON AG 16. 0LUR- 94"5X WHEN RECORDED RETURN TO: Office of the City Clerk Renton City Hall 1055 South Grady Way Renton,WA 98055 DEVELOPMENT AGREEMENT PARTIES AC edizte,4,44,- 74 This agreement is made and entered into this 1-8th day of Neeember, 1999, by and between the CITY OF RENTON ("City"), a municipal corporation of the State of Washington, and LA PIANTA LIMITED PARTNERSHIP, a Washington limited partnership, the owner of the parcels of property within the area covered by this development agreement ("Owner"). cn RECITALS WHEREAS, the Owner made application to the City of Renton on March 31, 1999 for Comprehensive Plan Land Use Map amendments and Zoning Map amendments of the Owner's property that is legally described as follows (the"Property"): Cy) CT) PARCELS 1, 2, 3, 4, 9 AND 10 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN THE CITY OF RENTON, KING COUNTY, WASHINGTON; EXCEPT THAT PORTION OF SAID PARCEL 1 LYING WEST OF THE WEST LINTE OF SAID SECTION i 6. WHEREAS, the City has assigned City File Nos. LUA 99-054 and 99-M-3 to the Owner's requests; and WHEREAS, the owner seeks to have the following-described portion of the Property (the RO Area", which is approximately 74.05 acres in size) given a Residential Options (RO) Land Use Map designation and R-10 zoning: PARCELS 1, 2, 3, 4, 9 AND 10 CITY OF RENTON,LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, DEVELOPMENT AGREEMENT--Page 1 I I 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN THE CITY OF RENTON, KING COUNTY, WASHINGTON; EXCEPT THAT PORTION OF SAID PARCEL 1 LYING WEST OF THE WEST LINE OF SAID SECTION 16; AND EXCEPT THAT PORTION LYING WITHIN A PARCEL OF LAND DESCRIBED AS FOLLOWS: THAT PORTION OF PARCELS 2, 4, AND 9 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN KING COUNTY WASHINGTON, DESCRIBED AS FOLLOWS: COMMENCING AT THE WEST QUARTER CORNER OF SAID SECTION 16; THENCE, SOUTH 01°04'02" WEST, ALONG THE WEST LINE THEREOF, 601.36 FEET; THENCE, SOUTH 88°55'58" EAST, PERPENDICULAR TO SAID WEST LINE THEREOF, 378.15 FEET, TO THE NORTHWESTERLY LINE OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2571770,RECORDS OF KING COUNTY, WASHINGTON, AND THE TRUE POINT OF BEGINNING; THENCE, NORTH 34°05'53" EAST, ALONG SAID NORTHWESTERLY LINE, 1416.63 FEET TO A POINT ON A CURVE, r,THE CENTER OF WHICH BEARS SOUTH 50°15'19" WEST; THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 197.38 FEET, THROUGH A CENTRAL ANGLE OF 16°09'26", AN ARC DISTANCE OF 55.66 FEET; THENCE, NORTH 55°54'08" WEST, 958.13 FEET TO A POINT OF CURVE; THENCE NORTHWESTERLY ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 399.32 FEET, THROUGH A CENTRAL ANGLE OF rn 27° 17' 11", AN ARC DISTANCE OF 190.17 FEET; THENCE, NORTH 83°11'18"WEST, 18.88 FEET,TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 82°55'25"EAST, THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 2470.00 FEET, THROUGH A CENTRAL ANGLE OF 02°37'08", AN ARC DISTANCE OF 112.90 FEET TO THE EASTERLY MARGIN OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2513101, RECORDS OF KING COUNTY, WASHINGTON; THENCE, SOUTH 26°46'02" EAST, ALONG SAID EASTERLY MARGIN THEREOF, 163.94 FEET; THENCE, CONTINUING ALONG SAIL)EASTERLY MARGIN, SOUTH 06°20'40" EAST, 1566.43 FEET TO THE TRUE POINT OF BEGINNING. WHEREAS, the owner seeks to have the remainder of the Property (the"RPN Area", which DEVELOPMENT AGREEMENT--Page 2 is 20 acres of the site) (the minimum size permitted under Comprehensive Plan Policy LU-57) given a Residential Planned Neighborhood (RPN) Land Use Map designation and corresponding R-14 zoning: THAT PORTION OF PARCELS 2, 4, AND 9 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN THE CITY OF RENTON, KING COUNTY, WASHINGTON, DESCRIBED AS FOLLOWS: COM:I NCING AT THE WEST QUARTER CORNER OF SAID SECTION 16; THENCE, SOUTH 01°04'02" WEST, ALONG THE WEST LINE THEREOF, 601.36 FEET; THENCE, SOUTH 88°55'58" EAST, PERPENDICULAR TO SAID WEST LINE THEREOF, 378.15 FEET, TO THE NORTHWESTERLY LINE OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2571770, RECORDS OF KING COUNTY, WASHINGTON, AND THE TRUE POINT OF BEGINNING; THENCE, NORTH 34°05'53" EAST, ALONG SAID NORTHWESTERLY LINE, 1416.63 FEET TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 50°15'19" WEST; THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 197.38 FEET, THROUGH A CENTRAL ANGLE OF 16`09'26", AN ARC DISTANCE OF 55.66 FEET; THENCE, NORTH 55°54'08" WEST, 958.13 FEET TO A POINT OF CURVE;THENCE NORTHWESTERLY ON SAID CURVE TO THE C7D LEFT, HAVING A RADIUS OF 399.32 FEET, THROUGH A CENTRAL ANGLE o OF 27° 17' 11", AN ARC DISTANCE OF 190.17 FEET; THENCE, NORTH 83°11'18"WEST, 18.88 FEET, TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 82°55'25"EAST, THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 2470.00 FEET, THROUGH A CENTRAL 6, ANGLE OF 02°37'08", AN ARC DISTANCE OF 112.90 FEET TO THE EASTERLY MARGIN OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2513101, RECORDS OF KING COUNTY, WASHINGTON; THENCE, SOUTH 26°46'02" EAST, ALONG SAID EASTERLY MARGIN THEREOF, 163.94 FEET; THENCE, CONTINUING ALONG SAID EASTERLY MARGIN, SOUTH 06°20'40" EAST, 1566.43 FEET TO THE TRUE POINT OF BEGINNING. WHEREAS, the major emphasis of the Owner's proposal is to provide an opportunity for a residential development with a mix of urban residential forms while maintaining a development intensity that it is roughly comparable to conventional, detached single-family development; and DEVELOPMENT AGREEMENT--Page 3 WHEREAS,to ensure that this emphasis will be achieved, the Owner has had three different analyses performed to provide baseline conditions for development restrictions to be embodied in a Development Agreement between the City and the Owner and recorded to run with the land; and WHEREAS, as the first of the three analyses, Dodds Engineers, Inc. has (a) evaluated the number of conventional, detached single-family lots that could reasonably be achieved under the Property's current Residential Single Family Land Use Map designation and R-8 zoning and (b) determined that 413 such lots could reasonably be achieved; WHEREAS, as the second of the analyses, the traffic analysis consulting firm David I. Hamlin & Associates has calculated the anticipated number of average daily trips that would be generated by 413 conventional, detached single-family residential lots as calculated under the 1997 Institute of Transportation Engineers (ITE)Manual and has determined that 3,952 average daily trips would be anticipated for that many lots; WHEREAS, as to the third of the analyses, Dodds Engineers, Inc. has (a) reviewed the detailed stormwater detention calculations for the "Cedar Crest Manufactured Home Park" (a development proposal that was previously-approved for the Property and still vested) to determine the amount of impervious surface that was anticipated for the Property under that development proposal and (b) determined from its review of those calculations that a total of 45.04 acres of impervious surface were anticipated for Cedar Crest; WHEREAS, staff members of the City's Department of Economic Development and Neighborhood Strategic Planning and of the City's Department of PlanningBuilding/Public Works have reviewed the three above-referenced analyses and concur with their conclusions; c WHEREAS, in view of those three analyses, the Owner is willing to have the requested o comprehensive plan designations and zoning be granted subject to a Development Agreement that would embody the following site-specific restrictions (the "Site-Specific Restrictions"): 1) Permitted residential development in the RO Area and RPN Area would be limited so that the number and type of residential units would not be expected to generate more than 3,952 average daily trips as calculated under the 1997 Institute of Transportation Engineers (ITE)Manual; 2) Permitted residential development in the RO Area and RPN Area would be limited so that the total impervious surface coverage due to development would not be allowed to exceed a total of 45.04 acres; 3) The overall number of residential units of any type could not exceed 460 units; 4) The overall number of flats (which would only be constructed in the RPN DEVELOPMENT AGREEMENT--Page 4 Area)could not exceed 78 units and the number of flats in any such building could not exceed 6 units; and 5) The residential density of the portion of the RPN Area lying within Aquifer Protection Zone I shall be limited to 10 dwelling units per acre. WHEREAS, the Planning Commission held a public hearing about the proposed Comprehensive Plan Map Amendments and Zoning Map Amendments and the associated development agreement on July 14, 1999; and WHEREAS, the City Council adopted a Planning and Development Committee report on September 27, 1999; WHEREAS, this development agreement has been presented at a public hearing before the City Council held on the 11th day of October, 1999; and WHEREAS,the City Council has taken into account the public comment presented at that public hearing; and WHEREAS, this development agreement has been reviewed and approved by the City Council of the City of Renton, Washington; and WHEREAS, this development agreement appears to be in the best interests of the citizens of the City of Renton, Washington; a-> NOW, THEREFORE, the parties do agree as follows: SECTION 1. AUTHORITY Pursuant to RCW 36.70B.170(1), the City and persons with ownership or control of real property are authorized to enter into a development agreement setting forth development standards and any other provisions that shall apply to, govern, and vest the development, use, and mitigation Q of the development of the real property for the duration of such development agreement. SECTION 2. SUBJECT PROPERTIES A. Illustrative Map: The Property and the RO Area and RPN Area that comprise it are graphically represented in the drawing attached as Exhibit A. B. King County Property Identification Numbers: The following list indicates the King County Property Identification Numbers applicable at the time of this development agreement: 172305-9171-03, 162305-9007-04, 162305-9009-02, 162305-9010-09, 162305- 9006-05 and 162305-9061-10. DEVELOPMENT AGREEMENT--Page 5 SECTION 3. COMPREHENSIVE PLAN MAP DESIGNATIONS AND ZONING: A. Comprehensive Plan Map Designations: The parties agree that, subject to the Site- Specific Restrictions listed on page 4, above, (1) the RO Area shall have a Residential Options (RO) Land Use Map designation and (2) the RPN Area shall have a Residential Planned Neighborhood (RPN)Land Use Map designation. B. Zoning: The parties further agree that, subject to the Site-Specific Restrictions listed on page 4, above, (1) the RO Area shall have an R-10 zoning classification and (2) the RPN Area shall have an R-14 zoning classification. SECTION 4. EFFECT OF DEVELOPMENT AGREEMENT Unless amended or terminated, this Development Agreement is enforceable during its term by a party to this Development Agreement; provided, however, only the City may enforce the Site- Specific Restrictions. Development of the Property shall not be subject to a new zoning ordinance or an amendment to a zoning ordinance or development standard adopted by the City after the effective date of this Development Agreement, unless (a) otherwise provided in this Development Agreement or(b) agreed to by the owner(s) of any of the portion(s) of the Property to which such new zoning ordinance or an amendment to a zoning ordinance or development standard shall apply. Any development permit or approval issued by the City for the Property after execution of this Development Agreement must be consistent with this Development Agreement. SECTION 5. AUTHORITY RESERVED Cr-.) o Pursuant to RCW 36.70B.170(4) the City reserves its authority to impose new or different regulations to the extent required by a serious threat to public health and safety. SECTION 6. RECORDING rn Pursuant to RCW 36.70B.190, this development agreement shall be recorded with the real property records of King County. During the term of the development agreement, the agreement is binding on the parties and their successors. SECTION 7. TERM This development agreement runs in perpetuity with the Properties, unless amended or rescinded by the City Council in accordance with the procedures of Section 8, below. With respect to any portion(s) of the Property that are not developed, the parties to this development agreement agree to evaluate the agreement periodically, but not less than every ten (10) years. Where appropriate, periodic review of the development agreement shall generally coincide with the City's evaluation of its entire Comprehensive Plan every ten years, pursuant to RMC Title 4 in effect at the time of this agreement, or as thereafter amended. DEVELOPMENT AGREEMENT--Page 6 I 1 VIENDMENT isions of this agreement may only be amended with the mutual consent of the however,that the owner(s)of portion(s) of the Property shall be entitled to amend agreement from time-to-time (with the consent of the City) as it relates to their ppeared before roperty. No additions or alterations of the terms of this agreement shall be valid s authorized to iting and formally approved and executed by the duly authorized agents of the City he Washington s) of the portion(s) of the Property to which such amendment(s) relate. The City ledged the said posed amendments to the development agreement after a public hearing by the urposes therein tg body, and any amendments shall be adopted by ordinance or resolution of the nd that the seal l thereafter recorded. t this 1h day of Pre , 1999. CI RENTON 11 By: Je Tanner, Mayor 11 11 1. Attest: 11.,.,,tLeI/- .Marilyn i 01/ n J. ' en, City Clerk Approved as to Form: who appeared 0( 2 414-itg-t.vas authorized ELOPMENT, Lawrence J. Warren, Ci y Attorney TA LIMITED Df such limited LA PIANTA LIMITED PARTNERSHIP, a Washington limited partnership IP By: METRO LAND DEVELOPMENT, INC., P' a Washington corporation, its General i Partner Ns BY:'9 AYi 9 t M.A. Segale, .. resident Date a gmi Wgmt.F6 vT AGREEMENT--Page 7 EXHIBIT A COMPREHENSIVE PLAN AMENDMENT 99—M-3 RS to RO and RPN 0 0 0 cn cr) 0 v°// RC (no change) Land use designation boundary 0 500 1 ,000 Neighborhoods & Strategic Planning i a 0. Dennison 1.6 0 0 05October1009 U/f- 99-eV/ CITY OF RENTON, WASHINGTON ORDINANCE NO. 4813 AN ORDINANCE OF THE CITY OF RENTON, WASHINGTON CHANGING THE ZONING CLASSIFICATION OF CERTAIN PROPERTIES WITHIN THE CITY OF RENTON FROM RESIDENTIAL MOBILE HOME (RMH) TO RESIDENTIAL-10 DWELLING UNITS PER ACRE (R-10) AND RESIDENTIAL-14 DWELLING UNITS PER AC R-14) (LA PIANTA LIMITED PARTNERSHIP; CPA 99-M-3; FILE . LUA 99-054: WHEREAS, under Section 4.2.020 of Chapter 2, Land Use Districts, of Title 4 (Development Regulations), of Ordinance No. 4260 known as the "Code of General Ordinances of the City of Renton," as amended, and the maps and reports adopted in conjunction therewith, the property hereinbelow described has heretofore been zoned as Residential Mobile Home (RMH); and WHEREAS, the City of Renton initiated a proceeding for change of zone classification of said property. This matter was duly referred to the Planning Commission for investigation, study, and public hearing, and a public hearing having been held thereon on or about July 14, 1999, and said matter having been duly considered by the Planning Commission, and said zoning request being in conformity with the City's Comprehensive Plan, as amended by Ordinance No. 4796 and the City Council having duly considered all matters relevant thereto, and all parties having been heard appearing in support thereof or in opposition thereto; NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF RENTON, WASHINGTON, DO ORDAIN AS FOLLOWS: SECTION I. The following described property in the City of Renton is hereby rezoned to Residential-10 DU/AC (R-10) and Residential-14 DU/AC (R-14), as hereinbelow specified. The Neighborhood and Strategic Planning Division is hereby authorized and directed to change the maps of the Zoning Ordinance, as amended, to evidence said rezoning, to-wit: 1 ORDINANCE NO. 4813 if See Exhibit "A" attached hereto and made a part hereof as if fully set forth herein. The rezone area consists of 94.05 acres located on the south side of N.E. 3rd/4th Streets and east of Edmonds Avenue N.E.) SECTION II. This Ordinance shall be effective upon its passage, approval, and five days after its publication. PASSED BY THE CITY COUNCIL this 8th day of November 1999. Marilyn J. 'et: , City Clerk APPROVED BY THE MAYOR this 8th day of November 1999. I Jess:. . er, Mayor Approved f Lawrence ftvarrpen,ey Date of Publication: 11/12/99 (Summary) ORD.8 01:10/06/99:as. 2 111 ORDINANCE NO. 4813 Legal Description of the R-10 Parcel PARCELS 1, 2, 3, 4, 9 AND 10 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B,UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN THE CITY OF RENTON, KING COUNTY, WASHINGTON;EXCEPT THAT PORTION OF SAID PARCEL 1 LYING WEST OF THE WEST LINE OF SAID SECTION 16; AND EXCEPT THAT PORTION LYING WITHIN A PARCEL OF LAND DESCRIBED AS FOLLOWS: THAT PORTION OF PARCELS 2, 4, AND 9 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN KING COUNTY WASHINGTON,DESCRIBED AS FOLLOWS: COMMENCING AT THE WEST QUARTER CORNER OF SAID SECTION 16; THENCE, SOUTH 01°04'02" WEST, ALONG THE WEST LINE THEREOF, 601.36 FEET; THENCE, SOUTH 88°55'58" EAST, PERPENDICULAR TO SAID WEST LINE THEREOF, 378.15 FEET, TO THE NORTHWESTERLY LINE OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2571770, RECORDS OF KING COUNTY, WASHINGTON, AND THE TRUE POINT OF BEGINNING; THENCE, NORTH 34°05'53" EAST, ALONG SAID NORTHWESTERLY LINE, 1416.63 FEET TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 50°15'19" WEST; THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 197.38 FEET, THROUGH A CENTRAL ANGLE OF 16°09'26", AN ARC DISTANCE OF 55.66 FEET; THENCE, NORTH 55°54'08" WEST, 958.13 FEET TO A POINT OF CURVE; THENCE NORTHWESTERLY ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 399.32 FEET, THROUGH A CENTRAL ANGLE OF 27° 17' 11", AN ARC DISTANCE OF 190.17 FEET; THENCE, NORTH 83°11'18" WEST, 18.88 FEET, TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 82°55'25" EAST, THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 2470.00 FEET, THROUGH A CENTRAL ANGLE OF 02°37'08", AN ARC DISTANCE OF 112.90 FEET TO THE EASTERLY MARGIN OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2513101, RECORDS OF KING COUNTY, WASHINGTON; THENCE, SOUTH 26°46'02" EAST, ALONG SAID EASTERLY MARGIN THEREOF, 163.94 FEET; THENCE, CONTINUING ALONG SAID EASTERLY MARGIN, SOUTH 06°20'40" EAST, 1566.43 FEET TO THE TRUE POINT OF BEGINNING. EXHIBIT "A"--Page 2 ORDINANCE NO. 4813 Legal Description of the R-14 Parcel THAT PORTION OF PARCELS 2, 4, AND 9 CITY OF RENTON, LOT LINE REVISION, FILE NO. LUA-95-200-LLA, RECORDED IN BOOK 108 OF SURVEYS, PAGE 276, 276 A AND 276 B, UNDER RECORDING NUMBER 9604239004, RECORDS OF KING COUNTY, WASHINGTON; BEING A PORTION OF SECTION 16, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M. IN THE CITY OF RENTON, KING COUNTY, WASHINGTON, DESCRIBED AS FOLLOWS: COMMENCING AT THE WEST QUARTER CORNER OF SAID SECTION 16; THENCE, SOUTH 01°04'02" WEST, ALONG THE WEST LINE THEREOF, 601.36 FEET; THENCE, SOUTH 88°55'58"EAST,PERPENDICULAR TO SAID WEST LINE THEREOF, 378.15 FEET, TO THE NORTHWESTERLY LINE OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2571770, RECORDS OF KING COUNTY, WASHINGTON, AND THE TRUE POINT OF BEGINNING; THENCE, NORTH 34°05'53" EAST, ALONG SAID NORTHWESTERLY LINE, 1416.63 FEET TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 50°15'19" WEST; THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 197.38 FEET, THROUGH A CENTRAL ANGLE OF 16°09'26", AN ARC DISTANCE OF 55.66 FEET; THENCE, NORTH 55°54'08" WEST, 958.13 FEET TO A POINT OF CURVE; THENCE NORTHWESTERLY ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 399.32 FEET, THROUGH A CENTRAL ANGLE OF 27° 17' 11", AN ARC DISTANCE OF 190.17 FEET; THENCE, NORTH 83°11'18" WEST, 18.88 FEET, TO A POINT ON A CURVE, THE CENTER OF WHICH BEARS SOUTH 82°55'25" EAST, THENCE ON SAID CURVE TO THE LEFT, HAVING A RADIUS OF 2470.00 FEET, THROUGH A CENTRAL ANGLE OF 02°37'08", AN ARC DISTANCE OF 112.90 FEET TO THE EASTERLY MARGIN OF PUGET SOUND POWER AND LIGHT CO. EASEMENT AS DESCRIBED IN AN INSTRUMENT RECORDED UNDER RECORDING NUMBER 2513101, RECORDS OF KING COUNTY, WASHINGTON; THENCE, SOUTH 26°46'02" EAST, ALONG SAID EASTERLY MARGIN THEREOF, 163.94 FEET; THENCE, CONTINUING ALONG SAID EASTERLY MARGIN, SOUTH 06°20'40" EAST, 1566.43 FEET TO THE TRUE POINT OF BEGINNING. EXHIBIT"A"--Page 3 ORDINANCE NO. 4813 PIANTA REZON. H to R-10 and R-14' w a S I 0 0 10 R — 1 4 R - 1O S64o0i G RC (no change) 1Sp5t1IStfIl T Zone boundaries 0 500 1 ,000 G1,i, Neighborhoods & Strategic Planning ED/N/SP O. Dennison TO 5 October 1999 1 :6,0 0 0 AFFIDAVIT OF PUBLICATION Charlotte Ann Kassens first duly sworn on oath states that he/she is the Legal Clerk of the SOUTH COUNTY JOURNAL RENTON CITY COUNCIL 600 S. Washington Avenue, Kent, Washington 98032 Following is summary of ordinance adopted by the Renton City Council on November 8,1999: a daily newspaper published seven (7)times a week. Said newspaper is a legal ORDINANCE NO.4813 newspaper of general publication and is now and has been for more than six months An ordinance of the City of Renton, Washington, changing the.zoning classifi- prior to the date of publication, referred to, printed and published in the English language cation of certain properties within the City continually as a daily newspaper in Kent, King County, Washington. The South County of Renton from Residential Mobile Home Journal has been approved as a legal newspaper order of the Superior Court of the Acre( -o Residential 1d Dwelling- 1 Units Per PP 9by P Acre (R-10) and Residential-14 Dwelling State of Washington for King County. Units Per Acre (R-14) (La Pianta Limited The notice in the exact form attached, was published in the South County Partnership;CPA 99-M-3;File No.LUA-99- 054). Journal (and not in supplemental form)which was regularly distributed to the subscribers Effective: 11/17/99 during the below stated period. The annexed notice, a Complete text of this ordinance can be read at Renton City Hall, City Clerk Division 7th Floor, 1055 So. Grady Way, Ordinance#4813 and at the Renton Public Library, 100 Mill Avenue South. Upon request to the City Clerk's office (425-430-6510) copies will as published on: 11/12/99 also be mailed for a fee. Marilyn J.Petersen The full amount of the fee charged for said foregoing publication is the sum of$37.38,City Cl shed in Manager r9 9 9 Published in the South County Journal charged to Acct. No. 8050640.November 12,1999.6845 Legal Number 6845 ega Clerk, ou Couy Journal Subscribed and sworn before me on this A;--"'flay of 6y- , 19( FoQ ajct cvRr '. `y Notary Public of the State of Washington a@— • - residing in Renton King County, Washington i,J9TFC ? 6 :1 ` G```w l e• w a1 it9:au 1c` v November 8, 1999 Renton City Council Minutes Page 400 IN THE COMMITTEE REPORT. CARRIED. Finance Committee Finance Committee Chair Edwards presented a report recommending approval Finance: Vouchers of Claim Vouchers 175998 - 176454 and two wire transfers in the total amount of$2,823,597.42; and approval of Payroll Vouchers 22552 -22784 and 522 direct deposits in the total amount of$954,929.27. MOVED BY EDWARDS, SECONDED BY CORMAN, COUNCIL CONCUR IN THE COMMITTEE REPORT. CARRIED. ORDINANCES AND The following resolutions were presented for reading and adoption: RESOLUTIONS Resolution#3420 A resolution was read authorizing the temporary closure of Main Ave. S. Streets: Main Ave S between S. 2nd and S. 4th Streets, and of Mill Ave:'S. at the railway crossing at Temporary Closures Houser Way South. MOVED BY SCHLITZER, SECONDED BY NELSON, COUNCIL ADOPT THE RESOLUTION AS READ. CARRIED.Streets: Mill Ave S Temporary Closures Resolution#3421 A resolution was read authorizing the Mayor and City Clerk to enter into an Public Works: Inflow& interlocal cooprative agreement with King County entitled"Utilities Infiltration Program Study,Cooperation Agreement By and Between the City of Renton and King County King County Agreement for an Inflow/Infiltration Program Study." MOVED BY CLAWSON, SECONDED BY SCHLITZER, COUNCIL ADOPT THE RESOLUTION AS READ. CARRIED. The following ordinance was presented for second and final reading: Ordinance#4813 An ordinance was read changing the zoning classification of 94.05 acres Development Services: La located on the south side of NE 3rd/NE 4th Streets, east of Edmonds Ave.NE, Pianta Project,NE 3rd/NE 4th from Residential Mobile Home (RMH)to Residential-10 Dwelling Units Per and Edmonds Ave NE Acre (R-10) and Residential-14 Dwelling Units Per Acre R-14 (La Pianta Limited Partnership, R-99-054). MOVED BY NELSON, SECONDED BY SCHLITZER,COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. ADJOURNMENT MOVED BY PARKER, SECONDED BY NELSON, COUNCIL ADJOURN. CARRIED. Time: 8:08 p.m. MARILYN J. PETERSEN, CMC, City Clerk Recorder: Brenda Fritsvold November 8, 1999 October 25, 1999 Renton City Council Minutes Page 378 CC (R-98-042) R-98-042). MOVED BY CLAWSON, SECONDED BY SCHLITZER, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4800 An ordinance was read changing the zoning classification of approximately 17.1 Rezone: Southport Project acres located between Gene Coulon Park on the east, Boeing Manufacturing Shuffleton Site), from IH to Operations on the west, and Lake Washington on the north from Heavy Industrial COR (R-99-027) IH)to Center Office Residential (COR) for the Southport Project(Seco Development, R-99-027). MOVED BY CORMAN, SECONDED BY SCHLITZER, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4801 An ordinance was read changing the zoning classification of approximately 4.8 Rezone: Lakeridge acres located at 3521 Cedar Ave. S. from Residential -Eight Dwelling Units Per Development, 3521 Cedar Ave Acre (R-8)to Residential - 10 Dwelling Units Per Acre(R-10) for Lakeridge S, from R-8 to R-10 (R-99-Development(R-99-053). MOVED BY CLAWSON, SECONDED BY 053) NELSON, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Rezone: La Pianta Councilmember Keolker-Wheeler explained that the ordinance for the La Pianta Development,NE 3rd/4th Sts, rezone (approximately 94.05 acres located on the south side of NE 3rd and 4th from RHM to R-10 and R-14 Streets and east of Edmonds Ave. NE) from Residential Mobile Home (RMH)to R-99-054) Residential- 10 Dwelling Units Per Acre (R-10) and Residential- 14 Dwelling Units Per Acre(R-14) is also being held for further action, and will not be presented for second and final reading this evening. Ordinance#4802 An ordinance was read amending Title 4 (Development Regulations) of City Planning: Center Office Code by adding a Center Office Residential-3 Zone, amending Center Office Residential Zone Amendments Residential use allowances and development standards, amending site plan Southport Project) review procedures, deleting master site plan approval procedures, and amending modification procedures. MOVED BY KEOLKER-WHEELER, SECONDED BY CORMAN, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4803 An ordinance was read amending subsections 4-2-060.F, G and K, 4-2-070.I, J, Planning: Commercial Arterial K, L, M,N, 0, P, Q and R, 4-2-080.A, and 4-2-120.A and C of Chapter 2, Land and Convenience Commercial Use Districts, of Title 4 (Development Regulations) of City Code by adding Zone Amendments (Taco Time allowances for office uses and minor repair in the Commercial Arterial (CA) Headquarters Expansion) Zone, adding allowances for existing, legal administrative headquarters offices in the Convenience Commercial (CC)Zone, and adding allowances for accessory storage in the commercial and industrial zones. MOVED BY CLAWSON, SECONDED BY NELSON, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4804 An ordinance was read designating a Planned Action for the Southport site, Planning: Southport Project approximately 17 acres located adjacent to Lake Washington and between Gene Planned Action Ordinance Coulon Memorial Beach Park on the east and Boeing Manufacturing Operations on the west. MOVED BY SCHLITZER, SECONDED BY CORMAN, COUNCIL ADOPT THE ORDINANCE AS READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4805 An ordinance was read increasing golf lesson fees. MOVED BY EDWARDS, Budget: 2000, Golf Lesson Fee SECONDED BY NELSON, COUNCIL ADOPT THE ORDINANCE AS Increases READ. ROLL CALL: ALL AYES. CARRIED. Ordinance#4806 An ordinance was read increasing animal license fees. MOVED BY October 11, 1999 Renton City Council Minutes Page 351 Ms. Grueter said the project has already received certain necessary approvals from the City Council for a Comprehensive Plan map amendment from Employment Area—Industrial to Center Office Residential (COR)along with a rezone from Heavy Industrial to COR, in addition to COR policy amendments and Renton Municipal Code amendments. The Planned Action Ordinance includes a mitigation document which would be applied to all future development applications on the site. Ms. Grueter explained that future applications would also be subject to thresholds and review criteria. Specifically, additional environmental review would be required if there is a 10%or greater increase in building height or if changes are proposed to the already-determined minimum average building setbacks, amount of open space provided, or number of transportation trip levels. Other issues considered will be each application's impact on air quality, fisheries, grading, peak water flow and outfalls, and public services and utilities. Ms. Grueter emphasized that all applications will be required to conform with the City's notification process. The built-in monitoring period extends to December 1, 2004, which reflects the horizon year for completion of the proposed development. Staff recommends approval of the proposed Planned Action Ordinance. Referring to citizen concerns about traffic congestion in this area, Councilman Clawson asked how vehicle movement to and from this project will be routed. Saying that the traffic implications of this project were given a great deal of consideration, Ms. Grueter explained that mitigation improvements will be made to Lake Washington Boulevard between the Southport entrance and the Park Avenue intersection to facilitiate traffic movement to the south rather than to the north. Although staff is comfortable with the assumptions made by the City's Transportation Systems Division regarding vehicle distribution in this area, traffic will be continued to be monitored for two years after full build-out of the development to assess its final effects. Audience comment was invited. There being none, it was MOVED BY PARKER, SECONDED BY CORMAN, COUNCIL CLOSE THE PUBLIC HEARING. CARRIED. ePlanning: La Pianta This being the date set and proper notices having been posted and published in Development Agreement(NE accordance with local and State laws, Mayor Tanner opened the public hearing 3rd and 4th between Edmonds to consider the proposed La Pianta Development Agreement: 94.2 acres located and Monroe) on the south side of NE 3rd and 4th Streets between Edmonds Ave. NE(if extended) and Monroe Ave.NE; proposal includes changing 74.2 acres to Residential Options (R-10)and 20 acres to Residential Planned Neighborhood designation(R-14). Rebecca Lind, Senior Planner, said the property would have access from the extension of Edmonds Ave.NE as it leads into the La Calina plat. A vested project on the property would allow a 402-unit senior manufactured home park; the new proposal would replace the already-vested project and include the proposed development agreement to regulate future development on the site. The agreement, which would be binding for any future owners, would provide for a ten-year review period that would correspond with the City's ten-year review of the Comprehensive Plan. Ms. Lind described the specific terms of the agreement, would which allow 460 i October 11, 1999 Renton City Council Minutes Page 352 units to be built(78 flats with no more than six units per building). Impervious surface would be limited to 45 acres. The RPN-zoned portion of the property which lies within the Aquifer Protection Zone would be restricted to ten units per acre. Ms. Lind said without the development agreement, the property could be developed to a density of 535 to 694 units. Impervious surface could increae substantially,to a maximum of 75%of the property. Staff and the Planning& Development Committee recommend approval of the agreement. Responding to Councilmember Keolker-Wheeler, Ms. Lind explained that the proposed development agreement has been revised since last week to correct the legal description, since the applicant has asked that a certain part of the property be forwarded to next year's Comprehensive Plan review cycle. Additionally, paragraph(5) on page four was amended to clarify its reference to a portion of the property which lies within the Aquifer Protection Zone 1, rather than outside of it. Audience comment was invited. David L. Halinen, 10500 NE 8th St., Suite 1900, Bellevue, 98004, representing the proponent, explained that the applicant has asked that a small (roughly 0.9 acre) portion of the property located in the northwest corner perpendicular to NE 3rd Street be tabled until next year's Comprehensive Plan review cycle. The proponent intends to seek Convenience Commercial zoning for this piece at that time. Councilman Schiltzer emphasized that the zoning for the Resource Conservation area located on the southern portion of the parcel, which is characterized by steep slopes, will not change. Correspondence was read from Everett Wilcock, 11830 - 164th Ave. SE, 98059, urging the City to impose greater density requirements on this property, which he felt constituted one of the last remaining large-sized parcels suitable for development as an urban village. Mr. Wilcock said the region will be able to appropriately accommodate its growth projects only if it does not squander its close-in land by allowing it to be developed at rural densities. MOVED BY SCHLITZER, SECONDED BY EDWARDS, COUNCIL REFER THIS LETTER TO THE PLANNING&DEVELOPMENT COMMITTEE. CARRIED. Responding to Council President Parker, Ms. Lind said the issue of traffic for this project was given significant consideration. Staff determined that the site can easily accommodate 413 single family units with a similar road pattern and layout that was used for the vested mobile home project. The development agreement will cap the traffic generation at this same level, so there is no net increase over the vested project. Mr. Parker wanted to know the average daily number of vehicle trips which NE 4th St. (Cemetery Road) currently experiences. Ms. Lind agreed to provide him this information. There being no further audience comment, it was MOVED BY PARKER, SECONDED BY NELSON, COUNCIL CLOSE THE PUBLIC HEARING. CARRIED. ADMINISTRATIVE Chief Administrative Officer Jay Covington reviewed a written administrative October 11, 1999 Renton City Council Minutes Page 353 REPORT report summarizing the City's recent progress towards goals and work programs adopted as part of its business plan for 1999 and beyond. Items noted included: The Water Utility is poised to distribute the City's first Water Quality Report to water customers this week. The report explains where Renton's water comes from,what it contains,how it meets or exceeds state and federal drinking water quality standards,and what the City is doing to protect its water supply. Renton Municipal Court has introduced a one-time only offer which allows anyone with a parking ticket to save money by paying the original fines plus a$10 late fee,thereby saving the ticket from being sent to a collection agency. This special offer ends Friday, October 29. A Candidate's Forum will be held on Thursday, October 14th at McKnight Middle School. Candidates for Mayor, City Council, School Board and the Port of Seattle will attend. AUDIENCE COMMENT Ralph Evans, 3306 NE 11th Pl., Renton, 98056, questioned if the City has plans Citizen Comment: Evans— to extend Edmonds Ave.NE north to Maple Valley Highway. He felt that the La Traffic Concerns(Bronson Pianta development should have more than one access,particularly as the route Way/Sunset/Maple Valley from the Highlands to downtown Renton,via NE 4th and NE 3rd Streets, is Highway Area) already inadequate for area residents when congestion builds up on Sunset Boulevard and Bronson Way. Ms. Lind explained that the secondary access for this project is via Blaine Ave.; however, staff strongly suggests this steep road be used for emergencies only due to the difficulty of turning movements. Councilman Corman confirmed that this issue is one of many being discussed as part of the I-405 corridor study. Specifically, Renton is looking at whether it would be feasible to connect Cemetery Road(NE 3rd/NE 4th Street)to Maple Valley Highway east of this development. CONSENT AGENDA Items on the consent agenda are adopted by one motion which follows the listing. Finance: 2000 Property Tax Finance&Information Services Department recommended approval of an Rates ordinance establishing the 2000 property tax rates for the City of Renton. Council concur. (See page 355 for legislation.) CAG: 99-038, EW-3 Well Water Utility Division submitted CAG-99-038, EW-3 Well Drilling project;and Drilling Project,Holt Drilling recommended approval of the project, authorization for final pay estimate in the amount of$1,077.44, commencement of 60-day lien period, and release of retained amount of$2,177.37 to Holt Drilling, Inc.,contractor, if all required releases are obtained. Council concur. Councilman Edwards asked whether the proposed ordinance relating to next year's property tax rates should be referred to the Finance Committee. Mayor Tanner replied that because of questions associated with how I-695, if approved, would affect this ordinance, Council is being asked to adopt the legislation before November. The mayor emphasized that Renton is not raising the basic property tax rate, although it does expect to have more property tax revenues next year due to new construction and expected increases in assessed valuation. Finance&Information Services Administrator Victoria Runkle added that State law requires jurisdictions to reserve their right to increase property tax revenues by the allowed 6%figure one year before they adopt such an increase. This CITY OF RENT.ON CURRENT;PLANNING DIVISION AFFIDAVIT OF SERVIiCE;BY MAILING; On the Loth day of V.- 1999, I deposited in the mails of the United. States, a sealed envelope containing e v c. d e'tP Ir van t vtot ms documents. This information was sent to: Name Representing Department of Ecology Don Hurter WSDOT KC Wastewater Treatment Division Larry Fisher Washington Department of Fisheries David F. Dietzman Department of Natural Resources Shirley Lukhang Seattle Public Utilities Duwamish Indian Tribe Rod Malcom Muckleshoot Indian Tribe Joe Jainga Puget Sound Energy Signature of Sender) Scon.cllra. k . SG STATE OF WASHINGTON SS COUNTY OF KING I certify that I know or have satisfactory evidence that. 11 tio,, !•e. Cc% signed this instrument and acknowledged it to be his/her/their free and voluntary act for uses and purposes mentioned in the instrument. Dated: r-- Gz i9_/%9( LY NICHEFF Not?ublic' and f rp State ofington NOTARY PUBLIC Notary (PrintjefARILYN i auCHFfF STATE OF WASHINGTON My appointm Oat APPOINTEAENT FXPIRFS•6-29.034 COMMISSION EXPIRES JUNE j`), 2003 Project Name: Ptah--Ca % evsvu.. ¶ CeWI Ptah ATh.eV Iv eht Project Number: LUA• 411 • 0S4 CPA NOTARY.DOC t- •, CITY ‘._)F RENTON t Planning/Building/Public Works Department Je sse Tanner,Mayor Gregg Zimmerman P.E.,Administrator June 5, 1999 Wash ngton State Department of Ecology Envirc nmental Review Section PO Box 47703 Olymi iia, WA 98504-7703 Subje;t: Environmental Determinations Trans nitted herewith is a copy of the Environmental Determination for the following project reviewed by the Envirc nmental Review Committee (ERC) on June 22, 1999: DETERMINATION OF NON-SIGNIFICANCE-MITIGATED LA PIANTA REZONE AND COMPREHENSIVE PLAN AMENDMENT LUA-99-054,CPA,ECF,R Amend the Land Use Map to change 74.2acres of this property from Residential Single Family with RMH zoning to Residential Options(RO)with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN)with R-14 zoning, and .9 acres to Convenience Commercial with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. Location: South of NE 3`d, East of Edmonds Avenue. Appe rIs of the environmental determination must be filed in writing on or before 5:00 PM July 12, 1999. Appeals must oe filed in writing together with the required $75.00 application fee with: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code Sectic n 4-8-11 B. Additional information regarding the appeal process may be obtained from the Renton City Clerk's Office, (425)-430-6510. If you have questions, please call me at (425) 430-6588. For the Environmental Review Committee, Reber:ca Lind Proje(.t Manager cc: King County Wastewater Treatment Division Larry Fisher, Department of Fisheries David F. Dietzman, Department of Natural Resources Don Hurter, Department of Transportation Shirley Lukhang, Seattle Public Utilities Duwamish Tribal Office Rod Malcom, Fisheries, Muckleshoot Indian Tribe (Ordinance) Joe Jainga, Puget Sound Energy agncyltx 1055 South Grady Way- Renton, Washington 98055 C)Thic nannrrnntainc snw ron irri n,aa.iai n i and nnn n,ar CITY F RENTON IAPlanning/Building/Public Works Department Jesse Tanner,Mayor Gregg Zimmerman P.E.,Administrator June 25, 1999 Ms. nn Nichols La Pianta Limited Partnership PO Box 88028 Tukw la,WA 98138 SUB,ECT: La Pianta Rezone and Comprehensive Plan Amendment Project No. LUA-99-054,CPA,ECF,R Dear Ms. Nichols: This 'letter is written on behalf of the Environmental Review Committee (ERC) and is to advise you that they have completed their review of the subject project. The ERC, on June 22, 1999, issued a threshold Determination of Non Signi`icance-Mitigated with Mitigation Measures. See the enclosed Mitigation Measures document. AppE als of the environmental determination must be filed in writing on or before 5:00 PM July 12, 1999. Appea1. must be filed in writing together with the required $75.00 application fee with: Hearing Examiner, City of Renton, 105'. Soutl Grady Way, Renton, WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code Sectio+ 4-8-1 1 B. Additional information regarding the appeal process may be obtained from the Renton City Clerk's Office, (425 430-E 510. The preceding information will assist you in planning for implementation of your project and enable you to exercise yot appe 11 rights more fully, if you choose to do so. If you have any questions or desire clarification of the above, please cr me a (425) 430-6588. For the Environmental Review Committee, 01 Rebecca Lind Project Manager cc: Parties of Record: T&E Investment, Mr. Dick Gilroy; Mr. Craig Krueger:Anmarco Co., Mr. David Halinen, Ms. Dolores Patterson Enclosure dnsmtl• 1055 South Grady Way - Renton, Washington 98055 CITY OF RENTON DETERMINATION OF NON-SIGNIFICANCE-MITIGATED MITIGATION MEASURES APPLICATION NUMBER: LUA-99-054,CPA,ECF,R APPLICANT: La Pianta Limited Partnership, Ms. Ann Nichols PROJECT NAME: La Pianta Rezone and Comprehensive Plan Amendment DESCRIPTION OF PROPOSAL: Amend the Land Use Map to change 74.2acres of this property from Residential Single Family with RMH zoning to Residential Options(RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN) with R-14 zoning, and .9 acres to Convenience Commercial with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. LOCATION OF PROPOSAL: South of NE 3rd , East of Edmonds Ave. (extended) MITIGATION MEASURES: 1. A Development agreement be approved by the City and recorded as a restrictive covenant running with the title of the property. The Development Agreement shall stipulate as follows: Development to be restricted to a maximum of 460 units. The overall number of flats to be limited to 78 units and the number of flats in any building to be limited to 6. The total impervious surface coverage to be 45 acres as shown in the May 26, 1999 memo from Dodds Engineers. Total traffic generation from all land uses to be not greater than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers ITE Manual as shown in the memo from David I Hamlin and Associates. 2. The portion of the property proposed for Residential Planned Neighborhood Designation which is located in Zone 1 of the Aquifer Protection Area shall be limited to 10 dwelling units per net acre. i NOTICE ENVIRONMENTAL DETERMINATION POSTED TO NOTIFY INTERESTED PERSONS OF AN ENVIRONMENTAL ACTION PROJECT NAME: LA PIANTA REZONE AND COMPREHENSIVE PLAN AMENDMENT PROJECT NUMBER: LUAd9-054,CPA,ECF,R Amend the Land Use Map to change 74.2wes of this properly from Re:Mantal Single Family with RMH zoning to Residential Options(RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN)with R-14 zoning,and.9 mares to Convenience Commercial with CC zoning. The proposal to change land use polities to allow senior stacked Sate within the RPN designation is withdrawn.Location:South of NE J°,East of Edmonds Avenue. THE CITY OF RENTON ENVIRONMENTAL REVIEW COMMITTEE (ERC) HAS DETERMINED THAT THE PROPOSED ACTION DOES NOT HAVE A SIGNIFICANT ADVERSE IMPACT ON THE ENVIRONMENT. Appeals of the environmental determination must be filed in writing on or before 5:00 PM July 12,1999. Appeals must be flied In writing together with the required$75.00 application tee with: Hearing Examiner,City of Renton,1055 South Grady Way,Renton,WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code Section 4-8-11B. Additional Information regarding the appeal process may be obtained from the Renton City Clerk's Office,(425)-4304510. rit1707i' 83171 i iy_.. .,r-- i. , i44,064, 11141m,, 1,.h. _ I FOR FURTHER INFORMATION,PLEASE CONTACT THE CITY OF RENTON,DEVELOPMENT SERVICES DMSION AT(425)430-7200. DO NOT REMOVE THIS NOTICE WITHOUT PROPER AUTHORIZATION Please Include the project NUMBER when calling for proper file identification. CERTIFICATION I, Owe NI J. D ir/L of , hereby certify that copies of the above document were posted by me in 3 conspicuous places on or nearby the described property on j t,„ic 2-t, i 5 S i Signed: ATTEST: Subcribed and sworn before me, a Nortary Pu ' , m and r the State of Washington residing in ,0,2 on the y-/h day of L. /1 . 77/0".., e,...-ie424 /*<_________ MARILYN K.AI.,.'y''-IEFF COMMISSION EXPIRES 6/29/99 CITY OF RENTON DETERMINATION OF NON-SIGNIFICANCE MITIGATED) APPLI(:ATION NO(S): LUA-99-054,CPA,ECF,R APPLICANT: La Pianta Limited Partnership, Ms. Ann Nichols PROJECT NAME: La Pianta Rezone and Comprehensive Plan Amendment DESCRIPTION OF PROPOSAL: Amend the Land Use Map to change 74.2 acres of this property from Residential Single Family with RMH zoning to Residential Options (RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood (RPN) with R-14 zoning, and .9 acres to Convenience Commercial with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. LOCA1 ION OF PROPOSAL: South of NE 3`d, East of Edmonds Ave (extended) LEAD AGENCY: City of Renton Department of Planning/Building/Public Works Development Planning Section The Cii y of Renton Environmental Review Committee has determined that it does not have a probable significant adverse impact on the environment. An Environmental Impact Statement (EIS) is not required under RCW 43.21C.030(2)(c). Condit'ms were imposed as mitigation measures by the Environmental Review Committee under their authority of Sectior 4-6-6 Renton Municipal Code. These conditions are necessary to mitigate environmental impacts identified during he environmental review process. Appea s of the environmental determination must be filed in writing on or before 5:00 PM July 12, 1999. Appeals must t e filed in writing together with the required $75.00 application fee with: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code section 4-8-11B. Additional information regarding the appeal process may be obtained from the Renton City Clerk's Office, (425)430-6510. PUBLI' ATION DATE: June 28, 1999 DATE OF DECISION: June 22, 1999 SIGNATURES: czA6,4______ _ Gregg .Ziinimerman,Administrator DE L Department of Planning/Building/Public s 1 7), jlIL-a--- .,••,..-...--(...- K -:)- (c'( 1( Jim Shy p ierd,-A ministra r DAME jCommunity Services Le a er,Fire2.,..,DATE Renton Fire Department Documei tl CITY OF RENTON DETERMINATION OF NON-SIGNIFICANCE-MITIGATED MITIGATION MEASURES APPLICATION NUMBER: LUA-99-054,CPA,ECF,R APPLICANT: La Pianta Limited Partnership, Ms. Ann Nichols PROJECT NAME: La Pianta Rezone and Comprehensive Plan Amendment DESCRIPTION OF PROPOSAL: Amend the Land Use Map to change 74.2acres of this property from Residential Single Family with RMH zoning to Residential Options(RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN) with R-14 zoning, and .9 acres to Convenience Commercial with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. LOCATION OF PROPOSAL: South of NE 3rd , East of Edmonds Ave. (extended) MITIGATION MEASURES: 1. A Development agreement be approved by the City and recorded as a restrictive covenant running with the title of the property.The Development Agreement shall stipulate as follows: Development to be restricted to a maximum of 460 units. The overall number of flats to be limited to 78 units and the number of flats in any building to be limited to 6. The total impervious surface coverage to be 45 acres as shown in the May 26, 1999 memo from Dodds Engineers. Total traffic generation from all land uses to be not greater than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers ITE Manual as shown in the memo from David I Hamlin and Associates. 2. The portion of the property proposed for Residential Planned Neighborhood Designation which is located in Zone 1 of the Aquifer Protection Area shall be limited to 10 dwelling units per net acre. AFFIDAVIT OF PUBLICATION OCharlotteAnnKassensfirstdulyswornonoathstatesthathe/she is the Legal Clerk of the NOTICE DETT RERMMINAATIONTION AL ENVIRONMENTAL REVIEW SOUTH COUNTY JOURNAL COMMITTEE RENTON,WASHINGTON Th600S. Washington Avenue, Kent, Washington Environmental Review Committee W 98032 ER(EEC) has issued•a Determination of Non- Significance - Mitigated for the following a dailynewspaper seven (7) times a week. Said newspaper is a le al Municipaluc underC the authority of the Renton published9 Code. newspaper of general publication and is now and has been for more than six months LA PIANTA REZONE AND COMP PLAN prior to the date of publication, referred to, printed and published in the English language AMENDMENT L U A-99-054,C PA,E C F,R continually as a daily newspaper in Kent, King County, Washington. The South County Amend the Land Use Map to change 74.2 Journal has been approved as a legal newspaper by order of the Superior Court of the acres of this property from Residential State of Washington for King County. Single Family with RMH zoning to Residential Options (RO) with R-10 zon- The notice in the exact form attached, was published in the South County ing, and 20 acres to Residential Planned Journal (and not in supplemental form)which was regularly distributed to the subscribers Neighborhood (RPN) with r-14 zoning, and .9 acres to Convenience Commercial during the below stated period. The annexed notice, a CC) with CC zoning. The proposal to change land use policies to allow senior LaPianta Rezone stacked flats within the RPN designation is withdrawn. Location: South of NE 3rd, East of Edmonds Ave. as published on: 6/28/99 Appeals of the environmental determina- tion must be filed in writing on or before 5:00 PM July 12, 1999. Appeals must be The full amount of the fee charged for said foregoing publication is the sum of$51.75, filed in writing together with the required. charged to Acct. No. 8051067 75.00 application fee with: Hearing Examiner, City of Renton, 1055 South Grady Way,Renton,WA 98055.Appeals to Legal Number 6288 the Examiner are governed by City of Renton Municipal Code Section 4-8-11B. Additional information regarding the appeal egal le , ou y Journal process may be obtained from the Renton City Clerk's Office,(425)-430-6510. Publication Date: June 28, 1999 Published in the South County Journal Subscribed and sworn before me on this (:)._ ay of 91, (l , 19 June 28,1999.6288 4,o 111f11///l e YK• '-q1 j,OCA c i kt° E'-. f' Notary Public of the State of Washington Y: %NOTARY residing in Renton 0—King County, Washington P Sot Pi1/AS,,,%‘e‘ NOTICE OF ENVIRONMENTAL DETERMINATION ENVIRONMENTAL REVIEW COMMITTEE RENTON, WASHINGTON The Environmental Review Committee (ERC) has issued a Determination of Non-Significance - Mitigated for the following project under the authority of the Renton Municipal Code. LA PIANTA REZONE AND COMP PLAN AMENDMENT L U A-99-0 54,C PA,EC F,R Amend the Land Use Map to change 74.2acres of this property from Residential Single Family with RMH zoning to Residential Options(RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN) with R-14 zoning, and .9 acres to Convenience Commercial (CC) with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. Location: South of NE 3rd East of Edmonds Ave. Appeals of the environmental determination must be filed in writing on or before 5:00 PM July 12, 1999. Appeals must be filed in writing together with the required $75.00 application fee with: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code Section 4-8-11 B. Additional information regarding the appeal process may be obtained from the Renton City Clerk's Office, (425)-430-6510. Publication Date: June 28, 1999 Account No. 51067 dnsmpub.dot STAFF City of Renton REPORT Department of Economic Development, Neighborhoods, Strategic Planning ENVIRONMENTAL REVIEW COMMITTEE A. BACKGROUND ERC MEETING DATE June 22, 1999 Project Name Amended La Pianta Rezone and Comprehensive Plan Amendment Applicant La Pianta Limited Partnership,Ms.Ann Nichols File Number LUA-099-054,CPA,ECF Project Manager Rebecca Lind This application is amended to request a Land Use Map Amendment changing 74.2 acres of Project Description this property from Residential Single Family with RMH zoning to Residential Options(RO) with R-10 zoning,and 20 acres to Residential Planned Neighborhood(RPN)with R-14 zoning,and.9 acres from Residential Multi-family Urban to Convenience Commercial with CC zoning.The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn.A development agreement is proposed by the applicant to limit development in the following ways. a. Development to be restricted to a maximum of 490 units b. The overall number of flats to be limited to 78 units and the number of flats in any building to 6 units. c. The total impervious surface coverage to be 45 acres as shown in the May 26, 1999 memo from Dodds Engineers Attachment 1 d. Total traffic generation from all land uses to be no greater than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers ITE Manual as shown in the memo from David I Hamlin and Associates received May 27, 1999 by the Building Division.(Attachment 2) Project Location South of NE 3'I,East of Edmonds Ave.(extended) Exist.Bldg.Area gsf NA Proposed New Bldg.Area gsf NA Site Area 96 acres Total Building Area gsf NA RECOMMENDATION Staff Recommend that the Environmental Review Committee issue a Determination Non Significance Mitigated June 22, 1999. B. RECOMMENDATION Based on analysis of probable impacts from the proposal,the information submitted by the applicant in the revised application,and on the analysis in the Final Environmental Impact Statement for the Land Use Element of the Comprehensive Plan February 1993.(Attachment 3),staff recommends that the Responsible Officials make the following Environmental Determination: City of Renton ED/N/SP Department Envirn ztal Review Committee Staff Report LA PIANTA LUA-99-054, CPA,ECF REPORT AND DECISION OF JUNE 22, 1999 Page2 of 4 DETERMINATION OF DETERMINATION OF NON-SIGNIFICANCE NON-SIGNIFICANCE-MITIGATED. Issue DNS with 14 day Appeal Period. XX Issue DNS-M with 14 day Appeal Period. Issue DNS-M with 15 day Comment Period followed by a 14 day Appeal Period. C. MITIGATION MEASURES 1. A Development agreement be approved by the City and recorded as a restrictive covenant running with the title of the property.The Development Agreement shall stipulate as follows: Development to be restricted to a maximum of 460 units. The overall number of flats to be limited to 78 units and the number of flats in any building to be limited to 6. The total impervious surface coverage to be 45 acres as shown in the May 26, 1999 memo from Dodds Engineers. Total traffic generation from all land uses to be not greater than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers ITE Manual as shown in the memo from David I Hamlin and Associates. 2. The portion of the property proposed for Residential Planned Neighborhood Designation which is located in Zone 1 of the Aquifer Protection Area shall be limited to 10 dwelling units per net acre. D. ENVIRONMENTAL IMPACTS In compliance with RCW 43.21 C. 240,the following project environmental review addresses only those project impacts that are not adequately addressed under existing development standards and environmental regulations. Has the applicant adequately identified and addressed environmental impacts anticipated to occur in conjunction with the proposed development? 1.Earth Impacts: None at this time. Application is for Comprehensive Plan Designation change and rezone. Site specific review would need to occur at the time a development application is submitted. Mitigation Measures: None 2.Land Use Impacts: The theoretical density on the site is calculated at 369 single family units and 18 multi-family units based on the standard city methodology utilizing vacancy,market,sensitive area and pubic facility discounts.The applicant submitted a theoretical site plan showing how 413 single family units could be accommodated on the site.The single family trip generation with 413 conventional single family units or manufactured homes and 18 multi-family units would be 4071 trips.Comparison of daily trips based on the report submitted by David Hamlin(Attachment 2)shows that proposed trip generation for the 460 units proposed in the application materials would be 3582 trips. The applicant requests RPN and RO Land Use designations limited by a development agreement up to a maximum of 490 dwelling units. The development agreement would substantially limit both the maximum density and the number of traffic trips that could be generated on the site. The maximum density which could be realized with the RPN and RO land use without the development agreement is 883 attached residences assuming use of bonus provisions. The increased trip generation with the maximum development scenario would be approximately 4742 trips. The proposed development agreement would be a mitigating factor in reducing the potential impact created by the maximum density on the site. While the applicant's proposal is to cap the potential development at 490 units,the staff recommendation is to lower the cap to 460 units due to concerns over the increased density which can be accommodated on this site.Thois increased density could have a greater impact on aquifer protection and traffic generation. It is further recommended that should policy discussions during the Comprehensive Plan Amendment review by the Planning Commission and City Council result in a recommendation to increase this cap,then the application is be return to the Environmental Review Committee for further review of the possible environmental impacts of this increased density. STAFFREP4 City of Renton ED/N/SP Department Enviri ital Review Committee Staff Report LA PIANTA LUA-99-054,CPA,ECF REPORT AND DECISION OF JUNE 21, 1999 Page3 of 4 3. Air The site was included in a Land Use Study Area Vehicle Trip Generation Report as part of the Final Environmental Impact Statement for the Land Use Element of the Comprehensive Plan in February 1993. Three alternative land uses were analyzed: Office,Single Family R/4 Mix,and Single Family/Education Institution Center for the McMahon Property Study Area Attachment 3). This study area totals approximately 250 acres including the Mt.Olivet Cemetary,King County shops,office buildings and transfer station and approximately 194 vacant acres. The vacant land was included in the land inventory used in the capacity analysis for the City's 1993 Land Use Element. The potential impacts of traffic for 1150 single family and multi-family units(assuming a 50/50 split in unit types)were analyzed in the FEIS. The proposed Comp Plan/Rezone application represents approximately 96 acres of the study area. Assuming that the capacity analyzed was uniformly distributed within the undeveloped portions of the study area,the subject site would account for 49%of the capacity reviewed in the FEIS,or 564 units. The level of development proposed in the proposed CPA/rezone(with the development agreement)was already accounted for in a review of mixed(50%single family and 50%multifamily)unit types. With the proposed development agreement,the traffic generated by the subject property will not exceed the levels studied in the FEIS for this property. A Comparison of Existing Zoning/Comp Plan,and the La Pianta Proposal with Prior Environmental Review is shown in attachment 5. 4. Water The revised application materials include a storm drainage report prepared for this site,specifically for the Cedar Crest development,a 402 unit manufactured home park with a vested site plan approval on this site. This report included a detailed analysis of drainage and aquifer related issues. This level of analysis exceeds the submittal requirements for non project actions. However the applicants state that the storm drainage analysis already prepared for the Cedar Crest project will be used for a future development proposal on this site,and will be modified as needed to address any future project. Consequently the storm drainage analysis is included as part of this project application. All storm water generated on site is proposed to be infiltrated. Since infiltration of storm water is restricted within APA Zone 1 all of the infiltration facilities for this project are sited within APA Zone 2. Storm drainage will be collected in a tightline conveyance system and directed to the existing water quality/detention/infiltration facility. The storm water will enter a wet pond that will provide water quality enhancement prior to the storm water entering the infiltration pond. The infiltration pond will provide live storage detention to allow the 2, 10 and 100 year/24 hour storm events to be released entirely through infiltration.A downstream analysis is also included in the submittal which addresses an emergency overflow pipe system to convey storm water that would be discharged in the event of a failure. This pipe discharges into a pond located adjacent to N.E.3rd Street and east of Blaine Ave.NE adjacent to Mount Olivet Cemetary. Storm water from this site enter into a system of pipe running along N.E 3'd and eventually discharge into a system near I-405. The downstream flow path was analyzed by Triad Associates in October 1998,and was reported as operating correctly. Documentation of this analysis is provided in the appendices to the Storm Drainage report for Cedar Crest.A summary of this document is provided in Attachment 4. In addition,the applicant analyzed potential impervious surface for a conceptual development project. This analysis is presented in the memo from Dodds Engineers dated May 26, 1999(Attachment 1). On the basis of this analysis,the applicant is proposing to limit the amount of impervious surface for future development on the site to the same level that was approved for the Cedar Crest Manufactured Home site plan. A cap of 45 acres of impervious surface is proposed. Public Facilities Pedestrian Facilities Pedestrian access will be provided to the site along the sidewalk developed as part of the extension of Edmonds Ave. Internal pedestrian circulation would be required of a future development project in compliance with Renton Municipal Code Title IV Section 4-6-060 Street Standards. Parks Comments from the Parks Department are attached. A parks impact feet of$530.76 for each single family lot and 354.51 for each multi-family unit are recommended for the eventual development project which will occur on this site. E.COMMENTS OF REVIEWING DEPARTMENTS STAF=REP4 City of Renton ED/N/SP Department Envirr Vital Review Committee StaffReport LA PIANTA LUA-99-054, CPA,ECF REPORT AND DECISION OF JUNE 22, 1999 Page4 of 4 The proposal has been circulated to City Departmental/Divisional Reviewers for their review. Where applicable, these comments have been incorporated into the text of this report as Mitigation Measures and/or Notes to Applicant. Copies of all Review Comments are contained in the Official File. x Copies of all Review Comments are attached to this report. Environmental Determination Appeal Process Appeals of the environmental determination must be filed in writing on or before 5:00 PM July 12, 1999. Appeals must be filed in writing together with the required 75.00 application fee with: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98055. Appeals to the Examiner are governed by City of Renton Municipal Code Section 4-8-11 B. Additional information regarding the appeal process may be obtained from the Renton City Clerk's Office, (425)-430-6510. STAF FREP4 ATTACHMENT 1 DODDS ENGI MEMO CITY OF RENTON RECEIVED Date: May 26, 1999 MAY 2 7 1999 DEI Project No. 99015 BUILDING DIVISION To: David Halinen From: Craig Krueger Re: La Pianta Comp Plan Amendment/Rezone Impervious Surface Calculations Attached you will find the detention calculations prepared by another consultant for Basins 1 and 2 for the approved Cedar Crest development (402 manufactured homes). For the purposes of this analysis, we have assumed that many of the impervious surface calculations will be consistent for the proposed mixed use plan since the road pattern, road width, water quality ponds, etc. will remain very similar to the Cedar Crest layout. The areas that will change are 1) the "impervious areas on lots" and 2) the RV Storage Area,which is being deleted from the development. Below you will find a comparison of the "impervious area on lots" for the two basins which compares the assumptions made for Cedar Crest against the mixed use proposal with townhouses, carriage flats, and single family homes. You will note that, while the mixed use proposal calls for an increase in the number of units, the size of the footprints for the townhouses, carriage flats and alley homes are much smaller than the 2876 square feet assumed for the manufactured homes. Basin #1 Comparison of impervious area on lots. Approved plan 2876 sf x 209 lots = 13.80 ac. Proposed Concept Village A 101 TH x 1700 sf/TH = 3.94 ac. Village B 82 TH x 1700 sf/TH = 4.96 ac. 78 carriage flats x 980sf/DU 1400 if of 20' wide alley= 0.64 ac. Total = 9.54 ac. Planning•Engineering•Surveying 4205-148th Avenue NE Suite 200 Bellevue,Washington 98007 Tel.425-885-7877 Fax.425-885-7963 99015L##1.doc 5/27/99 Mr. Dave Halinen Pg: 2 Additional reduction in impervious area RV storage area deleted= 1.94 ac Basin #2 Comparison of impervious are on lots Approved plan 2876 sf x 200 lots= 13.20 ac. Proposed concept Village C 46 SFD @ 2876/DU= 3.10 ac. Village D 76 trad. @ 2000/DU= 6.63 ac. 76 alley @ 1800/DU Alleys @ 12001f x 20'wide= 0.55 Total= 10.28 ac. Total impervious area for approved plan 45.04 ac. Total impervious area for proposed plan 35.90 ac. Net reduction 9.14 ac. Net %reduction 20% ATTACHMENT 2 a71' Do liam0aun A GZ,ozOopla. 3 traffic design transportation planning 1319 Dexter Avenue North Seattle,Washington 98109 206)285-9035 Suite 270 FAX 285-6345 TABLE 1 TRIP GENERATION COMPARISON LA PIANTA SITE - RENTON CONVENTIONAL SF LOT CAPACITY (UNDER R-8 PLANNED RESIDENTIAL REGULATIONS) & APT. DEVELOPMENT DISTRIBUTION CAPACITY (UNDER RM-I AS OF 05/27/99 REGULATIONS) 239 SF 221 TOTAL 413 SF 18 MF TOTAL TIME PERIOD LOTS T.H. TRIPS LOTS UNITS TRIPS Daily 2287 1295 3582 3952 119 4071 AM Peak Enter 45 16 61 78 1 79 Exit 134 81 215 232 8 240 Total 179 97 276 310 9 319 PM Peak Enter 154 80 234 267 7 274 Exit 87 39 126 150 4 154 Total 241 119 360 417 11 428 NOTE: The trip rates for ITE Land Use Code 210, Single-Family Detached Housing, were used for the ramblers in Village A, all of Villages C and D (which are entirely single-family detached) , and the 413 single-family lots considered for comparison purposes. The trip rates for Land Use Code 230, Residential Condominium/Townhouse, were used for the proposed townhouses and stacked flats in Villages A and B. Land Use Code 220, Apartments, was used for the 18 apartments (allowed under the RM-I regulations) . CITY OF:R NTON RECEIVED 11Ay 2 7 1999 BUILDING DIVISION ATTACHMENT 3 LAND USE STUDY AREAS VEHICLE TRIP GENERATION REPORT Introduction The Renton City Council has requested City staff to study alternative land uses for three areas in Renton: the North Renton area including the adjacent Airport Way area, the McMahon Property area in East Renton and the Talbot Road area in Southeast Renton. The following is the traffic analysis element of the study. This report provides information on the estimated vehicle trips generated by each alternative land use proposed for each of the three study areas, compares the vehicle trips generated by each land use alternative and presents the findings resulting from the comparison. Study Areas and Land Use Alternatives The following information on the study areas and land use alternatives was provided by the Long Range Planning Section of the City of Renton. North Renton/Airport Way Study Area: The North Renton area, as shown on Figure 1, is bounded by Logan Avenue North, North 6th Street, Garden Avenue North, North 4th Street, North 3rd Place, Bronson Way and the Cedar River. The three land use alternatives identified for this area are presented in Table 1. Land Use Alternative 1, the Planning Commission proposal, has a nearly even split between single family (441 units) and multi-family use (444 units) and a majority of financial, insurance, real estate services (office) mixed with some retail, education, manufacturing and warehouse uses. Jobs and building square footage under this proposal total 2836 and 995,000 respectively. Land Use Alternative 2, the neighborhood proposal, represents existing land use and assumes no change in land use in future years. Land Use Alternative 2 has a nearly even split between single family (441 units) and multi-family (415 units) use and a majority of financial, insurance, real estate services office) use mixed with some retail, education, manufacturing and warehouse uses. Jobs and building square footage under this proposal total 2199 and 707,000 respectively. The main difference between Land Use Alternative 1 and 2 is the amount of retail, education, manufacturing and warehouse use (311,000 square feet in Alternate 1 and 117,000 square feet in Alternate 2). Land Use Alternative 3, representing requests, proposes a predominance of multi-family (923 units), financial, insurance, real estate services (office) and retail uses. Total jobs and building square footage is 3,324 and 1,112,000 respectively. The Airport Way area, also shown on Figure I, is bounded by Airport Way, Logan Avenue South, South Tobin Street and Lake Avenue South. The three land use alternatives identified for this study area are presented in Table 1. Land Use Alternative 1, existing use, assumes the existing single and multi-family uses and the existing financial, insurance, real estate services (office), and retail and manufacturing uses wll not change in future years. Land Use Alternative 2, the Planning Commission proposal, assumes a more intense mix of financial, insurance,real estate services (office) and retail and manufacturing uses with some multi-family use (26 Units) only. Jobs and building square footage in Land Use Alternative 2 total 505 and 208,000 respectively, compared to 190 jobs and building square footage of 86,000 in Land Use Alternative 1. Land Use Alternative 3, the commercial/single family proposal, assumes a predominance of single family units (39) and one-half the jobs 252) and building square footage (104,000) for financial, insurance, real estate services (office) and retail and manufacturing uses than proposed in Land Use Alternative 2. McMahon Property Study Area: This area, as shown on Figure 2, is located east of Blaine Avenue NE and between NE 3rd/4th Street and the top of the bluff above Maple Valley Highway. The three land use alternatives identified for this study area are presented in Table I. Land Use Alternative 1 proposes a predominance of financial, insurance, real estate services (office) with some manufacturing and a lesser amount of retail use. Total jobs and square footage for the mixed office, retail, manufacturing uses are 7028 and 2,425,000, respectively. Land Use Study Area Page 2 Vehicle Trip Generation Report December 16, 1992 Residential use is not proposed in this alternative. Land Use Alternative 2 is a 50-50 mix of single family andmulti-family dwellings. Land Use Alternative 3 has approximately 90% of the area as education use with the remainder as retail, financial, insurance, real estate services (office)and single family residential uses. Total jobsandsquarefootagefortheeducation, retail and office uses are 4279 and 2,278,000, respectively. Also included in Table 1 are estimated jobs and building square footage for existing land uses in this study area. Talbot Road Study Area: This area, as shown on Figure 3, is located north of South 192nd Street and between SR 167 and the top of the hill east of Talbot Road. The two land use alternatives identified for this study area are presented in Table 1. Land Use Alternative 1 is totally multi-family use while Land Use Alternative 2 is a 50-50 mix of single family and multi-family units. Also included in Table 1 is the estimated dwelling units for the existing residential use in this study area. Trip Generation Estimates of dwelling units,jobs and building square footage for the land use alternatives in the three study areas were provided by the Long Range Planning Section of the City of Renton. Trip generation rates for each land use are based on information in the Institute of Transportation Engineers (ITE) Trip Generation manual (fifth edition, 1991). The trip rate per square foot of building floor area was used because the Trip Generation manual did not provide information on trip rate per employee for several of the land uses. Detailed listings of land use data and estimated trip generated by each land use alternative in the three study areas are provided in Appendix A. Table 2 summarizes the trip generation estimates of daily and PM peak hour trips for each land use alternative in the study areas. These estimates represent average daily and PM peak hour trips and indicate future traffic demands on the street system after "build-out" of each land use alternative. Also included in Table 2 are the estimated daily and PM peak hour trip generation for the existing land uses in each study area. Trip Generation by Land Use Alternative-Summary of Findines North Renton Study Area: Land Use Alternative 2 (Neighborhood Proposal) is estimated to generate the least daily and PM peak hour trips (14,780 and 1660 respectively) of the three land use alternatives. (It should be noted that the Neighborhood Proposal is representative of existing conditions.) Land Use Alternative 1 (Planning Commission Proposal) is estimated to generate 18,440 daily and 2130 PM peak hour trips. Land Use Alternative 3 (Requests) is estimated to generate the most daily and PM peak hour trips (25,050 and 2930, respectively). Airport Way Study Area: Land Use Alternative 1 (representing existing conditions) is estimated to generate the least daily and PM peakhourtrips (2200 and 270, respectively) of the three land use alternatives. Land Use Alternative 3 (Planning:Commission proposal) is estimated to generate 3010 daily trips and 380 PM peak hour trips. Land Use Alternative 2 (Commercial/Single Family) is estimated to generate the most daily and PM peak hour trips 5130 and 650, respectively). McMahon Property Study Area: aimmomummouni Land Use Alternative 2 (SF/4 mix) is estimated to generate the least daily and PM peak hour trips (8510 and 840, respectively) of the three land use alternatives. Land Use Alternative 1 (office) is estimated to generate 24,020 daily trips and 3110 PM peak hour trips. Land Use Alternative 3 (Education - Institution) is C A Q CITY OF RENTON DEPARTMENT OF PLANNING, BUILDING & PUBLIC WORKS 21.:41d__________LL LAKE WASH/NGTO V 1 s ,. I. f i A s•zt, L[K ?••,,. E „,., c 1 1 ../cr P-.2 a. simil t 1,E 7 ----\?:).\ 7th 1 \ 1 ; sl C..sj Att x R Hft5'i te. 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' f?(_ ._--_ i_ FIGURE 3 APPENDIX A Study Area Land Use and Estimated Trip Generation TABLE A-1 NORTH RENTON /AIRPORT WAY STUDY AREA Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Airport Way Alternative' - Existing Use Single Family d.u. 18 11.8 212 1.28 23 Multi Family d.u. 19 10.7 203 0.82 16 Retail 1000 gsf 32 40.67 1300 4.93 158 Manufacturing 1000 gsf 39 3.55 138 0.75 29 Office(FIRES *) 1000 gsf 15 23.1 347 3.16 47 Warehouse 1000 gsf 0 Total: 2200 273 Airport Way Alternative 2 - Planning Commission Proposal Single Family d.u. 0 Multi Family d.u. 26 10.11 263 0.77 26 Retail 1000 gsf 91 40.67 3.700 4.93 449 Manufacturing 1000 gsf 56 3.64 203 0.75 42 Office(FIRES *) 1000 gsf 61 15.84 966 2.12 129 Warehouse 1000 gsf 0 Total: 5132 646 Airport Way Alternative 3 - Commercial/Single Family Single Family d.u. 39 11 429 1.18 46 Multi Family d.u. 13 5 150 0.86 11 Retail 1000 gsf 45 40.67 1830 4.93 223 Manufacturing 1000 gsf 28 3.41 96 0.75 20 Office(FIRES *) 1000 gsf 31 19 509 2.57 80 Warehouse 1000 gsf 0 Total:3014 380 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units gsf = gross square footage of floor area Source: Daily and PM peak hour trip rates per unit based on information in the Institute of Transportation Engineers 1TE)Trip Generation manual (5th edition, 1991) aL.\t•3'../A:TA3rb TABLE A-1 I NORTH RENTON /AIRPORT WAY STUDY AREA Summary of Land Use and Estimated Trip Generation l DAILY DAILY PM PEAK PM PEAK LAND USE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS North Renton Alternative 1 - Planning Commission Proposal I Single Family d.u.441 9.18 4,048 0.94 412 Multi Family d.u.445 6.09 2.710 0.55 250 Retail 1000 gsf 108 40.67 4,390 4.93 532 Education 1000 gsf 46 11.2 515 0.28 13 Manufacturing 1000 gsf 111 3.77 418 0.75 83 Office(FIRES *) 1000 gsf 684 8.77 6,000 1.12 766 Warehouse 1000 gsf 46 7.76 357 1.67 78 Total: 18,438 2,134 1 North Renton Alternative 2 - Neighborhood Proposal Single Family d.u.441 9.18 4,048 0.94 415 Multi Family d.u.415 6.16 2,556 0.56 232 Retail 1000 gsf 58 40.67 2,359 4.93 286 Education 1000 gsf 24 13.46 323 0.28 7 1 Manufacturing 1000 gsf 35 3.51 123 0.75 26 Office(FIRES *) 1000 gsf 590 9.10 5,369 1.17 690 Warehouse 1000 gsf 0 Total: 14,778 1,656 North Renton Alternative 3 Requests Single Family d.u. 42 11 462 1.20 50 1 Multi Family d.u.923 5.34 4,929 12,974 0.48 443 Retail 1000 gsf 319 40.67 4.93 1573 Education 1000 gsf 0 1 Manufacturing 1000 gsf 16 3.85 61 0.75 12 Office(FIRES *) 1000 gsf 777 8.53 6,628 1.09 847 Warehouse 1000 gsf 0 Total: 25,054 2,925 North Renton - Existing Land Use i Single Family d.u.441 9.18 4,048 0.94 415 Multi Family d.u.415 6.16 2,556 0.56 232 Retail 1000 gsf 58 40.67 2,359 4.93 286 Education 1000 gsf 24 13.46 323 0.28 7 Manufacturing 1000 gsf 35 3.51 123 0.75 26 Office(FIRES *) 1000 gsf 590 9.10 5,369 1.17 690 Warehouse 1000 gsf 0 Total: 14,778 1,656 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units gsf = gross square footage of floor area Source: Daily and PM peak hour trip rates per unit based on information in the Institute of Transportation Engineers ITE)Trip Generation manual (5th edition, 1991) KL\1Q/w..A:TA.Vjb TABLE A-2 McMAHON PROPERTY Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE TYPE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Alternative 1 - Office Single Family d.u. 0 Multi Family d.u. 0 Retail 1000 gsf 158 40.67 6,425 4.93 780 Education 1000 gsf 0 Manufacturing 1000 gsf 580 3.85 2,235 0.75 435 Office(FIRES *) 1000 gsf 1687 9.11 15,370 1.12 1890 Warehouse 1000 gsf 0 Total: 24,020 3105 Alternative 2 - Single Family/4 Mix Single Family d.u.575 9 5,175 0.91 525 Multi Family d.u.575 5.82 3,345 0.54 310 Retail 1000 gsf 0 Education 1000 gsf 0 Manufacturing 1000 gsf 0 Office(FIRES *) 1000 gsf 0 Warehouse 1000 gsf 0 Total: 8,510 835 Alternative 3 - Single Family/Education-Institution Center Single Family d.u. 45 11 495 1.17 53 Multi Family d.u. 0 Retail 1000 gsf 96 40.67 3,905 4.93 473 Education 1000 gsf 1925 12.87 24,775 1.06 2040 Manufacturing 1000 gsf 0 Office(FIRES *) 1000 gsf 257 11.24 2,890 1.47 379 Warehouse 1000 gsf 0 Total: 32,065 2,945 Existing Land Use Manufacturing 1000 gsf 6 3.33 20 0.75 5 Office(FIRES*) 1000 gsf 59 15.84 930 2.12 125 950 130 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units gsf = gross square footage of floor area R L Mi•31-../A:TA:.j b TABLE A-3 TALBOT ROAD STUDY AREA Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE TYPE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Alternative 1 -Multi Family Multi Family d.u. 940 5.62 5300 0.51 480 or Multi Family d.u. 1210 5.37 6500 0.49 590 Alternative 2 - Single Family 14 Mix Single Family d.u. 305 9.45 2,880 0.97 296 Multi Family d.u. 305 6.51 1,985 0.58 177 Total: 4,865 473 or Single Family d.u. 450 9.11 4100 0.87 390 Multi Family d.u. 450 6 2700 0.54 240 Total:6800 630 Existing Land Use Single Family d.u. 25 12 300 1.2 30 Multi Family d.u. 0 Total: 300 30 ATTACHMENT 4 EDAR PHASES I & II CITY OF RENTON RECEIVED Renton, Washington mAY 2 7 1999 BUILDING DIVISION Storm Drainage Report Prepared by: Scott R. Borgeson ooof wAsy, 'YeReviewedby:f ' Donald J. Hill, P.E. 4 ye ; - 25380ed;1ONAL Arm EXPIRES 6/81 qqIBM TRIAD ASSOCIATES Februar 1 1 1 999 TRIAD JOB # 95 - 1 23 INTRODUCTION The proposed project is to construct a 401 site manufactured/modular home community on approximately 127 acres located north of and adjacent to Maple Valley Road (State Route 169) and south of N.E. Third Street. The project is separated into four construction phases. This report has been prepared to address storm drainage design for Phases 1 and 2. See the report titled "Cedar Crest— Phases III & IV — Storm Drainage Report"for storm drainage design and analysis related to Phases 3 and 4. The site is bordered on the west by the recently constructed extension of Edmonds Avenue N.E. and the Plat of La Colina. The site is bordered on the east and northeast by a King County facility. More generally, the site is located in Section 16, Township 23 North, Range 5 East, W.M. in the City of Renton, King County,Washington. Please refer to the Vicinity Map located below. Approximately 85 acres of the site will be developed, while 42 acres will remain native. The site has been used as a gravel pit, which has been mined of most of the useful coarse gravel materials. The underlying foundation material is primarily fine to coarse-grained glacial outwash,which allows for good infiltration of surface water. A detailed description of the on-site soils can be found in the Hydrogeologic and Geotechnical Services/Report prepared by Geo Engineers, Inc. in October, 1994. This report is located in the Appendix. NF PARK °R airApo-N TAMI SITE sl NE 4TH ST iy'e 38° GREENWOOD CEMETERY CITY OF RENTON 9 O VICINITY MAP Not to Scale STORM DRAINAGE REPORT FOR CEDAR CREST—Page 1 Phases 1 &2 DRAINAGE CONCEPT The storm drainage system for the proposed project was designed with reference to standards found within the 1990 King County Surface Water Design Manual (KCSWDM) and as shown on the Grading & Utility Plans that accompany this report. Currently the majority of the on-site and off-site (upstream) stormwater infiltrates into the ground. The remainder is conveyed,through channels that were constructed as shown on the Grading/Temporary Erosion and Sedimentation Control Plans (previously approved by the City of Renton), to a Type II catch basin located approximately 500 feet south of the northwest corner of the site. From this structure, the water flows via a 30-inch underground pipe to an open basin that is located just outside the northwest corner of the site. A description of the existing conveyance system downstream from this point can be found in the Downstream Analysis section that follows this section. The site lies within two separate City of Renton Aquifer Protection Zones (see City of Renton Aquifer Protection Areas on the following page). The boundary line between the two zones runs east to west across the property, segmenting the southern portion of the property into APA Zone 1, while the northern portion is classified as APA Zone 2. This division line is also shown on the Pipe Tributary Area Exhibit,located in the Appendix. Per the Conditions of Approval for Cedar Crest (see Hearing Examiner's Report and Decision located in the Appendix), all of the stormwater generated on-site must be infiltrated. Since infiltration of stormwater is restricted within APA Zone 1, all of the infiltration facilities for this project have been sited within APA Zone 2. The site has been divided into two basins, with Basin#1 covering the northern portion of the site and both Phases 1 and 2 of the project. Basin#2 covers the remainder of the site, and is coincident with Phases 3 and 4 of the project. The areas tributary to each sub-basin within Basin #1 can be seen on the Pipe Tributary Area Exhibit(see Appendix). This report will focus specifically on the storm drainage issues of Basin#1. The stormwater generated within Basin#1 will be collected in a tightline conveyance system and directed to the existing water quality/detention/infiltration facility, located along the western property boundary of the site and south of the proposed Cedar Crest Parkway, hereafter referred to as Pond A. The stormwater will first enter a three-celled wetpond(cell 2 and cell 3 are existing)that will provide water quality enhancement prior to the stormwater entering the infiltration pond. The infiltration pond will provide live storage detention to allow the 2, 10,and 100-year/24-hour storm events to be released entirely through infiltration. At the recommendation of Geo Engineers, Inc. (see Appendix), an approximately 78,000 s.f., 4' deep infiltration blanket has already been constructed as a part of the construction of Pond A, extending to the north from the northwest corner of Pond A, in order to provide ample area to distribute the infiltration and therefore increase the effective percolation rate. Finally, there are two bypass areas of Basin#1, which will be conveyed via the Emergency Overflow Pipe to the natural discharge point in the northwest corner of the site. One area is 4.30 acres lying along the STORM DRAINAGE REPORT FOR CEDAR CREST—Page 2 Phases 1 &2 DOWNSTREAM ANALYSIS As described previously, the stormwater generated on-site will all be infiltrated on-site. However, an Emergency Overflow Pipe system has been designed and installed to convey the stormwater that would be discharged by Pond A(and/or also Pond B/C which will serve Phases 3 and 4) in the event of failure. This pipe is also designed to convey the runoff from the on-site bypass areas and the off-site(upstream) tributary area. The 30-inch diameter pipe follows the alignment of Road A (Cedar Crest Parkway) until it makes a jog to connect to a type II catch basin with solid cover that is located approximately 500 feet south of the northwest corner of the site. This structure is labeled as CB OV-IA on both the Pipe Tributary Area Exhibit see Appendix)and the Downstream Analysis Exhibit(next page). From this structure, the stormwater continues through approximately 157 feet of 30-inch underground H.D.P.E.pipe to an open pond that is located just outside the northwest corner of the site. Stormwater from this basin overflows into a 48-inch diameter corrugated metal pipe riser and flows through approximately 168 feet of 48-inch corrugated metal pipe at roughly a 5 percent slope. This pipe discharges into a drainage channel that is well defined and heavily vegetated,and travels westerly for approximately 300 feet. Here it discharges into an open pond that is approximately 100 feet by 50 feet and approximately 3 to 5 feet deep. The pond is located along the south margin of N.E. 3'i Street, and east of Blaine Avenue N.E., adjacent to the entrance into the Mount Olivet Cemetery. The stormwater exits this pond through an overflow structure with a birdcage,,and enters into a system of approximately 1,250 feet of pipe (18" followed by 24") that runs along the southern margin of N.E. 3`d Street,eventually discharging into a system near 1-405. By this point,the Cedar Crest site makes up less than 10 percent of the contributing basin,and so drainage systems, which were further downstream, were not studied. This downstream flow path was analyzed while conveying heavy rains during a site visit by Triad Associates on October 13, 1998. The drainage course was working properly and no signs of erosion or flooding problems were evident. A similar summary of downstream conditions is in the Level I Drainage Study and Preliminary Storm Drainage Report by Barghausen Consulting Engineers,Inc.,located in the Appendix. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 5 Phases 1 &2 northeast site corner. It will remain as an undeveloped slope. The other area is a 1.47 acre naturally graded gully area in the northwest corner of the site that is significantly lower than the remainder of the site. The goal of this proposed drainage system is to provide infiltration in order to recharge groundwaters, to prevent adverse impacts to downstream areas,and to maintain the overall hydrologic balance of the site and surrounding area. Currently the off-site (upstream) stormwater (3.01 acres), the on-site generated stormwater that does not infiltrate, and some of the groundwater base flows contribute to the downstream flow that discharges at the northwest corner of the site. In order to maintain this flow, the off-site upstream) and the bypass (upstream) flows will be collected by a gravel trench drain that will follow the toe of the slope that runs along the east property line. Stormwater flows from both above and below ground will be captured by this system and channeled to the site's natural discharge point via the emergency overflow pipe. The Conditions of Approval questioned how the project site and neighboring areas would be affected by infiltrating stormwater in the infiltration ponds rather than distributing it over the entire site. It appears that the stormwater that infiltrates in the existing condition,both on-site and off-site (upstream), flows naturally towards the northwest corner of the site. In our opinion, it appears that the stormwater infiltrated on-site in the developed condition will follow the same general flow patterns toward the northwest corner of the site, and will help to maintain the existing downstream flows. This is confirmed by the location of the infiltration facility, where the infiltration pond (Pond A) and the adjoining infiltration blanket are situated back from the west property line of the site to allow the infiltrated flows to spread out as the flows follow the apparent westerly gradient. This is also confirmed by the orientation of the infiltration facility where Pond A and the infiltration blanket are oriented and spread out in the north-south direction to better disperse the infiltrated flows so that they more closely match the existing condition. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 4 Phases 1 &2 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: COMMENTS DUE: JUNE 8, 1999 APPLI(;ATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJE CT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCA1 ION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension SITE A REA: 96.2 acres I BUILDING AREA(gross): N/A SUMM\RY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with RMH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Convenience Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres )f Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. VVIRONMENTAL IMPACT(e.g.Non-Code) COMMENTS Elemer t of the Probable Probable More Element of the Probable Probable More Enviroh iment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts impacts Necessary Earth - Housing Air Aesthetics Water Light/Glare Plants Recreation Land/S lorellne Use Utilities Animal. Transportation Envlror mental Health Public Services Energy Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. POLICY-RELATED COMMENTS l° 4 Q y530. 7C, 5// 77)77 0 7/___ v/ c. 'ODE-RELA TED COMMENTS o% G Ztiu G2-'Gc_ We 'e reviewed this application with particular attention to those areas in which we have expertise and have Identified areas of probable impact or are where additional information is needed to prop assess this proposal. gnats re of Director or Authoriz ep sentative Date Rev.14 Comprehensive Plan Amendment 99 —M-3 Attachment B: Neighborhood Detail & Existing Zoning i — I 5c u C R - 10 R - 10 Q., a R14— I 11 1 i R- - ILCP ) RMH 1 1 R - 81 RMH 9 4 R C N<,,,,, i a;/ 1 7, _ N t „/ 1 1 i.1.7,E.- ,1-_ 17777 i',H 8 ! r--7-7-_,,,,, 7----------------------. '''''\. 17-7. 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E I71 -.J/J 1 O. r MLe a u s.ww.n r T•dn cd 5•rvic• CITY OF RENTON CITY LIMITS e• ?knniLysuSdu.p/P:bk Work,a. 26:'°„";,°;""•' AQUIFER PROTECTION AREAS PRODUCTION WELL 1IJ 2 iJ COMPREHENSIVE PLAN MAP AMENDMENT 99 M-3,Revised Applicant La Pianta Limited Partnership 3 J Proposal Change 95 acres Residential SF with RMH zoning to Residential Options with R-10 zoning 74.2 acres RPN with R-14 zoning 20 acres Convenience Commercial with CC zoning.92 acres JJ Location NE 3rd/4th Extension of Edmonds Former Gravel Pit 5 'J Vested Project 402 unit senior manufactured home park 45.04 acres of impervious surface 6 'J Application Amended Text Amendment for senior housing Withdrawn RPN area scaled back to 20 acres Commercial component specific map request 7 O Project Concept: 4 villages Village A 101 units 40 detached 61 townhouse Village B 160 townhouse units Village C 47 detached Village D 152 detached 8 ;J Development Agreement 490 Units 78 flats in buildings of 6 units max Limit impervious surface to 45.04 acres Maximum 4,071 daily trips 9 J Issues Additional Density Attached unit types Commercial uses 10 JJ No staff analysis completed 11 0 facitaire 5 Comparison of Existing Zoning/Comp Plan,Cedar Crest,and La Pianta Proposals with Prior Environmental Review. June 18, 1999 Existing Comp Plan/Zoning Single Family Total Development Peak Hour Trips Comp Plan Designation R-8 zoning 413 SF, 18MF 4071 RMU zoning 413 SF, 18MF 4071 Vested Site Plan Cedar Crest Total Development Peak Hour Trips 402 Senior Manuf. 112.5 Homes Prior Environmental Review 1993 Comp Plan Total Development Peak Hour Trips EIS Alt. 1 Office 3,443 jobs 11,760 Alt 2 SF/MF Mix 564 units 4,169 Alt 3 2095 jobs/22 units 15,714 SF/Institution Proposal La Pianta Total Development Peak Hour Trips Original RPN/RO 883 4742 reviewed by ERC units/convenience 5/19 commercial Revised 490 units 4071 RPN/RO/CC with 78 flats in bldg.of 6 development units agreement Vested Site Plan convenience commercial Project"concept" 460 units 50% 3582 detached CITY OF RENTON PLANNINGBUILDING/PUBLIC WORKS MEMORANDUM DATE: June 11, 1999 TO: Rebecca Lind FROM: Sonja J. Fesser SUBJECT: La Pianta Rezone & Comprehensive Plan Amendment Review Comments Bob Mac Onie and I have reviewed the above referenced submittal and have no comments at this time. We appreciate the opportunity to be appraised of the proposed changes for this project, and when legal descriptions are submitted for the proposed rezones, we will be happy to review them. ATS SERVERYSZCOMMONW:\SFESSER\LAPIANTLDOC Washington State Northwest Region Department of Transportation 15700 Dayton Avenue North P.O. Box 330310 Sid Morrison Seattle,WA 98133-9710 Secretary of Transportation 206)440-4000 June 9, 1999 RECEIVED Rebecca Lind J U N 1 4 1999CityofRenton Strategic Planning Division ECONOMIC G BORHOODS. MENT, 1055 S Grady Way AND STRATEGIC PLANNING Renton, WA 98055-3232 RE: LUA-99-054,CPA,ECF,R/LaPlanta Limited Partnership Rezone and Comprehensive Plan Map and Text Amendment(CPA) Dear Ms. Lind: Thank you for giving us the opportunity to review the Notice of Application for the amendment to the Land Use Map,which is located at SE Quadrant of NE 3'd/NE Oland Edmonds Avenue Extension. We have reviewed the subject document and have no comments. The action will not have significant impact on the state highway system. However, future developments in this area as a result of this action may impact state facilities. Please inform us of other applications when they are made so that we may review them. If you have any questions,please contact Don Hurter or John Collins of my Developer Services section. Don's number is(206)440-4664; John's is (206)440-4915. Sincerely, c02 Craig J. Stone, P.E. South King Area Administrator CJS:jc JTC cc: file City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: kOt lCes , COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCATI DN: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension SITE AF EA: 96.2 acres I BUILDING AREA(gross): N/A SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zor ing. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. Et VIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element of the Probable Probable More Element of the Probable Probable More Environrent Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Shc reline Use Utilities Animals Transportation Environrr antal Health Public Services Energy/Historic./Cultural Natural F esources Preservation Airport Environment 10,000 Feet 14,000 Feet B. PC LICY-RELATED COMMENTS C. CC DE-RELATED COMMENTS We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where ad iltional information is needed to properly assess this proposal. Signature of Director or Authofized Representative Date DEVAPP Rev.10/93 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: ponce COMMENTS DUE: JUNE 8, 1999 APPLICATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCAL ION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres BUILDING AREA(gross): N/A SUMM,CRY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with R VIH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Conve hence Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres of Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. EVVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water LighVGlare Plants Recreation Land/SI oreline Use Utilities Animal:Transportation Environ nental Health Public Services Energy,Historic./Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet 7)0 Grniac./ /l Giade,(2 • B. P DLICY-RELATED COMMENTS C. C DDE-RELATED COMMENTS We hay)reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area: where a iditional information is needed to properly assess this proposal. Signatwa of Director or orized Representative Date DEVAPP Rev.10/5 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: V&.'cs COMMENTS DUE: JUNE 8, 1999 APPLICATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 APPLIC ANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJE::',T TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCATION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A SUMM/,RY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with RIi1H Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Conve iience Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres c f Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. El IVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemen of the Probable Probable More Element of the Probable Probable More Environ'rent Minor Major Information Environment Minor Major Information Impacts impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation LandiSh vreline Use Utilities Animals Transportation Environmental Health Public Services Energy/Historic/Cultural Natural resources Preservation Alrport Environment 10,000 Feet 14,000 Feet B. POLICY-RELATED COMMENTS LC(5)'?-1 17 ?,C0 QG vt 30. 7(v c c) cmvi--)ev p54, 7L! (9/-2 5 iv2 r mac_ 1.3 /jam ' C. CODE-RELATED COMMENTS ig4ted We hav reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where a iditional information is needed to pro )assess this proposal. 7/ -/ ci7SignatureofDirectororAuthorizeepsentativeDate DEVAPP Rev.10/9 City of kc,,,on Department of Planning/Building/Public vvurks ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIE'ING DEPARTMENT:—TjyksixAa-hrv‘ COMMENTS DUE: JUNE 8, 1999 APPLICATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 APPLIC ANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind kteL, 11:1" PROJECT TITLE: LaPianta Rezone& Comp. Plan Amendment WORK ORDER NO: 78520sc O 1 Cti LOCAT ON: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension C.`& SITE AREA: 96.2 acres BUILDING AREA(gross): N/A his} SUMMERY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Singleamily with RP/IH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Convenience Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres cf Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. Et'VIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemem of the Probable Probable More Element of the Probable Probable More Environ nent Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation LandUSh,,reline Use Utilities Animals Transportation Environr rental Health Public Services Energy/Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. PCILICY-RELATED COMMENTS C. CC IDE-RELATED COMMENTS k)O ( Ml we We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where ad iitional information is needed to properly assess this proposal. l!a2a17,6-- 7/qq Signature of Director or Authorized Representative Date DEVAPP Rev 10/93 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIEVING DEPARTMENT: Swv{otulejetekv_. COMMENTS DUE: JUNE 8, 1999 APPLI(:ATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 Ojik APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind ck ' ' c. 4F. Ni.PROJE CT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 41, LOCAL ION: SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension 79 ;,. SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A SUMM,\RY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with R'AH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and' Convenience Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres of Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. ENVIRONMENTAL IMPACT(e.g.Non-Code) COMMENTS Element of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/SI oreline Use Utilities Animal:Transportation Environ nental Health Public Services Energy'Historic./Cultural Natural Resources Preservation rAirport Environment I 10,000 Feet 14,000 Feet B. P')LICY-RELATED COMMENTS C. CODE-RELATED COMMENTS cMbwl>M-e/vv • We hay r reviewed this application with particular attention to those areas in which we have expertise and have Identified areas of probable impact or area: where a iditional i formation is needed to properly assess this proposal. 6A qq Signatui e of Director or Authorized Representative Date DEVAPP Rev.10/9 i- ON SIRE 'DEi c PREVENTION BUREAU City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REND ISRFET REVIEWING DEPARTMENT: Ewe, treu,-hr \ COMMENTS DUE: JUNE 8, 1999 -"( iF 1VEO APPLICATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCAL ION: SE Quadrant of NE 3`a/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A SUMMARY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with R;AH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Convenience Commercial land use with CC Zoning. he revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres of Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. EVVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Sl oreline Use Utilities Animal:Transportation Environ rental Health Public Services i Energy,Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. P:)LICY-RELATED COMMENTS C. C DDE-RELATED COMMENTS We hav?reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area., where a iditional information is needed to properly assess this proposal. zeitt 1/// Signatui a of Director or Authorized Representative Date DEVAPP Rev.10/9 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIE'NING DEPARTMENT: Pkav\ ( ,tt , Ws'fev- COMMENTS DUE: JUNE 8, 1999 APPLI(:ATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 • APPLI(:ANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind pc PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment_ WORK ORDER NO: 78520 1 LOCAl ION: SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres l BUILDING AREA(gross): N/A SUMMARY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Sing4p Family with RVIH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Convenience Commercial land use with CC Zoning. he revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres of Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. EVVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemer t of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/SI oreline Use Utilities Animal;Transportation Environ nental Health Public Services Energy,Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. P)LICY-RELATED COMMENTS C. C'DE-RELATED COMMENTS IVC7 cow4k4fAgt • We hav reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area, where a iditiona information is needed to property assess this proposal. 4/7 Af Si nature of Director or Authorized epresentative Date DEVAPP P Rev.10/9 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIE"VING DEPARTMENT: 654•61-v C-hCVl Aft COMMENTS DUE: JUNE 8, 1999 APPLICATION NO: LUA-99-054,R,CPA,ECF DATE CIRCULATED: JUNE 1, 1999 C,' Op APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind 14.4_ ArrON PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 02 LOCAL ION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension yw, r y, 19g SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A IviSiO,, SUMMARY OF PROPOSAL: Comprehensive Plan Amendment and Rezone of 96 acres from Residential Single Family with RMH Zoning to Residential Options (R-10 Zoning) and Residential Planned Neighborhood (R-14 Zoning) and Convenience Commercial land use with CC Zoning. The revised project is for 20 acres of RPN (R-14 Zoning), 74.2 acres of Residential Options (R-10) Zoning) and .9 acre of Convenience Commercial (CC Zoning). A. E VVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemen of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Si oreline Use Utilities Animal:Transportation Environ nental Health Public Services Energyi Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. P)LICY-RELATED COMMENTS 1't7E C. C)DE-RELATED COMMENTS We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area! where additior{al information is needed to properly assess this proposal. fi/ , c Date "Sig re of irector o uthonzed Representative DEVAPP Rev 10/9 CJ Y O e e 1,E Nrf0 REVISED NOTICE OF APPLICATION A Master Application has bean filed and accepted with the Development Services Division of the City of Renton. The following briefly describes the application and the necessary Public Approvals.This application was revised on May 27,1999. PROJECT NUMBERINAME: LUA-99-054,CPA,ECF,R/LaPlanta Limited Partnership Rezone and Comprehensive Plan Map and Text Amendment(CPA) PROJECT DESCRIPTION: Amend the Land Use Map to change 74.2acres of this property front Residential Single Family with RMH zoning to Residential Oplions(RO)with R-10 zoning,and 20 acres to Residential Planned Neighborhood(RPN)with R-14 zoning,and.9 acres to Convenience Commercial with CC zoning.The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. PROJECT LOCATION: SE Quadrant of NE 3^/NE de and Edmonds Avenue Extension PUBLIC APPROVALS: Planning Commission Public Hearing and Recommendation,City Council Approval Comments on the above application must be submitted in venting to Rebecca Lind,Project Manager,Strategic Planning Division 1055 South Grady Way,Renton,WA 98055,by 5:00 PM on June 14,1999. If you have questions about this proposal,or wish to be made a party of record and receive additional notifcation by mail.contact Ms.Und at(425)430- 6588. Anyone who submits written comments will automatically become a party of record and will be notified of any decision on this project. PLEASE INCLUDE THE PROJECT NUMBER WHEN CALLING FOR PROPER FILE IDENTIFICATION DATE OF APPLICATION: March 31,1999,Revised May 27,1999 NOTICE OF COMPLETE APPLICATION: April 19,1999,Revised June 1,1999 DATE OF NOTICE OF APPLICATION: April 20,1999,Revised June 1,1999 11111 0 ax l: iir a qi; ii.SaMOIlig NOTICEOF CERTIFICATION I, 1.-- i 6 De l,l hereby certify that j copies of the above document were posted by me in 7- conspicuous places on or nearby the described property on \_1i,(t ', ' Signed: ATTEST: Subcribed and sworn before me, a Nortary Public in for the State of - Washington residing in s, za , on the 4 day of xx.c /915 Th cut,A----d>"),-, Kit.-0-# MARILYN KAMCHlcFF COMMISSION EXPIRES 6/29/99 - r cti-gt REVISED NOTICE OF APPLICATION A Master Application has been filed and accepted with the Development Services Division of the City of Renton. The following briefly describes the application and the necessary Public Approvals. This application was revised on May 27,1999. t PROJECT NUMBER/NAME: LUA-99-054,CPA,ECF,R / LaPianta Limited Partnership Rezone and Comprehensive Plan Map and Text Amendment(CPA) PROJECT DESCRIPTION: Amend the Land Use Map to change 74.2acres of this property from Residential Single Family with RMH zoning to Residential Options(RO) with R-10 zoning, and 20 acres to Residential Planned Neighborhood(RPN)with R-14 zoning,and.9 acres to Convenience Commercial with CC zoning. The proposal to change land use policies to allow senior stacked flats within the RPN designation is withdrawn. PROJECT LOCATION: SE Quadrant of NE 3'd/NE 4l"and Edmonds Avenue Extension PUBLIC APPROVALS: Planning Commission Public Hearing and Recommendation,City Council Approval Comments on the above application must be submitted in writing to Rebecca Lind, Project Manager, Strategic Planning Division 1055 South Grady Way, Renton, WA 98055, by 5:00 PM on June 14, 1999. If you have questions about this proposal,or wish to be made a party of record and receive additional notification by mail, contact Ms. Lind at(425)430- 6588. Anyone who submits written comments will automatically become a party of record and will be notified of any decision on this project. PLEASE INCLUDE THE PROJECT NUMBER WHEN CALLING FOR PROPER FILE IDENTIFICATION DATE OF APPLICATION: March 31,1999,Revised May 27,1999 NOTICE OF COMPLETE APPLICATION: April 19,1999,Revised June 1, 1999 DATE OF NOTICE OF APPLICATION: April 20, 1999,Revised June 1, 1999 U\.. I f tUN AS[p N Aulian 99•M-:f\ I'VI( NC IIh SIppli1I k9 RM-I I ;CA i I p e c)5. l / R-10 R-10; 1 \ nJA RM-1 x R 8 IL(P) RMH g U I 1 5 R-8 RMH S i RC i • RC Sw St_' K-8_ OR `. tf', : R46! B RC(P) l ill;'-'1 I R-8 1 m•u TUNwW VI ..... F5M 16 TIJN RSE W VS NOTICEOF i•0 s9• Z. d. se' Sound Energy&Elec Puget T&E INVESTMENT INC ATLANTIC RICHFIELD COMPANY PO Box 90868 353 Vuemont Pl Ne PO Box 512485 Bellevue,WA 98009 Renton,WA 98056 Los Angeles, CA 90051 KING COUNTY Lp LaPianta KING COUNTY 500 4Th Ave PO Box 88050 500 K C Admin Bldg#A Seattle,WA 98104 Tukwila,WA 98138 Seattle, WA 98104 NOT AVAILABLE FROM COUNTY MT OLIVET CEMETERY Keith&Annette Demps Sr. 6205 24Th St Ne PO Box 547 2308 Ne 24Th St Tacoma,WA 98422 Renton,WA 98057 Renton,WA 98056 Lp LaPianta ANMAR CO RENTON THIRD AVE PROP LLC PO Box 8805 9125 I OTh Ave S PO Box 814 Tukwila,W 98 Seattle,WA 98108 Zillah, WA 98953 Sound Ener_ : Elec Puget ANMAR C RAMAC INC PO Box 908,:9125 10 ve S 20919 Se 34Th St Bellevue, A 9:$09 Seattle,W 8108 Issaquah,WA 98029 Seung Sik&Eunsil Paik Seung Si & unsil Paik Phyllis Lame 2439 Se Maple Valley Hwy 2439 Se le Valley Hwy 2505 Maple Valley Hwy Renton,WA 98055 Renton, W 8055 Renton, WA 98058 KING CO Y KING TY KING O Y 500 4Th A 500 4 ve 500 4Th v Seattle, 04 Seattle,WA 98104 Seattle, W 98104 KING CO T Portfolio Lp Essex STATE OF WASHINGTON 500 4Th Av 777 S California Ave 2631 Ne 4Th St Seattle, WA 104 Palo Alto,CA 94304 Renton, WA 98056 Housing Authority Renton Lp La 'an 970 Harrington Ave Ne PO Box 050 Renton,WA 98056 Tukwil , 98138 cs =CITY OF RENTON il Planning/Building/Public Works Department Jesse Tanner,Mayor Gregg Zimmerman P.E.,Administrator June 1, 1999 Ms. Ann Nichols La Pianta Limited Partnership PO Box 88028 Tukwila, WA 98138 SUBJECT: La Pianta Rezone (R) and Comprehensive Plan Amendment(CPA) Project No. LUA-99-054,CPA,R,ECF Dear Ms. Nichols: The Development Planning Section of the City of Renton has determined that the subject application is complete according to submittal requirements and, therefore, is accepted for review. It is tentatively scheduled for consideration by the Environmental Review Committee on June 15, 1999. Prior to that review, you will be notified if any additional information is required to continue processing your application. Please contact me, at (425) 430-6588, if you have any questions. Sincerely, Rebecca Lind Project Manager ACCEPT 1055 South Grady Way-Renton,Washington 98055 CITY OF RENTO[ 1=L PME V" E .D V t PROPERTY OWNER(S PROJECT:INFORMATION Note If there s more than one fepal owner,please attach an additional notaFized Masten Applicationfo.each:owne. .'..... : ,: PROJECT OR DEVELOPMENT NAME: NAME: La Pianta Limited Partnership La Pianta Comprehensive Plan Mc P Amendments and Rezone (revised 5/27/99) PROPERTY/PROJECT ADDRESS(S)/LOCATION: ADDRESS: P.O. Box 88028 South side of NE 3rd/NE 4th Street and east of both the Mt. Olivet Cemetery and the proposed La Colina subdivision, Renton, WA CITY: Tukwila ZIP: 98138 KING COUNTY ASSESSOR'S ACCOUNT NUMBER(S): 162305-9006-05 172305-9171-03 162305-9007-04 162305-9009-02 TELEPHONE NUMBER: (206) 575-2000 162305-9061-07 162305-9010-09 EXISTING LAND USE(S): VACANT APPLICANT ( f.other than owner) NAME: SAME AS OWNER PROPOSED Familys(attached and detached); Multi Family (6 units per building max.)and Convenience Commercial COMPANY(if applicable): EXISTING COMPREHENSIVE PLAN MAP DESIGNATION: Residential Single Family (RS) and Residential Multi-Family Infill (RM-I) ADDRESS: PROPOSED COMPREHENSIVE PLAN MAP DESIGNATION (if applicable) Residential Options (R0) ; Residential Planni 1 Neighborhood (RPN) ; and Convenience CITY: ZIP: E FIViel4: (CC) Residential Manufactured Homes (RMH) and TELEPHONE NUMBER: Residential Multi-Family Infill (RM-I) PROPOSED ZONING (if applicable): Residential-10 DU/AC (R-10) ; CONTACT PERSON Residential-14 DU/AC (R-14) ; and s nCE° 'antt in OFT EAc61 :l (CC) NAME: Ann Nichols 96.2 acres +:/- COMPANY (if applicable): PROJECT VALUE: La Pianta Limited Partnership N/A ADDRESS: IS THE SITE LOCATED IN THE AQUIFER PROTECTION AREA? P.O. Box 88028 Yes, partially in APA Zone 1 and partially in APA Zone 2 CITY: Tukwila ZIP: 98138 IS THE SITE LOCATED IN ANY OTHER TYPE OF ENVIRONMENTALLY SENSITIVE AREA? TELEPHONE NUMBER: Not to Applicant's knowledge 206) 575-2000 LEGAL:DE RIPTI;ON OF PROPERTY (Attach orate sheet if nec'essaryi PARCELS 1 THROUGH 9 AND 10 OF CITY OF RENTON LOT LINE REVISION FILE NUMBER LUA-95-200-LLA, AS RECORDED IN BOOK 108 OF SURVEYS AT PAGES 276, 276A AND 276B, UNDER KING COUNTY RECORDING NUMBER 9604239004. TYPE Of=.APPLICATION & FEES Check. all appl(cat(ontypes.that apply City staffw(II determine tees ANNEXATION S SUBDIVISION: COMP. PLAN AMENDMENT REZONE LOT LINE ADJUSTMENT SPECIAL PERMIT SHORT PLAT TEMPORARY PERMIT TENTATIVE PLAT CONDITIONAL USE PERMIT PRELIMINARY PLAT SITE PLAN APPROVAL FINAL PLAT GRADE & FILL PERMIT NO. CU. YDS: PLANNED UNIT DEVELOPMENT: VARIANCE ' FROM SECTION:PRELIMINARY WAIVER FINAL WETLAND PERMIT S ROUTINE VEGETATION MOBILE HOME PARKS: S MANAGEMENT PERMIT BINDING SITE PLAN SHORELINE REVIEWS: SUBSTANTIAL DEVELOPMENT $ CONDITIONAL USE VARIANCE EXEMPTION No Charge ENVIRONMENTAL REVIEW S REVISION S AFFIDAVITOF ':OWNERSHIP . I, (Print Name) M.A. Segale declare that I am (please check one) _the owner of the property involved in this application, X the authorized representative to act for the property owner (please attach proof of authorization), and that the foregoing statements sg veers herein contained and the information herewith submitted are in all respects true and correct to the best of my knowledge and bel`yL' A. p`NA11iN LA PIANTA LIMITED PARTNERSHIP, a S °.•••••.• < /1 Washington limited partnership 4g1 G N E •9 'tl ATTEST: Subscribed and sworn to befo. me,.p#etar ublic;fip 9nd f r the St f residing air 214: U'AR , la • By: Metro Land Development, Inc., a j cn the p dap fart S4hirigtcncmaticn, its Cameral Partrer y ,9 P U 6 1. i .1 Air By: M.A. Segale, President Si. re of Notar ubi; ) I tlUFWAS;=` This;;section to be>completed.by Crty;<Staf.') City File Number . A AAD ;BSP :;CAP=S ..CAP U CPA CU A CU H ECF .LLA MHP ..FP<UD ..FP PPR :RVMP. :SA A. :SA H :SHPL-A :SHPL H >SP ..>SM SME TP:;V A ..V B V.H W TOTAL FEES S_ TOTAL POSTAGE PROVIDED. $ MASTERAP.DOC REVISED 8/97 CITY OF RENTON RECEIVED MAY 2 7 1999 BUILDINCi OWISION Project Narrative Justification for Comprehensive Plan Amendment, Rezone Project Name: La Pianta Comprehensive Plan Amendments and Rezone Project Location: South side of NE 3` d/NE 4th Street east of Mt. Olivet Cemetery, Renton, WA Current Use: Vacant Land (mined out gravel pit) Current Zoning: RMH — Residential Manufactured Homes and Residential Multi-Family Infill (RM-I) Proposed Zoning: R-14, R-10 and CC Proposed Use:Mixed Use Residential Development with a small convenience commercial use. Proposed by: La Pianta Limited Partnership ("La Pianta") 1. Requested Change to Comprehensive Plan and/or Zoning Map La Pianta hereby requests comprehensive plan land use map amendments and corresponding rezoning on several adjacent parcels of its land located on the south side of NE 3' d/NE 4th Streets at the intersection with Edmonds Avenue NE in Renton, WA. La Pianta is making this formal application, along with all supporting and requested documents listed by the City of Renton in its guide to Comprehensive Plan Amendments. Nearly all of the subject property is currently zoned RMH — Residential Manufactured Homes (RMH), a zoning classification that does not allow development of a mixed use community. La Pianta proposes to change that portion of the site's zoning so that a portion would be R-14 and toe balance would be R-10, similar to the land use designation for some of the properties surrounding the subject property. A small portion of the site (about 0.92 acres at the site's northwest corner) is currently designated and zoned Residential Multi- Family Infill (RM-I). La Pianta proposes a Convenience Commercial (CC) designation and zoning for that portion of the property. As part of the proposal, La Pianta stipulates to the following four site-specific restrictions (the "Proposed Site-Specific Restrictions"): 1) Permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the number and type of residential units in combination with the building square footage of convenience commercial development would not Proj-Nar-v2.Fl.doc, 5/27/99, page 1 be expected to generate more than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers (ITE) Manual; 2) Permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the total impervious surface coverage due to the combined residential and convenience commercial development would not be expected to exceed a total of 45.04 acres; 3) The overall number of residential units of any type could not exceed 490 units; and 4) The overall number of flats (which would only be constructed in the R-14-zoned portion of the site) could not exceed 78 units and the number of flats in any such building could not exceed 6 units. La Pianta contemplates ultimate development of a mixed use community on the subject property with four villages that would feature townhouses/flats, alley- loaded and traditional townhouses, as well as alley-loaded and traditional single family homes. 2. Size and Location of Site The subject property is located on the south side of NE 3` d/NE 4th Streets, east of Mt. Olivet Cemetery, west of the King County Shops and north of the Maple Valley Highway in Renton. The subject property consists of six contiguous parcels owned by La Pianta totaling about 95 or 96 acres in size. The south edge of these parcels has an irregular shape that follows the top of slope above the Maple Valley Highway. 3. Current Use of Site and Any Existing Improvements The site is currently vacant after having been previously used as a gravel mine. Improvements for the southerly extension of Edmonds Avenue into the property have recently been constructed. Significant grading of portions of the site has occurred as part of a previously-approved manufactured housing project (Cedar Crest) and in relation to the City's sewer interceptor line that crosses the property. There are currently no structures on the site. Proj-Nar-v2.Fl.doc, 5/27/99, page 2 4. Special Site Features Special site features include the site's location, size and topography. The location is a prominent one in the Renton Highlands and would be attractive to potential homeowners with its easy access to downtown Renton and the nearby commercial uses along NE 4th Street. The site's relatively large size would allow for the development of a quality mixed use neighborhood with single family homes, townhouses, a limited number of flats, a small convenience commercial facility and parks and open space, both active and passive. The topography would allow a new neighborhood to be built below NE 3` d/NE 4th Streets with little visual impact. Further, the site's topography and southward orientation provides opportunities for substantial southerly views. 5. Location of Existing Structures This site is currently vacant with no existing structures. 6. Special responses to the following Decision Criteria: 1. The CPA/Rezone bears a substantial relation to the public health, safety or welfare. The requested Comprehensive Plan Amendments and rezone, if granted, would allow for the provision of a wide variety of housing to address the needs of area residents, would provide substantial opportunities for home ownership, and would increase the City's tax base. 2. The CPA/Rezone addresses changing circumstances or the needs of the City as a Whole. The City of Renton as a whole is experiencing an increase in demand for both residential real estate and commercial space as a result of a strong local employment base. This proposal will allow for a variety of housing opportunities to meet the varied needs of the housing market and provide housing opportunities for employees of local businesses. The small convenience commercial portion of the proposal will readily serve future development on the proposed site as well as the La Colina subdivision. Proj-Nar-v2.Fl.doc, 5/27/99, page 3 3. The CPA/Rezone is compatible with the provisions of the Comprehensive Plan or other policies or goals of the City The requested CPA's and rezone are compatible with the Comprehensive Plan as it furthers the goals and policies of the plan to increase the variety of housing and channel growth into the City's urban area. Please refer to the following section addressing the policies. This location is ideal for a mixed use community in view of it's easy access to downtown Renton and the NE 3` d/NE 4th Street corridor. 4. The CPA/Rezone is compatible with and not materially detrimental to adjacent Land uses and surrounding neighborhoods. See answer#3 above. Once the subject property is developed, the adjacent landowners and residents will no longer have to look at the undeveloped property in its current state and the neighborhood will be improved, both aesthetically and economically, as a result of the proposed project. The mixed use proposal, especially with the topography, is very compatible with all the surrounding uses including the proposed plat of La Colina to the west. 5. The CPA/Rezone will not result in development which will adversely impact community facilities, including but not limited to utilities, transportation, parks or schools The portion of the site that currently has an RS Comprehensive Plan land use designation would allow for development under theR-8 zone (8 dwellings per acre or about 413 single-family lots). The 0.92-acre portion of the site that currently has an RM-I Comprehensive Plan land use designation would allow for development under the RM-I zone (20 dwellings per acre or about 18 multi-family units). La Pianta's proposal calls for a slight increase in density, yet, with the variety of housing types contemplated, including conventional single-family detached homes, attached townhouse homes and flats, the impacts on utilities, transportation, parks, or schools will be very similar to the impacts of R-8 development. No adverse impacts on such community facilities are expected. 6. The subject property is suitable for development in general conformance with zoning standards under the proposed zoning classification. Proj-Nar-v2.Fl.doc, 5/27/99, page 4 With the site's previous grading and the installation of storm drainage facilities, the site portion of the site that currently has an RS Comprehensive Plan land use designation is very well-suited to development under the proposed R-10 and R-14 zoning classifications. The R-10 classification allows for both attached and detached housing. The R-14 classification allows for the envisioned attached homes and a limited number of stacked flats. The small convenience commercial area will serve both the subject property and the nearby La Colina subdivision. Development densities in both the R-10 and R-14 zones will most likely be near the minimum densities called for in the City's code. The proposed Comprehensive Plan Amendments to Residential Planned Neighborhood (RPN) and Residential Options (RO) is consistent with the City's goals and policies, as noted in the following: General Residential Policies: LU-11 The proposal will allow development of vacant land in environmentally suitable land on the hills and plateaus surrounding downtown Renton. Residential-Types LU-15 The proposal will allow a mix of housing types including large lot and small lot single family development, and residential mixed use development. LU-16.1 The proposal will allow a mix of single family and small scale multi-family housing types designed to look like single family development with ground related entries, i.e. duplex, triplex, and fourplex. Residential Options and Residential Planned Neighborhood General Policies LU-41 The proposal will provide opportunity for small-lot single family detached homes and townhouses that meet the R-10 density standards. LU-42 The proposal will provide opportunity for a range of lot sizes. LU-43 The applicant envisions a central point at the entry to the contemplated new neighborhood on this site with passive open space facilities and a small neighborhood commercial use. Proj-Nar-v2.Fl.doc, 5/27/99, page 5 LU-45 The site is conducive to a flexible grid street system generally of the type that the City has previously approved for the earlier manufactured housing project proposal. Residential Options Policies LU-50 The proposal meets the criteria for the Residential Option Designation through the following: a) the adjacent parcel to the northeast is currently zoned R- 10, b) the development proposal that La Pianta envisions for the proposed R-10 portion of the site would involve a mix of traditional and alley-loaded single family detached homes (similar in density to the manufactured housing project previously approved) and attached townhomes in duplex, triplex and fourplex configurations, c) the subject parcels are currently vacant, d) few new roads or major utility upgrades will be required since a City sanitary sewer interceptor has already been constructed through the site and a southerly extension of Edmonds Avenue NE has already been installed, and e) the site is adjacent to a City mapped Institutional Center. LU-51 and LU-54 The envisioned development on the proposed R-10 portion of the site would involve a net density between 7 to 8 homes per acre, ranging from attached townhomes to small alley-loaded homes to larger executive lots. Residential Planned Neighborhood Policies LU-57 The proposed RPN portion of the site meets the criteria for RPN designation by a) being located close to NE 3` d/4` h Street, a major arterial, b) being adjacent to the City mapped Institutional Center and the employment corridor along NE 4th Street, c) being 20 acres in size, d) being buffered from other single family neighborhoods (the site will be separated from the La Colina subdivision to the west by power line easements) and is compatible with the other surrounding uses due to the site's topography (which is generally well below that of adjacent areas) and e) by having achievable potential for development within the density and unit type range called for in the Comprehensive Plan and Zoning Code. LU-58 The envisioned development within the proposed R-14 portion of the site would include attached single family residences to senior oriented (age restricted) townhouses and flats. Proj-Nar-v2.Fl.doc, 5/27/99, page 6 ENVIRONMENTAL CHECKLIST INTRODUCTION Purpose of Checklist: The State Environmental Policy Act (SEPA), Chapter 43.21C RCW, requires all governmental agencies to consider the environmental impacts of a proposal before making decisions. An environmental impact statement EIS) must be prepared for all proposals with probable significant adverse impacts on the quality of the environment. The purpose of this checklist is to provide information to help you and the agency identify impacts from your proposal (and to reduce or avoid impacts from the proposal, if it can be done) and to help the agency decide whether an EIS is required. Instructions for Applicants: This environmental checklist asks you to describe some basic information about your proposal. Governmental agencies use this checklist to determine whether the environmental impacts of your proposal are significant, requiring preparation of an EIS. Answer the questions briefly, with the most precise information known, or give the best description you can. You must answer each question accurately and carefully, to the best of your knowledge. In most cases, you should be able to answer the questions from your own observations or project plans without the need to hire experts. If you really do not know the answer, or if a question does not apply to your proposal, write "do not know" or "does not apply". Complete answers to the questions now may avoid unnecessary delays later. Some questions ask about governmental regulations, such as zoning, shoreline, and landmark designations. Answer these questions if you can. If you have problems, the governmental agencies can assist you. The checklist questions apply to all parts of your proposal, even if you plan to do them over a period of time or on different parcels of land. Attach any additional information that will help describe your proposal or its environmental effects. The agency to which you submit this checklist may ask you to explain your answers or provide additional information reasonably related to determining if there may be significant adverse impact. Use of checklist for nonproject proposals: Complete this checklist for nonproject proposals, even though questions may be answered "does not apply". IN ADDITION, complete the SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS (part D). For nonproject actions (actions involving decisions on policies, plans and programs), the references in the checklist to the word "project", "applicant", and "property or site" should be read as "proposal," proposer", and "affected geographic area," respectively. CITY OF RENTON RECEIVED MAY 2 7 1999 BUILDING DIVISION ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 1 A. BACKGROUND 1. Name of proposed project, if applicable: La Pianta Comprehensive Plan Amendments and Rezone (a non project action) 2. Name of applicant: La Pianta Limited Partnership 3. Address and phone number of applicant and contact person: Applicant: Contact Person: Attn: Ann Nichols Craig J. Krueger c/o Segale Business Park C/O Dodds Engineers, Inc. (DEI) P 0 Box 88050 4205 - 148th Ave. N.E., Suite 200 Tukwila, WA 98138 Bellevue, WA 98007 206) 575-2000 425) 885-7877 4. Date checklist prepared: May 27, 1999 5. Agency requesting checklist: City of Renton Department of Planning/Building/Public Works 6. Proposed timing or schedule (including phasing, if applicable): The proposed Comprehensive Plan Amendments and Rezone are anticipated to be processed by the City by Fall 1999. Development is anticipated to start in the Spring of 2000 dependant on the approval of the CPA and rezone application as well as subsequent site plan and preliminary plat applications. 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. Development of the subject property consistent with the proposed Comprehensive Plan Amendments and Rezone is contemplated in future years but is not part of this proposed non project action. 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. The City of Renton issued a Draft Environmental Impact Statement for the City of Renton Comprehensive Plan's Land Use Element (dated January 16, 1992) and a two-volume Final Environmental Impact Statement for the City of Renton Comprehensive Plan's Land Use Element dated February 1, 1993). Note that Volume 2 of that FEIS includes special "McMahon Property" studies involving analyses of that property under three different Comprehensive Plan Land Use Map scenarios: (1) Office, (2) "Single Family/4 Mix" (according to Renton's Rebecca Lind, Single ENV-CHECKLIST-2.F1.doc;05/27/99; Page: 2 Family/4 Mix was a precursor to what is currently the Residential Options (RO) Land Use Map designation), and (3) Single Family/Education-Institution Center. (The subject property is a portion of the McMahon Property special study area.) Attached hereto is a set of copies of the Land Use Study Areas Vehicle Trip Generation Report (including "Appendix A—Study Area Land Use and Estimated Trip Generation" thereto). 9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. No. 10. List any government approvals or permits that will be needed for your proposal, if known. City Council approval of the proposed Comprehensive Plan Amendments and Rezone. 11. Give a brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) The originally-submitted application (March 31, 1999) requested that (a) approximately 42.6 acres of the site be given a Residential Options (RO) Land Use Map designation and corresponding R-10 zoning and (b) approximately 53.6 acres of the site be given a Residential Planned Neighborhood (RPN) Land Use Map designation and corresponding R-14 zoning. In contrast, the amended application (May 27, 1999) requests that, subject to particular site-specific development restrictions to be set forth in a Development Agreement between the City and the property owner and recorded to run with the land, (a) approximately 74.2 acres of the site be given a Residential Options RO) Land Use Map designation and corresponding R-10 zoning (those 74.2 acres are currently designated Residential Single Family and zoned Residential Manufactured Home (RMH)), (b) 20 acres of the site (the minimum size permitted under Comprehensive Plan Policy LU-57) be given a Residential Planned Neighborhood (RPN) Land Use Map designation and corresponding R-14 zoning (those 20 acres are also currently designated Residential Single Family and zoned RMH), and c) the northwesterly-most 0.92-acre portion of the site (which is currently designated and zoned Residential Multi-Family Infill (RM-I)) be designated and zoned Convenience Commercial (CC). The locations of the requested Land Use Map designations and zoning classifications are set forth on the accompanying amended Property Map. The site-specific development restrictions that the proponent has proposed (the "Proposed Site- Specific Restrictions") are the following: 1) Permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the number and type of residential units in combination with the building square footage of convenience commercial development would not be expected to generate more than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers (ITE) Manual; 2) Permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the total impervious surface coverage ENV-CHECKLIST-2.F 1.doc; 05/27/99; Page: 3 due to the combined residential and convenience commercial development would not be expected to exceed a total of 45.04 acres; 3) The overall number of residential units of any type could not exceed 490 units; and 4) The overall number offlats (which would only be constructed in the R-14-zoned portion of the site) could not exceed 78 units and the number offlats in any such building could not exceed 6 units. 12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. The site is located north of Maple Valley Highway, south of NE 3rd/NE 4th Street, east of Mt. Olivet cemetery and west of the King County shops in the City of Renton. A property map is attached hereto and incorporated by reference. 13. Does the proposal lie with an area designated on the City's Comprehensive Land Use Policy Plan map as environmentally sensitive? Yes, the proposed project is partially in Aquifer Protection Area Zone 1 and partially in Aquifer Protection Zone 2. The RC-zoned area south of the site is designated Greenbelt. B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous other The portion of the site where most of the future development on the site is expected is gently sloping, while the perimeter of the site contains steeper slopes. b. What is the steepest slope on the site (approximate percent slope)? The steepest slope is ± 67%. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. Sand and gravel, no agricultural soils. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. No. Note that the stability of the southern slope is addressed in three detailed geotechnical reports prepared in regard to the site by GeoEngineers dated March 7, 1994, October 24, 1994, ENV-CHECKLIST-2.F 1.doc;05/27/99; Page:4 and April 6, 1995 in conjunction with the previously-approved (and still vested) "Cedar Crest Manufactured Home Park", copies of which are included in the accompanying February, 11, 1999 "Storm Drainage Report" binder for Cedar Crest Phases I, II, III and IV prepared by Triad Associates. Note further that, on page 7 of the October 24, 1994 GeoEngineers report, the report indicates that "[i]nfiltrated ground water in this area would . . .flow to the northwest . . . and that "[t]his is also supported by the lack of evidence of significant ground water seepage occurring on [the portion of the bluff being analyzed in the report]". e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. None proposed at this time. Application is for CPA and rezone only. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. A storm water retention/recharge system has already been designed for the site, approved by the City of Renton and constructed in relation to the Cedar Crest Manufactured Home Park. Modifications may or may not have to be made to that system in order to accommodate ultimate development subsequent to City Council approval of the requested CPA and rezone requests. While some erosion may take place during such ultimate development, because of(a) the nature of the site's topography and (b) the erosion control measures that the City will require, substantial quantities of sediment-laden water are not anticipated to leave the site. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? In view of Proposed Site-Specific Restrictions 2's limitation of total impervious surface coverage of the approximately 95.1-acre site to 45.04 acres, not more than 47.3 percent of the site would be covered with impervious surfaces. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: N/A (They will be developed in the future in regard to a project-specific proposal.) 2. Air a. What types of emissions to the air would result from the proposal (i.e., dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. Unknown at this time. Application is for CPA and rezone only. b. Are there any off-site sources of emissions or odor that may affect your proposal? If so, generally describe. No. c. Proposed measures to reduce or control emissions or other impacts to air, if any: None proposed at this time. 3. Water ENV-CHECKLIST-2.F1.doc; 05/27/99; Page: 5 a. Surface: 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. Storm water retention and silt control structures and other man-made facilities only. 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. Not applicable. 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. Not applicable. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. Not applicable. 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. No. 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. No. b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities if known. N/A 2) Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage: industrial, containing the following chemicals....; agricultural; etc.). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. N/A c. Water Runoff(including storm water): ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 6 1) Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. A stormwater retention/recharge system has already been designed for the site, approved by the City of Renton and constructed in relation to the Cedar Crest Manufactured Home Park. A January 11, 1988 hydrogeologic-geotechnical study by Golder Associates plus portions of the above-referenced geotechnical reports by GeoEngineers bear upon that system as well as does a "Level I Drainage Study and Preliminary Storm Drainage Calculations" by Barghausen Consulting Engineers, Inc. dated October 12, 1994 (as revised November 4, 1994), all of which are included in the accompanying February 11, 1999 "Storm Drainage Report" binder for Cedar Crest Phases I, II, III and IV prepared by Triad Associates. Modifications may or may not have to be made to that system in order to accommodate ultimate development subsequent to City Council approval of the requested CPA and rezone requests. 2) Could waste materials enter ground or surface waters? If so, generally describe. N/A d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: None proposed at this time. Storm ponds have already been installed—see above. 4. Plants a. Check or underline types of vegetation found on the site: X deciduous tree: alder, maple, aspen, other: X evergreen tree: firr, cedar, pine, other: X shrubs grass pasture wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other water plants: water lily, eelgrass, milfoil, other: other types of vegetation: b. What kind and amount of vegetation will be removed or altered? Trees and shrubs have been removed as part of the clearing and grading of the site associated with the previously approved manufactured housing project and previously conducted gravel mining of the site. c. List threatened or endangered species known to be on or near the site. None. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: N/A (Note: The sloped areas along the perimeter of the site affected by grading have been hydroseeded.). 5. Animals ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 7 a. Underline any birds and animals which have been observed on or near the site or are known to be on or near the site: birds: hawk, heron, eagle, songbirds, other: crows and miscellaneous small birds mammals: deer, bear, elk, beaver, other: squirrels, chipmunks, raccoons fish: bass, salmon, trout, herring, shellfish, other: None b. List any threatened or endangered species known to be on or near the site. None. c. Is the site part of a migration route? If so, explain. Unknown. d. Proposed measures to preserve or enhance wildlife, if any: N/A 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Unknown at this time. Application is for CPA and rezone only. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No. c. What kinds of energy conservation features are included in the plans of this proposal: List other proposed measures to reduce or control energy impacts, if any: None. Application is for CPA and rezone only. 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. No. 1) Describe special emergency services that might be required. None ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 8 2) Proposed measures to reduce or control environmental health hazards, if any: None. b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? None. 2) What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. Unknown at this time. Application is for CPA and rezone only. 3) Proposed measures to reduce or control noise impacts, if any: N/A 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? The site is vacant, having been recently graded for the Cedar Crest manufactured housing project. The current use of the adjacent properties is as follows; Cemetery, King County Transfer station and shops, manufactured home park and multi family residential. b. Has the site been used for agriculture? If so, describe. No. ENV-CHECKLIST-2.F1.doc;05/27/99; Page: 9 c. Describe any structures on the site. None. d. Will any structures be demolished? If so, what? None. e. What is the current zoning classification of the site? The current zoning is RMH—Residential Manufactured Homes. f. What is the current comprehensive plan designation of the site? RS"—Residential Single family. g. If applicable, what is the current shoreline master program designation of the site? Not applicable. h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. Yes, the proposed project is partially in Aquifer Protection Area Zone 1 and partially in Aquifer Protection Area Zone 2. (The RC-zoned portion south of the site is designated Greenbelt.) i. Approximately how many people would reside or work in the completed project? Unknown at this time. Application is for CPA and rezone only. However, in view of Proposed Site-Specific Restriction 3, the overall number of residential units of any type on the site could not exceed 490 units and a 0.92-acre convenience commercial development could be constructed. j. Approximately how many people would the completed project displace? None. k. Proposed measures to avoid or reduce displacement impacts, if any: Not applicable. I. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: Consummation of a Development Agreement between the City and the property owner to embody the Proposed Site-Specific Restrictions. 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low-income housing. Approximately 460 residential units would probably be constructed, with a maximum possible of 490 units. (The accompanying sheet entitled "La Pianta's Planned Residential Development ENV-CHECKLIST-2.F1.doc;05/27/99; Page: 10 Distribution as of 5/27/99"provides a breakdown of the 460 units that the proponent is currently contemplating in four villages. The locations of the villages are generally depicted on the accompanying Property Map.) The units would be a mix of high and middle-income housing. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low-income housing. None. c. Proposed measures to reduce or control housing impacts, if any: Not applicable. 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? Unknown at this time. Application is for CPA and rezone only. b. What views in the immediate vicinity would be altered or obstructed? None. c. Proposed measures to reduce or control aesthetic impacts, if any: None required at this time. 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur. Unknown at this time. Application is for CPA and rezone only. b. Could light or glare from the finished project be a safety hazard or interfere with views? N/A. c. What existing off-site sources of light or glare may affect your proposal? None. d. Proposed measures to reduce or control light and glare impacts, if any: N/A. 12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 11 Liberty Park, Cedar River Park, Windsor Hill Park and the Maplewood golf course are all arc located within 1 mile of the project. b. Would the proposed project displace any existing recreational uses? If so, describe. No. c. Proposed measures to reduce or control impacts on recreation, including recreational opportunities to be provided by the project or applicant, if any? Several onsite parks are contemplated. (See the accompanying Property Pap.) City of Renton parks impact fees would also be paid. 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe. No. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. None. c. Proposed measures to reduce or control impacts, if any: Not applicable. 14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any. Primary access to the site would be provided by the southward extension of Edmonds Avenue NE from NE 3'd/NE 4`h Street, which extension has recently been constructed. There is an existing traffic signal at the intersection of NE 3rd/NE 4`h Street and Edmonds Avenue NE. b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? Yes, there is public transit service on NE 3'd/NE 4th Street. The nearest bus stop is 100 feet from the intersection of NE 3rd/NE 4th Street and Edmonds Avenue NE. c. How many parking spaces would the completed project have? How many would the project eliminate? The number ofparking spaces that a completed development of the site would have is unknown at this time. No parking spaces would be eliminated. (Application is for CPA and rezone only.) ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 12 d. Will the proposal require any new roads or streets, or improvements to existing roads or t 'streets, not including driveways? If so, generally describe (indicate whether public or private). Unknown at this time. Application is for CPA and rezone only. (Internal streets will be required for development of the site, most or all of which will be public streets.) e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. No. f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. In view of Proposed Site-Specific Restriction 1, permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the number and type of residential units in combination with the building square footage of convenience commercial development would not be expected to generate more than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers (ITE) Manual. That is the number of trips that would be equivalent to development of 413 conventional, detached single- family residential lots (in the portion of the site currently designated RS) and 18 multi family units (in the portion of the site currently designated RM-I)—see the accompanying Trip Generation Table prepared by the traffic analysis consulting firm David I. Hamlin & Associates and the accompanying May 27, 1999 letter from attorney David L. Halinen (especially pages 4 and 5). Note in the attached copy of the Land Use Study Areas Vehicle Trip Generation Report's Appendix A (from Volume 2 of the Final Environmental Impact Statement for the City of Renton Comprehensive Plan's Land Use Element, dated February 1, 1993) that extensive trip generation was anticipated from the subject property as part of the McMahon Property special study area. The least intensive of the three different Comprehensive Plan Land Use Map scenarios considered for that special study area was "Single Family/4 Mix" (which, according to Renton's Rebecca Lind, was a precursor to what is currently the Residential Options (RO) Land Use Map designation). With Proposed Site-Specific Restriction 1, the traffic generated by the subject property will certainly not exceed the levels anticipated by that FEIS for the subject property. (It will probably be less.) g. Proposed measures to reduce or control transportation impacts, if any: In conjunction with development applications for the site, a traffic analysis will be prepared to examine the operation of the NE 3'd/4`h-Edmonds Avenue intersection in regard to the trip generation estimated for the ultimate development of the site that is actually proposed in order to see if any further intersection improvements are warranted. Also, City of Renton traffic impact fees would be paid in conjunction with actual development of the subject property.Unknown at this time. Application is for CPA and rezone only. 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection,police protection,health care, schools, other)? If so, generally describe. ENV-CHECKLIST-2.Fl.doc;05/27/99; Page: 13 Application is for CPA and rezone only. Ultimate development of the site pursuant to approval of the request wold result in an increased need for public services. This has already been contemplated in the Draft and Final Environmental Impact Statements for the City of Renton Comprehensive Plan's Land Use Element (circa 1992 and 1993). b. Proposed measures to reduce or control direct impacts on public services, if any. See the Draft and Final Environmental Impact Statements for the City of Renton Comprehensive Plan's Land Use Element (circa 1992 and 1993). 16. Utilities a. Underline utilities currently available at the site: electricity, natural gas, water refuse service, telephone, sanitary sewer, septic system, other. All utilities are available to the site through a proper extension of services. Extension of services will be the developers'responsibility at the time of ultimate development. b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. Electricity will be provided by Puget Sound Energy Natural Gas will be provided by Puget Sound Energy Water Service will be provided by the City of Renton Sanitary Sewer will be provided by the City of Renton Telephone Service will be provided by US West C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying on them to make its decision. i Signature: 41 ?/ Date Submitted: May 27, 1999 Craig eger D. SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS Do not use this sheet for project actions). Non-project actions are those that do not include a specific project. A non-project action may be a rezone, annexation, or amendments to ordinances. For nonproject actions, the references in the checklist to the words "project," "applicant," and property or site" should be read as "proposal," "proposer," and "affected geographic area," respectively. ENV-CHECKLIST-2.F I.doc; 05/27/99; Page: 14 Ir Because these questions are very general, it may be helpful to read them in conjunction with the list of the elements of the environment. When answering these questions, be aware of the extent of the proposal, or the types of activities likely to result from the proposal that would affect the item at a greater intensity or at a faster rate than if the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposal be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? The proposed Comprehensive Plan designations and zoning are very similar in intensity of use to the existing Comprehensive Plan designations and will not significantly increase any discharge to water, emissions to air or production of noise. Uses permitted under the proposed categories will not produce, store or release toxic or hazardous substances. Proposed measures to avoid or reduce such increases are: None proposed since Comprehensive Plan Amendments and Rezone will ultimately result in similar uses to those previously studied and approved by the City for the subject property. 2. How would the proposal be likely to affect plants, animals, fish, or marine life? The site has already been mined and graded and storm drainage/water quality facilities have already been installed. The proposed CPA and rezone will not further affect plants, animals or fish. Proposed measures to protect or conserve plants, animals, fish, or marine life are: When development of the site ultimately occurs pursuant to the proposed zoning, erosion control, water quality and detention facilities will be required per City codes. 3. How would the proposal be likely to deplete energy or natural resources? Future development of the site pursuant to the proposed zoning will have approximately the same impact on energy and natural resources as allowed under the current Comprehensive Plan designation and zoning category. Proposed measures to protect or conserve energy and natural resources are: None required beyond normal City codes. 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated or eligible or under study) for governmental protection; such as parks, wilderness,wild and scenic rivers, threatened or endangered species habitat, historic or cultural sites, wetlands, floodplains, or prime farmlands? There are no such environmentally sensitive areas on the site at this time. Proposed measures to protect such resources or to avoid or reduce impacts are: None required or proposed. ENV-CHECKLIST-2.F 1.doc;05/27/99; Page: 15 f. . 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? The proposed Comprehensive Plan designations and proposed zones are very similar to the existing ones. No significant affect upon land and shoreline use is anticipated. Proposed measures to avoid or reduce shoreline and land use impacts are: The site-specific development restrictions that the proponent has proposed(see above). 6. How would the proposal be likely to increase demands on transportation or public services and utilities? The proposal will be very similar in scale to that envisioned by the City in adopting the current Comprehensive Plan and Zoning designations. There will be no significant increase in demand for these services. Proposed measures to reduce or respond to such demand(s) are: The site-specific development restrictions that the proponent has proposed(see above). 7. Identify, if possible,whether the proposal may conflict with local, state, or federal laws or requirements for the protection of the environment. The proposal will not conflict with local, state or federal laws or requirements for the protection of the environment. ENV-CHECKLIST-2.F 1.doc; 05/27/99; Page: 16 LAND USE STUDY AREAS VEHICLE TRIP GENERATION REPORT Introduction The Renton City Council has requested City staff to study alternative land uses for three areas in Renton: the North Renton area including the adjacent Airport Way area, the McMahon Property area in East Renton and the Talbot Road area in Southeast Renton. The following is the traffic analysis element of the study. This report provides information on the estimated vehicle trips generated by each alternative land use proposed for each of the three study areas, compares the vehicle trips generated by each land use alternative and presents the findings resulting from the comparison. Study Areas and Land Use Alternatives The following information on the study areas and land use alternatives was provided by the Long Range Planning Section of the City of Renton. North Renton/Airport Way Study Area: The North Renton area, as shown on Figure 1, is bounded by Logan Avenue North, North 6th Street, Garden Avenue North, North 4th Street, North 3rd Place, Bronson Way and the Cedar River. The three land use alternatives identified for this area are presented in Table 1. Land Use Alternative 1, the Planning Commission proposal, has a nearly even split between single family (441 units) and multi-family use (444 units) and a majority of financial, insurance, real estate services (office) mixed with some retail, education, manufacturing and warehouse uses. Jobs and building square footage under this proposal total 2836 and 995,000 respectively. Land Use Alternative 2, the neighborhood proposal, represents existing land use and assumes no change in land use in future years. Land Use Alternative 2 has a nearly even split between single family (441 units) and multi-family (415 units) use and a majority of financial, insurance, real estate services office) use mixed with some retail, education, manufacturing and warehouse uses. Jobs and building square footage under this proposal total 2199 and 707,000 respectively. The main difference between Land Use Alternative 1 and 2 is the amount of retail, education, manufacturing and warehouse use (311,000 square feet in Alternate 1 and 117,000 square feet in Alternate 2). Land Use Alternative 3, representing requests, proposes a predominance of multi-family (923 units), financial, insurance, real estate services (office) and retail uses. Total jobs and building square footage is 3,324 and 1,112,000 respectively. The Airport Way area, also shown on Figure 1, is bounded by Airport Way, Logan Avenue South, South Tobin Street and Lake Avenue South. The three land use alternatives identified for this study area are presented in Table 1. Land Use Alternative 1, existing use, assumes the existing single and multi-family uses and the existing financial, insurance, real estate services(office), and retail and manufacturing uses wll not change in future years. Land Use Alternative 2, the Planning Commission proposal, assumes a more intense mix of financial, insurance,real estate services (office) and retail and manufacturing uses with some multi-family use (26 Units) only. Jobs and building square footage in Land Use Alternative 2 total 505 and 208,000 respectively, compared to 190 jobs and building square footage of 86,000 in Land Use Alternative 1. Land Use Alternative 3, the commercial/single family proposal, assumes a predominance of single family units (39) and one-half the jobs 252) and building square footage (104,000) for financial, insurance, real estate services (office) and retail and manufacturing uses than proposed in Land Use Alternative 2. McMahon Property Study Area: This area, as shown on Figure 2, is located east of Blaine Avenue NE and between NE 3rd/4th Street and the top of the bluff above Maple Valley Highway. The three land use alternatives identified for this study area are presented in Table 1. Land Use Alternative 1 proposes a predominance of financial, insurance, real estate services (office) with some manufacturing and a lesser amount of retail use. Total jobs and square footage for the mixed office, retail, manufacturing uses are 7028 and 2,425,000, respectively. Land Use Study Area PageVehicleTripGenerationReport December 16, 1992 Residential use is not proposed in this alternative. Land Use Alternative 2 is a 50-50 mix of single family andmulti-family dwellings. Land Use Alternative 3 has approximately 90% of the area as education use with the remainder as retail, financial, insurance, real estate services (office) and single family residential uses. Total jobsandsquarefootagefortheeducation, retail and office uses are 4279 and 2,278,000, respectively. Also included in Table 1 are estimated jobs and building square footage for existing land uses in this study area. Talhot Road Study Area: This area, as shown on Figure 3, is located north of South 192nd Street and between SR 167 and the top of the hill east of Talbot Road. The two land use alternatives identified for this study area arepresentedinTable1. Land Use Alternative 1 is totally multi-family use while Land Use Alternative 2 is a 50-50 mix of single family and multi-family units. Also included in Table 1 is the estimated dwelling units for the existing residential use in this study area. Trip Generation Estimates of dwelling units,jobs and building square footage for the land use alternatives in the three study areaswereprovidedbytheLongRangePlanningSectionoftheCityofRenton. Trip generation rates for each land use are based on information in the Institute of Transportation Engineers (ITE) Trip Generation manual (fifthedition, 1991). The trip rate per square foot of building floor area was used because the Trip Generation manualdidnotprovideinformationontriprateperemployeeforseveralofthelanduses. Detailed listings of land use data and estimated trip generated by each land use alternative in the three study areas are provided in Appendix A. Table 2 summarizes the trip generation estimates of daily and PM peak hour trips for each land use alternative in the study areas. These estimates represent average daily and PM peak hour trips and indicate future trafficdemandsonthestreetsystemafter "build-out" of each land use alternative. Also included in Table 2 are the estimated daily and PM peak hour trip generation for the existing land uses in each study area. Trip Generation by Land Use Alternative-Summary of Findings North Renton Study Area: Land Use Alternative 2 (Neighborhood Proposal) is estimated to generate the least daily and PM peak hourtrips (14,780 and 1660 respectively) of the three land use alternatives. (It should be noted that theNeighborhoodProposalisrepresentativeofexistingconditions.) Land Use Alternative 1 (PlanningCommissionProposal) is estimated to generate 18,440 daily and 2130 PM peak hour trips. Land Use Alternative 3 (Requests) is estimated to generate the most daily and PM peak hour trips (25,050 and 2930, respectively). Airport Way Study Area: Land Use Alternative 1 (representing existing conditions) is estimated to generate the least daily and PM peakhourtrips (2200 and 270, respectively) of the three land use alternatives. Land Use Alternative 3 (PlanningCommissionproposal) is estimated to generate 3010 daily trips and 380 PM peak hour trips. Land Use Alternative 2 (Commercial/Single Family) is estimated to generate the most daily and PM peak hour trips5130and650, respectively). McMahon Property Study Area: Land Use Alternative 2 (SF/4 mix) is estimated to generate the least daily and PM peak hour trips (8510 and840, respectively) of the three land use alternatives. Land Use Alternative 1 (office) is estimated to generate24,020 daily trips and 3110 PM peak hour trips. Land Use Alternative 3 (Education - Institution) is Aczt CITY OF RENTON DEPARTMENT OF PLANNING, BUILDING & PUBLIC WORKS LA rE WASHING TON. .. 1tri, 1 --% 7 tw 90 1 1 ` I sl ro, 14.l x f* a' i (.' 7.,, Dt\,.. , AIRPORT WAY STUDY AREA I LAND USE ALTERNAflVES I sr 1. EXISTING USE 7 r,7 N 3 PLANNING COMMISSION PROPOSAL(CA ZONE) I ' "? 1 ` 3. COM.'ERCIAL/SINGL£FAMILY MIX.,. . ILL j _.r r ,' _Ii:!,:iiii2.......t x .iet :IT} 1 , i. SQL f aLS! 6 Q n I C. lia:,:„ .:.‘111,;:,.,71 . , . T . .:: ] ,•:..:fARKFTTr 49 1 ,f,!..1!. 1r!' l!I..,,$i". 0-.1:-- '..•-i-/- s .;:tit : i` .L 1\N.14iLAk I....._ ci .17 1-" il i Zli kr;:C; 1 >- lfj ' J 1... NORTH RENTON STUDY AREA lern _ p LAND USE A TIVFS1. PLANNINGG COCOMMIISSION PROPOSAL G N Dr. 2. NEIGHBORHOOD PROPOSAL c 3. REQUESTS N m..4., 1{11 Vri. Z i s 7 T9 ! 2 7 Ly 11 3 Et! ST 1 5 tt FIGURE 1 4... L' itibw kJ- fir Lilt L.( _ 331; 17- Rill AdLiJr-- 1 ti g. LI 0 - 1L- 3V _ AY r--,.... ti 114 0 0 : ,. 1,-; c, j x ..................................,.................:..............r. if•-•.;.:•::::•::::•::::- f*:::. ••: ::::•::::•••••::•:?.::'...::.:*. f.:•,:*:••.:. f.•: :: :.-• 0 P. g " 15 or co:3 1 W wcfuL___ E KI. 1. 5.—.. Dr.. AY t; / . ! a = I— E- 4 0 P.:14 g . 0- Ak -• f)._. 77. 7_, ii\ v- er, _ ijtswjl' D " n- ,: i:.,.... 4.:: :::.... ttigang. t.: 3: 01: X$.::::•. Lx- 1 ---, --.iia4 ., c HQ ......._ l_ i V, ti yE LTI Si -\ , I- 150. -------' 1'. xv7--- iit$,( 61 . 1: ......:::!,,,: i... r.:•:.. E. B. H.:::•: alge.:::.::: I 4. 4. 6 D ce c0 U g aMk 11--/--- 1 Z b''''.''' 0 " " r. (. 9 Iv w w 66. 121: 4 L E Iii- Jih- iiiiii- ii L_ .. H N z J _ 19 fr" Z n _ u_, I 0.'( 14 I( •. 0 o- V 1 uu yu/ Le)). A:.::......-..... 1- 1, ' a. L.*:•;:.' ai::.:-..:: .(...,..-,.::::::.,.-....,..:. 1 Y5 z :...-,--_- 1 415 •.: - 4. 4kIN w T__7.,.. z__ 1.?. 11. IA • 0 r, H ---/ , * I AY i iilli i • I 1, ii ---- ' LIJ i a VP • liwi- KiTiu 1-', ISM vai ti 111711. 1 g. 1) tr. -—--•,„,-.--. 11- 11 _.._.. .. i=" Y s Ar Uf CITY OF RENTON DEPARTMENT OF PLANNING, BUILDING & PUBLIC WORKS IL_LLV 'll t iliCi Tr 172-.1 5 \IN crIlln g! E if:( z , s I tut 5i1 Sr j r Z I fir ? Ai I c i s-, -...) Gam , r N aj 1 rr xc, r g N i N 1t Sid rt1 > W 3rA S7 t CIE jr---\___ E t gr tt.t 1 7 1.- ---t bS b1 I 81 f 71, .tati /Z.I 0/ 4 TALBOT ROAD STUDY AREA i j LAND USE ALTERNATIVES 1. MULTI FAMILYMULTI 2. SINGLE FAMILY/4 MIX N 49 r I bi c R tom=J l. 1. // i.:-:::ir::::::...--•••- • i I RiI LijI 4...., N t Si I g 190fh ST J J 1 tinii I i [...... —lr."--- i_ Ein _.z-----i• e FIGURE 3 I TABLE 1 STUDY AREA LAND USE ALTERNATIVES NORTH RENTON I AIRPORT WAY STUDY AREA LAND USE ALTER*IATIVE I ALTERNATIVE 2 ALTERNATIVE 3 EXISTING PLANNING COMMISSION PROPOSAL NEIGHBORHOOD PROPOSAL REQUESTS NORTH RENTON AREA 42 Units 441 Units Single Family 441 Units 441 Units Multi-Family 444 Units 415 Units 923 Units 415 Units Total 385 856 965 856 Retail 240 Jobs 108,000 Sq.Ft. 128 Jobs 58,000 Sq.Ft. 709 lobs 319,000 Sq.Ft. 128 Jobs 58.000 Sq. Education 76 Jobs 46.000 Sq.Ft.40 Jobs 24,000 Sq.Ft.0 0 40 Jobs 24,000 Sq. Manufacturing 201 Jobs 111,000 Sq.Ft.63 Jobs 35,000 Sq.Ft. 26 Jobs 16,000 Sq.Ft. 63 Jobs 35,000 Sq. Financial,Insurance,Real Estate Services(FIRES) 2231 Jobs 684,000 Sq.Ft. 1968 Jobs 590,000 Sq.Ft. 2589 Jobs 777,000 Sq.Ft. 1968 Jobs 590.000 Sq. Warehouse 24 Jobs 46.000 Sq.Ft. 0 0 0 0 0 Total 2336 995,000 2199 707.000 3324 1,112.000 2199 707,000 ALTERNATIVE 1 ALTERNATIVE 2 ALTERNATIVE 3 EXISTING EUISTTNG USE PLANNING COMMISSION PROPOSAL COMMERCIAL/SINGLE FAMILY CA ZONE) AIRPORT WAY AREA 0 Units 39 Units 18 Units IS UnitsSingleFamily1 Multi-Family 3 Units 19 Units 19 Units 26 UnitsUnits Total 37 26 52 37 Retail 70 Jobs 32,000 Sq.Ft. 202 Jobs 91,000 Sq.Ft. 101 Jobs 45,000 Sq.Ft.70 Jobs 32,000 Sq. Manufacturing 70 Jobs 39,000 Sq.Ft. 101 Jobs 56,000 Sq.Ft. 50 Jobs 28,000 Sq.Ft.70 Jobs 39,000 Sq. Financial.Insurance.Real Estate Services(FIRES) 50 lobs 15.000 Sq.Ft. 202 Jobs 61.000 Sq.Ft. 101 Jobs 31.000 Sq.Ft.50 Jobs 15,000 Sq. Total 190 86.000 505 208,000 252 104,000 190 86.000 McMAHON PROPERTY STUDY AREA LAND USE ALTERNATIVE 1 ALTERNATIVE 2 ALTERNATIVE 3 EXISTING OFFICE SINGLE FAMILY/4 MIX SINGLE FAMILY/EDUCATION- INSTITUTION CENTER Single Family 0 575 Units 45 Units 0 0 5_75 Units Multi-Family Total 0 1150 45 Retail 351 Jobs 158.000 Sq.Ft.0 0 214-Jobs 96,000 Sq.Ft. 0 0 0 0 0 0 3209 Jobs 1,925.000 Sq.Ft. 0 0 Education 0 0 10 lobs 6,000 Sq. Manufacturing 1054 Jobs 508,000 Sq.Ft.0 0 Financial.Insurance.Real 257,000 Sq.R. E.uate Services(FIRES) 5623 Jobs 1.637.000 Sq.Ft.0 0 356 Jobs 195 Jobs 59.000 Sq Total 7028 2,425.000 0 0 4279 2,278,000 205 65,000 TALBOT ROAD STUDY AREA LAND USE ALTERNATIVE 1 ALTERNATIVE 2 EXISTING MULTI FAMILY SINGLE FAMILY/4 MIX 305 to 450 Units 25 Units Single Family 0 0 Multi Family 940 to 1210 Units 305 to 450 Units 25 Total 940 to 1210 610 to 900 Source: City of Renton Long Range Planning Section Rt-M)MA:TI REVhwljb TABLE 2 LAND USE STUDY AREAS SUMMARY OF VEHICLE TRIP GENERATION PROPOSED LAND USE EXISTING LAND USE STUDY AREA ESTIMATED ESTIMATED ESTIMATED ESTIMATED DAILY TRIPS PM PEAK DAILY TRIPS PM PEAK HOUR TRIPS HOUR TRIPS North Renton Land Use Alternative 1 18,440 2130 14,780 1660 Planning Commission Proposal) Land Use Alternative 2 * 14,780 1660 Neighborhood Proposal) Land Use Alternative 3 25,050 2930 14,780 1660 Requests) Airport Way Land Use Alternative 1 2200 270 Existing Use) Land Use Alternative 2 5130 650 2200 270 Planning Commission Proposal) Land Use Alternative 3 3010 380 2200 270 Commercial/Single Family) Represents existing land use McMahon Property Land Use Alternative 1 24,020 3,110 950 130 Office) * * Land Use Alternative 2 8,510 840 950 130 Single Family/4 Mix) Land Use Alternative 3 32,070 2,950 950 130 Single Family/Education Institution) Includes retail and manufacturing as supporting uses. Talbot Road Land Use Alternative 1 5300 to 6500 480 to 590 300 30 Multi Family) Land Use Alternative 2 4870 to 6800 470 to 630 300 30 Sinele Family /4 Mix) RLUI-3/ww/A:T1b Land Use Study Area Page 3 Vehicle Trip Generation Report December 16, 1992 estimated to generate 32,070 daily trips and 2950 PM peak hour trips. Land Use Alternative 3 generates 160 less PM peak hour trips than Land Use Alternative 1. This minor difference in PM peak hour trips is attributable to differences in peaking characteristics between office and education uses. All three land use alternatives generate significantly more trips than the existing land uses. For Land Use Alternatives 1 and 3, the combination of location, topography, existing traffic level of service, aquifer and adjacent single family neighbors make for an exceptionally challenging situation to addressing transportation needs. The trip generation indicates SOV needs equivalent to a 50% increase in capacity on Sunset Blvd. at N. 3rd and Maple Valley Highway intersections. Both of these intersections are currently operating at level of service F. Capacity improvements would require costly grade separations on Sunset Blvd. and Maple Valley Highway, I-405 revisions and extensive R/W acquisition. In addition, such improvements would be located in Zone 1 of the aquifer and would set up travel patterns that could have very negative impacts on residential neighborhoods, particularly in the Highlands. Therefore, the magnitude of new office development proposed in Land Use Alternative 1 must be located west of I-405 near regional transit centers. The institutional zoning proposed in Land Use Alternative 3 has some potential, but it would need to be greatly scaled down in terms of trip generation. Each of the three land use alternatives could generate transit ridership; however, the densities proposed under Land Use Alternatives 1 and 3 should be located along future regional transit service connections. Talbot Road Study Area: Land Use Alternative 1 (Multi-family) is estimated to generate from 5300 to 6500 daily trips and 480 to 590 PM peak hour trips. Land Use Alternative 2 (Single Family/Multi-Family Mix) is estimated to generate 4870 to 6800 daily trips and 470 to 630 PM peak hour trips. At the low end of the range of estimated daily and PM peak hour trips, Land Use Alternative 2 generates less daily and PM peak hour trips than Alternative 2. At the high end of the range of estimated daily and PM peak hour trips, Land Use Alternative 1 generates less daily and PM peak hour trips. This reversal in trip generation is attributable to assumptions that multi-family use has a greater potential to generate transit ridership than single family use. Therefore, as the number of multi-family units increase, transit ridership increases and fewer vehicle trips are generated. Both land use alternatives could generate transit ridership. For the reason stated above, Land Use Alternative 1 has higher transit ridership potential. R L.M J/ww•/A:LUSTUDYv APPENDIX A Study Area Land Use and Estimated Trip Generation TABLE A-1 NORTH RENTON /AIRPORT WAY STUDY AREA Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Airport Way Alternative 1 - Existing Use Single Family d.u. 18 11.8 212 1.28 23 Multi Family d.u. 19 10.7 203 0.82 16 Retail 1000 gsf 32 40.67 1300 4.93 158 Manufacturing 1000 gsf 39 3.55 138 0.75 29 Office(FIRES *) 1000 gsf 15 23.1 347 3.16 47 Warehouse 1000 gsf 0 Total: 2200 273 Airport Way Alternative 2 - Planning Commission Proposal Single Family d.u. 0 Multi Family d.u. 26 10.11 263 0.77 26 Retail 1000 gsf 91 40.67 3.700 4.93 449 Manufacturing 1000 gsf 56 3.64 203 0.75 42 Office(FIRES *) 1000 gsf 61 15.84 966 2.12 129 Warehouse 1000 gsf 0 Total: 5132 646 Airport Way Alternative 3 - Commercial /Single Family Single Family d.u. 39 11 429 1.18 46 Multi Family d.u. 13 5 150 0.86 11 Retail 1000 gsf 45 40.67 1830 4.93 223 Manufacturing 1000 gsf 28 3.41 96 0.75 20 Office(FIRES *) 1000 gsf 31 19 509 2.57 80 Warehouse 1000 gsf 0 Total:3014 380 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units gsf = gross square footage of floor area Source: Daily and PM peak hour trip rates per unit based on information in the Institute of Transportation Engineers ITE) Trip Generation manual (5th edition, 1991) RLM.3'. /A:TA3rb k TABLE A-1 NORTH RENTON /AIRPORT WAY STUDY AREA Summary of Land Use and Estimated Trip Generation 1 DAILY DAILY PM PEAK PM PEAK LAND USE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS North Renton Alternative 1 - Planning Commission Proposal l Single Family d.u.441 9.18 4,048 0.94 412 Multi Family d.u.445 6.09 2.710 0.55 250 Retail 1000 gsf 108 40.67 4,390 4.93 532 Education 1000 gsf 46 11.2 515 0.28 13 1 Manufacturing 1000 gsf 111 3.77 418 0.75 83 1 Office(FIRES *) 1000 gsf 684 8.77 6,000 1.12 766 Warehouse 1000 gsf 46 7.76 357 1.67 78 1 Total: 18,438 2,134 North Renton Alternative 2 - Neighborhood Proposal 1 Single Family d.u.441 9.18 4,048 0.94 415 Multi Family d.u.415 6.16 2,556 0.56 232 Retail 1000 gsf 58 40.67 2,359 4.93 286 Education 1000 gsf 24 13.46 323 0.28 7 I Manufacturing 1000 gsf 35 3.51 123 0.75 26 Office(FIRES *) 1000 gsf 590 9.10 5,369 1.17 690 Warehouse 1000 gsf 0 Total: 14,778 1,656 I North Renton Alternative 3 - Requests Single Family d.u. 42 11 462 1.20 50 T Multi Family d.u.923 5.34 4,929 0.48 443 Retail 1000 gsf 319 40.67 12,974 4.93 1573 Education 1000 gsf 0 Manufacturing 1000 gsf 16 3.85 61 0.75 12 Office(FIRES *) 1000 gsf 777 8.53 6,628 1.09 847 Warehouse 1000 gsf 0 Total: 25,054 2,925 a North Renton - Existing Land Use I Single Family d.u.441 9.18 4,048 0.94 415 Multi Family d.u.415 6.16 2,556 0.56 232 Retail 1000 gsf 58 40.67 2,359 4.93 286 Education 1000 gsf 24 13.46 323 0.28 7 a Manufacturing 1000 gsf 35 3.51 123 0.75 26 Office(FIRES *) 1000 gsf 590 9.10 5,369 1.17 690 Warehouse 1000 gsf 0 Total: 14,778 1,656 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units gsf = gross square footage of floor area Source: Daily and PM peak hour trip rates per unit based on information in the Institute of Transportation Engineers ITE) Trip Generation manual (5th edition, 1991) RLit•3/,.w A:TA3r,b TABLE A-2 les000. 000000 McMAHON PROPERTY Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE TYPE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Alternative 1 - Office Single Family d.u. 0 Multi Family d.u. 0 Retail 1000 gsf 158 40.67 6,425 4.93 780 Education 1000 gsf 0 Manufacturing 1000 gsf 580 3.85 2,235 0.75 435 Office(FIRES *) 1000 gsf 1687 9.11 15,370 1.12 1890 Warehouse 1000 gsf 0 Total: 24,020 3105 Alternative 2 - Single Family/4 Mix Single Family d.u.575 9 5,175 0.91 525 Multi Family d.u.575 5.82 3,345 0.54 310 Retail 1000 gsf 0 Education 1000 gsf 0 Manufacturing 1000 gsf 0 Office (FIRES *) 1000 gsf 0 Warehouse 1000 gsf 0 Total: 8,510 835 Alternative 3 - Single Family/Education-Institution Center Single Family d.u. 45 11 495 1.17 53 Multi Family d.u. 0 Retail 1000 gsf 96 40.67 3,905 4.93 473 Education 1000 gsf 1925 12.87 24,775 1.06 2040 Manufacturing 1000 gsf 0 Office(FIRES *) 1000 gsf 257 11.24 2,890 1.47 379 Warehouse 1000 gsf 0 Total: 32,065 2,945 Existing Land Use Manufacturing 1000 gsf 6 3.33 20 0.75 5 Office(FIRES*) 1000 gsf 59 15.84 930 2.12 1')5 950 130 FIRES = Financial, Insurance, Real Estate Services d.u. = dwelling units 2SI = gross square footage of floor area KLML3'..../A;TA:jb 0 TABLE A-3 TALBOT ROAD STUDY AREA Summary of Land Use and Estimated Trip Generation DAILY DAILY PM PEAK PM PEAK LAND USE TYPE UNITS QUANTITY TRIPS TRIPS HOUR TRIPS HOUR PER UNIT PER UNIT TRIPS Alternative 1 -Multi Family Multi Family d.u. 940 5.62 5300 0.51 480 or Multi Family d.u. 1210 5.37 6500 0.49 590 Alternative 2 - Single Family/4 Mix Single Family d.u. 305 9.45 2,880 0.97 296 Multi Family d.u. 305 6.51 1.985 0.58 177 Total: 4,865 473 or Single Family d.u. 450 9.11 4100 0.87 390 Multi Family d.u. 450 6 2700 0.54 240 Total:6800 630 Existing Land Use Single Family d.u. 25 12 300 1.2 30 Multi Family d.u. 0 Total:300 30 Ki.m.3, /A:TAJjb 9 T23N R5E W 1/2 1 . 1'C1!Wale A lication 99-M-3CRfit: PP R-8 R-8 NE 4th St.IIR-8 R _I i i1. ;C A ; cA] z R-10 R-10 2. 0 RM—I t, NI 1 i R-8 ILCP) RMH F+ i Z N z z el F i RMH C I 1R-8 N w RC y RC R-g'.6,/, R, i. C(P) aIf1. 44Pcv 1,4 S R C R ' 8 R,'8 G5 . 21T23NR5EW1/2 410 54-6. ZONING vices t:aeoo 16 TrAN R KR W 1/2 Comprehensr Plan Amendmen 99-M-3 Attachment B: Neighborhood Detail & Existing Zoning i\ri I 1 1 J 1 R - 10 R - 10 CD 1) L i ------- 1 I I\ ' IR---8 I L OD ) 1 RMH 1 \1 j 1 1 1 1 1 I R-Ell 1 RMH I9 RC i 1 RC\ 0 Neighborhoods & Strategic Planning RECEIVED Property Boundar O. Dennison 0 12 May 1999 MAY 2 7 1999 Zone boundaries 0 500 1 ,000 st.JILLANG DIVISION 1 :6,000 CITY OF RENTONLAPIANTA'S PLANNED RESIDENTIAL FIECEIVED DEVELOPMENT DISTRIBUTION AS OF 5/27/99 MAY 271999 VILLAGE A: BUILDING DAnsgotj TOTAL NUMBER OF UNITS 101 One-Story Ramblers (conventional single-family) 40 Two-Story Townhouses 61 Anticipated Unit Designs: Ramblers: One and Two Bedroom plus den Townhomes: Two and Three Bedroom Anticipated Buyer Profile:Primarily"move-down"buyers, retirees, persons soon-to retire, and widows and widowers. VILLAGE B: TOTAL UNITS 160 Stacked Flats (two-story in max. six-unit buildings) 78 Two Story Townhomes 82 Anticipated Unit Designs: Stacked Flats: One bedroom and one bedroom plus den Two bedroom, two bedrooms plus den and Three bedroom Townhomes: Two and Three bedroom plus den Anticipated Buyer Profile:Singles,young professional couples, senior citizens (singles and couples), relatively few children. VILLAGE C: TOTAL HOMES 47 (all conventional single-family homes) Anticipated Unit Designs: Two,Three and Four bedroom single-family detached Anticipated Buyer Profile:35 years and older. Moving up to second home. Families with children. VILLAGE D: TOTAL HOMES 15.2(all conventional single-family homes) Anticipated Unit Designs: Two,Three and Four bedroom single-family detached homes Anticipated Buyer Profile:Young professionals (both single and married), move-down "couples". Relatively few children due to lot and home sizes. DODDS ENGI CITY OF REiERECEWEDTON MEMO MAY 2 7 1999 BUILDING DIVISION Date: May 26, 1999 DEI Project No. 99015 To: David Halinen From: Craig Krueger Re: La Pianta Comp Plan Amendment/Rezone Impervious Surface Calculations Attached you will find the detention calculations prepared by another consultant for Basins 1 and 2 for the approved Cedar Crest development (402 manufactured homes). For the purposes of this analysis, we have assumed that many of the impervious surface calculations will be consistent for the proposed mixed use plan since the road pattern, road width, water quality ponds, etc. will remain very similar to the Cedar Crest layout. The areas that will change are 1) the "impervious areas on lots" and 2) the RV Storage Area, which is being deleted from the development. Below you will find a comparison of the "impervious area on lots" for the two basins which compares the assumptions made for Cedar Crest against the mixed use proposal with townhouses, carriage flats, and single family homes. You will note that, while the mixed use proposal calls for an increase in the number of units, the size of the footprints for the townhouses, carriage flats and alley homes are much smaller than the 2876 square feet assumed for the manufactured homes. Basin #1 Comparison of impervious area on lots. Approved plan 2876 sf x 209 lots= 13.80 ac. Proposed Concept Village A 101 TH x 1700 sf/TH = 3.94 ac. Village B 82 TH x 1700 sf/TH = 4.96 ac. 78 carriage flats x 980sf/DU 1400 if of 20' wide alley = 0.64 ac. Total= 9.54 ac. Planning•Engineering•Surveying 4205-148th Avenue NE Suite 200 Bellevue,Washington 98007 Tel.425-885-7877 Fax.425-885-7963 99015L#1.doc E Mail.once@DElonline.com 5/27/99 Mr. Dave Halinen Pg: 2 Additional reduction in impervious area RV storage area deleted= 1.94 ac Basin #2 Comparison of impervious are on lots Approved plan 2876 sf x 200 lots = 13.20 ac. Proposed concept Village C 46 SFD @ 2876/DU= 3.10 ac. Village D 76 trad. @ 2000/DU= 6.63 ac. 76 alley @ 1800/DU Alleys @ 1200 if x 20' wide= 0.55 Total= 10.28 ac. Total impervious area for approved plan 45.04 ac. Total impervious area for proposed plan 35.90 ac. Net reduction 9.14 ac. Net %reduction 20% DETENTION CALCULATIONS Basin #1, as shown on the Pipe Tributary Area Exhibit in the Appendix, includes the on-site developed areas of Phases 1 and 2 of the project as well as the full width of Edmonds Avenue from N.E. 3rd Street to the Plat of La Colina. The specific areas, which were included in the facility sizing calculations, have been summarized in the table below. The table shows the areas calculated for each of the different land covers in the developed condition for the areas tributary to Pond A, the Basin #1 conveyance system, and the Emergency Overflow Pipe. SUMMARY OF AREAS USED IN CALCULATIONS Location Impervious Pervious Pond A Basin#1 Overflow Area Area Sizing Convey- Pipe acres) (acres) ance Sizing CN=98 CN=68 System Sizing' Interior Roads &Sidewalk 7.32 X X X Impervious Area on Lots (2,876 s.f./lot * 209 lots)13.80 X X X Edmonds Avenue(On-Site) 1.54 X X X Edmonds Avenue(Off-site) 0.26 X X X R.V.Storage Area 1.94 1.45 X X X Community Center 0.67 0.41 X X X Detention/Infiltration Pond A (Incl.surrounding area) 3.68 X X Water Quality Pond A 0.44 X X Detention/Infiltration Pond B (Incl.in Basin#2 area) 0.61 X Basin#1 Pervious Areas(Lots,landscaping,etc.) 18.65 X X X Bypass Area(Slope in N.E. corner of site)4.30 X Bypass Area(Depression area in N.W.corner of site) 1.47 Off-site Tributary Area(Area along east property line)3.01 X Basin#2 Areas(Includes Pond C and off-site trib.areas) 19.07 21.24 X Acreage Totals 50.16 j57 97.78_ Total Impervious 25.97 22.92 45.04 Total Pervious 24.19 18.0 _ .74 Existing Conditions Tributary Area: 50.16 Ac. (area tributary to Pond A)-0.26 Ac. (Edmonds Ave.off-site) 0.61Ac. (Pond B)+4.30 Ac. (N.E.slope bypass area)=54.81 Ac. The totals for this column represent the areas used in the hydrograph flow calculations. For the R.V. Storage and Community Center areas(Impervious: 1.94+0.67=2.61,Pervious: 1.45+0.41 = 1.86),which are also marked with an"X" in this column,the flows were calculated using the Rational Method. The detention calculations were performed using Engenious Systems Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A (User 1) 24-hour rainfall distribution. Separate S.C.S. curve numbers were used for the impervious and pervious portions of the site. Using the onsite existing condition hydrographs, the allowable release rates were determined for the site in accordance with City of Renton standards. Developed condition hydrographs were then generated for the bypass areas in order to verify that the developed bypass flows did not exceed the pre-developed peak runoff rates for each of the 2, 10,and 100-year,24-hour storm events. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 7 Phases 1 & 2 DETENTION CALCLLeiTIONS Basin #2, as shown on the Pipe Tributary Area Exhibit in the Appendix, includes the on-site developed areas of Phases 3 and 4 of the project, as well as the approximately 4-acre future park area in the southwest corner of the site. The specific areas, which were included in the facility sizing calculations, have been summarized in the table below. The table shows the areas calculated for each of the different land covers in the developed condition for the areas tributary to Pond C, the Basin #2 conveyance system, and the Emergency Overflow Pipe. SUMMARY OF AREAS USED IN CALCULATIONS Location Impervious Pervious Pond C Basin#2 Overflow Area Area Sizing Convey- Pipe acres) (acres) ance Sizing CN=98 CN=68 System Sizing' Interior Roads &Sidewalk 5.35 X X X Impervious Area on Lots(2,876 s.f./lot* 200 lots)13.20 X X X Basin#2 Pervious Areas (Lots,landscaping,etc.) I 13.88 I X X X Detention/Infiltration Pond C(Incl.surrounding area) 1.85 X X Water Quality Pond C 0.52 X X Detention/Infiltration Pond B 0.61 - X X Pervious Future Park Area (S.W.corner of basin) 3.95 X X X Off-site Bypass Area(Along northern basin boundary)0.95 X Basin#1 Areas(Incl. bypass and off-site tributary areas) 25.97 31.50 X Acreage Totals 39.36 3 .43, 97.78 Total Impervious 19.07 118.55 C475.04 Total Pervious 20.29 13.88 52.74 Existing Conditions Tributary Area: 39.36 Ac.(area tributary to Pond C) 0.61 Ac. (detention/infiltration Pond B) 38.75 Ac. The totals for this column represent the areas used in the hydrograph flow calculations. For the Future Park area, which is also marked with an"X"in this column,the flows were calculated using the Rational Method. The detention calculations were performed using Engenious Systems Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A(User 1) 24-hour rainfall distribution. Separate S.C.S. curve numbers were used for the impervious and pervious portions of the site. Using the onsite existing condition hydrographs, the allowable release rates were determined for the site in accordance with City of Renton standards. Developed condition hydrographs were then generated for the bypass areas in order to verify that the developed bypass flows did not exceed the pre-developed peak runoff rates for each of the 2, 10, and 100-year, 24-hour storm events. This analysis can be found in the Cedar Crest—Phases I & II—Storm Drainage Report. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 7 Phases 3 & 4 E wS I 10 MEMODD ° L ooc VlE-,Go, traffic design transportation planning 1319 Dexter Avenue North Seattle,Washington 98109 206)285-9035 Suite 270 FAX 285-6345 TABLE 1 TRIP GENERATION COMPARISON LA PIANTA SITE — RENTON CONVENTIONAL SF LOT CAPACITY (UNDER R-8 PLANNED RESIDENTIAL REGULATIONS) & APT. DEVELOPMENT DISTRIBUTION CAPACITY (UNDER RM—I AS OF 05/27/99 REGULATIONS) 239 SF 221 TOTAL 413 SF 18 MF TOTAL TIME PERIOD LOTS T.H. TRIPS LOTS UNITS TRIPS Daily 2287 1295 3582 3952 119 4071 AM Peak Enter 45 16 61 78 1 79 Exit 134 81 215 232 8 240 Total 179 97 276 310 9 319 PM Peak Enter 154 80 234 267 7 274 Exit 87 39 126 150 4 154 Total 241 119 360 417 11 428 NOTE: The trip rates for ITE Land Use Code 210, Single-Family Detached Housing, were used for the ramblers in Village A, all of Villages C and D (which are entirely single-family detached) , and the 413 single-family lots considered for comparison purposes. The trip rates for Land Use Code 230, Residential Condominium/Townhouse, were used for the proposed townhouses and stacked flats in Villages A and B. Land Use Code 220, Apartments, was used for the 18 apartments (allowed under the RM-I regulations) . CITY OF RENTTON RECEIVED MAY 271999 SLIDING DIVISION HALINEN LAW OFFICES, P.S. A Professional Service Corporation David L. Halinen,P.E. Bellevue Place/Seafirst Building 425)454-8272 10500 NE 8th,Suite 1900 Fax(425)646-3467 Bellevue,Washington 98004 May 27, 1999 HAND-DELIVERED CITY OF RENTON City of Renton Department of Economic Development and RECEIVED Neighborhood Strategic Planning MAY 2 719991055S. Grady Way, Sixth Floor Renton, Washington 98055 BUILDING VISION Attn: Rebecca Lind, Senior Planner RE: La Pianta Limited Partnership's Amendments to its March 31, 1999 Application for (1) Comprehensive Plan Land Use Map Amendments and Rezone and (2) Text Amendments to both (a) Comprehensive Plan Policy LU-61 and (b) Portions of the R-14 Zone Regulations Dear Ms. Lind: As a follow-up to my recent phone conferences and meetings with you, with Susan Carlson, and with other City of Renton staff members, on behalf of La Pianta Limited Partnership ("La Pianta"), a Washington limited partnership, I herewith submit to you the following items as an amendment to La Pianta's above-referenced March 31, 1999 application: 1) Twelve (12) copies (including the original) of this letter; 2) Twelve(12) copies of an amended Master Application form signed on behalf of La Pianta; 3) Twelve (12) copies of an amended Property Map (which depicts, among other things, the boundaries of both the proposed Comprehensive Plan Land Use Map designations and the proposed zones, proposed on-site recreational areas, and the proposed locations of four currently-planned residential villages); 4) Twelve (12) copies (including the original) of an amended Environmental Checklist signed by Mr. Craig Krueger of Dodds Engineers, Inc. (along with two sets of binders entitled"Storm Drainage Report" for "Cedar Crest Phases I, II, Ill and IV" prepared by Triad Associates and dated February 11, 1999, which binders also contain various supporting geotechnical reports and a hydrogeological report prepared by other consulting firms) ; 5) Twelve(12) copies of a Trip Generation Table prepared by the traffic analysis consulting firm David I. Hamlin & Associates; City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner May 27, 1999 Page 2 6) Twelve (12) copies of a May 26, 1999 Memo from Dodds Engineers, Inc. regarding "Impervious Surface Calculations"; 7) Twelve (12) copies of an amended Project Narrative; 8) Twelve (12) copies of a Single-Family Residential Analysis Map; and 9) Twelve (12) copies of "La Pianta's Planned Residential Development Distribution as of 5/27/99". During our meeting prior to the March 31 st submittal, you deferred the usual requirement for submittal of PMT reductions of the maps(item 12 on the City's application requirements list). Please advise me as to when PMT reductions will be required and I will arrange to have them promptly submitted. Summary of the Amendments to the Originally-Submitted Application Reduction of the R-14-Proposed Acreage and Increase of the R-10 Proposed Acreage The originally-submitted application requested that (a) approximately 42.6 acres of the site be given a Residential Options(RO) Land Use Map designation and corresponding R-10 zoning and b) approximately 53.6 acres of the site be given a Residential Planned Neighborhood (RPN) Land Use Map designation and corresponding R-14 zoning. In contrast, the hereby-amended application requests that(a) approximately 74.2 acres of the site be given a Residential Options (RO) Land Use Map designation and corresponding R-10 zoning and (b) 20 acres of the site (the minimum size permitted under Comprehensive Plan Policy LU-57) be given a Residential Planned Neighborhood RPN) Land Use Map designation and corresponding R-14 zoning. The locations of the requested Land Use Map designations and zoning classifications is set forth on the accompanying amended Property Map. Elimination of the Proposed Text Amendments to both (a) Policy LU-61 and (b) Corresponding Portions of the R-14 Zone Regulations The originally-submitted application requested a text amendment to Comprehensive Plan Policy LU-61 that would have had it read as follows (with the requested new text underlined): City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner May 27, 1999 Page 3 Policy LU-61. Longer townhouse building clusters, and other multi-family building clusters, considered secondary residential types, should be limited in size so that the mass and scale of the cluster retains a small scale multi-family character rather than a garden apartment development style, with an exception for portions of projects in the Residential Planned Neighborhood designation where the residents are legally age- restricted to persons 55 years of age or older consistent with applicable Federal law. Limits on the number of units which may be attached in one cluster should be established in the development regulations. Consistent with that proposed amendment to Policy LU-61, La Pianta also originally requested text amendments to the R-14 regulations that would have: 1) Provided for"senior apartment buildings" as Secondary Units within the R-14 zone with (a) the overall number of flats in such buildings in each R-14 development limited by the 50% Secondary Uses limitation of the R-14 zone and (b) no zoning limitation on the number of flats in each such building; 2) Provided for no minimum lot size for senior apartment buildings; 3) Provided a special height limit for senior apartment buildings that would accommodate up to four stories (on the order of 45 feet) for situations like that of the La Pianta site where topographic conditions will allow such building(s) to be constructed adjacent to the lower side of an existing slope or bank; and 4) Provided special parking regulations for senior apartment buildings (to be developed with Renton Strategic Planning staff later during the Comprehensive Plan Amendment/Rezone review process). La Pianta hereby withdraws all of those previously-requested text amendments. Specification of Site-Specific Development Restrictions to be Incorporated into a Development Agreement The major emphasis of the proposal is to provide an opportunity for a residential development with a mix of urban residential forms while maintaining a development intensity that it is roughly comparable to conventional, detached single-family development. (In addition, a small part of the proposal is to provide for a convenience commercial area that will be well-situated to serve the development and the adjacent La Colina development.) To ensure that this emphasis will be achieved, City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner May 27, 1999 Page 4 La Pianta has had three different analyses performed to provide baseline conditions for development restrictions to be embodied in a Development Agreement between the City and La Pianta and recorded to run with the land. First, Dodds Engineers has evaluated the number of conventional, detached single-family lots that could reasonably be achieved on the portion of the subject site that is currently designated Residential Single Family (i.e., all of the site other than the 0.92-acre portion that is designated Residential Multi-Family Infill) under the R-8 zoning regulations. Dodds has determined that 413 such lots could reasonably be achieved. (See the Single-Family Residential Analysis Map.) Further, based upon an allowable density of 20 units per acre in the Residential Multi-Family Infill zone, approximately 18 units would be permitted in the 0.92-acre portion that is designated RM-I. Second, the traffic analysis consulting firm David I. Hamlin & Associates has calculated the anticipated number of average daily trips that would be generated by 413 conventional, detached single-family residential lots and 18 multi-family units. As noted on the accompanying Trip Generation Table, 3,952 average daily trips would be anticipated for that many lots and 119 average daily trips would be anticipated for that many multi-family units for a total of 4,071 average daily trips. Third, as described in the accompanying May 26, 1999 Memo from Dodds Engineers regarding"Impervious Surface Calculations", Dodds has reviewed the detailed stormwater detention calculations for the previously-approved (and still vested) "Cedar Crest Manufactured Home Park" to determine the amount of impervious surface that was anticipated for the La Pianta site under that development proposal. (Those calculations were set forth in the accompanying February 11, 1999 Storm Drainage Report" for Cedar Crest Phases I, II, III and IV prepared by Triad Associates.) Dodds has determined from its review of those calculations that a total of 45.04 acres of impervious surface were anticipated for Cedar Crest. The Dodds memo also notes that the total impervious area for the proposed development concept (see the accompanying sheet entitled "La Pianta's Planned Residential Development Distribution as of 5/27/99", which is discussed below) would only include approximately 35.9 acres, 9.14 fewer acres than anticipated for the approved Cedar Crest project. In view of these three analyses, La Pianta proposes that the requested comprehensive plan designations and zoning be granted subject to a Development Agreement that would embody the following site-specific restrictions (the"Proposed Site-Specific Restrictions"): 1) Permitted residential development in the proposed R-I 0 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the number and type of residential units in combination with the building square footage of City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner May 27, 1999 Page 5 convenience commercial development would not be expected to generate more than 4,071 average daily trips as calculated under the 1997 Institute of Transportation Engineers (I E)Manual; 2) Permitted residential development in the proposed R-10 and R-14 portions of the site and permitted convenience commercial development in the proposed CC portion of the site would be limited so that the total impervious surface coverage due to the combined residential and convenience commercial development would not be expected to exceed a total of 45.04 acres; 3) The overall number of residential units of any type could not exceed 490 units; and 4) The overall number of flats (which would only be constructed in the R-14- zoned portion of the site) could not exceed 78 units and the number of flats in any such building could not exceed 6 units. Please note that the currently-anticipated distribution of the residential portion of the site is set forth on the accompanying sheet entitled "La Pianta's Planned Residential Development Distribution as of 5/27/99." Only 460 overall units are anticipated under that distribution in four villages. The locations of the villages are generally depicted on the accompanying Property Map. Recognition That a 0.92-Acre Portion of the Site is Already Zoned "RM-I" and Request That That Portion Be Zoned "Convenience Commercial" When the original application was submitted, the applicant was unaware that the northwesterly-most 0.92-acre portion of the site is currently zoned Residential Multi-Family Infill RM-I) (with a corresponding Land Use Map designation). At that time, the applicant contemplated the possibility for commercial development of a small portion of the site consistent with the R-14 zone regulations to serve primarily the surrounding residential development. After (1) you discovered and pointed out to us the fact that the northwesterly-most 0.92-acre portion of the site is currently zoned Residential Multi-Family Infill (RM-I) and (2)the applicant has had an opportunity to consider the development potential for that portion of the site, the applicant has decided as part of the other amendments to hereby request that this portion of the site be designated and zoned Convenience Commercial (CC). This portion of the site is appropriately sized for a convenience commercial development and, as situated at the northerly end of the Edmonds Avenue extension, it will be able to serve both the subject proposal and the adjacent, planned 138-residential lot La Colina single- family residential subdivision to the west, making the location of a convenience commercial site more efficient there than within the proposed R-14 portion of the site. Not only is the 0.92-acre portion City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner May 27, 1999 Page 6 appropriately-suited for convenience commercial, it too small for an efficient, stand-alone multi-family in-fill development, making the requested change all the more appropriate. Because CC zoning of the 0.92-acre portion of the site will obviate the need for commercial development within the proposed R-14 portion of the site, the applicant is willing to stipulate in the Development Agreement that no commercial development will be permitted in the proposed R-14 potion of the site as long as the 0.92-acre portion of the site is zoned CC. We look forward to addressing the Planning Commission and City Council concerning the amended request. Please phone me if you have any questions or comments. Thank you for your cooperation. Sincerely, HALINEN LAW OFFICES, P.S. I David L. Hali en Enclosures cc: La Pianta Limited Partnership Attn: Mario Segale and Ann Nichols (with copies of enclosures) Donald J. Merlino (with copies of enclosures) Gary M. Merlino (with copies of enclosures) Richard Gilroy (with copies of enclosures) Craig Krueger, Dodds Engineers, Inc. (with copies of enclosures) D:\CF\2009\040\LIND.LT2.Fl.wpd N V 8 . a N V 9 CJEZEIMaa Etwwwwl 01IMM] BUJ P acid I vd am I s aivds awnd a tvd City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: LID VIu'411L . ^t OMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 LOCATION: SE Quadrant of NE 3'd/NE 4th and Edmonds Ave. extension SITE AF'EA: 96.2 acres BUILDING AREA(gross): N/A SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zoning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. EA'VIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element 31 the Probable Probable More Element of the Probable Probable More Environment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Wafer Light/Glare Plants Recreation Land/Shcreline Use Utilities Animals Transportation Environnental Health Public Services Energy/Historic/Cultural Natural F'asouroes Preservation Airport Environment 10,000 Feet 14,000 Feet B. PCLICY-RELATED COMMENTS C. CODE-RELATED COMMENTS We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas whey ditional inf rmation is needed to properly assess this proposal. 77. ignature f irector or A tho' ed Representative Date DEVAPP Rev.10/93 CITY OF RENTON E I) PLANNINGBUILDING/PUBLIC WORKS APR 2 7 4999 MEMORANDUM Ern DATE: April 27, 1999 TO: Rebecca Lind yy FROM: Sonja J. Fesser u SU,JECT: LaPianta Rezone & Comp. Plan Amendment Legal Description and Map Exhibit Review Bob Mac Onie and I have reviewed the above referenced rezone and comprehensive plan amendment submittal and have the following comments: The applicant needs to provide legal descriptions for the areas proposed as R-10 and R-14 zones. The map exhibit should note bearings and distances that better define the line separating the R-10 zone from the R-14 zone. In future, it would be helpful to be specific about what you want reviewed. TS_SERVER\SYS2\COMMON\\\TS_SERVER\SYS2\USR\SFESSER\LAPIANTA.DOC I City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: 7\1 ?e,AeL. V.T-akty- COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999 Op APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind V PROJECT TITLE: LaPianta Rezone& Comp. Plan Amendment WORK ORDER NO: 78520 3,11LOCATION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres I BUILDING AREA(gross) N/A SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zoning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. ENVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemen of the Probable Probable More Element of the Probable Probable More Environment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation LandiShireline Use Utilities Animals Transportation Environmental Health Public Services Energy/Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. POLICY-RELATED COMMENTS C. CODE-RELATED COMMENTS We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where acditional information is needed to properly assess this proposal. tVe, / U,/3/79 Signature of Director or Authorized Representative Date DEVAPP Rev.10/93 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT: 71ve P f:(O n1 1 C71 COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999r APPLIC ANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lindp E PROJE::T TITLE: LaPianta Rezone & Comp. Plan Amendment WORK ORDER NO: 78520 a LOCATION: SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension APR i2 4 eyyy SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A l Pi`' -e 1. SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family Nith R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zoning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. ENVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemen'of the Probable Probable More Element of the Probable Probable More Environment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Sh)reline Use Utilities Animals Transportation Environmental Health Public Services Energy/Historic/Cultural Natural I?esouroes Preservation Airport Environment 10,000 Feet 14,000 Feet Q N0 kyry ci AJ B. POLICY-RELATED COMMENTS AAl1 ,, v/f C. CODE-RELATED COMMENTS We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where addition 7 information ii eeded to properly assess this proposal. 0 0Signatuof (rector or Authorized resentative Date DEVAPP Rev.10/993 City of r e:, on Department of Planning/Building/Public vvorks ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIENING DEPARTMENT: s COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind PROJECT TITLE: LaPianta Rezone& Comp. Plan Amendment WORK ORDER NO: 78520 LOCATION. SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres BUILDING AREA(gross): N/A SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zc ning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. EWVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemer t of the Probable Probable More Element of the Probable Probable More Environment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Sl oreline Use Utilities Animals Transportation Environ nental Health Public Services Energy?Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet 6z2ux 1 •-/i ek) oe_E A).—fu 2 S CY./ /10 c P 7tv7774:e ft=7 i23.o04 c% B. POLICY-RELATED COMMENTS a"V-A—\; yL_7LZ/7/'(." 77. /2e'd fit— /-& 2/ec: Te,66,24. gze_k • C. CDDE-RELATED COMMENTS 1-1-) 6 We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where additional information is needed to properly assess this proposal. 7/esy777SigndtureofDirectororAuthorizedRepresentativeDate DEVAPP Rev.10/93 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT:< x,,,yfa I COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind AE^N PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 r LOCATION: SE Quadrant of NE 3rd/NE 4th and Edmonds Ave. extension E(jin_ SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A ~ ;`-ovita lv SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zc Wing. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. ENVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element`of the Probable Probable More Element of the Probable Probable More Environment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Wafer _ Light/Glare Plants Recreation LancVS!oreline Use Utilities Animals Transportation Environmental Health Public Services Energy/Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. P:)LICY-RELATED COMMENTS C. CODE-RELATED COMMENTS Uqo GOW1 WI e"t/ ' We hava reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area where additional information is needed to properly assess this proposal. Nev /Va it 2-t/04,41 Signatui 4 of Director or Authorized Representative Date DEVAPP Rev.10/5 City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL 8 DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT vo—v 1 _` a C,L COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1 QF RFNTON APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca LindFtiFrt °>.rrt PROJECT TITLE: LaPianta Rezone&Comp. Plan Amendment WORK ORDER NO: 78520 APR. 2 2 199 LOCATION: SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A UILL01 1 4...A v SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zc ling The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. ENVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Element of the Probable Probable More Element of the Probable Probable More Enviror ment Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/St oreline Use Utilities Animals Transportation Environ-nenfat Health Public Services Energy/Historic/Cultural Natural Resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. POLICY-RELATED COMMENTS C. CODE-RELATED COMMENTS I\Jo CP* 141ea • We have reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or area where a iditional information is needed to properly assess this proposal. Ctq Signatu e of Director or Authorized Representative Date DEVAPP Rev.10/E City of Renton Department of Planning/Building/Public Works ENVIRONMENTAL & DEVELOPMENT APPLICATION REVIEW SHEET REVIEWING DEPARTMENT:6, ,wSt,,tC -lct'\ St=VI,t( et COMMENTS DUE: APRIL 30, 1999 APPLICATION NO: LUA-99-054,CPA,ECF DATE CIRCULATED: APRIL 19, 1999 APPLICANT: LaPianta Limited Partnership PROJECT MANAGER: Rebecca Lind OF RENTOp PROJECT TITLE: LaPianta Rezone& Comp. Plan Amendment WORK ORDER NO: 78520 APRLOCATION: SE Quadrant of NE 3`d/NE 4th and Edmonds Ave. extension SITE AREA: 96.2 acres I BUILDING AREA(gross): N/A 8U1Liliervu W V SUMMARY OF PROPOSAL: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options with R-10 zoning, and half of the property to Residential Planned Neighborhood with 14 zoning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. A. ENVIRONMENTAL IMPACT(e.g. Non-Code) COMMENTS Elemen'of the Probable Probable More Element of the Probable Probable More Environ,rent Minor Major Information Environment Minor Major Information Impacts Impacts Necessary Impacts Impacts Necessary Earth Housing Air Aesthetics Water Light/Glare Plants Recreation Land/Sh:rreline Use Utilities Animals Transportation Environmental Health Public Services Energy/Historic/Cultural Natural,resources Preservation Airport Environment 10,000 Feet 14,000 Feet B. POLICY-RELATED COMMENTS M /t.2_ C. CODE-RELATED COMMENTS 1/c>jv6 We haw reviewed this application with particular attention to those areas in which we have expertise and have identified areas of probable impact or areas where additi al information is needed to properly assess this proposal. Signature of Director or thorized Representative Date DEVAPP Rev.10/99 CITY OF RENTON DEVELOPMENT SERVICES DIVISION LIST OF SURROUNDING PROPERTY OWNERS within 300 feet of the subject site PROJECT NAME: La Pianta Comprehensive Plan Amendments and Rezone APPLICATION NO: LVw • 99 . 05} (2, E The following is a list of property owners within 300 feet of the subject site. The Development services Division will notify these individuals of the proposed development. SAME ADDRESS ASSESSOR'S PARCEL NUMBER See attached .sheet(s) . 0,0111 le fittttke . 0. , 1 tI 11 44rr Attach additional sheets, if necessary) 4. Continued) N, ME ADDRESS ASSESSOR'S PARCEL NUMBER 1 Applicant Certification I, i4V I D L. /44L ( to EN , hereby certify that the above list(s) of adjacent (pp,,,,, Print Name) tt L SA -„ owners and their addresses were obtained from: 4` Er. i City of Renton Technical Services Records :` ;••'° STAR 0I Title Company Records N King County Assessors Records n PUBLIC Signed Date .3 / FO'"-***"'a,,,,•, Applica t) F,wAcj ,‘‘s NOTARY ATTESTED: Subscribed and sworn before me, a Notary Public, in and for the State of Washington, residing at TCGCDf'f99) i4/1,— on the,3/ day of /lidliZ 4' 19 . Signed Notary Public) at#s f "+ .For City of.RentonUse * CERTIFICATION OF'MAILING I hereby certify that:notices of the proposed application were mailed to0.15-/ Olet....r, City Employee) ebiCh...l.i,StedPrOper..tY.:-ownpr„pR...::::::,...:......„. :. , ...... . „.„....,,....:::....... ..........‘........ i.it.7, .. .... .„„.., .., .... „ . , .. , . :Signed. ;: ; NOTARY ATTEST „ Subscribed and sworn before me, a Notary Public, in and for the State'of Washin ton residing at on the / t day of 2'# 19' Signed ...: listprop.doc REV 07/95 MARILYN KAMCHEFF 2 COMMISSION EXPIRES 6/29/99 R Sound Energy&Elec Puget T&E INVESTMENT INC ATLANTIC RICHFIELD COMPANY PO Box 90868 353 Vuemont Pl Ne PO Box 512485 Bellevue,WA 98009 Renton,WA 98056 Los Angeles,CA 90051 KING COUNTY Lp LaPianta KING COUNTY 500 4Th Ave PO Box 88050 500 K C Admin Bldg#A Seattle,WA 98104 Tukwila,WA 98138 Seattle,WA 98104 NOT AVAILABLE FROM COUNTY MT OLIVET CEMETERY Keith&Annette Demps Sr. 6205 24Th St Ne PO Box 547 2308 Ne 24Th St Tacoma,WA 98422 Renton,WA 98057 Renton,WA 98056 Lp LaPianta ANMAR CO RENTON THIRD AVE PROP LLC PO Box 88050 9125 IOTh Ave S PO Box 814 Tukwila,WA 98138 Seattle,WA 98108 Zillah,WA 98953 Sound Energy&Elec Puget ANMAR CO RAMAC INC PO Box 90868 9125 l OTh Ave S 20919 Se 34Th St Bellevue,WA 98009 Seattle,WA 98108 Issaquah,WA 98029 Seung Sik&Eunsil Paik Seung Sik&Eunsil Paik Phyllis Larue 2439 Se Maple Valley Hwy 2439 Se Maple Valley Hwy 2505 Maple Valley Hwy Renton,WA 98055 Renton,WA 98055 Renton,WA 98058 KING COUNTY KING COUNTY KING COUNTY 500 4Th Ave 500 4Th Ave 500 4Th Ave Seattle,WA 98104 Seattle,WA 98104 Seattle,WA 98104 KING COUNTY Portfolio Lp Essex STATE OF WASHINGTON 500 4Th Ave 777 S California Ave 2631 Ne 4Th St Seattle,WA 98104 Palo Alto,CA 94304 Renton,WA 98056 I lousing Authority Renton Lp LaPianta 4)70 Harrington Ave Ne PO Box 88050 Renton,WA 98056 Tukwila,WA 98138 TY rO NOTICE OF APPLICATION A Master Application has been flied and accepted with the Development Services Division of the City of Renton. The following briefly describes the application and the necessary Public Approvals. PROJECT NUMBERINAME. LUA.99-054,CPA,ECF,R I LaPlanta Limited Partnership Rezone and Comprehensive Plan Map and Test Amendment(CPA) PROJECT DESCRIPTION: Amend the Land Use Map to change approximately half of Nis progeny horn Residential Single Family with R-8 zoning to Residential OplwnsIRO)with R-I0 zoning.and half of the property 10 Resdential Planned NeionborhoodlRPN)with R.ta 40nng. The proposal also Includes changing land use pounce to allow senor stacked flats within the RPN designation. PROJECT LOCATION:SE Quadrant ONE S./NE a"and Edmonds Avenue Ealensan PUBLIC APPROVALS.Planning Commission Public Nearing and Recommendation,Coy Council Approval Comments on the above applicatan mast be submitted in wdtng to Rebecca Lind.Protect Manager,Strategic Planning mean 1055 South Grady Way.Renton,WA 98055.by 5.00 PM on May 04,1999. If you have Ruestans abet.,Bus proposal,or wish to be made a party of record and receive adduanal notification by mad,contact Mr.Dennison at(425) 430-6588.Anyone who submits wnflen comments will aatomatrally become a parry of record and will be notAgd of any decision on this protect PLEASE INCLUDE THE PROJECT NUMBER WHEN CALLING FOR PROPER FILE IDENTIFICATION DATE OF APPLICATION: March 31.1999 NOTICE OF COMPLETE APPLICATION: Apm 19.1999 DATE OF NOTICE OF APPLICATION: April 20,1999 rl ss M° z I R-101R-10 RM-1 R-9 RMH IL(Pl pp R-8 RMH 5 RC RC 1 /1 RCtP) I RC 01 NOIKapIJpC w•:euu• Nnsw RM wsi CERTIFICATION I, (jcv (eipA , hereby certify that copies of the above document were posted by me in , _ conspicuous places on or nearby the described property on pal GI ele Signed: ATTEST: Subcribed and sworn before me, a Nortary Public\ f__:rt6:-k,-,A, inhe State of Washington residing on the J.)Nh. day of 4--) e- er / r'/4 5 . Ct + MARILYN KAMMCHEFF COMMISSION EXPIRES 6/29/99 60.6 r WIC, D. 4.1* NTO NOTICE OF APPLICATION A Master Application has been filed and accepted with the Development Services Division of the City of Renton. The following briefly describes the application and the necessary Public Approvals. PROJECT NUMBER/NAME: LUA-99-054,CPA,ECF,R I LaPianta Limited Partnership Rezone and Comprehensive Plan Map and Text Amendment(CPA) PROJECT DESCRIPTION: Amend the Land Use Map to change approximately half of this property from Residential Single Family with R-8 zoning to Residential Options(RO) with R-10 zoning, and half of the property to Residential Planned Neighborhood(RPN) with R-14 zoning. The proposal also includes changing land use policies to allow senior stacked flats within the RPN designation. PROJECT LOCATION: SE Quadrant of NE 3rd/NE 4th and Edmonds Avenue Extension PUBLIC APPROVALS: Planning Commission Public Hearing and Recommendation,City Council Approval Comments on the above application must be submitted in writing to Rebecca Lind, Project Manager, Strategic Planning Division 1055 South Grady Way, Renton, WA 98055, by 5:00 PM on May 04, 1999. If you have questions about this proposal,or wish to be made a party of record and receive additional notification by mail, contact Mr. Dennison at(425) 430-6588. Anyone who submits written comments will automatically become a party of record and will be notified of any decision on this project. PLEASE INCLUDE THE PROJECT NUMBER WHEN CALLING FOR PROPER FILE IDENTIFICATION DATE OF APPLICATION: March 31,1999 NOTICE OF COMPLETE APPLICATION: April 19, 1999 DATE OF NOTICE OF APPLICATION: April 20, 1999 ES.9 TUN R5E W t/2 R_ Application 99-M-: R-R _ " NE 4lh St RB RM—I I .CA : co NE 3rA St. R-10 R-10 RM-11 NI R-8 .ILCP) RMH i" R-8 RMH RC RC OR • RC(P) pia RC 4 • R-8 OS•21 MN R5E W VZ i*Qa,)ZONING M FS NOTICEOF.DOC te "TM' u ' 16 T23N R5E W Sound Energy&Elec Puget T&E INVESTMENT INC ATLANTIC RICHFIELD COMPANY PO Box 90868 353 Vuemont P1 Ne PO Box 512485 Bellevue,WA 98009 Renton,WA 98056 Los Angeles,CA 90051 KING COUNTY Lp LaPianta KING COUNTY 500 4Th Ave PO Box 88050 500 K C Admin Bldg#A Seattle,WA 98104 Tukwila,WA 98138 Seattle,WA 98104 NOT AVAILABLE FROM COUNTY MT OLIVET CEMETERY Keith&Annette Demps Sr. 6205 24Th St Ne PO Box 547 2308 Ne 24Th St Tacoma,WA 98422 Renton,WA 98057 Renton,WA 98056 Lp LaPianta ANMAR CO RENTON THIRD AVE PROP LLC PO Box 88050 9125 l OTh Ave S PO Box 814 Tukwila,WA 98138 Seattle,WA 98108 Zillah,WA 98953 Sound Ene„,_ &Elec Puget A I. •R O RAMAC INC PO :• ''•868 9125 '"' •ve S 20919 Se 34Th St Belle 4e, ' 98009 Sea, e,WA 98108 Issaquah,WA 98029 Seung Sik&Eutlsil Paik Seun: Sik : unsil Paik Phyllis Lame 2439 Se Maple Valley Hwy 2439 - ,4 •ple Valley Hwy 2505 Maple Valley Hwy Renton,WA 98055 Renton, A ':055 Renton,WA 98058 KING C"i TY KING C I TY K CO TY 50' ._ P/•ve 500 ' - Ave 500 4Th Seatt , • 98104 Sea , ,W• '8104 Seattle A 98104 KING CO': Portfolio Lp Essex STATE OF WASHINGTON 500 "s Ave 777 S California Ave 2631 Ne 4Th St Seatt -, ' - 98104 Palo Alto,CA 94304 Renton,WA 98056 Housing Authority Renton Lp aPi to 970 Harrington Ave Ne PO B 88050 Renton,WA 98056 Tukw a, A 98138 4,4 _gq _ 0 5 q Li_ 021)/4- i--k CITY ( F RENTON Planning/Building/Public Works Department Greggimmerman P.E.,AdministratorJesseTanner,Mayor gg April 20, 1999 Ms. Ann Nichols La Pianta Limited Partnership PO Box 88028 Tukwila, WA 98138 SUBJECT: La Pianta Rezone (R) and Comprehensive Plan Amendment (CPA) Project No. LUA-99-054,CPA,R,ECF Dear Ms. Nichols: The Development Planning Section of the City of Renton has determined that the subject application is complete according to submittal requirements and, therefore, is accepted for review. It is tentatively scheduled for consideration by the Environmental Review Committee on May 11, 1999. Prior to that review, you will be notified if any additional information is required to continue processing your application. Please contact me, at (425)430-6588, if you have any questions. Sincerely, 6111-0 Rebecca Lind Project Manager ACCEPT 1055 South Grady Way- Renton, Washington 98055 CITY OF RENTON DEVELOPMENT SERVICES DIVISION LAND .1SE PERMITVii05 MASTER AP1.iATiCfl kli- ' ... .... . r, PROPERTY OWNER(S) PROJECT INFORMATION Note If there is more than one legal owner please attach an additional notarized notarized Master Application for each owner. PROJECT OR DEVELOPMENT NAME: quell"4 i NAME: I,a Pianta Limited Partnership La Pianta Comprehensive Plan:Amendments and Rezone PROPERTY/PROJECT ADDRESS(S)/LOCATION: ADDRESS: P.O. Box 88028 Southeast quadrant of NE 3rd/NE 4th and Edmonds Avenue Extension CITY: r2L1kWila Z(P: 98138 KING COUNTY ASSESSOR'S ACCOUNT NUMBER(S): 162305-9006-05 172305-9171 -03 162305-9007-04 162305-9009-02 162305-9061 -07 162305-9010-09 TELEPHONE NUMBER: (206) 575-2000 EXISTING LAND USE(S): VACANT APPI:ICANT (if other than'owner) PROPOSED LAND USES: NAME: SAME AS OWNER Single-family (attached and detached) and multi-family COMPANY (if applicable): EXISTING COMPREHENSIVE PLAN MAP DESIGNATION: Residential Single Family (RS) ADDRESS: PROPOSED COMPREHENSIVE PLAN MAP DESIGNATION (if applicab' Residet-ttial Opticns (It)) did R si dE ti al Pled Neigi -m (HEN) (Alsa, pxpe cl REN did R-14 CITY: ZIP: EXISTING ZONING: tPXt arts) Residential Manufactured Homes (RMH) TELEPHONE NUMBER: PROPOSED ZONING (if applicable): Residential-10 DU/AC (R-10) and CONTACT. PERSON Residential-14 DU/M*BtcE NT SITE AREA (SQ. FT. OR ACREAGE): C17Y OF RENL1 N.JING NAME:Ann Nichols 96.2 acres +/- MAR 31 1999 COMPANY (if applicable): PROJECT VALUE: RECEIVED La Pianta Limited Partnership N/A ADDRESS:P.O. Box 88028 IS THE SITE LOCATED IN THE AQUIFER PROTECTION AREA? Yes, partially in APA Zone 1 and partially in APA Zone 2. CITY: TukWila ZIP: 98138 IS THE SITE LOCATED IN ANY OTHER TYPE OF ENVIRONMENTALL SENSITIVE AREA? Not to applicant's knowledge. TELEPHONE NUMBER: (206) 575-2000 LEGAL;:DE? PTION OF PROPERTY (Afta. h : rate sheet "if necessary). r . ice)- III ;RCELS' 1 THROUGH 4, 9 AND 10 OF CITY OF RENTON LOT LINE 1 'REIN FILE NUMBER LUA-95-200-LLA, AS RECORDED IN BOOK 108 I I.' "151IVURVEYS AT PAGES 276, 276A AND 276B, UNDER KING COUNTY et RECORDING NUMBER 9604239004. TYPE.OI= APPLICATION & FEES Check all application;types that apply -City staff will ,determine.:fees ANNEXATION SUBDIVISION: x COMP. PLAN AMENDMENT x REZONE LOT LINE ADJUSTMENT SPECIAL PERMIT SHORT PLAT TEMPORARY PERMIT TENTATIVE PLAT CONDITIONAL USE PERMIT PRELIMINARY PLAT SITE PLAN APPROVAL FINAL PLAT GRADE & FILL PERMIT NO. CU. YDS: PLANNED UNIT DEVELOPMENT: VARIANCE FROM SECTION:PRELIMINARY WAIVER T FINAL WETLAND PERMIT ROUTINE VEGETATION MOBILE HOME PARKS: MANAGEMENT PERMIT BINDING SITE PLAN SHORELINE REVIEWS: SUBSTANTIAL DEVELOPMENT $ CONDITIONAL USE VARIANCE EXEMPTION No Charge x ENVIRONMENTAL REVIEW t' REVISION AFFIDAVIT OF::OWNERSHIP I, (Print Name) M.A. Segale declare that I am (please check one)_the owner of the property involved in this application, xthe authorized representative to act for the property owner (please attach proof of authorization), and that the foregoing statements and answers herein contained and the information herewith submitted are in all respects true and correct to the best of my knowledge and belie````%xxv , LA PIANTA LIMITED PARTNERSHIP, a A.A. P asl1 Washington limited partnership LPN......... ! iiif' ATTEST: Subscribed and sworn to befo=`e .41ej190/Ifee..irrpngo By: Metro Land Development,Inc. , a f° thle s o4 residing 10 4 in tarn its Coal ParU r ayh 1 on the d! fN Rj' '9 a r Mai 7s i .0 ... H 3 0 o By: • ,v y ...a 44 M.A. Segale, resident Øureofic) JaryPubli` 4 11 OF section to be.completed•by City:Staff CP City File Number _ 7f .. A AAD :BSP ::CAP.S CAP U A CU H ECLLA ;: MHP FPUD 'FP P VMP SA A SA H SHPL A SHPL H. .SP. _SM SME TP: V A.. V B .V H TOTAL FEES '$ 5)TOTAL POSTAGE PROVIDED. $ rt MASTERAP.DOC REVISED 8/97 APR 2 elf) (4\ Project Narrative 4C1f)j‘ IV Justification for Comprehensive Plan Amendment, Rezone Project Name: La Pianta Comprehensive Plan Amendments and Rezone Project Location: South side of NE 3rd/NE 4th Street east of Mt. Olivet Cemetery, Renton, WA Current Use: Vacant Land (mined out gravel pit) Current Zoning: RMH — Residential Manufactured Homes Proposed Zoning: R-14/R-10 Proposed Use:Mixed Use Residential Development with a small neighborhood commercial use. Proposed by: La Pianta Limited Partnership ("La Pianta") 1. Requested Change to Comprehensive Plan and/or Zoning Map La Pianta hereby requests comprehensive plan land use map amendments and corresponding rezone on several adjacent parcels of it's land located on the south side of NE 3rd/NE 4' Streets at the intersection with Edmonds Avenue NE in Renton, WA. La Pianta is making this formal application, along with all supporting and requested documents listed by the City of Renton in it's guide to Comprehensive Plan Amendments. The subject property is currently zoned RMH — Residential Manufactured Homes, a zoning classification that does not allow development of a mixed use community. La Pianta proposes to change the site's zoning so that a portion would be R-14 and the balance would be R-10, similar to the land use designation for some of the properties surrounding the subject property. La Pianta contemplates ultimate development of a mixed use community on the subject property with four villages that would feature age-restricted townhouses/flats, alley-loaded and traditional townhouses, as well as alley-loaded and traditional single family homes. 2. Size and Location of Site The subject property is located on the south side of NE 3rd/NE 4th Streets, east of Mt. Olivet Cemetery, west of the King County Shops and north of the Maple Valley Highway in Renton. The subject property consists of six contiguous parcels owned by La Pianta totaling 96 acres in size. The south edge of these parcels has an irregular shape that follows the top of slope above the Maple Valley Highway. DEVELOPMENT PLANNING CITY OF RENTON 99015Proj Nar.doc, 4/2/99, page 1 APR 0 4 1999 RECEIVED 3. Current Use of Site and Any Existing Improvements The site is currently vacant after having been previously used as a gravel mine. Improvements for the southerly extension of Edmonds Avenue into the property have recently been constructed. Significant grading of portions of the site has occurred as part of a previously approved manufactured housing project and in relation to the City's sewer interceptor line that crosses the property. There are currently no structures on the site. 4. Special Site Features Special site features include the site's location, size and topography. The location is a prominent one in the Renton Highlands and would be attractive to potential homeowners with its easy access to downtown Renton and the nearby commercial uses along NE 4th Street. The site's relatively large size would allow for the development of a quality mixed use neighborhood with single family homes, townhouses, senior flats, a small neighborhood commercial facility and open space, both active and passive. The topography would allow a new neighborhood to be built below NE 3rd/NE 4'h Streets with little visual impact, even of the proposed senior flats. Further, the site's topography and southward orientation provides opportunities for substantial southerly views. 5. Location of Existing Structures This site is currently vacant with no existing structures. 6. Special responses to the following Decision Criteria: 1. The CPA/Rezone bears a substantial relation to the public health, safety or welfare. The requested Comprehensive Plan Amendments and rezone, if granted, would allow for the provision of a wide variety of housing to address the needs of area residents, would provide substantial opportunities for home ownership, and would increase the City's tax base. 99015Proj Nar.doc, 4/2/99, page 2 2. The CPA/Rezone addresses changing circumstances or the needs of the City as a Whole. The City of Renton as a whole is experiencing an increase in demand for both residential real estate and commercial space as a result of a strong local employment base. This proposal will allow for a variety of housing opportunities to meet the varied needs of the housing market and provide housing opportunities for employees of local businesses. 3. The CPA/Rezone is compatible with the provisions of the Comprehensive Plan or other policies or goals of the City The requested CPA's and rezone are compatible with the Comprehensive Plan as it furthers the goals and policies of the plan to increase the variety of housing and channel growth into the City's urban area. Please refer to the following section addressing the policies. This location is ideal for a mixed use community in view of it's easy access to downtown Renton and the NE 3rd/NE 4`h Street corridor. 4. The CPA/Rezone is compatible with and not materially detrimental to adjacent Land uses and surrounding neighborhoods. See answer #3 above. The adjacent land owners and residents will no longer have to look at the undeveloped property in its current state and the neighborhood will be improved, both aesthetically and economically, as a result of the proposed project. The mixed use proposal, especially with the topography, is very compatible with all the surrounding uses including the proposed plat of La Colina to the west. 5. The CPA/Rezone will not result in development which will adversely impact community facilities, including but not limited to utilities, transportation, parks or schools The sites current RS Comprehensive Plan land use designation allows for development of the parcels as R-8 (or 8 dwellings per acre). La Pianta's proposal calls for a slight increase in density yet, with the variety of housing types, including attached homes and senior flats, the impacts on utilities, transportation, parks, or schools will be very similar to the impacts of R-8 development. No adverse impacts on such community facilities is expected. 99015Proj Nar.doc, 4/2/99, page 3 6. The subject property is suitable for development in general conformance with zoning standards under the proposed zoning classification. With the site's previous grading and the installation of storm drainage facilities, the site is very well-suited to development under the proposed R- 10 and R-14 zoning classifications. The R-10 classification allows for both attached and detached housing yet the proposal for the portion of the site proposed R-10 envisions all detached homes ranging from executive lots to alley-loaded homes. The R-14 classification allows for the envisioned attached homes and a small commercial area which will serve both the subject property and the nearby La Colina subdivision, and with the proposed text change to the R-14 code, this classification would also allow the provision of a multi-story senior age-restricted building envisioned in the northeast portion of the site. Development densities in both the R-10 and R-14 zones will most likely be near the minimum densities called for in the City's code. The proposed Comprehensive Plan Amendments to Residential Planned Neighborhood (RPN) and Residential Options (RO) is consistent with the City's goals and policies, as noted in the following: General Residential Policies: LU-11 The proposal will allow development of vacant land in environmentally suitable land on the hills and plateaus surrounding downtown Renton. Residential-Types LU-15 The proposal will allow a mix of housing types including large lot and small lot single family development, and residential mixed use development. LU-16.1 The proposal will allow a mix of single family and small scale multi-family housing types designed to look like single family development with ground related entries, i.e. duplex, triplex, and fourplex. The text change proposed for the R-14 zone will allow a mix of a higher density multi-family senior oriented building and townhouses. Residential Options and Residential Planned Neighborhood General Policies LU-41 The proposal will provide opportunity for small-lot single family detached homes and townhouses that meet the R-10 density standards. 99015Proj Nar.doc, 4/2/99, page 4 LU-42 The proposal will provide opportunity for a range of lot sizes. LU-43 The applicant envisions a central point at the entry to the contemplated new neighborhood on this site with passive open space facilities and a small neighborhood commercial use. LU-45 The site is conducive to a flexible grid street system generally of the type that the City has previously approved for the earlier manufactured housing project proposal. Residential Options Policies LU-50 The proposal meets the criteria for the Residential Option Designation through the following: a) the adjacent parcel to the northeast is currently zoned R- 10, b) the development proposal that La Pianta envisions for the proposed R-10 portion of the site would involve a mix of traditional and alley-loaded single family detached homes, similar in density to the manufactured housing project previously approved, c) the subject parcels are currently vacant, d) few new roads or major utility upgrades will be required since a City sanitary sewer interceptor has already been constructed through the site and a southerly extension of Edmonds Avenue NE has already been installed, and e) the site is adjacent to a City mapped Institutional Center. LU-51 and LU-54 The envisioned development on the proposed R-10 portion of the site would involve a net density between 7 to 10 homes per acre, ranging from small alley-loaded homes to larger executive lots. Residential Planned Neighborhood Policies LU-57 The proposed RPN portion of the site meets the criteria for RPN designation by a) being located adjacent to NE 3`d/4th Street, a major arterial, b) being adjacent to the City mapped Institutional Center and the employment corridor along NE 4th Street, c) being larger than 20 acres in size, d) being buffered from other single family neighborhoods (the site will be separated from the La Colina subdivision to the west by power line easements) and is compatible with the other surrounding uses due to the site's topography (which is generally well below that of adjacent areas) and e) by having achievable potential for development within the density and unit type range called for in the Comprehensive Plan and Zoning Code. 99015Proj Nar.doc, 4/2/99, page 5 4 LU-58 The envisioned development within the proposed R-14 portion of the site would include attached single family residences to senior oriented (age restricted) townhouses and flats, as well as the small commercial use. A text amendment to LU-61 is requested to permit senior flats within the RPN designation. (See the accompanying memorandum from attorney David L. Halinen. 99015Proj Nar.doc, 4/2/99,page 6 A. BACKGROUND 1. Name of proposed project, if applicable: 9) 14 La Pianta Comprehensive Plan Amendments and Rezone (a non project action)ialt,As°( 11 2. Name of applicant: r 61; La Pianta Limited Partnership 3. Address and phone number of applicant and contact person: Applicant: Contact Person: Attn:Ann Nichols Craig J. Krueger c/o Segale Business Park C/O Dodds Engineers, Inc. (DEI) P 0 Box 88050 4205 - 148th Ave. N.E., Suite 200 Tukwila, WA 98138 Bellevue, WA 98007 206) 575-2000 425) 885-7877 4. Date checklist prepared: March 31, 1999 5. Agency requesting checklist: City of Renton Planning Department 6. Proposed timing or schedule (including phasing, if applicable): The proposed Comprehensive Plan Amendments and Rezone are anticipated to be processed by the City by Fall 1999. Development is anticipated to start in the Spring of 2000 dependant on the approval of the CPA and rezone application as well as subsequent site plan and preliminary plat applications. 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. Development of the subject property consistent with the proposed Comprehensive Plan Amendments and Rezone is contemplated in future years but is not part of this proposal. 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. The City of Renton has recDen prreparedMENT PnLJ{ the revised City of Renton comprehensive and zoning plans. CCCITYPOF RENTON APR 0 4 1999 RECEIVED 99015 SEPA.doc; 04/02/99; Page: 2 9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. No. 10. List any government approvals or permits that will be needed for your proposal, if known. City Council approval of the proposed Comprehensive Plan Amendments and Rezone. 11. Give a brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. (Lead agencies may modify this form to include additional specific information on project description.) The proposal is to amend the Comprehensive Plan Land Use Map designation of the approximately 96 acre subject property from Residential Planned Neighborhood (PNR) in part and Residential Options (RO) in part and correspondingly rezone the property to R-14 and R-10. 12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. The site is located north of Maple Valley Highway, south of NE 3rd/NE 4' Street, east of Mt. Olivet cemetery and west of the King County shops in the City of Renton. A property map is attached hereto and incorporated by reference. 13. Does the proposal lie with an area designated on the City's Comprehensive Land Use Policy Plan map as environmentally sensitive? Yes, the proposed project is partially in Aquifer Protection Area Zone 1 and partially in Aquifer Protection Zone 2. The RC-zoned area south of the site is designated Greenbelt. 99015 SEPA.doc;04/02/99; Page: 3 EVALUATION FOR AGENCY USE ONLY B. ENVIRONMENTAL ELEMENTS 1.. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous other The portion of the site where most of the future development on the site is expected is gent/ sloping, while the perimeter of the site contains steeper slopes. b. What is the steepest slope on the site (approximate percent slope)? The steepest slope is ± 67%. c. What general types of soils are found on the site (for example, clay, sand, gravel, peat. muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. Sand and gravel, no agricultural soils. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so. describe. No, the stability of the southern slope is addressed in the Geo Engineers report dated March 7. 1994, a copy of which has been attached as a part of the manufactured housing proposa, previously approved by the City for the subject property. e. Describe the purpose, type, and approximate quantities of any filling or grading proposed Indicate source of fill. None proposed at this time. Application is for CPA and rezone only. f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. N/A g. About what percent of the site will be covered with impervious surfaces after projec construction (for example, asphalt or buildings)? N/A 99015 SEPA.doc;04/02/99; Page:4 h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: N/A 2. Air a. What types of emissions to the air would result from the proposal (i.e., dust, automobile. odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. Unknown at this time. Application is for CPA and rezone only. b. Are there any off-site sources of emissions or odor that may affect your proposal? If so. generally describe. No. c. Proposed measures to reduce or control emissions or other impacts to air, if any: None proposed at this time. 3. Water a. Surface: 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. Storm water retention and silt control structures and other man-made facilities only. 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. Not applicable. 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. Not applicable. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities if known. Not applicable. 5) Does the proposal lie within a 100-year floodplain? If so, note location on the site plan. No. 99015 SEPA.doc; 04/02/99; Page: 5 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. No. b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities if known. N/A 2) Describe waste material that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage: industrial, containing the following chemicals....; agricultural; etc.). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. N/A c. Water Runoff(including storm water): 1) Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. N/A 2) Could waste materials enter ground or surface waters? If so, generally describe. N/A d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: None proposed at this time. Storm ponds have already been installed. 4. Plants a. Check or underline types of vegetation found on the site: X deciduous tree: alder, maple, aspen, other: X evergreen tree: fir, cedar, pine, other: X shrubs grass pasture wet soil plants: cattail,buttercup, bullrush, skunk cabbage, other water plants: water lily, eelgrass, milfoil, other: other types of vegetation: b. What kind and amount of vegetation will be removed or altered? Trees and shrubs have been removed as part of the clearing and grading of the site associate( with the previously approved manufactured housing project and previously conducted grave mining of the site. 99015 SEPA.doc;04/02/99; Page: 6 c. List threatened or endangered species known to be on or near the site. None. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: N/A (Note: The sloped areas along the perimeter of the site affected by grading have been hydroseeded.). 5.. Animals a. Underline any birds and animals which have been observed on or near the site or are known to be on or near the site: birds: hawk, heron, eagle, songbirds, other: crows and miscellaneous small birds mammals: deer, bear, elk, beaver, other: squirrels, chipmunks, raccoons fish: bass, salmon, trout, herring, shellfish, other: None b. List any threatened or endangered species known to be on or near the site. None. c. Is the site part of a migration route? If so, explain. Unknown. d. Proposed measures to preserve or enhance wildlife, if any: N/A 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating. manufacturing, etc. Unknown at this time. Application is for CPA and rezone only. b. Would your project affect the potential use of solar energy by adjacent properties? If so. generally describe. No. c. What kinds of energy conservation features are included in the plans of this proposal: Lisi other proposed measures to reduce or control energy impacts, if any: None. Application is for CPA and rezone only. 99015 SEPA.doc; 04/02/99; Page: 7 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. No. 1) Describe special emergency services that might be required. None 2) Proposed measures to reduce or control environmental health hazards, if any: None. b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? None. 2) What types and levels of noise would be created by or associated with the project on a short-term or a long-term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. Unknown at this time. Application is for CPA and rezone only. 3) Proposed measures to reduce or control noise impacts, if any: N/A 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? The site is vacant, graded for manufactured housing project. The current use of the adjacent properties is as follows; Cemetery, King County Transfer station and shops, manufactured home park and multi famih residential. b. Has the site been used for agriculture? If so, describe. No. 99015 SEPA.doc;04/02/99; Page: 8 c. Describe any structures on the site. None. d. Will any structures be demolished? If so, what? None. e. What is the current zoning classification of the site? The current zoning is RMH—Residential Manufactured Homes. f. What is the current comprehensive plan designation of the site? SF"—Single family. g. If applicable, what is the current shoreline master program designation of the site? Not applicable. h. Has any part of the site been classified as an "environmentally sensitive" area? If so. specify. Yes, the proposed project is partially in Aquifer Protection Area Zone 1 and partially in Aquifef Protection Area Zone 2. (The RC-zoned portion south of the site is designated Greenbelt.) i. Approximately how many people would reside or work in the completed project? Unknown at this time. Application is for CPA and rezone only. j. Approximately how many people would the completed project displace? None. k. Proposed measures to avoid or reduce displacement impacts, if any: Not applicable. I. Proposed measures to ensure the proposal is compatible with existing and projected Ian( uses and plans, if any: The proposal is consistent with current City of Renton comprehensive plan goals and policies. 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle or low-income housing. Unknown at this time. Application is for CPA and rezone only. 99015 SEPA.doc; 04/02/99; Page: 9 b. Approximately how many units, if any, would be eliminated? Indicate whether high. middle, or low-income housing. None. c. Proposed measures to reduce or control housing impacts, if any: Not applicable. 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? Unknown at this time. Application is for CPA and rezone only. b. What views in the immediate vicinity would be altered or obstructed? None. c. Proposed measures to reduce or control aesthetic impacts, if any: None required at this time. 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur. Unknown at this time. Application is for CPA and rezone only. b. Could light or glare from the finished project be a safety hazard or interfere with views? N/A. c. What existing off-site sources of light or glare may affect your proposal? None. d. Proposed measures to reduce or control light and glare impacts, if any: N/A. 12. Recreation a. What designated and informal recreational opportunities are in the immediate vicinity? Liberty Park, Cedar River Park, Windsor Hill Park and the Maplewood golf course are all arc located within 1 mile of the project. 99015 SEPA.doc; 04/02/99; Page: 10 b. Would the proposed project displace any existing recreational uses? If so, describe. No. c. Proposed measures to reduce or control impacts on recreation, including recreational opportunities to be provided by the project or applicant, if any? Unknown at this time. Application is for CPA and rezone only. 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe. No. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, o cultural importance known to be on or next to the site. None. c. Proposed measures to reduce or control impacts, if any: Not applicable. 14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any. Primary access to the site would be provided by the southward extension of Edmonds Avenue NI from NE 3rd/NE 4th Street, which extension has recently been constructed. There is an existing traffic signal at the intersection of NE 3rd/NE 4th Street and Edmonds Avenue NE. b. Is the site currently served by public transit? If not, what is the approximate distance t( the nearest transit stop? Yes, there is public transit service on NE 3rd/NE 4th Street. The nearest bus stop is 100 feet fron the intersection of NE 3rd/NE 4th Street and Edmonds Avenue NE. c. How many parking spaces would the completed project have? How many would th( project eliminate? Unknown at this time. Application is for CPA and rezone only. d. Will the proposal require any new roads or streets, or improvements to existing roads of streets, not including driveways? If so, generally describe (indicate whether public o private). Unknown at this time. Application is for CPA and rezone only. 99015 SEPA.doc;04/02/99; Page: 11 e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. No. f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. Unknown at this time. Application is for CPA and rezone only. g. Proposed measures to reduce or control transportation impacts, if any: Unknown at this time. Application is for CPA and rezone only. 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. Unknown at this time. Application is for CPA and rezone only. b. Proposed measures to reduce or control direct impacts on public services, if any. Unknown at this time. Application is for CPA and rezone only. 16. Utilities a. Underline utilities currently available at the site: electricity, natural gas, water refuse service, telephone, sanitary sewer, septic system, other. All utilities are available to the site through a proper extension of services. Extension o) services will be the developers'responsibility. b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. Electricity will be provided by Puget Sound Energy Natural Gas will be provided by Puget Sound Energy Water Service will be provided by the City of Renton Sanitary Sewer will be provided by The City of Renton Telephone Service will be provided by US West C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the leap agency is relying on them to make its decision. Signature: Date Submitted: i q'j Craig er 99015 SEPA.doc;04/02/99; Page: 12 D. SUPPLEMENTAL SHEET FOR NONPROJECT ACTIONS Do not use this sheet for project actions). Non-project actions are those that do not include a specific project. A non-project action may be rezone, annexation, or amendments to ordinances. For nonproject actions, the references in the checklist to the words "project," "applicant," and property or site" should be read as "proposal," "proposer," and "affected geographic area,' respectively. Because these questions are very general, it may be helpful to read them in conjunction with the list o the elements of the environment. When answering these questions, be aware of the extent of the proposal, or the types of activities likely to result from the proposal that would affect the item at a greater intensity or at a faster rate than i the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposal be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? The proposed Comprehensive Plan designations (RPN and RO) and zoning (R-14 and R-10) are very similar to the existing Comprehensive Plan designation (RS) and zoning(RMH) and will not significantly increase any discharge to water, emissions to air or production of noise. Uses permitted under the proposed categoric., will not produce, store or release toxic or hazardous substances. Proposed measures to avoid or reduce such increases are: None proposed since Comprehensive Plan Amendments and Rezone will ultimately result in similar uses to those previously studied and approved by the City for the subject property. 2. How would the proposal be likely to affect plants, animals, fish, or marine life? The site has already been mined and graded and storm drainage/water quality facilities have already been installed. The proposed CPA and rezone will not further affect plants, animals or fish. Proposed measures to protect or conserve plants, animals, fish, or marine life are: When development of the site ultimately occurs pursuant to the proposed zoning, erosion control, water quality and detention facilities will be required per City codes. 3. How would the proposal be likely to deplete energy or natural resources? Future development of the site pursuant to the proposed zoning will have approximately the same impact on energy and natural resources as allowed under the current Comprehensive Plan designation and zoning category. Proposed measures to protect or conserve energy and natural resources are: None required beyond normal City codes. 99015 SEPA.doc;04/02/99; Page: 13 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitat, historic or cultural sites, wetlands, floodplains, or prime farmlands? There are no such environmentally sensitive areas on the site at this time. Proposed measures to protect such resources or to avoid or reduce impacts are: None required or proposed. 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? The proposed Comprehensive Plan designations and proposed zones are very similar to the existing ones. No significant affect upon land and shoreline use is anticipated. Proposed measures to avoid or reduce shoreline and land use impacts are: A maximum residential unit yield will be established for the site so that such impacts will be similar to the current designations for the property. 6. How would the proposal be likely to increase demands on transportation or public services and utilities? The proposal will be very similar in scale to that envisioned by the City in adopting the current Comprehensive Plan and Zoning designations. There will be no significant increase in demand for these services. Proposed measures to reduce or respond to such demand(s) are: A maximum residential unit yield will be established for the site so that such impacts will be similar to the current designations for the property. 7. Identify, if possible, whether the proposal may conflict with local, state, or federal laws or requirements for the protection of the environment. The proposal will not conflict with local, state or federal laws or requirements for the protection of the environment. 99015 SEPA.doc; 04/02/99; Page: 14 ei LITIGATION / TRUSTEE'S SALE IssuEo BY CONTRACT FORFEITURE / GUARANTEE iTRANSNATIONTITLEINSURANCECOMPANY Transnation GUARANTEE NUMBER M 3b -(3 b E3 SUBJECT TO THE EXCLUSIONS FROM COVERAGE, THE LIMITS OF LIABILITY AND OTHER PROVISIONS OF THE CONDITIONS AND STIPULATIONS HERETO ANNEXED AND MADE A PART OF THIS GUARANTEE, TRANSNATION TITLE INSURANCE COMPANY, a corporation, herein called the Company, Guarantees the Assured against loss, not exceeding the liability amount stated in Schedule A, which the Assured shall sustain by reason of any incorrectness in the assurance which the Company hereby gives that, according to the public records, on the Date of Guarantee stated in Schedule A, the title to the herein described estate or interest was vested in the vestee named, subject to the matters shown as Exceptions in Schedule B, which Exceptions are not necessarily shown in the order of their priority. Et.OP 1YC CNT OF PC,, M FNTQN,•'NG AR3j 1999 E- In Witness Whereof, TRANSNATION TITLE INSURANCE COMPANY has caused this policy I_ to be signed and sealed as of the Date of Policy shown in Schedule A, the policy to become valid when countersigned by an authorized signatory. TRANSNATION TITLE INSURANCE COMPANY ovE iNS/,p 0 Q C0lI OR,t) r Attest: x M to ; By: SEPT j991 Secretary S Chairman and Chief Executive Officer Face Page-Litigation/Trustee's Sale/Contract Forfeiture Guarantee Form 1110-10 Valid only if Schedules A and B are attached. ORIGINAL LITIGATION/TR 'EE'S SALE/ CONTRACT FORE..__ URE/GUARANTEE INFORMATION FOR THE ASSURED 1.This Guarantee is restricted to the use of the Assured solely for the purpose of providing information to facilitate the commencement of a suit at law, the forfeiture of a real estate contract pursuant to RCW 61.30, or foreclosure pursuant to RCW 61.24 of a deed of trust described in Schedule B, affecting the land described in Schedule A. The Company shall have no liability for any reliance hereon except for the purpose for which this Guarantee is issued. This Guarantee is not a commitment nor an obligation by the Company to issue any policy or policies of title insurance insuring said land and it is not to be used as a basis for closing any transaction affecting title to said land. 2.Upon request made WITHIN 60 DAYS from the effective date of this Guarantee, the Company will extend the effective date of this Guarantee by endorsement to include the filing of any complaint and recording of Notice of Lis Pendens, recording of Notice of Intent to Forfeit Real Estate Contract, or recording of Notice of Trustee's Sale. Such an endorsement will show as additional exceptions, and therefore exclude from coverage, those matters attaching subsequent to the effective date of the Guarantee but prior to the issuance of the endorsement. 3.Upon request, on the 30th day preceding the date set for the forfeiture of trustee's sale or real estate contract, the Company will issue an endorsement identifying notices of federal tax liens filed in the public records, if any, affecting the land described in Schedule A. THE RESPONSIBILITY, HOWEVER, FOR DETERMINING THE 30TH DAY BEFORE THE SALE OR FORFEITURE, AND FOR MAKING THE REQUEST ON THAT SAME DAY, IS BORNE BY THE ASSURED. 4.The Company may, BUT IS NOT OBLIGATED TO, issue additional endorsements extending the effective date of the Guarantee at the request of the Assured. The fee for such endorsements will be charged according to the Company's filed Rate Schedule for such endorsements.The Company will not, and accepts no obligation to, issue an endorsement extending the effective date to, or beyond, the date of any sale of the premises, recordation of a declaration of forfeiture, trustee's sale or deed in lieu of foreclosure or forfeiture. Insurance may be provided following sale or forfeiture according to the Company's filed Rate Schedule. 5.Attention is called to Soldiers' and Sailors' Civil Relief Act of 1940 and amendments thereto and the Military Reservist Relief Act of 1991 (Sec. 800 to 810, Military and Veterans Code) which contain inhibitions against the forfeiture of land under a real estate contract or sale of land under a deed of trust if the owner is entitled to the benefits of said Acts. 6.Attention is called to the Federal Tax Lien Act of 1966 (Public Law 89-719) and amendments thereto which, among other things, provides for the giving of written notice of sale or forfeiture in a specified manner to the Secretary of the Treasury or his delegate as a requirement for the discharge or divestment of a federal tax lien in a non-judicial sale or forfeiture, and establishes with respect to such lien a right in the United States to redeem the property within a period of 120 days from the date of any such sale or forfeiture. 7.No guarantee is given nor liability assumed with respect to the identity of any party named or referred to in Schedule B or with respect to the validity, legal effect or priority of any matter shown therein. B 1110-10 TRANSNATION TITLE INSURANCE COMPANY 14450 N.E. 29TH PLACE BELLEVUE, WA 98007 HALINEN LAW OFFICES, P.S. COUNTERSIGNED: 2115 N 30TH ST, #102 TACOMA, WA 98403 Attn: DAVID HALINEN By: 1j-- 425) 646-8589/1-800-441-770 JOHN W. JONES, MARK S . NIKLASON CLAUDIA D. RELLIER or J. JAY PUGH FAX # (425) 646-8593) Order No. 867896 Liability: 320 . 0C Premium:320 . 0C Customer No.Tax:27 . 52 Total : 347 . 52 SECOND SUBDIVISION GUARANTEE 1 .Name of Assured: HALINEN LAW OFFICES, P.S . and LA PIANTA LIMITED PARTNERSHIP 2 . Date of Guarantee : March 26, 1999 at 8 : 00 A.M. THE ASSURANCES REFERRED TO ON THE FACE PAGE HEREOF ARE : That according to those public records which, under the recording laws, impart constructive notice of matters affecting title to the following descrLbed land: See "LEGAL DESCRIPTION: " The estate or interest in the land which is covered by this guarantee is : Fee Simple Title to the estate or interest in the land is vested in: LA PIANTA LIMITED PARTNERSHIP, A WASHINGTON LIMITED PARTNERSHIP subject to the Exceptions shown below, which are not necessarily shown in order of their priority. EXCEPTIONS : 1 . Taxes or assessments which are not shown as existing liens by the records of any taxing authority that levies taxes or assessments on land or by the public records . EXCEPTIONS (continued)Order No. 867896 2 .a) Unpatented mining claims; (b) reservations or exceptions in Patents or in Acts authorizing the issuance thereof; (c) Indian treaty or aboriginal rights, including, but not limited to, easements or equitable servitudes; or, (d) water rights, claims or title to water, whether or not the matters excepted under (a) , (b) , (c) , or (d) are shown by the public records . 3 . Title to any property beyond the lines of the land expressly described herein, or title to streets, roads, avenues, lanes, ways or waterways on which said land abuts, or the right to maintain vaults, tunnels, ramps or any other structure or improvement; or any rights or easements therein unless such property rights or easements are expressly and specifically set forth in the land described herein. 4 . General Taxes, as follows, together with interest, penalty and statutory foreclosure costs, if any, after delinquency: 1st half delinquent May 1; 2nd half delinquent November 1) Tax Account No. Year Billed Paid Balance 162305-9006-05 1999 173 .48 0 . 00 173 .48 162305-9007-04 1999 4, 924 . 33 0 . 00 4 , 924 . 33 162305-9061-07 1999 1, 235 . 75 0 . 00 1, 235 . 75 172305-9171-03 1999 440 .39 0 . 00 440 . 39 162305-9009-02 1999 2, 308 . 69 0 . 00 2, 308 . 69 162305-9010-09 1999 3 , 589 . 82 0 . 00 3, 589 . 82 The above tax parcels comprise the total property described herein. The levy code for the property herein described is 2100 for 1999 . 5 . Conservation (CON) Service Charge, as follows, together with interest, penalty and statutory foreclosure costs, if any, after delinquency: 1st half delinquent May 1; 2nd half delinquent November 1) Tax Account No. Year Billed Paid Balance 162305-9006-05 1999 5 . 00 0 . 00 5 . 00 162305-9007-04 1999 5 . 00 0 . 00 5 . 00 162305-9061-07 1999 5 . 00 0 . 00 5 . 00 172305-9171-03 1999 5 . 00 0 . 00 5 . 00 162305-9009-02 1999 5 . 00 0 . 00 5 . 00 162305-9010-09 1999 5 . 00 0 . 00 5 . 00 Page 2 EXCEPTIONS (continued)Order No. 867896 6 . Noxious Weed Charge, as follows, together with interest, penalty and statutory foreclosure costs, if any, after delinquency: 1st half delinquent May 1; 2nd half delinquent November 1) Tax Account No. Year Billed Paid Balance 162305-9006-05 1999 0 . 94 0 . 00 0 . 94 162305-9007-04 1999 4 . 09 0 . 00 4 . 09 162305-9061-07 1999 1 . 75 0 . 00 1 . 75 172305-9171-03 1999 1 . 21 0 . 00 1 .21 162305-9009-02 1999 2 . 38 0 . 00 2 .38 162305-9010-09 1999 3 . 19 0 . 00 3 . 19 7 . ALL COVENANTS, CONDITIONS, RESTRICTIONS, RESERVATIONS, EASEMENTS, OR OTHER SERVITUDES, if any, disclosed by Lot Line Adjustment No. LUA-95-200-LLA, recorded under Recording No. 9604239004 . RIGHTS OR BENEFITS, IF ANY, WHICH MAY BE DISCLOSED BY THE RECORDED DOCUMENT (S) ABOVE AFFECTING LAND OUTSIDE THE BOUNDARY DESCRIBED IN SCHEDULE A. 8 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE : Transmission line AREA AFFECTED: A strip 200 feet in width running West tc South RECORDING NO. : 2513101 (1421 deeds 270) 9 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE: Transmission line AREA AFFECTED: A strip 100 feet in width running Southerly RECORDING NO. : 2571770 (1455 deeds 174) 10 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE : Electric distribution line AREA AFFECTED: 50 foot strip running diagonally RECORDING NO. : 3425304 11 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE: Ingress and egress AREA AFFECTED: as described therein RECORDING NO. : 4253226 12 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE: Electric distribution line AREA AFFECTED: as described therein RECORDING NO. : 4340046 Page 3 EXCEPTIONS (continued) Order No. 867896 13 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: PURPOSE : Ingress and egress AREA AFFECTED: as described therein RECORDING NO. : 4747362 14 . EASEMENT AND THE TERMS AND CONDITIONS THEREOF: GRANTEE : City of Renton PURPOSE: Sewer interceptor project AREA AFFECTED: Portions, as described therein and as shown on Exhibit D, attached thereto RECORDING NO. : 9410041746 Said instrument was amended under Recording No. 9604100120 . 15 . Reservation contained in deed from State of Washington recorded under Recording No. 2060096, reserving to the grantor all oil, gases, coal, ores, minerals, fossils, etc. , and the right of entry for opening, developing and working the same, and providing that such rights shall not be exercised until provision has been made for full payment of all damages sustained by reason of such entry. Right of State of Washington or its successors, subject to payment of compensation therefor, to acquire right-of-way for private railroads, skid roads, flumes, canals, water courses or other easements for transporting and moving timber, stone, minerals and other products from this and other property, as reserved in deed referred to above . Covers Parcel 1, easterly portion of Parcel 9 and other property) 16 . Reservation contained in deed from State of Washington recorded under Recording No. 4264136, reserving to the grantor all oil, gases, coal, ores, minerals, fossils, etc . , and the right of entry for opening, developing and working the same, and providing that such rights shall not be exercised until provision has been made for full payment of all damages sustained by reason of such entry. Right of State of Washington or its successors, subject to payment of compensation therefor, to acquire right-of-way for private railroads, skid roads, flumes, canals, water courses or other easements for transporting and moving timber, stone, minerals and other products from this and other property, as reserved in deed referred to above . Covers Parcel 2) 17 . Terms and conditions of Coal Mining Lease No. 44 granted by the State of Washington, disclosed on deed recorded under Recording No . 8612231251 . Covers Parcel 2) 18 . UNRECORDED AGREEMENT AND THE TERMS AND CONDITIONS THEREOF: BETWEEN: Thomas F. McMahon, Personal Representative of the Estate of John C. Edwards and the Estate of Anna G. McMahon deceased, and Rainier Sand and Gravel Inc. AND: The City of Renton AS DISCLOSED: In King County Probate Cause No. E236708 REGARDING: Maintenance and drainage Page 4 EXCEPTIONS (continued)Order No. 867896 19 . UNRECORDED REAL PROPERTY MINING AGREEMENT AND THE TERMS AND CONDITIONS THEREOF: BETWEEN: The Estate of John C. Edwards also known as John E. Edwards, et al AND : Metro Land Development, Inc. AS DISCLOSED IN: King County Probate Case No. E236708 and as amended by order under King County Superior Court Cause No. 860374 , dated and filed August 1, 1979 20 . Matters disclosed by Unrecorded Survey by Continental Eng. Co. , dated December 11, 1992 under Job No. 92340, as follows : Encroachment of dirt road onto the Westerly line of the southwest 1/4 of the northwest 1/4 of Section 16 . 21 . AGREEMENT AND THE TERMS AND CONDITIONS THEREOF: RECORDED: February 19, 1997 RECORDING NO. : 9702191181 REGARDING:Sewer Easement and Agreement 22 . ORDINANCE AND THE TERMS AND CONDITIONS THEREOF: RECORDED: June 21, 1996 RECORDING NO. : 9606210966 REGARDING: Assessment District 23 . Reservations contained in deed from the State of Washington recorded under Recording No. 4592023 , reserving to the grantor all oil, gases, coal, ores, minerals, fossils, etc . , and the right of entry for opening, developing and working the same, and providing that such rights shall not be exercised until provision has been made for full payment of all damages sustained by reason of such entry. Right of the State of Washington or its successors, subject to payment of compensation therefor, to acquire rights-of-way for private railroads, skid roads, flumes, canals, water courses or other easements for transporting and moving timber, stone, minerals and other products from this and other land, as reserved in deed referred to above . Covers Parcel 3 and other property) 24 . DEED OF TRUST AND THE TERMS AND CONDITIONS THEREOF: GRANTOR: La Pianta Limited Partnership, a Washington limited partnership TRUSTEE: Transnation Title Insurance Company BENEFICIARY: M.A. Segale, Inc . , a Washington corporation ADDRESS : 18010 Southcenter Parkway, Tukwila, Washington 98188 LOAN NO. : ORIGINAL AMOUNT: 9, 191, 440 . 10 DATED:February 29, 1996 RECORDED: February 29, 1996 RECORDING NO. : 9602291884 Investigation should be made to determine the present balance owing with the appropriate lender/agency/individual . Page 5 EXCEPTIONS (continued)Order No. 867896 25 . ASSIGNMENT OF LEASE FOR SECURITY PURPOSES AND THE TERMS AND CONDITIONS THEREOF: LESSOR'S INTEREST ASSIGNED TO: M.A. Segale, Inc. , a Washington corporation BY ASSIGNMENT RECORDED: February 29, 1996 RECORDING NO. : 9602291885 Said assignment given as additional security for the deed of trust recorded under Recording No. 9602291884, shown at paragraph preceding herein. BW/amh ENCLOSURES : Sketch Paragraphs 23-25 Copies have been sent to the following: TRIAD ASSOCIATES 11814 115TH AVE NE KIRKLAND, WA 98034 Attn: BRAD FREEMAN Page 6 Order No. 867896 LEGAL DESCRIPTION: PARCELS 1, 2, 3 , 4, 9 AND 10 OF CITY OF RENTON LOT LINE ADJUSTMENT NO. LUA-95-200-LLA, ACCORDING TO THE LOT LINE ADJUSTMENT RECORDED UNDER KING COUNTY RECORDING NO. 9604239004 , BEING A PORTION OF THE NORTHEAST 1/4 OF THE NORTHEAST 1/4 AND NORTH 1/2 OF SOUTHWEST 1/4 OF SECTION 17 AND OF THE WEST 1/2 OF THE NORTHWEST 1/4 OF SECTION 16, ALL IN TOWNSHIP 23 NORTH, RANGE 5 EAST W.M. ; SITUATE IN THE CITY OF RENTON, COUNTY OF KING, STATE OF WASHINGTON. Page 7 SCHEDULE OF EXCLUSIONS FROM COVERAGE O] GUARANTEE obtaining witnesses,prosecuting nding the action or lawful act which in the opinion of the Company may be necessary or desirable to establish the title to the estate or interest as I. Except to the extent that specific assurances are provided in Schedule A of this stated herein,or to establish the lien rights of the Assured. If the Company is prejudiced by Guarantee. the Company assumes no liability for loss or damage by reason of the the failure of the Assured to furnish the required cooperation,the Company's obligations to following: the Assured under the Guarantee shall terminate. a) Defects,liens.encumbrances,adverse claims or other matters against the title,whether or not shown by the public records. 5. Proof of Loss or Damage. b) (1) Taxes or assessments of any taxing authority that levies taxes or In addition to and after the notices required under Section 2 of these Conditions assessments on real property;or,(2) Proceedings by a public agency which may result in and Stipulations have been provided to the Company,a proof of loss or damage signed and taxes or assessments,or notices of such proceedings,whether or not the matters excluded sworn to by the Assured shall be furnished to the Company within ninety(90)days after the under(I)or(2)are shown by the records of the taxing authority or by the public records. Assured shall ascertain the facts giving rise to the loss or damage. The proof of loss or c) (1) Unpatented mining claims;(2)reservations or exceptions in patents or darftage shall describe the matters covered by this Guarantee which constitute the basis of loss in Acts authorizing the issuance thereof;(3)water rights,claims or title to water,whether or or damage and shall state,to the extent possible,the basis of calculating the amount of the not the matters excluded under(1),(2)or(3)are shown by the public records. loss or damage. If the Company is prejudiced by the failure of the Assured to provide the required proof of loss or damage, the Company's obligation to such assured under the 2. Notwithstanding any specific assurances which are provided in Schedule A of this Guarantee shall terminate. In addition,the Assured may reasonably be required to submit to Guarantee,the Company assumes no liability for loss or damage by reason of the examination under oath by any authorized representative of the Company and shall produce following: for examination,inspection and copying,at such reasonable times and places as may be a) Defects,liens,encumbrances,adverse claims or other matters affecting the designated by any authorized representative of the Company,all records,books,ledgers, title to any property beyond the lines of the land expressly described in the description set checks,correspondence and memoranda,whether bearing a date before or after Date of forth in Schedule(A),(C)or in Part 2 of this Guarantee,or title to streets,roads,avenues, Guarantee,which reasonably pertain to the loss or damage. Further,if requested by any lanes,ways or waterways to which such land abuts,or the right to maintain therein vaults, authorized representative of the Company,the Assured shall grant its permission,in writing. tunnels,ramps or any structure or improvements;or any rights or easements therein,unless for any authorized representative of the Company to examine,inspect and copy all records, such property,rights or easements are expressly and specifically set forth in said description. books,ledgers.checks,correspondence and memoranda in the custody or control of a third b) Defects,liens,encumbrances,adverse claims or other matters,whether or party, which reasonably pertain to the loss or damage. All information designated as not shown by the public records: (I)which are created,suffered,assumed or agreed to by confidential by the Assured provided to the Company pursuant to this Section shall not be one or more of the Assureds;(2)which result in no loss to the Assured;or(3)which do not disclosed to others unless,in the reasonable judgment of the Company,it is necessary in the result in the invalidity or potential invalidity of any judicial or non-judicial proceeding which administration of the claim. Failure of the Assured to submit for examination under oath. is within the scope and purpose of the assurances provided. produce other reasonably requested information or grant permission to secure reasonably c) The identity of any party shown or referred to in Schedule A. necessary information from third parties as required in the above paragraph,unless prohibited d) The validity,legal effect or priority of any matter shown or referred to in by law or governmental regulation,shall terminate any liability of the Company under this this Guarantee. Guarantee to the Assured for that claim. GUARANTEE CONDITIONS AND STIPULATIONS 6. Options to Pay or Otherwise Settle Claims: Termination of Liability. 1. Definition of Terms. In case of a claim under this Guarantee,the Company shall have the following additional The following terms when used in the Guarantee mean: options: a)the"Assured": the party or parties named as the Assured in this Guarantee, a)To Pay or Tender Payment of the Amount of Liability or to Purchase the or on a supplemental writing executed by the Company. Indebtedness. b)"land": the land described or referred to in Schedule(A)(C)or in Part 2,and The Company shall have the option to pay or settle or compromise for or in the name of the improvements affixed thereto which by law constitute real property. The term"land"does Assured any claim which could result in loss to the Assured within the coverage of this not include any property beyond the lines of the area described or referred to in Schedule Guarantee,or to pay the full amount of this Guarantee or,if this Guarantee is issued for the A)(C)or in Part 2,nor any right,title,interest,estate or easement in abutting streets,roads, benefit of a holder of a mortgage or a lienholder,the Company shall have the option to avenues,alleys,lanes,ways or waterways.purchase the indebtedness secured by said mortgage or said lien for the amount owing c)"mortgage":mortgage,deed of trust,trust deed,or other security instrument. thereon,together with any costs,reasonable attorneys'fees and expenses incurred by the d) "public records": records established under state statutes at Date of Assured claimant which were authorized by the Company up to the time of purchase. Guarantee for the purpose of imparting constructive notice of matters relating to real property Such purchase,payment or tender of payment of the full amount of the Guarantee shall to purchasers for value and without knowledge. terminate all liability of the Company hereunder. In the event after notice of claim has been e)"date": the effective date. given to the Company by the Assured the Company offers to purchase said indebtedness,the owner of such indebtedness shall transfer and assign said indebtedness,together with any 2. Notice of Claim to be Given by Assured Claimant. collateral security,to the Company upon payment of the purchase price. An Assured shall notify the Company promptly in writing in case knowledge shall come to Upon the exercise by the Company of the option provided for in Paragraph(a)the Company's an Assured hereunder of any claim of title or interest which is adverse to the title to the estate obligation to the Assured under this Guarantee for the claimed loss or damage,other than to or interest,as stated herein,and which might cause loss or damage for which the Company make the payment required in that paragraph,shall terminate,including any obligation to may be liable by virtue of this Guarantee. If prompt notice shall not be given to the continue the defense or prosecution of any litigation for which the Company has exercised Company,then all liability of the Company shall terminate with regard to the matter or its options under Paragraph 4,and the Guarantee shall be surrendered to the Company for matters for which prompt notice is required;provided,however,that failure to notify the cancellation. Company shall in no case prejudice the rights of any Assured under this Guarantee unless the b)To Pay or Otherwise Settle With Parties Other Than the Assured or With the Company shall be prejudiced by the failure and then only to the extent of the prejudice. Assured Claimant. To pay or otherwise settle with other parties for or in the name of an Assured claimant any 3. No Duty to Defend or Prosecute. claim assured against under this Guarantee,together with any costs,attorneys'fees and The Company shall have no duty to defend or prosecute any action or proceeding to which expenses incurred by the Assured claimant which were authorized by the Company up to the the Assured is a party, notwithstanding the nature of any allegation in such action or time of payment and which the Company is obligated to pay. proceeding. Upon the exercise by the Company of the option provided for in Paragraph(b)the Company's obligation to the Assured under this Guarantee for the claimed loss or damage,other than to 4. Company's Option to Defend or Prosecute Actions;Duty of Assured Claimant to make the payment required in that paragraph,shall terminate,including any obligation to Cooperate. continue the defense or prosecution of any litigation for which the Company has exercised Even though the Company has no duty to defend or prosecute as set forth in Paragraph 3 its options under Paragraph 4. above: a)The Company shall have the right,at its sole option and cost,to institute and 7. Determination and Extent of Liability. prosecute any action or proceeding,interpose a defense,as limited in(b),or to do any other This Guarantee is a contract of Indemnity against actual monetary loss or damage sustained act which in its opinion may be necessary or desirable to establish the title to the estate or or incurred by the Assured claimant who has suffered loss or damage by reason of reliance interest as stated herein,or to establish the lien rights of the Assured,or to prevent or reduce upon the assurances set forth in this Guarantee and only to the extent herein described,and loss or damage to the Assured. The Company may take any appropriate action under the subject to the Exclusions From Coverage of This Guarantee. terms of this Guarantee,whether or not it shall be liable hereunder,and shall not thereby The liability of the Company under this Guarantee to the Assured shall not exceed the least concede liability or waive any provision of this Guarantee. If the Company shall exercise its of: rights under this paragraph,it shall do so diligently. a)the amount of liability stated in Schedule A or in Part 2; b)If the Company elects to exercise its options as stated in Paragraph 4(a)the b)the amount of the unpaid principal indebtedness secured by the mortgage of Company shall have the right to select counsel of its choice(subject to the right of such an Assured mortgagee, as limited or provided under Section 6 of these Conditions and Assured to object for reasonable cause)to represent the Assured and shall not be liable for Stipulations or as reduced under Section 9 of these Conditions and Stipulations,at the time and will not pay the fees of any other counsel,nor will the Company pay any fees,costs or the loss or damage assured against by this Guarantee occurs,together with interest thereon. expenses incurred by an Assured in the defense of those causes of action which allege matters or not covered by this Guarantee. c)the difference between the value of the estate or interest covered hereby as c)Whenever the Company shall have brought an action or interposed a defense stated herein and the value of the estate or interest subject to any defect,lien or encumbrance as permitted by the provisions of this Guarantee,the Company may pursue any litigation to assured against by this Guarantee. final determination by a court of competent jurisdiction and expressly reserves the right,in its sole discretion,to appeal from an adverse judgment or order. 8. Limitation of Liability. d)In all cases where this Guarantee permits the Company to prosecute or a)If the Company establishes the title,or removes the alleged defect,lien or provide for the defense of any action or proceeding,an Assured shall secure to the Company encumbrance,or cures any other matter assured against by this Guarantee in a reasonably the right to so prosecute or provide for the defense of any action or proceeding,and all diligent manner by any method,including litigation and the completion of any appeals appeals therein,and permit the Company to use,at its option,the name of such Assured for therefrom,it shall have fully performed its obligations with respect to that matter and shall this purpose. Whenever requested by the Company,an Assured,at the Company's expense, not be liable for any loss or damage caused thereby. shall give the Company all reasonable aid in any action or proceeding,securing evidence, CONDITIONS AND STIPULATIONS CONTINUED ON BACK COVER CLTA Guarantee Conditions and Stipulations Form 2015-7 (Rev. 12-15-95) ORI('INAI CONDITIONS AND STIPULATIONS CONTINUED b)In the event of any litigation by the Company or with the Company's consent, 12. Arbitration. the Company shall have no liability for loss or damage until there has been a final determination by a court of competent jurisdiction,and disposition of all appeals therefrom, Unless prohibited by applicable law,either the Company or the Assured may demand adverse to the title,as stated herein. arbitration pursuant to the Title Insurance Arbitration Rules of the American Arbitration c)The Company shall not be liable for loss or damage to any Assured for Association. Arbitrable matters may include,but are not limited to,any controversy or claim liability voluntarily assumed by the Assured in settling any claim or suit without the prior between the Company and the Assured arising out of or relating to this Guarantee,any service written consent of the Company.of the Company in connection with its issuance or the breach of a Guarantee provision or other obligation. All arbitrable matters when the Amount of Liability is$1,000,000 or less 9. Reduction of Liability or Termination of Liability. shall be arbitrated at the option of either the Company or the Assured. All arbitrable matters All payments under this Guarantee,except payments made for costs.attorneys' when the amount of liability is in excess of$1,000,000 shall be arbitrated only when agreed fees and expenses pursuant to Paragraph 4 shall reduce the amount of liability pro Canto. to by both the Company and the Assured. The Rules in effect at Date of Guarantee shall be binding upon the parties. The award may include attorneys'fees only if the laws of the state 10. Payment of Loss.in which the land is located permits a court to award attorneys'fees to a prevailing party. a)No payment shall be made without producing this Guarantee for endorsement Judgment upon the award rendered by the Arbitrator(s)may be entered in any court having of the payment unless the Guarantee has been lost or destroyed,in which case proof of loss jurisdiction thereof. or destruction shall be furnished to the satisfaction of the Company. b)When liability and the extent of loss or damage has been definitely fixed in The law of the situs of the land shall apply to an arbitration under the Title Insurance accordance with these Conditions and Stipulations,the loss or damage shall be payable within Arbitration Rules. thirty(30)days thereafter. A copy of the Rules may be obtained from the Company upon request. 11. Subrogation Upon Payment or Settlement. Whenever the Company shall have settled and paid a claim under this Guarantee,all right of 13. Liability Limited to This Guarantee;Guarantee Entire Contract. subrogation shall vest in the Company unaffected by any act of the Assured claimant. a)This Guarantee together with all endorsements,if any,attached hereto by the The Company shall be subrogated to and be entitled to all rights and remedies which the Company is the entire Guarantee and contract between the Assured and the Company. In Assured would have had against any person or property in respect to the claim had this interpreting any provision of this Guarantee,this Guarantee shall be construed as a whole. Guarantee not been issued. If requested by the Company,the Assured shall transfer to the Company all rights and remedies against any person or property necessary in order to perfect b)Any claim of loss or damage,whether or not based on negligence,or any this right of subrogation.The Assured shall permit the Company to sue,compromise or settle action asserting such claim,shall be restricted to this Guarantee. in the name of the Assured and to use the name of the Assured in any transaction or litigation involving these rights or remedies. c)No amendment of or endorsement to this Guarantee can be made except by a writing endorsed hereon or attached hereto signed by either the President,a Vice President. If a payment on account of a claim does not fully cover the loss of the Assured the Company the Secretary,an Assistant Secretary,or validating officer or authorized signatory of the shall be subrogated to all rights and remedies of the Assured after the Assured shall have Company. recovered its principal,interest,and costs of collection. 14. Notices,Where Sent. All notices required to be given the Company and any statement in writing required to be furnished the Company shall include the number of this Guarantee and shall be addressed to TRANSNATION TITLE INSURANCE COMPANY, 101 Gateway Centre Parkway. Gateway One,Richmond,Virginia 23235-5153. O ur 0 CCO iF > = ' C gii wE nytH_ cOw m QA Mar-31 -99 04 : 06P Law Ott ices cic 11:3000141/ 4 HALINEN LAW OFFICES, P.S. A Professional Service Corporation David L,.Halinen,P.E.Bellevue Place/Seafirst Building . 425)454-8272 10500 NE 8th,Suite 1900 Fax(425)646-3467 Bellevue,Washington 98004 MEMORANDUM ci ,o Date: March 31, 1999 110 4 4. 6 9I T04 tiAFrom: David L. Halinen 47,99 To: City of Renton Department of Economic Development and Neighborh60 Strategic Planning And To:The Renton City Council and Renton Planning Commission Subject:La Pianta Comprehensive Plan Amendments and Rezone La Pianta's Proposed Text Amendments to both (a) Comprehensive Plan Policy LU-61 and (b) Portions of the R-14 Zone Regulations Proposed Text Amendment to Comprehensive Plan Policy LU-61 La Pianta Limited Partnership hereby proposes that Renton Comprehensive Plan Policy LU-61 be amended to read as follows (with the proposed new text underlined): Policy LU-61. Longer townhouse building clusters, and other multi-family building clusters, considered secondary residential types, should be limited in size so that the mass and scale of the cluster retains a small scale multi-family character rather than a garden apartment development style, with an exception for portions of projects in the Residential Planned Neighborhood designation where the residents are legally age- restricted to persons 55 years of age or older consistent with applicable Federal law. Limits on the number of units which may be attached in one cluster should be established in the development regulations. Concepts for R-14 Zone Text Amendments Consistent with La Pianta's proposed amendment to Comprehensive Plan Policy LU-61, La Pianta hereby seeks to have the City approve text amendments to the R-14 regulations that would permit the following(with the exact language to be developed in conjunction with Renton Strategic Planning staff later during the Comprehensive Plan Amendment/Rezone review process): 1) Provide for"senior apartment buildings" as Secondary Units within the R-14 zone with (a) the overall number of flats in such buildings in each R-14 Page 1 Mar-31 -99 04 : 06P Law Uttices L5.1 L/L uica r . uc development limited by the 50% Secondary Uses limitation of the R-14 zone and(b) no zoning limitation on the number of flats in each such building; 2) Provide for no minimum lot size for senior apartment buildings; 3) Provide a special height limit for senior apartment buildings that would accommodate up to four stories (on the order of 45 feet) for situations like that of the La Pianta site where topographic conditions will allow such building(s) to be constructed adjacent to the lower side of an existing slope or bank; and 4) Provide special parking regulations for senior apartment buildings (to be developed with Renton Strategic Planning staff later during the Comprehensive Plan Amendment/Rezone review process), Page 2 HALINEN LAW OFFICES, P.S. A Professional Service Corporation David L. Halinen,P.E. Bellevue Place/Seafirst Building 425)454-8272 10500 NE 8th,Suite 1900 Fax(425)646-3467 Bellevue,Washington 98004 March 31, 1999 CITY OF RENTON HAND-DELIVERED RECEIVED City of Renton Department of Economic Development and MAR 1999 Neighborhood Strategic Planning LlUiti_UttsKi DIVISION 1055 S. Grady Way, Sixth Floor Renton, Washington 98055 Attn: Rebecca Lind, Senior Planner RE: La Pianta Limited Partnership's Application for (1) Comprehensive Plan Land Use Map Amendments and Rezone and (2) Text Amendments to both (a) Comprehensive Plan Policy LU-61 and (b) Portions of the R-14 Zone Regulations Dear Ms. Lind: As a follow-up to the pre-submittal conference that Craig Krueger of Dodds Engineers, Inc. and I had with you this Monday, March 29th, on behalf of La Pianta Limited Partnership, a Washington limited partnership, I herewith submit to you the following items to constitute the above- referenced application (item numbers refer to the City's requirement list): 1) Twelve (12) copies of the completed Master Application form; 2) Twelve (12) copies (including the original) of a completed Environmental Checklist signed by Mr. Krueger; 3) Three (3) copies of a composite of relevant King County Assessors Maps depicting the site and all properties within 300 feet of the site; 4) Three(3) copies of a current title report (a"Second Subdivision Guarantee" dated March 26, 1999) from Transnation Title Insurance Company; 5) Two (2) sets of self-adhesive mailing labels for all property owners within 300 feet of the boundaries of the site; 6) Two (2) copies of a completed, signed and notarized List of Surrounding Property Owners form; 7) Legal Documents (None: not applicable); 8) A check from my office in the amount of$19.14 for required postage (which is equivalent to $0.33 per mailing label for each of the provided 58 labels); City of Renton Department of Economic Development and Neighborhood Strategic Planning Attn: Rebecca Lind, Senior Planner March 31, 1999 Page 2 9) Twelve (12) copies of a Project Narrative; 10) Twelve (12) copies of a Neighborhood Detail Map; and 11) Twelve (12) copies of a Property Map. During our meeting, you deferred the usual requirement for submittal of PMT reductions of the maps item 12 on the City's application requirements list) and, accordingly, none are herewith provided. In addition, I herewith enclose a memorandum that I have prepared setting forth La Pianta's Proposed Text Amendments to both (a) Comprehensive Plan Policy LU-61 and (b) portions of the R-14 zone regulations. I also enclose a Segale Business Park check payable to the order of the City of Renton in the sum of$5,200 as an application fee for the subject application ($5,200 being the amount that you explained on Monday was due for the application). Please phone me if you have any questions or comments concerning this application. Thank you for your cooperation. Sincerely, HALINEN LAW OFFICES, P.S. Jo_ David L. Hall n Enclosures cc: La Pianta Limited Partnership Attn: Mario Segale and Ann Nichols (with copies of enclosures) Donald J. Merlino (with copies of enclosures) Richard Gilroy (with copies of enclosures) Craig Krueger, Dodds Engineers, Inc. (with copies of enclosures) D:\CF\2009\039\LIND.LT1.wpd City of Renton WA Reprinted: 03/31/99 16 :41 Receipt Receipt Number: R9901374 Amount : 5, 200 . 00 03/31/99 16 :41 Payment Method: CHECK Notation: #24358 SEGALE BU Init : LN Project #: LUA99-054 Type: LUA Land Use Actions Total Fees: 5, 200 . 00 This Payment 5, 200 . 00 Total ALL Pmts: 5, 200 . 00 Balance: 00 Account Code Description Amount 000 .345 . 81 . 00 . 0007 Environmental Review 200 . 00 000 . 345 . 81 . 00 . 0014 Rezone 4, 000 . 00 000 .345 . 81. 00 . 0005 Comprehensive Plan Amend 1, 000 . 00 City of Renton WA Reprinted: 03/31/99 16 :42 Receipt Receipt Number: R9901375 Amount: 19 . 14 03/31/99 16 :42 Payment Method: CHECK Notation: #5995 HALINEN LA Init: LN Project # : LUA99-054 Type: LUA Land Use Actions Total Fees : 5, 219 . 14 This Payment 19 . 14 Total ALL Pmts : 5, 219 . 14 Balance: 00 Account Code Description Amount 000 . 05 .519 .90 .42 . 1 Postage 19 . 14 q q,054, R, CEDAR CREST PHASES I II III IV Renton, Washington Storm Drainage Report Prepared by: Scott R. Borgeson Reviewed by: Donald J. Hill, P.E. MIIIELWNW TRIAD ASSOCIATES F' ebruar 1 1 1999 TRIAD JOB # 95 - 123 PHASES I & II CITY OF RENTON RECEIVED MAY 2 71999 Renton, Washington BUILDING DIVISION Storm Drainage Report Prepared by: Scott R. Borgeson 04D Reviewed by: O o wAsyi, e Donald J. Hill, P.E.y ox 14 jisTE,L53;0, 5). ZONAL EXPIRES 6/s/qq V TRIAD ASSOCIATES Februar 1 1 1999 TRIAD JOB # 95 - 1 23 Page 1 King County Building and Land Development Division TECHNICAL INFORMATION REPORT MR) WORKSHEET PART 1 PROJECT OWNER AND PART 2 PROJECT LOCATION PROJECT ENGINEER AND DESCRIPTION a Pianta Ltd . Ptnrshp . , InProjectOwner18000AndoverPrk . U. Ste 210ProjectName Cedar Crest Address UBA/Segale Business Prk . LocationTukwila , {J A 9 01 0-9---4 7 9 B Phone ( 206 ) 575-3200 Township 23N Donald J . Hill Range 5E Project Engineer 16 Company Triad Associates Section 1 1 81 4 1 1 5 t h Ave . NE Project Size: 1 2 7 AC Address Phone i r>< and t,J-A a-6- r s 0 2 3 Upstream Drainage Basin Size 3 AC425 ) 821 -8448 PART 3 TYPE OF PERMIT APPLICATION PART 4 OTHER PERMITS n Subdivision n DOF/G HPA f-1 Shoreline Management I 1 Short Subdivision Ij COE 404 I Rockery 1 I Grading 1 1 DOE Darn Safety 1 I Structural Vaults I I Commercial I FEMA Floodplain 1 I Other XJ Other Manufactured/Modular J COE Wetlands I I HPA Home Community PART 5 SITE COMMUNITY AND DRAINAGE BASIN Community Drainage Basin Cedar River PART 6 SITE CHARACTERISTICS I River 1 I Floodplain l 1 Stream I J Wetlands I 1. Critical Stream Reach Seeps/Springs I Depressions/Swales I High Groundwater Table I I I aka Groundwater Recharge I I Steep Slopes I I Other I 1 Lakeside/Erosion Hazard PART 7 SOILS . Soil Type Slopes Erosion Potential Erosive Velocities Everett Variable Low Low I I Additional Sheets Attatched I Page 2 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET RT 8 DEVELOPMENT LIMITATIONS 411 REFERENCE LIMITATION/SITE CONSTRAINT CI Ch.4-Downstream Analysis Cl Cl Cl CI r- Additional Sheets Attatched PA-T 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTION x Sedimentation Facilities x 1 Stabilize Exposed Surface I x Stabilized Construction Entrance Fri Remove and Restore Temporary ESC Facilities l x Perimeter Runoff Control I x I Clean and Remove All Silt and Debris Clearing and Grading Restrictions I x I Ensure Operation of Permanent Facilities Cover Practices I I Rag Limits of NGPES x Construction Sequence l I Other C Other PART 10 SURFACE WATER SYSTEM I I Grass Lined Channel I 1 Tank Ix I Infiltration Method of Analysis I xl Pipe System I l Vault I I Depression S . B . u . H . Cl Open Channel I I Energy Dissapator I I Flow Dispersal Compensation/Mitigation I I Dry Pond I I Wetland I I Waiver of Eliminated Site Storage I xl Wet Pond I I Stream I I Regional Detention Stormwater generated on-site will be infiltrateBriefDescriptionofSystemOperationd and off-site tributary areas will be bypassed . Faci ity Related Site Limitations I I Additional Sheets AttatchedRafeonceFacilityLimitation PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS May require special structural review) I x I Drainage Easement C Cast in Place Vault I 1 Other I I Access Easement 1 I Retaining Wall I I Native Growth Protection Easement I 3ockery>4'High I x I Tract I I ,Structural on Steep Slope J Other PART 14 SIGNATURE OF PROFESSIONAL ENGINEER I or a civil engineer under my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the f_CfL j 2//,/Ql attatchments. To the best of my knowledge the information provided here is accurate. Sig fit* I/90 TABLE OF CONTENTS Page INTRODUCTION 1 VICINITY MAP 1 DRAINAGE CONCEPT 2 CITY OF RENTON AQUIFER PROTECTION AREAS EXHIBIT 3 DOWNSTREAM ANALYSIS 5 DOWNSTREAM ANALYSIS EXHIBIT 6 DETENTION CALCULATIONS 7 OFF-SITE RELEASE 9 Onsite Existing Condition Hydrographs 9 Bypass Area Developed Condition Hydrographs 10 Offsite Release Summary 10 INFILTRATION POND A 11 Developed Condition Hydrographs for Area Tributary to Pond A 11 Infiltration Pond A Level Pool Routing 11 Live Storage 12 Water Quality 12 CONVEYANCE CALCULATIONS 14 EMERGENCY OVERFLOW PIPE CONVEYANCE CALCULATIONS 18 EROSION CONTROL 19 APPENDIX SCS Soils Map Table 3.5.2B—SCS W.Washington Runoff Curve Numbers 2, 10,25,& 100-Year Isopluvials Times of Concentration Exhibit,Basin 1 Water Works Output Table 4.3.3B—Coefficients for the Rational Method"iR"-Equation Table of Flows Used for Hydraulic Grade Line Calculations for Each Catchment Area Hydraulic Grade Line Calculations Hydrogeologic&Geotechnical Services/Report Addendum prepared by Geo Engineers,Inc.,April 6, 1995 Hydrogeologic&Geotechnical Services/Report prepared by Geo Engineers,Inc.,October 24, 1994 Preliminary Geotechnical Report prepared by CH2M Hill,May, 1988 Preliminary Hydrogeologic&Geotechnical Report prepared by Golder Associates,January, 1988 Level 1 Drainage Study and Preliminary Storm Drainage Calculations for Cedar Crest Manufactured/Modular Home Community prepared by Barghausen Consulting Engineers,Inc., Revision Dated November 4, 1994 Hearing Examiner's Report and Decision/File No.LUA-95-023,CU/V/MHP/ECF,May 23, 1995 In Pocket at End of Report Pipe Tributary Area Exhibit,Phases 1 &2 STORM DRAINAGE REPORT FOR CEDAR CREST—Page i Phases 1 &2 INTRODUCTION The proposed project is to construct a 401 site manufactured/modular home community on approximately 127 acres located north of and adjacent to Maple Valley Road (State Route 169) and south of N.E. Third Street. The project is separated into four construction phases. This report has been prepared to address storm drainage design for Phases 1 and 2. See the report titled "Cedar Crest — Phases III & IV — Storm Drainage Report"for storm drainage design and analysis related to Phases 3 and 4. The site is bordered on the west by the recently constructed extension of Edmonds Avenue N.E. and the Plat of La Colina. The site is bordered on the east and northeast by a King County facility. More generally, the site is located in Section 16, Township 23 North, Range 5 East, W.M. in the City of Renton, King County,Washington. Please refer to the Vicinity Map located below. Approximately 85 acres of the site will be developed, while 42 acres will remain native. The site has been used as a gravel pit, which has been mined of most of the useful coarse gravel materials. The underlying foundation material is primarily fine to coarse-grained glacial outwash,which allows for good infiltration of surface water. A detailed description of the on-site soils can be found in the Hydrogeologic and Geotechnical Services/Report prepared by Geo Engineers, Inc. in October, 1994. This report is located in the Appendix. NF PARK DR AIM aralx SITE 51 NE 4TH ST NE 3R9 CREENW00D CEMETERY C/TY OF RENTON BAR 9e A ' P 9 VICINITY MAP Not to Scale STORM DRAINAGE REPORT FOR CEDAR CREST—Page 1 Phases 1 & 2 DRAINAGE CONCEPT The storm drainage system for the proposed project was designed with reference to standards found within the 1990 King County Surface Water Design Manual (KCSWDM) and as shown on the Grading & Utility Plans that accompany this report. Currently the majority of the on-site and off-site (upstream) stormwater infiltrates into the ground. The remainder is conveyed,through channels that were constructed as shown on the Grading/Temporary Erosion and Sedimentation Control Plans (previously approved by the City of Renton), to a Type II catch basin located approximately 500 feet south of the northwest corner of the site. From this structure, the water flows via a 30-inch underground pipe to an open basin that is located just outside the northwest corner of the site. A description of the existing conveyance system downstream from this point can be found in the Downstream Analysis section that follows this section. The site lies within two separate City of Renton Aquifer Protection Zones (see City of Renton Aquifer Protection Areas on the following page). The boundary line between the two zones runs east to west across the property, segmenting the southern portion of the property into APA Zone 1, while the northern portion is classified as APA Zone 2. This division line is also shown on the Pipe Tributary Area Exhibit,located in the Appendix. Per the Conditions of Approval for Cedar Crest (see Hearing Examiner's Report and Decision located in the Appendix), all of the stormwater generated on-site must be infiltrated. Since infiltration of stormwater is restricted within APA Zone 1, all of the infiltration facilities for this project have been sited within APA Zone 2. The site has been divided into two basins, with Basin#1 covering the northern portion of the site and both Phases 1 and 2 of the project. Basin#2 covers the remainder of the site, and is coincident with Phases 3 and 4 of the project. The areas tributary to each sub-basin within Basin #1 can be seen on the Pipe Tributary Area Exhibit(see Appendix). This report will focus specifically on the storm drainage issues of Basin#1. The stormwater generated within Basin#1 will be collected in a tightline conveyance system and directed to the existing water quality/detention/infiltration facility, located along the western property boundary of the site and south of the proposed Cedar Crest Parkway, hereafter referred to as Pond A. The stormwater will first enter a three-celled wetpond(cell 2 and cell 3 are existing)that will provide water quality enhancement prior to the stormwater entering the infiltration pond. The infiltration pond will provide live storage detention to allow the 2, 10,and 100-year/24-hour storm events to be released entirely through infiltration. At the recommendation of Geo Engineers, Inc. (see Appendix), an approximately 78,000 s.f., 4' deep infiltration blanket has already been constructed as a part of the construction of Pond A, extending to the north from the northwest corner of Pond A, in order to provide ample area to distribute the infiltration and therefore increase the effective percolation rate. Finally, there are two bypass areas of Basin#1, which will be conveyed via the Emergency Overflow Pipe to the natural discharge point in the northwest corner of the site. One area is 4.30 acres lying along the STORM DRAINAGE REPORT FOR CEDAR CREST—Page 2 Phases 1 & 2 05/07/98 06:27 FAX 425 235 2541 RENTON 1'/13/t' w_,,r,.. 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'v y{•: t t?!.$4.......i cy,XS,:,',r:::••,.yr'4J.+r.'.G•:.:.4 n o I • j16)t•',.:c'e.:, 0 2 5 0 ` v 0 0 0rwa 7,c i j F 1 t J Y au t df,a va.A i:Jr. 2 r I M YMwit w s`WPIA r s . . T•cinied ServicesiCITY OF RENTON CITY LIMITS Works AQUIFER PROTECTION AREASaA.aOnl•,D. v4.,..ki PRODUCTION WELL 26 4.puii 7997 DOWNSTREAM ANALYSIS As described previously, the stormwater generated on-site will all be infiltrated on-site. However, an Emergency Overflow Pipe system has been designed and installed to convey the stormwater that would be discharged by Pond A(and/or also Pond B/C which will serve Phases 3 and 4) in the event of failure. This pipe is also designed to convey the runoff from the on-site bypass areas and the off-site(upstream)tributary area. The 30-inch diameter pipe follows the alignment of Road A (Cedar Crest Parkway) until it makes a jog to connect to a type II catch basin with solid cover that is located approximately 500 feet south of the northwest corner of the site. This structure is labeled as CB OV-1A on both the Pipe Tributary Area Exhibit see Appendix)and the Downstream Analysis Exhibit(next page). From this structure, the stormwater continues through approximately 157 feet of 30-inch underground H.D.P.E.pipe to an open pond that is located just outside the northwest corner of the site. Stormwater from this basin overflows into a 48-inch diameter corrugated metal pipe riser and flows through approximately 168 feet of 48-inch corrugated metal pipe at roughly a 5 percent slope. This pipe discharges into a drainage channel that is well defined and heavily vegetated,and travels westerly for approximately 300 feet. Here it discharges into an open pond that is approximately 100 feet by 50 feet and approximately 3 to 5 feet deep. The pond is located along the south margin of N.E. 3'a Street, and east of Blaine Avenue N.E., adjacent to the entrance into the Mount Olivet Cemetery. The stormwater exits this pond through an overflow structure with a birdcage, and enters into a system of approximately 1,250 feet of pipe (18" followed by 24") that runs along the southern margin of N.E. 3`a Street,eventually discharging into a system near I-405. By this point,the Cedar Crest site makes up less than 10 percent of the contributing basin,and so drainage systems, which were further downstream, were not studied. This downstream flow path was analyzed while conveying heavy rains during a site visit by Triad Associates on October 13, 1998. The drainage course was working properly and no signs of erosion or flooding problems were evident. A similar summary of downstream conditions is in the Level 1 Drainage Study and Preliminary Storm Drainage Report by Barghausen Consulting Engineers,Inc.,located in the Appendix. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 5 Phases 1 &2 northeast site corner. It will remain as an undeveloped slope. The other area is a 1.47 acre naturally graded gully area in the northwest corner of the site that is significantly lower than the remainder of the site. The goal of this proposed drainage system is to provide infiltration in order to recharge groundwaters, to prevent adverse impacts to downstream areas,and to maintain the overall hydrologic balance of the site and surrounding area. Currently the off-site (upstream) stormwater (3.01 acres), the on-site generated stormwater that does not infiltrate, and some of the groundwater base flows contribute to the downstream flow that discharges at the northwest corner of the site. In order to maintain this flow, the off-site upstream) and the bypass (upstream) flows will be collected by a gravel trench drain that will follow the toe of the slope that runs along the east property line. Stormwater flows from both above and below ground will be captured by this system and channeled to the site's natural discharge point via the emergency overflow pipe. The Conditions of Approval questioned how the project site and neighboring areas would be affected by infiltrating stormwater in the infiltration ponds rather than distributing it over the entire site. It appears that the stormwater that infiltrates in the existing condition, both on-site and off-site(upstream), flows naturally towards the northwest corner of the site. In our opinion, it appears that the stormwater infiltrated on-site in the developed condition will follow the same general flow patterns toward the northwest corner of the site, and will help to maintain the existing downstream flows. This is confirmed by the location of the infiltration facility, where the infiltration pond (Pond A) and the adjoining infiltration blanket are situated back from the west property line of the site to allow the infiltrated flows to spread out as the flows follow the apparent westerly gradient. This is also confirmed by the orientation of the infiltration facility where Pond A and the infiltration blanket are oriented and spread out in the north-south direction to better disperse the infiltrated flows so that they more closely match the existing condition. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 4 Phases 1 &2 IIINIMINIIIIIIMIN. 110 ....mtimimsffinvimimmimmigismilimillis. 1 ./ ' ''' 4?4'.*'.. V*"•7,7 IIY. /,;',/ y 1, tit 7 . 3c, I / Ili ./ 1: „ ... .1.1.. __.•./.4,11, i PT ;---—---4----—___ 77 % o lit 4-._. N44,,,(/ - Th\,,..,___r____,__ 0 ,\.10 A D N i l I n NO. mn =DH NT a I DOWNSTREAM ANALYSIS EXHIBIT i i ligN _ ii a I 0 13 4P i I ,JEi .III . S A CEDAR CREST 1 iiii IIbø A. 4 Kt 5 43 it Q, CiTy of RFNTnA( wARH,Mnrnu Nisi ill 11 DETENTION CALCULATIONS Basin #1, as shown on the Pipe Tributary Area Exhibit in the Appendix, includes the on-site developed areas of Phases 1 and 2 of the project as well as the full width of Edmonds Avenue from N.E. 3' Street to the Hat of La Colina. The specific areas, which were included in the facility sizing calculations, have been summarized in the table below. The table shows the areas calculated for each of the different land covers in the developed condition for the areas tributary to Pond A, the Basin #1 conveyance system, and the Emergency Overflow Pipe. SUMMARY OF AREAS USED IN CALCULATIONS Location Impervious Pervious Pond A Basin#1 Overflow Area Area Sizing Convey- Pipe acres) (acres) ance Sizing CN=98 CN=68 System Sizing' Interior Roads&Sidewalk 7.32 X X X Impervious Area on Lots(2,876 s.f./lot*209 lots)13.80 X X X Edmonds Avenue(On-Site) 1.54 X X X Edmonds Avenue(Off-site) 0.26 X X X R.V.Storage Area 1.94 1.45 X X X Community Center 0.67 0.41 X X X Detention/Infiltration Pond A (Incl.surrounding area) 3.68 X X Water Quality Pond A 0.44 X X Detention/Infiltration Pond B(Incl.in Basin#2 area) 0.61 X Basin#1 Pervious Areas(Lots,landscaping,etc.) 18.65 X X X Bypass Area(Slope in N.E.corner of site)4.30 X Bypass Area(Depression area in N.W.corner of site) 1.47 Off-site Tributary Area(Area along east property line)3.01 X Basin#2 Areas(Includes Pond C and off-site trib.areas) 19.07 21.24 X Acreage Totals 50.16 41.57 97.78 Total Impervious 25.97 22.92 45.04 Total Pervious 24.19 18.65 52.74 Existing Conditions Tributary Area: 50.16 Ac. (area tributary to Pond A)-0.26 Ac. (Edmonds Ave.off-site) 0.61Ac. (Pond B)+4.30 Ac. (N.E. slope bypass area)=54.81 Ac. The totals for this column represent the areas used in the hydrograph flow calculations. For the R.V.Storage and Community Center areas(Impervious: 1.94+0.67=2.61,Pervious: 1.45+0.41 = 1.86),which are also marked with an"X"in this column,the flows were calculated using the Rational Method. The detention calculations were performed using Engenious Systems Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A(User 1) 24-hour rainfall distribution. Separate S.C.S. curve numbers were used for the impervious and pervious portions of the site. Using the onsite existing condition hydrographs, the allowable release rates were determined for the site in accordance with City of Renton standards. Developed condition hydrographs were then generated for the bypass areas in order to verify that the developed bypass flows did not exceed the pre-developed peak runoff rates for each of the 2, 10,and 100-year,24-hour storm events. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 7 Phases 1 & 2 According to Core Requirement #3, Section 1.2.3 of the KCSWDM, "Three basic methods for peak rate runoff control are possible: detention, retention, and infiltration." This project proposes to use infiltration to meet this core requirement. Further in this section of the KCSWDM under the heading `Infiltration Facilities', it states that"the factors of safety for infiltration systems are incorporated within the methods of analysis and design standards described in Section 4.5." In the Hydrogeologic and Geotechnical Services/Report, Geo Engineers, Inc. recommended an effective percolation rate for Pond A of 4 inches per hour. This recommendation was based on the following analysis, which is taken from their report, which is located in the Appendix. "Stormwater infiltration rates for the site soils were calculated based on the grain-size distribution of select soil samples and their corresponding soil textures. The U.S. Department of Agriculture Textural Triangle provided in the Stormwater Management Manual for the Puget Sound Basin, published in February 1992, was used to determine the soil textures and the infiltration rate. Representative soil samples were collected at the elevations of the proposed infiltration pond bottoms below the filter. The theoretical stormwater infiltration rates for the soil samples analyzed is about 8 inches per hour. This rate of infiltration would occur until the underlying soil is saturated and the water table is mounded above the bottom of the pond. When the top of the mound is above the bottom of the pond,the effective infiltration rate is equivalent to the dissipation rate of the mound. Important factors affecting the dissipation are the size and shape of the infiltration area, depth to the water table, and other factors." The report goes on to specifically address the infiltration rate for the area of Pond A(identified in their report as 'area A'). "For area A,the dissipation rate is calculated to be approximately 2 to 21 inches per hour. In order to increase the effective rate to 4 inches per hour, we recommend the construction of a gravel infiltration blanket that extends north of the infiltration pond. The area of the infiltration blackout should be approximately the same as the bottom area of the ponds (76,800 sq.ft.) to provide an effective percolation rate of 4 inches per hour in the pond. We recommend the gravel blanket be 4 feet thick and approximately 100 feet wide. The base of the gravel should be at the same level as the bottom of the filter blanket. Extending the gravel blanket north of pond A (Pond A) to the region where gravel was encountered will significantly increase percolation and provide a margin of safety." Pond A and the connecting gravel filter blanket were constructed by the project owner during the site grading operations that were completed according to the approved Grading/Temporary Erosion and Sedimentation Control plans prepared by Triad Associates (sheets 1 through 21, dated August, 1995 and revised 5/7/98). Verification of the depth, materials, and construction methods used to construct Pond A and the adjoining gravel filter blanket should be provided by the owner to confirm that the facility has been constructed to provide the required infiltrative capacity. The gravel filter blanket was surveyed by the owner's survey crew to be approximately 78,000 sq. ft., and therefore appears adequate to meet the requirements of Geo Engineers' recommended 4 inches per hour effective infiltration rate. Also, this infiltration rate is less than the maximum rate of 8 inches per hour for this Vashon glacial outwash soil as specified in Table 4.5.2 of the KCSWDM. Due to the KCSWDM's Section 4.5 required factor of safety of 2.0 (although the EPA test was not used, 2.0 is the more STORM DRAINAGE REPORT FOR CEDAR CREST—Page 8 Phases 1 &2 conservative of the two factors specified in the KCSWDM), an infiltration rate of 2 inches per hour was used for these detention calculations. Pond A also has been as-built surveyed, providing us with accurate information with regards to its storage capacity. Developed condition hydrographs were generated for each of the 2, 10, and 100-year, 24-hour storm events for the 50.16 acres of area tributary to Pond A. They were then routed through infiltration Pond A, verifying that the volume of the as-built pond was sufficient, as shown in the Level Pool Summary shown below. For the following calculations,the total precipitation for the 2, 10,and 100-year,24-hour storm events were found to be 2.00",2.90",and 3.90"respectively,as shown on the respective King County isopluvials in the Appendix. The curve numbers used for the different landcovers are shown on Table 3.5.2E — S.C.S. Western Washington Runoff Curve Numbers, located in the Appendix. All of these exhibits are located in the Appendix of this report. A summary of the off-site release and detention/infiltration pond calculations is provided below. OFF-SITE RELEASE Onsite Existing Condition Hydrographs Total Area=54.81 Ac(See the preceding Summary of Areas table) Impervious Area = 0.00 Ac @ CN=98 Pervious Area =54.81 Ac @ CN=68 (grassy open space) Time of Concentration=28.69 minutes(See the Times of Concentration Exhibit in the Appendix) Reach 1: 300 ft Sheet Flow @ 8.7%, 'n'=0.15 (grass) Reach 2: 872 ft Shallow Concentrated Flow @ 3.9%,`ks' =5 (grass) Reach 3: 1,088 ft Channel Flow @ 2.8%,`ks'=5 (grassy swale) Existing Condition Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] 2-Year 2.00 0.87 38,693 1440 10-Year 2.90 2.23 114,545 760 100-Year 3.90 7.12 227,252 490 STORM DRAINAGE REPORT FOR CEDAR CREST—Page 9 Phases 1 &2 Bypass Area Developed Condition Hydrographs Slope area along northeast property boundary: Total Area=4.30 Ac(See the Summary of Areas table) Impervious Area =0.00 Ac @ CN=98 Pervious Area =4.30 Ac @ CN=68 (grassy open space) Time of Concentration= 16.23 minutes(See the Times of Concentration Exhibit in the Appendix) Reach 1: 277 ft Sheet Flow @ 6.2%, `n' =0.15 (grass) Reach 2: 616 ft Channel Flow @ 1.5%,`ks' =20(earth-lined ditch) Reach 3: 1,483 ft Channel Flow @ slope varies 0.5%to 2.8%,`ks'=42(pipe) N.E.Bypass Area Developed Condition Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] 2-Year 2.00 0.07 3,036 1440 10-Year 2.90 0.20 8,986 490 100-Year 3.90 0.71 17,829 480 Depression area in northwest corner of property: Total Area= 1.47 Ac(See the Summary of Areas table) Impervious Area =0.00 Ac @ CN=98 Pervious Area = 1.47 Ac @ CN=68 (grassy open space) Time of Concentration= 13.33 minutes(See the Times of Concentration Exhibit in the Appendix) Reach 1: 240 ft Sheet Flow @ 24.6%, `n'=0.24(dense grass) N.W.Depression Area Developed Condition Hydro raph Sununary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] 2-Year 2.00 0.02 1,038 1440 10-Year 2.90 0.07 3,072 490 100-Year 3.90 0.26 6,095 480 Offsite Release Summary Using the existing condition hydrographs,the following allowable release rates for the site were determined. 2-Year Allowable Release Rate =2-yr Pre-developed flow =0.87 cfs 10-Year Allowable Release Rate = 10-yr Pre-developed flow =2.23 cfs 100-Year Allowable Release Rate= 100-yr Pre-developed flow=7.12 cfs The hydrograph sums(not arithmetic sums)for the bypass areas(as shown below) were then compared with the allowable release rates in order to check that the flows discharged from the site in the developed condition did not exceed the allowable rates. Please refer to the Water Works output located in the Appendix for the hydrograph data,hydrograph summary table,and actual program output. 2-Year Bypass Area Release Rate =Sum of developed flow from both areas=0.09 cfs 10-Year Bypass Area Release Rate =Sum of developed flow from both areas=0.27 cfs 100-Year Bypass Area Release Rate=Sum of developed flow from both areas=0.98 cfs STORM DRAINAGE REPORT FOR CEDAR CREST—Page 10 Phases 1 & 2 INFILTRATION POND A Developed Condition Hydrographs for Area Tributary to Pond A Total Area=50.16 Ac(See the preceding Summary of Areas table) Impervious Area =25.97 Ac @ CN=98 Pervious Area =24.19 Ac @ CN=68 (lawn) The following time of concentration figure is based on an approximate flow path from the R.V. Storage Area to Pond A via the proposed conveyance system. Please reference both the Pipe Tributary Area Exhibit (see Appendix) and the Grading & Utility Plans (that accompany this report) for the basis of the following values used in the computation of the time of concentration. Time of Concentration= 12.11 minutes Reach 1: 128 ft Sheet Flow @ 1.2%, `n'=0.011 (pavement) Reach 2: 149 ft Channel Flow @ 1.5%,`ks' =42(pipe) Reach 3: 147 ft Channel Flow @ 1.7%,`ks' =42(pipe) Reach 4: 411 ft Channel Flow @ 0.5%,`ks'=42(pipe) Reach 5: 146 ft Channel Flow @ 1.9%,`ks' =42(pipe) Reach 6: 101 ft Channel Flow @ 2.1%,`ks' =42 (pipe) Reach 7: 106 ft Channel Flow @ 6.5%,`ks' =42(pipe) Reach 8: 80 ft Channel Flow @ 4.4%,`ks'=42 (pipe) Reach 9: 56 ft Channel Flow @ 1.1%,`ks' =42(pipe) Reach 10: 98 ft Channel Flow @ 3.9%,`ks'=42(pipe) Reach 11: 103 ft Channel Flow @ 3.8%,`ks' =42(pipe) Reach 12: 200 ft Channel Flow @ 2.7%,`ks' =42(pipe) Reach 13: 403 ft Channel Flow @ 2.4%,`ks' =42(pipe) Reach 14: 54 ft Channel Flow @ 2.2%,`ks'=42(pipe) Reach 15: 302 ft Channel Flow @ 2.4%,`ks' =42(pipe) Reach 16: 149 ft Channel Flow @ 2.1%,`ks'=42(pipe) Reach 17: 36 ft Channel Flow @ 1.9%,`ks' =42(pipe) Reach 18: 210 ft Channel Flow @ 0.5%,`ks' =42(pipe) Reach 19: 50 ft Channel Flow @ 2.0%,`ks' =42(pipe) Reach 20: 78 ft Channel Flow @ 1.0%,`ks' =42(pipe) Reach 21: 106 ft Channel Flow @ 1.3%,`ks'=42(pipe) Pond A Tributary Area Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] 2-Year 2.00 11.42 184,347 480 10-Year 2.90 18.15 302,134 480 100-Year 3.90 27.48 445,832 480 Infiltration Pond A Level Pool Routing The following level pool table summary represents the results of routing the Pond A tributary area 2, 10, and 100-year hydrographs (for the developed condition) through infiltration Pond A in order to check the adequacy of the constructed pond. Please refer to the Water Works output located in the Appendix for actual program output. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 11 Phases 1 &2 INFILTRATION POND A -LEVEL POOL TABLE SUMMARY Description Inflow Storage Discharge P.Stage Volume Outflow P.Time CFS]ID ID FT]CF] [CFS] [Min] 2 Year Developed 11.42 POND EMOVR 235.05 82,208 1.405 1450 10 Year Developed 18.15 POND EMOVR 238.04 181,525 1.724 1460 100 Year Developed 27.48 POND EMOVR 241.12 305,349 2.086 1460 Live Storage As shown in the Level Pool Summary above,Pond A has a maximum water surface elevation of 241.12 and provides 305,349 cubic-feet of storage at this elevation. Infiltration Pond A has actually been constructed to provide 328,239 cubic feet of storage at the design maximum water surface elevation of 241.60. Additionally, the wet pond portion of Pond A will provide 62,640 cubic-feet of storage between the live- dead interface elevation of 238.60 and the maximum water surface elevation of 241.60. Therefore,Pond A has been constructed to provide 390,879 cubic feet of storage, or 128%of the required storage volume. The storage volumes specified above are based on a live-dead interface elevation of 238.60. The pipe connecting the wet pond and infiltration pond portions of Pond A has already been installed with an upstream invert elevation of 239.89. This invert elevation will control the elevation of the live-dead interface; therefore, utilizing this 24" diameter pipe as installed will reduce the amount of available live storage in the wet pond cells by 25,450 cubic-feet. With the wet pond providing 37,190 cubic-feet of storage between the live-dead interface and the maximum water surface,and the infiltration pond providing 328,239 cubic-feet, Pond A will provide 365,429 cubic-feet of storage. This is 120% of the required storage volume. Therefore, Pond A will still provide more than the required storage volume if the 24" diameter pipe that conveys flows between the wet pond and infiltration pond portions of Pond A remains as installed. However, if at some point in the future, the project owner desires additional storage volume, 25,450 cubic-feet of additional capacity can be gained by lowering the pipe to have a maximum invert elevation of 238.60. Water Quality Water quality will be provided through the use of dead storage. According to King County standards, the required water quality volume is equal to the total runoff from the developed condition 24-hour design storm event using 33%of the 2-year,24-hour precipitation. 0.33)(PZy,)=(0.33)(2.00 in)=0.67 inches Water Quality Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] Water Quality 0.67 3.08 44,787 480 STORM DRAINAGE REPORT FOR CEDAR CREST—Page 12 Phases 1 & 2 The required volume to be used for water quality storage is 44,787 cubic feet. The three celled wet pond portion of Pond A will provide 48,940 cubic feet of water quality storage (from elevation 235.60 to 238.60)when construction is completed(cell 2 and cell 3 have been completed to date). The wet pond is also required to have a surface area of at least 1% of the developed impervious area. The impervious area in the developed condition is 25.97 acres, therefore 0.26 acres (or 11,313 square feet) of wet pond surface area is required. The wet pond will have a surface area at elevation 238.60 of 19,320 square feet when construction is completed. As mentioned above,the pipe connecting the wet pond and infiltration pond portions of Pond A has already been installed with an upstream invert elevation of 239.89,which is 1.29 feet above the design live-dead interface elevation. This invert elevation will control the elevation of the live-dead interface,therefore, utilizing this 24"diameter pipe as installed will increase the amount of dead storage in the wet pond cells by 25,450 cubic-feet and correspondingly also increase the surface area of the wet pond. In summary,based on the design live-dead interface elevation,the wet pond provides more volume and surface area than is required,and based on the as-built survey,it will provide even more surplus volume and area. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 13 Phases 1 & 2 CONVEYANCE CALCULATIONS In accordance with the King County Surface Water Design Manual, the conveyance systems were designed to provide a minimum of six inches of freeboard within each catch basin for the 25-year, 24-hour design storm event. The systems were then checked with the 100-year storm event to ensure that no overtopping occurred. The hydraulic grade line calculations were performed using Eagle Point Software's computer program Storm Sewers. The program determines the flow rate in each pipe and then performs a standard step hydraulic analysis on the pipe network.The methodology used for non-uniform flow analysis is the standard step energy balance. This procedure is used to determine the hydraulic grade line throughout the pipe network and is identical to that used for any open channel water surface profile. The steady state energy equation (Bernoulli equation) is used between upstream and downstream sections of each pipe in the network. The friction slope is then calculated by applying Manning's equation at the upstream and downstream ends and averaging the slope between them. The program then performs three iterations to pinpoint the hydraulic grade line. Computations begin at the most downstream pipe and continue in an upward direction. The 25 and 100-year flows were determined for Basin #1 using Engenious System Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A(User 1)24-hour rainfall distribution. The areas of Basin#1 that are tributary to the conveyance system are summarized in the Summary of Area Calculations table presented earlier in this report. Separate S.C.S. curve numbers were used for the impervious and pervious portions of the basin. The resultant flows were distributed to each catch basin structure, based on the individual area tributary to each structure, as shown on the Pipe Tributary Area Exhibit located in the Appendix. Basin #1 is served by two separate conveyance systems which both discharge to the first wet pond cell of Pond A(cell 1). The West Conveyance System collects stormwater from portions of Road A (Cedar Crest Parkway) and Road F, all of Roads B, C, and D, and from Edmonds Avenue N.E. The East Conveyance System collects stormwater from the remainder of Basin#1. Please refer to the Pipe Tributary Area Exhibit located in the Appendix for more detailed information on the two systems. The conveyance system between Pond C and Pond B is anticipated to be constructed as a part of Phase 1 and 2. However, the analysis for this conveyance system is provided in the"Cedar Crest—Phases III & IV Storm Drainage Report". STORM DRAINAGE REPORT FOR CEDAR CREST—Page 14 Phases 1 & 2 Using Water Works software,the following 25 and 100-year peak flows were determined: Total Areal Area2 Qu Q100 Tailwater Tailwater Area (Acres) (Acres) (CFS) (CFS)Elev. Elev. Acres) 25-Year 100-year West Basin 18.66 1.08 17.58 8.35 10.05 241.21 241.60 East Basin 27.38 3.39 23.99 11.39 13.71 241.21 241.60 These areas(Community Center-West Basin and R.V. Storage Area-East Basin) were included in the conveyance analysis by computing baseflows using the Rational Method and are shown on the Pipe Tributary Area Exhibit as flows(Q). 2 For these areas,the majority of the basin,the area tributary to each catch basin was measured,and then the S.B.U.H. flows for each catch basin were calculated based on each structure's proportionate area.The S.B.U.H. flows for these areas are shown in this table in the adjacent columns,and do not include the flows from the Community Center or R.V. Storage Area. These flows were input into Storm Sewers as individual flows for each catch basin as shown on the Table of Flows Used for H.G.L. Calculations for Each Catchment Area in the Appendix. Due to the fact that both the Community Center and R.V. Storage Areas have greater densities of impervious area than the majority of the basin,25 and 100-year flows were calculated separately for them using the Rational Method,as summarized below. The time of concentration was calculated to be less than the minimum allowed by King County,and so the minimum value of 6.3 minutes was used for these Rational Method calculations. Location Impervious Pervious T, Peak Peak Q25 Qioo Area Area (minutes) Rainfall Rainfall (cfs) (cfs) acres)acres) Intensity Intensity Izs) Iioo) Conununity Center 0.67 0.41 6.30 2.73 3.19 1.93 2.25 R.V.Storage Area 1.94 1.45 6.30 2.73 3.19 5.76 6.73 Q= (C x I x A) The runoff coefficients used in the above equation to obtain the flow values shown in the table above were C=0.25 for all pervious areas(lawns)and C=0.90 for all impervious areas(pavement and roofs). The peak rainfall intensities(I)used in the above equation are provided in the table above and are detailed as follows,where the values for PR and T,were provided previously and aR and bR are per Table 4.3.3B in the KCSWDM(also included in the Appendix): I25=PR x(aR x T,-(b`))= 3.40 x(2.66 x(6.30)465)=2.73 Imo=PR x(aR x T,-(br))= 3.90 x(2.61 x(6.30)043)= 3.19 The flows shown above were then distributed to the catchbasins within each sub-basin based on the area tributary to each structure. This distribution is detailed on the Table of Flows Used for Hydraulic Grade Line Calculations for Each Catchment Area included in the Appendix. The Rational Method flows that were calculated for the 100-year storm event were conservatively used in the hydraulic grade line analysis of the conveyance system for both the 25 and 100-year storm events. These 100-year flows are also shown on the Pipe Tributary Area Exhibit located in.the Appendix. The following are the 25-year and 100-year freeboard tables for the on-site conveyance systems,which show that all of the catch basins have sufficient freeboard. Please refer to the Hydraulic Grade Line Calculations exhibit,in the Appendix of this report,for actual computer output. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 15 Phases 1 & 2 EAST BASIN FREEBOARD TABLE 25-yr and 100-yr Location Catch Rim Elev. HGL Elev. Freeboard HGL Elev. Freeboard Basin ft) 25-yr(ft) 25-yr(ft) 100-yr(ft) 100-yr(ft) Road E CB 2-21A 244.00 241.29 2.71 241.71 2.29 CB 2-21* 242.25 241.37 0.88 241.81 0.44 Road A CB 1-8 242.96 241.45 1.51 241.91 1.05 CB 1-10 245.06 241.57 3.49 242.04 3.02 CB 1-11 245.06 242.46 2.60 242.55 2.51 _ CB 1-12 247.16 244.01 3.15 244.18 2.98 CB 1-12A 247.16 244.21 2.95 244.44 2.72 CB 1-13A 249.38 246.10 3.28 246.25 3.13 CB 1-13 249.14 246.20 2.94 246.39 2.75 CB 3-53* 250.36 247.30 3.06 247.35 3.01 CB 3-55 250.86 247.68 3.18 247.71 3.15 CB 3-56 252.36 249.35 3.01 249.40 2.96 _ Road F CB 1-47* 248.64 246.25 2.39 246.44 2.20 CB 1-48 250.12 247.13 2.99 247.18 2.94 CB 1-50* 252.18 249.14 3.04 249.19 2.99 CB 2-1* 248.65 246.26 2.39 246.46 2.19 CB 2-3* 251.45 248.81 2.64 248.92 2.53 CB 2-5* 255.85 253.07 2.78 253.14 2.71 CB 2-7* 260.42 257.21 3.21 257.27 3.15 CB 2-9* 264.65 261.56 3.09 261.60 3.05 CB 2-11 266.30 262.98 3.32 262.99 3.31 Road H CB 1-51* 246.53 244.01 2.52 244.18 2.35 CB 2-12* 246.49 244.29 2.20 244.54 1.95 CB 2-14* 249.36 246.52 2.84 246.59 2.77 CB 2-16* 253.34 250.32 3.02 250.37 2.97 CB 2-18 254.07 250.98 3.09 251.02 3.05 CB 2-19* 255.64 252.49 3.15 252.52 3.12 Road G CB 2-23* 244.45 242.66 1.79 242.80 1.65 CB 2-25* 247.56 245.72 1.84 245.85 1.71 CB 2-27* 251.19 249.30 1.89 249.42 1.77 CB 2-29 254.83 252.87 1.96 252.98 1.85 CB 2-30* 256.04 254.06 1.98 254.16 1.88 CB 2-32* 260.89 258.82 2.07 258.91 1.98 CB 2-34 265.74 263.55 2.19 263.62 2.12 CB 2-36* 271.08 268.80 2.28 268.85 2.23 CB 2-38 274.98 272.64 2.34 272.68 2.30 CB 2-39* 278.76 276.38 2.38 276.42 2.34 Fire Access Rd. CB 2-40 279.40 276.95 2.45 276.97 2.43 CB 2-41 282.93 280.46 2.47 280.48 2.45 CB 2-42* 289.80 287.30 2.50 287.31 2.49 CB 2-45 296.66 289.36 7.30 289.37 7.29 R.V.Stg.Area CB 2-46 295.86 292.47 3.39 292.47 3.39 CB 2-47 297.06 293.07 3.99 293.07 3.99 CB 2-48 296.07 293.54 2.53 293.54 2.53 CB 2-49 297.73 294.46 3.27 294.46 3.27 CB 2-50 299.23 297.01 2.22 297.01 2.22 CB 2-51 300.81 298.93 1.88 298.93 1.88 Road G CB 1-53* 244.33 241.92 2.41 242.36 1.97 Road E CB 1-55* 242.45 241.45 1.00 241.92 0.53 Inlets were not modeled. The inlets of the main line were not modeled because the main line generally had in excess of 1 ft of freeboard for the 25-year event. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 16 Phases 1 & 2 WEST BASIN FREEBOARD TABLE 25-yr and 100-yr Location Catch Basin Rim Elev. HGL Elev. Freeboard HGL Elev. Freeboard ft) 25-yr(ft) 25-yr(ft) 100-yr(ft) 100-yr(ft) Pond#1 CB EX. 244.00 241.26 2.74 241.66 2.34 Comm.Center CB 1-1 243.35 241.29 2.06 241.70 1.65 CB 1-2 242.73 241.31 1.42 241.73 1.00 Road A CB 1-3 243.07 241.33 1.74 241.76 1.31 CB 1-5 243.06 241.35 1.71 241.79 1.27 Road C CB 1-26 242.10 241.37 0.73 241.82 0.28 INLET 1-27 242.10 241.37 0.73 241.82 0.28 CB 1-28 242.84 241.38 1.46 241.84 1.00 CB 1-29* 244.30 241.80 2.50 241.88 2.42 CB 1-31* 247.95 244.77 3.18 244.80 3.15 Road F CB 1-33* 242.53 241.41 1.12 241.88 0.65 CB 1-35 245.73 242.78 2.95 242.87 2.86 CB 1-42* 248.95 245.95 3.00 246.00 2.95 CB 1-44* 253.00 249.89 3.11 249.93 3.07 Road D CB 1-36* 245.62 243.14 2.48 243.21 2.41 CB 1-38* 248.20 245.23 2.97 245.29 2.91 CB 1-40* 251.53 248.35 3.18 248.38 3.15 Road A CB 1-7 242.38 241.33 1.05 241.76 0.62 CB 1-4 245.66 242.06 3.60 242.18 3.48 Road B CB 1-14* 245.06 242.81 2.25 242.95 2.11 CB 1-16* 246.46 244.12 2.34 244.24 2.22 CB 1-18* 248.86 246.77 2.09 246.90 1.96 CB 1-20 249.17 246.91 2.26 247.09 2.08 CB 1-21 249.46 247.01 2.45 247.23 2.23 CB 1-22* 251.86 248.60 3.26 248.68 3.18 CB 1-24* 254.26 251.27 2.99 251.33 2.93 Road A CB 1-6 242.38 241.35 1.03 241.79 0.59 Comm.Center CB EX. 245.00 241.32 3.68 241.75 3.25 CB EX. 247.00 241.50 5.50 241.83 5.17 Edmonds Ave. CB 7 255.35 252.56 2.79 252.64 2.71 CB 8 255.34 252.63 2.71 252.71 2.63 CB 9* 282.35 279.41 2.94 279.47 2.88 CB 11* 296.64 292.16 4.48 292.20 4.44 CB 13 306.43 303.05 3.38 303.08 3.35 CB 14 306.43 303.13 3.30 303.15 3.28 LA COLINA 311.25 307.37 3.88 307.38 3.87 CB 1 247.50 244.42 3.08 244.45 3.05 CB 2* 248.10 244.99 3.11 245.03 3.07 CB 3 252.28 247.60 4.68 247.62 4.66 CB 4* 264.39 261.06 3.33 261.08 3.31 Comm.Center CB 1-lA 242.73 241.30 1.43 241.72 1.01 Inlets were not modeled. The inlets of the main line were not modeled because the main line generally had in excess of 1 ft of freeboard for the 25-year event. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 17 Phases 1 & 2 EMERGENCY OVERFLOW PIPE CONVEYANCE CALCULATIONS In accordance with the King County Surface Water Design Manual, the Emergency Overflow conveyance system is required to provide a minimum of six inches of freeboard within each catch basin for the 25-year, 24-hour design storm event. Additionally, while conveying the 100-year, 24-hour design storm event, overtopping of any of the catch basins is not allowed. As designed,the emergency overflow pipe was sized to provide a minimum of six inches of freeboard within each catch basin while conveying the 100-year,24- hour design storm flows from both basins simultaneously. This was done to ensure that if both of these infiltration facilities were to fail,the flow could be adequately discharged off site to the natural downstream discharge point. For this analysis, hydrographs were developed using S.B.U.H. methodology,just as in the previous sections of this report. The hydrographs were created for the tributary areas of each basin separately, as summarized in the Summary of Area Calculations table presented earlier in this report and as shown on the Pipe Tributary Area Exhibit located in the Appendix. The computer program Storm Sewers was used to perform the actual hydraulic gradeline computations, following the same procedures used to check the adequacy of the primary conveyance system. The Emergency Overflow Pipe was analyzed for a theoretical failure scenario of the entire flow of Basin#1 being discharged at the outlet of Pond A while the entire flow of Basin #2 is discharged at the outlet of Pond C (Phases 3 and 4). Additionally, the entire flow being contributed to Pond B from Pond C was assumed to be entering the overflow pipe from Pond B. Therefore, the Pond B flow was accounted for twice, in order to conservatively verify the Emergency Overflow Pipe's ability to handle the overflow created by a failure occurring simultaneously in both Pond C and the discharge pipe from Pond C to Pond B. For this analysis,flow was also contributed from the bypass areas consisting of the slopes along the east side of the site and the offsite(upstream)tributary area along the east property line. The flows used for this hydraulic grade line analysis are detailed in the following table, which also lists the acreages of each tributary area. The tailwater elevation shown is the approximate elevation of the natural pond/stream at the discharge point of the Emergency Overflow Pipe in the northwest corner of the site. Area QIN Tailwater Elev. Acres) (CFS) Basin#1 50.16 27.48 223.00(Outfall at off-site discharge point) Basin#1 Off-site Tributary Area 3.01 0.50 223.00(Outfall at off-site discharge point) Basin#1 N.E.Slope Bypass Area 4.30 0.71 223.00(Outfall at off-site discharge point) Basin#2 39.36 17.71 223.00(Outfall at off-site discharge point) Basin#2 Off-site Bypass Area 0.95 0.14 223.00(Outfall at off-site discharge point) Basin#2 Pond B Discharge N/A 1.02 223.00(Outfall at off-site discharge point) STORM DRAINAGE REPORT FOR CEDAR CREST—Page 18 Phases 1 &2 The following is the 100-year freeboard table for the Emergency Overflow Pipe, which summarizes the amount of freeboard available in each structure. The table shows that all of the catch basins have sufficient freeboard. Since sufficient freeboard is present for the 100-year event, the 25-year event was not included in the analysis. Please refer to the Hydraulic Grade Line Calculations exhibit, in the Appendix of this report,for actual computer output. FREEBOARD TABLE 100-yr Catch Basins Rim Elev. HGL Elev. Freeboard ft)100-yr(ft) 100-yr(ft) CB OV-1 243.71 224.43 19.28 CB OV-2 244.64 226.25 18.39 CB OV-3 242.39 228.08 14.31 CB OV-4** 242.40 233.66 8.74 CB OV-5** 246.09 238.58 7.51 CB OV-6 250.90 243.33 7.57 CB OV-7 252.30 244.39 7.91 POND C OVERFLOW 250.80 245.01 5.79 POND A OVERFLOW 241.00 239.31 1.69 POND B OVERFLOW 246.00 239.66 6.34 I These catch basins were numbered sequentially to make their order clearer. However,the plan set designations are different from the labels shown here. Indicates a junction between a branch and the main line. EROSION CONTROL Grading/Temporary Erosion and Sedimentation Control Plans were prepared by Triad Associates in August 1995 and revised May 7, 1998. These plans, that were approved by the City of Renton, were designed to satisfy the erosion and sedimentation control requirements from initial grading through final build out. 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' ,ip. 1 r--,.\,......_ .)4gD,," • . asigy NA i. :,-...0\ -... IT'OK s..... if-3.1'1,-••••-• --., s"------•--. __- -- I A ...1 %;------ i....i• ' '?;.. - , VI itiici...2"' if I..1.__•1-• 11 ' % . "• , -'•-• At 93 ito k.0 r..,q... • • •.......,.. --.. tt e•- . , - •I,,7..... ..ti -mi I::I; . :1! i...it ••'•4•21. L.?' .-......- • -i .,. t. 0. • SCS SOILS MAP KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.2B SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) 1 Runoff curve numbers for selected agricultural, suburban and urban land use for Type 1A rainfall distribution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION AB CD Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land:undisturbed or older second growth 42 64 76 81 Wood or forest land:young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area 68 80 86 90 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 98 Open water bodies: lakes, wetlands, ponds, etc. 0 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, impervious condominiums, apartments, must be computed commercial business and industrial areas. 1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. 2) Assumes roof and driveway runoff is directed into street/storm system. 3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 3.5.2-3 11/92 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1C 2-YEAR 24-HOUR ISOPLUVIALS 4 - Irtillify$fttiplili T l0e1i0m7 .- I.i,t, pee I/. :4i1Ei14. i:fir...t 0im t, 1. Tin- lnti % atv. F.ri wi.ei\. T A mAmv4,iallrakk-. k,.sre., 3t8i-6g1irlil % mar.1- , :-,* .*mhoi \. . / . ,9 iiiI L E r w Nrif i 240 gll\MW-, ilki itITAINkilg1r( `0111/1 C .I I a -'% fs NItit....„. 1 1,..t....„„0.6._ „,.. . . 1 -e.,,,, 44.tliiiM 4--Y Neryititt am o, :." /1 tolp& yriirrlorObri"..1 13VT"'40N ikci‘ .501==.,.....:.,_ __ l 1 • Y t • ii,- ;IP/ r/`At -,i 1••.-.n c = - o, Alma, . i •Itiv1114,i 110ifftwt ' A rlAsti i-er---,10,0ar As4i. -* ip ,itilir,\ , 0--g, Ay' ....=, kiffy. n_, milt A\\ ., --_,Awir..:N, wc-- Ni •" ; e SITEV4AL . ew :0"-'C AI•=416, v. wk! Via yakfell .- \NNk. \ (1111111 ' 4- 41 Vtalierldll Q.:A.. 11146, ‘ - 4 nut= ..- muwatiaripoir -r \ , 7te 1 • i J' tedise . 411 wig ... *ficill i A ‘ 4-p., - Vali Pill 55-01111 trip--14;i14.411...EAMPritlIediA N 1 0 Ordilildir7IMMEM".i01111eii ( 14 o ellEri7 _ 7111111k 0. )9F, —"II, l[I nar N. regi o 9erliIA,Wsian--mi Prig 4,, Ir_i;_t_ . r?'. • , eli ' .,,,__. -7.--f. ------ --: . IPA p •i; - ' 2-YEAR 24-HOUR PRECIPITATION liiinfIPIN1 3.4' ISOPLUVIALS OF 2-YEAR 24-HOUR VI rel I -TOTAL PRECIPITATION IN INCHES V r 0 1 2 3 4 5 6 7 8 Mlles r • c .Ai y-••-I fr- r 1/91:300,000 3.5.1-8 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1E 10-YEAR 24-HOUR ISOPLUVIALS 21 22 ., s w.3 A 27 -. f.i;t:dN ib : i4RK 0 IgiViIil„ 1 W 0'v,l 10 I •I', N17-. 4r,IV4Ikoiy1114*41W-- v I P a° \ .*- :- \ ' C.Rilgiii5V INIFINftliMirijil ' ilfr171e,„, \nKtilS I 1'‘11211T0111114010,11111 1ga I1 ,V Ito. 31 r 1 440.1 1:4,-.4; a 6 'tr. % .viggi., _' wk.‘ I-.1 ''Iw- lir- Vicit*ii/ Illitk N r' '‘.., k ' N'...t .-- 1 Takirt . 1 -N4119 4041,n1004/. ff .di‘_ 3.Z 1 ail' fritr‘— cj A ‘ fiiiii _ tit/ Air -4110\43;i1\ I ( -"/ IPA, " 1 ..AP1611.1 ;33 if ','"-- - \ ISIS -S I T E - 410416 - i& klk litili . rjAil k--•Tis‘‘,.,, .),‘, - 4 i' It_ 4 jai IV%*a".11V11110 t N\ y jAg .. -% ,01144"41151111 k i .!-'11111111ks , -. a ppird all It 4'. N ' Ar il.:1 "lifiii-`,...--- \ lailillidnill A AL.Amk i 161gpb,. El. #ifinFINIMPat Vogt Prialli. 1nalffilk_.__=94111511,1 i t„I OOPS Wileillilirmirk fitv. --\_J-11,4111tig i w‘aftsmatikiNi jr.Serifie-Wir N: _. - - 1 )-`-V T rrk JAMIrE14,11110*F OF . II 404Pf ail" 'r kr , Nii cip (cm . .. 4,,,, tmerii.ii liV F \ '• Cre' 7 0014144* l i , 1 0-YEAR 24-HOUR PRECIPITATION r "'`! TIL3.4 ISOPLUVIALS OF 10-YEAR 24-HOUR ft" r , TOTAL PRECIPITATION IN INCHES 3QINV MEWti 0 1 2 3 4 5 6 7 8 Mlles A 1 ' 1:300,000 3.5.1-10 s 1/90 4.1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1F 25-YEAR 24-HOUR ISOPLUVIALS 411-11q. - *1; 41/- iiiiiiii; - ---. z''.;--. ----- - ,..--------7- - ----c7.-- . ft . 111' ':7Y147.4.--N, .it 1-0411-N-j v< sizralogattelitiZihisi Awitieto- 9 ' IltitrA Ale,ALAWP Witialit , . 4 3.0 . 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S4 itii 44 r- 4liMgr* •1 7i -=ft.1 v rills A11111FLlieldri, j Vint1101 25-YEAR 24-HOUR PRECIPITATION op w rAr ai ss 4 ISOPLUVIALS OF 25-YEAR 24-HOUR h Ams AI r , 4 TOTAL PRECIPITATION IN INCHES ny to 7Fra S O 1 2 3 4 5 6 7 8 Mlles n„. co O 3,", -- 3.5.1-11 lb' tr 1/90 1:300,000 KING COUNTY, WAS HINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3S.1H 100-YEAR 24-HOUR ISOPLUVIALS 3. 3?------ Vtgliar/647 ,40,;- IV-- - . ' -7----- ;..-i,---------- -- , N - b4 411 Ifillfeilvr wpmAl ,/,' 11111116bAr' gm 4 Vt 441W 4LA% vg&I , 3 3 . 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Sk\\V\\441 i liggieL _ c',-.,;, • lin% 42 III 411 ‘4\ ‘: ‘,"4.. w 1 al r-- k,1 Wiliallliir Illikv Itolo 7rog Milleal 4 ti 1 1iSP°16,41 ; -( i /I/ 41P laTin lif.jE r it y_ ififiliplik e.._,i1H11 I in 04affreggli 61 4...-warix .Thalitirm ilt L-4 i11.4y1Xlielk itifitiPfilp s ..1-- FaIRIPP ,PA-41.1.mirimmits„..._.,406 iiiiii ,__ rivistA friaii.,_. 4-Alaw 4wInk. -4 4.ililik‘ IK' ' Ar 1,r4 111 11-Atwzrf .7 iv - ItiogiVA rb Cb . IPA ' ,_. '' lrir fi 1 10, IC11. 100-YEAR 24-HOUR PRECIPITATION y refsria1 6.6 ISOPLUVIALS OF 100-YEAR 24-HOUR 0O N ANOCIANI.Pli AINCHESrfb- '/ 5.5 TOTAL PRECIPITATION IN 0i 0 1 2 3 4 5 6 7 8 Mlles 3.5.1-13 y0 d 1:300,000 1/90 c„n„:•••• ,. .::: • ,•••••,....., \\ \ XX d eF.V e ems' i'..N-sZ•• 2..•'•%. I fi / ,„%',,i„..1'./.-1 i ` 1 r f{fV, .lp j:i '§7 r I 1----rt-r) \ ; ai,i:::!;:g;,1 1 itii i ; ....,„........> ;,..,<.,-nr.;!•i:.',. fi!' sile>2sY'.• ti mow.. yp l 1 r1 1 ,/// : `. .Y ' f,.•......... 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'S. n • IV If, 3 .l V, ! ii i ., pi s , 1 e cC t„. ., V+ T CO to40 VV11II 7FS,. i- r+ , rry7{ ysut s Dk `f.. 0 i cn o o tn o 110• DOI UPLSION ITa TIMES OF CONCENTRATION EXHIBIIT t BASIN 1 6 111ilL CEDAR CREST Itfiø' co li pp 0 CITY AA- CFUTnaI WASNlNGTON N BASIN SUMMARY BASIN ID: Al NAME:2-YR EXISTING SBUH METHODOLOGY TOTAL AREA..: 54.81 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.00 inches AREA..: 54.81 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 28.69 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 TcReach-Sheet L: 300.00 ns:0.1500 p2yr:2.00 s:0.0870 TcReach-Shallow L: 872.00 ks:11.00 s:0.0390 TcReach-Channel L:1088.00 kc:20.00 s:0.0280 PEAK RATE: 0.87 cfs VOL: 0.89 Ac-ft TIME: 1440 min BASIN ID: A2 NAME: 10-YR EXISTING SBUH METHODOLOGY TOTAL AREA..: 54.81 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 2.90 inches AREA..: 54.81 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 28.69 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 2.23 cfs VOL: 2.63 Ac-ft TIME: 760 min BASIN ID: A3 NAME: 100-YR EXISTING SBUH METHODOLOGY TOTAL AREA..: 54.81 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 54.81 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 28.69 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 7.12 cfs VOL: 5.22 Ac-ft TIME: 490 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 1 Phases 1 &2 BASIN SUMMARY BASIN ID:B1 NAME: 2-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.00 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 11.42 cfs VOL: 4.23 Ac-ft TIME: 480 min BASIN ID:B2 NAME: 10-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.90 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 18.15 cfs VOL: 6.94 Ac-ft TIME: 480 min BASIN ID:B3 NAME: 100-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 27.48 cfs VOL: 10.23 Ac-ft TIME: 480 min BASIN ID:B4 NAME: 25-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.40 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 22.70 cfs VOL: 8.55 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 2 Phases 1 & 2 BASIN SUMMARY BASIN ID:WQ NAME:WATER QUALITY HYDROGRAPH SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 0.67 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 3.08 cfs VOL: 1.03 Ac-ft TIME: 480 min BASIN ID:Cl NAME:MAIN CONVEYANCE SYS. -25 YR SBUH METHODOLOGY TOTAL AREA..: 41.57 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USERI PERVIOUS AREA PRECIPITATION..: 3.40 inches AREA..: 18.65 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 22.92 Acres CN..: 98.00 PEAK RATE: 19.74 cfs VOL: 7.36 Ac-ft TIME: 480 min BASIN ID:C2 NAME:MAIN CONVEYANCE SYS.- 100 YR. SBUH METHODOLOGY TOTAL AREA..: 41.57 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 18.65 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 22.92 Acres CN..: 98.00 PEAK RATE: 23.76 cfs VOL: 8.78 Ac-ft TIME: 480 min BASIN ID: E3 NAME:OFF-SITE TRIBUTARY- 100 YR. SBUH METHODOLOGY TOTAL AREA..: 3.01 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER! PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 3.01 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.50 cfs VOL: 0.29 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 3 Phases 1 &2 BASIN SUMMARY BASIN ID:4-2 NAME: BASIN 1 -E.SLOPE BYPASS 2 YR SBUH METHODOLOGY TOTAL AREA..: 4.30 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.00 inches AREA..: 4.30 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 TcReach-Sheet L:277.00 ns:0.1500 p2yr: 2.00 s:0.0620 TcReach-Shallow L: 616.00 ks:20.00 s:0.0150 TcReach-Channel L:309.00 kc:42.00 s:0.0280 TcReach-Channel L:175.00 kc:42.00 s:0.0250 TcReach-Channel L:371.00 kc:42.00 s:0.0120 TcReach-Channel L:340.00 kc:42.00 s:0.0270 TcReach-Channel L:288.00 kc:42.00 s:0.0050 PEAK RATE: 0.07 cfs VOL: 0.07 Ac-ft TIME: 1440 min BASIN ID:4-10 NAME: BASIN 1 -E. SLOPE BYPASS 10 Y SBUH METHODOLOGY TOTAL AREA..: 4.30 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER! PERVIOUS AREA PRECIPITATION..: 2.90 inches AREA..: 4.30 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.20 cfs VOL: 0.21 Ac-ft TIME: 490 min BASIN ID:4-100 NAME: BASIN 1 -E.SLOPE BYPASS 100 SBUH METHODOLOGY TOTAL AREA..: 4.30 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 4.30 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.71 cfs VOL: 0.41 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 4 Phases 1 &2 BASIN SUMMARY BASIN ID: 5-2 NAME: BASIN 1 -DEP. BYPASS 2 YR. SBUH METHODOLOGY TOTAL AREA..: 1.47 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.00 inches AREA..: 1.47 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 13.33 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 TcReach-Sheet L:240.00 ns:0.2400 p2yr: 2.00 s:0.2458 PEAK RATE: 0.02 cfs VOL: 0.02 Ac-ft TIME: 1440 min BASIN ID: 5-10 NAME: BASIN 1 -DEP. BYPASS 10 YR. SBUH METHODOLOGY TOTAL AREA..: 1.47 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.90 inches AREA..: 1.47 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 13.33 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.07 cfs VOL: 0.07 Ac-ft TIME: 490 min BASIN ID: 5-100 NAME: BASIN 1 -DEP.BYPASS 100 YR. SBUH METHODOLOGY TOTAL AREA..: 1.47 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 1.47 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 13.33 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.26 cfs VOL: 0.14 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 5 Phases 1 &2 BASIN ID: 2-100 NAME:BASIN 2- 100-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 17.71 cfs VOL: 7.76 Ac-ft TIME: 480 min BASIN ID:2-OS1 NAME: BASIN 2—OFF SITE BYPASS— 100 YR. SBUH METHODOLOGY TOTAL AREA..: 0.95 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 0.95 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.14 cfs VOL: 0.09 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST—Page 6 Phases 1 &2 HYDROGRAPH SUMMARY HYD HYDROGRAPH DESCRIPTION PEAK TIME VOLUME AREA NUM. CFS] Min] CF] Ac] 1 EXISTING CONDITIONS—BASIN#1 —2 YR. 0.868 1440 38,693 54.81 2 EXISTING CONDITIONS—BASIN#1 — 10 YR. 2.229 760 114,545 54.81 3 EXISTING CONDITIONS—BASIN#1— 100 YR. 7.125 490 227,252 54.81 5 DEVELOPED CONDITIONS—BASIN#1 —2 YR. 11.420 480 184,347 50.16 6 DEVELOPED CONDITIONS—BASIN#1 — 10 YR. 18.152 480 302,134 50.16 7 DEVELOPED CONDITIONS—BASIN#1 — 100 YR. 27.484 480 445,832 50.16 8 DEVELOPED CONDITIONS—BASIN#1 —25 YR. 22.705 480 372,633 50.16 9 WATER QUALITY EVENT—BASIN#1 3.077 480 44,787 50.16 10 OUTFLOW OF POND A BY INFILTRATION—2 YR. 1.405 1450 184,347 50.16 11 OUTFLOW OF POND A BY INFILTRATION— 10 YR. 1.724 1460 257,846 50.16 12 OUTFLOW OF POND A BY INFILTRATION—25 YR. 1.905 1460 283,167 50.16 13 OUTFLOW OF POND A BY INFILTRATION— 100 YR. 2.086 1460 308,393 50.16 14 BASIN#1 CONVEYANCE SYSTEM—25 YR. 19.736 480 320,602 41.57 15 BASIN#1 CONVEYANCE SYSTEM— 100 YR.23.760 480 382,282 41.57 16 OFF-SITE TRIBUTARY AREA FLOW— 100 YR. 0.499 480 12,480 3.01 18 BASIN#2— 100 YR.FLOWS 17.706 480 337,856 39.36 19 BASIN#2— 100 YR. OFF-SITE BYPASS AREA 0.140 480 3,939 0.95 20 BASIN#2— 100 YR.ORIFICE DISCH.TO POND B 1.021 1460 102,500 0.00 B-1 BYPASS AREA—N.E.SLOPE—2 YR. 0.069 1440 3,036 4.30 B-2 BYPASS AREA—N.E.SLOPE— 10 YR. 0.201 490 8,986 4.30 B-3 BYPASS AREA—N.E. SLOPE— 100 YR. 0.713 480 17,829 4.30 B-4 BYPASS AREA—N.W.DEPRESSION—2 YR. 0.023 1440 1,038 1.47 B-5 BYPASS AREA—N.W.DEPRESSION— 10 YR. 0.073 490 3,072 1.47 B-6 BYPASS AREA—N.W.DEPRESSION— 100 YR. 0.262 480 6,095 1.47 B-7 SUM OF BYPASS AREA HYDROGRAPHS—2 YR. 0.092 1440 4,073 5.77 B-8 SUM OF BYPASS AREA HYDROGRAPHS— 10 YR. 0.274 490 12,058 5.77 B-9 SUM OF BYPASS AREA HYDROGRAPHS— 100 YR. 0.975 480 23,923 5.77 WATER WORKS OUTPUT FOR CEDAR CREST—Page 7 Phases 1 & 2 STAGE STORAGE TABLE TRAPEZOIDAL BASIN ID No.POND Description: INFII..POND-BASIN 1 Length: 155.00 ft. Width: 155.00 ft. Side Slope 1: 3 Side Slope 3: 3 Side Slope 2: 3 Side Slope 4: 3 Infiltration Rate: 30.00 min/inch STAGE STORAGE STORAGE FT] CF] Ac-FT] 232.00 0 0.0000 232.50 12247 0.2811 233.00 24967 0.5732 233.50 38171 0.8763 234.00 51866 1.1907 234.50 66063 1.5166 235.00 80769 1.8542 235.50 95995 2.2037 236.00 111748 2.5654 236.50 128039 2.9394 237.00 144875 3.3259 237.50 162267 3.7251 238.00 180222 4.1373 238.50 198751 4.5627 239.00 217861 5.0014 239.50 237563 5.4537 240.00 257864 5.9197 240.50 278775 6.3998 241.00 300303 6.8940 241.50 322459 7.4026 241.60 326966 7.5061 STAGE DISCHARGE TABLE RISER DISCHARGE ID No.EMOVR Description:EMERGENCY OVERFLOW PIPE Riser Diameter(in): 24.00 elev: 241.60 ft Weir Coefficient...: 3.782 height: 241.60 ft Orif Coefficient...: 9.739 increm: 0.10 ft STAGE DISCHARGE FT] CFS] 241.60 0.0000 WATER WORKS OUTPUT FOR CEDAR CREST-Page 8 Phases 1 &2 LEVEL POOL TABLE SUMMARY Description Inflow Storage Discharge P. Stage Volume Outflow P.Time CFS] ID ID FT]CF]CFS] [Min] DEVELOPED-2 YR 11.42 POND EMOVR 235.05 82,208 1.405 _ 1450 DEVELOPED- 10 YR 18.15 POND EMOVR 238.04 181,525 1.724 1460 DEVELOPED-25 YR 22.70 POND EMOVR 239.61 242,016 1.905 1460 DEVELOPED- 100 YR 27.48 POND EMOVR 241.12 305,349 2.086 1460 WATER WORKS OUTPUT FOR CEDAR CREST—Page 9 Phases 1 & 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 1R" Peak Rainfall Intensity The peak rainfall intensity (IR) for the specified return frequency (R) design storm is determined using a unit peak rainfall intensity factor (is) for a given return frequency (R) design storm using the following equation: IR = (PR)OR) where: PR is the total precipitation at the project site for the 24-hour duration design storm event for the given return frequency (from the Isopluvial Maps in Figures 3.5.1C through 3.5.1H) iR aR)(Tc) ( bR) ; the unit peak rainfall intensity factor Where Tc time of concentration (minutes), calculated using the method described below only (Tc minimum value is 6.3 minutes) aR and bR are coefficients (from Table 4.3.3B) used to adjust the equation for the design storm return frequency (R) This "iR" equation was developed by SWM Division staff from equations originally developed by Ron Mayo, P.E.. It is based on the original Renton/Seattle Intensity/Duration/Frequency (I.D.F.) curves. Rather than requiring a family of curves for various locations in King County this equation adjusts proportionally the Renton/Seattle I.D.F. curve data by using the 24-hour duration total precipitation isopluvial maps. This adjustment is based on the assumption that the localized geo-climatic conditions that control the total volume of precipitation at a specific location also control the peak intensities proportionally. Figure 4.3.3A has been included to demonstrate that this unit peak rainfall intensity (iR) will generate a curve with the same characteristics as the historic 25 year I.D.F. curve. Note, Tc must not be less than 6.3 minutes or greater than 100 minutes. On the historic I.D.F. curves the lower limit was set at 5 minutes, 6.3 minutes was selected based on the mathematical limits of the equation coefficients. TABLE 4.3.3E COEFFICIENTS FOR THE RATIONAL METHOD "iq" -EQUATION DESIGN STORM RETURN FREQUENCY (YEARS) aR bR 2 Year 1.58 0.58 5 Year 2.33 0.63 10 Year 2.44 0.64 25 Year 2.66 0.65 50 Year 2.75 0.65 100 Year 2.61 0.63 4.3.3-3 1/90 TABLE OF FLOWS USED FOR HYDRAULIC GRADE LINE CALCULATIONS FOR EACH CATCHMENT AREA BASIN 1 TOTAL SBUH FLOWS: Q(25)= 19.74 Q(100)=23.76 BASIN 1 TOTAL AREA(AC.): 41.57 Q(25) Q(100) EAST BASIN AREA PERCENTAGE: 57.7%11.39 13.71 WEST BASIN AREA PERCENTAGE: 42.3%8.35 10.05 TOTALS= 19.74 23.76 EAST BASIN SBUH FLOWS:Q(25)= 11.39 Q(100)= 13.71 TOTAL TRIBUTARY AREA(AC.): 23.99 ADD'L.RATIONAL LINE CB# AREA OF TOTAL AREA O(25) Q(100) METHOD FLOWS 1 2-21A 0.00 0.00%0.00 0.00 2 2-21 0.64 2.67%0.30 0.37 3 1-8 0.00 0.00%0.00 0.00 4 1-10 0.00 0.00%0.00 0.00 5 1-11 0.00 0.00%0.00 0.00 6 1-12 0.00 0.00%0.00 0.00 7 1-12A 0.00 0.00%0.00 0.00 8 1-13A 0.00 0.00%0.00 0.00 9 1-13 0.00 0.00%0.00 0.00 10 3-53 0.11 0.46%0.05 0.06 11 3-55 0.05 0.21%0.02 0.03 12 1-47 0.82 3.42%0.39 0.47 13 1-48 0.25 1.04%0.12 0.14 14 1-50 1.24 5.17%0.59 0.71 15 2-1 0.68 2.83%0.32 0.39 16 2-3 1.05 4.38%0.50 0.60 17 2-5 0.92 3.83%0.44 0.53 18 2-7 0.83 3.46%0.39 0.47 19 2-9 0.77 3.21%0.37 0.44 20 2-11 0.20 0.83%0.09 0.11 21 1-51 0.62 2.58%0.29 0.35 22 2-12 0.74 3.08%0.35 0.42 23 2-14 1.03 4.29%0.49 0.59 24 2-16 0.37 1.54%0.18 0.21 25 2-18 0.26 1.08%0.12 0.15 26 2-19 0.71 2.96%0.34 0.41 27 2-23 0.73 3.04%0.35 0.42 28 2-25 0.78 3.25%0.37 0.45 29 2-27 0.94 3.92%0.45 0.54 30 2-29 0.32 1.33%0.15 0.18 31 2-30 1.21 5.04%0.57 0.69 32 2-32 1.66 6.92%0.79 0.95 33 2-34 1.19 4.96%0.57 0.68 34 2-36 0.81 3.38%0.38 0.46 35 2-38 0.42 1.75%0.20 0.24 36 2-39 0.97 4.04%0.46 0.55 37 2-40 0.23 0.96°k 0.11 0.13 38 2-41 0.31 1.29%0.15 0.18 39 2-42 0.36 1.50%0.17 0.21 40 2-45 0.40 1.67%0.19 0.23 41 2-46 0.00 0.00%0.00 0.00 1.56 42 2-47 0.00 0.00%0.00 0.00 0.34 43 2-48 0.00 0.00%0.00 0.00 2.36 44 2-49 0.00 0.00%0.00 0.00 0.95 45 2-50 0.00 0.00%0.00 0.00 0.94 46 2-51 0.00 0.00%0.00 0.00 0.58 47 1-53 0.70 2.92%0.33 0.40 48 1-55 0.54 2.25%0.26 0.31 49 3-56 1.13 4.71%0.54 0.65 SUM TOTALS: 23.99 100.00% 11.39 13.71 6.73 STORM DRAINAGE REPORT FOR CEDAR CREST Phases 1 and 2 TABLE OF FLOWS USED FOR HYDRAULIC GRADE LINE CALCULATIONS FOR EACH CATCHMENT AREA WEST BASIN SBUH FLOWS:Q(25)= 8.35 Q(100)= 10.05 TOTAL TRIBUTARY AREA(AC.): 17.58 ADD'L.RATIONAL LINE CB# AREA OF TOTAL AREA Q(25) Q(100) METHOD FLOWS 1 EX-24 0.00 0.00%0.00 0.00 2 1-1 0.00 0.00%0.00 0.00 0.20 3 1-2 0.00 0.00%0.00 0.00 0.91 4 1-3 0.11 0.63%0.05 0.06 5 1-5 0.00 0.00%0.00 0.00 6 1-26 0.29 1.65%0.14 0.17 7 1-27 0.04 0.23%0.02 0.02 8 1-28 0.15 0.85%0.07 0.09 9 1-29 0.83 4.72%0.39 0.47 10 1-31 0.61 3.47%0.29 0.35 11 1-33 0.48 2.73%0.23 0.27 12 1-35 0.37 2.10%0.18 0.21 13 1-42 0.53 3.01%0.25 0.30 14 1-44 0.89 5.06%0.42 0.51 15 1-36 0.52 2.96%0.25 0.30 16 1-38 1.02 5.80%0.48 0.58 17 1-40 0.62 3.53%0.29 0.35 18 1-7 0.10 0.57%0.05 0.06 19 1-4 0.07 0.40%0.03 0.04 0.43 20 1-14 0.91 5.18%0.43 0.52 21 1-16 1.10 6.26%0.52 0.63 22 1-18 0.57 3.24%0.27 0.33 23 1-20 0.75 4.27%0.36 0.43 24 1-21 0.73 4.15%0.35 0.42 25 1-22 1.38 7.85%0.66 0.79 26 1-24 1.50 8.53%0.71 0.86 27 1-6 0.20 1.14%0.09 0.11 28 EX. 0.00 0.00%0.00 0.00 29 EX. 0.00 0.00%0.00 0.00 30 7 0.55 3.13%0.26 0.31 31 8 0.46 2.62%0.22 0.26 32 9 0.73 4.15%0.35 0.42 33 11 0.60 3.41%0.28 0.34 34 13 ' 0.17 0.97%0.08 0.10 35 14 0.08 0.46%0.04 0.05 36 LACOL. 0.16 0.91%0.08 0.09 37 1 0.09 0.51%0.04 0.05 38 2 0.60 3.41%0.28 0.34 39 3 0.10 0.57%0.05 0.06 40 4 0.17 0.97%0.08 0.10 40 4 0.10 0.57%0.05 0.06 41 1-1 A 0.00 0.00%0.00 0.00 0.71 SUM TOTALS: 17.58 100.00% 8.35 10.05 2.25 STORM DRAINAGE REPORT FOR CEDAR CREST Phases 1 and 2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - EAST - 25 YR. FILE: 95123E25.STM RAINFALL FILE:25 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " O.,. LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DC lac) C (min) (in/h) (cfs) (cfs) (cfs) lin) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/ 1 CB 2-21A 0.0 0.58 13.30 0.00 0.00 0.00 36D 236.92 106 0.012 0.000 241.21 2.0 DNLN = 0 126.9 0.58 27.60 0.00 0.00 14.25 80.6 36D 235.60 0.012 1.25 241.21 2.0 2 CB 2-21 0.6 0.58 13.30 0.00 0.00 0.30 36D 237.70 78 0.012 0.000 241.29 2.0 DNLN = 1 126.9 0.58 26.96 0.00 0.00 14.25 72.3 36D 236.92 0.010 1.25 241.29 2.0 3 CB 1-8 0.0 0.58 13.30 0.00 0.00 0.00 36D 238.69 50 0.012 0.000 241.37 2.1 DNLN = 2 126.3 0.58 26.55 0.00 0.00 13.95 101.7 36D 237.70 0.020 1.25 241.37 1.9 4 CB 1-10 0.0 0.58 13.30 0.00 0.00 0.00 36D 239.78 210 0.012 -0.001 241.27 3.9 DNLN = 3 125.7 0.58 25.37 0.00 0.00 13.69 52.1 36D 238.69 0.005 1.25 241.45 2.0 5 CB 1-11 0.0 0.58 13.30 0.00 0.00 0.00 18D 240.47 39 0.012 -0.004 241.41 5.1 DNLN = 4 111.5 0.58 22.25 0.00 0.00 5.93 7.9 18D 240.28 0.005 1.25 241.57 3.6 6 CB 1-12 0.0 0.58 13.30 0.00 0.00 0.00 18D 242.61 210 0.012 0.005 243.51 5.0 DNLN = 5 110.8 0.58 21.56 0.00 0.00 5.60 8.0 18D 241.56 0.005 1.25 242.46 5.0 7 CB 1-12A 0.0 0.58 13.30 0.00 0.00 0.00 18D 242.80 38 0.012 -0.001 243.95 3.6 DNLN = 6 110.2 0.58 21.37 0.00 0.00 5.31 8.0 18D 242.61 0.005 1.25 244.01 3.1 8 CB 1-13A 0.0 0.58 13.30 0.00 0.00 0.00 15D 244.88 238 0.012 0.006 245.66 4.7 DNLN = 7 8.0 0.58 20.38 0.00 0.00 3.83 6.1 15D 243.05 0.008 1.25 244.21 3.2 9 CB 1-13 0.0 0.58 13.30 0.00 0.00 0.00 12D 245.32 38 0.012 -0.001 246.05 2.7, DNLN = 8 3.6 0.58 15.78 0.00 0.00 1.71 2.7 12D 245.13 0.005 1.25 246.10 2.2, 10 CB 3-53 0.1 0.58 13.30 0.00 0.00 0.05 12D 246.83 86 0.012 0.011 247.16 2.6, DNLN = 9 1.3 0.58 14.97 0.00 0.00 0.61 5.1 12D 245.32 0.018 1.25 246.20 0.8 11 CB 3-55 0.1 0.58 13.30 0.00 0.00 0.02 12D 247.36 53 0.012 0.007 247.68 2.6: DNLN = 10 1.2 0.58 14.54 0.001 0.00 0.56 3.9 12D 246.83 0.010 1.25 247.30 1.5, 12 CB 1-47 0.8 0.58 13.30 0.00 0.00 0.39 12D 245.53 41 0.012 -0.001 246.17 2.0f DNLN = 9 2.3 0.58 14.91 0.00 0.00 1.10 2.8 12D 245.32 0.005 1.25 246.20 1.5( 13 CB 1-48 0.2 0.58 13.30 0.00 0.00 0.12 12D 246.62 92 0.012 0.008 246.98 2.8: DNLN = 12 1.5 0.58 14.14 0.00 0.00 0.71 4.2 12D 245.53 0.012 1.25 246.25 1.1. 14 CB 1-50 1.2 0.58 13.30 0.00 0.00 0.59 12D 248.68 104 0.012 0.019 249.14 2.6E DNLN = 13 1.2 0.58 13.30 0.00 0.00 0.59 5.4 12D 246.62 0.020 1.25 247.13 1.4 15 CB 2-1 0.7 0.58 13.30 0.00 0.00 0.32 12D 245.31 36 0.012 -0.002 246.02 3.5- DNLN = 8 4.4 0.58 20.19 0.00 0.00 2.12 2.7 12D 245.13 0.005 1.25 246.10 2.7 16 CB 2-3 1.0 0.58 13.30 0.00 0.00 0.50 12D 247.95 147 0.012 0.015 248.52 3.9C DNLN = 15 3.8 0.58 19.40 0.00 0.00 1.80 5.2 12D 245.31 0.018 1.25 246.26 2.3. 17 CB 2-5 0.9 0.58 13.30 0.00 0.00 0.44 12D 252.35 200 0.012 0.020 252.83 3.4e. DNLN = 16 2.7 0.58 18.13 0.00 0.00 1.30 5.7 12D 247.95 0.022 1.25 248.81 1.80 18 CB 2-7 0.8 0.58 13.30 0.00 0.00 0.39 12D 256.64 200 0.012 0.020 257.03 3.0o DNLN = 17 1.8 0.58 16.63 0.00 0.00 0.86 5.7 12D 252.35 0.021 1.25 253.07 1.4s 19 CB 2-9 0.8 0.58 13.30 0.00 0.00 0.37 12D 261.15 200 0.012 0.021 261.44 2.48 DNLN = 18 1.0 0.58 14.72 0.00 0.00 0.47 5.8 12D 256.64 0.023 1.25 257.21 1.02 20 CB 2-11 0.2 0.58 13.30 0.00 0.00 0.10 12D 262.80 82 0.012 0.017 262.98 1.59 DNLN = 19 0.2 0.58 13.30 0.00 0.00 0.10 5.5 12D 261.15 0.020 1.25 261.56 0.3s 21 CB 1-51 0.6 0.58 13.30 0.00 0.00 0.29 12D 243.41 45 0.012 0.000 244.01 0.59 DNLN = 6 0.6 0.58 13.30 0.00 0.00 0.29 3.7 12D 242.99 0.009 1.25 244.01 0.37 22 CB 2-12 74.0 0.58 13.30 0.00 0.00 0.35 12D 243.38 40 0.012 0.000 244.20 2.16 DNLN = 7 102.1 0.58 17.15 0.00 0.00 1.48 2.7 12D 243.18 0.005 1.25 244.21 1.88 23 CB 2-14 1.0 0.58 13.30 0.00 0.00 0.49 12D 245.86 156 0.012 0.013 246.31 3.29 DNLN = 22 28.1 0.58 16.07 0.00 0.00 1.13 4.9 12D 243.38 0.016 1.25 244.29 1.51 24 CB 2-16 0.4 0.58 13.30 0.00 0.00 0.18 12D 249.84 190 0.012 0.019 250.18 2.73 DNLN = 23 27.1 0.58 14.44 0.00 0.00 0.64 5.6 12D 245.86 0.021 1.25 246.52 1.16 25 CB 2-18 26.0 0.58 13.30 0.00 0.00 0.12 12D 250.57 38 0.012 0.014 250.86 2.4E DNLN = 24 26.7 0.58 14.10 0.00 0.00 0.46 5.3 12D 249.84 0.019 1.25 250.32 1.22 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 & 2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - EAST - 25 YR. FILE: 95123E25.STM RAINFALL FILE:25 YEAR DESIGN STORM I = 0.000/ ( Tc f 0.000) " 0.0` INE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINEA TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOv ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 26 CB 2-19 0.7 0.58 13.30 0.00 0.00 0.34 12D 252.14 81 0.012 0.019 252.49 2.2` DNLN = 25 0.7 0.58 13.30 0.00 0.00 0.34 5.4 12D 250.57 0.019 1.25 250.98 1.14 27 CB 2-23 0.7 0.58 13.30 0.00 0.00 0.35 18D 240.95 36 0.012 0.012 242.01 5.8i DNLN = 4 14.2 0.58 25.25 0.00 0.00 7.76 15.5 18D 240.28 0.019 1.25 241.57 4.81 28 CB 2-25 0.8 0.58 13.30 0.00 0.00 0.37 18D 244.06 149 0.012 0.016 245.10 5.6E DNLN = 27 13.5 0.58 24.75 0.00 0.00 7.41 16.4 18D 240.95 0.021 1.25 242.66 4.1+ 29 CB 2-27 0.9 0.58 13.30 0.00 0.00 0.45 18D 247.69 150 0.012 0.020 248.70 5.55 DNLN = 28 12.7 0.58 24.22 0.00 0.00 7.04 17.7 18D 244.06 0.024 1.25 245.72 3.9E 30 CB 2-29 0.3 0.58 13.30 0.00 0.00 0.18 18D 251.33 152 0.012 0.020 252.31 5.3E DNLN = 29 11.8 0.58 23.67 0.00 0.00 6.59 17.6 18D 247.69 0.024 1.25 249.30 3.73 31 CB 2-30 1.2 0.58 13.30 0.00 0.00 0.58 18D 252.54 54 0.012 0.012 253.51 5.33 DNLN = 30 11.5 0.58 23.47 0.00 0.00 6.41 17.0 18D 251.33 0.022 1.25 252.87 3.63 32 CB 2-32 1.7 0.58 13.30 0.00 0.00 0.79 18D 257.39 203 0.012 0.021 258.31 5.11, DNLN = 31 10.3 0.58 22.66 0.00 0.00, 5.83 17.6 18D 252.54 0.024 1.25 254.06 3.31 33 CB 2-34 1.2 0.58 13.30 0.00 0.00 0.57 18D 262.24 200 0.012 0.021 263.10 4.83 DNLN = 32 8.6 0.58 21.80 0.00 0.00 5.04 17.7 18D 257.39 0.024 1.25 258.82 2.96 34 CB 2-36 0.8 0.58 13.30 0.00 0.00 0.39 18D 267.58 200 0.012 0.024 268.39 4.61 DNLN = 33 7.4 0.58 20.89 0.00 0.00 4.47 18.6 18D 262.24 0.027 1.25 263.55 2.73 35 CB 2-38 0.4 0.58 13.30 0.00 0.00 0.20 18D 271.48 103 0.012 0.034 272.25 4.49 DNLN = 34 6.6 0.58 20.41 0.00 0.00 4.08 22.1 18D 267.58 0.038 1.25 268.80 2.65 36 CB 2-39 1.0 0.58 13.30 0.00 0.00 0.46 18D 275.26 98 0.012 0.034 276.01 4.3E DNLN = 35 6.2 0.58 19.95 0.00 0.00 3.88 22.3 18D 271.48 0.039 1.25 272.64 2.65 37 CB 2-40 0.2 0.58 13.30 0.00 0.00 0.11 18D 275.90 56 0.012 0.004 276.61 4.19 DNLN = 36 5.2 0.58 19.66 0.00 0.00 3.42 12.2 18D 275.26 0.011 1.25 276.38 2.41 38 CB 2-41 0.3 0.58 13.30 0.00 0.00 0.15 18D 279.43 80 0.012 0.040 280.12 4.14 DNLN = 37 5.0 0.58 19.26 0.00 0.00 3.31 23.9 18D 275.90 0.044 1.25 276.95 2.52 39 CB 2-42 0.4 0.58 13.30 0.00 0.00 0.17 18D 286.30 106 0.012 0.062 286.98 4.07 DNLN = 38 4.7 0.58 18.72 0.00 0.00 3.16 29.0 18D 279.43 0.065 1.25 280.46 2.45 40 CB 2-45 0.4 0.58 13.30 0.00 0.00 0.19 18D 288.39 101 0.012 0.017 289.05 3.99 DNLN = 39 4.3 0.58 18.19 0.00 0.00 2.99 16.4 18D 286.30 0.021 1.25 287.30 2.39 41 CB 2-46 1.6 0.58 13.30 0.00 0.00 0.00 15D 291.46 146 0.012 0.019 292.13 4.18 DNLN = 40 3.9 0.58 17.59 0.00 0.00 2.80 9.7 15D 288.64 0.019 1.25 289.36 3.83 42 CB 2-47 0.0 0.58 13.30 0.00 0.00 0.34 15D 292.06 120 0.012 0.002 292.73 4.18 DNLN = 41 2.4 0.58 17.00 0.00 0.00 2.80 4.9 15D 291.46 0.005 1.25 292.47 2.64 43 CB 2-48 2.4 0.58 13.30 0.00 0.00 0.00 15D 292.60 108 0.012 0.001 293.23 3.99 DNLN = 42 2.4 0.58 16.43 0.00 0.00 2.46 4.9 15D 292.06 0.005 1.25 293.07 2.32 44 CB 2-49 0.0 0.58 13.30 0.00 0.00 0.95 15D 293.52 183 0.012 0.003 294.15 3.99 DNLN = 43 0.0 0.00 15.49 0.00 0.00 2.46 5.0 15D 292.60 0.005 1.25 293.54 2.49 45 CB 2-50 0.0 0.58 13.30 0.00 0.00 0.93 12D 296.23 147 0.012 0.016 296.75 3.65 DNLN = 44 0.0 0.00 14.71 0.00 0.00 1.51 5.0 12D 293.77 0.017 1.25 294.46 2.63 46 CB 2-51 0.0 0.58 13.30 0.00 0.00 0.58 12D 298.47 149 0.012 0.013 298.93 2.64 DNLN = 45 0.0 0.00 13.30 0.00 0.00 0.58 4.7 12D 296.23 0.015 1.25 297.01 0.88 47 CB 1-53 0.7 0.58 13.30 0.00 0.00 0.33 12D 241.22 50 0.012 0.000 241.92 0.57 DNLN = 5 0.7 0.58 13.30 0.00 0.00 0.33 2.7 12D 240.97 0.005 1.25 . 241.91 0.43 48 CB 1-55 0.5 0.58 13.30 0.00 0.00 0.26 15D 239.34 70 0.012 0.000 241.45 0.21 DNLN = 3 0.5 0.58 13.30 0.00 0.00 0.26 4.9 15D 238.99 0.005 1.25 241.45 0.21 49 CB 3-56 1.1 0.58 13.30 0.00 0.00 0.54 12D 248.91 155 0.012 0.010 249.35 2.59 DNLN = 11 1.1 0.58 13.30 0.00 0.00 0.54 3.9 12D 247.36 0.010 1.25 247.81 1.58 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 &2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - EAST - 100 YR. FILE: 95123E10.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0 LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/D( ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/ 1 CB 2-21A 0.0 0.58 13.30 0.00 0.00 0.00 36D 236.92 106 0.012 0.000 241.60 2.3 DNLN = 0 126.9 0.58 27.33 0.00 0.00 16.54 80.6 36D 235.60 0.012 1.25 241.60 2.3 2 CB 2-21 0.6 0.58 13.30 0.00 0.00 0.37 36D 237.70 78 0.012 0.000 241.71 2.3 DNLN = 1 126.9 0.58 26.78 0.00 0.00 16.54 72.3 36D 236.92 0.010 1.25 241.71 2.3 3 CB 1-8 0.0 0.58 13.30 0.00 0.00 0.00 36D 238.69 50 0.012 0.000 241.81 2.2 DNLN = 2 126.3 0.58 26.41 0.00 0.00 16.17 101.7 36D 237.70 0.020 1.25 241.81 2.2 4 CB 1-10 0.0 0.58 13.30 0.00 0.00 0.00 36D 239.78 210 0.012 0.000 241.86 3.0 DNLN = 3 125.7 0.58 25.09 0.00 0.00 15.86 52.1 36D 238.69 0.005 1.25 241.91 2.2 5 CB 1-11 0.0 0.58 13.30 0.00 0.00 0.00 18D 240.47 39 0.012 0.000 242.04 4.0 DNLN = 4 111.5 0.58 21.69 0.00 0.00 7.14 7.9 18D 240.28 0.005 1.25 242.04 4.0 6 CB 1-12 0.0 0.58 13.30 0.00 0.00 0.00 18D 242.61 210 0.012 0.005 243.60 5.4 DNLN = 5 110.8 0.58 21.05 0.00 0.00 6.74 8.0 18D 241.56 0.005 1.25 242.55 5.4 7 CB 1-12A 0.0 0.58 13.30 0.00 0.00 0.00 18D 242.80 38 0.012 -0.001 244.16 3.E DNLN = 6 110.2 0.58 20.88 0.00 0.00 6.39 8.0 18D 242.61 0.005 1.25 244.18 3.1 8 CB 1-13A 0.0 0.58 13.30 0.00 0.00 0.00 15D 244.88 238 0.012 0.005 245.74 5.1 DNLN = 7 8.0 0.58 19.98 0.00 0.00 4.61 6.1 15D 243.05 0.008 1.25 244.44 3.7 9 CB 1-13 0.0 0.58 13.30 0.00 0.00 0.00 12D 245.32 38 0.012 0.000 246.24 2.7 DNLN = 8 3.6 0.58 15.63 0.00 0.00 2.06 2.7 12D 245.13 0.005 1.25 246.25 2.6 10 CB 3-53 0.1 0.58 13.30 0.00 0.00 0.06 12D 246.83 86 0.012 0.009 247.19 2.8 DNLN = 9 1.3 0.58 14.88 0.00 0.00 0.74 5.1 12D 245.32 0.018 1.25 246.39 0.9 11 CB 3-55 0.1 0.58 13.30 0.00 0.00 0.03 12D 247.36 53 0.012 0.007 247.71 2.7 DNLN = 10 1.2 0.58 14.48 0.00 0.00 0.68 3.9 12D 246.83 0.010 1.25 247.35 1.6 12 CB 1-47 0.8 0.58 13.30 0.00 0.00 0.47 12D 245.53 41 0.012 0.000 246.38 1.8 DNLN = 9 2.3 0.58 14.84 0.00 0.00 1.32 2.8 12D 245.32 0.005 1.25 246.39 1.6 13 CB 1-48 0.2 0.58 13.30 0.00 0.00 0.14 12D 246.62 92 0.012 0.006 247.01 2.9' DNLN = 12 1.5 0.58 14.09 0.00 0.00 0.85 4.2 12D 245.53 0.012 1.25 246.44 1.1 14 CB 1-50 1.2 0.58 13.30 0.00 0.00 0.71 12D 248.68 104 0.012 0.019 249.19 2.8. DNLN = 13 1.2 0.58 13.30 0.00 0.00 0.71 5.4 12D 246.62 0.020 1.25 247.18 1.5' 15 CB 2-1 0.7 0.58 13.30 0.00 0.00 0.39 12D 245.31 36 0.012 0.000 246.24 3.3' DNLN = 8 4.4 0.58 19.80 0.00 0.00 2.55 2.7 12D 245.13 0.005 1.25 246.25 3.2' 16 CB 2-3 1.0 0.58 13.30 0.00 0.00 0.60 12D 247.95 147 0.012 0.014 248.57 4.2( DNLN = 15 3.8 0.58 19.10 0.00 0.00 2.16 5.2 12D 245.31 0.018 1.25 246.46 2.7 17 CB 2-5 0.9 0.58 13.30 0.00 0.00 0.53 12D 252.35 200 0.012 0.020 252.88 3.6' DNLN = 16 2.7 0.58 17.93 0.00 0.00 1.56 5.7 12D 247.95 0.022 1.25 248.92 2.0. 18 CB 2-7 0.8 0.58 13.30 0.00 0.00 0.48 12D 256.64 200 0.012 0.020 257.07 3.1' DNLN = 17 1.8 0.58 16.52 0.00 0.00 1.03 5.7 12D 252.35 0.021 1.25 253.14 1.5, 19 CB 2-9 0.8 0.58 13.30 0.00 0.00 0.44 12D 261.15 200 0.012 0.021 261.46 2.6( DNLN = 18 1.0 0.58 14.69 0.00 0.00 0.55 5.8 12D 256.64 0.023 1.25 257.27 1.0t 20 CB 2-11 0.2 0.58 13.30 0.00, 0.00 0.11 12D 262.80 82 0.012 0.017 262.99 1.6, DNLN = 19 0.2 0.58 13.30 0.00 0.00 0.11 5.5 12D 261.15 0.020 1.25 261.60 0.3, 21 CB 1-51 0.6 0.58 13.30 0.00 0.00 0.35 12D 243.41 45 0.012 0.000 244.18 0.5`_ DNLN = 6 0.6 0.58 13.30 0.00 0.00 0.35 3.7 12D 242.99 0.009 1.25 244.18 0.4` 22 CB 2-12 74.0 0.58 13.30 0.00 0.00 0.42 12D 243.38 40 0.012 0.000 244.44 2.2 DNLN = 7 102.1 0.58 16.90 0.00 0.00 1.78 2.7 12D 243.18 0.005 1.25 244.44 2.2; 23 CB 2-14 1.0 0.58 13.30 0.00 0.00 0.59 12D 245.86 156 0.012 0.012 246.35 3.51 DNLN = 22 28.1 0.58 15.91 0.00 0.00 1.36 4.9 12D 243.38 0.016 1.25 244.54 1.7, 24 CB 2-16 0.4 0.58 13.30 0.00 0.00 0.21 12D 249.84 190 0.012 0.019 250.21 2.8 DNLN = 23 27.1 0.58 14.38 0.00 0.00 0.77 5.6 12D 245.86 0.021 1.25 246.59 1.2 25 CB 2-18 26.0 0.58 13.30 0.00 0.00 0.15 12D 250.57 38 0.012 0.013 250.89 2.6, DNLN = 24 26.7 0.58 14.06 0.00 0.00 0.56 5.3 12D 249.84 0.019 1.25 250.37 1.31 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 & 2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - EAST - 100 YR. FILE: 95123E10.STM LINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " O.6 LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/D09. ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) )ft/ft) (ft/ft) (ft) (ft/ 26 CE 2-19 0.7 0.58 13.30 0.00 0.00 0.41 12D 252.14 81 0.012 0.019 252.52 2.32. DNLN = 25 0.7 0.58 13.30 0.00 0.00 0.41 5.4 12D 250.57 0.019 1.25 251.02 1.2( 27 CE 2-23 0.7 0.58 13.30 0.00 0.00 0.42 18D 240.95 36 0.012 0.001 242.08 6.1, DNLN = 4 14.2 0.58 24.98 0.00 0.00 8.72 15.5 18D 240.28 0.019 1.25 242.04 4.93 28 CE 2-25 0.8 0.58 13.30 0.00 0.00 0.45 18D 244.06 149 0.012 0.016 245.16 5.9P DNLN = 27 13.5 0.58 24.51 0.00 0.00 8.30 16.4 18D 240.95 0.021 1.25 242.80 4.76 29 CB 2-27 0.9 0.58 13.30 0.00 0.00 0.54 18D 247.69 150 0.012 0.019 248.76 5.83 DNLN = 28 12.7 0.58 24.03 0.00 0.00 7.85 17.7 18D 244.06 0.024 1.25 245.85 4.44 30 CB 2-29 0.3 0.58 13.30 0.00 0.00 0.18 18D 251.33 152 0.012 0.019 252.36 5.64 DNLN = 29 11.8 0.58 23.51 0.00 0.00 7.31 17.6 18D 247.69 0.024 1.25 249.42 4.14 31 CB 2-30 1.2 0.58 13.30 0.00 0.00 0.69 18D 252.54 54 0.012 0.011 253.56 5.58 DNLN = 30 11.5 0.58 23.32 0.00 0.00 7.13 17.0 18D 251.33 0.022 1.25 252.98 4.03 32 CB 2-32 1.7 0.58 13.30 0.00 0.00 0.95 18D 257.39 203 0.012 0.021 258.36 5.34 DNLN = 31 10.3 0.58 22.57 0.00 0.00 6.44 17.6 18D 252.54 0.024 1.25 254.16 3.64 33 CB 2-34 1.2 0.58 13.30 0.00 0.00 0.68 18D 262.24 200 0.012 0.021 263.13 5.00 DNLN = 32 8.6 0.58 21.74 0.00 0.00 5.49 17.7 18D 257.39 0.024 1.25 258.91 3.11 34 CB 2-36 0.8 0.58 13.30 0.00 0.00 0.46 18D 267.58 200 0.012 0.024 268.42 4.7' DNLN = 33 7.4 0.58 20.86 0.00 0.00 4.81 18.6 18D 262.24 0.027 1.25 263.62 2.83 35 CB 2-38 0.4 0.58 13.30 0.00 0.00 0.24 18D 271.48 103 0.012 0.033 272.28 4.5, DNLN = 34 6.6 0.58 20.39 0.00 0.00 4.35 22.1 18D 267.58 0.038 1.25 268.85 2.72 36 CB 2-39 1.0 0.58 13.30 0.00 0.00 0.56 18D 275.26 98 0.012 0.034 276.03 4.4, DNLN = 35 6.2 0.58 19.94 0.00 0.00 4.11 22.3 18D 271.48 0.039 1.25 272.68 2.71 37 CB 2-40 0.2 0.58 13.30 0.00 0.00 0.13 18D 275.90 56 0.012 0.004 276.62 4.24 DNLN = 36 5.2 0.58 19.66 0.00 0.00 3.55 12.2 18D 275.26 0.011 1.25 276.42 2.42 38 CB 2-41 0.3 0.58 13.30 0.00 0.00 0.18 18D 279.43 80 0.012 0.040 280.14 4.19 DNLN = 37 5.0 0.58 19.26 0.00 0.00 3.42 23.9 18D 275.90 0.044 1.25 276.97 2.54 39 CB 2-42 0.4 0.58 13.30 0.00 0.00 0.21 18D 286.30 106 0.012 0.061 286.99 4.11 DNLN = 38 4.7 0.58 18.72 0.00 0.00 3.24 29.0 18D 279.43 0.065 1.25 280.48 2.4E 40 CB 2-45 0.4 0.58 13.30 0.00 0.00 0.23 18D 288.39 101 0.012 0.017 289.05 4.01 DNLN = 39 4.3 0.58 18.20 0.00 0.00 3.03 16.4 18D 286.30 0.021 1.25 287.31 2.38 41 CB 2-46 1.6 0.58 13.30 0.00 0.00 0.00 15D 291.46 146 0.012 0.019 292.13 4.18 DNLN = 40 3.9 0.58 17.59 0.00 0.00 2.80 9.7 15D 288.64 0.019 1.25 289.37 3.78 42 CB 2-47 0.0 0.58 13.30 0.00 0.00 0.34 15D 292.06 120 0.012 0.002 292.73 4.1E DNLN = 41 2.4 0.58 17.00 0.00 0.00 2.80 4.9 15D 291.46 0.005 1.25 292.47 2.64 43 CB 2-48 2.4 0.58 13.30 0.00 0.00 0.00 15D 292.60 108 0.012 0.001 293.23 3.99 DNLN = 42 2.4 0.58 16.43 0.00 0.00 2.46 4.9 15D 292.06 0.005 1.25 293.07 2.32 44 CB 2-49 0.0 0.58 13.30 0.00 0.00 0.95 15D 293.52 183 0.012 0.003 294.15 3.99 DNLN = 43 0.0 0.00 15.49 0.00 0.00 2.46 5.0 15D 292.60 0.005 1.25 293.54 2.49 45 CB 2-50 0.0 0.58 13.30 0.00 0.00 0.93 12D 296.23 147 0.012 0.016 296.75 3.65 DNLN = 44 0.0 0.00 14.71 0.00 0.00 1.51 5.0 12D 293.77 0.017 1.25 294.46 2.63 46 CB 2-51 0.0 0.58 13.30 0.00 0.00 0.58 12D 298.47 149 0.012 0.013 298.93 2.64 DNLN = 45 0.0 0.00 13.30 0.00 0.00 0.58 4.7 12D 296.23 0.015 1.25 297.01 0.8E 47 CB 1-53 0.7 0.58 13.30 0.00 0.00 0.40 12D 241.22 50 0.012 0.000 242.36 0.51 DNLN = 5 0.7 0.58 13.30 0.00 0.00 0.40 2.7 12D 240.97 0.005 1.25 242.35 0.51 48 CB 1-55 0.5 0.58 13.30 0.00 0.00 0.31 15D 239.34 70 0.012 0.000 241.92 0.25 DNLN = 3 0.5 0.58 13.30 0.00 0.00 0.31 4.9 15D 238.99 0.005 1.25 241.91 0.25 49 CB 3-56 1.1 0.58 13.30 0.00 0.00 0.65 12D 248.91 155 0.012 0.010 249.40 2.74 DNLN = 11 1.1 0.58 13.30 0.00 0.00 0.65 3.9 12D 247.36 0.010 1.25 247.86 1.6E HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 & 2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - WEST - 25 YR. FILE: 95123W25.STM RAINFALL FILE: 25 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0. l0 LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINEM TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOui ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/ 1 1 CB EX-24 0.0 0.58 13.30 0.00 0.00 0.00 36D 236.20 36 0.012 0.000 241.21 1.5 DNLN = 0 17.5 0.58 40.24 0.00 0.00 11.01 93.3 36D 235.60 0.017 1.25 241.21 1.5, 2 CB 1-1 0.0 0.58 13.30 0.00 0.00 0.20 36D 236.59 39 0.012 0.000 241.26 1.21 DNLN = 1 13.8 0.58 39.71 0.00 0.00 8.79 91.8 36D 235.96 0.016 1.25 241.26 1.21 3 CB 1-2 0.0 0.58 13.30 0.00 0.00 0.91 36D 237.31 72 0.012 0.000 241.29 1.1. DNLN = 2 13.8 0.58 38.64 0.00 0.00 7.88 72.3 36D 236.59 0.010 1.25 241.29 1.1 4 CB 1-3 0.1 0.58 13.30 0.00 0.00 0.05 36D 237.78 43 0.012 0.000 241.31 0.91 DNLN = 3 13.8 0.58 37.91 0.00 0.00 6.97 92.8 36D 237.07 0.017 1.25 241.31 0.91 5 CB 1-5 0.0 0.58 13.30 0.00 0.00 0.00 24D 238.84 37 0.012 0.000 241.33 0.91 DNLN = 4 6.5 0.58 26.00 0.00 0.00 3.11 17.6 24D 238.65 0.005 1.25 241.33 0.9 6 CB 1-26 0.3 0.58 13.30 0.00 0.00 0.14 24D 239.05 42 0.012 0.000 241.35 0.9 DNLN = 5 6.3 0.58 20.86 0.00 0.00 3.01 17.3 24D 238.84 0.005 1.25 241.35 0.9 7 CB 1-27 0.0 0.58 13.30 0.00 0.00 0.02 8D 239.84 26 0.012 0.000 241.37 0.0 , DNLN = 6 0.0 0.58 13.30 0.00 0.00 0.02 1.9 8D 239.32 0.020 1.25 241.37 0.0 , 8 CB 1-28 0.2 0.58 13.30 0.00 0.00 0.07 24D 239.31 51 0.012 0.000 241.37 0.9 DNLN = 6 6.0 0.58 18.22 0.00 0.00 2.85 17.5 24D 239.05 0.005 1.25 241.37 0.9 9 CB 1-29 0.8 0.58 13.30 0.00 0.00 0.39 12D 241.30 80 0.012 0.003 241.65 2.71 DNLN = 8 1.4 0.58 15.61 0.00 0.00 0.68 5.0 12D 239.97 0.017 1.25 241.38 0.8 10 CB 1-31 0.6 0.58 13.30 0.00 0.00 0.29 12D 244.45 200 0.012 0.015 244.77 2.1 DNLN = 9 0.6 0.58 13.30 0.00 0.00 0.29 4.8 12D 241.30 0.016 1.25 241.80 0.71 11 CB 1-33 0.5 0.58 13.30 0.00 0.00 0.23 18D 240.33 62 0.012 0.000 241.36 1.6 DNLN = 8 4.4 0.58 17.49 0.00 0.00 2.10 8.0 18D 240.02 0.005 1.25 241.38 1.2 , 12 CB 1-35 0.4 0.58 13.30 0.00 0.00 0.18 15D 241.98 136 0.012 0.008 242.53 3.6 DNLN = 11 3.9 0.58 16.81 0.00 0.00 1.87 6.6 15D 240.78 0.009 1.25 241.41 3.0 13 CB 1-42 0.5 0.58 13.30 0.00 0.00 0.25 12D 245.45 115 0.012 0.026 245.80 2.7 DNLN = 12 1.4 0.58 14.74 0.00 0.00 0.67 6.5 12D 242.23 0.028 1.25 242.78 1.5 14 CB 1-44 0.9 0.58 13.30 0.00 0.00 0.42 12D 249.50 150 0.012 0.026 249.89 2.4 DNLN = 13 0.9 0.58 13.30 0.00 0.00 0.42 6.3 12D 245.45 0.027 1.25 245.95 1.0 15 CB 1-36 0.5 0.58 13.30 0.00 0.00 0.25 12D 242.52 58 0.012 0.003 242.95 3.1 DNLN = 12 2.2 0.58 16.46 0.00 0.00 1.02 2.7 12D 242.23 0.005 1.25 242.78 2.3, 16 CB 1-38 1.0 0.58 13.30 0.00 0.00 0.48 12D 244.70 105 0.012 0.018 245.07 2.8 DNLN = 15 1.6 0.58 15.66 0.00 0.00 0.77 5.6 12D 242.52 0.021 1.25 243.14 1.4 17 CB 1-40 0.6 0.58 13.30 0.00 0.00 0.29 12D 248.03 200 0.012 0.016 248.35 2.1' DNLN = 16 0.6 0.58 13.30 0.00 0.00 0.29 5.0 12D 244.70 0.017 1.25 245.23 0.6: 18 CB 1-7 0.1 0.58 13.30 0.00 0.00 0.05 12D 239.25 94 0.012 0.000 241.33 0.0: DNLN = 4 0.1 0.58 13.30 0.00 0.00 0.05 2.7 12D 238.78 0.005 1.25 241.33 0.0: 19 CB 1-4 0.1 0.58 13.30 0.00 0.00 0.46 18D 240.96 174 0.012 0.002 241.70 4.31 DNLN = 4 7.0 0.58 18.55 0.00 0.00 3.76 13.1 18D 238.65 0.013 1.25 241.33 2.1 20 CB 1-14 0.9 0.58 13.30 0.00 0.00 0.43 15D 241.70 97 0.012 0.004 242.43 4.4' DNLN = 19 6.9 0.58 18.16 0.00 0.00 3.30 5.0 15D 241.21 0.005 1.25 242.06 3.7( 21 CB 1-16 1.1 0.58 13.30 0.00 0.00 0.52 15D 243.10 131 0.012 0.007 243.78 4.2: DNLN = 20 6.0 0.58 17.51 0.00 0.00 2.87 7.2 15D 241.70 0.011 1.25 242.81 2.4' 22 CB 1-18 0.6 0.58 13.30 0.00 0.00 0.27 12D 245.75 202 0.012 0.011 246.40 4.3 DNLN = 21 4.9 0.58 16.66 0.00 0.00 2.35 4.2 12D 243.35 0.012 1.25 244.12 3.6 23 CB 1-20 0.8 0.58 13.30 0.00 0.00 0.36 12D 245.91 32 0.012 -0.001 246.74 2.9 DNLN = 22 4.4 0.58 16.47 0.00 0.00 2.08 2.7 12D 245.75 0.005 1.25 246.77 2.6 24 CB 1-21 0.7 0.58 13.30 0.00 0.00 0.35 12D 246.07 32 0.012 -0.001 246.89 2.5 DNLN = 23 3.6 0.58 16.24 0.00 0.00 1.72 2.7 12D 245.91 0.005 1.25 246.91 2.1' 25 CB 1-22 1.4 0.58 13.30 0.00 0.00 0.66 12D 247.86 201 0.012 0.007 248.36 3.5. DNLN = 24 2.9 0.58 14.98 0.00 0.00 1.37 3.6 12D 246.07 0.009 1.25 247.01 1.7' HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 & 2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - WEST - 25 YR. FILE: 95123W25.STM RAINFALL FILE: 25 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.0 ENE* DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOH ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 26 CB 1-24 1.5 0.58 13.30 0.00 0.00 0.71 12D 250.76 200 0.012 0.013 251.27 2.82 DNLN = 25 1.5 0.58 13.30 0.00 0.00 0.71 4.6 12D 247.86 0.014 1.25 248.60 1.14 27 CB 1-6 0.2 0.58 13.30 0.00 0.00 0.10 12D 239.83 97 0.012 0.000 241.35 0.13 DNLN = 5 0.2 0.58 13.30 0.00 0.00 0.10 2.7 12D 239.34 0.005 1.25 241.35 0.13 28 CB EX.0.0 0.58 13.30 0.00 0.00 0.00 15D 238.87 117 0.012 0.000 241.26 1.81 DNLN = 1 3.7 0.58 24.68 0.00 0.00 2.22 16.0 15D 232.74 0.052 1.25 241.26 1.81 29 CB EX.0.0 0.58 13.30 0.00 0.00 0.00 15D 240.62 120 0.012 -0.001 241.22 3.84 DNLN = 28 3.7 0.58 23.97 0.00 0.00 2.22 8.4 15D 238.87 0.015 1.25 241.32 1.81 30 CB 7 0.6 0.58 13.30 0.00 0.00 0.26 12D 251.84 49 0.012 0.221 252.33 3.48 DNLN = 29 2.8 0.58 23.66 0.00 0.00 1.32 18.5 12D 240.62 0.229 1.25 241.50 1.80 31 CB 8 0.5 0.58 13.30 0.00 0.00 0.22 12D 251.97 26 0.012 -0.002 252.52 2.39 DNLN = 30 2.2 0.58 23.45 0.00 0.00 1.06 2.7 12D 251.84 0.005 1.25 252.56 1.75 32 CB 9 0.7 0.58 13.30 0.00 0.00 0.35 12D 278.85 301 0.012 0.088 279.24 2.98 DNLN = 31 1.7 0.58 21.22 0.00 0.00 0.84 11.5 12D 251.97 0.089 1.25 252.63 1.52 33 CB 11 0.6 0.58 13.30 0.00 0.00 0.29 12D 291.74 301 0.012 0.042 292.04 2.51 DNLN = 32 1.0 0.58 18.43 0.00 0.00 0.49 8.0 12D 278.85 0.043 1.25 279.41 1.08 34 CB 13 0.2 0.58 13.30 0.00 0.00 0.08 12D 302.79 197 0.012 0.055 302.98 1.93 DNLN = 33 0.4 0.58 15.88 0.00 0.00 0.20 9.1 12D 291.74 0.056 1.25 292.16 0.64 35 CB 14 0.1 0.58 13.30 0.00 0.00 0.04 12D 302.93 28 0.012 0.001 303.08 1.67 DNLN = 34 0.2 0.58 15.49 0.00 0.00 0.12 2.7 12D 302.79 0.005 1.25 303.05 0.73 36 CB LA COLINA 0.2 0.58 13.30 0.00 0.00 0.08 12D 307.21 145 0.012 0.029 307.37 1.50 DNLN = 35 0.2 0.58 13.30 0.00 0.00 0.08 6.6 12D 302.93 0.030 1.25 303.13 0.71 37 CB 1 0.1 0.58 13.30 0.00 0.00 0.47 12D 243.84 141 0.012 0.019 244.24 3.05 DNLN = 29 1.0 0.58 18.60 0.00 0.00 0.90 5.8 12D 240.62 0.023 1.25 241.50 1.23 38 CB 2 0.6 0.58 13.30 0.00 0.00 0.29 12D 244.60 76 0.012 0.006 244.88 2.41 DNLN = 37 0.9 0.58 17.83 0.00 0.00 0.43 3.9 12D 243.84 0.010 1.25 244.42 0.91 39 CB 3 0.1 0.58 13.30 0.00 0.00 0.05 12D 247.38 151 0.012 0.017 247.54 1.75 DNLN = 38 0.3 0.58 15.59 0.00 0.00 0.14 5.2 12D 244.60 0.018 1.25 244.99 0.49 40 CB 4 0.2 0.58 13.30 0.001 0.00 0.09 12D 260.89 155 0.012 0.087 261.06 1.55 DNLN = 39 0.2 0.58 13.30 0.001 0.00 0.09 11.4 12D 247.38 0.087 1.25 247.60 0.71 41 CB 1-lA 0.0 0.58 13.30 0.001 0.00 0.71 12D 240.21 31 0.012 0.001 241.30 0.90 DNLN = 2 0.0 0.00 13.30 0.001 0.00 0.71 8.9 12D 238.55 0.054 1.25 241.29 0.90 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 &2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - WEST - 100 YR. FILE: 95123W10.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0 0( LINE* DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE4 TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DC' N lac) C (min) (in/h) Icfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/ 1 CB EX-24 0.0 0.56 13.30 0.00 0.00 0.00 36D 236.20 36 0.012 0.000 241.60 1.; DNLN = 0 17.5 0.58 35.80 0.00 0.00 12.67 93.3 36D 235.60 0.017 1.25 241.60 1.% 2 CB 1-1 0.0 0.58 13.30 0.00 0.00 0.20 36D 236.59 39 0.012 0.000 241.66 1.4 DNLN = 1 13.8 0.58 35.34 0.00 0.00 10.11 91.8 36D 235.96 0.016 1.25 241.66 1.4 3 CB 1-2 0.0 0.58 13.30 0.00 0.00 0.91 36D 237.31 72 0.012 0.000 241.70 1.3 DNLN = 2 13.8 0.58 34.42 0.00 0.00 9.20 72.3 36D 236.59 0.010 1.25 241.70 1.3 4 CB 1-3 0.1 0.58 13.30 0.00 0.00 0.05 36D 237.78 43 0.012 0.000 241.73 1.1 DNLN = 3 13.8 0.58 33.81 0.00 0.00 8.29 92.8 36D 237.07 0.017 1.25 241.73 1.1 5 CB 1-5 0.0 0.58 13.30 0.00 0.00 0.00 24D 238.84 37 0.012 0.000 241.76 1.1 DNLN = 4 6.5 0.58 24.84 0.00 0.00 3.74 17.6 24D 238.65 0.005 1.25 241.76 1.1 6 CB 1-26 0.3 0.58 13.30 0.00 0.00 0.17 24D 239.05 42 0.012 0.000 241.79 1.1 DNI`N = 5 6.3 0.58 20.86 0.00 0.00 3.63 17.3 24D 238.84 0.005 1.25 241.79 1.1 7 CB 1-27 0.0 0.58 13.30 0.00 0.00 0.02 SD 239.84 26 0.012 0.000 241.82 0.0 DNLN = 6 0.0 0.58 13.30 0.00 0.00 0.02 1.9 8D 239.32 0.020 1.25 241.82 0.0 8 CB 1-28 0.2 0.58 13.30 0.00 0.00 0.09 24D 239.31 51 0.012 0.000 241.82 1.0 DNLN = 6 6.0 0.58 18.12 0.00 0.00 3.44 17.5 24D 239.05 0.005 1.25 241.82 1.0 9 CB 1-29 0.8 0.58 13.30 0.00 0.00 0.48 12D 241.30 80 0.012 -0.001 241.78 2.2 DNLN = 8 1.4 0.58 15.51 0.00 0.00 0.83 5.0 12D 239.97 0.017 1.25 241.84 1.0 10 CB 1-31 0.6 0.58 13.30 0.00 0.00 0.35 12D 244.45 200 0.012 0.015 244.80 2.2 DNLN = 9 0.6 0.58 13.30 0.00 0.00 0.35 4.8 12D 241.30 0.016 1.25 241.88 0.7 11 CB 1-33 0.5 0.58 13.30 0.00 0.00 0.27 18D 240.33 62 0.012 0.000 241.84 1.4! DNLN = 8 4.4 0.58 17.39 0.00 0.00 2.52 8.0 18D 240.02 0.005 1.25 241.84 1.4: 12 CB 1-35 0.4 0.58 13.30 0.00 0.00 0.21 15D 241.98 136 0.012 0.005 242.58 3.8. DNLN = 11 3.9 0.58 16.62 0.00 0.00 2.25 6.6 15D 240.78 0.009 1.25 241.88 1.9 13 CB 1-42 0.5 0.58 13.30 0.00 0.00 0.30 12D 245.45 115 0.012 0.026 245.83 2.91 DNLN = 12 1.4 0.58 14.65 0.00 0.00 0.81 6.5 12D 242.23 0.028 1.25 242.87 1.5, 14 CB 1-44 0.9 0.58 13.30 0.00 0.00 0.51 12D 249.50 150 0.012 0.026 249.93 2.5) DNLN = 13 0.9 0.58 13.30 0.00 0.00 0.51 6.3 12D 245.45 0.027 1.25 246.00 1.1 15 CB 1-36 0.5 0.58 13.30 0.00 0.00 0.30 12D 242.52 58 0.012 0.002 242.99 3.3 DNLN = 12 2.2 0.58 16.28 0.00 0.00 1.23 2.7 12D 242.23 0.005 1.25 242.87 2.3 16 CB 1-38 1.0 0.58 13.30 0.00 0.00 0.58 12D 244.70 105 0.012 0.018 245.11 3.0 DNLN = 15 1.6 0.58 15.53 0.00 0.00 0.93 5.6 12D 242.52 0.021 1.25 243.21 1.6 17 CB 1-40 0.6 0.58 13.30 0.00 0.00 0.35 12D 248.03 200 0.012 0.015 248.38 2.2 DNLN = 16 0.6 0.58 13.30 0.00 0.00 0.35 5.0 12D 244.70 0.017 1.25 245.29 0.7 18 CB 1-7 0.1 0.58 13.30 0.00 0.00 0.06 12D 239.25 94 0.012 0.000 241.76 0.0 DNLN = 4 0.1 0.58 13.30 0.00 0.00 0.06 2.7 12D 238.78 0.005 1.25 241.76. 0.0 ' 19 CB 1-4 0.1 0.58 13.30 0.00 0.00 0.47 18D 240.96 174 0.012 0.000 241.76 4.6 DNLN = 4 7.0 0.58 18.13 0.00 0.00 4.44 13.1 18D 238.65 0.013 1.25 241.76 2.5 20 CB 1-14 0.9 0.58 13.30 0.00 0.00 0.52 15D 241.70 97 0.012 0.003 242.50 4.8 DNLN = 19 6.9 0.58 17.76 0.00 0.00 3.97 5.0 15D 241.21 0.005 1.25 242.18 3.9 21 CB 1-16 1.1 0.58 13.30 0.00 0.00 0.62 15D 243.10 131 0.012 0.007 243.84 4.5 DNLN = 20 6.0 0.58 17.17 0.00 0.00 3.45 7.2 15D 241.70 0.011 1.25 242.95 2.8 22 CB 1-18 0.6 0.58 13.30 0.00 0.00 0.33 12D 245.75 202 0.012 0.011 246.46 4.7. DNLN = 21 4.9 0.58 16.38 0.00 0.00 2.83 4.2 12D 243.35 0.012 1.25 244.24 3.8. 23 CB 1-20 0.8 0.58 13.30 0.00 0.00 0.43 12D 245.91 32 0.012 0.000 246.89 3.1' DNLN = 22 4.4 0.58 16.21 0.00 0.00 2.50 2.7 12D 245.75 0.005 1.25 246.90 3.1, 24 CB 1-21 0.7 0.58 13.30 0.00 0.00 0.42 12D 246.07 32 0.012 0.000 247.09 2.6 DNLN = 23 3.6 0.58 16.01 0.00 0.00 2.07 2.7 12D 245.91 0.005 1.25 247.09 2.6 25 CB 1-22 1.4 0.58 13.30 0.00 0.00 0.79 12D 247.86 201 0.012 0.006 248.40 3.7' DNLN = 24 2.9 0.58 14.87 0.00 0.00 1.65 3.6 12D 246.07 0.009 1.25 247.23 2.1( HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 &2 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 1 - WEST - 100 YR. FILE: 95123W10.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) ^ 0.0 NE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL LOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOW ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 26 CB 1-24 1.5 0.58 13.30 0.00 0.00 0.86 12D 250.76 200 0.012 0.013 251.33 3.00 DNLN = 25 1.5 0.58 13.30 0.00 0.00 0.86 4.6 12D 247.86 0.014 1.25 248.68 1.25 27 CB 1-6 0.2 0.58 13.30 0.00 0.00 0.11 12D 239.83 97 0.012 0.000 241.79 0.14 DNLN = 5 0.2 0.58 13.30 0.00 0.00 0.11 2.7 12D 239.34 0.005 1.25 241.79 0.14 28 CB EX.0.0 0.58 13.30 0.00 0.00 0.00 15D 238.87 117 0.012 0.000 241.66 2.09 DNLN = 1 3.7 0.58 24.41 0.00 0.00 2.56 16.0 15D 232.74 0.052 1.25 241.66 2.09 29 CB EX.0.0 0.58 13.30 0.00 0.00 0.00 15D 240.62 120 0.012 0.000 241.74 2.21 DNLN = 28 3.7 0.58 23.48 0.00 0.00 2.56 8.4 15D 238.87 0.015 1.25 241.75 2.09 30 CB 7 0.6 0.58 13.30 0.00 0.00 0.31 12D 251.84 49 0.012 0.215 252.37 3.70 DNLN = 29 2.8 0.58 23.19 0.00 0.00 1.57 18.5 12D 240.62 0.229 1.25 241.83 2.00 31 CB 8 0.5 0.58 13.30 0.00 0.00 0.26 12D 251.97 26 0.012 -0.001 252.60 2.42 DNLN = 30 2.2 0.58 22.99 0.00 0.00 1.26 2.7 12D 251.84 0.005 1.25 252.64 1.88 32 CB 9 0.7 0.58 13.30 0.00 0.00 0.42 12D 278.85 301 0.012 0.088 279.27 3.15 DNLN = 31 1.7 0.58 20.88 0.00 0.00 1.00 11.5 12D 251.97 0.089 1.25 252.71 1.60 33 CB 11 0.6 0.58 13.30 0.00 0.00 0.34 12D 291.74 301 0.012 0.042 292.06 2.64 DNLN = 32 1.0 0.58 18.23 0.00 0.00 0.58 8.0 12D 278.85 0.043 1.25 279.47 1.14 34 CB 13 0.2 0.58 13.30 0.00 0.00 0.10 12D 302.79 197 0.012 0.055 303.00 2.03 DNLN = 33 0.4 0.58 15.81 0.00 0.00 0.24 9.1 12D 291.74 0.056 1.25 292.20 0.68 35 CB 14 0.1 0.58 13.30 0.00 0.00 0.05 12D 302.93 28 0.012 0.000 303.09 1.75 DNLN = 34 0.2 0.58 15.44 0.00 0.00 0.14 2.7 12D 302.79 0.005 1.25 303.08 0.75 36 CB LA COLINA 0.2 0.58 13.30 0.00 0.00 0.09 12D 307.21 145 0.012 0.029 307.38 1.55 DNLN = 35 0.2 0.58 13.30 0.00 0.00 0.09 6.6 12D 302.93 0.030 1.25 303.15 0.71 37 CB 1 0.1 0.58 13.30 0.00 0.00 0.48 12D 243.84 141 0.012 0.017 244.26 3.14 DNLN = 29 1.0 0.58 18.30 0.00 0.00 0.99 5.8 12D 240.62 0.023 1.25 241.83 1.26 38 CB 2 0.6 0.58 13.30 0.00 0.00 0.34 12D 244.60 76 0.012 0.006 244.90 2.54 DNLN = 37 0.9 0.58 17.58 0.00 0.00 0.51 3.9 12D 243.84 0.010 1.25 244.45 1.01 39 CB 3 0.1 0.58 13.30 0.00 0.00 0.06 12D 247.38 151 0.012 0.017 247.55 1.84 DNLN = 38 0.3 0.58 15.46 0.00 0.00 0.17 5.2 12D 244.60 0.018 1.25 245.03 0.53 40 CB 4 0.2 0.58 13.30 0.00 0.00 0.11 12D 260.89 155 0.012 0.087 261.08 1.64 DNLN = 39 0.2 0.58 13.30 0.00 0.00 0.11 11.4 12D 247.38 0.087 1.25 247.62 0.76 41 CB 1-lA 0.0 0.58 13.30 0.00 0.00 0.71 12D 240.21 31 0.012 0.001 241.72 0.90 DNLN = 2 0.0 0.00 13.30 0.00 0.00 0.71 8.9 12D 238.55 0.054 1.25 241.70 0.90 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 &2 02/10/99 STORM SEWER SUMMARY REPORT CEDAR CREST - EMERGENCY OVERFLOW PIPE FILE: 951230V4.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0. 70 LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DC, s; lac) C (min) lin/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/ 1 CB 1 0.0 0.58 0.00 0.00 0.00 0.00 30D 220.16 157 0.012 0.004 222.45 10.1 DNLN = 0 0.0 0.00 3.64 0.00 0.00 47.57 26.5 30D 219.60 0.004 1.25 221.89 10.1 2 CB 2 0.0 0.58 0.00 0.00 0.00 0.00 30D 221.04 186 0.012 0.000 224.43 9.6 DNLN = 1 0.0 0.00 3.32 0.00 0.00 47.57 30.6 30D 220.16 0.005 1.25 224.43 9.6 3 CB 3 0.0 0.58 0.00 0.00 0.00 0.00 30D 223.57 202 0.012 0.000 226.25 9.6, DNLN = 2 0.0 0.00 2.97 0.00 0.00 47.57 49.7 30D 221.04 0.013 1.25 226.25 9.6; 4 CB 4 0.0 0.58 0.00 0.00 0.00 0.00 30D 229.39 85 0.012 0.042 231.68 10.1. DNLN = 3 0.0 0.00 2.83 0.00 0.00 47.57 99.6 30D 225.12 0.050 1.25 228.08 9.6 5 CB 5 0.0 0.58 0.00 0.00 0.00 0.00 30D 235.10 368 0.012 0.008 236.60 6.5 DNLN = 4 0.0 0.00 1.67 0.00 0.00 20.09 52.6 30D 229.94 0.014 1.25 233.66 4.0; 6 CB 6 0.0 0.58 0.00 0.00 0.00 0.64 24D 240.81 520 0.012 0.009 242.33 7.1' DNLN = 5 0.0 0.00 0.34 0.00 0.00 18.35 25.7 24D 235.10 0.011 1.25 237.43 5.8 7 CB 7 0.0 0.58 0.00 0.00 0.00 0.00 24D 241.93 100 0.012 0.001 243.42 7.0 DNLN = 6 0.0 0.00 0.08 0.00 0.00 17.71 25.9 24D 240.81 0.011 1.25 243.33 5.61 8 POND C OVERFLOW 0.0 0.58 0.00 0.00 0.00 17.71 24D 242.47 27 0.012 0.023 245.01 5.7 DNLN = 7 0.0 0.00 0.00 0.00 0.00 17.71 34.7 24D 241.93 0.020 1.25 244.39 5.6i 9 POND A OVERFLOW 0.0 0.58 0.00 0.00 0.00 27.48 24D 235.87 294 0.012 0.019 239.31 9.1: DNLN = 4 0.0 0.00 0.00 0.00 0.00 27.48 34.8 24D 229.94 0.020 1.25 233.66 8.7 10 POND B OVERFLOW 0.0 0.58 0.00 0.00 0.00 1.74 24D 238.99 168 0.012 0.006 239.66 3.5, DNLN = 5 0.0 0.00 0.00 0.00 0.00 1.74 17.3 24D 238.15 0.005 1.25 238.58 3.5, HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 1 & 2 CEDAR CREST PHASES III & IV Renton, Washington Storm Drainage Report Prepared by: rkLDScottR. Borgeson afw, ti +f Reviewed by: 4 y o ' . Donald J. Hill, P.E. A, a A 25390 ii 1' , lS1_a31ONAL EXPIRES G/8/f 9 CMilft TRIAD ASSOCIATES February 1 1 , 1 999 TRIAD JOB # 95 - 123 Page King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART 1 PROJECT OWNER AND PART 2 PROJECT LOCATION PROJECT ENGINEER AND DESCRIPTION a Pianta Ltd . Ptnrshp . , In Project Owner 1 8 0 0 0 Andover Prk . W. Ste 2 e 0Project Name Cedar Crest Address DBA/Segale Business Prk . LocationTukwile , WA 9-818-8--_-4798 23NTownshipPhone ( 206 ) 575-3200 5E Donald J . Hill RangeProjectEngineer Section 1 6 Company Triad Associates 12711814115thAve . NE Project Size r AC Address Phone 4 i r k and w A Q-8. 4 6923 Upstream Drainage Basin Size 3 AC 425) 821 -8448 PART 3 TYPE OF PERMIT APPLICATION PART 4 OTHER PERMITS ri Subdivision 1--1 DOF/G HPA ri Shoreline Management 1 1 Short Subdivision I 1 COE 404 Rockery 0 Grading I 1 DOE Darn Safety n Structural Vaults 1 ] Commercial I I FEMA Floodplain I I Other 1 xl Other Manufactured/Modular I I COE Wetlands 11 HPA Home Community PART 5 SITE COMMUNITY AND DRAINAGE BASIN . Community Drainage Basin Cedar River PART 6 SITE CHARACTERISTICS 1 1 River I I Floodplain 1 1 Stream 1 I Wetlands LI Critical Stream Reach 1 1 Seeps/Springs 1 Depressions/Swales r i High Groundwater Table I I Lake I xl Groundwater Recharge 1 1 Steep Slopes P 1 Other l I Lakeside/Erosion Hazard PART 7 SOILS Soil Type Slopes Erosion Potential Erosive Velocities Everett Variable Low Low I Additional Sheets Attatched King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET ART 8 DEVELOPMENT LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT 0 Ch.4-Downstream Analysis I 1 f I I 1 I I I j Additional Sheets Attatched PA•T 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTION x 1 Sedimentation Facilities I x I Stabilize Exposed Surface x 1 Stabilized Construction Entrance 7 Remove and Restore Temporary ESC Facilities l x I Perimeter Runoff Control 1 x I Clean and Remove All Silt and Debris 1 Clearing and Grading Restrictions I x 1 Ensure Operation of Permanent Facilities 1 Cover Practices I 1 Flag Limits of NGPES I xI Construction Sequence I I Other I= Other PA• 10 SURFACE WATER SYSTEM .. I 1 Grass Lined Channel I I Tank x 1 Infiltration Method of Analysis l xl Pipe System I I Vault I I Depression S . B . U . H . I l Open Channel I I Energy Dissapator 1 I Flow Dispersal Compensation/Mitigation I Dry Pond I I Wetland I I Waiver of Eliminated Site Storage 1 x1 Wet Pond I I Stream l I Regional Detention Brief ..)escriptionof System Operation Stormwater generated on-site will be infiltrated and off-site tributary areas will be bypassed . Facility Related Site Limitations 1 I Additional Sheets Attatched Refer ince Facility Limitation PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS May require special structural review) x I Drainage Easement Cast in Place Vault 0 Other I 1 Access Easement 1 1 Retaining Wall I 1 Native Growth Protection Easement 11 Rockery>4'High I x 1 Tract I Structural on Steep Slope I I Other 14 SIGNATURE OF PROFESSIONAL ENGINEER I or a civil engineer under my supervision have visited the site. Actual Asiteconditionsasobservedwereincorporatedintothisworksheetandthe z/N//pr attatcliments. To the best of my knowledge the information provided here i a accurate.sie r. 1/90 TABLE OF CONTENTS Page INTRODUCTION 1 VICINITY MAP 1 DRAINAGE CONCEPT 2 CITY OF RENTON AQUIFER PROTECTION AREAS EXHIBIT 3 DOWNSTREAM ANALYSIS 5 DOWNSTREAM ANALYSIS EXHIBIT 6 DETENTION CALCULATIONS 7 INFILTRATION PONDS C AND B 10 Developed Condition Hydrographs for Area Tributary to Pond C 10 Infiltration Ponds C and B Level Pool Routing 10 Live Storage 11 Water Quality 11 CONVEYANCE CALCULATIONS 12 EMERGENCY OVERFLOW PIPE CONVEYANCE CALCULATIONS 16 POND C TO POND B CONVEYANCE CALCULATIONS 17 EMERGENCY OVERFLOW SPILLWAY 18 RISER SIZING CALCULATION 18 EROSION CONTROL 18 APPENDIX SCS Soils Map Table 3.5.2 B—SCS W.Washington Runoff Curve Numbers 2, 10,25,& 100-Year Isopluvials Times of Concentration Exhibit,Basin 1 Water Works Output Table 4.3.3B—Coefficients for the Rational Method"iR"-Equation Table of Flows Used for Hydraulic Grade Line Calculations for Each Catchment Area Hydraulic Grade Line Calculations Hydrogeologic&Geotechnical Services/Report Addendum prepared by Geo Engineers,Inc.,April 6, 1995 Hydrogeologic&Geotechnical Services/Report prepared by Geo Engineers,Inc.,October 24, 1994 Preliminary Geotechnical Report prepared by CH2M Hill,May, 1988 Preliminary Hydrogeologic&Geotechnical Report prepared by Golder Associates,January, 1988 Level 1 Drainage Study and Preliminary Storm Drainage Calculations for Cedar Crest Manufactured/Modular Home Community prepared by Barghausen Consulting Engineers,Inc., Revision Dated November 4, 1994 Hearing Examiner's Report and Decision/File No.LUA-95-023,CU/V/MHP/ECF,May 23, 1995 In Pocket at End of Report Pipe Tributary Area Exhibit,Phases 3&4 STORM DRAINAGE REPORT FOR CEDAR CREST—Page i Phases 3&4 INTRODUCTION The proposed project is to construct a 401 site manufactured/modular home community on approximately 127 acres located north of and adjacent to Maple Valley Road (State Route 169) and south of N.E. Third Street. The project is separated into four construction phases. This report has been prepared to address storm drainage design for Phases 3 and 4. See the report titled "Cedar Crest — Phases I & II — Storm Drainage Report"for storm drainage design and analysis related to Phases 1 and 2. The site is bordered on the west by the recently constructed extension of Edmonds Avenue N.E. and the Plat of La Colina. The site is bordered on the east and northeast by a King County facility. More generally, the site is located in Section 16, Township 23 North, Range 5 East, W.M. in the City of Renton, King County,Washington. Please refer to the Vicinity Map located below. Approximately 85 acres of the site will be developed, while 42 acres will remain native. The site has been used as a gravel pit, which has been mined of most of the useful coarse gravel materials. The underlying foundation material is primarily fine to coarse-grained glacial outwash, which allows for good infiltration of surface water. A detailed description of the on-site soils can be found in the Hydrogeologic and Geotechnical Services/Report prepared by Geo Engineers, Inc. in October, 1994. This report is located in the Appendix. NF PARK £R k 0 m GN= 51 NE 4171 sr NF 30 ifr GREENi4000 CEJAE1ERY CITY OF RENTON11.k...SITE 1-'-\-( 1‘ • P a VICINITY MAP Not to Scale STORM DRAINAGE REPORT FOR CEDAR CREST—Page 1 Phases 3 &4 DRAINAGE CONCEPT The storm drainage system for the proposed project was designed with reference to standards found within the 1990 King County Surface Water Design Manual (KCSWDM) and as shown on the Grading & Utility Plans that accompany this report. Currently the majority of the on-site and off-site (upstream) stormwater infiltrates into the ground. The remainder is conveyed,through channels that were constructed as shown on the Grading/Temporary Erosion and Sedimentation Control Plans (previously approved by the City of Renton), to a Type II catch basin located approximately 500 feet south of the northwest corner of the site. From this structure, the water flows via a 30-inch underground pipe to an open basin that is located just outside the northwest corner of the site. A description of the existing conveyance system downstream from this point can be found in the Downstream Analysis section that follows this section. The site lies within two separate City of Renton Aquifer Protection Zones (see City of Renton Aquifer Protection Areas on the following page). The boundary line between the two zones runs east to west across the property, segmenting the southern portion of the property into APA Zone 1, while the northern portion is classified as APA Zone 2. This division line is also shown on the Pipe Tributary Area Exhibit,located in the Appendix. Per the Conditions of Approval for Cedar Crest (see Hearing Examiner's Report and Decision located in the Appendix), all of the stormwater generated on-site must be infiltrated. Since infiltration of stormwater is restricted within APA Zone 1, all of the infiltration facilities for this project have been sited within APA Zone 2. The site has been divided into two basins, with Basin#1 covering the northern portion of the site and both Phases 1 and 2 of the project. Basin#2 covers the remainder of the site, and is coincident with Phases 3 and 4 of the project. The areas tributary to each sub-basin within Basin #2 can be seen on the Pipe Tributary Area Exhibit(see Appendix). This report will focus specifically on the storm drainage issues of Basin#2. The stormwater generated within Basin#2 will be collected in a tightline conveyance system and directed to the existing water quality/detention/infiltration facility,located in the middle of the site,within the overhead power easement that bisects the site, hereafter referred to as Pond C. There is also an additional detention/infiltration facility located in Basin#1,hereafter referred to as Pond B, which receives stormwater exclusively from Basin#2. The stormwater will first enter a three-celled wetpond that will provide water quality enhancement prior to the stormwater entering infiltration Pond C. Once the level pool in Pond C reaches a certain elevation, some of the additional flows will be conveyed to infiltration Pond B. The infiltration ponds will provide live storage detention to allow the 2, 10,and 100-year/24-hour storm events to be released entirely through infiltration. 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Y:Vti:r.4 4'4••I••b,+.1 r .;; Jy i.-.:,..:... s ':ti•>-•hv:{;4rC•?:\%;\•ter,•'•;•.•a'°`rfv,•'j,1zYy.v;%:y tiv.,},:j •. •:ti:}. y'' r w:•.•:.;. .•. .,.:J. OV.•'•,N;.vj' W.C v 'y;'1D C.,:1r•s i .i•:..; h ec .:=/•• Irrr es p *.:^.t:%.x, rrt• :Ai;" v:,:5:%:•:•... 4u ::ysyiCJ••Y 10' a V :. .....J ...-,.•.••:.,Jv.,.•rr•••:•V:• JWJ•::•, f LS.•[•:T'O••••?V0..'Ar,.:.• J ; ::;; .:• ti :1::::v::..• TrStW: J# Lti+ :.. J .•j :•.: v:• .:: • 1i ' I s Wn t.':14:.h1i 1il.: :y•:.. ,:> • i •:m J a• o ?' C 1{AFLµ{%,74 0 2 5 O t 0 O O A r. 1 1 k Ju 7r r... o' r, 2 r+rt AMgr ra ar—.tS 1 r K0"1.1!fHi i M • k41tla u s WN.n Oil T•1 hllicd S.reic.t CITY OF RENTON CITY LIMITS aP^,... wdti PRODUCTION WEL 4 2 i, u1997"'^•• AQUIFER PROTECTION AREAS The goal of this proposed drainage system is to provide infiltration in order to recharge groundwaters, to prevent adverse impacts to downstream areas,and to maintain the overall hydrologic balance of the site and surrounding area. Currently the off-site (upstream) stormwater (0.95 acres), the on-site generated stormwater that does not infiltrate, and some of the groundwater base flows contribute to the downstream flow that discharges at the northwest corner of the site. In order to maintain this flow, the off-site upstream) flows will be collected by a gravel trench drain. It will follow the toe of the slope that runs along the northern property line of Basin#2. Stormwater flows from both above and below ground will be captured by this system and channeled to the emergency overflow pipe. They will then combine with bypass flows from Basin#1,and be conveyed to the site's natural discharge point. The Conditions of Approval questioned how the project site and neighboring areas would be affected by infiltrating stormwater in the infiltration ponds rather than distributing it over the entire site. It appears that the stormwater that infiltrates in the existing condition, both on-site and off-site (upstream), flows naturally towards the northwest corner of the site. In our opinion, it appears that the stormwater infiltrated on-site in the developed condition will follow the same general flow patterns toward the northwest corner of the site, and will help to maintain the existing downstream flows. This is confirmed by the location of the infiltration facilities, where both infiltration ponds (Pond B and Pond C) are situated back several hundred feet from the west property line of the site to allow the infiltrated flows to spread out as the flows follow the apparent westerly gradient and so that they more closely match the existing condition. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 4 Phases 3 &4 DOWNSTREAM ANALYSIS As described previously, the stormwater generated on-site will all be infiltrated on-site. However, an Emergency Overflow Pipe system has been designed and installed to convey the stormwater that would be discharged by Pond C and Pond B (and/or also Pond A which serves Phases 1 and 2) in the event of failure. This pipe is also designed to convey the runoff from the off-site (upstream) tributary areas (both Basin #1 and#2) and the on-site bypass areas (Basin#1). The 30-inch diameter pipe follows the alignment of Road A (Cedar Crest Parkway) until it makes a jog to connect to a type II catch basin with solid cover that is located approximately 500 feet south of the northwest corner of the site. This structure is labeled as CB OV-1A on both the Pipe Tributary Area Exhibit — Phases 1 & 11 (see Appendix of the Storm Drainage Report for Phases 1 and 2)and the Downstream Analysis Exhibit(next page). From this structure, the stormwater continues through approximately 157 feet of 30-inch underground H.D.P.E.pipe to an open pond that is located just outside the northwest corner of the site. Stormwater from this basin overflows into a 48-inch diameter corrugated metal pipe riser and flows through approximately 168 feet of 48-inch corrugated metal pipe at roughly a 5 percent slope. This pipe discharges into a drainage channel that is well defined and heavily vegetated, and travels westerly for approximately 300 feet. Here it discharges into an open pond that is approximately 100 feet by 50 feet and approximately 3 to 5 feet deep. The pond is located along the south margin of N.E. 3'd Street, and east of Blaine Avenue N.E., adjacent to the entrance into the Mount Olivet Cemetery. The stormwater exits this pond through an overflow structure with a birdcage, and enters into a system of approximately 1,250 feet of pipe (18" followed by 24") that runs along the southern margin of N.E. 3rd Street, eventually discharging into a system near I-405. By this point,the Cedar Crest site makes up less than 10 percent of the contributing basin,and so drainage systems, which were further downstream, were not studied. This downstream flow path was analyzed while conveying heavy rains during a site visit by Triad Associates on October 13, 1998. The drainage course was working properly and no signs of erosion or flooding problems were evident. A similar summary of downstream conditions is in the Level 1 Drainage Study and Preliminary Storm Drainage Report by Barghausen Consulting Engineers,Inc.,located in the Appendix. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 5 Phases 3 &4 mINENNEMII o gyp i Patj I ti Mt, l co CA 4/ MI Mire n 111IITEDN R a DOWNSTREAM ANALYSIS EXHIBIIT C 111 . go Sh le 1 Hil 411CEDARCRESTfqiJffIIbiø le; DETENTION CALCULATIONS Basin #2, as shown on the Pipe Tributary Area Exhibit in the Appendix, includes the on-site developed areas of Phases 3 and 4 of the project,as well as the approximately 4-acre future park area in the southwest corner of the site. The specific areas, which were included in the facility sizing calculations, have been summarized in the table below. The table shows the areas calculated for each of the different land covers in the developed condition for the areas tributary to Pond C, the Basin #2 conveyance system, and the Emergency Overflow Pipe. SUMMARY OF AREAS USED IN CALCULATIONS Location Impervious Pervious Pond C Basin#2 Overflow Area Area Sizing Convey- Pipe acres) (acres) ance Sizing CN=98 CN=68 System Sizing' Interior Roads&Sidewalk 5.35 X X X Impervious Area on Lots(2,876 s.f./lot* 200 lots)13.20 X X X Basin#2 Pervious Areas(Lots,landscaping,etc.) 13.88 X X X Detention/Infiltration Pond C(Incl.surrounding area) 1.85 X X Water Quality Pond C 0.52 X X Detention/Infiltration Pond B 0.61 X X Pervious Future Park Area(S.W.corner of basin) 3.95 X X X Off-site Bypass Area(Along northern basin boundary)0.95 X Basin#1 Areas(Incl.bypass and off-site tributary areas) 25.97 31.50 X Acreage Totals 39.36 32.43 97.78 Total Impervious 19.07 18.55 45.04 Total Pervious 20.29 13.88 52.74 Existing Conditions Tributary Area: 39.36 Ac. (area tributary to Pond C) 0.61 Ac.(detention/infiltration Pond B) 38.75 Ac. The totals for this column represent the areas used in the hydrograph flow calculations. For the Future Park area,which is also marked with an"X"in this column,the flows were calculated using the Rational Method. The detention calculations were performed using Engenious Systems Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A(User 1) 24-hour rainfall distribution. Separate S.C.S. curve numbers were used for the impervious and pervious portions of the site. Using the onsite existing condition hydrographs, the allowable release rates were determined for the site in accordance with City of Renton standards. Developed condition hydrographs were then generated for the bypass areas in order to verify that the developed bypass flows did not exceed the pre-developed peak runoff rates for each of the 2, 10, and 100-year, 24-hour storm events. This analysis can be found in the Cedar Crest—Phases I&II—Storm Drainage Report. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 7 Phases 3 &4 According to Core Requirement #3, Section 1.2.3 of the KCSWDM, "Three basic methods for peak rate runoff control are possible: detention, retention, and infiltration." This project proposes to use infiltration to meet this core requirement. Further in this section of the KCSWDM under the heading `Infiltration Facilities', it states that"the factors of safety for infiltration systems are incorporated within the methods of analysis and design standards described in Section 4.5." In the Hydrogeologic and Geotechnical Services/Report, Geo Engineers, Inc. recommended an effective percolation rate for both Pond C and Pond B of 4 inches per hour. This recommendation was based on the following analysis, which is taken from their report, which is located in the Appendix. "Stormwater infiltration rates for the site soils were calculated based on the grain-size distribution of select soil samples and their corresponding soil textures. The U.S. Department of Agriculture Textural Triangle provided in the Stormwater Management Manual for the Puget Sound Basin, published in February 1992, was used to determine the soil textures and the infiltration rate. Representative soil samples were collected at the elevations of the proposed infiltration pond bottoms below the filter. The theoretical stormwater infiltration rates for the soil samples analyzed is about 8 inches per hour. This rate of infiltration would occur until the underlying soil is saturated and the water table is mounded above the bottom of the pond. When the top of the mound is above the bottom of the pond,the effective infiltration rate is equivalent to the dissipation rate of the mound. Important factors affecting the dissipation are the size and shape of the infiltration area, depth to the water table, and other factors." The report goes on to specifically address the infiltration rate for the areas of Pond B (identified in their report as 'area B') and Pond C (identified in their report as 'area C'). "For percolation area B, we calculate a dissipation rate of 4 to 6 inches per hour. Based on this, a design percolation rate of 4 inches per hour is recommended. The dissipation rate for area C is calculated to be 4 inches per hour,and a percolation rate of 4 inches per hour is recommended." This infiltration rate is less than the maximum rate of 8 inches per hour for this Vashon glacial outwash soil as specified in Table 4.5.2 of the KCSWDM. Due to the KCSWDM's Section 4.5 required factor of safety of 2.0 (although the EPA test was not used, 2.0 is the more conservative of the two factors specified in the KCSWDM),an infiltration rate of 2 inches per hour was used for these detention calculations. The stormwater detention and infiltration needs of Basin#2 are served by two independent ponds which are connected by a 12" storm pipe conveyance system. Pond C serves as the primary water quality/detention/infiltration facility, while Pond B provides additional detention and infiltration capacities. Pond C provides detention and infiltration in the most northern cell of the pond. Additional detention volume is provided above the live-dead interface in the three wet pond cells. Pond B is entirely a detention and infiltration pond,as all of the flows entering it will have already been treated by the wet pond portion of Pond C. A catch basin containing a riser control structure (SDMH 5-5) is located at the north end of Pond C. It receives flows from Pond C via a single 12"pipe and once the level pool in Pond C reaches an elevation of 246.30, water begins discharging through the riser via a single 4.5" orifice and is conveyed to Pond B STORM DRAINAGE REPORT FOR CEDAR CREST—Page 8 Phases 3& 4 through a 12" pipe. Flows from Pond C can also be discharged through an emergency overflow structure SDMH 5-7) that is located in the northwest corner of Pond C. This catch basin has a rim elevation set at the 100-year maximum water surface elevation of Pond C. If the water surface of Pond C exceeds the design maximum water surface of 250.80, a 24" secondary discharge pipe will convey the flows from SDMH 5-7 to a 30"emergency overflow pipe, located under Cedar Crest Parkway, which discharges at the site's natural discharge point (as described previously in the Downstream Analysis). Under normal circumstances,however,the riser discharge structure serves as a flow splitter,allowing just a portion of the storm water flows to be conveyed to Pond B while the remainder are infiltrated in Pond C. SDMH 5-5 was designed with a rim elevation of 254.15 and the top of the riser was set at 251.65. If the entire Basin 2 100- year storm flow were to be discharged through SDMH 5-7 with the water surface of Pond C already at the maximum water surface elevation of 250.80, the flow through this structure would cause the pond to crest 0.60 feet higher to 251.40. In order to ensure that the riser in SDMH 5-5 would never be overtopped by the water surface of the pond, the top of the riser was set 0.25 feet above this elevation at 251.65. In accordance with King County requirements,the rim of the catch basin containing the riser was then set 2.50 feet above the top of the riser,at 254.15. Pond B receives stormwater exclusively from the 12" storm pipe that conveys the outflow of the riser control structure in SDMH 5-5. It is designed to discharge all of the runoff that enters it via infiltration. However, it also has an emergency overflow structure (CB 1-54A) located in its west corner. The rim of this structure is set at 246.00,the design maximum water surface for Pond B. This structure has a 24"outlet pipe,which conveys any overflow to the 30"emergency overflow pipe,located under Cedar Crest Parkway Road A). Ponds B and C have been as-built surveyed, providing us with accurate information with regards to their storage capacity. Developed condition hydrographs were generated for each of the 2, 10, and 100-year,24- hour storm events for the 39.36 acres of area tributary to Pond C. They were then routed through Pond C and Pond B, verifying that the volume of the as-built ponds was sufficient, as shown in the Level Pool Summary shown below. For the following calculations,the total precipitation for the 2, 10,and 100-year,24-hour storm events were found to be 2.00",2.90",and 3.90"respectively,as shown on the respective King County isopluvials in the Appendix. The curve numbers used for the different landcovers are shown on Table 3.5.2E — S.C.S. Western Washington Runoff Curve Numbers, located in the Appendix. All of these exhibits are located in the Appendix of this report. A summary of the detention/infiltration pond calculations is provided below. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 9 Phases 3&4 INFILTRATION PONDS C AND B Developed Condition Hydrographs for Area Tributary to Pond C Total Area=39.36 Ac(See the Summary of Areas table) Impervious Area = 19.07 Ac @ CN=98 Pervious Area =20.29 Ac @ CN=68 (lawn) The following time of concentration figure is based on an approximate flow path from the east end of Basin 2 to Pond C via the proposed conveyance system. Please reference both the Pipe Tributary Area Exhibit see Appendix) and the Grading & Utility Plans(that accompany this report) for the basis of the following values used in the computation of the time of concentration. Time of Concentration=21.19 minutes Reach 1: 150 ft Sheet Flow @ 8.8%, 'n' =0.150(lawn) Reach 2: 340 ft Shallow Concentrated Flow @ 2.5%,`ks' = 11 (lawn) Reach 3: 569 ft Channel Flow @ 3.0%,`ks' =42(pipe) Reach 4: 478 ft Channel Flow @ 1.0%,`ks'=42(pipe) Reach 5: 289 ft Channel Flow @ 2.0%,`ks' =42(pipe) Reach 6: 839 ft Channel Flow @ 1.5%,`ks' =42 (pipe) Reach 7: 434 ft Channel Flow @ 1.0%,`ks' =42 (pipe) Pond C Tributary Area Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] 2-Year 2.00 7.28 137,152 480 10-Year 2.90 11.56 227,141 480 100-Year 3.90 17.71 337,856 480 Infiltration Ponds C and B Level Pool Routing The following level pool table summary represents the results of routing the Pond C tributary area 2, 10, and 100-year hydrographs (for the developed condition) through the network of infiltration Pond C and Pond B in order to check the adequacy of the constructed ponds. The flow values shown below for the flow into Pond B were generated by using Water Works to model the flow through the 4 V2"orifice in the riser in SDMH 5-5. Hydrographs were generated for these flows which are conveyed to Pond B as its only inflow. Please refer to the Water Works output located in the Appendix for the hydrograph data, hydrograph summary table,and actual program output. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 10 Phases 3&4 INFILTRATION POND C-LEVEL POOL TABLE SUMMARY Description Inflow Storage Discharge P.Stage Volume Outflow P.Time CFS]ID ID FT]CF] [CFS] [Min] Pond C-2 Year Developed 7.28 PONDC COMB2 247.02 52,161 1.336 1020 Pond C- 10 Year Developed 11.56 PONDC COMB2 248.72 106,535 1.873 1450 Pond C- 100 Year Developed 17.71 PONDC COMB2 250.84 187,512 2.385 1460 INFILTRATION POND B-LEVEL POOL TABLE SUMMARY Description Inflow Storage Discharge P.Stage Volume Outflow P.Time CFS]ID ID FT]CF] [CFS] [Min] Pond B -2 Year Developed 0.47 PONDB COMB3 242.15 9,653 0.334 1590 Pond B - 10 Year Developed 0.86 PONDB COMB3 244.88 29,961 0.550 1950 Pond B - 100 Year Developed 1.02 PONDB COMB3 246.02 40,569 0.654 2130 Live Storage As shown in the Level Pool Summary above,Pond C has a maximum water surface elevation of 250.84 and provides 187,512 cubic-feet of storage at this elevation. For this Water Works analysis, the as-built volumes of both Pond C and Pond B were reduced to account for a 30% factor of safety. The elevations shown in the Level Pool Summaries above are based on these reduced pond volumes. Infiltration Pond C has actually been constructed to provide 241,490 cubicfeet of storage at the design maximum water surface elevation of 250.80,or 129%of the required storage volume. Also as shown above,Pond B has a maximum water surface elevation of 246.02 and provides 40,569 cubic- feet of storage at this elevation. Infiltration Pond B has actually been constructed to provide 52,482 cubic feet of storage at the design maximum water surface elevation of 246.00, or 129%of the required storage volume. Water Quality Water quality will be provided through the use of dead storage. According to King County standards, the required water quality volume is equal to the total runoff from the developed condition 24-hour design storm event using 33%of the 2-year,24-hour precipitation. 0.33)(P2yr)=(0.33)(2.00 in)=0.67 inches Water Quality Hydrograph Summary Storm Precip. Peak Flow Volume Time of Peak Event in] cfs] ft3] min.] Water Quality 0.67 1.94 32,887 480 The required volume to be used for water quality storage is 32,887 cubic feet. The three-celled wet pond portion of Pond C has actually been constructed to provide 46,911 cubic feet of water quality storage from elevation 243.60 to 246.60). The wet pond is also required to have a surface area of at least 1%of the developed impervious area. The impervious area in the developed condition is 19.07 acres,therefore 0.19 acres(or 8,276 square feet)of wet pond surface area is required. The wet pond will have a surface area at elevation 246.60 of 19,814 square feet. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 11 Phases 3& 4 CONVEYANCE CALCULATIONS In accordance with the King County Surface Water Design Manual,the conveyance system was designed to provide a minimum of six inches of freeboard within each catch basin for the 25-year,24-hour design storm event. The system was then checked with the 100-year storm event to ensure that no overtopping occurred. The hydraulic grade line calculations were performed using Eagle Point Software's computer program Storm Sewers. The program determines the flow rate in each pipe and then performs a standard step hydraulic analysis on the pipe network.The methodology used for non-uniform flow analysis is the standard step energy balance. This procedure is used to determine the hydraulic grade line throughout the pipe network and is identical to that used for any open channel water surface profile. The steady state energy equation (Bernoulli equation) is used between upstream and downstream sections of each pipe in the network. The friction slope is then calculated by applying Manning's equation at the upstream and downstream ends and averaging the slope between them. The program then performs three iterations to pinpoint the hydraulic grade line. Computations begin at the most downstream pipe and continue in an upward direction. The 25 and 100-year flows were determined for Basin #2 using Engenious System Inc.'s hydrology program Water Works. Hydrographs were developed using S.B.U.H. methodology with a King County Type I-A(User 1)24-hour rainfall distribution. The areas of Basin#2 that are tributary to the conveyance system are summarized in the Summary of Area Calculations table presented earlier in this report. Separate S.C.S.curve numbers were used for the impervious and pervious portions of the basin. The resultant flows were distributed to each catch basin structure, based on the individual area tributary to each structure, as shown on the Pipe Tributary Area Exhibit located in the Appendix. Using Water Works software,the following 25 and 100-year peak flows were determined: Total Fut.Park Area2 Q25 Qloo Tailwater Tailwater Area Areal (Acres) (CFS) (CFS)Elev. Elev. Acres) (Acres) 25-Year 100-year 36.38 3.95 32.43 13.63 16.36 249.76 250.80 The area of the naturally landscaped park that will be developed in the future was included in the conveyance analysis by computing baseflows using the Rational Method and are shown on the Pipe Tributary Area Exhibit as flows(Q). 2 For this area,the majority of the basin,the area tributary to each catch basin was measured,and then the S.B.U.H.flows for each catch basin were calculated based on each structure's proportionate area. The S.B.U.H.flows for this area are shown in this table and do not include the flows from the future park area.These flows were input into Storm Sewers as individual flows for each catch basin as shown on the Table of Flows Used for H.G.L. Calculations for Each Catchment Area in the Appendix. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 12 Phases 3&4 The majority of the basin is very consistent in the type and proportion of the land covers found in the tributary area of each catch basin. However,the area that will be developed in the future as a park will be left predominantly in its natural state,except for the construction of some meandering walking trails. Since this area will effectively be without any impervious area,25 and 100-year flows were calculated separately for it using the Rational Method,as summarized below. The time of concentration was calculated to be less than the minimum allowed by King County,and so the minimum value of 6.3 minutes was used for these Rational Method calculations. Location Impervious Pervious T. Peak Peak Qzs Q100 Area Area (minutes) Rainfall Rainfall (cfs) (cfs) acres) (acres) Intensity Intensity In) Iioo) Future Park Area 0.00 3.95 6.30 2.73 3.19 2.16 2.52 Q=E(CxIxA) In order to allow for flexibility in the future design of the park area,the runoff coefficients used in the above equation to obtain the flow values shown in the table above were based on an assumption of half of the park being developed as pervious lawn,C=0.25 (lawns),and the other half being left as naturally forested,C=0.15 (light forest). This is a conservative assumption since,as mentioned previously,most of the park area will likely remain in its native state. The peak rainfall intensities(I)used in the above equation are provided in the table above and are detailed as follows,where the values for PR and Tc were provided previously and aR and bR are per Table 4.3.3.3B in the KCSWDM(also included in the Appendix): I25=PR x(aR x Tc-( b`))= 3.40 x(2.66 x(6.30) 40.65)= 2.73 PR x(aR x Tc.(b`))=3.90 x(2.61 x(6.30).063)= 3.19 The flows shown above were assumed to be tributary to CB 3-18. The 100-year flow is shown on the Pipe Tributary Area Exhibit located in the Appendix. The following are the 25-year and 100-year freeboard tables for the on-site conveyance system,which show that all of the catch basins have sufficient freeboard. Please refer to the Hydraulic Grade Line Calculations exhibit,in the Appendix of this report,for actual computer output. STORM DRAINAGE REPORT FOR CEDAR CREST—Page 13 Phases 3 &4 FREEBOARD TABLE 25-yr and 100-yr Location Catch Rim Elev. HGL Elev. Freeboard HGL Elev. Freeboard Basin ft) 25-yr(ft) 25-yr(ft) 100-yr(ft) 100-yr(ft) Road A CB 3-1 253.50 249.86 3.64 250.94 2.56 CB 3-2 254.70 249.95 4.75 251.07 3.63 CB 3-3 253.58 250.05 3.53 251.21 2.37 CB 3-4* 254.39 252.38 2.01 252.75 1.64 CB 3-6* 255.86 253.82 2.04 254.16 1.70 CB 3-8* 257.36 255.24 2.12 255.55 1.81 CB 3-10* 259.50 257.30 2.20 257.58 1.92 CB 3-12 260.73 258.30 2.43 258.57 2.16 Road I CB 3-13 260.63 258.31 2.32 258.57 2.06 CB 3-14 261.59 259.54 2.05 259.79 1.80 CB 3-15 261.59 260.06 1.53 260.53 1.06 CB 3-16 265.19 262.64 2.55 263.14 2.05 CB 3-17 274.53 271.88 2.65 272.08 2.45 CB 3-18* 282.31 280.01 2.30 280.15 2.16 Road J CB 3-20* 274.53 271.89 2.64 272.09 2.44 Road I CB 3-22* 265.07 262.77 2.30 263.33 1.74 CB 3-24* 267.38 264.75 2.63 264.85 2.53 CB 3-26* 273.18 270.41 2.77 270.50 2.68 CB 3-28 276.80 273.94 2.86 274.02 2.78 CB 3-29 277.67 274.80 2.87 274.87 2.80 CB 3-30* 279.78 276.82 2.96 276.88 2.90 CB 3-32* 282.75 279.71 3.04 279.75 3.00 CB 3-34* 285.19 282.01 3.18 282.05 3.14 Road A CB 3-35 252.86 250.16 2.70 251.37 1.49 CB 3-36 252.86 250.26 2.60 251.52 1.34 CB 3-37 253.09 250.36 2.73 251.67 1.42 Road K CB 3-38 252.28 250.47 1.81 251.81 0.47 CB 3-39 252.28 250.57 1.71 251.96 0.32 CB 3-40* 253.14 250.87 2.27 252.40 0.74 CB 3-42* 256.07 253.62 2.45 253.82 2.25 CB 3-44* 259.01 257.19 1.82 257.72 1.29 CB 3-47* 261.95 259.97 1.98 260.43 1.52 Road I CB 3-49 263.98 261.89 2.09 262.30 1.68 CB 3-50* 265.48 263.31 2.17 263.70 1.78 CB 3-52 266.48 264.15 2.33 264.90 1.58 CB 4-1 267.48 264.95 2.53 266.04 1.44 CB 4-2 269.12 265.72 3.40 267.15 1.97 CB 4-3 271.75 269.14 2.61 269.24 2.51 CB 4-4 274.37 270.79 3.58 270.88 3.49 CB 4-5* 279.23 276.27 2.96 276.33 2.90 CB 4-7 280.73 277.70 3.03 277.75 2.98 CB 4-8 282.23 279.08 3.15 279.12 3.11 CB 4-9 282.53 279.31 3.22 279.34 3.19 CB 4-10 284.71 281.44 3.27 281.47 3.24 Inlets were not modeled. The inlets of the main line were not modeled because the main line generally had in excess of 1 ft of freeboard for the 25-year event. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 14 Phases 3 & 4 FREEBOARD TABLE (continued) 25-yr and 100-yr Location Catch Rim Elev. HGL Elev. Freeboard HGL Elev. Freeboard Basin ft) 25-yr(ft) 25-yr(ft) 100-yr(ft) 100-yr(ft) Road M CB 4-11* 274.14 271.14 3.00 271.19 2.95 CB 4-13 275.97 272.76 3.21 272.79 3.18 CB 4-14* 277.34 274.05 3.29 274.07 3.27 Road L CB 4-16* 268.80 265.99 2.81 267.54 1.26 CB 4-18* 270.50 267.23 3.27 267.83 2.67 CB 4-20 271.65 268.30 3.35 268.42 3.23 Road N CB 4-21 271.27 269.06 2.21 269.16 2.11 CB 4-22 271.27 269.30 1.97 269.40 1.87 CB 4-23 272.64 269.95 2.69 270.04 2.60 CB 4-24* 275.67 272.94 2.73 273.03 2.64 CB 4-26* 281.75 278.94 2.81 279.01 2.74 CB 4-28 286.30 283.37 2.93 283.43 2.87 CB 4-29* 289.34 286.36 2.98 286.42 2.92 Inlets were not modeled. The inlets of the main line were not modeled because the main line generally had in excess of 1 ft of freeboard for the 25-year event. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 15 Phases 3& 4 EMERGENCY OVERFLOW PIPE CONVEYANCE CALCULATIONS In accordance with the King County Surface Water Design Manual, the Emergency Overflow conveyance system is required to provide a minimum of six inches of freeboard within each catch basin for the 25-year, 24-hour design storm event. Additionally, while conveying the 100-year, 24-hour design storm event, overtopping of any of the catch basins is not allowed. As designed, the emergency overflow pipe was sized to provide a minimum of six inches of freeboard within each catch basin while conveying the 100-year, 24- hour design storm flows from both basins simultaneously. This was done to ensure that if both of these infiltration facilities were to fail,the flow could be adequately discharged off site to the natural downstream discharge point. For this analysis, hydrographs were developed using S.B.U.H. methodology,just as in the previous sections of this report. The hydrographs were created for the tributary areas of each basin separately,as summarized in the Summary of Area Calculations table presented earlier in this report and as shown on the Pipe Tributary Area Exhibit located in the Appendix. The computer program Storm Sewers was used to perform the actual hydraulic gradeline computations, following the same procedures used to check the adequacy of the primary conveyance system. The Emergency Overflow Pipe was analyzed for a theoretical failure scenario of the entire flow of Basin#2 being discharged at the outlet of Pond C while the entire flow of Basin #1 is discharged at the outlet of Pond A (Phases 1 and 2). Additionally, the entire flow being contributed to Pond B from Pond C was assumed to be entering the overflow pipe from Pond B. Therefore, the Pond B flow was accounted for twice, in order to conservatively verify the Emergency Overflow Pipe's ability to handle the overflow created by a failure occurring simultaneously in both Pond C and the discharge pipe from Pond C to Pond B. For this analysis,flow was also contributed from the bypass areas consisting of the slopes along the east side of the site and the offsite(upstream)tributary area along the east property line(Phases 1 and 2). The flows used for this hydraulic grade line analysis are detailed in the following table, which also lists the acreages of each tributary area. The tailwater elevation shown is the approximate elevation of the natural pond/stream at the discharge point of the Emergency Overflow Pipe in the northwest corner of the site. Area Qloo Tailwater Elev. Acres) (CFS) Basin#1 50.16 27.48 223.00(Outfall at off-site discharge point) Basin#1 Off-site Tributary Area 3.01 0.50 223.00(Outfall at off-site discharge point) Basin#1 N.E.Slope Bypass Area 4.30 0.71 223.00(Outfall at off-site discharge point) Basin#2 39.36 17.71 223.00(Outfall at off-site discharge point) Basin#2 Off-site Bypass Area 0.95 0.14 223.00(Outfall at off-site discharge point) Basin#2 Pond B Discharge N/A 1.02 223.00(Outfall at off-site discharge point) STORM DRAINAGE REPORT FOR CEDAR CREST—Page 16 Phases 3& 4 The following is the 100-year freeboard table for the Emergency Overflow Pipe, which summarizes the amount of freeboard available in each structure. The table shows that all of the catch basins have sufficient freeboard. Since sufficient freeboard is present for the 100-year event, the 25-year event was not included in the analysis. Please refer to the Hydraulic Grade Line Calculations exhibit, in the Appendix of this report,for actual computer output. FREEBOARD TABLE 100-yr Catch Basins Rim Elev. HGL Elev. Freeboard ft)100-yr(ft) 100-yr(ft) CB OV-1 243.71 224.43 19.28 CB OV-2 244.64 226.25 18.39 CB OV-3 242.39 228.08 14.31 CB OV-4** 242.40 233.66 8.74 CB OV-5** 246.09 238.58 7.51 CB OV-6 250.90 243.33 7.57 CB OV-7 252.30 244.39 7.91 POND C OVERFLOW 250.80 245.01 5.79 POND A OVERFLOW 241.00 239.31 1.69 POND B OVERFLOW 246.00 239.66 6.34 I These catch basins were numbered sequentially to make their order clearer. However,the plan set designations are different from the labels shown here. Indicates a junction between a branch and the main line. POND C TO POND B CONVEYANCE CALCULATIONS In accordance with the King County Surface Water Design Manual,the conveyance system between Pond C and Pond B was designed to provide a minimum of six inches of freeboard within each catch basin for the 25-year,24-hour design storm event. The system was then checked with the 100-year storm event to ensure that no overtopping occurred. Hydrographs for this pipe system were developed as a part of the facility sizing analysis that was completed using Water Works. A summary of the flow modeled through this analysis is shown below. Please refer to the Water Works output located in the Appendix for actual program output. The computer program Storm Sewers was used to perform the actual hydraulic gradeline computations,utilizing the same procedures used to check the adequacy of the primary conveyance system. Qioo Tailwater Elev. CFS) Flow from Pond C to Pond B 1.02 249.60(Pond B Maximum Water Surface) The following is the 100-year freeboard table for the conveyance system between Pond C and Pond B, which summarizes the amount of freeboard available in each structure. The table shows that all of the catch basins have sufficient freeboard. Since sufficient freeboard is present for the 100-year event, the 25-year event was not included in the analysis. Please refer to the Hydraulic Grade Line Calculations exhibit, in the Appendix of this report,for actual computer output. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 17 Phases 3 & 4 FREEBOARD TABLE 100-yr Catch Basin Rim Elev. HGL Elev. Freeboard ft)100-yr(ft) 100-yr(ft) CB 5-1 247.10 241.01 6.09 CB 5-2 247.46 241.48 5.98 CB 5-3 249.59 242.54 7.05 CB 5-4 250.77 243.08 7.69 CB 5-5 254.15 246.92 7.23 EMERGENCY OVERFLOW SPILLWAY Pond B will have an emergency spillway sized per figure 4.4.4 A of the 1990 K.C.S.W.D.M. This overflow route is in addition to the emergency overflow pipe that was discussed above. The spillway equation is: L= [Q/(3.21 x H312)]-(2.4 x H2) Where: Q= 100 year pond inflow H=Water depth over spillway(King County requires a minimum depth of 0.2 feet) L=Spillway length Using H=0.2 feet,the equation becomes: L=[Q/0.287]-0.5 L=[1.02 cfs/0.287]-0.1 L=3.45 feet(minimum) King County requires a minimum spillway width of 6 feet;therefore the spillway has been designed to meet this requirement. RISER SIZING CALCULATION The riser discharge structure located in Pond C was designed using the 1990 K.C.S.W.D.M.,specifically Figure 4.4.7 J,which specifies the following equation for this purpose: QRISER=3.782D2H12 Solving for the diameter of the riser `D',using the 100-year peak rate of flow from Pond C to Pond B (Q= 1.02 cfs),and the difference between the peak stage and the orifice elevation for the head `H' (250.80- 245.30=5.50 ft),showed that a 0.34 ft minimum riser diameter would be necessary. This verified that a 12-inch diameter riser will be satisfactory to discharge the 100-year peak outflow rate of 1.02 cfs. EROSION CONTROL Grading/Temporary Erosion and Sedimentation Control plans were prepared by Triad Associates in August 1995 and revised May 7, 1998. These plans, that were approved by the City of Renton, were designed to satisfy the erosion and sedimentation control requirements from initial grading through final build out. STORM DRAINAGE REPORT FOR CEDAR CREST-Page 18 Phases 3&4 APPENDIX STORM DRAINAGE REPORT FOR CEDAR CREST Phases 3 &4 0. v.:-...,: z. T.,.. it ._. L45, 175, 4:: 4 •: 5: • P iS: fiti...,? 4.... t. e4....;..... t. v.",/::... t.:. '/'•.. 4.: .... i. 41 • 4; igx.,,. V. ilL,::.......,„:.... ... 1::. J...., :". ',...: A• / 2 - . ;;; Zt•:':• tl:!,' 4;..- 1 th , •--' 7., ;/ 7 4 i / - :'.',"?.. 4,:•" 1. or,•;•,,••• • 7:,: iiiiikt i• •, • , • 4... 0 le f1/ 7.-\\ Ito, l':, •,,,. \•\••• 2•, ttk;• W - 1/ 41t. Atik ii:,,,:::. ist- t-- IF 71 h sl.' r '` •\ . 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IT, • . 41- II,, igi.,, I,,-- -.., u zdipti. 7e4str, Y- lilky. 4 7- -------:•• __,,,,.., , f i;. •• •-•• a 1 ,-' t .,,,,,- . ill .• , s s ,,...,, v. ta Ermift. 5, , I ;• Ili. 77";- •,... ,,...- I *. 4, 1t,;.•,•,,,....... m 4. 3 • iN k . s•-••,•,..:,.'$.,>.:. 410, ......_ Sji r.,•, r KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.2B SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type 1A rainfall distribution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION AB C D Cultivated Iand(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land:undisturbed or older second growth 42 64 76 81 Wood or forest land:young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area 68 80 86 90 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc.98 98 98 98 Open water bodies: lakes, wetlands, ponds, etc. 0 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, impervious condominiums, apartments, must be computed commercial business and industrial areas. 1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9,August 1972. 2) Assumes roof and driveway runoff is directed into street/storm system. 3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 3.5.2-3 1I/92 KING COUNTY, WASHINGTON. 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' lyr ca. .r?'-a I , !I l I i li rA Rh I I fig 2-YEAR 24-HOUR PRECIPITAT ION 1 Wiraktratte 3.4' ISOPLUVIALS OF 2-YEAR 24-HOUR ry ' p r- TOTAL PRECIPITATION IN INCHES neWri ,ilePIP 0 1 2 3 4 5 6 7 e Mlles w c , v n —or CV y . 1:300.000 3.5.1-8 6j 1/ KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1E 10-YEAR 24-HOUR ISOPLUVIALS 2.1 r1\ T 7 1P.f On-zi p.- _._. ltillrir ll/ 2 sin ag I wigiA c Al le011I I4 1FPrAl711 I ZS 27 :i IiiMPAai A N Nkiltig*I5N. P 1, •4., ,..ce' ao igV !! ry iklw i.\ -- e'''•„ '; .:k-,Iiii. 7.‘-' 1111:teirillir Anil fig,* .1I • i"' i z?* livEti e ce v.3.7 ti,irkiil NkVIIVlay Ail rili r4.- Ms , Nk 1 ._,iiitti 1 ... . 4.ze, , ,_\L: ,.. ... ,L...k , _ .. .. --..-00: -.4.1 , e..0,-- 1.' , : i. 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'' r NrAwieritit lir - 4- 1 , V&A iii ‘V•.' • At t 1M111:0.riWk Aft -. 1/4. • 100-YEAR 24-HOUR PRECIPITATION w e.,,: . ! ••• - ISOPLUVIALS OF 100-YEAR 24-HOUR pi. 5 % I .- _ 5.5 TOTAL PRECIPITATION IN INCHES O 0 1 2 3 4 5 6 7 8 Mlles 0. r3.5.1-13 O 1:300.000 1/90 Immillos se, :714`-- kt.....:••—.Py?";4f/..,%." . ..'",%.:f:' •'''' • \ 1 ‘ i ;• 1 \ 1 \ 1\1 ,. ...„„.-- ,..:.1,?:1,1 j(\ \,...../ ',..,,'kt..„ • I ) \.S\), t ii.... 9; .\ w.Si 7' .' i_ c-1—_ f^". w `i::r:, f y\ \ \, ;fit;-n4 A/.aww.;: S T_ Tr I 4 • pbi 13 1 1! . t"•d ,%1 i ii frs i 1.`` r r \ i" , r( j E fi f . ,;;9r1, 66;, ik1 f{,.:'::l'. 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O r #4>;y art w it yj' n rrrr N NO wa a'olm"a TIMES OF CONCENTRATION EXH/Bl/T r V I li 1 1/I 4 1 : BASIN 1 II:E E B 111111015CEDARCRESTgi .. a I y cueu .:: ',ECITYOFRENTOAL BASIN SUMMARY BASIN ID: B 1 NAME:2-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER' PERVIOUS AREA PRECIPITATION..: 2.00 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 7.28 cfs VOL: 3.15 Ac-ft TIME: 480 min BASIN ID: B2 NAME: 10-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 2.90 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 11.56 cfs VOL: 5.21 Ac-ft TIME: 480 min BASIN ID:B3 NAME: 25-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.40 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 14.54 cfs VOL: 6.46 Ac-ft TIME: 480 min BASIN ID: B4 NAME: 100-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 17.71 cfs VOL: 7.76 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 1 Phases 3&4 BASIN ID:Cl NAME: CONVEYANCE 25 YR.FLOWS SBUH METHODOLOGY TOTAL AREA..: 32.43 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.40 inches AREA..: 13.88 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 18.55 Acres CN..: 98.00 PEAK RATE: 13.63 cfs VOL: 5.87 Ac-ft TIME: 480 min BASIN ID: C2 NAME: CONVEYANCE 100 YR.FLOWS SBUH METHODOLOGY TOTAL AREA..: 32.43 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 13.88 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 18.55 Acres CN..: 98.00 PEAK RATE: 16.36 cfs VOL: 6.99 Ac-ft TIME: 480 min BASIN ID:WQ NAME:WATER QUALITY SBUH METHODOLOGY TOTAL AREA..: 39.36 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 0.67 inches AREA..: 20.29 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 19.07 Acres CN..: 98.00 PEAK RATE: 1.94 cfs VOL: 0.75 Ac-ft TIME: 480 min BASIN ID:OS 1 NAME: BASIN 2-OFF SITE BYPASS- 100 YR. SBUH METHODOLOGY TOTAL AREA..: 0.95 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..: USER1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 0.95 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 21.19 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.14 cfs VOL: 0.09 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 2 Phases 3 &4 BASIN ID: 1-100 NAME: BASIN 1 - 100-YR DEVELOPED SBUH METHODOLOGY TOTAL AREA..: 50.16 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USERI PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 24.19 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 12.11 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 25.97 Acres CN..: 98.00 PEAK RATE: 27.48 cfs VOL: 10.23 Ac-ft TIME: 480 min BASIN ID: 1-OS 1 NAME: BASIN 1 -OFF-SITE TRIBUTARY- 100 YR. SBUH METHODOLOGY TOTAL AREA..: 3.01 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USER 1 PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 3.01 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.50 cfs VOL: 0.29 Ac-ft TIME: 480 min BASIN ID: 1-BYP NAME:BASIN 1 -E.SLOPE BYPASS 100 SBUH METHODOLOGY TOTAL AREA..: 4.30 Acres BASEFLOWS : 0.00 cfs RAINFALL TYPE..:USERI PERVIOUS AREA PRECIPITATION..: 3.90 inches AREA..: 4.30 Acres TIME INTERVAL..: 10.00 min CN..: 68.00 TIME OF CONC..: 16.23 min IMPERVIOUS AREA ABSTRACTION COEFF : 0.20 AREA..: 0.00 Acres CN..: 98.00 PEAK RATE: 0.71 cfs VOL: 0.41 Ac-ft TIME: 480 min WATER WORKS OUTPUT FOR CEDAR CREST-Page 3 Phases 3 &4 HYDROGRAPH SUMMARY HYD. HYDROGRAPH PEAK TIME VOLUME AREA NUM. DESCRIPTION CFS] Min] CF] Ac] 1 2-YR.DEVELOPED FLOW 7.277 480 137,152 39.36 2 10-YR.DEVELOPED FLOW 11.561 480 227,141 39.36 3 25-YR.DEVELOPED FLOW 14.537 480 281,368 39.36 4 100-YR.DEVELOPED FLOW 17.706 480 337,856 39.36 5 WATER QUALITY FLOW 1.939 480 32,887 39.36 6 25-YR.CONVEYANCE FLOW 13.630 480 255,756 32.43 7 100-YR.CONVEYANCE FLOW 16.359 480 304,361 32.43 8 2-YR.POND C OUTFLOW 1.336 1020 137,152 39.36 9 10-YR.POND C OUTFLOW 1.873 1450 223,763 39.36 10 25-YR.POND C OUTFLOW 2.135 1460 265,015 39.36 11 100-YR.POND C OUTFLOW 2.385 1460 307,341 39.36 12 2-YR.ORIFICE DISCH.TO POND B FROM POND C 0.468 1020 28,488 0.00 13 10-YR. ORIFICE DISCH.TO POND B FROM POND C 0.855 1450 74,665 0.00 14 100-YR.ORIFICE DISCH.TO POND B FROM POND C 1.021 1460 102,500 0.00 15 SPLIT L-POOL DIFFERENCE 0.869 1020 108,664 0.00 16 SPLIT L-POOL DIFFERENCE 1.018 1450 149,099 0.00 17 SPLIT L-POOL DIFFERENCE 1.114 1460 162,516 0.00 18 2-YR.POND B OUTFLOW 0.334 1590 28,488 0.00 19 10-YR.POND B OUTFLOW 0.550 1950 65,560 0.00 20 100-YR.POND B OUTFLOW 0.654 2130 79,675 0.00 21 OFF-SITE BYPASS AREA 0.140 480 3,939 0.95 22 BASIN#1 - 100-YR.DEVELOPED FLOW 27.484 480 445,832 50.16 23 BASIN#1 -BYPASS AREA 100 YR.FLOW 0.713 480 17,829 4.30 24 BASIN#1 -OFF-SITE TRIB.AREA 100 YR.FLOW 0.499 480 12,480 3.01 WATER WORKS OUTPUT FOR CEDAR CREST-Page 4 Phases 3&4 STAGE STORAGE TABLE CUSTOM STORAGE ID No.PONDB Description:POND B W/30%F.S. STORAGE STORAGE STAGE CF] Ac-FT] FT] 240.00 0 0.0000 240.50 2159 0.0496 241.00 4318 0.0991 241.50 6477 0.1487 242.00 8635 0.1982 242.50 11925 0.2738 243.00 15215 0.3493 243.50 18505 0.4248 244.00 21794 0.5003 244.50 26439 0.6069 245.00 31083 0.7136 245.50 35727 0.8202 246.00 40371 0.9268 246.50 46575 1.0692 247.00 52779 1.2116 STAGE STORAGE TABLE CUSTOM STORAGE ID No.PONDC Description:POND C W/30%F.S. STAGE STORAGE STORAGE FT] CF] Ac-FT] 243.60 0 0.0000 244.00 3968 0.0911 244.50 9685 0.2223 245.00 15402 0.3536 245.50 21119 0.4848 246.00 26835 0.6160 246.50 37135 0.8525 247.00 51409 1.1802 247.50 66677 1.5307 248.00 81945 1.8812 248.50 98996 2.2726 249.00 116047 2.6641 249.50 135503 3.1107 250.00 154959 3.5574 250.50 174414 4.0040 251.00 193870 4.4506 WATER WORKS OUTPUT FOR CEDAR CREST-Page 5 Phases 3&4 STAGE DISCHARGE TABLE RISER DISCHARGE ID No.BOVR Description:POND B OVERFLOW WEIR Riser Diameter(in): 24.00 elev: 246.50 ft Weir Coefficient...: 3.782 height: 247.00 ft Orif Coefficient...: 9.739 increm: 0.10 ft STAGE DISCHARGE FT] CFS] 246.50 0.0000 246.60 0.6159 246.70 1.7422 246.80 3.2006 246.90 4.9276 247.00 6.8865 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No.COMB2 Description:POND C DISCHARGE STRUCTURES Structure:ORIFI Structure: Structure:PONDC Structure: Structure:WEIR STAGE DISCHARGE FT] CFS] 243.60 0.5983 244.00 0.6278 244.50 0.6659 245.00 0.7039 245.50 0.7438 246.00 0.7836 246.50 1.0706 247.00 1.3265 247.50 1.5120 248.00 1.6699 248.50 1.8136 249.00 1.9466 249.50 2.0732 250.00 2.1938 250.50 2.3096 251.00 3.0373 WATER WORKS OUTPUT FOR CEDAR CREST-Page 6 Phases 3 &4 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No.COMB3 Description:POND B INFILTRATION&OVERFLOW Structure:PONDB Structure: Structure:BOVR Structure: Structure: STAGE DISCHARGE FT] CFS] 240.00 0.1991 240.50 0.2283 241.00 0.2575 241.50 0.2902 242.00 0.3228 242.50 0.3589 243.00 0.3949 243.50 0.4345 244.00 0.4740 244.50 0.5170 245.00 0.5599 245.50 0.6063 246.00 0.6527 246.50 0.7025 247.00 7.6388 STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No.ORIFI Description:DISCHARGE ORIFICE TO POND B Outlet Elev: 246.30 Elev: 245.30 ft Orifice Diameter: 4.5000 in. STAGE DISCHARGE FT] CFS] 246.30 0.0000 246.50 0.2458 247.00 0.4598 247.50 0.6020 248.00 0.7165 248.50 0.8151 249.00 0.9030 249.50 0.9830 250.00 1.0570 250.50 1.1262 251.00 1.1913 WATER WORKS OUTPUT FOR CEDAR CREST-Page 7 Phases 3 &4 STAGE DISCHARGE TABLE DISCHARGE LIST ID No.PONDB Description: INFILTRATION OF POND B STAGE DISCHARGE FT] CFS] 240.00 0.1991 240.50 0.2283 241.00 0.2575 241.50 0.2902 242.00 0.3228 242.50 0.3589 243.00 0.3949 243.50 0.4345 244.00 0.4740 244.50 0.5170 245.00 0.5599 245.50 0.6063 246.00 0.6527 246.50 0.7025 247.00 0.7523 STAGE DISCHARGE TABLE DISCHARGE LIST ID No.PONDC Description: INFILTRATION OF POND C STAGE DISCHARGE FT] CFS] 243.60 0.5983 244.00 0.6278 244.50 0.6659 245.00 0.7039 245.50 0.7438 246.00 0.7836 246.50 0.8249 247.00 0.8667 247.50 0.9101 248.00 0.9534 248.50 0.9985 249.00 1.0436 249.50 1.0902 250.00 1.1368 250.50 1.1834 251.00 1.2300 WATER WORKS OUTPUT FOR CEDAR CREST-Page 8 Phases 3&4 LEVEL POOL TABLE SUMMARY Description Inflow Storage Discharge P. Stage Volume Outflow P.Time CFS] ID ID FT]CF] [CFS] [Min] 2-YR POND C 7.28 PONDC COMB2 247.02 52161 1.336 1020 10-YR POND C 11.56 PONDC COMB2 248.72 106535 1.873 1450 25-YR POND C 14.54 PONDC COMB2 249.76 145439 2.135 1460 100-YR POND C 17.71 PONDC COMB2 250.84 187512 2.385 1460 2-YEAR POND B 0.47 PONDB COMB3 242.15 9653 0.334 1590 10-YEAR POND B 0.86 PONDB COMB3 244.88 29961 0.550 1950 100-YEAR POND B 1.02 PONDB COMB3 246.02 40569 0.654 2130 WATER WORKS OUTPUT FOR CEDAR CREST—Page 9 Phases 3 & 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Is" Peak Rainfall Intensity The peak rainfall intensity (1,) for the specified return frequency (a) design storm Is determined using a unit peak rainfall intensity factor (iR) for a given return frequency (,) design storm using the following equation: IR = (PR)(1R) where: PR is the total precipitation at the project site for the 24-hour duration design storm event for the given return frequency (from the Isopluvial Maps in Figures 3.5.1C through 3.5.1H) iR aR)(TJ roR' ; the unit peak rainfall intensity factor Where T, time of concentration (minutes), calculated using the method described below only (T, minimum value is 6.3 minutes) aR and bR are coefficients (from Table 4.3.3B) used to adjust the equation for the design storm return frequency (A) This "iR" equation was developed by SWM Division staff from equations originally developed by Ron Mayo, P.E.. It is based on the original Renton/Seattle Intensity/Duration/Frequency (I.D.F.) curves. Rather than requiring a family of curves for various locations in King County this equation adjusts proportionally the Renton/Seattle I.D.F. curve data by using the 24-hour duration total precipitation isopluvial maps. This adjustment is based on the assumption that the localized geo-climatic conditions that control the total volume of precipitation at a specific location also control the peak intensities proportionally. Figure 4.3.3A has been included to demonstrate that this unit peak rainfall intensity (iR) will generate a curve with the same characteristics as the historic 25 year I.D.F. curve. Note, T, must not be less than 6.3 minutes or greater than 100 minutes. On the historic I.D.F. curves the lower limit was set at 5 minutes, 6.3 minutes was selected based on the mathematical limits of the equation coefficients. TABLE 4.3.3B COEFFICIENTS FOR THE RATIONAL METHOD "is" -EQUATION DESIGN STORM RETURN FREQUENCY (YEARS) aR bR 2 Year 1.58 0.58 5 Year 2.33 0.63 10 Year 2.44 0.64 25 Year 2.66 0.65 50 Year 2.75 0.65 100 Year 2.61 0.63 4.3.3-3 1/90 TABLE OF FLOWS USED FOR HYDRAULIC GRADE LINE CALCULATIONS FOR EACH CATCHMENT AREA BASIN 2 SBUH FLOWS: Q(25)=13.63 Q(100)=16.36 TOTAL TRIBUTARY AREA(AC.): 32.43 LINE AREA OF TOTAL AREA 0(25) 0(100) 1 0.31 0.96% 0.13 0.16 2 0.02 0.06% 0.01 0.01 3 0.19 0.59% 0.08 0.10 4 0.92 2.84% 0.39 0.46 5 0.89 2.74% 0.37 0.45 6 0.90 2.78% 0.38 0.45 7 0.51 1.57% 0.21 0.26 8 0.00 0.00% 0.00 0.00 9 0.28 0.86% 0.12 0.14 10 0.46 1.42% 0.19 0.23 11 1.01 3.11% 0.42 0.51 12 0.65 2.00% 0.27 0.33 13 2.05 6.32% 0.86 1.03 14 1.01 3.11% 0.42 0.51 15 0.44 1.36% 0.18 0.22 16 0.53 1.63% 0.22 0.27 17 1.08 3.33% 0.45 0.54 18 0.66 2.04% 0.28 0.33 19 0.12 0.37% 0.05 0.06 20 0.58 1.79% 0.24 0.29 21 0.51 1.57% 0.21 0.26 22 0.66 2.04% 0.28 0.33 23 0.71 2.19% 0.30 0.36 24 0.58 1.79% 0.24 0.29 25 0.32 0.99% 0.13 0.16 26 0.00 0.00% 0.00 0.00 27 0.02 0.06% 0.01 0.01 28 0.35 1.08% 0.15 0.18 29 0.89 2.74% 0.37 0.45 30 1.18 3.64% 0.50 0.60 31 1.02 3.15% 0.43 0.51 32 0.74 2.28% 0.31 0.37 33 0.39 1.20% 0.16 0.20 34 0.23 0.71% 0.10 0.12 35 0.25 0.77% 0.11 0.13 36 0.20 0.62% 0.08 0.10 37 0.37 1.14% 0.16 0.19 38 0.40 1.23% 0.17 0.20 39 0.57 1.76% 0.24 0.29 40 0.43 1.33% 0.18 0.22 41 0.62 1.91% 0.26 0.31 42 0.28 0.86% 0.12 0.14 43 0.17 0.52% 0.07 0.09 44 0.38 1.17% 0.16 0.19 45 1.02 3.15% 0.43 0.51 46 0.29 0.89% 0.12 0.15 47 0.30 0.93% 0.13 0.15 48 0.95 2.93% 0.40 0.48 49 0.73 2.25% 0.31 0.37 50 0.61 1.88% 0.26 0.31 51 0.30 0.93% 0.13 0.15 52 0.51 1.57% 0.21 0.26 53 0.31 0.96% 0.13 0.16 54 0.61 1.88% 0.26 0.31 55 0.84 2.59% 0.35 0.42 56 0.30 0.93% 0.13 0.15 57 1.78 5.49% 0.75 0.90 SUM TOTALS: 100.000% 13.63 16.36 STORM DRAINAGE REPORT FOR CEDAR CREST Phases 3 and 4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 25 YR. FILE: BASIN225.STM RAINFALL FILE: 25 YEAR DESIGN STORM i = 0.000/ ( Tc + 0.000) " 0.0 LINEN DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINEN TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOW' lac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 1 CB 3-1 0.3 0.58 5.00 0.00 0.00 0.13 36D 244.26 51 0.012 0.000 249.76 2.23 DNLN = 0 31.4 0.58 17.04 0.00 0.00 15.77 51.6 36D 244.00 0.005 1.25 249.76 2.23 2 CB 3-2 0.0 0.58 5.00 0.00 0.00 0.01 36D 244.68 84 0.012 0.000 249.86 2.21 DNLN = 1 31.1 0.58 16.40 0.00 0.00 15.64 51.1 36D 244.26 0.005 1.24 249.86 2.21 3 CB 3-3 0.2 0.58 5.00 0.00 0.00 0.08 36D 244.88 39 0.012 0.000 249.95 2.21 DNLN = 2 31.1 0.58 16.11 0.00 0.00 15.63 51.7 36D 244.68 0.005 1.25 249.95 2.21 4 CB 3-4 0.9 0.58 5.00 0.00 0.00 0.39 15D 250.34 84 0.012 0.017 251.47 6.87 DNLN = 3 14.0 0.58 13.07 0.00 0.00 8.00 15.2 15D 246.38 0.047 1.25 250.05 6.52 5 CB 3-6 0.9 0.58 5.00 0.00 0.00 0.37 15D 251.86 152 0.012 0.004 252.97 6.62 DNLN = 4 13.0 0.58 12.67 0.00 0.00 7.61 7.0 15D 250.34 0.010 1.25 252.38 6.2C 6 CB 3-8 0.9 0.58 5.00 0.00 0.00 0.38 15D 253.36 150 0.012 0.004 254.45 6.4C DNLN = 5 12.1 0.58 12.27 0.00 0.00 7.24 7.0 15D 251.86 0.010 1.25 253.82 5.9C 7 CB 3-10 0.5 0.58 5.00 0.00 0.00 0.21 15D 255.50 183 0.012 0.007 256.55 6.24 DNLN = 6 11.2 0.58 11.75 0.00 0.00 6.86 7.6 15D 253.36 0.012 1.25 255.24 5.5' 8 CB 3-12 0.0 0.58 5.00 0.00 0.00 0.00 15D 256.54 70 0.012 0.004 257.57 6.14 DNLN = 7 10.7 0.58 11.55 0.00 0.00 6.65 8.5 15D 255.50 0.015 1.25 257.30 5.4:. 9 CB 3-14 0.3 0.58 5.00 0.00 0.00 0.12 15D 257.81 127 0.012 0.004 258.83 6.0': DNLN = 8 10.3 0.58 11.18 0.00 0.00 6.47 7.0 15D 256.54 0.010 1.25 258.30 5.2' 10 CB 3-15 0.5 0.58 5.00 0.00 0.00 0.19 15D 258.09 28 0.012 0.000 259.54 5.1' DNLN = 9 10.0 0.58 11.09 0.00 0.00 6.35 7.0 15D 257.81 0.010 1.25 259.54 5.1 11 CB 3-16 1.0 0.58 5.00 0.00 0.00 0.42 12D 260.45 139 0.012 0.010 261.41 7.94 DNLN = 10 9.6 0.58 10.79 0.00 0.00 6.16 5.0 12D 258.09 0.017 1.25 260.06 7.84 12 CB 3-17 0.6 0.58 5.00 0.00 0.00 0.27 12D 270.50 241 0.012 0.036 271.32 5.4( DNLN = 11 3.7 0.58 6.57 0.00 0.00 3.71 7.7 12D 260.95 0.040 1.25 262.64 4.7:. 13 CB 3-18 2.0 0.58 5.00 0.00 0.00 3.02 12D 278.81 200 0.012 0.041 280.01 4.8' DNLN = 12 2.0 0.58 5.00 0.00 0.00 3.02 7.9 12D 270.50 0.042 1.25 271.88 3.8' 14 CB 3-20 1.0 0.58 5.00 0.00 0.00 0.42 12D 271.03 53 0.012 0.000 271.89 0.5 DNLN = 12 1.0 0.58 5.00 0.00 0.00 0.42 3.9 12D 270.50 0.010 1.25 271.88 0.5 15 CB 3-13 0.4 0.58 5.00 0.00 0.00 0.18 8D 257.99 31 0.012 0.000 258.31 1.2. DNLN = 8 0.4 0.58 5.00 0.00 0.00 0.18 1.9 8D 257.37 0.020 1.25 258.30 0.5. 16 CB 3-22 0.5 0.58 5.00 0.00 0.00 0.22 12D 261.57 62 0.012 0.000 262.64 2.5 DNLN = 11 4.9 0.58 10.39 0.00 0.00 2.03 3.9 12D 260.95 0.010 1.25 262.64 2.5 17 CB 3-24 1.1 0.58 5.00 0.00 0.00 0.45 12D 263.88 106 0.012 0.016 264.45 3.9 DNLN = 16 4.3 0.58 9.82 0.00 0.00 1.81 5.7 12D 261.57 0.022 1.25 262.77 2.3 18 CB 3-26 0.7 0.58 5.00 0.00 0.00 0.28 12D 269.68 203 0.012 0.027 270.17 3.5 DNLN = 17 3.2 0.58 8.57 0.00 0.00 1.36 6.5 12D 263.88 0.029 1.25 264.75 1.8 19 CB 3-28 0.1 0.58 5.00 0.00 0.00 0.05 12D 273.30 127 0.012 0.026 273.74 3.2 DNLN = 18 2.6 0.58 7.72 0.00 0.00 1.08 6.5 12D 269.68 0.029 1.25 270.41 1.7 20 CB 3-29 0.6 0.58 5.00 0.00 0.00 0.24 12D 274.17 38 0.012 0.017 274.60 3.1. DNLN = 19 2.5 0.58 7.47 0.00 0.00 1.03 5.8 12D 273.30 0.023 1.25 273.94 1.9 21 CB 3-30 0.5 0.58 5.00 0.00 0.00 0.21 12D 276.28 56 0.012 0.033 276.66 2.9 DNLN = 20 1.9 0.58 7.05 0.00 0.00 0.79 7.5 12D 274.17 0.038 1.25 274.80 1.5 22 CB 3-32 0.7 0.58 5.00 0.00 0.00 0.28 12D 279.25 133 0.012 0.021 279.57 2.6 DNLN = 21 1.4 0.58 5.94 0.00 0.00 0.58 5.8 12D 276.28 0.022 1.25 276.82 1.3 23 CB 3-34 0.7 0.58 5.00 0.00 0.00 0.30 12D 281.69 85 0.012 0.027 282.01 2.1 DNLN = 22 0.7 0.58 5.00 0.00 0.00 0.30 6.5 12D 279.25 0.029 1.25 279.71 0.8 24 CB 3-35 0.6 0.58 5.00 0.00 0.00 0.24 24D 246.02 128 0.012 0.000 250.05 2.4 DNLN = 3 16.9 0.58 15.22 0.00 0.00 7.55 17.3 24D 245.38 0.005 1.25 250.05 2.4 25 CB 3-36 0.3 0.58 5.00 0.00 0.00 0.13 24D 246.66 28 0.012 0.000 250.16 2.2 DNLN = 24 16.4 0.58 15.02 0.00 0.00 7.31 17.3 24D 246.52 0.005 1.25 250.16 2.2 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 25 YR. FILE: BASIN225.STM AINFALL FILE: 25 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.0(. LINE* DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE* TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOWN lac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/sl 26 CB 3-37 0.0 0.58 5.00 0.00 0.00 0.00 24D 246.92 51 0.012 0.000 250.26 2.29 DNLN = 25 16.0 0.58 14.65 0.00 0.00 7.18 17.5 24D 246.66 0.005 1.25 250.26 2.29 27 CB 3-38 0.0 0.58 5.00 0.00 0.00 0.01 24D 247.16 47 0.012 0.000 250.36 2.29 DNLN = 26 16.0 0.58 14.31 0.00 0.00 7.18 17.5 24D 246.92 0.005 1.25 250.36 2.29 28 CB 3-39 0.3 0.58 5.00 0.00 0.00 0.15 24D 247.30 28 0.012 0.000 250.47 2.28 DNLN = 27 16.0 0.58 14.10 0.00 0.00 7.17 17.3 24D 247.16 0.005 1.25 250.47 2.28 29 CB 3-40 0.9 0.58 5.00 0.00 0.00 0.37 18D 249.14 77 0.012 0.000 250.55 4.07 DNLN = 28 15.7 0.58 13.78 0.00 0.00 7.02 17.2 18D 247.38 0.023 1.25 250.57 3.97 30 CB 3-42 1.2 0.58 5.00 0.00 0.00 0.50 18D 252.07 201 0.012 0.011 253.05 5.41 DNLN = 29 14.8 0.58 13.05 0.00 0.00 6.65 13.7 18D 249.14 0.015 1.25 250.87 3.76 31 CB 3-44 1.0 0.58 5.00 0.00 0.00 0.43 12D 255.01 200 0.012 0.012 255.97 7.93 DNLN = 30 13.6 0.58 12.63 0.00 0.00 6.15 4.7 12D 252.07 0.015 1.25 253.62 7.83 32 CB 3-47 0.7 0.58 5.00 0.00 0.00 0.31 12D 257.95 204 0.012 0.008 258.90 7.41 DNLN = 31 12.6 0.58 12.17 0.00 0.00 5.72 4.6 12D 255.01 0.014 1.25 257.19 7.2E 33 CB 3-49 0.4 0.58 5.00 0.00 0.00 0.16 12D 259.98 118 0.012 0.008 260.92 7.06 DNLN = 32 11.8 0.58 11.89 0.00 0.00 5.41 5.1 12D 257.95 0.017 1.25 259.97 6.89 34 CB 3-50 0.2 0.58 5.00 0.00 0.00 0.10 12D 261.46 75 0.012 0.007 262.39 6.88 DNLN = 33 11.5 0.58 11.70 0.00 0.00 5.25 5.4 12D 259.98 0.020 1.25 261.89 6.68 35 CB 3-52 0.2 0.58 5.00 0.00 0.00 0.11 12D 261.98 52 0.012 0.000 263.31 6.56 DNLN = 34 11.2 0.58 11.57 0.00 0.00 5.15 3.9 12D 261.46 0.010 1.25 263.31 6.56 36 CB 4-1 0.2 0.58 5.00 0.00 0.00 0.08 120 262.52 54 0.012 0.000 264.15 6.42 DNLN = 35 11.0 0.58 11.43 0.00 0.00 5.04 3.9 12D 261.98 0.010 1.25 264.15 6.42 37 CB 4-2 0.4 0.58 5.00 0.00 0.00 0.16 12D 263.28 76 0.012 0.000 264.95 6.32 DNLN = 36 10.8 0.58 11.23 0.00 0.00 4.96 3.9 12D 262.52 0.010 1.25 264.95 6.32 38 CB 4-3 0.4 0.58 5.00 0.00 0.00 0.17 12D 268.25 98 0.012 0.032 268.83 3.97 DNLN = 37 4.5 0.58 9.22 0.00 0.00 1.88 8.2 12D 263.78 0.046 1.25 265.72 2.39 39 CB 4-4 0.6 .0.58 5.00 0.00 0.00 0.24 12D 269.95 87 0.012 0.016 270.50 3.83 DNLN = 38 4.1 0.58 8.74 0.00 0.00 1.71 5.4 12D 268.25 0.020 1.25 269.14 2.32 40 CB 4-5 0.4 0.58 5.00 0.00 0.00 0.18 12D 275.73 162 0.012 0.033 276.11 2.92 DNLN = 39 1.9 0.58 7.41 0.00 0.00 0.79 7.3 12D 269.95 0.036 1.25 270.79 1.12 41 CB 4-7 0.6 0.58 5.00 0.00 0.00 0.26 12D 277.23 54 0.012 0.024 277.56 2.69 DNLN = 40 1.5 0.58 6.97 0.00 0.00 0.61 6.4 12D 275.73 0.028 1.25 276.27 1.4C 42 CB 4-8 0.3 0.58 5.00 0.00 0.00 0.12 12D 278.73 57 0.012 0.022 278.98 2.27 DNLN = 41 0.8 0.58 6.38 0.00 0.00 0.35 6.3 12D 277.23 0.026 1.25 277.70 0.9E 43 CB 4-9 0.2 0.58 5.00 0.00 0.00 0.07 12D 279.03 30 0.012 0.005 279.23 2.01 DNLN = 42 0.6 0.58 6.04 0.00 0.00 0.23 3.9 12D 278.73 0.010 1.25 279.08 0.94 44 CB 4-10 0.4 0.58 5.00 0.00 0.00 0.16 12D 281.21 84 0.012 0.025 281.44 1.81 DNLN = 43 0.4 0.58 5.00 0.00 0.00 0.16 6.2 12D 279.03 0.026 1.25 279.31 0.8E 45 CB 4-11 1.0 0.58 5.00 0.00 0.00 0.43 12D 270.64 69 0.012 0.003 270.99 2.7E DNLN = 39 1.6 0.58 7.57 0.00 0.00 0.68 3.9 12D 269.95 0.010 1.25 270.79 0.9" 46 CB 4-13 0.3 0.58 5.00 0.00 0.00 0.12 12D 272.47 122 0.012 0.013 272.68 2.0E DNLN = 45 0.6 0.58 6.06 0.00 0.00 0.25 4.7 12D 270.64 0.015 1.25 271.14 0.64 47 CB 4-14 0.3 0.58 5.00 0.00 0.00 0.13 12D 273.84 76 0.012 0.017 274.05 1.7 DNLN = 46 0.3 0.58 5.00 0.00 0.00 0.13 5.2 12D 272.47 0.018 1.25 272.76 0.6" 48 CB 4-16 0.9 0.58 5.00 0.00 0.00 0.40 12D 264.35 82 0.012 0.000 265.72 3.7: DNLN = 37 5.9 0.58 10.86 0.00 0.00 2.92 3.9 12D 263.53 0.010 1.25 265.72 3.7: 49 CB 4-18 0.7 0.58 5.00 0.00 0.00 0.31 12D 266.17 182 0.012 0.005 266.84 4.41 DNLN = 48 5.0 0.58 10.07 0.00 0.00 2.52 3.9 12D 264.35 0.010 1.25 265.99 3.2 50 CB 4-20 0.6 0.58 5.00 0.00 0.00 0.26 12D 267.32 115 0.012 0.006 267.95 4.2 DNLN = 49 4.3 0.58 9.53 0.00 0.00 2.21 3.9 12D 266.17 0.010 1.25 267.23 2.8 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 25 YR. FILE: BASIN225.STM RAINFALL FILE: 25 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) ^ 0.' LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/Doi ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) )ft/ 51 CB 4-21 0.3 0.58 5.00 0.00 0.00 0.13 12D 268.15 58 0.012 0.008 268.74 4.0 DNLN = 50 3.7 0.58 9.26 0.00 0.00 1.95 3.9 12D 267.57 0.010 1.25 268.30 3.1 52 CB 4-22 0.5 0.58 5.00 0.00 0.00 0.21 12D 268.43 28 0.012 -0.002 269.00 3.9 DNLN = 51 3.4 0.58 9.11 0.00 0.00 1.82 3.9 12D 268.15 0.010 1.25 269.06 2.4 53 CB 4-23 0.3 0.58 5.00 0.00 0.00 0.13 12D 269.14 71 0.012 0.005 269.68 3.7 DNLN = 52 2.8 0.58 8.72 0.00 0.00 1.61 3.9 12D 268.43 0.010 1.25 269.30 2.2 54 CB 4-24 0.6 0.58 5.00 0.00 0.00 0.26 12D 272.17 103 0.012 0.027 272.69 3.6 DNLN = 53 2.5 0.58 8.12 0.00 0.00 1.48 6.6 12D 269.14 0.029 1.25 269.95 2.1 55 CB 4-26 0.8 0.58 5.00 0.00 0.00 0.35 12D 278.25 200 0.012 0.029 278.72 3.3 DNLN = 54 1.9 0.58 6.86 0.00 0.00 1.22 6.7 12D 272.17 0.030 1.25 272.94 1.8 56 CB 4-28 0.3 0.58 5.00 0.00 0.00 0.13 12D 282.80 150 0.012 0.028 283.20 3.0 DNLN = 55 1.1 0.58 5.75 0.00 0.00 0.87 6.7 12D 278.25 0.030 1.25 278.94 1.5 57 CB 4-29 0.8 0.58 5.00 0.00 0.00 0.74 12D 285.84 100 0.012 0.030 286.36 2.8 DNLN = 56 0.8 0.58 5.00 0.00 0.00 0.74 6.7 12D 282.80 0.030 1.25 283.37 1.r, HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 100 YR. FILE: BASIN210.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.0 LINE() DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE() TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOT., ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 1 CB 3-1 0.3 0.58 5.00 0.00 0.00 0.16 36D 244.26 51 0.012 0.000 250.80 2.6' DNLN = 0 31.4 0.58 15.69 0.00 0.00 18.88 51.6 36D 244.00 0.005 1.25 250.80 2.6"' 2 CB 3-2 0.0 0.58 5.00 0.00 0.00 0.01 36D 244.68 84 0.012 0.000 250.94 2.6` DNLN = 1 31.1 0.58 15.17 0.00 0.00 18.72 51.1 36D 244.26 0.005 1.24 250.94 2.6` 3 CE 3-3 0.2 0.58 5.00 0.00 0.00 0.10 36D 244.88 39 0.012 0.000 251.07 2.6' DNLN = 2 31.1 0.58 14.92 0.00 0.00 18.71 51.7 36D 244.68 0.005 1.25 251.07 2.6'. 4 CB 3-4 0.9 0.58 5.00 0.00 0.00 0.46 15D 250.34 84 0.012 0.004 251.52 7.9' DNLN = 3 14.0 0.58 12.31 0.00 0.00 9.55 15.2 15D 246.38 0.047 1.25 251.21 7.71 5 CB 3-6 0.9 0.58 5.00 0.00 0.00 0.45 15D 251.86 152 0.012 0.002 253.03 7.6. DNLN = 4 13.0 0.58 11.98 0.00 0.00 9.09 7.0 15D 250.34 0.010 1.25 252.75 7.41 6 CB 3-8 0.9 0.58 5.00 0.00 0.00 0.45 15D 253.36 150 0.012 0.002 254.51 7.3'; DNLN = 5 12.1 0.58 11.63 0.00 0.00 8.64 7.0 15D 251.86 0.010 1.25 254.16 7.0 7 CB 3-10 0.5 0.58 5.00 0.00 0.00 0.26 15D 255.50 183 0.012 0.006 256.63 7.0 DNLN = 6 11.2 0.58 11.18 0.00 0.00 8.19 7.6 15D 253.36 0.012 1.25 255.55 6.6 8 CB 3-12 0.0 0.58 5.00 0.00 0.00 0.00 15D 256.54 70 0.012 0.001 257.67 6.8 DNLN = 7 10.7 0.58 11.01 0.00 0.00 7.93 8.5 15D 255.50 0.015 1.25 257.58 6.4' 9 CB 3-14 0.3 0.58 5.00 0.00 0.00 0.14 15D 257.81 127 0.012 0.003 258.92 6.7 DNLN = 8 10.3 0.58 10.68 0.00 0.00 7.71 7.0 15D 256.54 0.010 1.25 258.57 6.2 10 CB 3-15 0.5 0.58 5.00 0.00 0.00 0.23 15D 258.09 28 0.012 0.000 259.79 6.1 DNLN = 9 10.0 0.58 10.60 0.00 0.00 7.57 7.0 15D 257.81 0.010 1.25 259.79 6.1 11 CB 3-16 1.0 0.58 5.00 0.00 0.00 0.51 12D 260.45 139 0.012 0.006 261.43 9.3 DNLN = 10 9.6 0.58 10.36 0.00 0.00 7.34 5.0 12D 258.09 0.017 1.25 260.53 9.3 12 CB 3-17 0.6 0.58 5.00 0.00 0.00 0.33 12D 270.50 241 0.012 0.034 271.39 5.9 DNLN = 11 3.7 0.58 6.36 0.00 0.00 4.39 7.7 12D 260.95 0.040 1.25 263.14 5.5' 13 CB 3-18 2.0 0.58 5.00 0.00 0.00 3.55 12D 278.81 200 0.012 0.040 280.15 5.2' DNLN = 12 2.0 0.58 5.00 0.00 0.00 3.55 7.9 12D 270.50 0.042 1.25 272.08 4.5. 14 CB 3-20 1.0 -0.58 5.00 0.00 0.00 0.51 12D 271.03 53 0.012 0.000 272.09 0.6 DNLN = 12 1.0 0.58 5.00 0.00 0.00 0.51 3.9 12D 270.50 0.010 1.25 272.08 0.6 15 CB 3-13 0.4 0.58 5.00 0.00 0.00 0.22 8D 257.99 31 0.012 0.000 258.57 0.6 DNLN = 8 0.4 0.58 5.00 0.00 0.00 0.22 1.9 8D 257.37 0.020 1.25 258.57 0.6 16 CB 3-22 0.5 0.58 5.00 0.00 0.00 0.27 12D 261.57 62 0.012 0.000 263.14 3.: DNLN = 11 4.9 0.58 10.02 0.00 0.00 2.44 3.9 12D 260.95 0.010 1.25 263.14 3.] 17 CB 3-24 1.1 0.58 5.00 0.00 0.00 0.54 12D 263.88 106 0.012 0.011 264.50 4.: DNLN = 16 4.3 0.58 9.52 0.00 0.00 2.17 5.7 12D 261.57 0.022 1.25 263.33 2.7 18 CB 3-26 0.7 0.58 5.00 0.00 0.00 0.33 12D 269.68 203 0.012 0.026 270.22 3.7 DNLN = 17 3.2 0.58 8.36 0.00 0.00 1.63 6.5 .12D 263.88 0.029 1.25 264.85 2.1 19 CB 3-28 0.1 0.58 5.00 0.00 0.00 0.06 12D 273.30 127 0.012 0.026 273.78 3.4 DNLN = 18 2.6 0.58 7.57 0.00 0.00 1.30 6.5 12D 269.68 0.029 1.25 270.50 1.9 20 CB 3-29 0.6 0.58 5.00 0.00 0.00 0.29 12D 274.17 38 0.012 0.016 274.64 3.4 DNLN = 19 2.5 0.58 7.34 0.00 0.00 1.24 5.8 12D 273.30 0.023 1.25 274.02 2.1 21 CB 3-30 0.5 0.58 5.00 0.00 0.00 0.26 12D 276.28 56 0.012 0.033 276.69 3.1 DNLN = 20 1.9 0.58 6.94 0.00 0.00 0.95 7.5 12D 274.17 0.038 1.25 274.87 1.6 22 CB 3-32 0.7 0.58 5.00 0.00 0.00 0.33 12D 279.25 133 0.012 0.020 279.60 2.- DNLN = 21 1.4 0.58 5.89 0.00 0.00 0.69 5.8 12D 276.28 0.022 1.25 276.88 1.4 23 CB 3-34 0.7 0.58 5.00 0.00 0.00 0.36 12D 281.69 85 0.012 0.027 282.05 2.! DNLN = 22 0.7 0.58 5.00 0.00 0.00 0.36 6.5 12D 279.25 0.029 1.25 279.75 0.' 24 CB 3-35 0.6 0.58 5.00 0.00 0.00 0.29 24D 246.02 128 0.012 0.000 251.21 2.1 DNLN = 3 16.9 0.58 14.18 0.00 0.00 9.06 17.3 24D 245.38 0.005 1.25 251.21 2.1 25 CB 3-36 0.3 0.58 5.00 0.00 0.00 0.16 24D 246.66 28 0.012 0.000 251.37 2. DNLN = 24 16.4 0.58 14.01 0.00 0.00 8.77 17.3 24D 246.52 0.005 1.25 251.37 2. HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3 &4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 100 YR. FILE: BASIN210.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.0 LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DO€ ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s 26 CB 3-37 0.0 0.58 5.00 0.00 0.00 0.00 24D 246.92 51 0.012 0.000 251.52 2.74 DNLN = 25 16.0 0.58 13.70 0.00 0.00 8.61 17.5 24D 246.66 0.005 1.25 251.52 2.74 27 CB 3-38 0.0 0.58 5.00 0.00 0.00 0.01 24D 247.16 47 0.012 0.000 251.67 2.74 DNLN = 26 16.0 0.58 13.42 0.00 0.00 8.61 17.5 24D 246.92 0.005 1.25 251.67 2.74 28 CB 3-39 0.3 0.58 5.00 0.00 0.00 0.18 24D 247.30 28 0.012 0.000 251.81 2.74 DNLN = 27 16.0 0.58 13.25 0.00 0.00 8%60 17.3 24D 247.16 0.005 1.25 251.81 2.74 29 CB 3-40 0.9 0.58 5.00 0.00 0.00 0.45 18D 249.14 77 0.012 0.000 251.96 4.7E DNLN = 28 15.7 0.58 12.98 0.00 0.00 8.42 17.2 18D 247.38 0.023 1.25 251.96 4.7( 30 CB 3-42 1.2 0.58 5.00 0.00 0.00 0.60 18D 252.07 201 0.012 0.004 253.15 5.8" DNLN = 29 14.8 0.58 12.33 0.00 0.00 7.97 13.7 18D 249.14 0.015 1.25 252.40 4.5: 31 CB 3-44 1.0 0.58 5.00 0.00 0.00 0.51 12D 255.01 200 0.012 0.011 255.99 9.4: DNLN = 30 13.6 0.58 11.98 0.00 0.00 7.37 4.7 12D 252.07 0.015 1.25 253.82 9.3f 32 CB 3-47 0.7 0.58 5.00 0.00 0.00 0.37 12D 257.95 204 0.012 0.006 258.93 8.7, DNLN = 31 12.6 0.58 11.59 0.00 0.00 6.86 4.6 12D 255.01 0.014 1.25 257.72 8.7: 33 CB 3-49 0.4 0.58 5.00 0.00 0.00 0.20 12D 259.98 118 0.012 0.004 260.95 8.3: DNLN = 32 11.8 0.58 11.35 0.00 0.00 6.49 5.1 12D 257.95 0.017 1.25 260.43 8.2( 34 CB 3-50 0.2 0.58 5.00 0.00 0.00 0.12 12D 261.46 75 0.012 0.002 262.43 8.0, DNLN = 33 11.5 0.58 11.20 0.00 0.00 6.29 5.4 12D 259.98 0.020 1.25 262.30 8.0. 35 CB 3-52 0.2 0.58 5.00 0.00 0.00 0.13 12D 261.98 52 0.012 0.000 263.70 7.8: DNLN = 34 11.2 0.58 11.09 0.00 0.00 6.17 3.9 12D 261.46 0.010 1.25 263.70 7.8, 36 CB 4-1 0.2 0.58 5.00 0.00 0.00 0.10 12D 262.52 54 0.012 0.000 264.90 7.6 , DNLN = 35 11.0 0.58 10.97 0.00 0.00 6.04 3.9 12D 261.98 0.010 1.25 264.90 7.6 , 37 CB 4-2 0.4 0.58 5.00 0.00 0.00 0.19 12D 263.28 76 0.012 0.000 266.04 7.5, DNLN = 36 10.8 0.58 10.80 0.00 0.00 5.94 3.9 12D 262.52 0.010 1.25 266.04 7.5, 38 CB 4-3 0.4 0.58 5.00 0.00 0.00 0.20 12D 268.25 98 0.012 0.018 268.89 4.2 DNLN = 37 4.5 0.58 8.96 0.00 0.00 2.25 8.2 12D 263.78 0.046 1.25 267.15 2.8 f 39 CB 4-4 0.6 0.58 5.00 0.00 0.00 0.29 12D 269.95 87 0.012 0.015 270.56 4.1 DNLN = 38 4.1 0.58 8.53 0.00 0.00 2.05 5.4 12D 268.25 0.020 1.25 269.24 2.6 40 CB 4-5 0.4 0.58 5.00 0.00 0.00 0.22 12D 275.73 162 0.012 0.032 276.14 3.1 DNLN = 39 1.9 0.58 7.29 0.00 0.00 0.95 7.3 12D 269.95 0.036 1.25 270.88 1.2 41 CB 4-7 0.6 0.58 5.00 0.00 0.00 0.31 12D 277.23 54 0.012 0.023 277.59 2.8 DNLN = 40 1.5 0.58 6.87 0.00 0.00 0.73 6.4 12D 275.73 0.028 1.25 276.33 1.4 42 CB 4-8 0.3 0.58 5.00 0.00 0.00 0.14 12D 278.73 57 0.012 0.022 279.00 2.4 DNLN = 41 0.8 0.58 6.32 0.00 0.00 0.42 6.3 12D 277.23 0.026 1.25 277.75 1.0 43 CB 4-9 0.2 0.58 5.00 0.00 0.00 0.09 12D 279.03 30 0.012 0.005 279.25 2.1 DNLN = 42 0.6 0.58 6.00 0.00 0.00 0.28 3.9 12D 278.73 0.010 1.25 279.12 1.0 44 CB 4-10 0.4 0.58 5.00 0.00 0.00 0.19 12D 281.21 84 0.012 0.025 281.47 1.9 DNLN = 43 0.4 0.58 5.00 0.00 0.00 0.19 6.2 12D 279.03 0.026 1.25 279.34 0.9: 45 CB 4-11 1.0 0.58 5.00 0.00 0.00 0.51 12D 270.64 69 0.012 0.002 271.02 2.91 DNLN = 39 1.6 0.58 7.46 0.00 0.00 0.81 3.9 12D 269.95 0.010 1.25 270.88 1.0' 46 CB 4-13 0.3 0.58 5.00 0.00 0.00 0.15 12D 272.47 122 0.012 0.012 272.70 2.1 DNLN = 45 0.6 0.58 6.03 0.00 0.00 0.30 4.7 12D 270.64 0.015 1.25 271.19 0.6 47 CB 4-14 0.3 0.58 5.00 0.00 0.00 0.15 12D 273.84 76 0.012 0.017 274.07 1.7 DNLN = 46 0.3 0.58 5.00 0.00 0.00 0.15 5.2 12D 272.47 0.018 1.25 272.79 0.6. 48 CB 4-16 0.9 0.58 5.00 0.00 0.00 0.48 12D 264.351. 82 0.012 0.000 267.15 4.4, DNLN = 37 5.9 0.58 10.50 0.00 0.00 3.50 3.9 12D 263.53 0.010 1.25 267.15 4.4 49 CB 4-18 0.7 0.58 5.00 0.00 0.00 0.37 12D 266.17 182 0.012 0.000 267.54 3.E DNLN = 48 5.0 0.58 9.71 0.00 0.00 3.02 3.9 12D 264.35 0.010 1.25 267.54 3.E 50 CB 4-20 0.6 0.58 5.00 0.00 0.00 0.31 12D 267.32 115 0.012 0.002 268.01 4.` DNLN = 49 4.3 0.58 9.22 0.00 0.00 2.65 3.9 12D 266.17 0.010 1.25 267.83 3.2 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/11/99 STORM SEWER SUMMARY REPORT CEDAR CREST - BASIN 2 - 100 YR. FILE: BASIN210.STM AINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ 1 Tc + 0.000) ,. 0.00 LINE* DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINE* TOT AR WEIGHTD Tc TOIL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOWN lac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/s) 51 CB 4-21 0.3 0.58 5.00 0.00 0.00 0.15 12D 268.15 58 0.012 0.007 268.80 4.34 DNLN = 50 3.7 0.58 8.97 0.00 0.00 2.34 3.9 12D 267.57 0.010 1.25 268.42 3.30 52 CB 4-22 0.5 0.56 5.00 0.00 0.00 0.26 12D 268.43 28 0.012 -0.004 269.06 4.18 DNLN = 51 3.4 0.58 8.84 0.00 0.00 2.19 3.9 12D 268.15 0.010 1.25 269.16 2.79 53 CB 4-23 0.3 0.58 5.00 0.00 0.00 0.16 12D 269.14 71 0.012 0.005 269.73 4.01 DNLN = 52 2.8 0.58 8.47 0.00 0.00 1.93 3.9 12D 268.43 0.010 1.25 269.40 2.48 54 CB 4-24 0.6 0.58 5.00 0.00 0.00 0.31 12D 272.17 103 0.012 0.026 272.73 3.88 DNLN = 53 2.5 0.58 7.92 0.00 0.00 1.77 6.6 12D 269.14 0.029 1.25 270.04 2.38 55 CB 4-26 0.8 0.58 5.00 0.00 0.00 0.42 12D 278.25 200 0.012 0.029 278.76 3.60 DNLN = 54 1.9 0.58 6.74 0.00 0.00 1.46 6.7 12D 272.17 0.030 1.25 273.03 2.04 56 CB 4-28 0.3 0.58 5.00 0.00 0.00 0.15 12D 282.80 150 0.012 0.028 283.23 3.20 DNLN = 55 1.1 0.58 5.70 0.00 0.00 1.04 6.7 12D 278.25 0.030 1.25 279.01 1.61 57 CB 4-29 0.8 0.58 5.00 0.00 0.00 0.89 12D 285.84 100 0.012 0.030 286.42 3.03 DNLN = 56 0.8 0.58 5.00 0.00 0.00 0.89 6.7 12D 282.80 0.030 1.25 283.43 1.71 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/10/99 STORM SEWER SUMMARY REPORT CEDAR CREST - EMERGENCY OVERFLOW PIPE FILE: 951230V4.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.L- LINEN DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GRD VEL DOWNLINEN TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DO.^ ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/e 1 CB 1 0.0 0.58 0.00 0.00 0.00 0.00 30D 220.16 157 0.012 0.004 222.45 10.1( DNLN = 0 0.0 0.00 3.64 0.00 0.00 47.57 26.5 30D 219.60 0.004 1.25 221.89 10.1f 2 CB 2 0.0 0.58 0.00 0.00 0.00 0.00 30D 221.04 186 0.012 0.000 224.43 9.6' DNLN = 1 0.0 0.00 3.32 0.00 0.00 47.57 30.6 30D 220.16 0.005 1.25 224.43 9.6 3 CB 3 0.0 0.58 0.00 0.00 0.00 0.00 30D 223.57 202 0.012 0.000 226.25 9.6' DNLN = 2 0.0 0.00 2.97 0.00 0.00 47.57 49.7 30D 221.04 0.013 1.25 226.25 9.6' 4 CB 4 0.0 0.58 0.00 0.00 0.00 0.00 30D 229.39 85 0.012 0.042 231.68 10.1 DNLN = 3 0.0 0.00 2.83 0.00 0.00 47.57 99.6 30D 225.12 0.050 1.25 228.08 9.6' 5 CB 5 0.0 0.58 0.00 0.00 0.00 0.00 30D 235.10 368 0.012 0.008 236.60 6.5 DNLN = 4 0.0 0.00 1.67 0.00 0.00 20.09 52.6 30D 229.94 0.014 1.25 233.66 4.0 6 CB 6 0.0 0.58 0.00 0.00 0.00 0.64 24D 240.81 520 0.012 0.009 242.33 7.1 DNLN = 5 0.0 0.00 0.34 0.00 0.00 18.35 25.7 24D 235.10 0.011 1.25 237.43 5.8 7 CB 7 0.0 0.58 0.00 0.00 0.00 0.00 24D 241.93 100 0.012 0.001 243.42 7.0 DNLN = 6 0.0 0.00 0.08 0.00 0.00 17.71 25.9 24D 240.81 0.011 1.25 243.33 5.6 8 POND C OVERFLOW 0.0 0.58 0.00 0.00 0.00 17.71 24D 242.47 27 0.012 0.023 245.01 5.- DNLN = 7 0.0 0.00 0.00 0.00 0.00 17.71 34.7 24D 241.93 0.020 1.25 244.39 5.6 9 POND A OVERFLOW 0.0 0.58 0.00 0.00 0.00 27.48 24D 235.87 294 0.012 0.019 239.31 9.1 DNLN = 4 0.0 0.00 0.00 0.00 0.00 27.48 34.8 24D 229.94 0.020 1.25 233.66 8.- 10 POND B OVERFLOW 0.0 0.58 0.00 0.00 0.00 1.74 24D 238.99 168 0.012 0.006 239.66 3.5 DNLN = 5 0.0 0.00 0.00 0.00 0.00 1.74 17.3 24D 238.15 0.005 1.25 238.58 3.5 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 02/10/99 STORM SEWER SUMMARY REPORT CEDAR CREST - PIPE NETWORK FROM POND C TO POND B FILE: PONDC-B.STM RAINFALL FILE:100 YEAR DESIGN STORM I = 0.000/ ( Tc + 0.000) " 0.0( LINE# DESCRIPTION INC AR RUNOFFC INLTIME INLT I INC CIA INPUTQ UNIFORM SIZE/ INVERT PIPE NVAL HGLSLOPE HYD GAD VEL DOWNLINE# TOT AR WEIGHTD Tc TOTL I TOT CIA TOTALQ FLOWCAP TYPE UP/DOWN LEN INVSLOP JLC UP/DOWN UP/DOWr: ac) C (min) (in/h) (cfs) (cfs) (cfs) (in) (ft) (ft) (ft/ft) (ft/ft) (ft) (ft/si 1 CB 5-1 0.0 0.58 0.00 0.00 0.00 0.00 12D 240.38 76 0.012 0.005 240.80 3.22 DNLN = 0 0.0 0.00 3.23 0.00 0.00 1.02 2.7 12D 240.00 0.005 1.25 240.42 3.22 2 CB 5-2 0.0 0.58 0.00 0.00 0.00 0.00 12D 240.86 95 0.012 0.003 241.29 3.18 DNLN = 1 0.0 0.00 2.61 0.00 0.00 1.02 2.7 12D 240.38 0.005 1.25 241.01 1.98 3 CB 5-3 0.0 0.58 0.00 0.00 0.00 0.00 12D 241.92 211 0.012 0.004 242.35 3.18 DNLN = 2 0.0 0.00 1.25 0.00 0.00 1.02 2.7 12D 240.86 0.005 1.25 241.48 1.98 4 CB 5-4 0.0 0.58 0.00 0.00 0.00 0.00 12D 242.46 108 0.012 0.003 242.89 3.18 DNLN = 3 0.0 0.00 0.55 0.00 0.00 1.02 2.7 12D 241.92 0.005 1.25 242.54 1.98 5 CB 5-5 0.0 0.58 0.00 0.00 0.00 1.02 12D 246.30 85 0.012 0.045 246.92 3.18 DNLN = 4 0.0 0.00 0.00 0.00 0.00 1.02 8.2 12D 242.46 0.045 1.25 243.08 1.98 HYDRAULIC GRADE LINE CALCULATIONS FOR CEDAR CREST Phases 3&4 Geo 40 Engineers April 6, 1995 Geotechnical, Geoenvironmental and Geologic Services M.A. Segale, Inc. Manufactured/Modular Home Community Post Office Box 88050 Tukwila, Washington 98138 Attention: Mr. Dana Warren Report Addendum Hydrogeologic & Geotechnical Services Infiltration Ponds/Slope Stability Impacts Cedar Crest Manufactured Home Community Renton, Washington File No. 0291-006-T03 INTRODUCTION AND SCOPE This report addendum presents the results of our evaluation of potential slope stability impacts from the on-site'stormwater retention/infiltration system proposed for the Cedar Crest development. This addendum is a part of our Hydrogeologic & Geotechnical report for the project dated October 24, 1995. The proposed Cedar Crest manufactured home community will be situated within the Segale gravel mine site. The site consists of approximately 133 acres and is located north of the Maple Valley Road (State Route 169) and south of northeast 3rd Street in Renton, Washington. The site location is shown on the Site Plan/Vicinity Map, Figure 1. SITE CONDITIONS SURFACE CONDITIONS The site is located on the south margin of an upland area north of the Cedar River valley. The south margin of the site consists of a bluff that forms the north wall of the Cedar River valley. The site has been surface-mined for sand and gravel. Topography at the site generally consists of steep cut slopes along the north, east and west margins of the mine area and flat to gently rolling surfaces within the mine. The cut slopes at the margins of the surface-mine area generally range from 2H to 1V (50 percent) to 11 to 1 (75 percent). A natural slope extends down to the Cedar River valley on the south property margin. GeoEngineers,Inc. 6240 Tacoma Mall Blvd.,Suite 318 Tacoma,WA 98409 Telephone(206)471-0379 Fax(206)4710521 o„nmA no,nrvr!OA nano. M.A. Segale April 6, 1995 Page 2 The southern slopes are generally inclined at about 80 to 130 percent with localized near-vertical areas. The existing ground surface of the surface-mine area drains to the north-northwest. The extreme southern slope drains to the south. Construction of three retention ponds is proposed for on-site stormwater infiltration. The ponds will be located in the central portion of the development, at the base of the eastern and western pit walls as shown on Figure 1. There are no downward slopes in the vicinity of the ponds. SUBSURFACE CONDITIONS Geologic/soils conditions at the site are discussed in detail in our previous report. Soils at the site generally consist of fine to coarse-grained recessional and Vashon advance glacial outwash over older pre-Vashon glacial and inter-glacial deposits, and Tertiary bedrock (Eocene and/or Oligocene sedimentary rocks). Most of the recessional outwash has been removed from the pit area, exposing the advance outwash soils. The advance outwash generally consists of dense to very dense fine to medium sand with a variable gravel content and a trace of silt. Localized lenses of silty sand, sandy silt and clayey silt occur within the advance sediments. The Vashon advance sands typically have a moderate permeability. STORMWATER INFILTRATION The results of our previous study indicated that infiltration of storm water is feasible at the site and will, in effect, maintain the existing recharge of the ground water system. The granular soils in the site area are relatively permeable and we expect moderate to rapid downward percolation in the pond areas. Based on our previous study, the direction of ground water flow in the site area is west and northwest. Infiltration and dissipation rates for the soils in the proposed pond areas are discussed in our previous report. We understand that an infiltration blanket will be constructed north of the western pond to increase dissipation rates in accordance with our recommendations. The blanket will be constructed in the area shown on Figure 1. CONCLUSIONS AND RECOMMENDATIONS We conclude that infiltration of stormwater from the three proposed retention ponds will have no potential impact on slope stability at the site based on the following: Ground water flows to the west/northwest from the infiltration facilities. There are no downward slopes in the vicinity of the ponds; the pit walls adjacent to the ponds extend upward and will not be affected by the infiltration of stormwater. G e o E n g i nee r s File No.0291-006-T03 M.A. Segale April 6, 1995 Page 3 The southern slope extending downward from the site is at least 1000 feet south of the proposed retention ponds. The slope is upgradient from the ponds with respect to ground water flow and will not likely be impacted by the proposed infiltration. Ground water levels will be at or below historic levels in the slope areas. 1 O We appreciate the opportunity to work with you on this project. Please contact us if you have any questions. HE•Iv Yours very truly, o w ' • c11 ' GeoEn ineers, Inc.4 w o 4.7 012979 i'CISTF1 4)Gary W. Henderson SS'oNAL ECG Principal EXPIRES.5/o/46 SLF:GWH:vc Document ID:0291006R.ADD Five copies submitted G e o E n g i nee r s File No.0291-006-T03 1;1ATo ; Va Ala lug reeto 575-1(3 7 Hillside Fill Segale Business Park Cedar Crest Renton, Washington All fill placed on slopes should be placed in nearly level layers on benches, cut into the slope. Significant organics and unsuitable soil should be removed during or before benching. The width of individual benches should be sufficient to operate equipment and wide enough to result in a minimum 2 foot cut into native soil at the upslope edge of the bench. A schematic cross section of the benches is attached. All fill placed on slopes shall be uniformly compacted to at least 95 percent of its maximum dry density determined in accordance with ASTM D-1557 test procedures. Lift thickness should be selected to facilitate uniform compaction with the equipment used. Fill placement should proceed in a manner to prevent storm water runoff from flowing over and down the slope. Sloping each lift downward from the slope face inward will facilitate control of surface runoff. Slopes filling should be scheduled such that the completed slopes can be immediately seeded or else protected until vegetation can be established. Report Hydrogeologic & Geotechnical Services Proposed Residential Development Renton, Washington October 24, 1994 For M.A. Segale, Inc. Manufactured/Modular Home Community G e o E n g i n e e r s File No.0291-006-T03 Geo„Engineers October 24, 1994 Geotechnical, Geoenvironmental and Geologic Services M.A. Segale, Inc. Manufactured/Modular Home Community Post Office Box 88050 Tukwila, Washington 98138 Attention: Mr. Dana Warren Report Hydrogeologic & Geotechnical Services Cedar Crest Manufactured Home Community Renton, Washington File No. 0291-006-T03 INTRODUCTION This report presents the results of our geotechnical engineering services for your proposed Cedar Crest manufactured home community to be situated within the Segale gravel mine site. The site consists of approximately 133 acres and is located north of the Maple Valley Road(State Route 169) and south of northeast 3rd Street in Renton, Washington. The site location is shown on the Site Plan/Vicinity Map, Figure 1. Our understanding of the proposed project is based on discussions with you, our site visits and our review of the documents provided. We understand that the site will be developed as a MHC (manufactured home community) with approximately 400 manufactured homes. We also understand that streets and utilities, including sanitary sewer, will be constructed in accordance with the City of Renton design specifications. We understand that stormwater will be infiltrated on-site using roadway collection, treatment and infiltration systems. The proposed roadway, treatment and infiltration systems will be located within the transmission line right-of-way and in the east and west portions of the center of the site. For the purposes of clarity, the infiltration areas have been labeled A, B, and C on the attached site plan. We further understand that the grades in the proposed infiltration areas will be raised between 5 to 15 feet. GeoEngineers,Inc. 6240 Tacoma Mall Blvd.,Suite 318 Tacoma,WA 98409 Telephone(206)471-0379 Fax(206)471-0521 M.A. Segale, Inc. October 24, 1994 Page 2 SCOPE The purpose of our services is to evaluate the subsurface conditions at the site as a basis for developing geotechnical design criteria and recommendations for the proposed development of the site, including infiltration of the on-site storm water runoff. Specifically, our scope of services includes the following: 1. Review the available geologic and hydrologic data relevant to the site. 2. Conduct a geologic reconnaissance of the site area. 3. Evaluate the subsurface conditions at the site by monitoring the excavation of test pits. 4. Obtain soil samples at the proposed locations of the infiltration ponds, as appropriate. 5. Conduct laboratory tests on select soil samples with respect to storm water infiltration. 6. Provide our opinion with regard to the feasibility of infiltrating storm water runoff at the proposed locations. This will include infiltration rates for the soils, as appropriate. 7. Provide geotechnical recommendations for the proposed earthwork at the site. This will include criteria for structural fill and compaction, foundation design, cut and fill slopes, retaining and subgrade walls, utility trench backfill and roadway subgrade. DOCUMENT REVIEW In addition to the available soil, geologic and hydrologic data for the site area, we reviewed hydrologic-geotechnical information prepared by Golder Associates, Inc. (GAI). SITE CONDITIONS SURFACE CONDITIONS The site is located on the south margin of an upland area north of the Cedar River valley. The south margin of the site consists of a bluff that forms the north wall of the Cedar River valley. The site has been surface-mined for sand and gravel. Topography at the site generally consists of steep cut slopes along the north, east and west margins of the mine area and flat to gently rolling surfaces within the mine. The cut slopes at the margins of the surface-mine area generally range from 2H to 1 V (50 percent) to 11/ to 1 (75 percent). A natural slope extends down to the Cedar River valley on the south property margin. Slopes in this area are generally 80 to 130 percent with localized near-vertical areas. The existing ground surface of the surface-mine area drains to the north-northwest. The extreme southern slope drains to the south. Elevations in the upland area generally range from about 210 to 330 feet at the top of the bluff to between 230 and 300 feet in the central and north portions of the site. Vegetation at the site varies according to topography. The surface-mined upland areas are generally sparsely vegetated with grass, brush and occasional alder trees. Areas of denser vegetation consisting of heavy underbrush and scattered trees occur along the margins of the GeoEngineers File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 3 surface-mine area. Vegetation is well established along the south portion of the property, except for localized areas of steep slopes. Surface water was observed near the center of the site in storm water/silt control structures at the time of our site investigation. The water appears to be perched on a thin accumulation of fine soil. Flow from this area is to the west and north via an excavated ditch. The outflow is directed to a topographic basin located in the northwest portion of the site. Water seepage was observed in the topographic basin located in the northwest portion of the site. The water seepage appears to originate from a perched sandy silt lens within the hillside slope. The ground water seepage and surface water flow is collected in a drop-structure located near the center of the basin and discharged to the pond/drainage channel located in the northwest corner of the site. Based on our previous work at the site and our recent site reconnaissance, no significant ground water seepage was observed on the bluff face located at the south margin of the site. GEOLOGIC CONDITIONS General geologic conditions at the site were evaluated by reviewing published and nonpublished (in-house and outside reports) information, our geologic reconnaissance and excavating 21 test pits at the approximate locations shown on the site plan. Logs of our field explorations and laboratory results are presented in Figures 3 through 14. Subsurface conditions are described in detail in the Subsurface Conditions section of this report. The site is located on the southern margin of the Coalfield Drift Upland, a broad glacial outwash plain. Soils at the site generally consist of fine to coarse-grained recessional and advance glacial outwash over older pre-Vashon glacial and inter-glacial deposits, and Tertiary bedrock (Eocene and/or Oligocene sedimentary rocks). These deposits have been modified by weathering and erosion since the last glaciation and a surficial layer of topsoil has formed over the native soil deposits. The recessional outwash at the site is characterized as discontinuous layers of unconsolidated loose to medium dense sand and gravel deposited by meltwater from the retreating glacier(Vashon stade of the Fraser glaciation). Based on the geometry of the recessional deposits in the site area, the sands and gravel deposits in this area were likely deposited in/adjacent to a glacial outwash channel. Recessional deposits at the site contain only minor amounts of silt and have a moderate to high permeability. Within the pit, most of the recessional material has been removed. However, it remains in the pit walls and in areas adjacent to the pit. Glacial till, commonly referred to as "hard pan," consists of very dense silty sand with variable amounts of gravel, cobbles and boulders. The till is deposited at the base of the glacial ice as it over-rides the underlying sediments. Till typically has a low permeability. Glacial till is reported to occur along the east and west margins of the site and covers most of the upland G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 4 area to the north. It is likely that the outwash stream eroded or removed the Vashon till in the site area. Within the site area, Vashon advance outwash underlies the recessional deposits. The advance outwash generally consists of dense to very dense fine to medium sand with a variable gravel content and a trace of silt. Localized lenses of silty sand, sandy silt and clayey silt occur within the advance sediments. The Vashon advance sands typically have a moderate permeability. Variations in fines/gravel content and density may result in perched or concentrated ground water conditions. Glaciofluvial/interglacial silty sand, sandy silt and clayey silt underlies the Vashon advance sediments. These sediments were over-ridden by the glacier and are generally in a very dense condition. They typically have a low permeability. Older glacial sediments and Tertiary bedrock material are exposed along the lower elevations of the southern bluff, where the Cedar River bisected the upland area after the last glacial ice retreat from the area. Undifferentiated pre-Vashon glacial and interglacial deposits were observed along most of the southern bluff slope. These soils generally consist of older glacial outwash and till, and interbedded silt, silty sand and fine sand. These older soils are glacially consolidated and have a very low permeability. Based on our review of the available boring data at the site and the elevations of the older soil exposures in the bluff, the surface of these soils appears to slope to the north-northwest. SLOPE STABILITY In general, the native soils at the site consist of medium dense to dense recessional outwash over very dense glacially consolidated pre-Vashon sediments and bedrock. These materials are generally stable relative to deep-seated failure and appear to be stable in their existing condition. The undisturbed glacially consolidated soils at the site have very high strengths and are stable at very steep ('/a to 1 and steeper) slopes. We previously evaluated the slope stability of the south bluff area. The results of our evaluation are presented in our March 7, 1994 report. No evidence of deep-seated slope failure was observed. Weathering, erosion, and the resulting surficial sloughing and shallow landsliding are natural processes that affect steep slope areas. Instability of this nature is confined to the upper weathered or disturbed zone which has lower strength. Significant weathering typically occurs in the upper 2 to 3 feet and is the result of oxidation, root penetration, wet/dry cycles, and freeze/thaw cycles. Erosion in steep slope areas can be reduced and/or managed through proper design and construction of the development. This may include proper drainage control and/or retention/catchment systems. Erosion control recommendations for the slope areas are provided in the Setbacks, and Erosion and Sediment Control sections of this report. G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 5 SUBSURFACE CONDITIONS Subsurface conditions at the site were explored by excavating 21 track-hoe test pits, reviewing 6 borehole logs and pump test data, and reviewing 13 water well logs from Ecology files. Our test pits were excavated to depths of 6 to 20 feet below the existing ground surface. The locations of the test pits were selected based on the site map provided, which showed the planned location of the infiltration systems. The explorations were located in the field by pacing from existing features. The approximate locations of the test pits are shown on the Site Plan/Vicinity Map, Figure 1. The test pits were monitored by a representative from our firm. Soils encountered were examined and classified, and soil samples were obtained from immediately below the proposed pond bottom elevations. Soils encountered in the explorations were classified in general accordance with ASTM D-2488, the Standard Practice for the Classification of Soils (Visual- Manual Procedure). A description of this soil classification system is given in Figure 2. Logs of the explorations are included as Figures 3 through 11. Soil samples obtained at the planned pond-bottom elevation were tested to determine their gradation. The gradation curves are presented as Figures 11 through 14. In addition to our subsurface explorations, we reviewed the data from 6 test borings completed at the site in 1988. The borings ranged in depth from 25 feet to 99 feet below the ground surface. Monitoring wells were constructed in borings 1,2 3, 4 and 6. A pump test performed on well 6 with well 4 used as an observation well. An extraction slug test was conducted in well 2. The soils in the site area consist of Vashon recessional glacial outwash, erosional remnants of Vashon glacial till and Vashon advance outwash which overly older interglacial and glacial soils and Tertiary bedrock. The soils encountered in the explorations located in the old surface-mine bottom consist primarily of medium dense to dense Vashon advance sand with a variable silt content and localized variations in the gravel content. Localized and discontinuous lenses of silt and silty sand were frequently encountered in the test pits. The lenses ranged from a few inches to a foot or more in thickness. Ground water was typically perched on the lenses. Sandy fine gravel with a trace of silt was encountered in test pit 3 from the ground surface to a depth of about 7 feet where it is underlain by sand with a trace of silt. Sandy fine gravel and gravel with a trace of sand was encountered in test pits 15 through 17 to the full depths of the test pits, 8, 91, and 81/2 feet, respectively. Significant ground water flow was observed in the gravel units at depths of about 6 to 8 feet. Older interglacial soils were encountered in the test pits in the central portion of the site. In test pits 8 and 9, partially cemented silty fine sand over hard silt with clay were encountered below the advance sands. The silty sand was encountered at depths of 11 and 16 feet, G e o E n g i n e e r s File No.0291.006-T03 M.A. Segale, Inc. October 24, 1994 Page 6 respectively. In test pit 21, very stiff silt with clay was encountered at a depth of about 3 feet and extended to 7 feet where it is underlain by very stiff sandy silt. Ground water seepage was encountered in most of the test pits. The seepage ranged from very slight to significant. The small zones of perched ground water seepage on silty lenses was generally slight to moderate. The ground water seepage in the gravel units was significant. We understand that static water level in the monitoring wells located near the center of the site(4 and 5) was at 3 feet and 5 feet below the ground surface, respectively, on November 11, 1988. The borings encountered approximately 75 feet of Vashon advance sands. Below the advance sands, glaciofluvial and interglacial silty sand, silt and clayey silt were encountered, borings 3 and 5. Borings 4 and 5, drilled near the central portion of the site, encountered lenses of silty sand, sandy silt and clay at 181/2 and 251/2 feet, respectively. These silty units likely correlate with the silty units encountered in test pits 7, 8, 9 and 21. Ground water levels measured in the monitoring wells in November of 1987 were within several feet of the ground surface. Ground Water Systems There are records for 13 existing water wells located within 1 mile of the site. Data from these water wells, observed ground water seepage and our review of the GAI data constitute the basis for describing the characteristics of the aquifer system for the site area. There appears to be at least two distinct ground water (aquifer) systems within the project area. The Vashon advance outwash unconfined aquifer and a deeper pre-Vashon aquifer. Water wells in the area typically remove water from the deeper pre-Vashon confined aquifer. Several City of Renton wells are located about 1 mile southwest of the site and withdraw water from the deeper pre-Vashon confined aquifer. In addition, several wells located south of the site in the Cedar River Valley remove water from the shallow alluvial sediments. Providing that at least 50 percent of the surface water is recharge on site, it is our opinion that there will be no decrease in water available for withdrawal at the several wells and shallow water system. The Vashon advance aquifer in the site area consists of stratified sand and gravelly sand deposited during the southward advance of glacial ice. These deposits are interbedded with localized relatively low-permeability zones of silt and clay. This aquifer is a source of water for a surface water system (spring) located west of the site. This aquifer is largely unconfined (an unsaturated zone exists between the base of the overlying till, where present, and the water level within the aquifer). The thickness of the saturated zone is influenced by the relief of the surface of the underlying older deposits and by horizontal and vertical variations in permeability. These permeability variations are related to zones of soil containing variable amounts of silt and clay or significant changes in density. G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 7 We understand that a private water system, for irrigation purposes only, is located west of the northwest corner of the site. The water system is situated within the natural drainage channel that leaves the site and is fed, at least partially, by spring flow. The water system is reported to have a water rights claim for 250 gpm (gallons per minute). Ground Water Flow Patterns Ground water flow patterns have both vertical and horizontal components. In the site area, the primary vertical component of flow is downward percolation through the recessional outwash and till, where present, and into the advance outwash aquifer. Some portion of the water likely infiltrates through the underlying silty sediments and to deeper pre-Vashon aquifer systems. The horizontal ground water flow pattern in the site area is controlled by less permeable or confining zones within and/or below the aquifer, the direction of dip or slope of the confining surfaces, hydraulic head, and both the regional and local topography. As previously discussed, the projected surface slope of the glaciofluvial/interglacial sediments appears to be to the northwest. Infiltrated water or ground water in this area would, therefore, flow to the northwest, at least locally. This is also supported by the lack of evidence of significant ground water seepage occurring on this portion of the bluff face. Based on our geologic reconnaissance and our review of the well logs in the site area, the ground water flow direction for the Vashon advance outwash aquifer at the site is to the west. The hydraulic gradient, or slope on the ground water surface, at the site is reported to be on the order of 0.01 to west. Ground Water Recharge The recharge to the overall aquifer system is by direct precipitation and infiltration over the entire upland area. Under existing conditions,precipitation that falls on the site rapidly infiltrates into the granular soils and recharges the aquifer systems. As the site is developed, potential changes in the surface coverage could modify the infiltration patterns at the site. The proposed development plans include infiltration of the storm water runoff from impervious surfaces at the site through designed infiltration system. Although local changes in the infiltration pattern and shallow ground water flow may occur, no net change in the overall ground water recharge or flow direction is expected as a result of the proposed site development. Water collected from the roadways will be treated in accordance with regulation requirements and then infiltrated through designed systems. CONCLUSIONS AND RECOMMENDATIONS Based on our data review, site reconnaissance and subsurface explorations, it our opinion that the site is suitable for the proposed development. No changes in ground water recharge or flow direction at the site are expected as a result of the proposed development. Precipitation that G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 8 currently falls on the site infiltrates rapidly into the granular soils that cover most of the site. As the site is developed, the amount of impervious surface area at the site will increase. Storm water runoff from these areas will be collected and diverted to designed infiltration systems that will maintain the current infiltration levels at the site. The amount of water infiltrated at the site will not change significantly,however, the infiltration area or pattern will change. Although this may affect the local shallow ground water flow patterns, no significant adverse impact is expected. Currently, a base flow of ground water is collected in a topographic basin located in the northwest portion of the site, and conveyed off-site. To maintain the existing site water balance, this discharge must be maintained. The proposed infiltration systems will provide adequate recharge to maintain the water balance in the area and maintain the downstream 250 gpm spring flow. Slopes located on the site are stable relative to deep seated failure and will not be affected by the proposed development provided our recommendations are incorporated into the development plans. The areas of erosion and surficial ravelling and sloughing that occur at the site are the result of natural processes. The proposed structures can be satisfactorily supported on medium dense to dense native soils or on adequately compacted structural fill in conformance with the manufactures' guidelines. Building setbacks from the top and toe of slopes and slope setbacks from existing transmission line towers are provided in the Setbacks section of this report. The sand and gravel soils encountered at the site are suitable for use as structural fill. Silty soils encountered locally are moisture sensitive and will be difficult to compact during wet weather conditions. Pertinent conclusions and geotechnical recommendations regarding the design and construction of the proposed development are presented below. STORMWATER INFILTRATION/GROUND WATER RECHARGE In our opinion, infiltration of storm water is feasible at the site and will, in effect, maintain the existing recharge of the ground water system. The advance outwash granular soils should have adequate permeability to infiltrate storm water from the site, provided adequate design, construction and maintenance practices are used. Storm water runoff collected from the drive and roadway areas will be infiltrated after treatment in accordance with current regulatory requirements. Three infiltration ponds(A, B and C) will be constructed in the central and west portions of the site. The locations of the ponds are shown on the Figure 1. Current plans include raising grades in the portion of the site proposed for storm water infiltration. To provide additional filtration of the roadway storm water, we recommend that the G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 9 fill consist of a granular soil material placed as a filter blanket. Typically this consists of medium to coarse grain sand. Specific grain-size design criteria will be provided at your request. Storage capacity of the soils and possible ground water mounding during wet weather conditions may have an impact on the final design of the pond infiltration systems. We recommend that a select fill material, gravel, be used to provide additional storage capacity above the existing water table and enhance infiltration of the storm water. Storm water infiltration rates for site soils were calculated based on the grain-size distribution of select soil samples and their corresponding soil textures. The U.S. Department of Agriculture Textural Triangle provided in the Stormwater Management Manual for the Puget Sound Basin, published in February 1992, was used to determine the soil textures and the infiltration rate. Representative soil samples were collected at the elevations of the proposed infiltration pond bottoms below the filter. The theoretical stormwater infiltration rates for the soil samples analyzed is about 8 inches per hour. This rate of infiltration would occur until the underlying soil is saturated and the water table is mounded above the bottom of the pond. When the top of the mound is above the bottom of the pond, the effective infiltration rate is equivalent to the dissipation rate of the mound. Important factors affecting the dissipation are the size and shape of the infiltration area, depth to the water table, and other factors. For percolation area B, we calculate a dissipation rate of 4 to 6 inches per hour. Based on this, a design percolation rate of 4 inches per hour is recommended. The dissipation rate for area C is calculated to be 4 inches per hour, and a percolation rate of 4 inches per hour is recommended. For area A, the dissipation rate is calculated to be approximately 2 to 2' inches per hour. In order to increase the effective rate to 4 inches per hour, we recommend the construction of a gravel infiltration blanket that extends north of the infiltration pond. The area of the infiltration blanket should be approximately the same as the bottom area of the ponds (76,800 sq. ft.) to provide an effective percolation rate of 4 inches per hour in the pond. We recommend the gravel blanket be 4 feet thick and approximately 100 feet wide. The base of the gravel should be at the same level as the bottom of the filter blanket. Extending the gravel blanket north of pond A to the region where gravel was encountered will significantly increase percolation and provide a margin of safety. A schematic section is provided as Figure 15. Storm water should be treated in accordance with current regulations prior to infiltration. We understand that wet ponds will be used for treatment of the stormwater runoff. Suspended solids could eventually clog the soil and reduce the infiltration rate if allowed to enter the ponds during construction. Because of the potential for clogging, temporary storage and handling of surface water ponds should be done until after construction is complete and the site is paved and landscaped. Periodic sweeping of the paved areas will help extend the life of the infiltration system. G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 10 Infiltration of the storm water at the site will match existing recharge conditions at the site and maintain recharge to the down-gradient water supply system. No adverse impact to the existing water system is expected. The existing collection and discharge of ground water in the west portion of the site will be maintained by the proposed storm water collection and infiltration systems. SLOPE STABILITY Based on our field observations, data review, subsurface explorations and experience, we conclude that the slopes at the site are stable relative to deep-seated failure. No changes in slope stability are expected as a result of the proposed development. Sloped areas of 1 1h to 1 or steeper are currently experiencing erosion and surficial ravelling and sloughing. If measures recommended in this report are implemented, these natural processes can be expected to be retarded and sloped areas stabilized/protected as a result. SETBACKS The City of Renton restricts building on slopes of 40 percent or greater. The building setbacks from the top of slope along the south bluff which we previously provided(ranging from 25 to 40 feet from the top of the bluff) can likely be reduced based on your final grading plan and foundation designs. In other areas of the site where were structures or roadways are proposed near the toes of slopes, we recommend that catchment systems/wall be constructed using Ecology blocks or comparable materials, or that structures be set back a minimum of 8 feet. For planning purposes we recommend a setback of 15 feet from the foundation/pole of existing transmission lines to the top of 11/2 to 1 cut slopes. Erosion control measures should be provided to minimize any potential erosion and surficial ravelling. If the slopes are 11:1 or less, we believe the potential for erosion is minimal. EARTHWORK Site Preparation Most of the site area was previously cleared and graded incidental to surface-mining operations. Remaining vegetated or revegetated areas to be graded should be cleared of deleterious matter including debris and organic materials. Graded areas should be stripped of any forest duff and organic-laden soils. Based on our site observations, we estimate that stripping on the order of 2 or 4 inches will likely be necessary to remove the root zone and surficial soils containing organics in the vegetated areas of the site. Areas with deeper, unsuitable organics should be expected in the vicinity of man-made water/silt control structures created incidental to mining. Stripping depths of up to 1 foot are likely in these areas. G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 11 If the clearing operations cause excessive disturbance, additional stripping depths may be necessary. Disturbance to a greater depth should be expected if site preparation work is done during periods of wet weather. The organic-laden strippings can be stockpiled on-site and later used for landscaping purposes. Materials which cannot be used for landscaping should be removed from the project site. Following stripping and prior to placement of fill, the exposed subgrade areas should be compacted to a firm and unyielding surface. In fill areas, we recommend that trees be removed by overturning so that a majority of the roots are removed. Excavations for tree stump removal should be backfilled with structural fill compacted to the densities described in the Structural Fill section. We recommend that the exposed subgrade conditions be evaluated after removal of vegetation and topsoil stripping is completed and prior to placement of structural fill. The exposed subgrade soil should be proofrolled with heavy rubber-tired equipment during dry weather or probed with a 1/2-inch-diameter steel rod during wet weather. Silty surficial soils in the vicinity of the drainage swale should not be proofrolled if they contain excessive moisture. Any soft, loose or otherwise unsuitable areas delineated during proofrolling or probing should be recompacted, if practical, or overexcavated and replaced with structural fill, based on the recommendations of our site representative. Structural Fill All new fill material used to achieve design grades within the building and roadway areas should be placed as structural fill. The structural fill should be placed in horizontal lifts of appropriate thickness to allow adequate and uniform compaction of each lift. Fill placed in the building and pavement areas should be compacted to at least 95 percent of MDD (maximum dry density as determined in accordance with ASTM D-1557). The appropriate lift thickness will depend on the fill characteristics and compaction equipment used. The suitability of material for use as structural fill will depend on the gradation and moisture content of the soil. As the amount of fines (material passing No. 200 sieve) increases, soil becomes increasingly sensitive to small changes in moisture content and adequate compaction becomes more difficult to achieve. During wet weather, we recommend use of well-graded sand and gravel with less than 5 percent passing the No. 200 sieve based on that fraction passing the 3/4-inch sieve. Material placed for structural fill should be free of debris, organic matter, trash and cobbles greater than 6 inches in diameter. Particle sizes larger than 3 inches should be excluded from the top 1 foot of fill. The moisture content of the fill material should be adjusted as necessary for proper compaction. G e o E n g i n e e r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 12 Suitability of On-Site Materials as Fill During dry weather construction, any nonorganic on-site soil may be considered for use as structural fill, provided it meets the criteria described above in the structural fill section and can be compacted as recommended. If the material is over-optimum moisture content when excavated, it will be necessary to aerate or dry the soil prior to placement as structural fill. In general, the granular soils (sand and gravel) observed in our test pits and encountered in the borings with less than 10 percent fines (material passing the No. 200 sieve) may be used as structural fill. This material is comparable to commercial "pit run" sand and gravel. Cleaner" material, less than 5 percent fines, will be suitable as structural fill during wet weather conditions. Most of the site soils will likely meet this criteria. CUT AND FILL SLOPES Temporary cut slopes may be necessary during grading operations. As a general guide, temporary slopes of 11/2 to 1 (horizontal to vertical) or flatter may be used for temporary cuts in the upper 3 to 5 feet of the glacially consolidated soils that are weathered to a loose/medium dense condition. Temporary slopes of 1 to 1 or flatter may be used in the unweathered dense to very dense sands and gravels or till. These guidelines assume that all surface loads are kept at a minimum distance of at least one half the depth of the cut away from the top of the slope and that significant seepage is not present on the slope face. Although no significant seepage is expected, flatter cut slopes will be necessary if encountered. We recommend a maximum of 11 to 1 for permanent cut slopes and 2 to 1 for permanent fill slopes. Where the recommended slopes are not feasible, catchment or retaining structures are recommended. In addition, we recommend that new cut slopes of 11/ to 1 be covered with jute mat and hydroseeded. Fill placed on slopes that are steeper than 5 to 1 should be "keyed" into the undisturbed native soils by cutting a series of horizontal benches. The benches should be 11/ times the width of equipment used for grading and a maximum of 3 feet in height. Subsurface drainage may be required in seepage areas, if encountered. Surface drainage should be directed away from all slope faces. Some minor raveling may occur with time. All new and existing slopes should be seeded as soon as practical to facilitate the development of a protective vegetative cover or otherwise protected. BUILDING FOUNDATIONS The proposed manufactured/modular homes should be supported in accordance with the manufactures' recommendations. Spread footings will likely provide adequate support for the proposed structures. Footings which bear on dense native soil or on structural fill compacted to at least 95 percent of the MDD can be designed using an allowable soil bearing pressure of 2,000 psf for combined dead and long-term live loads, exclusive of the weight of the footing and G e o E n g i nee r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 13 any overlying backfill. This value may be increased by one-third for transient loads such as those induced by seismic events or wind loadings. We recommend a minimum width of 2 feet for isolated footings and 16 inches for continuous wall footings. We expect that specific requirements for stabilizing the manufactured home units will be required. Based on the type of system used, specific geotechnical criteria can be provided for the various systems. We estimate that settlements of footings designed and constructed as recommended will be less than 1/2 inch, with differential settlements between comparably loaded footings of 1/2 inch or less. Settlements will occur essentially as loads are applied. Disturbance of the foundation subgrade during construction could result in larger settlements than predicted. LIMITATIONS We have prepared this report for M.A. Segale, Inc., the property owner, and their agents for use in the design of geotechnical parameters and storm water infiltration systems for this project. Our conclusions and recommendations are based on widely spaced explorations and subsurface conditions between the explorations may vary from those reported. Subsurface conditions should be monitored during construction to evaluate the consistency of soil type and grain size. It may be necessary to modify the design of the stormwater infiltration systems if soil conditions differ from those encountered in the test pits. Our report, conclusions and interpreta- tions should not be construed as a warranty of the subsurface conditions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with generally accepted practices in this area at the time this report was prepared. No warranty, express or implied, should be understood. O G e o E n g i nee r s File No.0291-006-T03 M.A. Segale, Inc. October 24, 1994 Page 14 We appreciate the opportunity to be of service to Segale Business Park. Please call if you have questions regarding this report. Yours very truly, 1. HEk 4, GeoEngineers, Inc. ov w fi cf) ; •-•%7 , z_41 79'` iF ISTES$ G 4g Engi eering Geol ist s/ONAL 81 EXPIRES_V Ro/q4 Gar42,,,,„4„4,0„.. 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SOIL CLASSIFICATION SYSTEM GROUP MAJOR DIVISIONS SYMBOL GROUP NAME GRAVEL CLEAN GW WELL-GRADED GRAVEL,FINE TO COARSE GIAVEL COARSE GRAVEL GRAINED GP POORLY-GRADED GRAVEL SOILS More Than 50% of Coarse Fraction GRAVEL GM SILTY GRAVEL Retained WITH FINES on No. 4 Sieve GC CLAYEY GRAVEL More Than 50% SAND CLEAN SAND SW WELL-GRADED SAND, FINE TO COARSE SAN') Retained on No. 200 Sieve SP POORLY-GRADED SAND More Than 50% of Coarse Fraction SAND SM SILTY SAND Passes WITH FINES - No. 4 Sieve SC CLAYEY SAND FINE SILT AND CLAY ML SILT GRAINED INORGANIC SOILS CL CLAY Liquid Limit Less Than 50 ORGANIC OL ORGANIC SILT, ORGANIC CLAY More Than 50% SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT Passes INORGANIC - CH CLAY OF HIGH PLASTICITY, FAT CLAY No. 200 Sieve Liquid Limit 50 or More ORGANIC OH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: SOIL MOISTURE MODIFIERS: 1. Field classification is based on visual examination of soil Dry- Absence of moisture,dusty, dry to the touct in general accordance with ASTM 02488-90. Moist- Damp, but no visible water 2. Soil classification using laboratory tests is based on ASTM D2487-90. Wet- Visible free water or saturated, usually s, it is obtained from below water table 3. Descriptions of soil density or consistency are based on interpretation of blow count data, visual appearance of soils, and/or test data. SOIL CLASSIFICATION SYSTEM Geo Engineers FIGURE 2 LOG OF TEST PIT DEPTH BELOW' SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 1 0.0-9.5 SP Brown fine to medium sand with a trace of silt and occasional gravel(mediu:a dense to dense,moist to wet) Test pit completed at a depth of 9.5 feet on 09/19/94 Moderate ground water seepage observed at approximately 8.0 feet Severe caving observed Disturbed soil sample obtained at a depth of approximately 4.0 feet TEST PIT 2 0.0-6.5 SP Brown fine to medium sand with a trace of silt(medium dense to dense, moist to wet) Lenses of fine sand with silt @ 6.0 feet Test pit completed at a depth of 6.5 feet on 09/19/94 Moderate ground water seepage observed at approximately 6.0 feet Severe caving observed TEST PIT 3 0.0-7.0 SP Brown sandy fine gravel with a trace of silt(medium dense to dense,moist; 7.0- 10.0 SP Brown fine to medium sand with a trace of silt(dense to very dense,moist) Test pit completed at a depth of 10.0 feet on 09/19/94 No ground water seepage observed Moderate to severe caving observed Disturbed soil sample obtained at a depth of approximately 2.0 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. tpLOG OF TEST PIT Geo`O Engineers FIGURE 3 LOG OF TEST PIT DEPTH BELOW SOIL GROUP CLA SSIFICATIONSURFACE FEET) SYMBOL DESCRIPTION TEST PIT 4 0.0-2.0 SP Dark brown fine to coarse sand with a trace of silt and occasional gravel(m:dium dense,moist) 2.0-4.5 GP Dark brown sandy gravel with a trace of silt(medium dense to dense,moist) 4.5- 12.0 SP Dark brown fine to medium sand with a trace of silt(dense to very dense,wet) Test pit completed at a depth of 12.0 feet on 09/19/94 Slight ground water seepage observed at approximately 4.0 feet Severe caving observed Disturbed soil sample obtained at a depth of approximately 3.0 feet TEST PIT S 0.0- 14.0 SP Brown fine to medium sand with a trace of silt(medium dense to very dense,.moist) Test pit completed at a depth of 14.0 feet on 09/19/94 No ground water seepage observed Severe caving observed TEST PIT 6 0.0- 15.5 SP Brown fine to medium sand with a trace of silt and occasional gravel(medium dense to very dense,moist to wet) Test pit completed at a depth of 15.5 feet on 09/19/94 Slight ground water seepage observed at approximately 5.5 and 11.0 feet Severe caving observed THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. AV; LOG OF TEST PIT Geo Engineers FIGURE 4 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 7 0.0-3.0 SP-SM Brown gravelly fine to medium sand with silt(medium dense,moist) 3.0-6.5 SP Brown fine to medium sand with a trace of silt(dense,moist) 6.5-8.0 SM Gray silty fine sand(dense to very dense,wet) 8.0- 18.5 SP Gray fine sand with a trace of silt(dense to very dense,wet) Test pit completed at a depth of 18.5 feet on 09/19/94 Slight ground water seepage observed at approximately 2.0 and 8.0 feet Severe caving observed TEST PIT 8 0.0-2.0 SP Brown fine to medium sand with gravel and a trace of silt(medium dense,r,ioist) 2.0-7.0 SP Dark gray fine to medium sand with a trace of silt and oerosional gravel(d;nse to very dense,moist to wet) 7.0- 11.0 SP Brown fine to medium sand with a trace of silt(very dense,moist to wet) 11.0- 13.0 SM Tan silty fine sand(very dense,moist) 13.0- 16.0 ML Bluish gray silt with clay(hard,moist) Test pit completed at a depth of 16.0 feet on 09/19/94 Very slight ground water seepage observed at approximately 2.0 and 11.0 feet Moderate caving observed Disturbed soil sample obtained at a depth of approximately 8.0 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. LOG OF TEST PIT Geo l Engi eers FIGURE 5 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 9 0.0-3.0 GM Brown gravel with sand and silt(very dense,moist) 3.0- 16.0 SP Brown fine to medium sand with a trace of silt(very dense,moist) 16.0- 17.5 SM Tan silty fine sand(very dense,moist) 17.5-20.0 SM Brown silty sand with gravel(very dense,moist)(cemented) Test pit completed at a depth of 20.0 feet on 09/19/94 No ground water seepage observed Minor caving observed TEST PIT 10 0.0- 1.0 SM Gray silty sand with gravel(very dense,moist) 1.0- 19.0 SP Brown fine to medium sand with a trace of silt(very dense,moist) Test pit completed at a depth of 19.0 feet on 09/19/94 No ground water seepage observed Minor caving observed TEST PIT 11 0.0-2.5 SP-SM Dark brown fine to coarse sand with silt and gravel(dense,moist) 2.5-6.0 SP Light brown fine to medium sand with a trace of silt(medium dense to dense, aoist) 6.0-9.5 SP-SM Gray fine to medium sand with silt(medium dense,moist) 2 foot layer of hay and rotted wood 9.5- 14.0 SP Brown fine to medium sand with a trace of silt and occasional gravel (medium dense,moist) 14.0- 16.5 SP Grades to medium sand(medium dense to dense,wet) Test pit completed at a depth of 16.5 feet on 10/17/94 Ground water seepage observed at a depth of 14.0 feet Caving at and below seepage Disturbed soil sample obtained at a depth of 5.5 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. OP LOG OF TEST PIT Geo ~ Engineers FIGURE 6 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 12 0.0-2.7 SP Brown fine to medium sand with gravel and a trace of silt(medium dense to do nse, moist) 2.7-3.5 SP Brown gravelly fine to coarse sand(dense,moist) 3.5-4.5 SP-SM Dark brown fine to medium sand with silt and gravel(dense,moist) 4.5-6.0 GP Brown sandy gravel(dense,moist) 6.0-9.0 SP Brown gravelly fine to medium sand(dense,moist) 9.0- 10.5 SP-SM Gray fine to medium sand with silt partings(dense,moist) 10.5- 15.0 SP-SM Brown fine to medium sand with gravel and silt partings(dense,moist) Test pit completed at a depth of 15.0 feet on 10/17/94 Ground water seepage observed at 14.0 feet Caving observed at 14.0 feet Disturbed soil samples obtained at depths of 2.0,3,0 and 13.5 feet TEST PIT 13 0.0- 1.5 GP-GM Brown sandy gravel with silt(medium dense,moist) 1.5-3.5 SP Brown medium sand with gravel and a trace of silt(dense,moist) 3.5-4.5 GP-GM Dark brown gravel with silt and sand(dense,moist) 4.5-7.0 SP-SM Light brown fine to medium sand with silt and occasional gravel(dense,moist) 7.0- 12.5 SP Gray fine to medium sand with a trace of silt(dense,moist) 3-foot layer of organic material and tree parts 12.5- 13.0 SM Gray fine silty sand(dense,moist) 13.0- 16.0 SP-SM Brown fine to medium sand with silt(dense,moist) Test pit completed at a depth of 16.0 feet on 10/17/94 No ground water seepage observed No caving observed Disturbed soil samples obtained at depths of 4.0,and 5.0 feet THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. LOG OF TEST PIT Geo.O Engineers FIGURE 7 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 14 0.0- 1.5 GP Brown sandy gravel with a trace of silt(medium dense,moist) 1.5-5.0 SP Brown fine to medium sand with a trace of silt and occasional gravel(dense moist) 5.0- 15.0 SP-SM Gray fine to medium sand with silt(dense,moist) Increasing particle size and decreasing silt content with depth Grades to wet Test pit completed at a depth of 15.0 feet on 10/17/94 Ground water seepage observed at 14.0 feet Caving observed at 14.0 feet Disturbed soil sample obtained at a depth of 3.5 feet TEST PIT 15 0.0-2.0 SP Light brown fine to medium sand with a trace of silt and occasional gravel(i iedium dense,moist) 2.0-8.0 GP Brown sandy gravel(medium dense to dense,moist) Grades to gravel with a trace of sand(medium dense to dense,wet) Test pit completed at a depth of 8.0 feet on 10/17/94 Ground water seepage observed at 4.5 feet,with a significant flow at 6.0 fe:t Severe caving observed Disturbed soil sample obtained at a depth of 5.0 feet TEST PIT 16 0.0-2.0 SP-SM Brown gravelly fine to medium sand with silt(medium dense,moist) 2.0-9.5 GP Gray sandy gravel(medium dense to dense,moist) Grades to wet Test pit completed at a depth of 9.5 feet on 10/17/94 Ground water seepage observed at 8.0 feet Severe caving observed THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. LOG OF TEST PIT Geo\`Engineers FIGURE 6 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 17 0.0-2.5 GP Brown sandy gravel with a trace of silt(medium dense,moist) 2.5-5.5 GP Gray sandy gravel(medium dense to dense,moist) 5.5-8.5 GP Brown gravel with sand and a trace of silt(medium dense to dense,wet) Test pit completed at a depth of 8.5 feet on 10/17/94 Ground water seepage observed at 8.0 feet Caving observed at 3.0 feet TEST PIT 18 0.0-6.0 SP Light brown fine to medium sand with occasional gravel and a trace of silt medium dense,moist) Grades to medium dense to dense,wet) Grades to wet Test pit completed at a depth of 12.0 feet on 10/17/94 Ground water seepage observed at 6.0 feet Caving observed at 5.0 feet TEST PIT 19 0.0-3.0 GP Brown gravel with sand and a trace of silt(medium dense,moist) 3.0-8.0 SP Brown fine to medium sand with a trace of silt and occasional gravel medium dense,moist to wet) Test pit completed at a depth of 8.0 feet on 10/17/94 Ground water seepage observed at 6.0 feet Severe caving observed THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. 4 LOG OF TEST PIT Geo, Engineers FIGURE 9 LOG OF TEST PIT DEPTH BELOW SOIL GROUP GROUND SURFACE CLASSIFICATION FEET) SYMBOL DESCRIPTION TEST PIT 20 0.0- 1.0 GP Dark brown sandy gravel with a trace of silt(medium dense,moist) 1.0-7.0 SP Brown fine to medium sand with occasional gravel and a trace of silt (medium dense,moist to wet) Test pit completed at a depth of 7.0 feet on 10/17/94 Ground water seepage observed at 6.0 feet Severe caving observed TEST PIT 21 0.0-3.0 SP Brown fine to medium sand with occasional gravel and cobbles and a trace of silt dense to medium dense,moist) 3.0-7.0 ML Gray silt with clay and a trace of sand(very stiff, moist) 7.0- 10.0 ML Gray sandy silt(very stiff,moist) Test pit completed at a depth of 10.0 feet on 10/17/94 No ground water seepage observed No caving observed THE DEPTHS ON THE TEST PIT LOGS,ALTHOUGH SHOWN TO 0.1 FOOT,ARE BASED ON AN AVERAGE OF MEASUREMENTS ACROSS THE TEST PIT AND SHOULD BE CONSIDERED ACCURATE TO 0.5 FOOT. OP pp LOG OF TEST PIT Geo.,Engineers FIGURE 10 rr1 r- 0291-008-T03 dPB:GWH.wc 09/29/94 U.S.STANDARD SIEVE SIZE 3' 1.5' 3/41/2'3/8' #4 #10 #20 #40 #60 #100 #200 M100 CD h...q......p........... r.....q... q ..w.......... 0 90 - llla 70 - V CD jai 50 -............. q............w.... a w 40 - w Q. —....:..w...... . q w............n.......q...q..... n....w...n.......... 20 - 10 —..q...q......q.... q........... q....p... . q.......... OT73 0 I I I I T I I 11 1 ITIII I 11 I I I I I II I I I I I I II 11 1 1 I I I II 1 1 1 1 1 1 II 0 1,000 100 10 1 0.1 0.01 0.001 n .D- 1 GRAIN SIZE IN MIWMEI tFib O O C Z rn C COBBLES GRAVEL SAND SILT OR CLAY COARSE I FINE COARSE MEDIUM I FINE a DJ a < m EXPLORATION SAMPLENSYMBOL SOIL DESCRIPTIONNUMBERDEPTH(FEE0 TP-1 4.0 Fine to medium sand with a trace of silt and occasional gravel 0291-008-TW vr'B:GWH:vc 09/29/94 U.S.STANDARD SIEVE SIZE 3' 1.5' 3/41/2'3/8' #4 #10 #20 #40 #60 #100 #200 100 I I I I I I J I I I I I 1 J p............a.... a..y....0........ y.y..4... a ..0... 0 90 — 14 80 —1'''' 1\- 70 —.._...w...... 7w....w....... cii: 60 — CD 4 J.................J J...... .....J....a 4...a.... J ..J..,....v... J .....4...... Z w.. w..........CA w...q..p... q y.................y q......... .w....q w.......y...q.... y ... ..q... CO L% 40 UOCJ...... 4 SJ.................J J............4....a 5................4.J..J... W a- 30 —..w.q.q..q... q y.................y y....q .... ...............q.... w....w... q ..w...w..q... 20 — 10 _..a...4...... 4 a a............0....a 4....4... 4 ..0.......... 71 0 I 1 11 1 1 I I 1 1 1 1 1 1 1 1 I 1 I 1 1 1 1 1 1 I 1 I 1 1 1 1 1 1 1 I 1 1 1 1 1 1 I I I 1 D 0 1,000 100 10 1 0.1 0.01 0.001 f -Di GRAIN SIZE IN MIWMETERS O O C Z DTI C COBBLES GRAVEL SAND SILT OR CLAY COARSE FINE COARSE MEDIUM FINE XI 11 < m p SYMBOL EXPLORATION SAMPLE NUMBER DEPTH(FEET) SOIL DESCRIPTIONS TP-3 2.0 Sandy fine gravel with a trace of silt I I I i I I I I I ry i 0291-005-TO3 BPB:GYVH:vc 09/29/94 U.S.STANDARD SIEVE SIZE 3' 1.5' 3/41/2'3/8' #4 #10 #20 #40 #60 #100 #200 g'"' 100 I J I I I J I 1 1 I I I q...q...... q.................q q............q....q q.......q...q.q..q...q...q...... O 90 illy q...q...... q .................J q...... ...p....q q..... ...4.... q....y... q ..q...q...... g' 70 CD CD0 _........4...... 4 4 ..5. 4.. z n.p.q.....• q q ....«.q..«... q ..«...«....q co 40 — W UL.J....... J 5...4...... CC w0- 30 ..q...q..q... q q............q....q q............q....q q....q...q.... q.p..q... q ..q...q....., q 20 — t 4._..4... 4 J 4 10 ..q...q...... q ............. q............q....q.......q........... .... 4... 4 ..q.......... t.... s ..............«.......-...«..... .. q XI 0 11 1 1 1 1 1 1 1 f 1 1 l I 1 1 I . 1 1 1 1 i 1 7 1 7 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 I I 11 1 1 1 i D 0 1.000 100 10 1 0.1 0.01 0.001 i -I GRAIN SIZE IN MILLIMETERS O OCZ III C COBBLES GRAVEL SAND SILT OR CLAY COARSE FINE COARSE MEDIUM FINE al W < 1 U) EXPLORATION SAMPLESYMBOL NUMBER DEPTH(FEE I) SOIL DESCRIPTION TP-4 3.0 Sandy gravel with a trace of silt I I i iIII ' I 0291-008-T03 BPB:GWH:vc 09/29/94 II U.S.STANDARD SIEVE SIZE S' 1.5' . 3/41/2'3/8' #4 #10 #20 #40 #60 #100 #200 100 I I I I I I I I I I I I CD 9......9 q...........¢.... 4.q..0... O ..q...¢...... 0 all — 1 i i 0......0 4•...........9....a 9..... .......... 4.9..4... 9 ..0.......... i 70 —.._... ..i.... r 7...w....... 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(File No. 0171-031-R02) AnMarCo (File No. 3473-001-R02) INTRODUCTION This report summarizes our conclusions regarding an appropriate building setback from the top of slope related to a proposed development for manufactured homes in Renton, Washington. The development planning is a combined effort of M.A. Segale, Inc. and AnMarCo. Our services have been performed jointly for the two owners. The basis for our services is described in our confirming agreements to the two owners dated January 7, 1994. The project site is located north of Maple Valley Road (SR 169), south of Northeast Third Street, and generally between the alignments of Blaine Avenue Northeast and Monroe Avenue Northeast. A vicinity map and a site map are attached as Figures 1 and 2, respectively. GeoEngineers,Inc. 8410 154th Avenue N.E. Redmond,WA 98052 Telephone(206)861-6000 Fax(206)861-6050 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 2 The proposed manufactured home project (MHP) will occupy two adjacent parcels of land totaling about 165 acres. Approximately 125 acres of the combined site is owned by M.A. Segale and 40 acres is owned by AnMarCo (Figure 2). We understand that a total of about 400 manufactured homes and 100 single-family homes are planned, along with typical utility and street improvements. About 400 manufactured homes will be located on approximately 100 acres of the Segale land, and about 100 single-family homes will be located on approximately 25 acres of the AnMarCo land. We understand the streets and utilities will be constructed in accordance with city of Renton specifications. Each of the manufactured home building sites will be provided with typical power, telephone, water and sanitary sewer utilities. Storm drainage from each project will be collected and controlled through an integrated storm sewer system. No uncontrolled stormwater will be permitted to flow on the surface over the adjacent bluff; a more detailed description of the bluff is provided below. All of the storm runoff for the Segale parcel will be directed to a detention pond facility which will be located near the north center of the Segale parcel. Sanitary sewage will be directed to a gravity trunk sewer line and routed to an existing Metro sanitary sewer located along Maple Valley Road. The proposed trunk sewer will descend from the upland development area to Maple Valley Road via a bored pipeline, which does not yet exist. The pipeline bore will be located near the south-center of the Segale parcel. Design of the pipeline bore is not a topic of thi: evaluation. We understand that storm runoff for the AnMarCo parcel will be culverted to an existing storm sewer along Maple Valley Road. Sanitary sewage will be directed from the AnMarCo property to an existing sanitary sewer system in the Monterey Terrace plat to the north. We understand that a significant amount of grading is contemplated within the interior of the MHP, but only minor grading is planned along the bluff that forms the south margin of the development project. Details of the site conditions and grading are provided below. The home units located along the top of the bluff will be oriented approximately perpendicular to the crest alignment of the bluff. Each manufactured home will be supported on a structural foundation; the foundation details have not been completed at this time. SCOPE OF SERVICES The purpose of our geotechnical services is to evaluate stability conditions along the top of the bluff near the southern project margin as a basis for recommending an appropriate minimum building setback from the top of bluff. Specifically our services include: 1. Review current and historical topographic maps, geologic publications and aerial photographs of the project site. 2. Review geotechnical studies by our firm and by others that are relevant to the proposed project. G e o E n g i n e e r s File No.0171-031-R02/3473-001-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 3 3. Perform a detailed reconnaissance of the bluff area within the property. 4. Perform a preliminary bluff stability analysis based on topographic and soil properties and utilizing a computer modeling procedure. 5. Summarize our opinions and recommendations concerning the proposed setback in a letter report. DOCUMENT REVIEW Our evaluation of existing and future bluff stability is based on analysis of current and past conditions. Past conditions include geologic history of the site and changes resulting from previous mining and adjacent land development (road construction) activities. Future conditions are those that will result from the proposed development and from natural processes. We reviewed aerial photographs taken in 1936, 1946, 1968 and 1985. These photographs illustrate changes in vegetation and bluff conditions together with changes in regional land use. Conditions along the subject bluff were also compared on topographic maps dated 1962 and recent site surveys. A survey of the existing top of bluff was prepared by Boyd & Associates in December 1993. Geologic maps of the area have been compiled by various agencies and consultants. These maps help to (1) define the character and description of geologic units, (2) correlate surface exposure with regional stratigraphy, and (3) define the physical properties of specific soil units. Our reconnaissance was performed to confirm the geologic and soil conditions described in past studies applicable to the project area. The reconnaissance also documented existing conditions at a scale appropriate for evaluating future bluff stability performance related to the proposed development. Our analysis of bluff stability includes constructing several cross sections, which are in turn examined using XSTABL computer analyses and involving the soil and geologic properties described below. This report summarizes our observations and conclusions; the details of our analyses are maintained in our files. SITE CONDITIONS GENERAL The proposed development is on an upland north of the Cedar River. A bluff that forms the north wall of the Cedar River valley also forms the south margin of the proposed development area. Virtually all of the upland portion of the site has been surface-mined in the past for sand and gravel. The mining was conducted over several decades by various operators. The existing residential community of Monterey Terrace and the Mount Olivet Cemetery are located immediately north of the AnMarCo property. Both the residential community and the cemetery are several decades old. A King County transfer station and a large King County maintenance shop installation are located northeast of the Segale property. The Maplewood G e o E n g i nee r s File No.0171-031-R02/3473-OOi-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 4 residential plat is located on the valley floor south of the eastern portion of the Segale property. Two powerline rights-of-way traverse the western and north-central portions of the Segale property. One right-of-way extends north to south along the western margin of the Segale property; the second extends from the southwest corner to the northeast center of the property. Maple Valley Road (SR169)borders the south edge of the AnMarCo property and the south edge of the western portion of the Segale parcel. Widening of this road in 1971/72 resulted in excavation of discontinuous cut slopes along the base of the bluff slope. A similar excavated slope exists northeast of Maple Valley Road near the west portion of the AnMarCo property; this area is used as a parking lot for Stoneway Concrete. On the AnMarCo property, sand and gravel has been removed since about 1960 by truck export. The trucks entered and exited Northeast Third Street north of the site. Prior to 1960, sand and gravel was transported by means of a conveyor system down the steep bluff, across Maple Valley Road and to a concrete production plant within the Stoneway Concrete operation. A much larger volume of sand and gravel has been mined from the Segale property than from the AnMarCo land. Most of the mined material from the Segale property was hauled by trucks exiting north to Northeast Third Street. Between 1978 and 1981, some sand and gravel was mined from the southern portion of the Segale property by pushing the soil over the south bluff utilizing large bulldozers. A relatively minor amount of excavation of the bluff face also occurred at that time. Three significant topographic trenches remain where material was pushed over the bluff utilizing large bulldozers. The bluff crest was also lowered in the immediate area in which that activity occurred. TOPOGRAPHY AND VEGETATION The existing top of bluff location was surveyed in the field by Boyd and Associates as noted above. The criteria for determination of this alignment is visual and not based on slope declivity since the crest is very obvious throughout its length. The bluff along the south edge of the AnMarCo property varies from about 175 to 270 feet in height. The top of bluff ranges from a maximum of Elevation 330 feet near the southeast upland corner to about Elevation 230 feet at the northwest extreme of the AnMarCo property. The base of the bluff is near or adjacent to Maple Valley Road at about Elevation 55 feet. Declivity of the bluff on the AnMarCo property ranges from about 75 to 100 percent inclination. A near-vertical cut slope approximately 10 to 30 feet in height is located along the margin of an excavated parking lot adjacent to Maple Valley Road. Other isolated cut slopes adjacent to Maple Valley Road range in height to about 30 feet and are excavated at an inclination of about .75H to 1V (horizontal to vertical), or 135 percent. G e o E n g i n e e r s File No.0171-031-R02/3473-001-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 5 The southeast portion of the top of bluff on the AnMarCo property forms the head of a broad, rounded gully. The gully is about 600 feet across and about 100 feet deep relative to the adjacent bluff crest. The remainder of the top of bluff on the AnMarCo property is relatively straight, except for an excavated slot where sand and gravel was fed to the conveyor system, as mentioned previously. Vegetation is well established along the entire bluff slope of the AnMarCo property, except for the cut slopes at the parking area and along Maple Valley Road, as described above. The vegetation consists of deciduous and coniferous trees, most of which are quite large. The conifers are commonly about 2 feet dbh (diameter at breast height). The larger deciduous trees are typically maples and alders that are at least 2 feet dbh. Smaller maples and alders are scattered throughout the slope. Ground cover consists of low brush and blackberry vines. In general, the conifer tree trunks are erect and straight, which is characteristic of conifers. A few trees exhibit modest "butt bows," which demonstrate slight movement of surficial soils as is expected on steep slopes. The deciduous trees are commonly leaning, but do not exhibit chaotic disorientation that would imply unstable slope conditions. The top of bluff on the Segale property consists of three relatively distinct segments, west, center and east, as shown in Figure 2. The west segment is about 400 feet in length and extends from the southwest Segale property corner to the west edge of the powerline right-of-way. The center segment extends from the east edge of the powerline right-of-way for about 2,000 feet east. The east segment is about 600 feet long and is adjacent to a large ravine, or gully, which extends from the upland to a terrace adjacent to the Maplewood subdivision on the Cedar River floodplain. In the west segment of the Segale property, the bluff is about 250 feet high, extending from Maple Valley Road at about Elevation 60 feet to the crest at Elevation 310 feet. Declivity of the bluff slope in this segment averages about 50 percent. Locally, the slope is somewhat steeper and the extreme base of this slope is truncated by an excavation created during widening of Maple Valley Road. The top of bluff at this segment forms the head of a gully that is similar to but much smaller than the larger gully on the AnMarCo property, as described previously. Vegetation on this segment of the Segale property is similar to that on the AnMarCo property, as described above. In the center segment of the Segale property, the base of the bluff occurs at about Elevation 70 feet to 100 feet, which is about 10 to 40 feet above the elevation of the adjacent Cedar River valley floor. The higher ground surface at the base of the bluff is the result of natural processes wherein material weathered or failed from the bluff has accumulated along the toe, together with an accumulation of soil from past mining activities. The top of bluff ranges from about Elevation 320 feet near the powerline right-of-way to a low point of Elevation 210 feet near the middle of the center segment, then rises to about Elevation 280 feet at the common boundary between the center and east segment. G e o E n g i nee r s File No.0171-031-R02/3473-001-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 6 The bluff slope declivity in the center segment averages significantly steeper than 100 percent, except at the extreme east edge of the segment. The western 700 to 800 feet of bluff in this segment is nearly vertical for heights ranging from about 10 feet to more than 40 feet. In isolated locations, comprising only a small portion of bluff, the crest is actually overhanging where a vegetation root mat is undermined by surficial weathering of soils on the bluff face. The top of bluff alignment forms a relatively smooth curve that is locally interrupted by bulldozer-cut slots excavated during the mining activity between 1978 and 1981. Comparison of the top of bluff elevation based on recent survey with topographic maps prepared in 1962 indicates the top of bluff has been lowered by mining by 50 to about 75 feet near the middle portion of the center segment. The presence and type of vegetation along the center segment of the Segale property is variable. Where mining activity directly disturbed the bluff face slope and where slope declivity is less than approximately 100 percent, vegetation consists of alder saplings 1 inch to 6 inches in diameter, and mixed brush and blackberry vines. Where the excavated or disturbed slope face is extremely steep, it is devoid of vegetation. In areas where mining did not directly disturb the slope, vegetation consists primarily of large deciduous and coniferous trees with low-growth ground cover of brush. The east segment of the Segale property adjoins a relatively large ravine that extends from the upland at about Elevation 300 feet to the terrace surface above the Cedar River valley floor at about Elevation 100 feet. Slope declivity in this segment ranges from about 45 to 80 percent at the higher elevation and flattens considerably toward the base. Vegetation on the bluff slope in the east segment consists of coniferous and deciduous trees ranging from less than 1 foot dbh to more than 4 feet dbh. The understory consists of dense brush and small trees. The trees are erect to slightly "butt bowed." We noted no evidence that suggests large-scale landslides have occurred in historical time. A primitive road traverses from the upland to the valley floor across the steep slope face from about the center of the east segment to the eastern portion of the Segale center segment. A sanitary sewer line descends the steep slope face roughly along the axis of the ravine. SURFACE AND GROUND WATER DRAINAGE We noted no evidence of significant surface water flow on the bluff face within either the AnMarCo or Segale properties. Minor localized surface flow occurs as the result of direct precipitation on the slope, especially within local topographic drainages. Also, we observed evidence of minor surface flow, again resulting only from direct precipitation, in the bulldozer slots located near the middle of the Segale center segment and to a minor degree in the lower ravine of the Segale east segment. We observed evidence of possible ground water seepage only at two widely separated locations along the bluff. The seepage areas are a few feet in height and G e o E n g i nee r s File No.0171-031-R02/3473-0O1-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 7 50 to 100 feet long. No free-flowing surface discharge water was observed. One location is about mid-slope near the south-central portion of the AnMarCo property, the other is low in the ravine adjacent to the east edge of the Segale property. Test borings by others in the upland area show the top of the low-permeability soils typically occurs at lower elevations than in the bluff face. This suggests that the dominant ground water flow direction in the development area is northward, away from the bluff, and explains why there is little emergence of seepage along the bluff. GEOLOGY At this site, the visible geologic materials include Tertiary bedrock at the base of the bluff, and overlying Pleistocene glacial and interglacial soils. The modern Cedar River valley was eroded after the last glacial ice disappeared from this area. The alluvium that underlies the valley floor is relatively recent. Several episodes of regional glaciation have occurred in the Puget Sound basin. The ice advances were separated by periods in which climatic conditions were similar to modern conditions. Each ice advance was accompanied by deposition and erosion, both directly by the ice and by streams that discharged from the advancing and retreating ice front. The glaciers reached a maximum thickness of several thousand feet in this area and each ice advance thoroughly consolidated the previous glacial and interglacial sediments. At the project site at least two glacial episodes are represented by exposed soils and in various test borings. The most recent advance is called the Vashon glaciation; this glacial ice disappeared from this area about 13,500 years ago. The Vashon glacier, post-glacial erosion and deposition, and recent mining are responsible for the dominant features of the present topography in the project area. The steep bluff along the south edge of the development area is formed primarily in pre-Vashon deposits consisting of very dense interbedded gravelly sand and sandy silt. The proposed development area and the surrounding upland surface are directly underlain by loose to dense sand and gravel outwash deposited by streams flowing from the melting Vashon ice. It is this outwash material that was previously mined at the site. After disappearance of the Vashon ice the Cedar River valley was eroded rapidly to well below modern sea level. The rapid down-cutting over-steepened portions of the valley wall and resulted in some massive landslides. Unstable slopes exist today where the modern river is under-cutting the valley walls. At the project site, this river is diverted well away from the valley wall by SR169. At the project site active slope retreat processes include only surficial mechanisms. These occur as soil creep in the forested areas and as thin surficial soil falls, debris avalanches and direct rainfall erosion in devegetated, over-steepened locations. We observed no evidence of deep seated block or slump failures on the development site. A discussion of bluff crest retreat rates is presented in the following section. G e o E n g i n e e r s File No.0171-031-R02/3473-001-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 8 CONCLUSIONS GENERAL In our opinion, the proposed 25-foot building setback from the top of slope along the bluff is satisfactory except as noted below. We recommend that a setback of at least 40 feet be planned where fill placement is anticipated to raise the building site elevations, and adjacent to portions of the bluff that are precipitous and unvegetated. The locations where we recommend a 40-foot setback are shown in Figure 2. Where the bluff slope is covered with vegetation, we estimate the rate of crest retreat to be less than about 1.0 foot per decade. Where devegetated, the crest retreat rate will be about one foot to five feet per decade until the slope is flat enough to support a well-developed vegetative cover. Normally this process takes about 30 to 50 years if left strictly to "natural" means and where the toe of slope is not being actively eroded or excavated, after which the retreat rate slows to less than one foot per decade. Our estimate of the retreat rates is based on the performance of literally hundreds of miles of river, lake, and marine shoreline throughout the Puget Sound basin. FUTURE SLOPE STABILITY We expect future bluff crest retreat to occur by processes similar to those now in evidence. We expect that minor, discontinuous, episodic surficial failures could occur at any location along the bluff crest. These will generally be related to extreme storm events or to uncontrolled releases of surface water over the bluff crest. The type of failures expected will typically be a few feet to a few tens of feet in length and 1 to 5 feet thick measured perpendicular to the slope face. We do not expect deep seated block or slump failures to occur. Our computer analyses of the bluff stability indicates a factor of safety against any failure which could displace a zone of soil more than 25 feet thick to be 1.5 or greater. This meets or exceeds the factor of safety recommended by the Unified Building Code for "critical facilities" such as hospitals or schools. We recommend that any fill placed to raise building pads along the bluff be placed as structural fill. The fill must be keyed into undisturbed dense native soils and the outboard slope of the embankment should be no steeper than about 2H:1V. Erosion protection must be provided. These recommendations are not intended to be design recommendations, but are assumed in our evaluation. Detailed, specific engineering design of the fill could result in a slope face steeper than used in our evaluation and a reduction of the recommended setback. G e o E n g i n e e r s File No.0171-031-R02/3473-0O1-R02 M.A. Segale, Inc. AnMarCo March 7, 1994 Page 9 LIMITATIONS We have prepared this report for M.A. Segale, Inc. and AnMarCo for their use in planning this project. Our evaluation is preliminary in nature because the exact details of the project are unknown at this time. As the design develops, we recommend that the details be reviewed by our firm to see that our evaluation has been incorporated as intended. Within the limitations of scope, s'::'.:edule and budget, our services have been accomplished in accordance with generally accepted practices in this are at this time. If you have any questions about our report or if we can provide additional services, please call. Yours very truly, GeoEngineers, Inc. Jon W. Koloski Principal JWK:cros Document ID: 0171031.R Attachments Two copies submitted cc: Mr. David Halinen Halinen & Associates 10500 N.E. 8th Street, Suite 1900 Bellevue, WA 98004 GeoEngineers File No.0171-031-R02/3473-001-R02 REFERENCES Boyd and Associates, Inc., December, 1993, Top of bank location, Edwards Pit, Renton, Washington, for M.A. Segale, Inc., survey: scale 1:1,2000. Boyd and Associates, Inc., December, 1993, Top of bank location, Stoneway property, Renton, Washington, for AnMarCo, survey: scale 1:1,200. GeoEngineers, Inc., April 16, 1986, Supplemental report, Edwards Pit hydrology and reclamation, Renton, Washington, for Metro Sand and Gravel, Inc. GeoEngineers, Inc., February 6, 1981, Report of consultation, Edwards Pit hydrology, Renton, Washington, for M.A. Segale, Inc. Golder Associates, Inc., October 19, 1993, Report to RH2 Engineering, P.S., Geotechnical engineering study for east Renton interceptor, city of Renton, Washington. Golder Associates, Inc., January 11, 1988, Report to Centron, Preliminary hydrogeologic- geotechnical study, McMahon property, Renton, Washington. Mullineaux, D. R., 1965, Geologic map of the Renton quadrangle, King County,Washington: U.S. Geological Survey Map GQ-405: scale 1:24,000. Topographic maps, city of Renton, Sections 16 and 17, Township 23 North, Range 5 East, Willamette Meridian: scale 1:2,400, based on aerial survey of 1962. Topographic map, Segale property, undated, untitled: scale 1:1,200, provided by M.A. Segale, Inc. U.S. Geological Survey, 1949, photorevised 1968 and 1973, Renton quadrangle, topographic quadrangle map: scale 1:24,000. Walker and Associates, Inc., Aerial photographs of the site for the years 1936, 1946, 1968 and 1985. GeoEngineers File No.0171-031-R02/3473-001-R02 7 t -„„ --- 1--;-. .,- 4 __ I-.. L..,--/:„:\- 1 ,...-..: 1 vi • ,::----,-,: 7,- 7,--: 6..', , :, i c r.. i 1,,. /...;". - 11 . i.. '' d ,, - ca,.... 1 ._ 77-11 , 4.-- i:------- 4----------":-'. ----".. 7 =;•- i.,-. il' '. 11'1',1 dr. i:....••••• v4.-- 11 t- .• - f.,..; F:_ or.- 7...--.,..:•••'_ ...... i; Irit- nu . Pi& 7 AMIIi/ INIIII' ''''''.." 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ANMARc o M.A. SEGALEA2SoPgoI'Y 12 oFF_RTY So 300 7A) " '74'g. •- h?"1.„_,,f::_;Ssc, 1( (i.7.. \/- ,..4 1ckN-\\. Ni.. A 11 o 5‹2 i 'a-; t 4 1•-!(- ^.ii, t. e..-- I--C -2-513<c) 26,.,..- N, .`-L :.ti.f'4wi --,%;'.•••yam. 0 V 2S• y::v`7i-'-tip 'i.t ., "if is y..: ^i,,'Z;:'L t! ; x 330 a =H,::: i ,. ':i v 2uo ,t90 rT ITN 2-10 WO SG 111r..i Z 1. , e ft...,..F. ti R O o..;y . t>- t •A Yet, 4: ,, j71 f?" 1 1 = •'' i ".''.2.1 0 -x?S k ry{a- 13 A Y' aT S--x tic:1•-•.7 :Xi 69 < t' = s+ -",3 1 o sn f; i ,a 1. S ' t;.Y ' x 1-.4“. !':`•%:Y; ", '.. ' , 4 .,-.;., ,,--N .,t;I: -,.., 9, . fir :, 1i ', X 7c. µill1 t' I yt,i Y i;, D I 5 STN 5T K E ET cDA i j ,511E PLAN G eo 0 L1]gineers FIGURE 2 PRELIMINARY GEOTECHNICAL REPORT McMAHON PROPERTY ROAD ALIGNMENT Prepared For CENTRON This report was prepared under the supervision of a registered professional engineer cam~ , b y 17706 r ry • CH2M HILL 3•••eCJ StC) ay 1988 SEA24614.B0 seOS6604/001/1 CONTENTS Page Introduction 1 Project Description 1 Site Description 1 Site Geology 2 Field Exploration 3 Subsurface Conditions 4 Results of Laboratory Testing 6 Stability Analyses 6 Cut Slope 6 Fill Slope 7 Discussion 8 Additional Recommended Geotechnical Exploration and Analyses 10 References 10 Appendix A. Results of Laboratory Testing Appendix B. Logs of Test Borings G Q M se0S6604/003/1 TABLES Page 1 Water Level Readings 5 2 Direct Shear Test Results for Lacustrine Silt 7 FIGURES 1 Geologic Map At end 2a Schematic Geologic Profile, Station 13+00 At end 2b Schematic Geologic Profile, Station 16+00 At end 2c Schematic Geologic Profile, Station 25+00 At end 2d Schematic Geologic Profile, Section Between Borings At end 3 Static Condition, Cut Slope Stability, Slope Configuration At end 4 Static Condition, Cut Slope Stability, Analysis Results At end 5 Static Condition, Fill Slope Stability, Slope Configuration and Analysis Results At end se0S6604/003/2 INTRODUCTION The purpose of the geotechnical exploration program is to provide a preliminary assessment of existing site conditions with respect to stratigraphy, groundwater conditions, soil conditions , and geotechnical parameters and to obtain sub- surface samples for laboratory testing to provide a better understanding of existing conditions for the proposed road alignment. The scope of work for the geotechnical exploration includes : o Site reconnaissance and mapping o Field subsurface exploration o Laboratory testing of selected samples o Geotechnical analysis and preparation of this report PROJECT DESCRIPTION The proposed road is approximately 2, 200 feet in length and w:.11 connect the McMahon property with the Maple Valley H:..ghway, providing major access to the developing area of southeast Renton, north of the Maple Valley Highway. The road is proposed to be a four-lane road with a fifth lane for left turns where required. Initial development will l:.kely be a two- to three-lane section. Because of the steep grade of the existing slope, the pro- posed road grade will vary from 8.5 to 12 percent. Eleva- t: on gain along the road is approximately 200 feet. The proposed road alignment is primarily in cut. SITE DESCRIPTION Tie property at the upslope end of the McMahon road align- ment will connect to an area where, in the past, sand and gravel have been mined. It appears the resource is near the erd of its commercial life, as most of the desirable mate- rial has been removed. The proposed road alignment traverses a very steep area. Existing slopes range from near-vertical cuts near the top of slope and flatten to about 29 to 35 degrees in the middle and bottom of the slope. The vegetation consists primarily of blackberry, ferns , alders, occasional firs and cedars, and horsetails where the ground is wet at the surface. Many se0S6604/002/1 1 springs and wet areas were noted during the field reconnais- sance and are shown in Figure 1. the previous owner dammed a spring area to provide a water source for livestock and maintained a one-lane gravel road up the hillside in the approximate location of the proposed road. A ditch on the upsiope side of the road was used to divert water from the roadway. This road fell into disuse and is now only a trail. Parts of the old road have been lost as a result of slope movements. Areas at the top of the slope facing the Maple Valley High- way have been modified as a result of quarry operations. At one time, sand and gravel were removed from the southern portion of the pit by cutting a notch in the top of the h.illslope and dumping the material down the slope for load- ing out at the base. Significant erosion has occurred along portions of the old roadway particularly near its lower end. The soil is ex- tremely erodable and has resulted in the construction of containment dikes , ponds , and other stabilization measures . It is our understanding that significant cleanup operations were required to remove soil that was deposited on the Maple Valley Highway. This occurrence resulted from the uncon- trolled release of impounded water within the pit area through the previously described notch cut at the top of the slope. SITE GEOLOGY Figure 1 is a geologic map of the site showing field obser- vation site slide zones and seeps. Geologic mapping was restricted to the slope and surrounding area accessible along the existing trail. Because much of the exposed ma- terial appears to have been displaced by landslides, it is s;)eculative to map the soil deposits from these exposures. Material types present in slope exposures along the trail vp!re primarily fine grained. Geologic cross sections are s'.aown in Figures 2a through 2d to illustrate schematically s'zbsurface conditions near the slope surface. The hillside i capped by a 5- to 20-foot layer of sandy gravel. The sand gravel is underlain by glacial till from location A to B, as shown in Figure 1. The till consists of silt to sandy silt with localized pods or thin layers of clay. Approximately 20 to 40 percent of the till consisted of sub- rounded gravel about 4 inch minus in size. Water seeps were present in the till layer. Underlying the till from loca- tion B to C is massive to thinly bedded silt to a very fine sand, a glaciolacustrine deposit. From locations C to D, slIOS6604/002/2 2 there appears to be a highly distorted outwash unit con- sisting of weakly cemented sand and gravel. Further to the west from location E, till is present in the hillside above the road alignment to an approximate elevation of 200 feet. Sand was present above the till in this area. Seeps were noticeable at the contact of the till and sand. The area below the top of the till was consistently wet. Evidence of fairly recent slope movement is found along the proposed road alignment and in the cut face of the quarry along the base of the hill. The evidence includes tension cracks, hummocky topography, bowed tree trunks, and dead trees that have been cut off at the roots by slope movement. The lateral and vertical extent of the slides are unknown at this time, but they may be 10 to 30 feet thick. The slides appear to be translated blocks of the fine- grained soils and flows of the overlying sandier materials . In a publication on slope stability in central King County Miller, 1973) , the slope where the proposed road is located is classified as potentially unstable and prone to movement. The area to the south of the initial portion of the proposed road alignment has been mapped as manmade fill. East and north of the area below the proposed road alignment as shown in Figure 1 is a large wet area that has been mapped as col- luvium or old landslide debris (Mullineaux, 1965) . The geology of the gravel pit above and north of the road alignment has been mapped by Golder Associates (1987) . The material being mined consists of outwash sand and gravel. The gravel overlies the sand and is weakly cemented and stands near vertical in cuts. The underlying sand is fine grained. The outwash is underlain by a glaciolacustrine unit consisting of thinly bedded silt with minor fine sand and occasional rounded gravel. Till has been mapped further to the east outside the active mining area and, as previously mentioned, was also encountered along the hillside trail in this area. FIELD EXPLORATION The field exploration was conducted in two phases. The first phase consisted of a 1-day geologic mapping effort of the materials exposed in cuts that could be reached from the existing trail that traversed the slope. The geologic map- ping was conducted on January 22, 1988. The second phase of the field exploration consisted of two test borings conducted from February 22 to 29, 1988. The test borings were drilled by Kenner Drilling, Inc. , of Sher- wood, Oregon, with a CME-75 mud rotary rig and ranged in depth from 150 to 185 feet. . Disturbed samples were obtained se0S6604/002/3 3 using two types of split-spoon samplers. From the ground strface to depths of about 60 feet, standard penetration tests were performed with a 2-inch-O.D. split-spoon sampler driven with a 140-pound hammer falling 30 inches. For depths in excess of 60 feet or in materials with a high per- centage of gravel, a 3-inch-I.D. split-spoon sampler driven with a 300-pound hammer falling 30 inches was used to take the samples. Undisturbed samples were obtained using two methods. In softer materials, undisturbed samples were ob- tained in 3-inch-diameter, 30-inch-long steel tubes that are pLshed 24 inches into the soil in one continuous stroke with the hydraulic head of the drill rig. In harder materials, urdisturbed samples were obtained with a Pitcher sampler, which consists of a 3-inch-diameter, 36-inch-long steel tube that is connected to a rotating outer barrel and bit that advances to obtain the sample. Samples were visually clas- sified in the field according to the Unified Soil Classifi- cation System by CH2M HILL geotechnical personnel. Field bcring logs were revised as necessary based on the results of laboratory testing. SUBSURFACE CONDITIONS Tr.e description of subsurface conditions is based on a field e>ploration program that includes two test borings shown on Figure 1 combined with observations from the geologic map- ping. Figure 2d is an interpretation of subsurface condi- tions between test borings B-1 and B-2. Test boring B-i is located south of the existing gravel pit at an approximate elevation of 244 feet. The test boring was located in hummocky topography, possibly caused by the movement of saturated sand. The area has revegetated, but movement may still be occurring at a slow rate, as the aLders growing in the sand appear to be dying. Test boring B-1 was drilled at a surface elevation of 244 feet to a depth of 150 feet. Two units were present in the test boring. The upper 15 feet is medium- to fine- grained poorly graded sand, brown, moist to wet, with occa- s:.onal 1-1/2-inch-minus gravel. The sand is medium dense to dense and appears to be an outwash deposit. Underlying the sand is more than 135 feet of silt to sandy silt that is g: ay, wet, and hard with fine sand partings and varies from thinly laminated to massive. The silt is a glaciolacustrine deposit. The second test boring was drilled east of test boring B-i a.: elevation 282. Five subsurface units were encountered. The upper 9 feet consisted of poorly graded gravel and con- s:Lsted of 1-1/2-inch-minus broken and angular rock that was wet and very dense on the basis of blow counts. However, it sOS6604/002/4 4 is unlikely material blow counts are a true indication of 3ensity as the sampler was bouncing on large gravel and the gravels appeared to collapse as the hole progressed. Test boring B-2 was relocated four times before successfully pen- etrating the gravels. Below the gravel is 14 feet of firm to stiff, lean to fat clay with interbedded lenses of sandy silt and sandy clay. The third unit is 57 feet of till con- sisting of sand, gravelly sand, and silty gravel. The till is gray-brown, moist to wet, and very dense. The upper 10 feet is weathered. The fourth unit is 24 feet of till interbedded with silt. The fifth unit is more than 90 feet of silt. The silt is gray, moist to wet, hard, with occasional thin silty-fine sand layers up to 1-1/2 inches thick. Ten-foot intervals of the ,silt unit in borings B-1 and B-2 were gravel packed and sealed top and bottom to measure water pressure within the silt. Water level readings are presented in Table 1 . Table 1 WATER LEVEL READINGS Water Level Elevation Test Depth Elevation Gravel Pack Loring Date feet) feet) feet) B-1 3-08-88 131 . 3a 163. 4 to 94 . 0 3-14-88 135 . 4 108. 6 B-2 3-08-88 172 . 3 109. 7 Approx. 172 to 97 3-14-88 174. 4 106. 7 Water level probe stuck at a depth of 131. 3 ft with no water level recorded. These water levels, the apparently saturated soil samples, and the surface seeps at higher elevations than the test hole water levels suggest the presence of a series of perched groundwater zones beneath the slope. f e0S6604/002/5 5 RESULTS OF LABORATORY TESTING Laboratory testing was performed on selected soil samples to classify the subsurface units and to evaluate their engi- reering properties. Laboratory tests include natural mois- ture content, hydrometer grain-size analyses, and direct shear tests. The laboratory testing was performed in accor- dance with applicable ASTM standards. The results of nat- ural moisture contents are presented in Table A-1 in the appendix. Grain-size analysis curves and plots of the direct shear tests are also presented in the appendix. Strength data from the direct shear tests were developed for use in the stability analysis. The hydrometer testing con- firms that the glaciolacustrine unit is mainly silt with 10 to 23 percent clay and 3 to 4 percent sand. Moisture contents were performed on selected samples from the test borings . Based on our knowledge of similar mate- rials in this area, it appears that the samples tested are at or above optimum moisture content for compaction. STABILITY ANALYSES Stability analyses were performed for the proposed two hori- zontal (H) : 1 vertical (V) cut and fill slopes for the new roadway. The analyses were performed for the static loading case and for two seismic cases using "pseudo-static" anal- yses. All the analyses were performed using the computer program PCSTABL5. The slope geometries , material properties, and groundwater level assumptions for the analyses are shown in Figure 3 for cut slopes and Figure 5 for fill slopes. The analyses for tie proposed cut and fill slopes are described below. Cit Slope Figure 3 shows the proposed 2H: 1V cut slope at Station 16+00 near boring B-1. Boring B-i indicates that the lacustrine silt and sandy silt deposits comprise the majority of the slope material at this location. The results of the the direct shear tests performed on samples of the silt are listed in Table 2. For the cut slope stability analyses, an effective stress cohesion intercepts ranging from zero to 6)0 pounds per square foot was used. seOS6604/002/6 6 Table 2 DIRECT SHEAR TEST RESULTS FOR LACUSTRINE SILT Effective Peak Strength Parameters Friction Cohesive Depth Angle Intercept Boring Sample feet) . USCSa (degrees) psf) B1 PT16 83 ML 36 300 B2B S26 180 ML 29 600 aUnified Soil Classification System. Three trial piezometric surfaces labelled A, B, and C in Figure 3 were used in multiple runs of the stability anal- yses to bracket the probable range of water pressures acting on the cut slopes. The results of the stability analyses are summarized in Fig- ure 4. A factor of safety (ratio of resisting forces to mobilizing forces) of at least 1.5 is customary for the static case (earthquake acceleration = 0 .Og) for design of new construction. As shown in Figure 4, a safety factor of 1.5 only occurs for a low groundwater level (piezometric surface A) and only when the cohesion intercept is at least 500 pounds per square foot. The risk of slope failure in- creases with higher groundwater levels, decreasing cohesion, or both. A seismic analysis of the same slope was performed assuming the soil response to ground shaking resulted in an undrained condition. In the absence of laboratory data, an undrained shear strength of the silt of 3, 000 psf was assumed. The analyses determines the yield acceleration of the embank- ment, or the acceleration at which the safety factor is 1. 0. The yield acceleration is estimated to be 0.07 g. Because recommended design acceleration values for embankments are commonly 0. 12 to 0. 15 g, this estimate suggests a higher- than-average risk of earthquake damage on this slope. Labo- ratory testing is required to adequately define this risk. Fill Slope Figure 5 shows a proposed 2H: 1V fill slope at Station 24+00, which is at the location of a mapped active landslide. Based on our reconnaissance, the depth of movement probably is about 30 feet below the slope surface, as shown in Figure 5. se0S6604/002/7 7 Figure 5 shows boring B-2 soils and groundwater level infor- mation and an estimated landslide failure surface. A stability analysis shows a factor of safety of 1. 0, confirm- ing the geometry and soil properties. Stability analyses for the proposed 2H: 1V fill slope were performed using the same existing slope conditions with the addition of fill. A safety factor of 1.52 resulted for the static case. This safety factor is ordinarily considered adequate for new construction without seismic loading. DISCUSSION The stability analyses should be considered preliminary be- cause the soil conditions are complex, the soils information limited, and conditions are not yet well understood. Addi- tional borings with instrumentation (piezometers, slope inclinometer casings) and additional laboratory tests are necessary to perform a complete investigation for the pro- posed road construction. The preliminary stability analyses indicate that the pro- posed 2H: 1V cut slopes provide adequate safety factors under static conditions only if the_piezometric _water_levels in the _ slope are relatively 1ow._and theslope_soi,ls__exhbit some cohesive strength. There is a good chance that these favorable conditions are present but additional investiga- l tion is required to verify this opinion. For design seismic% conditions , some slope yielding and deformation are expected. More data are required to develop a specific prediction of dope movement. he preliminary stability analyses also indicate that the proposed 2H: 1V fill slopes provide adequate safety factors for static conditions . However, this conclusion depends on an assumed depth to the failure surface. The actual depth hould be determined by the recommended additional work for final design. As with the cut slope, for design seismic conditions the fill slope can be expected to experience some permanent deformation. Urainage of water is extremely important in order to reduce the potential instability of slopes, provide a more economic design, and reduce the maintenance and erosion of soil caused by surface water on the slopes. Measures that can be taken to reduce the amount of surface infiltration on the slope and at the top of the hill will reduce the magnitude of this problem; however, they will not eliminate the prob- lem. Drainage blankets, trenches, and collection piping will be required to reduce the problems associated with areas of spring fed seepage exiting on the slopes. Con- trolling the piezometric water surface within the hillslope will reduce the potential of sliding and instability. se0S6604/002/8 8 Approximately 80 percent of the contact between fill and natural soils should have a drainage system comprised of chimney drains and collection pipes. The chimney collection drains will require use of very clean sand or gravel or the use of artificial drainage fabrics. The excavated soils will not meet these requirements. An additional concern is the erodible nature of the silt encountered in the test borings and present in the slide material noted in the geologic reconnaissance. Because of the long cuts anticipated in this material, immediate pro- tection of the exposed slope will be required. The protec- tive measures may include jute mat coverings and seeding of all exposed cut slopes. Benches may be required along the slopes at slope distances 100 to 200 feet to divert drainage and to allow equipment access for maintenance such as clean- ing drainages, repairing eroded areas, placing drain mate- rials on slopes, installing piping, seeding of slopes, or other such purposes . Erosion control on the sideslopes should require use of such measures as ground mat cover and planting, benches , silt fences , gravel drains, collection pipes and ditches , or siltation ponds. The slopes will re- quire periodic maintenance and cleanup, especially until new vegetation becomes well established. The maintenance access should be sufficient to allow access for trucks and excava- tion equipment for cleanup of sloughed or eroded debris that collects at the base of the slopes. The final alignment should be selected to minimize long, thin cuts and fills that only remove the existing surface mat of vegetation. Removing the vegetation only aggravates the erosion problem and does little to improve the slope stability. Retaining walls may be of economic benefit in certain areas , if needed to limit the removal of natural vegetation. Construction sequencing must be performed to minimize sta- bility concerns. The excavation should begin at the top of the slope to maintain hillslope stability and to facilitate handling and disposal of excavated material. The construction of the proposed road will require a sub- stantial amount of excavation. A preliminary alignment has been chosen to limit the volume to 700,000 to 1,000,000 cubic yards of earth excavation. The excavation material is pre- dominantly fine grained and presently exists at or slightly above the optimum moisture content of the material for re- compaction. Because the material is so fine grained, it will be very water sensitive and difficult to work with dur- ing wet-weather periods; therefore, its suitability for use • as fill material is very limited. The material can be placed and compacted to adequate densities if the natural moisture content at the time of placement is at or below the se0S6604/002/9 9 optimum moisture content. It may be uneconomical to obtain this moisture control. Disposal areas should be designated where compaction is not critical for placement of higher moisture content materials. ADDITIONAL RECOMMENDED GEOTECHNICAL EXPLORATION AND ANALYSES Irior to final design, additional field and laboratory test- ing must be completed to further define the subsurface soil and groundwater conditions. The field work should include enough test borings along the road centerline and above the roadway to have a final borehole spacing of 200 to 300 feet. Zhe borings should be completed as piezometers and/or with slope inclinometer casings . The piezometers should better define the variation of groundwater levels within the slope along the road alignment. The slope inclinometer casings permit periodic monitoring of the slope movement. The depth cf the slide surface of the major slide areas should be determined from this investigation. Soil samples obtained from the test borings should be tested to evaluate their engineering characteristics and strength parameters . With the data obtained from the 'additional field and laboratory work, additional stability analysis should be performed on the proposed road design configura- tion. This information should be summarized in a final geo- technical report incorporating an assessment of a design earthquake acceleration for the site and geotechnical design recommendations for construction. REFERENCES Miller, R.D. 1973. Map showing relative slope stability in Part of west-central Ring County, Washington. U.S. Geologi- cal Survey, Miscellaneous Geologic Investigations Map I-852-A, Scale 1: 48, 000. Mullineaux, D.R. 1965. Geologic Map of the Renton Quad- rangle. U.S. Geological Survey Map GQ-405. se0S6604/002/10 10 1 300— Outwash Poorly Graded Sand) Massive Sliding In This Unit LL 200— 1----- Seeps Present at Till/Outwash Contact o TIllII and Locally Along Till Exposures m w 100- Man—made Fill 0- 0 2 3 4 5 6 7 g Distance x 100 Feet STATION 13 + 00 Scale: 1' - 80' H & V I Notes: 1. See Figure 1 for location of geologic profile. 2. Refer to accompanying test for complete description of geologic units. 3.The depth end thickness of the subsurface strata Indicated on the geologic profiles were generalized from end Interpolated between test borings and geologic outcrops. Information on actual subsurface conditions exists only at the specific locations Indicated. Soil conditions and water levels at other locations may differ from Figure 2A conditions occuring at the boring locations. Also, the passage of time may result In a change In the conditions at these boring locations. SCHEMATIC GEOLOGIC PROFILE III 300- Outwash B_1 Poorly Graded Sand) 200- m ii Glaciolacustrine Deposits (Silt) Outwash o m L W 100- 3-14-88 7` Man-made Fill 1 0- 0 1 2 3 4 5 6 7 Distance x 100 Feet STATION 16 + 00 Scale: 1' - 80' H & V See Figure 2A for Notes Accompanying this Figure. Figure 2B 111/1 SCHEMATIC GEOLOGIC PROFILE L:L:I;u11 Loose Gravel 300- B-2 1—1 Lean to Fat Clay 7 TIII Interbedded Till 1ii1ii1andGlaclolacustrine 200- Deposits 1 " LL_ Glaclolacustrine Deposits 0 w 100- 3-14-88 ? 7 7 Cedar River Floodplain and p i Old Coliuvium/Landslide Debris Wet Area 0- 1 2 3 a 5 6 7 Distance x 100 Feet STATION 25 + 00 Scale: 1' - 80' H & V See Figure 2A for Notes Accompanying this Figure. Figure 2C 11111111/11 SCHEMATIC GEOLOGIC PROFILE [7Tlp1 NOM 300- B-2Gravel 7 1- B-1 Till Outwash 9 200 L •Interbedded TIII and ?Glaclolacustrine Deposits m T — LL Glaciolacustrine Deposits (Silt) 0 i0 m Q w 100-3-14-88 0- O 1 2 3 4 5 6 7 8 Distance x 100 Feet SECTION BETWEEN BORINGS Scale: 1' - 80' H & V See Figure 2A for Notes Accompanying this Figure. Figure 2D MEM SCHEMATIC GEOLOGIC PROFILE J 11111/MMI 300- B-1 Projected Trial Piezometric 50' West Surfaces Sand (Out-washi C Elev 210'2 Slit 200- 1 1---- i` - s ( Glacio- lacustrine B Elev 160' Elev (ft) Deposits) I v A Elev 110' 100- 3-14-88) Assumed Material Properties: moist - 118 pcf, Y sat - 122 pcf, 0- 0 ' C 600pst, 0 - 30° SECTION AT STA. 16 + 00 Scale : 1' = 100' H & V Notes: 1. This section used for stability analysis of the proposed 2H:1V cut slopes. Figure 3 2. See the log of boring 8-1 for a more complete STATIC CONDITIONdescriptionofthematerials & conditions encountered. CUT SLOPE STABILITY SLOPE CONFIGURATION 2 1 C Factor of Safety 1 0 500 1000 Cohesion Intercept (psf) Notes: 1. See Figure 3 for analysis assumptions. 2. The letters A, B & C refer to different trial piezometric surfaces shown on Figure 1. Figure 4 STATIC CONDITION MEM CUT SLOPE STABLITY ANALYSIS RESULTS 111111 1 Case Safety Factor 7 moist - 132 pcf Existing Slope 1.00 7 sat - 136 pcf Proposed Fill Slope 1.52 0 - 35' c - 0 B-2 Protected Existing Ground .__— 130' West ave Surface -.Zi/ clay Fill: 'Y moist 128 pcf2 0 , Cl) Till 0 - 338 i/ E. cij Interbedded 200— c - o I/`/ N a) Q. .— TIII and Silt 0 I Slit 2 Elev 100— Proposed Slope V_/ 3-14-881( ft) Assumed Existing Assumed Failure Surface 7 moist - 118 Pcf Phreatic Surface 7 sat - 122 pcf 0 - 30° 0— c - 0 SECTION AT STA. 24 + 00 Scale: 1' = 100' H & V Notes: 1. This section used for stability analysis of the proposed fill slope Figure 5 In an area with a mapped landslide. 2. See the log of boring B-2 for a more complete description of STATIC CONDITION the materials and conditions encountered. FILL SLOPE STABILITY 3. The proposed fill slope stability analyses were performed using SLOPE CONFIGURATION MEM only the failure surface assumed for the existing slope. ANALYSIS RESULTS L!1L lllg Appendix A RESULTS OF LABORATORY TESTING se6613/012/1 Table A-1 RESULT OF MOISTURE CONTENTS Moisture Test Depth Content boring Sample feet) percent) B-1 S1 5. 0-6 . 5 17 . 3 S3 15 . 0-16 .5 15 . 1 S4 20 .0-21 .5 16 .2 iPT5 25 . 0-27.5 24 .0 S6 30 .0-31 . 5 22 .5 S8 40 .0-41 .5 21 . 8 PT9 45 . 0-48 . 0 23 . 0 S10 48 . 0-49 .5 21 .7 S12 60 . 0-61 . 5 22 . 7 S14 70 . 0-71 .5 28 .2 S15 75 . 0-76 . 5 28 . 0 PT16 80 . 0-83 . 0 26 . 1 S17 90 . 0-91 . 5 14 . 6 S19 100 . 0-101 . 3 20 . 0 S20 105 . 0-105 .9 11 . 6 S21 115 .0-116 .5 27 . 0 S22 125 . 0-126 . 0 26 . 1 PT23 135 . 0-138 18 . 9 S24 148 . 5-148 . 9 21 . 4 B-2b S1 5 .0-6 .5 5 .1 ST2 17. 0-19 . 0 37 . 0 S3 19 . 0-20 .5 41 .0 S5 30 .0-30 .9 7 . 7 S6 35 . 0-35 .5 17 . 9 S8 45 .0-45 .3 9 . 8 S10 55 . 0-55. 4 5 . 0 S11 60 . 0-60 . 9 12 . 7 S12 70 . 0-70 .9 22 .4 S14 80 . 0-80 .5 12 . 1 PT15 90 . 0-91 .0 23 .9 S16 93 . 0-94 .5 25 . 9 S17 100 .0-101 .5 24 . 3 S18 110 .0-110 .7 22 . 1 S19 120 . 0-121 .5 15 . 8 S20 130 .0-131 .5 24 . 6 S21 140. 0-140 .9 21 .9 S22 150 .0-151. 5 25 . 6 S23 160 . 0-161 .0 25 .0 S24 170 . 0-170 .5 21 . 9 S25 175 .0-175 .8 22 .0 S26 180 .0-180 .7 26 . 3 S27 185 . 0-185 .8 24 . 6 se6613/011/1 Reference ASTM 0 30b. 1,` 00 ---- -— - . x1.0 _. _- - - - -_._ . _._.._.- . p l ----- ..-- .- - •..--- x ---- . . --• W . -•- tn A to -..- QZ.° n 0-S i.o NORMAL STRESS(psf x 1000) e•5 - TEST TYPE:Consolidated/Drained Controlled PHYSICAL TEST NO. CONDITIONS A B C 0.1 `.t G.' Height(in) I. o0 0.4;5 o•Q I (- HORIZONTAL Q o.Iv Water Content(`,o) z o.3 ze.3 2fr.3DEFORMATION (in.) Void Ratio C.463 c•q11- o.i1S C - _Saturation(%)100,E tol.- q,b w - Dry Density(pcf) I o 1.1 4 E-1 q}. I z 0 - cn Time for 50% Q ___ Ul Consolidation (min) U o•c ____. ________ItW Time for 95% rn - C CC Consolidation(min.) cn 14- Void Ratio after Z -m Dry Density(pcf) j Water Content(%) zc.c , )'i.S 79.}U — a I - Z Void Ratio C.653 G,(,e(, O, lac 4lc Saturation(%>i nq.q 11 &.I 111.0p.I o•Z 0.1 Normal Stress(psf) I ill.3 23M•L IS r,c•SHORIZONTAL Maximum Shear(psf) i .'- .o 141'(1.o lc c-3•oDEFORMATION (in.) Time to Failure(min) Sample Source 13zg Su 0 - Classification Gs 7./0 C,= CmL) or 1 PLATE Applied Geotechnology Inc. Direct Shear Test Report Geotecnnical Engineering s.g: Geology d Hydrogeology CH)P^i1+4-t-/Scauarlf Wt.'We,- DRAWN APPROVED OATS REVISED DATE ttiatikoe8 IfZS c /Ye Relercnce ASTM 0 3080 3-0 L4 f O OT 1_o W pc 5 o 0.5 1.0 t.S 7.o 2.5 1.. 1.5 '14' co NORMAL STRESS(psf x 1000) 1A ai TEST TYPE:Consolidated/Drained Controlled i PHYSICAL TEST NO. CONDITIONS • A B C a1 ..Z 4,1 Height(in) o.`14S o.'1.S o•91 S HORIZONTAL Water Content(%) I..6•I 16 .1 2.c.. 1 DEFORMATION (in.) c.to Void Ratio o.815 0,191- c,g t 4 c I I i Saturation.(%) 91, c 9040 842%z w Dry Density(pcf) 9 IA qq. 1 lc.y z j ! • , • W Time for 50% Q i . , .LU Consolidation (min) U o 4,.. w Time for 95% co i I 1• o• Consolidation(min.) rn i : w Void Ratio after Lu z m Dry Density(pcf) Y I 1 ' • ; Water Content(%)U li ill 3t. 3a,1 z•o 1 z Void Ratio o. BoO 0.1-8- 0•1GZ 0.1c o I a•z e•j u' Saturation(%) 1 05.5 f o\•8 113•L( Normal Stress(psf) 1114,5 z.stq•L '5c4 4.S HORIZONTAL Maximum Shear(psf) i 134.0 o DEFORMATION (in.) 2°ee'° t. Time to Failure(min) Sample Source fil lip 83.o' Os= Classification Gs Ci _ r'L-)ksL Applied Geotechnology Inc. Direct Shear Test Report PLATE Geotechnical Engineering Geology&Hydrogeology 41.7r 11^14 L 1....—/ B 0,,!a t r W;TE k DRAWN APPROVED TE REVISED DATE 1444i 0 9t Jizs ST5 U.S.Standard Sieve Size(in.) I U.S.Standard Sieve Numbers 1 Hydrometer 3 11/2 3/4 3/ e 4 8 16 30 40 50 100 200 Relerence ASTM D 422 100 ,! I I. : I ; 1 II I il Hi ' I I I I I : : I1 90 i I i H I i • I ! 0 . 0 i 60 ; CO CC 50 z L Z 40 w U cc w CI" 30 20 i • ' 10 • t , I rf ! it 1 H ! i • '' 1 0 100 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0.001 GRAIN SIZE IN MILLIMETERS COARSE FINE COARSE MEDIUM FINE COBBLES GRAVEL SAND SILT OR CLAY Symbol Sample Source Classification O E- i pT- iC si L.-r (ML) i PLATE Applied Geotechnology Inc. Particle Size Analysis Geotechnical Engineering Geology&Hydrogeology Coe"4=6- /ha,wAt- WI%k. I JOB NUMBER DRAWN R DATE REVISED DATE I 40,1 'iP O3-OV-28 II U.S.Standard Sieve Size On.) --01-4---U.S.Standard Sieve Numbers—Ito-- Hydrometer 3 11/2 3/ 4 3/ a 4 8 16 30 40 50 100 200 Reference ASTM D422 HI IIII I II Of I !WI ! I II ! II; • i ! I . 90 i 111 ' 1 1,I. il, IJ I II Il 80 III 1 II i li 4 I ' l I I I NI . ', I 4ii • ; Ii i il i•I .1i1. 1 . ! I . : i d 11 If I ! ; i it, : : : : , l1 : I I f: I : : 1 li III il / 1 H l! 1 70 i 141. :: i114 q ;: i : il ! 11 . ! ' 11 ;. ; I I 4• • : : 4 : : : i H I . i I i II: : CO i , • II . q ' : • 60 i I • . I CO 1 CC III i .:' II I II • I.; ! I ! V • : . ' I ' • I 1 ' Li.' 50 I Z Ishii II i II .*4 ii, H . i I; •4i ; ; :1 cr. I— I ! : t,I ii i I II: i : z 40 i 1.1.1 I I i : ii il i ; : • : ' L i I 1 i . : CC LLI 11 li i !I i. 1 i ! I : H I I! i a' 30 : 1 i' " •- . . II '' ; I ': i .• 1 i I 1 , I i: i : ; : l 1 il di 1 i 1 I '• li: 1 1 1 1 I i• II!I 1 i : 1 ! I i I 1 IIIIII111ilI I I 1 ! 1 1 . 1 1 i i I I I Ili I ' i i : 1 •: 1. II •I I 1 I I I I 1 11 111i 10 .. I. Hi II I II il . I 1 It ! iiIIII 0 , iii ill 1, 11 , lid 1 I I h, 1,ii, ,, 1 , 1 11111,, 100 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0.001 GRAIN SIZE IN MILLIMETERS ICOARSE FINE COARSE MEDIUM FINE i COBBLES SILT OR CLAY GRAVEL SAND 1 Symbol Sample Source Classification i 0 810 S- 2.(v SILT Creii...J 1 Applied Geotechnology Inc. Particle Size Analysis PLATE Geotechnical Engineering Geology&Hydrogeology Ctiairt 14ILL/130mAILE: karcie— JOB NUMBER DRAWN A OVED REVISED DATE Pifff.dre leAR...liAiTE/eel j I Appendix B LOGS OF TEST BORINGS se6613/012/2 R :l..E_ NL-_. . SL-G1'..?t AU.-N,: N:iMBER: E—. S?E_— _ GF c 1 R2M HILL 1 SOIL BORING LOG I FR__tE_i: :E1.-uf: RDq ALIGN ENT LOCATION: SHALE ct- 1 cL;AT. ., E:: nY t DRILLING CCi' ^f:J^: E YENNER DRr•;_'.0 1 DRILLING E-rGD ..D EGUIPMENT1 .E 75 - MUD RCT rq i`TEi LEVEL a!: DATE. NOT REn S.ED START: 2_-_-68 FINICN: c-2T-SS L:ESE, • A.M.J,TE. i . 1 r SAMPLE 5T:. I SOIL DE°G"nl;TION IS COMMENTS L TEST SOIL NAME. COLOR, MOISTURE IM L DEPTH OF CASING,1 DEPTH TYPE I R , I BELOW INTERVF.LI A`1 I E CONTENT, RELATIVE DENSITY OR OB 0 DRILLING RATE. DRILLING SURFACE NUMBER C b'-b'-b`CONSISTENCY, SOIL STRUCTURE, I0 6 FLUID LOSS. TEST AN" I (FT) ! (FT) I I(FT)I (N) MINERALOGY, USCS GROUP SYMBOL IL I INSTRUMENTATION 1 1 , 1 0 SURFACE SAhu - POORLY bRAL;cD SAND, brown, — Test nole located on tre 1 sli;ht:y moist, fine to medium grained surface of a sand flow. -. S. , I 1 1 1 1 1 1 1 1 I l 1 I 1 I 1 I p 1 ; I (brave! at 4 feet. i I 5 ; S( I Si I .8 16-11-13 POORLY GRADED SAND, brown, moist to wet, I I I I I I I (24) medium tc fine grained, with occasional I I 1' to 1-1/2' minus grave! (SP). I I I 6.5 ; I I I I I j 1 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 t 1 1 1 1 Gravel at 9 feet. 1 1 1 1 1 1 1 1 1 1 1 1 1 I 10.0 I I 1 11.; 1 i 1 t 11 I I S2 I .A 119-16-1EI Sacs as above, except very fine grained I I I (36) ; with trace of fines in tip of spoon (SP). 1 11.5 1 r 1 1 1 1 1 1 1 1 1 1 l 1 1 1 1 1 1 1 1 1 1 1 1 1 1 15.4 1 , 1 11 1 1 1: ._. 3 i, 2 i t 1 SILTY SAND,hard 0 deposit th 1 S„ I1.: 1 lb-!5-.: S:L:Y brown, moist to wet, Lakeb_1 de,,o_i wi_:: I I I I (27) I with approximately 151 fines and occasional dropstones. --I f occasional grave. (SM) with thin I I I I 16.5 I I ; I interlayers of elastic SILT, brown, moist I I I I I (.NH to ML). 1 1 I 1 I 1 t 1 1 r 1 I 1 1 1 I I 20.0 ,1 I 20 - ' I I I S4 I1.3 12u-3i-=4I I I 7 . •T s,del 1 I I 1 1 1 (i?) 1 SILT, with approxima_ely 10% very fine 1 r san^., gray-brown with mottling, moist to 21.5 I wet, hard (M!). 1 1 , 1 i 1 1 1 , 1 1 1 1 l 1 1 1 I 1 t c 0 1 1 I 1 1 25. 1 1 1 t 25 --I 1 1 TS ; ; 1 t 25 1 P ,1. t I Pitche saxp!E' a: i 1 1 i Sate as above IML). feet. 1 1 / 1 1 1 1 1 1 1 1 27 5 I r I 1 r i 1 1 1 PROJECT Nr E. . S24E1-.:( BORING KJ ME z: B-1 SHEET: 2 OF: 5 CH2? HILL I SOIL BORING LOG PROJECT: CEO?RO" ROAC ALIGNMENT LOCATION: SEgM_c PIT E -nAT'.?: Est. •2,- DRILLING CONTRACTOR: DON KEhREG DRILLING DRILLIkE METHOD AND EQUIPMENT: C"_ 75 - MUD ROTARY WATER. LEVEL AND DATE: NOT RECORDED START: 2-22-89 FINISH: 2-23-GB LOGGER: B.M.WITE SAMPLE STD. SCIL DE3CRIP?ION-------I---------CO"MEM1'= I I PEN. Y 1-------- I DEPTH 1 TYPE : R : TEST SOIL NAME, COLOR, MOISTURE M LI DEPTH OF CASING, I BELOW :INTERVAL: AND E :---------CONTENT, RELATIVE DENSITY OR B 01 DRILLING RATE, DRILLING , SURFACE I NUMBER C 16'-6'-6'• CONSISTENCY, SOIL STRUCTURE, 0 61 FLUID LOSS. TEST AND I (FT) I (FT) I FT): (N) I MINERALOGY, USCS GROUP SYMBOL L I INSTRUMENTATION I 3u I 30.0 I SE 11.1 . 7-i1-29 SILT, gray, wet, hare [ML). t 31.5 ' • 35 - i I : 1 1 S7 11.0 1 13-31-32: Sane as above (ML). 1 I t , (63) : 1 I I-• I36.5 I I I I I I 40.0 : 40 --I SE :0.9 112-22-26: Sane as above with thin (One sand grain I 1 1 I (4E) I thick) fine sand partings (ML). 41.5 1 I 1 I I I I I I I I I I I I I I I I I II I 4`•.0 II1 1 PT9 11.E ! 1 I I I 1II 1 48.•^. I T , _? 3 yrrs^ t . S:! ,1.. 16 E-4:.. Saar as above, e.,_ec; tip has caa. Ssepler we:. 71) ; silty ncn-plastic silt or very fine silty 50 4R.5 I I I I I I ; t I 55.0 I I I I• I I 55 1 Sil :1.5 : 25-40-48: SILTY SAND/SANDY SILT, gray, wet. hard tc :Occasional discir; it i 1 ; Re) I very dense, ve w fine pocriy graded sand 1saaele 511. ML or S'! 1 56.5 ' 60 --1 I n•, .O F- T. Cn.JS... ytircc,. ._4::-.?t; 8;: .N. NMScn: S=_.. CH2w _ILL SOIL BORING L0G PROJECT: CEhT C; Rr F7 ALIGNMENT LO:ATI05: BEGuCr FIT I E1_EV At In Y: Est. •244 DRILLING „G,TRACTOR: DON Kc`NER DRILLING 1DRILLIYG CETHC: AN2 E• u,IPE T• CIC 75 - MUD ROTARY WATER LEVEL AID iA'E: N07 RE 3&:ED START: 2-22-93 FINISH: 7_23_22 LOGGER: S.".iITE 1 1• SAMPLE i STD. 1 Sfir. DESCRIPTION C 1 Y : nOMME`;T: PE' : DEPTH : TYPE : R : TEST : SOIL NAME. CGLDr"', MC:STLRE M Lt DEPTH OF CASING, • 1 BELOW :INTERVAL: AN : E : CONTENT, RELATIVE DENSITY OR B 0 DRILLING RATE, DFILIh : SURFACE 1 NUNSE3 : C : 6'-6'-6': 0 6 FLUID LOSS, TEST ANCCONSISTENCY, SOIL STRUCTURE, I FT) : (T) : FT): (N) : MINERALOGY, USCE GROUP SYMBOL IL INSTRUMENTATION 1 t 1 I I I I I I 4 60 : ov.0 ; S12 i1.: . 10-24- b: SiLI/ SAND to SANDY SILT, gray, wet, 52) : very dense to hard (SM to ML). I 1 1 61.5 i I _ I 1 t 1 1 1 I 1 I 1 • 1 I I 1 1I I 11 I1 I I 1 1 1 1 I 1 I t I 1 1 I 1 1 1 1 I 1 I I 1 I 1 1 1 I I 65.0 : 65 _,I I 1 I S1 :0.6 : 7-9-15 : Same as above (SM to ML) with occasional : :Switching ever to Dates & : I 1 , •1 . I a and I :Moore1II (c4; subrounde gravel layers up to 1 ,Mere saWpler at 55 feet. accroximately 2' thick of POORLY GRADED : : 66.5 : SAND, gray, wet, dense, medium grained : : I SF: I I 1 r 1 I I I I I 1 1 1 1 I I I I1 1 I 1 I I I ' I I I I 1 1 70. 1 I 1 1 1 I I 10 --i c I 1 914 1.0 1O-2 ' S .Sae as above (. tC ML) with poorily : I (32; : ara:ed sand and one 1/4' thick lens of : : ELASTIC SILT or LEAN CLAY, grey, moist, I : 71.5 hard (MH to CL). t I I I I I I I I I ' I I I 1 I I I t 1 1 t 1 I 1 I 1 1 t I 1' 75.0 1 I I 75 —f t IJ S 5 ", 9 Same as above (S'! to ML). 62) : 1 6.5 I I ; 4 I I ! I I 1 I I I I jI1IIIII I I I I I I I 1 I I I 1 I 1 I1 1 I GO --: I I P?:: . ,3'c as above (SMtG r: - Nal. have mCrc' :1 s rd'v zones onich washed cut of pitcher I :Upper .5— ap;:=2.a .? __! t tuze or lower_: re_over . Isla::gn. 1 I 1 1 t 1 I I 1 I 1 I I I 11 11 93.0 I I I I1 I 1 I 1 1 1 I 1 1 1 1 I I I I 1 1 I I 85 --: 1 I I 1 I 1 1 1 t tJ1111I 1 1 1 1 1 I 1 1 I 1 1 I 1 I I I I 1 I I I 1 t I • i 1. I j( 7} 7 1 y^ . 1 1 I 1 1 I 1 I 1 1 1 1 I 1 1 I SOIL BORING LOG F we r nrr_.,• .It: .q ,:•ru:•^ rr.T•n,.= SE:. - r.- ry 'cam. n t N../ r••r ,Rn9r^709, wn: `E.1':. r A y F: _F: LEDE 3.M.J: _Yes t::_ l,J aiL. ,c :lt_.`•b_. 5 a'-.0 G_ JaC... TYPE w • • wilt• IA . (•!11 1-. y i • DEFTH _ C S•, Y ROIL ln..t. _1 t._:,7:_RE ct :I 7E • 4yn TNT RELATIVE DENSITY Or 0: GRILLING RATE, GF1 ::5SL_F I.nly itinz• v E CONTENT, NUMBER r ' r , ;.: T S.:F •E S -5 -_ 1 CANS:ST :tyY, Ka STRUCTURE, 0 ti FLUID LOSS, TEST ;;; FT) 1 S"S ^"',e SYMBOL L INSTRJl1EN ATiC.`!FT) . (. •) F ): at; MINESALE Y, it L SCUP 1 I i ; 11.v ; bi ;_.z• ' 2i-.:t-,:r'; ?3,-J Y Ok;1LE 5A%; w::h tun layers of I Color cnange tc 1: ;::_ i Epp• • ?vast:c silt, light brown/gray, lest}} brn. very dense (S='(.•av have enough silt tc 1.5 classify as (S!-SF)). 95 Si= ;1.` • 34- SILTY SAE with layers of SILT, gray, a : wet, very dense, fine to aediva grained sand, orange octtling in sell area o: 9c Icwe part Jf saapler (SM to ?L; 1.. -_'- :erOedd93 FCC'_ SPACE: SAN:, dray: es' •tense, se:.'! •jrai:.cl sal•:. ,*. ; wi.. , c.L . gray, we:. .n.2r., no aottling (If.). : Harder drilling a`_ 1: '- feet. 1•1 IC! r: :r,: ' T -_ c -cJC_' :c:- SAN:, gray, aci°_, ver, : :Drilling auc in ii2:.E sns?, fine to ]eoi d•.grained sand (S';• : :bac Si:). s f I.Cam_ •L4-Zt• . S , -r:•, we:, r•ar (,rL;. Yak ccr:a:: rso'S$ tf• sY ap rowi ate 5,-:.. i. very fine er:.. FROJE_T 11L'3ER: SL7:_4.F) BORING NCNBES.: P-I SHEET: t CP: t CH2M HILL SOIL BORING LOG FRvi_DTc CEN'RON ROAD ALIGNMENT LOC±TICN: SHALE FIT t ,OR: DON K_NNEELEVATION: Es:. '244 DRILLING CONTRA h DRILLING DRILLING ME'HDD.AND EQUIPMENT: CMG 75 - MUD ROTARY WATER LEVEL AND DATE: NOT RECORDED START. 2-22-B3 FINISH: 2-23-SS LOGGER: B.M.WITEi SAMPLE STD. SOIL DESCRIPTION S COMMENTS I I FEN. y ~~---- - DEPTH : TYPE R I TEST SOIL NAME, COLOR. MOISTURE M L DEPTH OF CASING,BELOW :INTERVAL' AND E : CONTENT, RELATIVE DENSITY OR B 0 DRILLING RATE, DRILLINGSURFACENUMBERC16'-6'-6', _ CONSISTENCY, SOIL STRUCTURE, -0 6 FLUID LOSS, TEST AND FT)FT) FT)' (N) MINERALOGY, USCS GROUP SYMBOL L INSTRUMENTATION I 120 : i I 1 1 I 125.0 : 125 - r S22 :0.8 : 34-60/6': SILTY SAND to SILT, gray, Net, dense to hard, very fine grained sand (SM to ML). I 126.0 : 1 130 t t 135.0 I 135 ~, I PT2 :1.0 : SILT, gray, wet, hard (ML) 136.0 I I t by -- 1 I I I 145 --: I I Instaiied ohservat c well. flushed ht:a wit-. -- Clear water. 143.5 ! i i 2 iont surer. fro.' Ili --: t= 15` feet. i 24 ,3,4 Gr• CC1: SPADED A,• n; atdense, rr a1 packed t: _ .. -- 14$ tt _ a-aped fee t Eti: SDI: EE:":Ni A 1+:.F F[... ltoa+ s rfade. PROJECT NUMBER: S24614.80 BORING NUMBER: B-2 SHEET: 1 OF: 1 : CH2M HILL SOIL BORING LOG PROJECT: CE':TRC:; ROAD AL ISNME:';T LOCATION: SEGALE PIT LEVATION: Est, `28G DRILLING CONTRACTOR: DON KENNER DDRILLING 4RILLTNE MEMOD.AND EGOIP"ENT: CME 75 - MUD ROTARY WATER LEVEL AND DATE: NOT RECORDED START: 2-24-89 FINISH: 2-24-88 LOGGER: B.M.NITEK SAMPLE STD. ;SOIL DESCRIPTION S : COMMENTS PEN. ; Y 1---------------- DEPTH : TYPE ; R ; TES'-_1 SOIL NAME, COLOR, MOISTURE M L: DEPTH OF CASING, BELON :INTERVAL: AND : E CONTENT, RELATIVE DENSITY OR B 0; DRILLINS RATE, DRILLINS SURFACE NUMBER 1 C 6'-6'-6'CONSISTENCY, SOIL STRUCTURE 0 G: FLUID LOSS, TEST AND FT)FT) FT) (N) MINERALOGY, USCS GROUP SYMBOL L 1 INSTRUMENTATION i—; Hard & gravelly - losing circulation - thickened -- laud, still losing circulation. I I , I 5 --i Si : .2 ; 45-48-32: POORLY GRADED GRAVEL, gray to brown/gray, wet, 80) . very dense, 1/c to 3/4 angular rock , likely broker by drilling) (GP). 6.5 10.0 10' -- S2 ; .4 ; 17-34 ; Sate as above, except gravel up to S2 stopped 6' short. 1-1/2' Sample contains some bentonite Spoon going down at 11.0 ;mud (6P). angle betweenrocks, would bend if continued. -- Had to abandon hole, too crocked, will try at new - location. Drill red bent. I 15 -- I I 20 --' I 1 1 I I I I I I 25 -- I I I . I r.CJE_:T h_MEFR: cx_e.110 BORING hUMEER: 6-2_ SHEET: : CF: CH2M HILL SOIL BORING LOG PRCJE T: CEXTRON ROAD ALIGNMENT LOCATION: SESALE PIT CLEIiaTI3N: Est. r2 F.n f I t ,e Tr•1, iDRILLINGCONTRACTOR: DON KENNER DRILLINE DRILLISE METHOD ANC EQUIPMENT: CNE 75 - MUD ROTARY WATER LEVEL AND DATE: NOT RECORDE: START:"2-24-88 FINISH: 2-24-S8 LOGGER: B.M.NITEK. SAMPLE STD. :SOIL DESCRIPTION S ; COMMENT: PEN. : Y DEPTH : 1 TYPE : R : TEST : SOIL NAME COLOR, MOISTURE M L DEPTH OF CASING, BELOW ;INTERVAL: AND E : CONTENT, RELATIVE DENSITY OR - B 0 DRILLING RATE DRILLIN: : SURFACE ; NUMBER C : 6°-6'-6'CONSISTENCY, SOIL STRUCTURE, C 6 FLUID LOSS ThhT AND FT) : (FT) : FT); (N) MINERALOGY, USCS GROUP SYMBOL L INSTRUMENTATION u See Soil boring log for I B-2 for descriptions of --: samples above 15 feat. 4th location for tea: --: boring E-2. Drove casino to 10 1 1 :feet. Hit clay at approximately 9 feet. --' Will try Dames i Moore : 5 -- sampler to see if it wi1 --: I : fit through casing. Drilled to 15 feet then --: Sd.4.ple:. I I 1 1 1 ,I I 1 I I I 1 1 I I I I I I I f I I 1 I 1 I I 1 I I1II I1 I I 1 10 — I . I I I I . 1 I I I I 1 II 1 I I 1 I I I I I I I I I I 1 I I I 1 I I 1 I I I 1 1 I i5.0 15 — Si :1.5 : 1-4-3 : Too 4'; SILTY SAND to SANDY SILT, gray, Sample S1 taken with 16.5 : 7) : wet, medium firm (SM to ML).Dames & Moore saop!er. -- Bottom 14': LEAN CLAY, gray, wet, medium : firm (CL). 17.0 ST: :2.? ; Material seers to firm -- 14.0 at 5ottoe of Shelby tL s I push. 53 11.5 : 4-4-7 : LEAN to FAT CLAY, brown, wet, stiff (CL 2C -- 1 1 1 11) ; tc CH). S3 taken with SFT 2" to 3' layer in center of sam;le: sampler. 20.5 : 1 SANDY CLAY, brown, wet, approximately 20% : I I tedium to fine grained sa::. (C: . I I 1 I Hit gravels at _: fee:. 25.0 1 25 -1 I SL :0.7 : 42-47- : POORLY GRADED GRAVELLY SAND, brown, 60/5" ' moist, very dense, may be weathered till, ; I f approxinately 20% to 57 :" eir. s gra•,ci, ; 6.4 rook in saeo.e broken, likely larger rock i eon: (C:` I I 1 ;re_ 1 1 I 1 I .1 I l -1 I I 1 1 1 PRCJ E C' NOME E.. 32-.1..7 BORING NUMBER: B_2C C'7LE.. _ CP: C.•r r SOIL BORING LOG PROJECT: CENTRO; ROAi ALIGNMENT LOCATION: SESP_E PIT ELEVATION: st. 2E2 DR. LING CCNIR,w R: DON KENNERDRILLING DRILLINGLING METH; AND E_ IPME'T CME 75 - MU:' ROTARY RATER LEVEL AND DATE: NOT RECORDED START: 2-74-SS FINISH: 2-24-69 LOGGER: B. ..«1 EK SAMPLE ra. ,SC,L DESCRIPTION S I C0411P I S PEN. ' Y I DEPTH : TYPE' : R ; TEST : SOIL NAME. COLOR, MOISTURE M L: DEPTH OF CASING, BELOW :INTERVAL: AND ; E : CONTENT, RELATIVE DENSITY OR IS 0: DRILLING RATE, DRILLING ; SURFACE : NUMBER : C : 6'-6 -6": CONSISTENCY, SOIL STRUCTURE. 0 6: FLUID LOSS, TEST AND FT) : (FT) : FT): (N) : MINERALOGY, USCS GROUP SYMBOL ' ft : INSTRUMENTATION 30 . : 3u.0 ; E5 ; .t ; So-oui 4.: PUURL7 GRADE. SAND, gray/brown, sligntiy :—: moist to moist, dense, fine grained sand : : 30.9 1 SF). I I I I I I I I I I I I I 1 I n I I I I I I I I I , I II35.0 I I I I I 35 —! I 0.4 : 6O!" SANDY SILT to SILTY SAND, gray/brawn, ; 35., Sb moist, hard to very dense, thinly layered ML to SM). Gravels at 37 feet. I I I 1 I I 1 Sand at 39 feet. 1 1 1-- 40.5 ; I I I I I I 1 I I • I 1 I I I I I Gravels at 43 feet. I I I 45.^ tJ __l I S: IC'._ 60!i" ' SILTY GRAVEL, brown, moist to wet, very : 45.3 i dense, approxiaately 40% SI:T. subrounded : grave:, larger gravel is broken, angular : 1 I I I 50.0 : f . . I I O.,, • r CO( S op •1 • it is ,I 50.: &? NR b.-_ . N RECOVERY. a_rle looks _xe bounci,g try Danes t Macre 1 samaler. Very slow G.illirc, 1 1 over an ra:r to dril f 1 ; foot interval from 5f t_ _ 1 55 feet. I I I 55 - IS: • 0.2 6:. I ROCKS. to diameter with 1 I 55.4 recovery of crushed rock in a matrix of ' silt, Say to SITI . 1 I I I I I I I , II I a I I PROJECT NJ SE : SC4614.P0 1 BC RING NUMBER: R 2E SHEET: . OF: I I CHCM HILL SOIL BORING LOS FROjECT: CE"NTROa ROAD ALIGNMENT LOCATION: SESALE PIT ELS')ATION: Est. '2E2 DRILLING CONTRACTOR: DEN KENNER DRILLING DF::LING METHOD AND EDUIRME`:T: CME 75 - MO ROTARY gATER LEVEL AND DATE: NOT RECDFDEO START: 2-24-38 FINISH: 2-24-ES LOGGER: B.M.IITE: SAMPLE I STD. 'SOIL DESCRIPTION IS COMMENTS FEN. ___------______------_________--------------;Y ----------_ DEPTH : TYPE : R TEST SOIL NAME. COLOR, MOISTURE M L DEPTH OF CASING, BELOg :INTERVAL; AND : E CONTENT, RELATIVE DENSITY OR B 0 DRILLING RATE. DRILLING SURFACE I NUMBER : C 6'-6'-6'CONSISTENCY, SOIL STRUCTURE, 0 6 FLUID LOSS, TEST AND FT) : (F?) : l(FT)I (N) MINERALOGY, USCS GROUP SYMBOL L INSTRUMENTATION 1 1 1 1 / I 1 I 1 1 1 1_ 1 6 bv.0 S11 :O.: : 53-bn5 BROKEN 6RAvEL and IDDE= SAND, wet, dense, drilling mud in sample (GP, SP). 60.9 I 1 I I I1 I 1 I I I I I 1 I I I I I I I I 1 1 I I I 1 65 — 1 , 1 7 1 I 1 I I I I I I I I I I I I 1 I I I I I I I I I I I I I 1 I 1 I I I I 1 1 I 1 I I I I I 1 1 I I 1 I I I 1 I I 1 I I I I I 1 I I I I I I I I I I 1 I I I I 1 I I 70.0 : Drilling changed at 69.5 : 70 -- feet. S12 0.9 : 47-60/5°: SILT, brown in upper 3' to 4', gray below, moist to wet, very hard (AL). Layered unit, lakehed --: 70.9 deposit. I I 1 I I 1 1 I I I I 1 I I I I 1 I I 1 I I I I 1 I I I I I I 75.0 I i• 1 75 S13 10.9 : 33-60/5'; SILT with GRAVEL, gray, wet, hard.Appears to be back in tel lOX to 20X.aravel 1' to 2'till. Small fractured -- I 1 approximately 1 1 1 1 3' 4' n 3I75.9 I I large gravel, with to thick tones of . (:)tone in sample SI , I wall rounded gravel (ML). brown to gray in color, --: slightly exist, almost 1 1 looks brecciated. 1 t 1 1 I I I I I I 1 I 30 Alt 6! ` " • SILTY SAND, gray, wet, very dense, 20X to EC.5 I 30X fines, fine grained sand, with occasional dropstcnes - till (SM). 1 I I 1 I I I 1 I I l 1 I I I I 1 I I 1 I I 1 1 I 1 I I I I I 1 1 I i I I 1 I I 1 I I I I I 1 1 1 1 I 1 1 •aC —I I : I I I t -. I I I I I I 1 I I I I 1 1 l I 1 1 1 I I I I I t I i I I I I i I It I i I I 1 t i t 1 I 1 1 1 1 I I I I I 1 I I 1 I I 1 I I 1 1 l 1 I i I i PROJECT NUMBER: S24614.B0 BORING NUMBER: B-2P SHEET: 4 OF: . CH2M HILL I SOIL BORING LOG PRC ECT: CENTRON ROAD ALIGNMENT LOCATION: SEGALE FIT ELEVATION: Est. 4282 DRILLING CONTRACTOR: DON KENNER DRILLING DRILLING METHOD AID EGUIPMENT: CME 75 - MUD ROTARY 1 WATER LEVEL AND DATE: NOT RECORDED START: 2-24-SE FINISH: 2-29-88 LOGGER: B.M.W TE" SAMPLE STD. 1 SOIL DESCRIPTION S : COMMENTS DEPTH : TYPE 1 R I TEST : SOIL NAME, COLOR, MOISTURE IN LI DEPTH OF CASING, BELOW :INTERVAL: AND I E 1- --1 CONTENT, RELATIVE DENSITY OR 1B 01 DRILLING RATE, DRILLINQ ' SURFACE 1 NUMBER : C I S'-6'-6': CONSISTENCY, SOIL STRUCTURE 0 6: FLUID LOSS, TEST AND I FT) I (FT) : . :(FT): (N) 1 MINERALOGY, USCS GROUP SYMBOL L : INSTRUMENTATION I 1 1 1 1 9G { 9u10 i PT-5 ;v.5 SANDY SILT, gray, moist to wet, hard 16riliec 1 foot wnen i ML). something plugged,pua:, --: 1 91.0 : had tc bring sampie up early. I 93.0 1 1 I t S16 1.3 : 25-45- 1 SILT gray, moist to wet very hard with Changed frog till to a 1 60/5.5" : thin (one sand grain thick) partings of massive silt deposit. --. I fine grained sand spaced erratically 95 --1 94.5 : I throughout sample (ML). I I I , I I I I . I I I I , I , I I I I I I I I I I I I I 1 I I I I I I I 1 I I I I I I I I I 100.0 1 I I I 100 _ 1 1 S17 'i 5 1 17 ' '° Same as above, except with silty sand I : I layers up tc 1-1/2" thick (ML). 1101.5 : I I I I I1 I I I 1 I I II I I I I 1 I 1 I II I I I I 1 110.t I 1i --I I EIS :0,6 132-6c'/2':• SAND`" SILT to SILT, gray, wet, very hard Still hitting rooks as . 11i;.i ML). drill down. I I 115 -- 1 1 I 1 I t 1 I I I I I I I I I I I I 1,\ I . I I I I 1 1I 1 PROJECT N..:!SE1: 7126:!... i Dri+T RDP11^.. -LC PEE : ; u:-; CH2`: HILL SOIL BORING LO6 PRO,;ECT: CENTRO': ROAD ALIGNMENT LOCATION: SESALE FI! I ELEVATION: Est. `2Sn 1 CONTRACTOR:CT R C' II t 1 GDn':_LIAS CuNTnA;,Cn D,,.• XEtiNE; DRILLING r , n .AN n. • ,r. CM - 1 ROTARY I DRILLING METHOD D EOUIPME'1. „ME 75MUD ROAR WATER LEVEL AND DATE: NOT RECORDED START: 2-24-66 FINISa: 2-29-3S LOGGER: B.M.WITE S4"F'`E-----------STu;--i------------SOIL DESCRIPTION M S COMMENTS PEN--; Y :------"' 1 DEPTH : TYPE : R : TEST : SOIL NAME, COLOR MOISTURE M L: DEPTH OF CASING, BELOW :INTERVAL: AND : E : CONTENT. RELATIVE DENSITY OR B 0: DRILLING RATE, DRIL IN SURFACE : NUMBER C 6'-6'-6': CONSISTENCY, SOIL STRUCTURE, 0 6 FLUID LOSS, TEST AN: FT) : (FT) : FT) (N) : MINERALOGY, USCS GROUP SYMBOL L INSTRUMENTATION 1 1 1 120 : r i2U.0 : S:`i :1.5 : 23-4`- : SILT, gray, wet, very hard, wan sand : :I 60/6' 1 parting:, massive, with occasional rounded gravel (ML). 1 n C 1 I 1 121..1 1 , 1 1 1 1 1 I 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 I 1 I 1 I 1 1 1 I I I 1 I 1 1 1 I I I 1 I t 1 1 1 I 1 1 1 1 I I 1 1 1 1 1 I = 1 I 1 1 5 -- 1 1 1 I 1 1 I : 1 1 I 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 / I 1 1 1 1 I I I 1 I I I I 1 I I I 1 1 I 1 I 1 I r 1 1 1 I I 1 I I I ' I 1 I 1 I I 1 I I 1 1 1 1 1 1 1 130.0 1 1 I 1 130 S20 :1.5 : 19-33- : Sase as above (ML). I I 1 t 1 1 I I 131.5 : 1 1 1 I I 1 I 1 I I 1 I I 1 j 1 I 1--, 1 1 1 1 1 1 I 1 1 I 1 1 1 I1135 -- 1 1 1 I 1 1 1 r 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 , 1 1 1 t 1 1 ' 1 1 I114C11 140 11 I 1 1 1t0.o : I I 1 t I 1 I t I I 1 1 I 1 I 1 t 1 1 1 1 1 I 1 1 I I 1 ! 1 1 a 1 a 1 1 1 1 I t i I I J --1 1 1 I 1 1 1 1 I I I 1 1 11 1 1I I I I 1 I II 1 1 1 1 a I 1 1 1 1 1 1 1 I1 a a 1 I 1 . a 1 1 jC1 1 I r b'1 1 1 , 1 1 1 1 FLJECT NUrEER: S =ti4.20 BORING NLIMEER: 8-25 SHEET: t CF: - CN !! FILL SOIL BORING LOG I PROJECT: CENTRGN ROAD ALIGNMENT LOCATION: SE9ALE FIT ELEVATION: Est. '292 DRILLI,S CONTRACTOR: DON KENNER DRILLING DRILLING METN3D AND EQUIPMENT: CME 75 -.MUD ROTARY WATER LEVEL AND DATE: NOT RECRDED START: 2-14-88 FINISH: 2-29-89 LOGGER: S.M,+'I'E f---- 1-------Af'fLE --------_ST?.- -----------SO1L DESCRIPTION S COMMENTS 1 1 DEPTH ' TYPE : R : TEST : SOIL ;TAME. COLOR, MOISTURE M L' DEPTH OF CASING. 1 BELOW :INTERVAL: AND : E ' CONTENT RELATIVE DENSITY OR B 0: DRILLING RATE, DRILLING SURFACE NUMBER : C : 6'-6"-6': CONSISTENCY, SOIL STRUCTURE, 0 6' FLUID LOSS, TEST ANC FT)FT) : FT): (N) : MINERALOGY, USCS GROUP SYMBOL L ' INSTRUMENTATION 1 1 I I I I 1 1 1 1 1 150 . 150.0 ; Su .O./ • 19-25-55 SILT, gray, wet, veryhard, with sane :---1 1 partings, Aassive, with occasional I I 1 gravel (ML). 111 151.5 1 11 1 1 1 Drilling started tc . harden uF at 153 feet. I I 1 I I I I I I I III 155 -- I I I I I 1 1 I I I 1 I I I 1 I I I I I 1 I I I I 1 I I I I I 1 I I I I 1 1 I 7 1 I I I I I I I I I 1 I I I 1 I I I 1 1 I 1 1 I I 1 I I 1 I II I I I I 1 I 1 I I 1 I I 1 1 1 1 I I I 1 1 1 I 1 I I I I I • I 1 I t I 1 1 IL , v\ j t 1 I 1 I I 1 I I 1 I I S2: :0.8 , 44-50/6': SILT, as above with faint trace of I ' bedding in sandier layers (ML). Silty : ' 161,0 : sane in tip, gray, wet, very dense (SM)I : : I 1 1 1 I 1 1 1 I 1 I 1 1 I 1 I 1 1 1 I 1 I 1 1 I I I : 1 I I 1 1 I I I I I I 165 -- 1 1• 1 1 I 1 1 f I I I 1 wl 1 I I I 1 1 I 1 I 1 1 1 1 1 I 1 1 1 I I 1 I t I I 1 I I t 1 1 1 I 1 t 1 I 1 1 1 1 I I I I 1 1 1170.0 , 1 1 170 --I t SILTY SAND, gray, wet, very dense, 202 1 S_d :V.. 6c/5.5' to vO fines, very fine grained sand 1 170 SMi After wee)send difficult tc cet rcds down. i Hole full of water, to recrill portions o` I hole. 1 1 : f I I I I I I I I I I 1 I 175.E 175 --: Sale as above (SM). S25 G. 47-60/3' 1 I 1 I 175,8 : I I I I I I 1 I 1 I I I I I 1 1 I , I I I 1 1 1 I 1 I 18r1 '.1 1 f • 1 CFI-1 -it._ SOIL BORING LOG FINE"^`-r- C.- '+ CAn A• - t!rSNT 3E5A.. PFL. Rt. rlvrc n :C :_a M.M, _ I. JCJ.._. 1 ^_.,TIr. 171 w: i 1: •+TS-r.•. T[ M a (.E!4w.t L li/i Y:I»::tC f r 1_2•tiC .r4 ea. L!'.a. t . Cr.:•.i•L r - Mg .. 4: T_ _ A.rs Yw-rQ '-? It.... - • ES: ^-2C_7' 1 1T^ : f: a..4.A41E' :DE_ "21 Iu+ E:NDU" Itnf: 1--QO iN: 1 f.Y1:7 P_', 7 DEPTT•J - SOIL N/ C I fl^ n URE 4 . 1 3 q_..l T C-1•_ t.} i L ^ :r: SU a. NAME, ut,A MOISTURE Erld 3F r:fr:•IC. BEN 1 NT_ •A• f AMA 1--- CONTENT.y E•T TI DENSITYITV I I T T- •. '•,- . 1 E-cw•• IltTlcflin., n1I1, E I ------ , IvT r. RELATIVE uEl/s.t: Ia 46 oR:__.KE k, phi__- : C Illl MSF 1 tl- V- 71 C t1 T I j D •1SS -EST A.t•!SSuRrm_ : I..:I,:Jc.. . C b 6 1 ,OtTSiS1EhC , SOIL STRUCTURE. IC S FLUID LOSS. r (FT) i (FT; : FT)! (N; MINERALCSV, UECS GROUP SYMBOL INSTRUMENTATIC I 1 1 I I I I I t I 16i . 1 _.,•,if - o.:,, iv.,:: • 46-44.c . 5ILT: gray, NEC very nard,w to 1 i 1 f:c:as_oa: very fine graiaea sand (ML). i I I I I 1 1I t f f I t I 1 1 :Installed O'tsar a::dd: i I I I I iwe-1. i i i F:us''.ed hcie o drrill_ I laud. i 195.0 : r installed 2 foot E:res7 • 195 --I fro: /83 to :8° festt. --! • I SILT, gray, Me:, hard (Mc.).Grave: pl ef.ec no:` a-_ i sealed win foot 1 ..o t Erlc ___ BORit/ a, ? .6 FE:_. SEPI G 11tE cyst, 1 1 I f I f I f I S I i 1 I 1” I I I f r I 1 1 I I I 1 I• I r t I t 1 1 f 1 1 1 1 I 11 f 1 . 1 I I 1 1 1 1 1 1 111 1 19! i 1• t 1 t1 1 1 t 1 I I I I 1 1 1 j 1 . 1 1 i 1 1 I 4. I t . 1 c Golder Associates CONSULTING GEOTECHNICAL AND MINING ENGINEERS REPORT TO CENTRON PRELIMINARY HYDROGEOLOGIC-GEOTECHNICAL STUDY MCMAHON PROPERTY RENTON, WASHINGTON f Cistribution: I copy - Centron Bellevue, Washington 1 copy - Dodds Engineers, Inc. Bellevue, Washington 4 copies - Golder Associates, Inc. Redmond (Seattle) , Washington January 1988 873-1161 GOLDER AS;OCIATES.INC.•4104-1a8TH AVENUE N.E.REDMOND(SEATTLE).WASHINGTON 98052.U.S.A.•TELEPHONE/206)883-0777•TELEX 5106002944 OFFICES IN CANADA•UNITED STATES•UNITED KINGDOM •AUSTRAUA 73 Golder Associates CONSULTING GEOTECHNICAL AND MINING ENGINEERS January 11, 1988 Our ref: 873-1161 Centron 3)25 112th Ave. N.E. , Suite 100 B?llevue, Washington 98009 A T ENTION: Colin Quinn RE: PRELIMINARY HYDROGEOLOGIC-GEOTECHNICAL STUDY MCMAHON PROPERTY RENTON, WASHINGTON D'lar Colin: Iii accordance with your request we present herein the preliminary results of our hydrogeologic-geotechnical engineering study of the MI:Mahon Property in Renton, Washington. The site is located as shown on tie attached Vicinity Map, Figure 1. We have proceeded based on your November 1987 written authorization. Tlie purpose of our study was to complete a preliminary assessment of: the feasibility of the proposed groundwater retention/recharge system the overall stability of the pit walls, bluff face and foundation conditions for the proposed apartment buildings 1. PROPOSED DEVELOPMENT It is our understanding the proposed development will generally consist of two or three story, wood frame, residential apartment buildings with accessory paved driveways and parking areas. Although building locations have not been selected, we have assumed the buildings will be located on the hillsides surrounding the pit. A series of ponds have been proposed as a storm water retention and groundwater recharge system in the base of the pit. In addition to the structures and the ponds, an access road is to be constructed from the site, down the bluff to the Maple Valley Highway. GOLDER ASS JCIATES.INC.•4104-I48TH AVENUE N.E..REDMOND(SEATTLE7,WASHINGTON 98052.U.S A.•TELEPHONE(2061 881-0777•TELEX 51060029AA OFFICES IN CANADA •UNITED STATES•UNITED KINGDOM•AUSTPALIA Jaruary 11 , 1988 2 873-1161 2 . SITE DESCRIPTION The site is an L-shaped 120-acre parcel located within the E 1/2, NW 1/4 and portions of the N 1/2, SW 1/4 of Section 16, T 23 N, R 5 E in Fenton, Washington. The site is a former gravel pit operated by Segale Construction. It appears that large scale gravel mining has not occurred recently; however, stockpiled sand was being hauled off site on January 20, 1987. The property boundaries are formed by the following features: 1) On the west, Mt. Olive Cemetery. 2) On the south, the Maple Valley Highway and a series single family homes. 3) On the east, a King County transfer station and the King County Public Works shop. 4) On the north, a vacant lot which is currently being used as a dump for demolition debris. In general , the site consists of a central , north-south trending relatively level pit floor, where the gravel pit operation appears to have been concentrated. The base of the pit is flanked by steep slopes generally rising 40 to 70 feet above the gravel pit floor. The western portion of the site is a broad, relatively flat, upland containing several small borrow areas. The eastern portion of the site is similar to the western side, however, it is lower in elevation, appears to have teen worked less and contains a series of sand and gravel dump piles. The southern portion of the property is dominated by a steeply sloping bluff face which slopes (approximately 25 degrees to near vertical ) towards the Cedar River, and the Maple Valley Highway. The bluff has an elevation drop of about 170 feet from the floor of the gravel pit to the Valley bottom. The steep bluff on the south portion of the property is generally heavily vegetated and supports a variety of horse tail grasses and ferns. These plants typically indicate water is at or near the surface during much of the year. However, no seepage was observed along the slope during July through December of 1987. The bluff also exhibits several small scars as a result of recent sloughing. The slope stability map of King County, by Miller (1973) , naps the slopes along Maple Valley as being unstable due to natural processes such as undercutting by the Cedar River and the sand and gravel mining activities of man. Further discussion of the stability of the bluff is presented in later sections of this report. A___ _,_.__ January 11 , 1988 3 873-1161 The floor of the gravel pit is generally void of vegetation and contains numerous shallow ponds (less than five feet of depth) , shallow swampy areas and several ditches draining to the north. Access to the property can be made from the northwest and northeast by using existing dirt reads off of N.E. 3rd Street or from the south by an existing road off or the Maple Valley Highway. 3. FIELD EXPLORATION Our subsurface exploration program consisted of field reconnaissance of the site, a mapping of the surficial soils and groundwater seeps, and the completion of six hollow-stem auger borings. Our exploration was completed during the period of October 28 through November 18, 1987. 3. 1 Borings Tre approximate locations of the borings completed for this study are presented on the Vicinity Map and Site Plan, Figure 1. The borings were lccated in the field by taping from existing site features. Borehole elevations were interpolated from the contours shown on the boundary and tcpographic map of the McMahon Properties provided by Dodds Engineers, Irc. , dated February 5, 1987. The locations and elevations should only be considered approximate. The borings consisted of advancing a four-inch inside diameter hollow- stem auger with a truck-mounted, Mobile 8-61 drill rig. During the drilling process, disturbed but representative samples were obtained at tko and one half foot depth intervals for the first 19 feet, then at five foot intervals to a maximum depth of 99.0 feet. The borings were drilled under the full -time observation of a staff geotechnical engineer from our firm. Records of all the boreholes were kept in the field as the drilling took place. The borehole records were based on the drilling action and inspection of samples secured. The boring logs were later refined with the aid of laboratory test results. The various soil types encountered as well as the depths where the soil types or soil characteristics changed are indicated on the boring log. It should be noted that these changes may have been gradual , and if the changes occurred between sample intervals, the depth of the change was interpreted. Therefore, stratification lines shown on the records represent the approximate boundaries between soil types; actual transitions may be either more gradual or more severe. The soil and groundwater conditions are those recorded for the dates indicated, and may not necessarily represent those of other times or locations. Edited borehole logs are presented in the Appendix to this report. Golder Associates January 11 , 1988 4 873-1161 3 .2 Soil Sampling Cisturbed but representative samples were obtained at two and one half foot depth intervals for the first 19 feet, then at five foot depth intervals for the remainder of the boring. Samples were obtained by using the Standard Penetration Test (SPT) procedures in accordance with ASTM Specification D 1586 84. This test and sampling procedure consists of driving a standard two-inch outside diameter split-barrel sampler a distance of 18 inches into the soil with a 140-pound hammer dropping 30 inches in free fall . The number of blows required to drive each six inches of penetration is recorded, and the number of blows required to drive the sampler the final twelve inches is considered the standard penetration resistance (N) or blow count. The resistance, or N-value, provides a measure of the relative density of granular soils and the relative consistency of cohesive soils; these values are presented on tie borehole records. Soil samples obtained from the split-barrel sampler were classified in the field and representative portions placed in airtight containers and returned to our laboratory for further examination and testing. For environmental screening purposes a representative sample was collected in the upper nine feet of the native materials encountered in Borings 1, 2, 3 and 4. All environmental screening samples were retained in specially prepared glass jars with Teflon lids supplied by the analytical testing laboratory. All the soil samples were kept chilled in the field or refrigerated in our laboratory. Samples were transferred within the recommended holding times to an analytical laboratory, (Analytical Technologies Inc.) in -accordance with the recommended procedures of: U.S. EPA. 1982d (Updated 1984) . Test Methods for Evaluating Solid Waste- Physical/Chemical Methods SW-846. Office of Solid Waste and Emergency Response. Washington, D.C. Sample documentation included Sample Integrity Data Sheets and Chain of Custody Forms and are presented in the Appendix to this report. 3.3 Monitoring Wells and Pump Test Groundwater monitoring wells were installed in Borings 1, 2, 3, 4, and 6, with a maximum depth of 95.0 feet. The well casing used in the monitoring wells is a two-inch diameter, schedule 40, PVC standpipe with flush threaded couplings. The well screen slot size is 20 thousandths of an inch. All of the standpipe was cleaned and packaged at the manufacturing plant. Silica sand was used to backfill around the well s:reen and a bentonite slurry was used as a seal . A locking steel mDnument was installed over each groundwater monitoring well . Diagrams of the well constructions are presented on the borehole records in the A:pendix to this report. Golder Associates January 11 , 1988 5 873-1161 The groundwater monitoring wells were developed on November 11 and 12, 1987, using a PVC bailer (one valve) for Wells 1 and 3, and a gasoline engine centrifugal pump for Wells 2, 4 and 6. The monitoring wells were pumped and bailed until the water was clear. A constant flow pump test was conducted on November 18, 1987, using a gasoline powered one-inch diameter two-stroke centrifugal pump. The drawdown of the water table was monitored using a Thor Data Logger in the pumped Well BH-6 and a Solinst water level indicator in the observation Well BH-4. An extraction slug test was conducted in Well BH-2 using the Thor Data Logger to monitor the head recovery after twenty seconds of pumping. The pump test results are presented graphically in the Appendix of this report and discussed in Section 6 of this report. 4. LABORATORY TESTING 4.1 Geotechnical Laboratory Testing The laboratory testing completed as part of this study consisted of determining the grain size distribution of the soils, from five to 29 feet in depth, in Borings 2 and 4. Grain size distributions were determined in accordance with ASTM 0 422 63 and the results are presented in the Appendix to this report. 4. ! Environmental Contaminant Screening A limited water and soil contamination analysis was conducted to determine the baseline water quality and as a screening for possible contamination of surficial soils. The results of the laboratory chemical analysis will be presented in a separate report. 5. SUBSURFACE CONDITIONS 5. 1 Soils In general , the soils encountered during our field reconnaissance and in our borings consisted of the following: Recessional Outwash Compact to dense, brown, fine to medium SAND, trace silt Compact, brown, medium to coarse SAND and gravel Golder Associates January 11, 1988 6 873-1161 Lodgment Till Very dense, grey, silty, fine SAND, trace clay Advance Outwash Very dense, brown, fine to medium SAND, trace silt Very dense, grey-brown, fine GRAVEL, little to some medium to coarse sand Very dense, grey, silty, fine SAND, trace clay, trace gravel Glaciolacustrine Deposits Very dense, grey Clayey SILT, little fine sand PreVashon Undifferentiated Glacial Deposits Very dense and hard deposits of older till , lacustrine deposits of silt and clay, and advance sands and gravels The site is located in the approximate E 1/2, NW 1/4 and portions of the V 1/2, SW 1/4 of Section 16, T 23 N, R 5 E and situated between the Cedar River Valley and N.E. 3rd Street to the north. The site is underlaid by deposits resulting from past glacial episodes. The most recent glaciation, the Vashon stade, deposited the majority of the sediments on the site. In general , the soils consist of recessional sand and gravel deposits overlying lodgement till . Beneath the till are dense advance deposits of sand and minor amounts of silt. Beneath the Vashon sediments are undifferentiated preVashon glacial deposits. The side slopes of the northern pit are composed primarily of recessional deposits consisting of compact to dense fine to coarse sand and fine to medium gravel . These deposits were encountered to an approximate elevation of 250 feet in the east slope of the existing northern pit and appear to thicken to the north and northwest. Beneath the recessional deposits is a layer of glacial till consisting of very dense, silty fine sand with little to some gravel . The till was encountered in BH-3 and observed along the base of the eastern slopes and southern portions of the pit. The till has either been eroded or dips steeply to the west and north in the northwest portion of the site. Golder Associates January 11 , 1988 7 873-1161 Boring BH-1 was drilled to an approximate elevation of 195 feet and did not encounter any till . Till was exposed in a drainage ditch constructed along the west side of the central pit area. The surface of the till in this area of the site is around elevation 240 feet. In the eastern side of the central pit area, the top of the till is situated at an approximate elevation of 280 feet. Although not yet confirmed, the till appears to be missing within the central pit area. Several exposures of till were observed in the southern slope facing the Cedar River drainage with the lowest observed outcrop at approximate elevation 190 feet. Located stratigraphically beneath the till and extending to an undetermined depth are Vashon advance sediments consisting of very dense fine to medium sand, fine gravel , and silty fine sand. These deposits are exposed in the floor of the northern pit area; the edges of the southern pit area and probably mantle the surface of the southern portions of the site. Borings BH-3 and BH-5 encountered hard clayey silt and silt at approximate elevations of 205 and 140 feet, respectively. These fine grain units were not penetrated by the respective borings, hence their total thickness could not be determined. As a result, it could not be ascertained whether these silt units represent thin beds within the coarser grain advance sediments or they are the top of a thicker more extensive proglacial lacustrine deposit. PreVashon undifferentiated deposits are exposed in the south facing slope forming the north side of the Cedar River drainage. This unit consists of very dense and hard deposits of older till , lacustrine deposits of silt and clay, and sand and gravel . Based on limited field data, these deposits appear to extend from the base of the slope to an elevation of around 200 feet. None of the exploratory borings penetrated the preVashon deposits. The spatial distribution of the unit, as mapped by Mullineaux (1965) , suggests these deposits may underlie most of the site. The preVashon deposits are competent and maintain near vertical slopes in places. Several slope failures were observed involving the loose organic topsoil and slope debris overlying the preVashon deposits (Figure 1) . These failures appear to have resulted from saturation of the loose organic layer. 5.2 Groundwater Our wells encountered what appears to be a regional groundwater aquifer with water levels approximately two to five feet below the floor of the pit. Our study was completed after a five month drought and these levels are expected to represent a seasonal lower extreme. The pond at the northeast side of the pit is in contact with the groundwater and its surface elevation is consistent with the water levels measured in the monitoring Wells BH-4 and BH-6. During our study, approximately six inches of rainfall was recorded and water levels in the wells were generally on the rise. During field reconnaissance of the site during January 1987, we observed that water levels had risen to the point of causing shallow flooding of most of the pit floor. Reportedly sand and gravel borrow operations have been discontinued at the site as the excavation encountered the groundwater. January 11 , 1988 8 873-1161 It appears the regional groundwater flow is to the west southwest with a local break to the south towards the Cedar River. The overall flow gradient is relatively flat with a value approximating .01 to the west southwest. The pump test2conqucted at BH-4 and BH-6 indicates a transmissivity of 2 x 10" cm'/sec can be assigned to the aquifer in that area. The unconfined aquifer in the base of the pit generally consists of 25 feet of well sorted fine sand near BH-4, BH-5 and BH-6 which becomes coarser and more gravelly near BH-2. The grain size distribution curves are presented in the Appendix. The storm water retention and groundwater recharge system were assessed with data obtained from the pump test and slug test. A discussion of the results will follow in later sections of this report. E . CONCLUSIONS E .1 General Based on the results of our study, we believe the site can generally be developed as planned. Our preliminary assessment of the site hydrogeologic characteristics indicates it is feasible to use a groundwater recharge system to dispose of surface water runoff. However, several critical design parameters including the seasonally high groundwater level and the limitations on discharging to the creek are unknown at this phase. The final design-of the recharge system will require additional exploration and combined civil and hydrological engineering effort. The native soils encountered in our field mapping and exploration borings are generally compact to very dense glacially consolidated soils. The pit and southern bluff slopes in these materials are generally stable at relatively steep inclinations, except where the slope is mantled by loose colluvium. The glacially consolidated soils are adequate to support the proposed Structures with shallow conventional isolated or continuous spread footings. these and other geotechnical related points are discussed in more detail in the following paragraphs. E .2 Storm Water Retention/Recharge System the results of our subsurface exploration and field testing indicate a tom water retention and groundwater recharge system of ponds are technically feasible for this site. However, the feasibility of the torm water recharge system will depend strongly on the following Parameters noted in the subsections below. Golder Associates January 11 , 1988 9 873-1161 6.2.1 The Time of Concentration The time required for the runoff to enter the recharge system is critical to the feasibility of the recharge system. A project design with a high density of structures and pavements will promote rapid storm water runoff and require extremely large ponds to store the runoff unless special controls are included in the design. Practically speaking, we feel some special controls designed to slow runoff will be required to make the project work. These controls may include porous pavement, terraced landscaped areas with dense vegetation, indirect runoff paths and storage features such as upgrade non-recharge ponds or below grade tanks. 6.2.2 The Design Storm or Sequence of Storms The storm event or sequence of storm events is critical in the design of the proposed recharge system. The greater the intensity or duration of the storm used in design calculations, the greater the detention requirements. It is our understanding groundwater recharge systems for storm water disposal in King County are typically designed to store the runoff from a storm with a 25-year return interval and a duration of 24 hours. A 25-year return storm intensity estimated for this site is .13 inches per hour or 3.12 inches in 24 hours based on the "King County Storm Drainage Requirements and Guidelines" prepared from U.S. Weather Bureau Technical Paper #25, 1985. Assuming 70 percent of the site will be covered with structures and pavements and 30 percent of the site is landscaped, we estimate a total of approximately six million gallons of runoff will be produced from the property north of the bluff during a 25-year return storm event. A detention pond capable of storing this quantity of water is equivalent tc approximately 19 acre-feet of storage or a pond approximately 3.2 acres by six feet deep. A design that accounts for a sequence of storms will require significantly greater storage capacity. A back to back sequence of two 1f-year storms, for example, will require approximately a ten million gallon storage capacity or a pond approximately five acres by six feet deep. Pond capacity will likely require a greater capacity than the simple storage of the runoff from one or two storm events. Pond size will also be strongly influenced by the rate of water infiltration or recharge to the groundwater aquifer, as discussed in the following sEction. 6. 2.3 Hydrogeologic Characteristics The hydrogeologic characteristics of the site pertinent to the design of the recharge system include the transmissivity of the soils, the depth to groundwater, thickness of the aquifer, and the gradient of the watertable. Preliminary values for these parameters were obtained from Golder Associates January 11, 1988 10 873-1161 the well testing completed for this study. These parameters are used to Estimate the rate the water in the recharge pond will enter the Groundwater system, the zone of influence or mounding caused by the recharge ponds, and the size of the pond required to store the runoff during the recharging period. Freliminary estimates indicate that although the site has the advantage cf soils that are relatively permeable, it also has the disadvantage of shallow depth to groundwater and a low watertable gradient. As a result, the recharge rate will be relatively moderate. For preliminary planning purposes, we estimate a total pond area of ten to 15 acres may be required to allow recharging of the runoff from a 25- 3ear storm event within an approximate period of a month and a half. this ten- to 15-acre pond is estimated with at least five feet of freeboard above the seasonally high groundwater. A more rapid rate of total recharge will require more pond area or greater heads within the Fond to compensate for the decreasing rate of recharge as head cecreases. E .2.4 Pond Shape, Depth and Configuration the shape and configuration of the recharge ponds will effect the design cf the system by influencing the aerial extent and depth of the Groundwater mound around the recharge ponds. In general , smaller and nore linear shaped ponds with the same total area as the large pond will Faye smaller groundwater mounds. The smaller the mound the lower the risk of the mound rising to the surface and causing flooding or slope instability. As an example, a recharge system that consists of a series cf separate small ponds or a long canal meandering through the cevelopment would be preferable to a large single pond or lake with the same total area. E deep pond built with high berms to maintain a high head for rapid recharge will tend to raise a significant mound in the groundwater and therefore require the surrounding grades to be raised appropriately to avoid flooding. For preliminary planning purposes, we suggest ponds be located at least 800 feet back from the top of the bluff. This setback, which must be reviewed after a second phase of exploration, is intended to minimize the effect of the pond mounding zone on the stability of the bluff. Ponds located too close to the bluff could increase roundwater levels, saturate e s ope sot s, an po en fa y esta lize t e steea s op,.es. 6.2.5 Site Grades The depth to groundwater is very shallow and the groundwater gradient is nearly flat on site. During the wetter winter months of the year, the groundwater levels on site are expected to be at or slightly above the existing pit floor grades (approximate Elevation 230) . Storm water detention ponds recharging to the groundwater are expected to create a Golder Associates Janjary 11, 1988 11 873-1161 localized rise or mounding of the groundwater surface around the recharge pond. Significant filling of the pit floor will be required to prepare the site to accept the recharge. The filling will be required to raise grade sufficiently above the anticipated rise in groundwater to prevent flooding. As a preliminary estimate, we anticipate the grades in the pit floor must be raised as much as ten feet above the seasonal high groundwater levels to create sufficient pond freeboard for runoff storage for the recharge pond to function without flooding the surrounding areas. In general , the fill material used to raise grade in the pit floor should be relatively clean, highly permeable sand and gravel that will promote the recharge of the underlying aquifer. The materials available from the proposed road cut consist of relatively fine grained silts and silty sands that, in general , are not highly permeable. Materials o )tained from other, higher portions of the site are coarser grained and a-e preferred as fill for the pit floor. 6.2.6 Major Storm Emergency Overflow A practical and well designed recharge system must have an emergency over flow option available during at least major storm events and possibly for controlled discharge during other periods. The stream on the west side of the pit and/or a new discharge system constructed to the Cedar River could serve this function if the water quality, capacity, legal , and permitting requirements can be met, It is our understanding that the water rights of the stream exiting the M:Mahon Property are owned by Pacific Land Reclaimation, the operators of the Mt. Olivet Cemetery on the property's west side. The legal aspects and restrictions of the water rights on this stream should be carefully researched as they may have a significant influence on the design of a storm water detention system for the McMahon Property. I addition, most of the property is included within the City of Renton Water Department's "sensitive area" and the extreme southern portion of the property at the base of the bluff is within the "more sensitive area". These "sensitive areas" are within the City of Renton watershed and therefore development and the quality of discharge water tend to be regulated more strictly. E .2.7 The Degree of Maintenance Reliability the recharge ponds will tend to collect fine grained material , leaves, sticks, and trash. These materials will reduce the hydraulic communication to the permeable sands and gravels of the aquifer. To prevent a significant reduction in the hydraulic recharge capacity of the ponds a regular program of pond maintenance will be required. If cleaning of the ponds is expected to be minimal or non-existent, a more conservatively designed (larger) pond is advised. Golder Associates January 11 , 1988 12 873-1161 6.3 Stability of Bluff On the basis of our preliminary visual evaluation, the bluff along the properties southern half appears to be relatively stable in regards to passive or deep seated movements. However, some shallow debris slides and spalling and sloughing of the bluff face were observed. These slides generally involve the top three to five feet of loose surficial soil and vegetation. The sloughing and shallow slides should be expected to continue on the steeper slopes as the outer soil layers ravel and become saturated. The location of the most recent sloughing and slides are shown on Figure 2, Site Geology. A road cut through the bluff soils is technically feasible. However, significant earthwork and subsurface drainage improvements should be anticipated in the slopes both above and below the road. For preliminary planning purposes, we suggest road cut slopes be no steeper than 2H:1V (Horizontal to Vertical ) . The slopes could be steepened if some form of subsurface drainage improvement and erosion protection in addition to revegetation are installed. The erosion protection could include retaining walls, shotcrete, riprap, or minibenches. Subsurface drainage such as french drains or horizontal drains must be incorporated in the road in order to prevent unnecessary saturation and erosion of the loose surficial soils on the slopes. 4 Foundations Shallow conventional spread footings may be used throughout the site if they are founded in the compact to very dense, native sand and gravel . n general , the site soils are suitable to support conventional slab on grade floors. Framed floors may also be used if a vapor barrier is placed over any areas of bare soil and adequate venting is included in the crawlspace. The native sand and gravel is suitable for use as structural fill . We recommend that the sand and gravel be moisture conditioned to within two percent of the optimum moisture content if it is to be used as structural fill . This type of material can typically be placed and compacted in wet weather conditions. 7. RECOMMENDATIONS FOR DESIGN APPROACH 6;e recommend the design of the recharge system use an integrated pproach which balances all of the parameters listed above and optimizes the density and configuration of the development. The balancing nvolves trade offs such as: Building and pavement configuration density will produce more runoff for the storm system than vegetated open space. Adequate runoff controls slow runoff and reduce the required pond storage capacity. Golder Associates Janiary 11 , 1988 13 873-1161 Controlled pond discharge to the creek or the Cedar River reduces the required capacity of the storage ponds. Using a smaller storm or shorter return interval in the design increases the risk of overwhelming the system and causing flooding. The quality of the runoff water increases with longer detention times and pond size. Frequent pond maintenance increases pond efficiency and reduces the required pond size. Deeper ponds are more efficient at discharging the water to the aquifer, but they require the base of the pit to be filled to a greater elevation and they have a less appealing appearance at times of low water. 8. ADDITIONAL STUDIES Additional geotechnical and hydrogeological studies should be completed prior to beginning project final designs. We recommend the additional studies include: Installation of additional wells to confirm aquifer dimensions. A large scale 24 to 48 hour pump test _at another location of the site. A survey of well elevations. Continued monitoring of water levels in the creek and in the wells. A detailed subsurface exploration of the bluff slopes and the locations of all the proposed structures. The exploration should be in the form of a series of backhoe excavated test pits and borings located along the top of the bluff, all along the alignment of the proposed road cut down the bluff, and at all the proposed pond and building locations. 9 . USE OF THIS REPORT This report has been prepared exclusively for the use of Centron Corporation and their consultants for the specific application to this project. The exploration has been performed in general accordance with locally accepted geotechnical engineering practice to provide Golder Associates Jaruary 11, 1988 14 873-1161 Preliminary information for the area explored. We recommend additional ceotechnical and hydrological studies be completed prior to beginning Eroject final designs. Sincerely, COLDER ASSOCIATES, INC. DAB Craig C. LaVielle Senior Engineer 7 D Lp, Coug17J. Morell Associate CJM/CCL/111/846 Attachments cc: Mr. Bruce Dodds - Dodds Engineers, Inc. (Bellevue, Washington) Golder Associates FIGURES Golder Associates 143 4 . .----.• -r.-.;•:±..._-•••.'" ----- - . •-• joo- ...... r II 1 - •25-,z, •••••vvr . !.. LI' 2 it-•rf L sr.I ir 1/4(. 30212.....—-.... . \''''' <.'..--* .....:2S0_::...:-•—290 '. i • i i • •‘••• I!'', 'i: 1 t1/2.,.7::',..1 40 ,,,. . i --/;-)Le.,..j,i;..f v • 4r• 1"\-.. N.; • ••••.„... At'- i. i A 260-• 40 X 1../ ..010“.8.s.l BH-3 r,761 I • •-: , it i • G010.0,000 . 4. . C10 •4:311 f. 4%, ....,.L i 1 '. . A. 7fe ./--i 3 41,• .-- : I i It . 41-- I r • V 4:avr. t OvrAt 1 f i 4'S ..1,iL 'I !I --;,/..u.... i I I ', 1.7 1W ' " • SITEk ----,, ..., 1 i,4, 1c,A\ •• •••••••I I, l'....1 i ',.,;. 1_ Cla0.• . 1• 1;— 77sa \. 1 I 1' isi I 4.6, BH-6 !!1-.:? 4/ I+ t‘ •Ik .'•`\-.\ ,.\ w6 1 i 1. ;It, J. 0 11 i Ir''' \ .s\,' -''\ • BH-4 .: ' 1 ...J 1itS°.. s.;....."..-7) H-• B5 v 1 I ," Uirii• sT i 1-•-. b,...„. 1 I li . s... s'0!.Ammo .....,,. , 74.6-•-•t•\. \'‘\‘ ''. ' 1 .I iF: s.000.0 IV .frt ,..,.. a 7 :: 1:.:. ',.. 65•1 i I. ‘ 0 2000 4000 Si f t, ,,,y, • ,....‘ "‘, N.\. Ne •t SCALE IN FEET VICINITY MAP 1A,..--- \ , \itt• , A ..\ \\-... -------.Qvt — ----—--- 2230 300 Q V r - ••• 1` •t-:---. ---7— --1—. •- • .29o. —..- 77!•:::::;=. e I 77.,,,:?( Qvt .7•: N ', '. \ \ Ova \\•,.0,...*,..:ZN z;..:0'.. ' \.....*: ...\*. VA zs.-,.-. ——, Ova *s;;-•'.--;"7.75*--`!-,2• A...;0•.^.-', 1 r.•••• . .,1 ,.r la • 1• 4-'..---7--' ---t-14/ 4 e., if.•`.'320.--- i '- °' \ s.N f o II i: :-: • 1, . , • . ...f k', ii E .i ! , 1 .ts 320.. j s•:::.-". l'''''' :\ s ' ;7:4,--•• .• / fr-- -----1 e'2 \ ••,...s...,. .:,.,,:," , : Opv 0"'•". ... '. 7: it 0.-7.1—.7 •:( \•-1:. ••-, :14\ f•••*" `..<,:•••;"•••...- ' . ... ,: i 1 M• • ,i.,\ s• .....", .."-•• (,---.s. f Q /-; .li r . . -0Vt .pp.tr•-• •-• ..:;...--_—___,.. . ,/- .v---....„!,.itt.•--. •-.....-• uls -011*---z. 0 . -• : -- :- ,-.4..-,-'),.....-..f2- /2 24z-,; •;tr.4. 1. ..;....7.:.;/-e•::•::.;;,.0-7-.„....;...i.i.::.,,...... re. 1".......••;........,,,./..1;0. •,7.1%P.••. • . Oa i i"•••••ta° --180::..1'N7-cl "? -:•i•-;':!-'(‘. z-•--z--,. 1 . 1---ye:',A,„-:,,, Oa. -/ 7 4 r;.- , •• • -,c4, .... ___.• /, Ga- , ..---7----'•" 7-7F•4',•:::.. -......--,.- ... ...._-----r-_...SITE PLAN ilLEGEND 4,BH-1 Borehole Number and mm'mm Property Boundary Approximate Location Geologic Contact Unpaved Road Qa - Alluvium Powerline Tower r 1 il Qls - Landslide Deposit 4= 4 Powerline Poles Qvr - Recessional Outwash Schematic Cross-Section Qvt - Glacial Till Creek Ova - Advance Outwash CD Pond Opv - Older Glacial Drift FIGURE1 ag# Truck Scale and Scale Houses VICINITY MAP, 0 400 800 OUTCROP MAP AND SITE PLAN SCALE IN FEET CENTRON I...Ku/cr..°373-1161 cy,c mo 6399 Cat 1/8/88 au... SL soogoveo RU Golder Associates A Qvr Qvt z Qva SI v Qva a SE QvI? t tc LEGEND Qa - Alluvium Qvr - Recessional Outwash Qvt - Glacial Till 3E(Qva - Advance Outwash Qvl - Lacustrine Deposits Qpv - Older Glacial Drift Interpreted Geologic Contact Q Water Table i! Match Line FIGURE 2 SCHEMATIC CROSS—SECTIONS A—A', B—B' CENTRON Golder Associates APPENDIX Golder Associates Figure RECORD OF BOREHOLE 1 Page 1 of 3 LOCATION: See Figure DATUM: MSL DATE:11/3/37 - 11/5/87 AMPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test A 'N' Blows per foot co cc w W 10 20 301 410 PI EZOM E T E R ELEVN DESCRIPTION 0 CM 0. F-INSTALLATION DEPTH 7 = L Water Content, percent 0 z m o I • Steel Monument a) Wp Wn WL Casing 273 0 ti7 0 Compact, brown, gravelly, fine SP to medium SAND, trace silt Cement U 270.5 2.5 Very dense, brown, fine SAND, SP little to some silt, trace SM 8 gravel 1 18 - - 41' 268.0 38 _ 5 _ 5.0 Dense, brown, fine to medium SP 2 1 A. SAND, trace silt with occasion- SM 10 - al iron staining and thin 33 _ - LI layers I1/4-1/8 ) of very 18 dense, brown, silty, fine SAND, 3 35 - . A trace to little clay (SM) 41 - - becoming very dense at 7.0 ft. 14 - 10 4 24 34 - 34 5 50 - - A 21 - 15 _ 6 55° A. o \\ 7 50 V 20- Bentonite Slurry 20 _ - 8 50 little to some gravel, coarser SAND 50- - A 30- 10 6° - - A REMARKS: Gi-oundwater encountered at a depth of 48.5 feet. Standard Penetration Test Waiter level in piezometer at a depth of 52.4 feet on 11-11-87. VERTICAL S:ALE: CENTRON 1 IN. TO 5 FT. f Associates J08I873-1181 Figure RECORD OF BOREHOLE 1 page 2 of 3 LOCATION: Soe Figure DATUM:MSL DATE: 11/3/87-11/5/87 AMPLER HAMMER WEIGHT: 140 LB..DaOP 30 IN.BORING METHOD: HOLLOW STEM AUGER I SOIL PROFILE SAMPLES Standard Penetration Test F- N' Blows per foot co co 2 10 201 30i 40 PIEZOMETERwIlio _ELEVN DESCRIPTION U 1 >- 3 i Water Content. percent INSTALLATION DEPTH a) D 1,... O ui C.) Z Jm o I • I CD Wp Wn WL D 237.5 35 1 35.5 Very dense, brown, fine to SP medium SAND, trace silt, trace Bentonite Slurry gravel 29 11 50 - - A 6" - -1 232.5 40- 40.5 Very dense, brown-grey, fine to SP medium tc coarse SAND, trace silt, little to some gravel 12 6 -A 227.5 45 - 45.5 Very den :e, brown-grey, fine to SP medium SAND, trace silt i 30 - 13 50 I. \ 5" 222.7 50- 50.3 Very dense, grey-brown, gravelly, SP fine to rredium to coarse SAND, trace silt 11-11-87 0 14 4"^ 52.4 55- 29 15 50 ` E A 4" _ 1212.5 60 - 60.5 Very dense, grey-brown, medium SP to coarse SAND and fine gravel, Silica Sand trace silt 11 _ - J - 16 50 - r A 6" 65- 17 1 4 _ -Slotted Zone 30 T nCMARKS: Standard Penetration Test VERTICAL SCALE: CENTRON 1 IN. TO 5 FT. 0 Golder Associates JOB 873-1161 Figur• RECORD OF BOREHOLE 1 Peg• 3 of 3 LOCATION: See Figure DATUM: MSL DATE:11/3/87-11/5/87 MPLER HAMMER WEIGHT: 140 LB..DAOP 30 IN.BORING METHOD: HOLLOWAUGEROW SOL. PROFILE SAMPLES Standard Penetration Test A 'N' Blows per foot 03 00 CC o ` L 10 20 30 40 W I PIEZOMETER ELEVN J a INSTALLATION DESCRIPTION U M >- 3: a Water Content. percent DEPTH CO = F- O w U z m a f • cn Wp Wn WI_ 70 202.0 ____. Slotted Zone 71.0 Very dense„ grey-brown, fine GP GRAVEL. little to same coarse to 17 - medium sani, trace silt 18 50 ' A p, 5„ - Silica Sand 75 R. — 12 Cuttings 194.0 19 17 -I A r 10 50 79.0 Bottom of hole at 79.0' 50 — 80 85 - 90- 95- 100— REMARKS: Standard Penetration Test VERTICAL SCALE: CENTRON 1 IN. TO 5 FT. JOB* 873-1161 RECORD OF BOREHOLE 2 Page 1 Pig 1 of 1 LOCATION: Sell Figure DATUM: MSL DATE: 10/29/87 MPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test FA 'N' Blows per toot coco cc m a 10 20 30 40 ELEVN m I" m = I PIEZOMETER CESCRIPTION 0 M } 3 1-INSTALLATION el- A Water Content, percentDEPTHco1._ p 0 Z m f • Steel Monumentco Wp Wn WL Casing 229.5 0 l 0 Compact, brown, medium to coarse SP 1 Cement t-ts, ;" SAND and gravel, trace silt Bentonite Slurry dense— ——IhI Ig 1 35 Z 11-11-87 3.4 compact 14 5 2 12 25 T1\`3 15 A. L20.0 13 uj,5 >lense,ro n,rtn oe me m 1 Sp 13 10 c LO_SA lQ tracL.ailt_— 0.5 Dense, brown, gravelly, coarse SP 15 A N SAND with 'nterlayers of dense, GP 32 brown, fine to medium SAND, 10 Il trace silt and dense, brown, 13 Silica Sand rsandyGRAVEL 21 12 15 - 6 16 A 39 17 7 13 k•'' - 18 20- Slotted Zone ;.-..:: II 18 06.0 8 20 3.5 Very dense, brown, fine to SP 50 medium SAND, trace siltII 3' 25- 12 Caving ` // l- 0.5 ill 40 50 y 1 I l II 3.0 Bottom of dole at 29.0' 5' 30— REMARKS: Groundwater encountered at a depth of 4.5 feet. Standard Penetration Test Water level in piezometer at a depth of 3.4 feet on 11-11-87. VERTICAL SCALE: CENTRON 1 I N. TO 5 F T. o f Associates J O 8 8 T 3-1181 Figure jRECORDOFBOREHOLE3Page1of3 LOCATION: Sou Figure DATUM:MSL DATE: 10/29/87-11/3/87 MPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test co 13 A 'N' Blows per foot 10 20 30 40 w w I L I I PIEZOMETER ELEVN CESCRIPTION 0 M } i-INSTALLATION DEPTH co D . O a Water Content. percent 0 z m o f • 1 Steel Monument a)Wp Wn WL Casing 300.0 0 11 Y'-' 0 Dense, brolm, gravelly, fine to SP I i medium SANE, trace silt toadense Cement brown, med urn to coarse SAND, trace gravel 45 1 32 ` ii 19 _ _ 10 - 5 - 2 17 _ " 21 y 10 3 17 A 21 - 14 - 10 - I 4 16 _ i s 17 - 7 _ 1517 12 15 - 6 18 _ 15 _ " v 10 _ 7 16 1. cZ, 18 - 20-" N 15 8 22 A 28 - very dense 2 5 y Benetonite Slurry 18 _ " 9 32 A 40 269.5 30- 30.5 Dense, bro,rn, fine to medium SP 111SAND, trace silt f 15 _ 19 - - 10 16 REIAARKS: Gourdwater encountered at depths of 51, 56, and 76 feet. Standard Penetration Test Water level in piezometer at a depth of 73.3 feet on 11-11-87. VERTICAL SCALE: CENTRON I IN. TO 5 FT. gnerAssociates JOBI573-1181 Figure REGARD OF BOREHOLE 3 Page 2 of 3 OCATION: See Figure DATUM:MSL DATE:10/29/87-11/3/87 AMPLER HAMMER WEIGHT: 140 LB..OROP 30 IN. BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test N' Blows per foot cc m ' L 10 20 40 w i 30 L PIEZOMETER ELEVN DESCRIPTION v 7 r 3: a Water Content. percent INSTALLATION DEPTH co D 1._ O IUzmoI cn Wp Wn WL 0 35 1 very dense 22 1\\\\ 11 24 260.5 32 - 139.5 Alternating layers of compact, MI_40- brown, silty, clayey. fine SAND SM and compa,:t, blue-grey, clayey SILT 4 Bentonite Slurry—.12 5 - 5 254.5 45 -+ 45.5 Alternating layers of very dense, SP brown, silty fine SAND, trace SM clay and very dense, brown, fine 1 to medium SAND, trace silt 22 _ - - 13 50 6" 50- 24 14 50 - " A 6" - - 5 5--+ 50 _ " A15 237.5 62.5 Very dense, grey, silty, fine SM 16 50 - - SAND,trace to little clay with 4" - occasional gravel (Till) 50 - - 17 3" _ - A Silica Sand: REMARKS: Standard Penetration Test VERTICAL SCALE: Associates CENTRON 1 Itd Trl IS CT 1 Les Jr R# 871-1161 Figure RECORD OF BOREHOLE 3 Page 3 of 3 LOCATION: S,oe Figure DATUM: MSL DATE: 10/29/87-1113/87 AMPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOO: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test A 'N' Blows per foot cc co u_ 10 20 30 40 ELEVN ui w m = r PIEZOMETER DESCRIPTION V CO 1- INSTALLAT!ON DEPTH D 1- O w Water Content, percent z Jm' n I • f Cl) Wp Wn WLD 70 50 18 4" - - 11-11-87A 7 75 - 73.3 • 224.0 76.0 Very dense, brown, silty, fine to medium SAND (SP) and very I:•.• dense, brown-grey sandy SILT, 50 _ t:..: trace clay (ML) 19 6„ 220.0 Y 80.0 Very dene, grey, fine to 8 0 ~ medium S/ND (SP) Silica Sand-----:::, I 32 I Very dense, brown, silty, fine Z0 50 A SAND, trace clay (SM) 5" - - 85 30 21 40 - - 41 - - 209.0 90 Slotted Zone r 91.0 Very dens', grey, silty fine SAND (SM) I 30 22 42 " - 50 5" 204.5 95-- 95.5 Very dens', grey, clayey SILT, trace fin' sand (ML) with occasiona laminae of grey fine 30 201.0 SAND (SP) 23 23 - A 47 99.0 Bottom of hole at 99.0' 100- REMARKS: Standard Penetration Test VERTICAL SCALE: CENTRON I IN. TO 5 FT. C7 J08# 573-1161 Figure RECORD OF BOREHOLE 4 Page 1 of 1 LOCATION: Si. Figure DATUM: MSL DATE: 10/28/8 SAMPLER HAMMER WEIGHT: 140 LB..DROP 30 IN. BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test A 'N' Blows per foot co p- a, cc m `L 10 20 ELEVN w Ili - i 30`40 PIEZOMETER DESCRIPTION coUINSTALLATION a Water Content, percentDEPTHmMF. O w Z con I • Steel Monument m Wp Wn WL Casing 231.0 0 3C 0 0 Loose, Drown, fine to medium SAND, SP Cement" = 1.0 grace silt and trace gravelt; Compact, brown, fine SAND, SP 4 - trace <ilt 1 10 - - Bentonite Slurry 3 - 5 -11-11-87 2 3 _ AC. 5.0 dense 1 9 - - 3 13 - a A g - 10 - c\4 15 - T\ 19 N very dense 15 6 20 32 - - A dense 5 - 15 -r 6 13 _ _ A 21 Very dense, tan, clayey SILT ML 13 1. 212.5 \ 7 15 - - A 18.5 Dense, crown, fine to medium SP 50 SAND, trace silt 5, - 20- Slotted Zone 15 8 50 - - A 5N - - 205.5 2 5 - Silica Sand 25.5 Blue-grey, silty.CLAY, little CH fine sand 203.5 27.5 Bottom of hole at 27.5' 30- REMARKS: Groundwater encountered at a depth of 6.0 feet. Standard Penetration Test Water level in piezometer at a depth of 5.0 feet on 11-11-87. VERTICAL SCALE:ign Golder es CENTRON 1 IN. TO 5 FT. 0JOBI873-1181 RECORD OF BOREHOLE 5 Figure Page 1 of 3 LOCATION: :e• Fiput• DATUM: MSL DATE:11/5/87-11/6/87 SAMPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Teat A 'N' Blows per foot CO i- CO S m 0. 10 20 30 40 W W I i I PIEZOMETER ELEVN DESCRIPTION U 3 I-INSTALLATION a Water Content. percentDEPTHo3MF- p u.1 lUzmnI 07 Wp Wn WLm 231.0 0 0 Compact, brown, fine SAND, SP trace silt 5 — dense 10 — very dense 15 — 20— 2 _ -0 1 25 - - 36 — - 205.5 25— 25.5 Alternating layers of very dense SP grey, silty fine SAND, trace SM clay, trace gravel, very dense, 21 blue-grey, silty fine SAND, 2 34 - - A little clay and very dense,46 - - brown, fine SAND, trace silt 30— 3 -2 3 50 - - A 6" - - EMAAKS: Standarn Penetration Test VERTICAL SCALE: f Associates CENTRON 1 IN. TO 5 F a 108I873-1181 Flqure RECORD OF BOREHOLE 5 Page 2 of 3 LOCATION: See Figure DATUM:MSL DATE:11/5/87-11/5/87 SAMPLER HAMMER WEIGHT: 140 LB..OROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test A co i-PC' Blows per foot cn cc co10 20 30 40 ELEVN m W w i 1 PIEZOMETER DESCRIPTION vM r 1,.. Water Content, percent INSTALLATION DEPTH co O w U z m o I • I a Wp Wn WL 195.5 35 35.5 Very dense, dark grey-brown, SP fine to medium SAND, trace silt with occasional laminae of iron stained fine SAND 4 ' 50 - 3' A. 40- 5 50 - - 6' _ " 45 - 30 6 50 - 4' - - 50- 178.5 52.5 Alternating Tayers of very dense, SP 7 50 - , A grey, silty,fine SAND, trace to SM 2' little :lay, very dense, brown, silty, fine SAND, and very 5 5- dense, brown, fine SAND, trace silt 20 _ 8 25 4. 40 - " 6 0 - 21 9 31 - - 4 41 - - 65- 10 _ 10 25 A• 45 - - REMARKS: Standard Penetration Test VERTICAL SCALE: CsOf Associates CENTRON 1 IN. TO 5 FT. oJOB* 873-1161 Figure RECORD OF BOREHOLE 5 Page 3 of 3 LOCATION: Se• Figure DATUM: MSL DATE:11/5/87-11/6/87 AMPLER HAMMER WEIGHT: 140 LB..DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Pen•tration Test A 'N' Blows per foot 01 1— CO co 10 20 30 40 u itii PIEZOMETER ELEVN DESCRIPTION 0 CO >- 3 INSTALLATION O w Water Content. percent DEPTH H 0 z m a I a) Wp Wn WL 70 25 11 50 - - A 4" 155.5 75 — 75.5 Very dense, grey, fine SAND SM and SILT, trace clay 17 12 50 - A 6" - 80 20 - A1350 5, _ 85 - 30 _ - A1450 5" 140.5 90- 90.b Very dense, grey SILT, little SM sand, l. ttle clay (ML) 30 - 137.5 15 50 _ A. 93.5 Bottom of hole at 93.5' 6" - 95— 10 0— REMARKS: Standard Penetration Test VERTICAL SCALE: CENTRON 1 IN. TO 5 FT. 0 f Associates JOBS 8 7 3-1181 Figure RECORD OF BOREHOLE 6 Page 1 of 1 LOCATION: See Figure DATUM: MSL DATE: 11/6/87 SAMPLER I-AMMER WEIGHT: 140 LB.,DROP 30 IN.BORING METHOD: HOLLOW STEM AUGER SOIL PROFILE SAMPLES Standard Penetration Test A 'N' Blows per foot cc co w 10 20 30 40 ELEVN w w m = PIEZOMETER DESCRI PTION U as a INSTALLATION DEPTH CO n F- O ui Water Content, percent J w a 0 Z ca o Wp Wn VI teel Monument 231.0 f Casing 0 Compac':, brown, fine SAND, SP O 1 Cement i trace silt aC 'I Bentcnite Slurry O 3 Silica Sand 5 — 1'1-11-87 Q cv• •: 5.0 - is.-. dense r= 10 j': r Slotted Zone very dense 15 -, a 20-- J 206.0 25.0 Bottom if hole at 25.0' 25- 30- REMARKS: Witter level in piezometer at a depth of 5.0 feet on 11-11-87. Standard Penetration Test VERTICAL SCALE: 6), ( fAssociates CENTRON 1 IN. TO 5 FT. j JO8#873-1161 US Standard Sieve Sizes s 3" 2"3/4" 3/8" 4 10 20 40 60 100 200 I iv I I n 11 i 1 I I IIIII 80 III 11 1111 I 111 i_1111 1 III ! 0 r 701111111111_i'I! U11I111 IEN u c" 60 I 'i 1uu1111111111' 03 A 50 9111u111____111111 1 m a) 1 1— 1 Z40 1 i1111iN -n u 3oI111 40 C a20 1 I i I111 ll 11 liallir 10 11 p Ell 11111 11k C I11111111111111 I 0 1- 1 1 I _ ! I a, O 100 10 1.0 0.1 0.01 0.001 Z Grain Size in millimeters cp Cobbles Gravel Sand Fines Coarse 1 Fine Coarse] Medium l Fine Silt or Clay 00 Boring No. Elev. or Depth Wn WL Wp Ip Description or Classification a BH-4 18 22.5' - 24.0' Brown, fine SAND, little coarse gravel, little silt (SP-SM) DBH-2 #5 12.5' - 14.0' Brown, fine to coarse SAND and fine gravel , trace silt (SP) BH-4 #2 5.0' - 6.5' Brown, fine SAND, little silt (SP-SM) BII-2 M9 27.5' - 29.0' Brown, fine SAND, little silt, trace gravel (SP-SM) d CD in 01 — Pump on 1 0 -15 e R 0.1 - 0.3 - 0.5 - a) a) I -0.7 N 0 TO -0.9 - 1.1 - p 0 1.3 - 0 1.5 - Pump off 1.7 I p O 1.9 1 1 1 1 1 1 1 1 1 I 1 1 I 1 r 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 Log t (seconds) FIGURE BAIL TEST: BH-2 Drawdown (10 gpm) / Recovery CENTRON Pno,EcINO 873-1161-000 OwO NO 8205 DIE 1/11/88 OHAwII PT APPROVED RU Golder Associates o 0.1 - Pump on 7.6 gpm) 0.2 — 0.3 -~ 0 a) a) -0.4 -- 4 U C -0.5 -- 0 cn -0.6 — 0 CJ 0.7 — 0 0.8 — 0 glI giro 0.9 rs 1111 Note: BH-4 is 10 feet south of BH-6 Pump off 1 0.8 0.4 0 0.4 0.8 1.2 1.6 2 2.4 Log t (minutes) FIGURE PUMP TEST: OBSERVATION WELL, BH-4 Drawdown / Recovery C EN T RON PROJECT so 873-1161-000 owc so 8206 OME 1/11/88 DRAWN PT APPROvIO RU Golder Associates o I Pump on 0.5 — 1 .- 1.5 -- a) En c 2 o 0 cti 2.5 — 3 — C] Dolma' ,;11,;4i; IIIl11L I I II . III I!10•or ,'1 3.5 — 1 Pump off a r I r 1 r r I r I r 1 0.8 0,4 0 0.4 0.8 1.2 1.6 2 2.4 2.8 Log t (minutes) FIGURE PUMP TEST: PUMPED WELL, BH-6 Drawdown (7.6 gpm) / Recovery CENTRON PROJECT NO 873-1161-000 owo ND 8207 D.,E 1/11/88 OHAWN PT APPROVED RU Golder Associates i 1 i...4.......Y...;.:.>.;.>.;.>.S;..:..;.;.:..';..;O......R....I...ICSS..............<...'.. RAE LULA L Eh E 41 A A<P E . -N : CEDAR CREST MAN[1FA Ti R DIMODULAR HOME ••COMMUNITY OUR JOB NO. 51 OCTOBER 12, 194994 P G ' REVISED NOVEMBER 4, 1994 (TMN) Q' of W„ B glikilkl As 7 1 Al • 23975 U Pre are BP Y I Exn!Es 6'7 - 9 s BARGHAUSEN CONSULTING ENGINEERS, INC. 18215 72ND AVENUE SOUTH KENT, WASHINGTON 98032 206) 251 -6222 Q7¢( HQ S 2 i _ = CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENTAL SERVICES TABLE OF CONTENTS 1. TECHNICAL INFORMATION REPORT WORKSHEET AND PROJECT NARRATIVE 2. DESCRIPTION OF EXISTING AND PROPOSED ON-SITE DRAINAGE FEATURES 3. ANALYSIS OF CORE REQUIREMENT NOS. 1 THROUGH 5 FROM KING COUNTY SURFACE WATER MANUAL 4. ANALYSIS OF SPECIAL REQUIREMENTS FROM KING COUNTY SURFACE WATER MANUAL 5. PRELIMINARY RETENTION AND WET POND SIZING CALCULATIONS Page 1 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART 1 PROJECT OWNER AND PART 2 PROJECT LOCATION PROJECT ENGINEER AND DESCRIPTION e Cedsr CProjectOwner . `h c_ _ _ Project Name Address Pam• S.yc c.8 C 513Ti c,//a Location 575- -Zpp0 TownshipPhone s Project Engineer ,P6riA R Range Section /E se /7 Company Doi Project Size /33 '«• AC Address Phone /82'/S 72 r• .1: /64,7(Upstream Drainage Basin Size /4 a... AC 26"/-6 7.7..A. TYPE OF PERMIT APPUCATION PART 4 OTHER PERMITS I .y Subdivision 0 DOF/G HPA Shoreline Management Short Subdivision 0 COE 404 0 Rockery tie Grading n DOE Dam Safety n Structural Vaults El Commercial 0 FEMA Floodplain 0 Other n Other COE Wetlands 0 HPA PART 5 SITE COMMUNITY AND DRAINAGE BASIN Community Drainage Basin Cedar- eZr./es-- PART 6 SITE CHARACTERISTICS El River 0 Floodplain 0 Stream 0 Wetlands 0 Critical Stream Reach 0 Seeps/Springs 0 Depressions/Swales Q High Groundwater Table 0 Lake El Groundwater Recharge 0 Steep Slopes 0 C.ther El Lakeside/Erosion Hazard PART 7 SOILS Soil Tyw Slopes Erosion Potential Erosive Velocities G dlr t`4 EzfG e !r., As w LJ Additional Sheets Attatched 1/90 Page 2 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET. PART 8 0= ELOPMENT LIMITATIONS REFEI IENCE LIMITATION/SITE CONSTRAINT I 1 Ch.4-Downstream Analysis IJ IJ I I I Additional Sheets Attatched PART 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTION Sedimentation Facilities 4Z3 Stabilize Exposed Surface Stabiliz ed Construction Entrance Remove and Restore Temporary ESC Facilities Perime ter Runoff Control Clean and Remove All Silt and Debris I I Clearirg and Grading Restrictions Ensure Operation of Permanent Facilities I I Cover Practices I 1 Flag Limits of NGPES Constriction Sequence I I Other I I Other PART 10 SURFACE WATER SYSTEM 0 Grass Lined Channel LI Tank g Infiltration Method of alysis CI Pipe System 11 Vault I I Depression t El Open Channel I 1 Energy Dissapator LI Row Dispersal Compensation/Mitigation LI Dry Pond I I Wetland I 1 Waiver of Eliminated Site Storage Wet Pond I I Stream I I Regional Detention Brief Description of System Operation $'br , c a7`tss a f s i / 4 /^- '/ 7'fv4 L.147 fa4//- 1-1 6.Api1L-/A 0N4.1 . Facility Rela led Site Limitations f I 1 Additional Sheets Attatched Reference Facility Limitation PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS May require special structural review) n Drainage Easement I 1 Cast in 'lace Vault 0 Other I 1 Access Easement I I Retaining Wall I Native Growth Protection Easement I Rocker,>4'High I 1 Tract I I Structui al on Steep Slope I Other errir GNATURE OF PROFESSIONAL ENGINEER • I or a civil engineer under my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attatchment i. To the best of my knowledge the information provided here is accuato. sb"'av`• 1/90 1. TECHNICAL INFORMATION REPORT WORKSHEET AND PROJECT NARRATIVE The proposed project is located on a 133-acre site in east Renton. While approximately 96 of the acres will be developed as a 400 site manufactured/modular home community, approximately 30 acres will remain native, and 7 acres located at the southwest corner of the site will be developed in the future as 20 single family homes in conjunction with the adjacent property to the west. Vehicular access will be via N.E. 3rd Street which runs along the northern boundary of the property. The site is a gravel pit which has been mined of most of the useful coarse gravel materials. The underlying foundation material is primarily sand which allows for good infiltration of surface water. Stormwater from the proposed paved surfaces and roofs will be controlled through the use of a series of retention/infiltration ponds. Stormwater will pass through three-cell wet ponds for water quality enhancement prior to discharge into the retention/infiltration ponds. Page 1 5149.002 [HPG/kr/sdc] 2. DESCRIPTION OF EXISTING AND PROPOSED ON-SITE DRAINAGE FEATURES There is a small upstream basin to the northeast of the proposed project site of approximately 17 acres. The stormwater from this site infiltrates into the ground. A majority of the stormwater from the project site also infiltrates into the ground. The remainder is conveyed, via manmade channels which were created during the previous gravel mining operation, to a water control structure. This structure is located approximately 500 feet south of the northwest corner of the site. Water from this structure flows through a 12-inch buried pipe to an open basin just outside the extreme northwest corner of the site. The water from this basin overflows into a 48-inch diameter corrugated metal pipe at roughly a 5 percent slope for a distance of approximately 113 feet. From that point, it discharges into a drainage channel traveling in a westerly direction. This drainage channel is extremely well defined, heavily vegetated, and the water travels approximately 300 feet where it discharges into an open pond approximately 100 feet by 50 feet. This pond is approximately 3 to 5 feet deep and is located along the south margin of N.E. 3rd Street, and east of Blaine Avenue N.E, near the entrance into the Mount Olivet Cemetery. From this pond, the water enters into a pipe system that runs along the southern margin of N.E. 3rd Street, and then travels westerly approximately 1,200 feet eventually discharging into a system near I-405. Along this course there are no noticeable erosion or flooding problems. The methodology in handling the developed stormwater from the pavement areas, as well as the roofs and yards, will utilize combination of wet ponds and retention/infiltration ponds. There are three facilities which are conceptually shown in the attached drainage map located within this drainage report. All of the surface water will be routed through a wet pond facility and then discharged directly into a retention/infiltration pond. Detailed subsurface soils investigation has been conducted, and the information has been incorporated in the design of the retention/infiltration ponds (see Geoengineers report, dated October 24, 1994). All of the pond facilities are designed in accordance with the King Page 2 5149.002 [HPG/kr/sdc] County Surface Water Design Manual. The infiltration ponds are sized to accommodate a 100-year storm event; in addition, an emergency overflow spillway is provided. One hundred percent (100%) of the stormwater is discharged via the infiltration ponds, and consequently, no storm related discharge is anticipated off site. The soils subsurface analysis shows that this water migrates to the west in the direction of the downstream system described above. If an emergency overflow ever occurs from the proposed system, the direction of the flow will also be to the west. Page 3 5149.002 [HPG/kr/sdc] 3. ANALYSIS OF CORE REQUIREMENT NOS. 1 THROUGH 5 FROM KING COUNTY SURFACE WATER MANUAL The following core requirements required by the King County Storm Water Manual will be met by the design of this system. These include the following: 1. Discharge at Natural Location. This project will discharge at its natural location via subsurface soils. The water quality enhancement/disposal facility utilizes biofiltration wet ponds and disposal by infiltration. This system will be designed by qualified hydrological and civil engineers. The system as designed will closely replicate the existing predevelopment conditions. 2. Off-Site Analysis. As stated in the project narrative, the downstream system from this project has been analyzed. In the event of any malfunction of the disposal facility, emergency overflow spillways will be designed in conformance with the King County manual and will discharge at the natural location. 3. Runoff Control. The retention/infiltration ponds and wet ponds sized for this project are in conformance with King County's manual. The preliminary calculations are enclosed within this report. 4. Conveyance System. All the conveyance systems to be constructed within this project will be designed in conformance with the King County Storm Manual. These will be designed to the 25-year storm event. A backwater pipe sizing analysis will be done as part of the final design for construction permits. Page 4 5149.002 [HPG/kr/sdc) 5. Erosion/Sedimentation Control Plan. A detailed erosion and sedimentation control plan is being submitted as part of the grading permit application. Page 5 5149.002 [HPG/kr/sdc] 4. ANALYSIS OF SPECIAL REQUIREMENTS The fmal design of this project will be in detailed compliance with all of the special requirements. The special requirements which might apply to this project include the following: Special Requirement No. 2, Compliance with Existing Master Drainage Plan Special Requirement No. 5, Special Water Quality Controls Special Requirement No. 12, Soils Analysis and Report The above-mentioned special requirements will be further analyzed, if necessary, during the fmal design for construction permits. Analysis of these items has already been commenced for use in the preliminary design of the drainage facilities. Page 6 5149.002 [HPG/kr/sdc] 5. PRELIMINARY RETENTION AND WET POND SIZING CALCULATIONS The enclosed are calculations used for the sizing of the retention/infiltration ponds and wet pond facilities for this project. The biofiltration wet ponds proposed for this project will be used in lieu of biofiltration swales to provide better water quality control. The calculations showing the methodology, sizing and exact volume required for each of the ponds are enclosed within this report. Page 7 5149.002 [HPG/kr/sdc] Storm Detention Calculations Segale Mobile Home Park BCE Job#5149 T. Nelson 10-4-94 NORTH BASIN (Pond 1) Total Basin Area = 51.25 ac. = 205 DU /51.25 ac. = 4.0 DU/ac. = 42% impervious area Impervious Area = 21.53 ac Pervious Area = 29.72 ac. Existing Conditions: 51.25 ac. CN 68 SOUTH BASIN (Pond 3A and 3B w/ overflow to Pond 2) Total Basin Area = 45.0 ac. Mobile Home Area = 208 DU / 38 ac. = 5.5 DU/ac. = 50% impervious area Impervious Area = 19.0 ac. Pervious Area = 19.0 ac. Future Development Area = 7.0.ac. 4.5 DU/ac. = 46% impervious area Impervious Area = 3.22 ac. Pervious Area = 3.78 ac. TOTALS Ex conditions: 45.0 ac c CN 68 Proposed conditions: 22.22 ac. c CN 98 22.78 ac. © CN68 POND DATA Infiltration Rate = 4 in/hr=0.00009259 ft/sec Pond Bottom Areas (sf) Discharge rate (ft/sec) 1 28,700 2.66 2B 3,250 0.30 3A + 3B 12,826 1.19 WET POND DATA Pond Impervious Area (sf) Wet Pond Area Req'd (sf) 1.0% of Impervious Area) 1 952,657 9,527 3 967,903 9,679 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL • FIGURE 3.5.1C 2-YEAR 24-HOUR ISOPLUVIALS a 4' ' 0 '., .y j-9 lifi 14 1pilr'E i a l'14 s;. . - ;_,, Iikk1441(‘10 1 ‘ . 41i ii -,i 1 ir _11.. ', ---- - 44_—...aw - :,w EE ei N. N , ,_(,,,,iv•X Eta .,i i 0.4 i oit__ pjti:,,,, ,,,,..40,...... Ni\---Ett.4 --._ 4151%111114 A.4,-401,9A / ' I tot . 2.Q _ Altitikt--.-hi ' AirlilkidL744111M,44Ar N q 11Z,ttlitr r/ ire . ml!ii Ie. vitt - 6%44.t ) 'IF Arr.113111”eleei=11211411111( 4#1641 _ 4.gxior-f0" -. .fe..l,* t 4,,: kt 1 1 AtkaA1T0.• A w`4 sr 1,11:110 ti• p:.yaa „itig ,.4Wsilkot1am&SNIike 4- 1. .isiglitivi-1;41410-101-1-. .-111NATS-Y, ; NIL, I NO etlibffilli4t.s i ?a 4 t :f- ' t. ._._. .44, IL : 01111Y -11 •-- 4i11.1 -mil. Oh ;t BM _ . Nts, V ``,` `145` / ._i { ILL t _ %. IN r( WWII 1 (..-k -- ;N* i 4........_.„,_-___, ,ligrianb:-.---- . tg• '...J. - ' s• i) 're•'>--- MA,,„...-, I. X ...map 11,14.1 Il r• primi. 14Q v-waleiI7- ,rfluipl 4 , _40 s,„ it,__I i /t. • , ACtiliglii lorking. i t4j J_` .-'•\. 4Lik rely L p _ vii.mipkaaii Maim lk it . .c / 14\ 111 ti aserilipik 11-'A ...„,d, - g . ,.. -......._,...7._ ,..... 10-r. , s.. VI if i "AI - ‘...,i4iv Ill i. . trh, lr ,i. .7- f., „..„ ._._._. ._. . az . c.• A, - _ i E.N ILIA ' 2-YEAR 24-HOUR PRECIPITATION ally 3.4•"""' ISOPLUVIALS OF 2-YEAR 24-HOUR rl'' • 3•= TOTAL PRECIPITATION IN INCHES • WIN 'r rilk Y• 0 1 2 3 4 5 6 7 8 Mlles I1; i ry __ 1: 300,000 3 5.1-8 KING COUNTY, W AS HINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1E 10-YEAR 24-HOUR ISOPLUVIALS 24 ippo ,t l I ; --= N -- _ •--- - •-- i----•-- - 7 - ----- - 23, kNaleittie-eltart" A 1 4 •... piimar -\-:,;-,a'.41 A oglik ,2.5 .; ipt-RIF1 41iriL .Mai or _ .nor '-ii pay lika 6-=2.6 I en - , 0 g 2.7 i 111111Si ii -. .4401,11 ..,,OfA 11% 2-8 .25.14-11k.4.-ji ..), - S -- am VolfriffIf" 1 iii vf 1 ek,AFirT4 z....- 7- 1- ,... _i. 9 .‘ Pithipataiga•- - AO& illill&V,..If --c;, 1' i2k r` ' tom.u°.s i A -. . 15-viL : •ri pfillr gill-:: : '‘, 111.4. 1, %. z--iikliV iviN Ai. I - ii, gh# P-91.-... . ..,,drars Alb, v Itgitiatlilk 1,Al., it,1 itif kr-3.42 0 II i 1 k r./ rrivit _ tkiv 441 iiiiikik 1 (. 01 Mil . 4 Atoll* ' =e> Ss- rdshiris,-.4• 1.1,,,..„.0A._,111.AllpIte 1 a3 i. _,- -\ 'tali 44,, est _ .0,4, -c v: 4 lif I Ilit IV"' 211"4111k ) TR: i ::-..,. ill I irlk \likliko_OA sig vIk k 114D giriok klatibal 41111111,1a krktsr ,./ „a ,, ii,.. tr...._ r , .0'7 IntoOIL '. Lils mililigi ,. . nx:in iv kIwo 4or j ri tairbnli.,,mmmingrfilifilL . drif .7, 1„._. c, ,Nt 1 w ro11IVei5I . I irr1rio •c 4--- top regiroir1104— C, - wfA .kla illmetImPimei_s7---\...,..-- wil, 11, fv 444. ihAd4 raldriSIR:-... 01,,,,7 iry i,,,\ 7 ..,imsr.s,iitisivitil I, I. ...:.__fa. ..xorhy 1 .. ImAttilltir 12 rwi1i '•i 4 .0-YEAR 24-HOUR PRECIPITATION ter ter>>' 3.4 r 1SOPLUVIALS OF 10-YEAR 24-HOUR ti' 4- ! ralr '- TOTAL PRECIPITATION IN INCHES n,0 1,11fa - alfrw WillOr °e- 'e o 1 2 3 4 5 6 7 8 Mlles 5 J A t. - i, 300nnn 3.5.1-10 3 G) 1/co - 4.0 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1H 100-YEAR 24-HOUR ISOPLUVIALS 0- N., ti -- T - - - - - -3./' willpreer id it . , 74 .1„„,, _i2 .-‘ spiwartr. i r•-....--7, (- -: \,.---\ 7.-: 2: -,..:1) .., Illi 3.skT.9 .• 34,4101.... _ \, ::-Alavi. ,. ... 1 • Oe 4.0 / 1.,,,direaltir ' r 1...-...,440 1.1M__il :.- ' 1 ._ ____ , sek___, 14,.._ rimeme „I ., dipp"14. \ • L-Pc_.._i 4, i 111110 Am 4 t sue.wR/1 odjok 4 t - II iwitiik... 40, -tieitaftwisk-NOII ...:k v4votrri" --"Rucuproute~jtiimmigalr& , 16 CIAPIII . teal%tliW...,g 00101 .s . 1-1 Ack\ 4' 1 4S + 11' Il1l tr tO., dfr11.V0ff.ii*". r cry. frtir.c.11\ "Am * ARIZ- • v itailfteiw. liPlw„t .e.r- \ surEL riiiiiiktIviedalpteikinki imitP1 f, , Nik 44it` 1SA - ' 4- I;, i `ig 4ivi `i k tik iliall - " 1 itit 1".. ilk- ilak 410.1. ,,,, SWAP mw'. i 4,''. Varierial ii. - N, r-) vejlip °" • plill 1 ,. .: . "goliq oil v4, ' IMil 11. . lifirra0VOLI Illbs11Off' ''-:"t... 1111-Rmi itedilligire. -- ‘, ..0 i- -- z:_-: i.------•._ si 4ii,ti4kfAitf1ro4A t!. a1Iknv1tiricy,o v .!1it RiwwV1nw,w!A atti,ANa- h, 1 7_ rawrib ,.!,...41.4111,MILW- gig k- ioptomfraftwriwgh. --4 1- ek AwltiV Medir ''' . -NAlarglil tyir.,,,,.. y 11 47 - .- k• - • - SAN, .,„ ;It 10 YEAR 24-HOUR PRECIPITATION 41TWAVAINA110 65. ISOPLUVIALS OF 100-YEAR 24HOUR it - . §4,t)` N -•Aw. TOTAL PRECIPITATION IN INCHES pcl' aillir 5•S tw 0 oilt 17 O 1 2 3 a 5 6 7 6 Mlles 4• 35.1-13 O 1: 300.000 0' 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 4BLE 3.5.2E SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type to rainfall distribution. 24-hour storm duration. CURVE NUMBERS BY• • HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION A • B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 \ 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land:undisturbed 42 64 76 81 Wood or forest land:young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces. lawns, parks. golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area Ci 80 t 90 fair condition: grass cover on 50% to 75%of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 98 Open water bodies: lakes,wetlands, ponds. etc. 1 s.' 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA a8 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments. impervious condominiums, apartments, must be computed commercial business and industrial areas. 1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology Chapter 9. August 1972. 2) Assumes roof and driveway runoff is directed into street/storm system. 3) The remaining pervious areas (lawn) are considered to be in good condition (or these curve numbers 3.5.2.3 1/90 POND 1 11/ 4/94 Barghausen Engineers page 1 SEGALE MOBILE HOME PARK INFILTRATION POND 1 BCE #5149 BASIN SUMMARY BASIN ID: lA NAME: 100YR POSTDEV. RUNOFF SBUH METHODOLOGY TOTAL AREA 51.25 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE TYPE1A PERVIOUS AREA PRECIPITATION 3 . 90 inches AREA. . : 29 .72 Acres TIME INTERVAL 10. 00 min CN 68 . 00 TIME OF CONC 7.23 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 21.53 Acres CN 98 . 00 TcReach - Sheet L: 100. 00 ns: 0. 0110 p2yr: 2. 00 s: 0. 0150 TcReach - Channel L: 1700. 00 kc:42. 00 s: 0. 0150 PEAK RATE: 22. 63 cfs VOL: 9.41 Ac-ft TIME: 480 min BASIN ID: 2A NAME: WET POND CALCULATION SBUH METHODOLOGY TOTAL AREA 51.25 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE TYPE1A PERVIOUS AREA PRECIPITATION 0. 67 inches AREA. . : 29 .72 Acres TIME INTERVAL 10. 00 min CN 68 . 00 TIME OF CONC 7 .23 min IMPERVIOUS AREA ABSTRACTION COEFF: 0.20 AREA. . : 21.53 Acres CN 98. 00 TcReach - Sheet L: 100. 00 ns: 0. 0110 p2yr: 2 . 00 s: 0. 0150 TcReach - Channel L: 1700. 00 kc:42. 00 s: 0. 0150 PEAK RATE: 2 . 33 cfs VOL: 0.85 Ac-ft TIME: 480 min 11/ 4/94 Barghausen Engineers page 2 SEGALE MOBILE HOME PARK INFILTRATION POND 1 BCE /5149 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf-AcFt Acres 1 22 . 631 480 409686 cf 51. 25 /O0 'lc f °Si- 2 2 . 329 480 36909 cf 51. 25 Lt ?pond calo.. l t'o1 3 2 . 307 1150 36232 cf 0. 00 OVezflo,, f',-a... Poici 2 4 22 . 631 480 459744 cf 51.25 60016;,tq+i0,1 H101 . / 2 3 5 2 . 660 270 457231 cf 51.25 too 7 ec+;,q I N N N N N N gbz ' 9LZ S Li 1 . 12°) o f AN= N- 88 / toe f o00 LfL' 2s pi 1s mmm7VfTTT H 1Y1N 090 7 6 0{rC IS o')o / 1) 6 oat:8 Z ZE 7o/13 p) 3wiQA c) -ti3171 13 I # cfNad rol LCV L9ct v L - 0.1. S Iva Li-v-i n01-`7 15 4' 3 asl7fl' L- NIZ S arvod roi rfl L2cr Irao In, -u ncar 11/ 4/94 Barghausen Engineers page 3 SEGALE MOBILE HOME PARK INFILTRATION POND 1 BCE #5149 STAGE STORAGE TABLE CUSTOM STORAGE ID No. 1 Description: RETENTION POND STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 32.00 0.0000 0.0000 34.80 89656 2.0582 37.60 252223 5.7902 40.40 420398 9.6510 32.20 6404 0.1470 35.00 96060 2.2052 37.80 264235 6.0660 40.60 432411 9.9268 32.40 12808 0.2940 35.20 108073 2.4810 38.00 276248 6.3418 40.80 444423 10.203 32.60 19212 0.4410 35.40 120085 2.7568 38.20 288261 6.6176 41.00 456436 10.478 32.80 25616 0.5881 35.60 132098 3.0325 38.40 300273 6.8933 41.20 468449 10.754 33.00 32020 0.7351 35.80 144110 3.3083 38.60 312286 7.1691 41.40 480461 11.030 33.20 38424 0.8821 36.00 156123 3.5841 38.80 324298 7.4449 41.60 492474 11.306 33.40 44828 1.0291 36.20 168135 3.8599 39.00 336311 7.7206 41.80 504486 11.581 33.60 51232 1.1761 36.40 180148 4.1356 39.20 348323 7.9964 42.00 516499 11.857 33.80 57636 1.3231 36.60 192160 4.4114 39.40 360336 8.2722 42.20 528511 12.133 34.00 64040 1.4702 36.80 204173 4.6872 39.60 372348 8.5479 42.40 540524 12.409 34.20 70444 1.6172 37.00 216185 4.9629 39.80 384361 8.8237 42.60 552536 12.684 34.40 76848 1.7642 37.20 228198 5.2387 40.00 396373 9.0995 42.80 564549 12.960 34.60 83252 1.9112 37.40 240210 5.5145 40.20 408386 9.3752 43.00 576561 13.236 11/ 4/94 Barghausen Engineers page 4 SEGALE MOBILE HOME PARK INFILTRATION POND 1 BCE #5149 STAGE DISCHARGE TABLE DISCHARGE LIST ID No. 1 Description: INFILTRATION POND STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 32.00 2.6600 34.80 2.6600 37.60 2.6600 40.40 2.6600 32.10 2.6600 34.90 2.6600 37.70 2.6600 40.50 2.6600 32.20 2.6600 35.00 2.6600 37.80 2.6600 40.60 2.6600 32.30 2.6600 35.10 2.6600 37.90 2.6600 40.70 2.6600 32.40 2.6600 35.20 2.6600 38.00 2.6600 40.80 2.6600 32.50 2.6600 35.30 2.6600 38.10 2.6600 40.90 2.6600 32.60 2.6600 35.40 2.6600 38.20 2.6600 41.00 2.6600 32.70 2.6600 35.50 2.6600 38.30 2.6600 41.10 2.6600 32.80 2.6600 35.60 2.6600 38.40 2.6600 41.20 2.6600 32.90 2.6600 35.70 2.6600 38.50 2.6600 41.30 2.6600 33.00 2.6600 35.80 2.6600 38.60 2.6600 41.40 2.6600 33.10 2.6600 35.90 2.6600 38.70 2.6600 41.50 2.6600 33.20 2.6600 36.00 2.6600 38.80 2.6600 41.60 2.6600 33.30 2.6600 36.10 2.6600 38.90 2.6600 41.70 2.6600 33.40 2.6600 36.20 2.6600 39.00 2.6600 41.80 2.6600 33.50 2.6600 36.30 2.6600 39.10 2.6600 41.90 2.6600 33.60 2.6600 36.40 2.6600 39.20 2.6600 42.00 2.6600 33.70 2.6600 36.50 2.6600 39.30 2.6600 42.10 2.6600 33.80 2.6600 36.60 2.6600 39.40 2.6600 42.20 2.6600 33.90 2.6600 36.70 2.6600 39.50 2.6600 42.30 2.6600 34.00 2.6600 36.80 2.6600 39.60 2.6600 42.40 2.6600 34.10 2.6600 36.90 2.6600 39.70 2.6600 42.50 2.6600 34.20 2.6600 37.00 2.6600 39.80 2.6600 42.60 2.6600 34.30 2.6600 37.10 2.6600 39.90 2.6600 42.70 2.6600 34.40 2.6600 37.20 2.6600 40.00 2.6600 42.80 2.6600 34.50 2.6600 37.30 2.6600 40.10 2.6600 42.90 2.6600 34.60 2.6600 37.40 2.6600 40.20 2.6600 43.00 2.6600 34.70 2.6600 37.50 2.6600 40.30 2.6600 43.00 2.6600 11/ 4/94 Barghausen Engineers page 5 SEGALE MOBILE HOME PARK INFILTRATION POND 1 BCE #5149 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE DESCRIPTION cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 100YR ROUTING 3.34 22.63 1 1 37.46 5 243667 i NNNNNN 10 a. AAAAl)-. I N r V' Q l SSS ` NN 000 G170 ‘Ern Q2 I o /ZNNN J7) 3wfr-1c) i'3V13 I,tCJ6 "" 1 /' 1'4C") -ID15.° 1:› Pi2." 1/4A" G.'A Qr`'Qd L - ofsNoi.Lvii9 -71:+2Ibees3-e . 9N17IC` iiNo-4IMarm./ -)rlo6-Dr POND 2 11/ 4/94 Barghausen Engineers page 1 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf-AcFt Acres 1 3 . 500 800 110193 cf 0. 00 Over ric. , frD"% PonCl SA 2 2 . 607 1150 90052 cf 0. 00 lao yr /2ak+'^ 3 0. 300 20 53820 cf 0. 00 f'onc) L., , /tr°C1'o^ 4 2 . 307 1150 36232 cf 0. 00 / ;SU Overnot.) +o Pond I D.C.) V IGN11 )/v rONL! .>ILINU I. NGI- Oti, BCE f 5141 cm-cuL..4T Ion/S to -lo -14 P a ,1 D I* 2 E 5r) voi_u,4 e (cf) 3 $ 3, t10A 41 2.7 8 N N VI W 4 2 18 2_W W W i N N Yf O O O f1OO C Tr ir et CI C C1 C C CI 11/ 4/94 Barghausen Engineers page 2 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 STAGE STORAGE TABLE CUSTOM STORAGE ID No. 1 Description: RETENTION POND STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 38.00 0.0000 0.0000 39.60 13141 0.3017 41.20 26282 0.6033 42.80 39422 0.9050 38.20 1643 0.0377 39.80 14783 0.3394 41.40 27924 0.6411 43.00 41065 0.9427 38.40 3285 0.0754 40.00 16426 0.3771 41.60 29567 0.6788 43.20 42708 0.9804 38.60 4928 0.1131 40.20 18069 0.4148 41.80 31209 0.7165 43.40 44350 1.0181 38.80 6570 0.1508 40.40 19711 0.4525 42.00 32852 0.7542 43.60 45993 1.0558 39.00 8213 0.1885 40.60 21354 0.4902 42.20 34495 0.7919 43.80 47635 1.0936 39.20 9856 0.2263 40.80 22996 0.5279 42.40 36137 0.8296 44.00 49278 1.1313 39.40 11498 0.2640 41.00 24639 0.5656 42.60 37780 0.8673 11/ 4/94 Barghausen Engineers page 3 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 STAGE DISCHARGE TABLE DISCHARGE LIST ID No. 1 Description: INFILTRATION POND 2 STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs I 38.00 0.3000 39.80 0.3000 41.60 0.3000 43.40 0.3000 38.10 0.3000 39.90 0.3000 41.70 0.3000 43.50 0.3000 38.20 0.3000 40.00 0.3000 41.80 0.3000 43.60 0.3000 38.30 0.3000 40.10 0.3000 41.90 0.3000 43.70 0.3000 38.40 0.3000 40.20 0.3000 42.00 0.3000 43.80 0.3000 38.50 0.3000 40.30 0.3000 42.10 0.3000 43.90 0.3000 38.60 0.3000 40.40 0.3000 42.20 0.3000 44.00 0.3000 38.70 0.3000 40.50 0.3000 42.30 0.3000 44.10 0.3000 38.80 0.3000 40.60 0.3000 42.40 0.3000 44.20 0.3000 38.90 0.3000 40.70 0.3000 42.50 0.3000 44.30 0.3000 39.00 0.3000 40.80 0.3000 42.60 0.3000 44.40 0.3000 39.10 0.3000 40.90 0.3000 42.70 0.3000 44.50 0.3000 I 39.20 0.3000 41.00 0.3000 42.80 0.3000 44.60 0.3000 39.30 0.3000 41.10 0.3000 42.90 0.3000 44.70 0.3000 39.40 0.3000 41.20 0.3000 43.00 0.3000 44.80 0.3000 39.50 0.3000 41.30 0.3000 43.10 0.3000 44.90 0.3000 39.60 0.3000 41.40 0.3000 43.20 0.3000 45.00 0.3000 j 39.70 0.3000 41.50 0.3000 43.30 0.3000 45.00 0.3000 11/ 4/94 Barghausen Engineers page 4 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 STAGE DISCHARGE TABLE RISER DISCHARGE ID No. 2 Description: RISER STRUCTURE Riser Diameter (in) : 18. 00 elev: 43 . 65 ft Weir Coefficient. . . : 3 .782 height:45. 00 ft Orif Coefficient. . . : 9.739 increm: 0. 10 ft STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 43.65 0.0000 44.00 3.0249 44.40 7.3694 44.80 9.1254 43.70 0.1633 44.10 4.4099 44.50 7.8454 44.90 9.5139 43.80 0.8487 44.20 5.9587 44.60 8.2940 45.00 9.8871 43.90 1.8261 44.30 6.8606 44.70 8.7196 45.00 9.8871 11/ 4/94 Barghausen Engineers page 5 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. 3 Description: COMBINATION 1 AND 2 Structure: 1 Structure: Structure: 2 Structure: Structure: STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 38.00 0.3000 39.30 0.3000 40.60 0.3000 41.90 0.3000 38.10 0.3000 39.40 0.3000 40.70 0.3000 42.00 0.3000 38.20 0.3000 39.50 0.3000 40.80 0.3000 42.10 0.3000 38.30 0.3000 39.60 0.3000 40.90 0.3000 42.20 0.3000 38.40 0.3000 39.70 0.3000 41.00 0.3000 42.30 0.3000 38.50 0.3000 39.80 0.3000 41.10 0.3000 42.40 0.3000 38.60 0.3000 39.90 0.3000 41.20 0.3000 42.50 0.3000 38.70 0.3000 40.00 0.3000 41.30 0.3000 42.60 0.3000 38.80 0.3000 40.10 0.3000 41.40 0.3000 42.70 0.3000 38.90 0.3000 40.20 0.3000 41.50 • 0.3000 42.80 0.3000 39.00 0.3000 40.30 0.3000 41.60 0.3000 42.90 0.3000 39.10 0.3000 40.40 0.3000 41.70 0.3000 43.00 0.3000 39.20 0.3000 40.50 0.3000 41.80 0.3000 45.00 0.3000 11/ 4/94 Barghausen Engineers page 6 SEGALE MOBILE HOME PARK INFILTRATION POND 2 BCE JOB #5149 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE DESCRIPTION cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 100YR ROUTING 0.30 3.50 1 3 43.94 2 48786.23 POND 3A+3B 10/10/94 Barghausen Engineers page 1 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 BASIN SUMMARY BASIN ID: lA NAME: 100YR POSTDEV. RUNOFF (SOUTH) SBUH METHODOLOGY TOTAL AREA 45. 00 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE TYPE1A PERVIOUS AREA PRECIPITATION 3 . 90 inches AREA. . : 22 .78 Acres TIME INTERVAL 10. 00 min CN 68 . 00 TIME OF CONC 7 . 63 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 22 . 22 Acres CN 98 . 00 TcReach - Sheet L: 100. 00 ns: 0. 0110 p2yr: 2 . 00 s: 0. 0100 TcReach - Channel L: 2000 . 00 kc: 42 . 00 s: 0. 0200 PEAK RATE: 21. 87 cfs VOL: 8 . 96 Ac-ft TIME: 480 min BASIN ID: 2A NAME: WET POND CALCULATION SBUH METHODOLOGY TOTAL AREA 45. 00 Acres BASEFLOWS: 0. 00 cfs RAINFALL TYPE TYPE1A PERVIOUS AREA PRECIPITATION 0. 67 inches AREA. . : 22 . 78 Acres TIME INTERVAL 10. 00 min CN 68 . 00 TIME OF CONC 7 . 63 min IMPERVIOUS AREA ABSTRACTION COEFF: 0. 20 AREA. . : 22 . 22 Acres CN 98 . 00 TcReach - Sheet L: 100. 00 ns: 0. 0110 p2yr: 2 . 00 s: 0. 0100 TcReach - Channel L: 2000. 00 kc:42 . 00 s: 0. 0200 PEAK RATE: 2 . 41 cfs VOL: 0. 88 Ac-ft TIME: 480 min 10/10/94 Barghausen Engineers page 2 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf-AcFt Acres 1 21. 871 480 390092 cf 45. 00 /00 yr Pos-t- 2 2 . 408 480 38320 cf 45 . 00 WL'- Pad c4)ck14+10^ 3 4 . 749 800 323679 cf 45 . 00 too yr Wow-H.-9 4 1. 190 20 213486 cf 0. 00 Tnc; )fra+i0-^ 5 3 . 500 800 110193 cf 0. 00 e';s, Overflow to PO Ad 22" Jc.1al( moo.lc no-4- rc", .1)E T/on) POND SIZING T. /JG/Sch 3c 5111 CALCVLATIoAiS o - /o -94 De"FENTIo4 P ND It 3A -- 3B EL AEA (Sf) VOLUME (LE) 40 z, 826 4S ` / S 43 17,786 45, 9/8 W d. we.1) W W 4 3 (' ,00,4 3/2q1 000 138, 282 or S4/ ,47 8// Zoa N a! aaa N C CINN aF a i 1 10/10/94 Barghausen Engineers page 3 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 STAGE STORAGE TABLE CUSTOM STORAGE ID No. 1 Description: INFILTRATION POND 3A + 3B STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 40.00 0.0000 0.0000 41.80 27551 0.6325 43.60 66660 1.5303 45.40 128887 2.9588 40.20 3061 0.0703 42.00 30612 0.7028 43.80 73574 1.6890 45.60 135801 3.1176 40.40 6122 0.1406 42.20 33673 0.7730 44.00 80489 1.8478 45.80 142715 3.2763 40.60 9184 0.2108 42.40 36734 0.8433 44.20 87403 2.0065 46.00 149630 3.4350 40.80 12245 0.2811 42.60 39796 0.9136 44.40 94317 2.1652 46.20 156544 3.5937 41.00 15306 0.3514 42.80 42857 0.9839 44.60 101231 2.3239 46.40 163458 3.7525 41.20 18367 0.4217 43.00 45918 1.0541 44.80 108145 2.4827 46.60 170372 3.9112 41.40 21428 0.4919 43.20 52832 1.2129 45.00 115059 2.6414 46.80 177286 4.0699 41.60 24490 0.5622 43.40 59746 1.3716 45.20 121973 2.8001 47.00 184200 4.2287 10/10/94 Barghausen Engineers page 4 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 STAGE DISCHARGE TABLE DISCHARGE LIST ID No. 1 Description: INFILTRATION POND 3a + 3b STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 40.00 1.1900 42.10 1.1900 44.20 1.1900 46.30 1.1900 40.10 1.1900 42.20 1.1900 44.30 1.1900 46.40 1.1900 40.20 1.1900 42.30 1.1900 44.40 1.1900 46.50 1.1900 40.30 1.1900 42.40 1.1900 44.50 1.1900 46.60 1.1900 40.40 1.1900 42.50 1.1900 44.60 1.1900 46.70 1.1900 40.50 1.1900 42.60 1.1900 44.70 1.1900 46.80 1.1900. 40.60 1.1900 42.70 1.1900 44.80 1.1900 46.90 1.1900 40.70 1.1900 42.80 1.1900 44.90 1.1900 47.00 1.1900 40.80 1.1900 42.90 1.1900 45.00 1.1900 47.10 1.1900 40.90 1.1900 43.00 1.1900 45.10 1.1900 47.20 1.1900 4'.00 1.1900 43.10 1.1900 45.20 1.1900 47.30 1.1900 41.10 1.1900 43.20 1.1900 45.30 1.1900 47.40 1.1900 41.20 1.1900 43.30 1.1900 45.40 1.1900 47.50 1.1900 4".30 1.1900 43.40 1.1900 45.50 1.1900 47.60 1.1900 4'.40 1.1900 43.50 1.1900 45.60 1.1900 47.70 1.1900 41.50 1.1900 43.60 1.1900 45.70 1.1900 47.80 1.1900 41.60 1.1900 43.70 1.1900 45.80 1.1900 47.90 1.1900 41.70 1.1900 43.80 1.1900 45.90 1.1900 48.00 1.1900 41.80 1.1900 43.90 1.1900 46.00 1.1900 48.00 1.1900 41.90 1.1900 44.00 1.1900 46.10 1.1900 42.00 1.1900 44.10 1.1900 46.20 1.1900 10/10/94 Barghausen Engineers page 5 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 STAGE DISCHARGE TABLE RISER DISCHARGE ID No. 2 Description: RISER OVERFLOW Riser Diameter (in) : 24 . 00 elev: 46. 65 ft Weir Coefficient. . . : 3 . 782 height: 48 . 00 ft Orif Coefficient. . . : 9 . 739 increm: 0. 10 ft STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 46.65 0.0000 47.00 4.0332 47.40 12.651 47.80 16.223 46.70 0.2178 47.10 5.8798 47.50 13.947 47.90 16.914 46.80 1.1316 47.20 7.9449 47.60 14.745 48.00 17.577 46.90 2.4347 47.30 10.207 47.70 15.502 48.00 17.577 10/10/94 Barghausen Engineers page 6 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 STAGE DISCHARGE TABLE COMBINATION DISCHARGE ID No. 3 Description: COMBINATION 1 AND 2 Structure: 1 Structure: Structure: 2 Structure: Structure: STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> ft) ---cfs ft) ---cfs ft) ---cfs ft) ---cfs 40.00 1.1900 42.10 1.1900 44.20 1.1900 46.30 1.1900 40.10 1.1900 42.20 1.1900 44.30 1.1900 46.40 1.1900 40.20 1.1900 42.30 1.1900 44.40 1.1900 46.50 1.1900 40.30 1.1900 42.40 1.1900 44.50 1.1900 46.60 1.1900 40.40 1.1900 42.50 1.1900 44.60 1.1900 46.70 1.4078 40.50 1.1900 42.60 1.1900 44.70 1.1900 46.80 2.3216 40.60 1.1900 42.70 1.1900 44.80 1.1900 46.90 3.6247 40.70 1.1900 42.80 1.1900 44.90 1.1900 47.00 5.2232 40.80 1.1900 42.90 1.1900 45.00 1.1900 47.10 7.0698 40.90 1.1900 43.00 1.1900 45.10 1.1900 47.20 9.1349 41.00 1.1900 43.10 1.1900 45.20 1.1900 47.30 11.397 41.10 1.1900 43.20 1.1900 45.30 1.1900 47.40 13.841 41.20 1.1900 43.30 1.1900 45.40 1.1900 47.50 15.137 41.30 1.1900 43.40 1.1900 45.50 1.1900 47.60 15.935 41.40 1.1900 43.50 1.1900 45.60 1.1900 47.70 16.692 41.50 1.1900 43.60 1.1900 45.70 1.1900 47.80 17.413 41.60 1.1900 43.70 1.1900 45.80 1.1900 47.90 18.104 41.70 1.1900 43.80 1.1900 45.90 1.1900 48.00 18.767 41.80 1.1900 43.90 1.1900 46.00 1.1900 41.90 1.1900 44.00 1.1900 46.10 1.1900 42.00 1.1900 44.10 1.1900 46.20 1.1900 10/10/94 Barghausen Engineers page 7 SEGALE MOBILE HOME PARK INFILTRATION POND 3A AND 3B (SOUTH BASIN) BCE JOB #5149 LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE DESCRIPTION cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 100 YR ROUTING 1.19 21.87 1 3 46.97 3 183174 CE 5111 CAL CVLAT'raAJS 10 - 1 - `j4 Po lJ D gA 4 3 /3 1 VoIk4 ra.td. = 39, 220 cf(Sty. klyd, ZJ Vo/ \? t pr.av;d : F_ L 42Ei1 (5-r) Vow.v+E ( ) W W W 0 z, 2 4)5 14, 215NNN ICI 43 17, 285 era Cr et ev er ri err(er a PF e) 1t -4- kit- I t 1old e_rfc' 7• NGI5. . 3cE .t7S5/9-q cat- c lit_<1 rlo JS I Ifl-1 - 9 4 Po 1J P 4P 3A- 4 3 ' V A 1,4 ratio). = 38, 3 2 o c f (5 4yd. # Z) Vole E L A EA (5 c) v'o wfri E (e. ) InVIC 40 2/ 2' 5WWW 9NNN 1 14 r 2 / 5 43 17, 285 Nav NN N NN 1 II. 1i .1 r , r I .•1 1,.I '1,r1 .. i 1 c .I un11I 1„1.1„ fit M.. .L. trti-moi 1. . :.1 "", '' ,‘, .., •... • 0, 4--,-„„, /1, / a . ...) ° ,,, I> S_ 214D cr 3R y 1 ,. 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CITY OF RENTON REPORT AND DECISION f APPLICANT: DANA WARREN, M. A. SEGALE, INC. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023, CU/V/MHP/ECF LOCATION: SE of the intersection of NE 3rd Street and Edmonds Avenue NE SUMMARY OF REQUEST: Applicant proposes development of a 402-unit manufactured home community. The development is on a site that was a E former gravel mining operation. Development would occur in E. I V L J four phases, commencing in 1995. A Conditional Use Permit is requested to allow a parking area for up to 100 unoccupied 7 recreational vehicles. A variance is requested to allow three- foot side yard setback on each residential lot in the area of the attached site-built garage. To provide access, Edmonds Avenue NE will also be extended 500 feet to the south as a public street. SUMMARY OF ACTION: Development Services Recommendation: Approve with conditions. DEVELOPMENT SERVICES REPORT: The Development Services Report was received by the Examiner on April 19, 1995. PUBLIC HEARING: After reviewing the Development Services Report, examining available information on file with the application, field checking the property and surrounding area; the Examiner conducted a public hearing on the subject as follows: MINUTES The following minutes are a summary of the April 25, 1995 hearing. The legal record is recorded on tape. The hearing opened on Tuesday, April 25, 1995, at 9:02 a.m. in the Council Chambers on the second floor of the Renton Municipal Building. JAMES L. COLT, 102 Monterey Place NE, Renton, WA 98056, appearing for American Memorial Services at P.O. Box 1745, Bellevue, WA 98009, claimed that American Memorial did not receive the statutory or regulatory notice to property owners for the public hearing. He requested a continuance. After researching the issue raised by Mr. Colt, the Examiner determined that American Memorial Services received the appropriate and legal notification of the hearing and that City Code does not provide for any additional or special notification. DANA WARREN,M.A.SEGALE,IN,.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CUN/MHP/ECF May 23, 1995 Page 2 The parties wishing to testify were then affirmed by the Examiner and the following exhibits were entered into the record: Exhibit No. 1: Yellow file containing the original Exhibit No. 2: Site vicinity map. application, proof of posting, proof of publication and other documentation pertinent to this request. Exhibit No. 3: Neighborhood detail map. Exhibit No. 4: Site development concept. Exhibit No. 5: Site development drawing showing Exhibit No. 6: Generalized landscape plan of the construction phasing plan. overall site. Exhibit No. 7: Architect's rendering of a typical Exhibit No. 8: Architect's rendering of the streetscape. community center, its landscaping and the entrance to the development. Exhibit No. 9: Landscape plan showing typical Exhibit No. 10: Typical floor plan of a residential landscaping around residential units. unit. Exhibit No. 11: Drawing representing various yard Exhibit No. 12: Alternate site plan. setbacks. Exhibit No. 13: April 24, 1995 letter from Exhibit No. 14: November 19, 1982 letter from City AnMarCo to Dana Warren of M.A. Segale, Inc. of Renton Public Works to James Colt of Mt. Olivet Cemetery. Exhibit No. 15: Aerial photograph of site submitted Exhibit No. 16: Aerial photograph of site submitted by James Colt, dated 3/14/88. by James Colt, dated 2/13/90. Exhibit No. 17: Aerial photograph of site submitted Exhibit No. 18: May 20, 1982 letter from the by James Colt, dated 3/21/87. Department of Ecology to Ron Nelson of the City of Renton in regarding to a complaint filed by James Colt. The hearing opened with a presentation of the staff report by JENNIFER TOTH HENNING, Project Manager, Development Services, City of Renton, 200 Mill Avenue South, Renton, Washington 98055. The owner of the subject property is M.A. Segale, Inc. The zoning designation is Residential Manufactured Homes(RM-H)and Resource Conservation(RC). The Comprehensive Plan Land Use Designation is Residential Single Family and Residential Rural. The existing site use is an abandoned gravel mine,vacant and open space. To the north are multi-family residential uses, to the east is the King County Transfer Station, King County Shops and vacant land. To the south are vacant open space and single family residential uses. To the west are the Mt. Olivet Cemetery and vacant land. Access would be from NE 3rd Street and Edmonds Avenue NE. The site area is 133.29 acres. Public services consist of water from an existing 16-inch main in NE 3rd Street. Sewer is provided from a 24-inch interceptor that runs through the site. Surface water and stormwater service is DANA WARREN,M.A.SEGALE,IN.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CUN/MHP/ECF May 23, 1995 Page 4 Approximately 7.1 acres of the net site will be for recreation and open space. One of these acres is dedicated to a community center. The remaining recreation and open space area would be reserved as passive open space. There will also be a seating/viewing area developed along the southern point at the top of the bluff. A walking trail will be developed from the community center to the seating/viewing area. Lighting is proposed for each home that will illuminate the street. It will be controlled by sensors so that all lights are activated at dusk and turned off at sunrise each day. Lighting will be installed, maintained and replaced by site managers. Residents will not be able to remove the lighting. The applicant has provided a generalized landscape plan for the overall site. The sketches show a landscape treatment in the front yard area of each home site. The ERC has required additional landscape treatment on the site beyond that proposed by the applicant. This proposal also includes private patio areas and private yards for each unit. The Conditional Use Permit(CUP)for a 100 space parking/storage area for recreational vehicles is requested. The proposal complies with the standards of the RM-H zone. The standard is screened parking at a ratio of one parking space for every ten lots. Under this proposal, one parking space for every four lots will be provided. Setbacks will be twenty feet from the power line easement. There will be a six foot high fence and security lighting that will not exceed the 30 foot height limit. A variance is requested from the five foot side yard setback for the manufactured homes and any attached accessory units. The applicant requests a variance to allow a three foot minimum side yard setback on one side of each lot, along the site-built attached garages so long as the length of the garapze as measured along the side yard property line does not exceed twenty-five feet in length. This variance request is consistent with variance criteria in that the subject property is constrained by topography, irregular shape, in the presence of major electrical transmissions lines easements, and is located within the Aquifer Protection Area(Zones 1 and 2). Of the 133.29 gross acres on this site, there are 71.17 net acres. The net acreage includes steep slopes that preclude development on approximately 10 acres. This leaves approximately 45 percent of the site for development. The usable area is irregularly shaped due to topography and the presence of power line easements. In addition, the location of the site within Zones 1 and 2 of the APA restrict the way in which stormwater facilities are sited. The result of these constraints is that the lot layout is somewhat inefficient and the number of dwelling units per acre is reduced over what could be permitted. By allowing a variance for the reduced side yards on one side of each unit the project would fall within the permitted density range. In addition,the variance will provide each unit with added privacy and space for individual landscape treatment. This makes a more desirable living space. In closing, Ms. Henning stated that staff recommends approval of the Cedar Crest Manufactured Home Park application with the condition that the applicant meet the Mitigation Measures imposed by the Environmental Review Committee. LAURIE PINARD, corporate counsel for M. A. Segale, Inc., PO Box 88050,Tukwila, WA 98138, noted that they will comply with the mitigation measures imposed by the ERC and City staff. Approval of the CUP will allow development of a parking area for recreational vehicles. She noted that market research shows that recreational vehicle parking is a desirable feature to senior citizens since they use their RVs often. The variance will allow for a more desirable outside living space that includes a private yard and patio. Ms. Pinard pointed out that residential lots will average 4,500 square feet, but some lots will be approximately 4,000 square feet. This is well above the 3,000 square feet minimum. The private yard of each home will be maintained by the resident and all other areas will be maintained by on-site staff. Blaine Avenue NE will only be a secondary emergency access with a crash gate to limit access to the Fire Department and Police. The Codes, Covenants and Restrictions (CC&R's)will be completed before construction of the project. DANA WARREN,M.A.SEGALE,In,. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 3 provided by existing 12-inch and 16-inch storm lines in NE 3rd Street. Fire has sufficient resources to provide service. There are schools and parks in the area. The site is located within Zones 1 and 2 of the Aquifer Protection Area(APA). The project is to be constructed in four phases. The first phase consists of substantial site grading, installation of utilities, and development of Phase 1 homesites. Subsequent phases would occur in intervals of one to two years after the first phase is completed. Completion of the development may take up to ten years. The applicant is seeking approval to develop a 402-unit manufactured home park that will serve senior citizens. At least one resident of each home must be 55 years of age or older. No children may live in the development. Residents will purchase their home and lease the land. Under this proposal the portion of the site zoned Residential Manufactured Homes will be developed. The project will consist of manufactured homes with site- built two-car garages, a 4,500 square foot community center building, a 3,000 square foot landscape maintenance shelter, a 100-space recreational vehicle (RV)storage lot, recreational features, site utilities, and streets. Edmonds Avenue NE will be extended as a public street to provide access into the development. The development will feature a security gate at the entrance. All streets in the development will be private, 30-feet wide with 5-foot sidewalks on one side. The typical homesite averages 4,567 square feet. There will be no - subdivision of the land for individual lots. The homes will be manufactured off-site and delivered in sections for assembly on each site. Two or three bedroom homes will be available, with attached site-built two-car garage. Approximately 750,000 cubic yards of soil will be graded to create level home sites. Seventy-five thousand 75,000)cubic yards of fill material will be imported and 675,000 cubic yards will be moved on the site. Geotechnical negineershaverecommendeda25-foot setback from the eastern half of the bank and a 40 foot setbacTc from the westeiiI alf-Since the site-1i within Zones and-2 of the-T;ity's Aquifer Protection Area APA), stormwater must be collected and discharged in accordance with the Aquifer Protection Ordinance. Stormwater will be collected and piped to one of three retention/infiltration ponds located in Zone 2 of the APA. One hundred percent of the stormwater collected on site would be discharged through infiltration. The Environmental Review Committee(ERC) issued a Determination of Non-Significance- Mitigated DNS-M)for this proposal on March 27, 1995. Comments regarding water quality were received from METRO and comments regarding traffic were received from the Washington State Department of Transportation. The ERC required eight mitigation measures regarding site surface and slopes, cleanliness of imported fill materials, Traffic Mitigation Fee, street dedication,truck trips, parking regulations in the Codes, Covenants and Restrictions, slope stability impacts from release of water from infiltration ponds, and landscape treatment to avoid erosion and improve the aesthetic quality of the site. This proposal is consistent with the City's Mobile Home Park Plan criteria in regard to design and location and construction standards. The development will be built on approximately 61 acres, with access from NE 3rd Street via the Edmonds Avenue extension. Secondary emergency access will also be available from Blaine Avenue NE. Screening is proposed along the public streets. Extensive native vegetation and topography will limit views, providing a barrier along most of the boundaries. Typical lot depth is 85 feet, with a length of 55 feet. The total site is constrained by topography but care has been taken to optimize amenities such as view. Residential sites will include private garden areas. Density is approximately 5.65 dwelling units per acre. Setbacks as defined by the Residential Manufactured Home Zone are met with the exception of the required variance on the lot area that abuts the garage area. The two car garage on each site will have an apron in front that can provide additional parking space. Screened parking for RVs will be provided in an area along the western side of the project site. Parking for RVs is proposed at a ratio of one RV per four residential lots. DANA WARREN,M.A.SEGALE,In.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 5 DANA WARREN, M.A. Segale, Inc., PO Box 88050, Tukwila, WA 98138, explained that after the site is graded water will be used to keep the top soil from being blown away. It will be applied with a truck or sprinklers. He noted that some vegetation will grow naturally when the soil is irrigated and they intend to have the graded areas as aesthetically pleasing as possible. NEIL WATTS, Plan Review Supervisor for the City of Renton, 200 Mill Avenue South, Renton, WA 98055, noted that one of the mitigation measures imposed by the ERC requires that additional landscaping be provided during all phases of the project as a means of avoiding erosion and improving the aesthetic quality of the site. DAVID HALINEN, 10500 NE 8th Street, Suite 1900, Bellevue, WA 98004, attorney for the general partnership of AnMarCo., explained that AnMarCo is the owner of the property to the west of the southerly portion of the subject site. The AnMarCo property also lays south of Mt. Olivet cemetery. He explained that AnMarCo has committed to providing secondary emergency access to the subject site from Blaine Avenue NE. He submitted a letter from AnMarCo documenting its commitment. Mr. Watts addressed street issues, explaining that access will be on Edmonds Avenue from the existing intersection at NE 3rd. They will dedicate a full right-of-way for a fully improved street. The applicant and City have agreed that pavement width, from NE 3rd to the approximate location of the community center will be 36 feet wide. The City's Transportation Division requested that the paved roadway continue further south at a width of 36 feet. However,the applicant has requested reduction of the pavement width to approximately 28 to 32 feet. The request is under consideration, as there is some justification, specifically topography and a lesser need for parking along that section of street. However, full right-of-way will be required along this area. The applicant has agreed to provide pedestrian facilities along the east side of the new right-of-way and eventually, as the property owned by AnMarCo is developed, the road will be extended into that plat. There will be two points of access from NE Edmonds into the project. Additionally, there will be second emergency access from the southerly end of NE Edmonds Avenue extended to Blaine Avenue NE. Sidewalks will be installed along NE 3rd. Sometime near the fourth phase of the project, improvements will be made to the intersection of Edmonds and NE 3rd. Sewer improvements are already being constructed. Water system improvements will also be required and each of the homes will be separately water-metered. In regard to recreational vehicle parking, Mr. Watts stated that staff had considered alternate locations for the RV parking site. However, there are fairly steep slopes and some roadways are at a 15%grade. Other possible RV parking areas would have been remote from Edmonds. He pointed out that the chosen site lies underneath power lines and is the best use of space. In addition,the Fire Department had concerns about trying to access a more remote parking site. In regard to site grading,considerable grading will be needed. The major work will consist of moving dirt around the site. The ERC imposed several conditions to deal with grading. Professional engineers will monitor grading for compliance with ERC conditions, to document volume, perform compaction tests,to test for conformance to the grading and mining ordinance provisions, and to discover site suitability for development. Drainage will be provided through infiltration so there will be no discharge to the existing storm drainage system in NE 3rd Street. Mr. Watts explained that the site is split between Aquifer Protection Zone I and 2 and each zone has different restrictions on how drainage is handled. Zone 1 restrictions do not allow infiltration and do not allow wetponds or water quality swales. The applicant proposed a system that collects all the water from Zone 1 and directs the water north to APA Zone 2, which is well away from the steeper slopes above Maple DANA WARREN,M.A.SEGALE,IN.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 6 Valley Highway. The water then goes through a series of lined wetponds which prevent any untreated water from dispersing into the Aquifer. The water will then go through infiltration systems. Now appearing for Mt. Olivet Cemetery, JAMES L. COLT, 102 Monterey Place NE, Renton, WA 98056, asked a series of questions. Responding to Mr. Colt, Mr. Watts explained that streets and grading will be completed during the first phase. Mr. Warren explained that the development's entrance will be gated. They have not yet determined the time of day that gates would open and close. The intention is a point of security, possibly more perceived than actual, that restricts access particularly after daylight hours. Mr. Colt noted that Blaine Avenue NE is a dead end street and a significant amount of crime takes place at this location. He stated that the proposed new street will increase the opportunity for additional crime. In regard to grading, Mr. Colt asked what access road would be used for equipment. Mr. Watts explained that most equipment will stay on site. Mr. Warren stated that equipment would enter through the existing roadway and the extended Edmonds. Their second means of egress is to connect into the AnMarCo property and then to Blaine Avenue NE. They will not use the lower portion of Edmonds for access during the project and he believes that keeping the road private and adding a gate will limit access. Mr. Watts agreed, stating that the City should barricade the streets to limit access during development. In regard to discussion of the dedication of Edmonds, the Examiner stated that the City is requiring dedication of the entire length of Edmonds because it is on this site and is subject to this permit. Whether the road is developed or deferred is an issue that is not part of this hearing. The Examiner may require improvements as required by code and an applicant may receive a deferral of the improvements. Or,the Council can waive opening the road for a certain period of time. The road will be dedicated to the full length, including down to the RV parking lot. Construction standards will be determined. Normal requirements for a street are curbs, gutters, sidewalks, and street lighting. Mr. Colt questioned the street alignment that was chosen, stating that a different alignment would benefit the thousands of property owners at Mt. Olivet Cemetery. Mr. Watts explained that the topography of the chosen location will provide access to the future development. The City does not believe that the cemetery will be developed for anything other than what it is; however there is nothing in the chosen location that forecloses access to Mt. Olivet. The proposed road does not landlock Mt. Olivet's property. Mr. Colt stated that Mt. Olivet Cemetery had dedicated the roadway because it had no access to Blaine Avenue NE. Mr. Colt stated that the planned temporary access for equipment access is on a road constructed by ERADCO, American Memorial and Mt. Olivet. He asked if the applicant had any easements or agreements with the property owners. Ms. Pinard explained that the area would be used temporarily for construction purposes during Phase 1. The,property itself belongs to Puget Power. M.A. Segale, Inc. has had an understanding with Puget Power for many years and has the right to cross the property. Mr. Colt stated that he has an easement from Puget Power for this area and a letter from the City of Renton that says he has exclusive rights to cross the property. Ms. Pinard commented that Puget Power advised M.A. Segale that they were not aware of any easements across their property that would restrict M.A. Segale from crossing. She noted that it does not seem possible that the City can restrict a person's right to use Puget Power's property, based on a letter. The Examiner asked if the applicant can achieve access to the site via the proposed Edmonds access. Mr. Watts stated that it is possible. Referring to the restrictions of APA Zone 1, Mr. Colt stated that Mt. Olivet has recorded water rights on the subject property, and the file on this application indicates there is no water on the site. Mr. Colt then introduced three aerial photographs dated 1987, 1988, and 1990, stating that he does not currently have a more recent photograph. Responding to Mr. Colt's comments, Mr. Watts explained that the site's water quality features DANA WARREN,M.A.SEGALE,INt.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 7 must be lined. Runoff from any street will run through a wetpond for treatment before it is discharged back to the Aquifer. On this site, there are lined wetponds and bioswales that will not allow infiltration. Then there is a series of detention ponds and infiltration ponds. There will be 100% recharge of site runoff. Ms. Pinard noted that their research on water rights turned up a June 1974 application for a water claim. They did not locate a confirmation of water rights. She understands Mr. Colt the right to use a specific number of gallons per minute for irrigation purposes. M.A. Segale gave consideration to this situation and treatment is provided in the project to protect the claimed water rights. Mr. Colt asked if installation of the stormwater filtration facilities will be accomplished prior to filling, grading and compaction of 750,000 cubic yards of fill material? What is the schedule that has been designed to protect the Aquifer? Noting that the staff report states that stormwater will be collected and placed into ponds, he asked if there are there provisions to prevent fertilizers, pesticides, oil runoff, and other things from entering the groundwater system? GARY HENDERSON, 6240 Tacoma Mall Boulevard, Suite 318, Tacoma, WA 98049, responded to Mr. Colt's questions on the water issues. He stated that site run-off water will flow through wetponds and treatment swales. This will purify the water and leave the impurities in the wetponds. The water would then flow to an infiltration system that recharges the water. Last September and October, his company performed field work and prepared a report. At that time there was water on the site and they have not ever represented that there is no water on site. Much of the rain that falls on site collects on the property and then discharges into a stream or perks into the ground. It then leaves the site through groundwater seepage. Some surface water also flows onto site from the higher areas. On this site,the developer has established criteria to keep all water flowing as it is now. There will be no reduction in the current flow of water from the site. In regard to compaction of fill material, a criteria has been established to avoid settlement and there will be compaction under recharge areas. Infiltration systems will have to be installed as the site is graded. They have recommended that temporary storage and percolation facilities be constructed during site development. Using permanent facilities would increase the risk of silt build-up problems in the permanent facilities. After construction is complete, water would be directed into permanent facilities. Mr. Henderson noted that a gravely sand has been specified for some areas that is permeable, even when compacted. Mr. Watts noted that all drainage provisions for the project will be in compliance with the King County Surface Water Manual, which includes providing drainage facilities as the project is constructed. Temporary facilities are needed because of sedimentation problems that develop from construction. Mr. Colt asked how will the Codes, Covenants and Restrictions(CCRs) impact the surrounding neighbors and property owners? The Examiner explained that CCRs specifically apply to the project and its residents. They do not effect the general public. Ms. Pinard noted that the CCRs are for the people living within the site. The CCR parking conditions apply only to this project. Responding to Mr. Colt's comments regarding the flow of stormwater from the site, Mr. Watts explained that the rate of flow cannot be changed. He noted that the rate of flow is not equivalent to the amount of flow. The rate of flow is fixed, the amount of flow can be changed by the amount of rain fall. The Examiner called for further testimony regarding this project. There was no one else wishing to speak, and no further comments from staff. The hearing closed at 12:28 p.m. DANA WARREN,M.A.SEGALE,Ih.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 8 FINDINGS, CONCLUSIONS & DECISION Having reviewed the record in this matter, the Examiner now makes and enters the following: FINDINGS: 1.The applicant, Dana Warren for M.A. Segale, Inc., filed requests for approval of a 402 unit mobile home park, a conditional use permit for recreational vehicle parking, and a variance from the side yard setbacks. 2.The yellow file containing the staff report, the State Environmental Policy Act(SEPA)documentation and other pertinent materials were entered into the record as Exhibit No. 1. 3.The Environmental Review Committee(ERC), the City's responsible official, issued a Determination of Non-Significance- Mitigated (DNS-M) for the subject proposal. The applicant has not yet strictly met some of the ERC's conditions. 4.The subject proposal was reviewed by all departments with an interest in the matter. 5.The site is located southeast of the intersection of NE 3rd Street and Edmonds Avenue NE. The King County shop site is located east of the site. Mt. Olivet cemetery is located west of the site. The Maple Valley Highway is south of the property, below the site's steep southern slopes. 6.The subject site was used extensively over the years as a gravel quarry. 7.The subject site is an L-shaped parcel. The western, north-south leg of the "L" is approximately 3,000 feet long. It varies from approximately 900 feet to 1,300 feet wide. The southern, east-west leg of the L" (base) is approximately 2,600 feet long. This section is approximately 1,300 feet wide. The parcel is approximately 133.29 acres in area. 8.The topography of the site is very complex as a result of the extensive quarrying efforts that carved out deep pits while leaving steeper sidewalls, as well as the natural slopes that drop down to the Cedar River(Maple Valley Highway)on the south. The applicant proposes extensive regrading efforts to create level terraces for development while following very specific engineering standards to protect the various slopes. 9.Two power lines cross the property. One line runs north to south near the west margin of the site. The second line transects the property on a diagonal that runs more or less across the intersection of the two legs of the L-shaped parcel. 10. The site is zoned RM-H (Residential Manufactured Homes)and RC (Resource Conservation). 11. The map element of the Comprehensive Plan designates the area in which the subject site is located as suitable for the development of single family uses, but does not mandate such development without consideration of other policies of the Plan. 12. The applicant proposes developing a park for manufactured housing(mobile homes). The site would contain pads for 402 homes. In addition,there will be a community building and a separate parking lot for recreational vehicles. DANA WARREN,M.A.SEGALE,Ih.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CUN/MHP/ECF May 23, 1995 Page 9 13. The lots would be leased to purchasers. The homes will be manufactured off-site and will be privately owned. Common elements of the site including access roads, landscaping between parcels and along the frontage of internal roadways and in front yards will be installed and maintained by the applicant. The typical lot would be approximately 4,567 square feet in area. 14. The applicant anticipates that approximately 750,000 cubic yards of material will be graded on the site. Approximately 75,000 cubic yards of materials will be imported to the site. The remaining yardage will be redistributed to create level areas for future construction. The applicant will be required to observe a 25 foot setback from the eastern slopes and 40 feet on the western slopes. In addition, strict reporting will be required on the nature and source of fill materials to insure that they are suitably clean and appropriate. 15. The subject site straddles Zones 1 and 2 in the City's Aquifer Protection areas. The presence of the aquifer recharge area dictates strict standards in what fill materials can be imported on the site (see above)as well as the nature of types of uses and materials that can be stored on the site. In addition, because this is a recharge area, all stormwater that lands on the site will be treated and discharged into the soils by infiltration. 16. Water will be collected from the entire site and channeled to detention systems located in Zone 2. One detention system will be located under the powerlines that run diagonally through the center of the site. Another section of the system will be near the northeast corner of the site. Directly west of that system will be another system near the west boundary of the site. 17. The applicant proposes phasing the project over about ten (10)years. There will be four phases. Development will progress from the north to the south and then west to east. The development is divided almost equally in quarters. The community center and recreational vehicle parking component will accompany Phase 1. Phase 1 will include the necessary access road from NE 3rd, the new southern extension of Edmonds Avenue. If the western upright of the "L" were divided into thirds, Phase 1 would be the northern third of the "L." The Community Center will be located at the southwest corner of Phase 1. Phase I will contain 100 homes. 18. Phase 1 will also construct what will be the western access road. This roadway is necessary to create a loop roadway that will provide emergency access in the event Edmonds Avenue is blocked. All grading will occur with the development of Phase 1. 19. Phase 2 will begin approximately two years later. It will also contain 100 homes. It will be in the center of the "L's" upright. 20. Phase 3 will be located at the crook in the "L" at the southwest corner of the parcel. It will contain somewhat more than 100 homes. 21. The final phrase, Phase 4,will be at the eastern end of the base of the "L." This portion of the site is located south of the King County shop site and transfer station property. It will contain the remaining homes, approximately just under 100 homes. 22. Phases 1 and 2 are primarily single wide units while Phases 3 and 4 will contain a mix of single and double-wide units. Units will be developed at a rate of approximately 5 to 6 units per month. 23. The single units will vary in size from approximately 28 feet wide by between 42 and 66 feet long. The larger units will be approximately 41 feet wide. Each unit will have a two car garage. The units will be brought to the site in two or three sections. DANA WARREN,M.A.SEGALE,I\.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 10 24. As noted there will be a community building in the northwest corner of the site. The building will be approximately 4,500 square feet. If the variance is approved there will be private open space on each lot. The powerline corridors and detention systems provide relief from the sprawling housing plots. 25. The applicant proposes developing a parking lot for 100 recreational vehicles. The proposed lot would be located west of the Phase 2 section of the property, along the western edge of the site. The parking would be developed under the powerline corridor. The proposed parking lot requires a Conditional Use Permit. 26. An approximately 3,000 square foot landscape maintenance building would be located at the southeast corner of the RV lot. 27. The site is served by the City of Renton which will provide domestic water and sewer service. 28. The site is located within the Renton School District. The development is intended to serve older residents and is not expected to generate a student population. 29. In addition to developing an approximately 500 foot long section of Edmonds Avenue, the applicant will provide an emergency access to the west to Blaine Avenue NE. That roadway provides primary access to Mt. Olivet Cemetery and the Monterey Terrace neighborhood. As proposed that access will be gated and reserved solely for access by emergency vehicles. There seems to be some confusion over what was required by the ERC as to what development standards apply to that portion of Edmonds south of the main entry gate regarding the amount of dedication and nature and timing of improvements. No permit for development shall be approved until an agreement is executed in writing regarding these issues. 30. Within the complex, all roads will be private. They will be 30 feet wide and 5 foot sidewalks will be provided on one side of these roads. There will be a security gate at the entrance to the complex. 31. The applicant has requested a variance to allow less than the required side yard. The applicant has proposed placing the garages along the side of the residential units. This would create an L-shaped building footprint. The main residence would form the upright of the "L" and the garage would form the lower leg of the "L." The garage would be setback only 3 feet from the property line whereas the code requires a 5 foot minimum setback. What this design does is permit the creation of an approximately 25 foot wide private yard in the crook of the "L." This design would provide an 8 foot separation between units for the 25 foot depth of the garage, but a 28 foot separation for the remaining lot depth. 32. The applicant claims that the loss of developable acreage due to the steep slopes and powerlines does not permit it to separate units as widely if it were required to provide the full five foot setback on each lot. The resulting design would move the garage to the front of each residence, creating a "flatcar" footprint. It would be less creative and while it would provide 10 feet of separation between units it would eliminate the private yard. 33. The lots range in size from approximately 55 feet wide to approximately 85 feet long. 34. The proposed density will be approximately 5.65 units per acre. DANA WARREN,M.A.SEGALE,In... CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 11 35. The proposed units will have a footprint that covers less than 50 percent of each lot. The RM-H Zone permits 50 percent lot coverage whereas the Mobile Home Park development standards provide for lot coverage of 40 percent. 36. Automated lighting systems with long-life bulbs will be installed and maintained by the applicant to provide on-site lighting. 37. The applicant will be grading the entire site, but development will be phased over approximately ten 10)years. This will leave exposed, raw looking slopes and open spaces. 38. The applicant's proposal is not anticipated to interfere with existing water rights. The proposed recharge system is intended to maintain the existing aquifer recharge. CONCLUSIONS: Mobile Home Park 1.The applicant for a mobile home park must demonstrate that it meets minimum standards and criteria Section 4-11-5A)enumerated in part below: 4-11-5A1. Site: The minimum site shall be two (2)developable and usable acres. 4-11-5A2. Access: There shall be at least two(2)places of access of which at least one public access must be on a major or secondary street as defined by the City comprehensive arterial and street plan. 4-11-5A3. Screening: A solid wall or view-obscuring fence, hedge or equivalent barrier not less than five feet(5') in height shall be established and maintained around the entire periphery of the park except for openings for driveway and walkway purposes. 4-11-5A4. Permanent Dwelling: The only permanent dwelling allowed on the mobile home park shall be the single family dwelling of the owner or manager. 4-11-5A5. Lot Size: Each mobile home lot shall contain a minimum of three thousand(3,000) square feet, with the length of not less than seventy five feet(75')and the width not less than forty feet(40'). Each lot shall be laid out so as to optimize view, privacy and other amenities. 4-11-5A6. Density: There shall be not more than eight(8)lots per gross acre of the mobile home park. (Ord. 3746,9-19-83) 4-11-5A7. Setbacks: Each lot shall be clearly defined and landscaped. Mobile homes together with any accessory structures, including patios, awnings and related devices shall be located a minimum of ten feet(10')from the front lot line; five feet(5')from side or rear lot lines; and ten feet(10')from another mobile home measured closer than twenty feet(20')to any public street or highway. It shall be illegal to allow or permit any mobile home to remain in the mobile home park unless a proper space is available for it. (Ord. 3902, 4-22-85) 4-i 1-5A8. Lot Coverage: No more than forty percent(40%)of any lot shall be covered by a mobile home and enclosed accessory structures. In addition accessory structures such as carport DANA WARREN,M.A.SEGALE, CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 12 canopies or patio covers having less than fifty percent(50%)perimeter wall enclosure shall not exceed twenty percent(20%)coverage of any lot. 4-11-5A9. On-Site Private Streets, Curbs and Sidewalks: Asphaltic or concrete streets and concrete curbings shall be provided to each lot. The minimum width of streets shall be thirty feet 30'). Concrete sidewalks of at least five feet(5') in width shall be placed along at least one side of each street or located in the back or side of each lot so that there is sidewalk access to all lots. 4-11-5A10. Parking: Each mobile home lot shall have a minimum of two(2)off-street automobile parking spaces. Mobile home parks shall provide screened parking for boats, campers, travel trailers and related devices on a ratio of one space per ten (10) lots, in a secluded portion of the park. 4-11-5A11. Recreation Area: A minimum of ten percent(10%)of the total area of the park shall be reserved and shall be used solely and exclusively for a playground-recreation area. 4.11-5Al2. Illumination: The Public Works Department shall approve a street lighting plan providing sufficient illumination between sunset and sunrise to illuminate adequately the roadways and walkways within a mobile home park. 4--11-5A13. Landscaping: Landscaping shall be provided on both the individual lots and the remainder of the mobile home park site according to individual lots and the remainder of the mobile home park site according to a landscape plan approved by the Hearing Examiner. 4-11-5A13a. Installation: A surety bond of not less than four hundred dollars($400.00)per acre of the mobile home for a maximum of two(2)year period guaranteeing to the City the installation according to the approved landscape plan of walls, fences and landscaping required herein shall be posted prior to the issuance of any permits to construct the park. 4-11-5A14. Public Street Improvements: On or off-site public street improvements shall conform to the provisions and requirements of the subdivision ordinance, Title 9, Chapter 12. 4-11-5A15. Patio: A concrete patio on each mobile home lot of not less than one hundred twenty five(125)square feet with a minimum width of eight feet(8')shall be provided. 2.The site, at 133 acres, exceeds the minimum two(2)acres. The site is located adjacent to NE 3rd Street and Edmonds Avenue NE will be extended. Both streets provide the necessary access to a major or secondary street. 3.The topographic separation provided on much of the site makes the provision of a view-obscuring fence superfluous. There would not be much screening affect where severe slopes and the mandated setback already remove from view the interior of the complex. 4.The manufactured homes are not necessarily permanent homes as apparently envisioned by the code. The proposed dwellings are situated on leased lots thereby lacking any sense of permanency; as that term is usually employed. DANA WARREN,M.A.SEGALE, CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 13 5.The parcels all meet or exceed the dimensions required. The layout is appropriate (see variance below) given the proposed density of the complex. In addition, the overall density is 5.65 which meets the requirement that the complex not exceed 8 units per acre. 6.As noted, the applicant has requested a variance but meets the remaining setback distances. 7.The site meets the applicable lot coverage standards. As noted above, the site is governed by two standards and is entitled to meet the less rigid standard. 8.The applicant will be providing the required 30 foot wide internal street system and the required 5 foot wide sidewalk. 9.The provision of two-car garages for each unit meets the standard off-street parking requirements. In addition, the driveway can accommodate additional vehicles if necessary. The requisite recreational vehicle parking(see Conditional Use Permit below) in excess of the requirements will be provided in an appropriate area. 10. The applicant will be providing approximately 7.1 acres for recreation, including the approximately one 1) acre community center site. Staff apparently used net acreage due to the topographical limitations. Other than the community center, most of the recreational opportunities are walking trails and passive areas. 11. The Public Works Department has approved the lighting plan. 12. The applicant has submitted a landscape plan and the ERC required supplemental landscape treatment. In addition, as noted, there does not seem to be an adequate plan to treat the denuded areas of the site that will not be immediately developed. The phasing of development over ten years could leave vast amounts of acreage that will be subject to erosion by wind and water, large amounts of fugitive dust and a generally unsightly visage. Therefore,the applicant will have to hydroseed all portions of the site immediately after grading and all areas shall be mowed, watered and maintained on a regular basis. If any phase lags more than four years after the start of any prior phase,the applicant shall landscape with trees, shrubs and ornamental plantings those areas that are not developed as originally proposed. The applicant will have to post the necessary surety bonds prior to the issuance of any development permits. 13. The applicant has not completed the necessary plans nor received approval of its street improvement plans. The applicant shall develop Edmonds Avenue as required by the City. All plans shall be submitted and approved in writing before any permits for development are issued. 14. The appropriate private patio areas are provided by the proposed plans. 15. There are a number of construction related requirements that will have to be met but those are not necessarily land use provisions for review during this proceeding. The applicant shall be required to meet all construction standards. Conditional Use Permit for Recreational Vehicle Parking Lot 16. The applicant for a Conditional Use Permit must demonstrate that the use is in the public interest, will not impair the health, safety or welfare of the general public and is in compliance with the criteria found in Section 4-31-36 (C)which provides in part that: a.The proposal generally conforms with the Comprehensive Plan; DANA WARREN,M.A.SEGALE,In.. CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 14 There is a general community need for the proposed use at the proposed location; c.There will be no undue impacts on adjacent property; d.The proposed use is compatible in scale with the adjacent residential uses, if any; e.Parking, unless otherwise permitted, will not occur in the required yards; f.Traffic and pedestrian circulation will be safe and adequate for the proposed project; g.Noise, light and glare will not cause an adverse affect on neighboring property; h.Landscaping shall be sufficient to buffer the use from rights-of-way and neighboring property where appropriate; and i. Adequate public services are available to serve the proposal. The requested conditional use appears justified and is approved. 17. The proposed RV parking area is required by Ordinance, although the size of the proposed lot does mandate conditional use review. The mobile home park it serves is in conformance with the Comprehensive Plan. The accessory parking lot is,therefore, appropriate. 18. The senior community that will occupy this development generally seem to use RV's. There is a demand to have the RV parking area conveniently located and appropriately screened. Market surveys demonstrate a need for a RV parking area in senior communities. The placement of the parking area is obviously tied to the overall complex. 19. There does not appear to be any more appropriate location for this lot. While it is separated from the residential complex it could affect the residential community proposed to its west. The applicant does propose screening to offset any visual impacts. 20. The low-rise nature of the vehicles that will be stored on the lot should blend with surrounding uses. There will be no appreciable impact on adjacent uses. 21. Other than the RV parking,there will be no additional parking, accessory uses or utility requirements. 22. The screening proposed will limit the spill of noise and light off the site to adjoining parcels. Variance from Side Yard Setback 23. Variances may be granted when the property generally satisfies all the conditions described in part below: a.The applicant suffers undue hardship caused by special circumstances such as: the size, shape, topography, or location where code enforcement would deprive the owner of rights and privileges enjoyed by others similarly situated; b.The granting of the variance would not materially harm either the public welfare or other property in the vicinity; DANA WARREN,M.A.SEGALE,In... CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 15 c.The approval will not constitute a special privilege inconsistent with the limitations on other property in the vicinity; and d.The variance is the minimum variance necessary to allow reasonable development of the subject site. The applicant's property appears ripe for the variance requested. 24. The main constraint on normal development of the site is that severe slopes have limited the developable portions of the site substantially. Given this limitation, the applicant has scaled back the number of units but provided for more open space between units. 25. In addition, the design and layout the applicant has proposed is more aesthetic. It provides more privacy, not less between units, and definitely more reasonable useable space. 26. The terrain separation as well as the substantial setbacks of development from the property line protect the adjoining property and the general welfare from any material harm. 27. The unique nature of the site would prevent other property from challenging the precedent setting nature of the granting of this variance. The site is quite unique and therefore, approval will not create an undue precedent. 28. The variance appears to be the minimum which will achieve the purpose of allowing reasonable development of the subject site. 29. In conclusion, the proposed use will create a unique housing complex that will provide additional housing choices to a particular segment of the community and it will do so in a fitting manner and style. DECISION: The Mobile Home Park, Conditional Use for Recreational Vehicle Parking Lot and Variance from Side Yard Setback are approved subject to the following conditions: 1.Applicant compliance with the conditions imposed by the ERC. 2.The applicant shall hydroseed all portions of the site immediately after grading and all areas shall be mowed, watered and maintained. If any phase lags more than four years after the start of any prior phase,the applicant shall landscape with trees, shrubs and ornamental plantings those areas which are not developed as originally proposed. 3.The applicant will have to post the necessary surety bonds for landscape installation and maintenance prior to the issuance of any development permits. 4.No permit for development shall be approved until an agreement is executed in writing regarding the installation, phasing and design criteria for Edmonds Avenue NE. The applicant shall develop DANA WARREN,M.A.SEGALE,IN... CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CUN/MHP/ECF May 23, 1995 Page 16 Edmonds Avenue NE as required by the City. All plans shall be submitted and approved in writing before any permits for development are issued. 5.The applicant shall be required to meet all construction standards. 6.Pursuant to Section 4-11-5B1 "No grading, construction or similar activities, except the clearing of land, shall be permitted until the Hearing Examiner has given approval to the final plan." No work shall commence on the site until all conditions have been complied with by the applicant. ORDERED THIS 23rd day of May, 1995. Y0-4441,,, FRED J. KA AN HEARING EXAMINER TRANSMITTED THIS 23rd day of May, 1995 to the parties of record: Hugh Caffman James L. Colt Steve Ercolini 3008 SE 5th Street 102 Monterey Place NE 3016 SE 5th Street Renton WA 98008 Renton WA 98056 Renton WA 98058 David Halinen Gary Henderson Jennifer Toth Henning 10500 NE 8th Street, #1900 6240 Tacoma Mall Blvd, #318 Project Manager Bellevue WA 98004 Tacoma WA 98049 City of Renton 200 Mill Avenue South Renton WA 98055 Lloyd Hoshide Lila Houser Thomas F. McMahon 833 Kirkland Avenue NE 57 Monterey Drive NE c/o Betts Patterson & Mines Renton WA 98056 Renton WA 98056 1215 4th Avenue, Suite 800 Seattle WA 98161 Mt. Olivet Cemetery Bruce Orff Mr. & Mrs. Richard Petterson do James L. Colt 2930 SE 5th Street T&E Investment PO Box 547 Renton WA 98058 1401 Lincoln Avenue NE Renton WA 98057-0547 Renton WA 98056 Ken Ponder Laurie Pinard Sunrise Land Corporation 2938 SE 5th Street M. A. Segale, Inc. PO Box 98638 Renton WA 98058 PO Box 88050 Seattle WA 98198 Tukwila WA 98138 DANA WARREN,M.A.SEGALE,IN . CEDAR CREST MANUFACTURED HOME PARK File No.: LUA-95-023,CU/V/MHP/ECF May 23, 1995 Page 17 Dana Warren Neil Watts American Memorial Services M.A. Segale, Inc. Plan Review Supervisor P.O. Box 1745 PO Box 88050 City of Renton Bellevue, WA 98009 Tukwila WA 98138 200 Mill Avenue South Renton, WA 98055 TRANSMITTED THIS 23rd day of May, 1995 to the following: Mayor Earl Clymer Councilman Richard M. Stredicke Members, Renton Planning Commission Gregg Zimmerman, Plan/Bldg/PW Administrator Art Larson, Fire Marshal Jim Hanson, Development Services Manager Lawrence J. Warren, City Attorney Mike Kattermann, Technical Services Manager Transportation Systems Division James Chandler, Building Official Utilities System Division Jay Covington, Mayor's Executive Assistant Valley Daily News Pursuant to Title IV, Chapter 8, Section 15 of the City's Code, reguest for reconsideration must be filed in writing on or before 5:00 p.m.,June 6, 1995. Any aggrieved person feeling that the decision of the Examiner is ambiguous or based on erroneous procedure, errors of law or fact, error in judgment, or the discovery of new evidence which could not be reasonably available at the prior hearing may make a written request for a review by the Examiner within fourteen(14)days from the date of the Examiner's decision. This request shall set forth the specific ambiguities or errors discovered by such appellant, and the Examiner may, after review of the record, take further action as he deems proper. An appeal to the City Council is governed by Title IV, Chapter 8, Section 16, which requires that such appeal be filed with the City Clerk, accompanying a filing fee of$75.00 and meeting other specified requirements. Copies of this ordinance are available for inspection or purchase in the Finance Department, first floor of City Hall. If the Examiner's Recommendation or Decision contains the requirement for Restrictive Covenants, the executed Covenants will be required prior to approval by City Council or final processing of the file. You may contact this office for information on formatting covenants. The Appearance of Fairness Doctrine provides that no ex parte(private one-on-one)communications may occur concerning pending land use decisions. This means that parties to a land use decision may not communicate in private with any decision-maker concerning the proposal. Decision-makers in the land use process include both the Hearing Examiner and members of the City Council. All communications concerning the proposal must be made in public. This public communication permits all interested parties to know the contents of the communication and would allow them to openly rebut the evidence. Any violation of this doctrine would result in the invalidation of the request by the Court. The Doctrine applies not only to the initial public hearing but to all Requests for Reconsideration as well as Appeals to the City Council. 6j— e.: N. I. 1,• 1?,.;.. 1;... . 4... 13..:;..... 1r.'. i. 1 I r,. 4 gal 1 i\ . t ''' N7' 41_ s. w, ; ...... - ) L.‘-. \ ' SII 4a! 71444 0. 4111 1 ,..;, t•:• . 2 ..: ' . ti tle* V.'. 4; + ' I, u, IDLl10l Ira oli---.'C '.! 5-ks. 1-''".•'')' iI‘T\\ 1 > e•..* 4, 4. 44 4 7 4 vitas•° gwcogf WO iSI a. 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