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HomeMy WebLinkAboutReport 2 - 1 of 71. PROJECT OVERVIEW: Evendell is located between 156 1 h Avenue SE and 1601 h Avenue SE on the south side of the unimproved ROW of SE 1361h Street within Section 14, Township 23N, Range SE in King County, Washington. See attached vicinity map. The 13.8-acre property is currently occupied by two single-family residences with associated outbuildings. Existing ground cover consists of a combination of forest, pasture, lawn, and landscaping. A wetland is also located at the northeast comer of the site. A boundary line adjustment will be completed to except one existing residence located along 1561h Avenue SE. The second residence will be included within a proposed lot within the development. Proposed development of the property will include the demolition of all structures on the property except for the excepted residence and the house within proposed Lot 52 and construction of 70 proposed single-family lots, 69 new and I existing residence lot, along with associated open space, roadway and utilities. Along with site improvements, an 8' wide shoulder will be added to l 60'h Avenue SE and SE 136 1h Street will be constructed through the existing unimproved ROW along the property's frontage. A drainage basin ridge runs through the property separating the onsite drainage into two drainage basins. On-site generated runoff will be directed to one of two detention/water quality facilities. A small amount of upstream area is tributary to the eastern portion of the site and will be routed through the detention/water quality facility. Level 2 Flow Control will be utilized for the East Basin along with downstream improvements. Level 3 Flow Control will be utilized for the West Basin. Both basins will be treating the drainage with Basic Water Quality Treatment. King County Department of Development and.Environmental Services TECHNICAL INFORMATION REPORT (TIR) WORKSHEET ParU .·P.ROJECTOWNERAND- PROUECTENGINEER . . . :· . ···,,i.,:·:-.. -.. Project Owner SRI Developing, I,I,C Address PO Box 73790, Puyallup, WA Phone 253-539-8116 Project Engineer David Cayton. P.E. Company Core_ Design, Inc. Part 2 PROJECT LOCATION AND DESCRIPTION. Project Name Evendell Location Township __ 2~3~N __ _ Range SE ............. Section ___ 1_4 ___ _ Address/Phone14711 NE 29th Pl, Se 101, Bellevue, WA 425-885-787' x Subdivison Short Subdivision Grading Commercial Other ________ _ PartA .OTHER REVIEWS AND PERM.ITS DFW HPA Shoreline Management COE 404 (Rockery '\ DOE Dam Safety <'Structural Vaults) FEMA Floodplain Other COE Wetlands Part 5 SITE COMMUNITY AND.DRAINAGE BASIN . Community Ni:::i.wc~ .... -1-1 o Drainage Basin Lower .. Cedar River Part6}plTE···~W,flACTERIST1pS·. . River Stream __________ _ Critical Stream Reach Depressions/Swales Lake-'-----------~ Steep Slopes--------- Floodplain ________ _ Wetlands __ ..,Jt'c:!-____ '--- Seeps/Springs High Groundwater Table Groundwater Recharge Other __________ _ ParVi SOl[S . . . ;. ' .. ":~ Soil Type Alderwood (AGC) Slopes 6-15% Additional Sheets Attached . ,. . .Part 8. DEVEL:OPMENTLIMITATIONS REFERENCE Ch. 4 -·oownstream Analysis Additional Sheets Attached . Erosion Potential Moderate Erosive Velcoties LIMITATION/SITE CONSTRAINT . ~----------~-----------------'-------_j Part 9 ESC REQUIREMENTS . MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Sedimentation Facilities Stabilized Construction Entrance Perimeter Runoff Control Clearing and Graing Restrictions Cover Practices Construction Sequence Other MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize Exposed Surface Remove and Restore Temporary ESC Facilities Clean and Remove All Silt and Debris Ensure Operation of Permanent Facilities Flag Limits of SAO and open space preservation areas Other " ... _.·,: ··. ·' ' ., .· ... " · ... Pardo< SURFAyl=WATER S)'.STEM . Grass Lined Tank Infiltration Method of Analysis Channel G0 Depression SBUH (:Pipe System"") Compensation/Mitigati Energy Dissapator Flow Dispersal on of Eliminated Site Open Channel Wetland Waiver Storage Dry Pond Stream Regional {vvetPond) Detention Brief Description of System Operation Developed drainage collected in pipe /catchbasin system and treated in detention/water quality Facility Related Site Limitations facilities on-site. Reference Facility Limitation Part 11 · STRUCTURAL ANALYSIS (cast in Place Vault) Retaining Wall C§"ockery > 4' Higi0 Structural on Steep Slope Other Part12 EASEMENTS/TRACTS rainage Easement Native Growth Protection Easement Other . Part 13 SIG.NATURE OF PROFESSIONAL ENGINEEl'l I or a civil engineer under my supervision my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the atiachments. 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', i :.-r. ·\>;·- ····---· ··,,, ·., .... ,?~~:\,···: . ·:~:·,--.,·-~ ""~: ~ .. ·• .... , \ Haozous Engineering CIVIL ENGIIEERING 1'4816 SE U6TH ST, RENTON, VA 980:59 '42S-235-2707 _ .. DATO &Ill 8/12/02 ........ DATO E.JM 8/12/02 1,1' . .... · '•. 'J; '(.,,) .... _ ; 1( '. c."t:-~t !~ 4~g·~ ti ")''''' .. .,., ... ,·~1,r,·~~~:.~\~">-:>( -·:~.::.:.>::·:· .. ,,.,,_,. .,.,...,.~ ..... ., \ _/ .~&dlon C.O of tK.15. . ~povt-:Ser A~.· SITE IS 97. OF TRIBUTARY AREA PROJECT NO. EVENDELL PLAT FlGUR· Drainage Basins 2 £ sad,{1 .JaAoJ/asn puo1 3NOOU "ON lOJrO!ld J..V1.d 113CTN3A3 ZO/tl/8 .. """' ffl'3 ..... ZO/Zl/8 nl'.l .... .. _ LOL2-sc2-g;. 6i;;.oe& ¥/\ 'Na.um • is H19n 1s 9t81't !JNil:IDNIDN3 1IAI:I ~UJJ:00UJ1h:13 BilOZOlJH 133J NI 31VJS lEzd 't -<-;,.*+ oo• ooa ··.;; , ' •, --; . . .. •i .. "' : .. .. . . r. . : . : . : 0 •• ' I slf' AGRICULTURE KING COUNT:ON SERVICE (RENT • • " . " ' -:, ·I I ...... AaC . . : . : i : --.....:.1.1 :· .- ... 11 ... ... .. ... I . . : I . .: = m, .... :;.:1.:.::·· ·. ,::···· I •• • "'==:db;!~~ I I A,iC I I .. . .. . . ··~ . . .... . .. c..,,_II'-. ~ tr~ : : . : . . .. I I . . . . . . ....... . . . : .. ~./ Ml. TO U.S.10 I • I •••• I • • • I KING COUNTY SOIL SURVEY EVENDELL CORE PROJECT NO. 04009 2. CONDITIONS AND REQUIREMENTS SUMMARY: Listed below are the Hearing Examiner's Conditions. The postmaster approval is included in Section 6 of this report. Attached at the end of this section is an email between Kurt Wilson (developer) and Corey Thomas (City of Renton Fire) regarding the emergency access cable and/or chain gate option, a copy of the SWM Adjustment L02V0024, and a copy of the title report regarding drainage easement. The preliminary plat revision ofEvendell, as received October 1, 2003, is APPROVED, subject to the following conditions for final plat approval: I. Compliance with all platting provisions of Title 19 of the King County Code. To be address during final plat. 2. All persons having an ownership interest in the subject property shall sign on the face of the final plat a dedication which includes the language set forth in King County Council Motion No. 5952. To be address during final plat. 3. a. The plat shall comply with the maximum density (and minimum density) requirements of the R-4 zone classification. All lots shall meet the minimum dimensional requirements of the R-6 zone classification or shall be as shown on the face of the approved preliminary plat, whichever is larger, except that minor revisions to the plat which do not result in substantial changes may be approved at the discretion of the Department of Development and Environmental Services. To be address during final plat. b. The Applicant shall provide transfer of density credit documentation to DDES prior to final approval to allow transfer of a maximum of 20 density credits to achieve a maximum of 70 lots on the subject property. To be address during final plat. 4. All construction and upgrading of public and private roads shall be done in accordance with the King County Road Standards established and adopted by Ordinance No. 11187, as amended (1993 KCRS), subject to any variances that may be approved by the King County Road Engineer. Construction of the roads comply with KCRS. See sheet Cl.02 and C3.31 of the civil plan set for road sections and pavement design. 5. A Boundary Line Adjustment (BLA) shall be completed prior to final plat approval to except from the plat that portion of the 200 (approximate) feet on the far west that is not part of the proposed plat. Documentation demonstrating the resolution of boundary issues with the property to the south (Nichols Place) also shall be provided to DDES. To be address during final plat. 6. The Applicant must obtain the approval from the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17 .08 of the King County Code. Joint Use Development Tract Has shown on the plat will provide access to Lots 28 and 29. Additionally, it is a future emergency vehicle access tract to and from 160'h Avenue SE, which the Applicant proposes to create in response to concerns raised by the City of Renton. The Applicant shall include proposed protocols for the construction and maintenance of Tract H, plus any related plat notes, with its engineering plans submittal, meeting the following standards: The emergency vehicle access to 160"' A venue SE shall have a minimum driving surface width of 20 feet, with an all-weather surface capable of supporting 25 tons. Any locking device shall be approved by the Renton Fire Department (KCFD # 25). Chains, cable or bollards will not be permitted. The gate shall be located at least 50 feet from 160"' Avenue SE to allow space for fire apparatus to stop while opening the gate or to wait before entering the public roadway. If these conditions are not met any future residence constructed on Lots 28 and 29 will have to be sprinklered NFPA 13D. These requirements concerning adequate fire and emergency access may be modified in a manner approved by the King County Fire Protection Engineer and King County Fire District no. 25. Approval of the fire hydrant placement is attached on the following page. See sheet CJ.02 of the civil plan set for Tract H road section. The Renton Fire Department is okay with a cable or chain within the emergency vehicle access per the attached email located at the end of this section. Also the cable or chain can be located 50 'from the edge of the driving lane on J 6(/h or 61 'from the centerline of J 61Jh. ; , lO'!XJ. I Ntt7d 1:/3.1 lfM 17:JGN:IA:l NO.LN~lf dO }..11:) II -c::::::{~)= ,§ ~ ~ 8 ~ ~- <( @ ·=-=--n: I --· --~ ··~..:r,::- U 0 (/) =,I'H I m=; J " _., . , - 0 °' 0 ,! z ,~ ti ~ ~~ a:, ll ili ~ s i;, ls" I ;~., .,11:1:5 .., -"""' 31.., "' NOJS\,\3" "ON ---- 8. Drainage adjustment L02V0024 is approved for this project. All conditions of approval for this adjustment shall be met upon submittal of the engineering plans. All conditions required for the adjustment have been addressed. See the end of this section for a copy of the adjustment. See TI.R. for detention sizing which includes limiting release rates to existing conditions plus the addition of a 10%factor of safety. See TJ.R.for calculation of water quality volumes which includes the site improvements along with frontage improvements that are captured by the proposed drainage system. The two drainage tracts will be dedicated to King County during final plat. SEPA conditions have been addressed per Hearing Examiner's Condition I 9. 9. A drainage easement for the conveyance from the Tract N drainage facility to 156th Ave SE shall be provided upon engineering plan submittal. The drainage easement is attached within the title report for the property. See the end of this section for the title report. I 0. The following road improvements are required to be constructed according to the 1993 King County Road Standards (KCRS): a. The internal access road from SE 1361h Street to the beginning of the internal loop road shall be improved to the urban subcollector standard, except that portion on the west side between Lot 11 and Lot 12 is not required to be improved with a sidewalk. See sheet CJ.02 of the civil plan set for the I 58'• Ave. SE and Portion of SE 137" St. section and sheets C4.21 and C4.22for road centerline profiles. b. The internal loop road shall be improved to the urban subaccess road standard with sidewalks. on the outside frontage of the loop road. See sheet CJ.02 of the civil plan set for the Portion of SE /371 ' St., I 59'' Pl. SE, SE !38'h St., I 58'' Pl. SE section and sheet C4.2 I for road centerline profile. c. SE 136"' Street (frontage and offsite) shall be dedicated, designed and improved in general conformance with the Preliminary Road Improvement Plan received 3/26/2002 with the Plat ofEvendell: The frontage from 158th Ave NE to 160th Ave NE shall be improved to the urban one-half street standard. Eighteen feet of additional right-of way shall be dedicated for this improvement. See sheet CJ.02 of the civil plan set for the SE /361 • St (Between I 58'• Ave. SE and 16(/' Ave. SE) section and sheet C4.21 for road centerline profile. SE 136th Street frontage from the west side of J.U.D.T. 'A' boundary to 158th Ave NE shall be improved to the urban neighborhood collector standard; EXCEPT that no sidewalk construction is required on the north side. Twenty feet of additional right-of-way shall be dedicated for this improvement. See sheet Cl.02 of the civil plan set for the SE 136'' St (Between 1561 • Ave. SE and 158'• Ave. SE) section and sheet C4.21 for road centerline profile. SE 136'" Street from 156th Ave SE to J.U.D.T. 'A' shall be improved to the urban neighborhood collector standard; EXCEPT that no sidewalk construction is required on the north side. Twenty-six feet of additional right-of-way shall be provided for this improvement. An additional 25-foot right-of-way radius is required at the southeast corner of 156th Ave SE and SE 136th Street. Striping for a second westbound lane shall be provided within the 150-foot widened section approaching 156th Avenue SE, in a manner to be worked out at the time of submission of engineering plans. See sheet CJ.02 of the civil plan set for the SE 1361 • St (Between 156'' Ave. SE and 158'' Ave. SE) section and sheet C4.21 for road centerline profile. See sheet CJ.32 for striping of SE 1361 • Street. d. 160th Ave SE FRONT AGE: The 160th Ave SE frontage shall be improved with an 8- foot paved shoulder on the west side. Adequate provisions for road drainage shall be provided. See sheets CJ.OJ and CJ.31 for shoulder construction information and pavement section. Drainage will be conveyed either to the bypass ditch along 160'' or to the proposed drainage system. e. Tracts A,C,F,G,H, and I shall be improved to the joint use driyeway standard per Section 3.01 of the KCRS. Tract A shall include an easement to King County for the maintenance of the Tract N drainage facility. Tract A shall be owned and maintained by the owners of Lots I and 2. See sheet CJ.02 of the civil plan set for the Tracts A, C. F, H, & I section. Ownership and maintenance of tracts will be dedicated during final plat. f. Tracts B, D and E shall be improved to the private access tract standard per Section 2.09 of the KCRS. See sheet Cl.02 of the civil plan set for the Tracts B, D, & E section and sheet C4.22for road centerline profiles. g. The Applicant shall revise the channelization that has been constructed in conjunction with the plat of Highland Estates (LOOP0009). These modifications to the channelization shall incorporate a revision of the current proposed painted 'island' to a southbound left turn lane with at least 60 feet of storage for left turning vehicles to (a) encourage the use of 156th Avenue SE in lieu of 158th Avenue SE and 160th Avenue SE, and (b) mitigate the potential deficient condition that would result.from southbound left turning vehicles making left turns from the southbound through lane, or using the painted island as a deceleration and refuge area while waiting for gaps in northbound traffic. Channelization and illumination plans must be submitted to King County Traffic Engineering Section for review and approval of the turn lane channelization. Modifications to the above road conditions may be considered according to the variance provisions in Section 1.08 of the KCRS. See sheet CJ.32 of the civil plan set for the revised channelization and modification of the existing street lighting along 15 61 h Ave. SE. 11. There shall be no direct vehicular access to or from 160th Avenue SE from those lots which abut this street. A note to this effect shall appear on the engineering plans and final plat. To be addressed duringfina/ plat. See sheet CJ.OJ on the civil plan set for a duplicate of the above condition listed under "Hearing Examiner's Conditions". 12. All utilities within proposed rights-of-way must be included within a franchise approved by the King County Council prior to final plat recording. To be addressed during final plat. 13. The Applicant or subsequent owner shall comply with King County Code 14.75, Mitigation Payment System (MPS), by paying the required MPS fee and administration fee as determined by the applicable fee ordinance. The Applicant has the option to either: (I) pay the MPS fee at final plat recording, or (2) pay the MPS fee at the time of building permit issuance. If the first option is chosen, the fee paid shall be the fee in effect at the time of plat application and a note shall be placed on the face of the plat that reads, "All fees required by King County Code 14.75, Mitigation Payment System (MPS), have been paid." If the second option is chosen, the fee paid shall be the amount in effect as of the date of building permit application. To be addressed during final plat. 14. The proposed subdivision shall comply with the Sensitive Areas Code as outlined in KCC 21 A.24. Preliminary plat review has identified the following specific requirements that apply to this project. All other applicable requirements from KCC 21 A.24 shall also be addressed by the Applicant. a. This site contains a Class 2 wetland. The majority of the wetland will be protected from alteration during and after construction, with a 50-foot wide buffer around the wetland boundary. An additional 15-foot building setback is required beyond the edge of the buffer. See sheets CJ.OJ and C4.01 of the civil plan set for delineation of 50' wetland buffer and 15' BSBL. b. A maximum of 200 square feet of wetland will be filled for construction of SE 136th Street. Mitigation shall consist of at least 400 square feet of wetland enhancement to degraded portions of the existing wetland. Wetland Mitigation plans are currently under review. c. Road improvements for SE 136th Street and 160th Avenue SE will eliminate 6,989 square feet of wetland buffer. Mitigation shall consist of providing replacement buffer in the northeast portion of the site at approximately a 2: I ratio to provide additional protection for the wetland pursuant to KCC 21A.24.320B. Reduced impact will result in reduced mitigation. Wetland Mitigation plans are currently under review d. The proposed sewer main within the SE 136th Street right-of-way will intrude into the wetland buffer along with the road improvements. In order to protect wetland hydrology: (I) the sewer line shall be installed during the dry season (June through September), and (2) the design shall incorporate the use of pipe bed dams of bentonite or other material at intervals to preclude draining possible subsurface water flows through the gravel pipe bedding. Design of the proposed sewer force main adjacent to the wetland along SE 13 6'' Street has been designed with the required note and design of pipe bed dams adjacent to the wetland buffer. See Sanitary Sewer Plan set that will be approved through the City of Renton. e. Downstream drainage improvements to existing culverts and stormwater conveyances required through the SEP A MDNS shall cause no adverse alteration to existing wetlands or streams in the vicinity of the drainage improvements. Noted. f. Critical Areas staff shall review engineering plans for the plat and sewer main for conformance with these requirements. Noted. 15. The following note shall be shown on the final engineering plan and recorded plat: RESTRICTIONS FOR SENSITIVE AREA TRACTS AND SENSITIVE AREAS AND BUFFERS Dedication of a sensitive area tract/sensitive area and buffer conveys to the public a beneficial interest in the land within the tract/sensitive area and buffer. This interest includes the preservation of native vegetation for all purposes that benefit the public health, safety and welfare, including control of surface water and erosion, maintenance of slope stability, and protection of plant and animal habitat. The sensitive area tract/sensitive area and buffer imposes upon all present and future owners and occupiers of the land subject to the tract/sensitive area and buffer the obligation, enforceable on behalf of the public by King County, to leave undisturbed all trees and other vegetation within the tract/sensitive area and buffer. The vegetation within the tract/sensitive area and buffer may not be cut, pruned, covered by fill, removed or damaged without approval in writing from the King County Department of Development and Environmental Services or its successor agency, unless otherwise provided by law. The common boundary between the tract/sensitive area and buffer and the area of development activity must be marked or otherwise flagged to the satisfaction of King County prior to any clearing, grading, building construction or other development activity on a lot subject to the sensitive area tract/sensitive area and buffer. The required marking or flagging shall remain in place until all development proposal activities in the vicinity of the sensitive area are completed. No building foundations are allowed beyond the required 15-foot building setback line, unless otherwise provided by law. To be addressed during final plat. See sheet Cl.OJ on the civil plan set for a duplicate of the above condition listed under "Hearing Examiner's Conditions". 16. Suitable recreation space shall be provided consistent with the requirements KCC 21A.14.180 and KCC 21A.14.!90 in providing sport court[s), children's play equipment, picnic table[s], benches, etc. a. A detailed recreation space plan (i.e., landscape specs, equipment specs, etc.) shall be submitted for review and approval by ODES and King County Parks prior to or concurrent with the submittal of the engineering plans. This plan shall comply with Ordinance# 14045. See sheets Cl.OJ and Cl.02 of the civil plan set for the Recreational Park Plan. b. A performance bond for recreation space improvements shall be posted prior to recording of the plat. To be addressed during final plat. 17. A homeowners' association or other workable organization shall be established to the satisfaction ofDDES which provides for the ownership and continued maintenance of ' the recreation, open space and/or sensitive area tract(s). To be addressed during final plat. 18. Street trees shall be included in the design of all road improvements, and shall comply with Section 5.03 of the KCRS and KCC ZlA.16.050: a. Trees shall be planted at a rate of one tree for every 40 feet of frontage along all roads. Spacing may be modified to accommodate sight distance requirements for driveways and intersections. See sheet C7.03 of the civil plan set for the Street Tree Planting Notes. b. Trees shall be located within the street right-of-way and planted in accordance with Drawing No. 5-009 of the 1993 King County Road Standards, unless King County Department of Transportation determines that trees should not be located in the street right-of-way. See sheet C7.03 of the civil plan set for the Street Tree Planting Notes. c. If King County determines that the required street trees should not be located within the right-of-way, they shall be located no more than 20 feet from the street right-of- way line. See sheet C7.03 of the civil plan set for the Street Tree Planting Notes. d. The trees shall be owned and maintained by the abutting lot owners or the homeowners association or other workable organization unless the County has adopted a maintenance program. Ownership and maintenance shall be noted on the face of the final recorded plat. See sheet C7. 03 of the civil plan set for the Street Tree Planting Notes. Ownership and maintenance shall be addressed during final plat. e. The species of trees shall be approved by DDES if located within the right-of-way, and shall not include poplar, cottonwood, soft maples, gum, any fruit-bearing trees, or any other tree or shrub whose roots are likely to obstruct sanitary or storm sewers, or that is not compatible with overhead utility lines. See sheet Cl. 03 of the civil plan set for the Street Tree Planting Notes. f. The Applicant shall submit a street tree plan and bond quantity sheet for review and approval by DDES prior to engineering plan approval. See sheet C7.03 of the civil plan set for the Street Tree Planting Plan along with tree count quantities. g. The street trees must be installed and inspected, or a performance bond posted prior to recording of the plat. If a performance bond is posted, the street trees must be installed and inspected within one year of recording of the plat. At the time of inspection, if the trees are found to be installed per the approved plan, a maintenance bond must be submitted or the performance bond replaced with a maintenance bond, and held for one year. After one year, the maintenance bond may be released after DDES has completed a second inspection and determined that the trees have been kept healthy and thriving. A landscape inspection fee shall also be submitted prior to plat recording. The inspection fee is subject to change based on current County fees. To be addressed during final plat. 19. The following have been established by SEP A as necessary requirements to mitigate the adverse environmental impacts of this development. The Applicants shall demonstrate compliance with these items prior to final approval. a. East Drainage Basin: The 160th Ave SE downstream conveyance system shall be upgraded to provide for the I 00-year storm capacity. Downstream driveway culverts/ditches and a cross- culvert under 160th Avenue SE shall be improved as follows: Culverts P-117 and P- 116 on the west side of 160th Avenue SE, cross-culvert P-115, and culverts P-114 and P-113 on the east side of 160th Avenue SE shall be improved as needed. The culvert designations are according to the Level 3 Downstream Drainage Analysis by Haozous Engineering dated August 26, 2002. To address a related localized flooding condition, bank and channel stabilization are also required in the unopened right-of-way for 162"d Avenue SE, in the vicinity of the easterly line of Lot 12, Rich Lea Crest (address 16046 SE 142"d Street). It is estimated that stabilizing and re- grading approximately 50 to I 00 feet of channel, east of 16046 SE 142"' Street, will be adequate to resolve flooding that has occurred in the past location. The culverts and channel described are located from the south site boundary to a distance of approximately I, 700 feet downstream. Level 2 Flow Control design is required for the proposed stormwater detention facility. A factor of safety of 5 to 15 percent, determined by the design engineer, shall be required for detention storage volumes. Level 2 Flow Control was utilized for sizing of the East Basin wetpond. A 10%factor of safety was added per the minimum required as a condition of the Drainage adjustment L02V0024. Culverts Pl 15, Pl 14, and Pl 13 have already been replaced by others. Pl 15 is now a 24" N-12 and Pll4 and Pl 13 are both 30" N-12. Culvert Pll6 and Pll7 will be replaced as part of this development. b. West Drainage Basin: The stormwater detention facilities shall be designed to the Level 3 Flow Control Standard as described in the 1998 King County Surface Water Design Manual (KCSWDM). As an option, Level 2 Flow Control with downstream improvements can be proposed according to Core Requirement 2 of the KCSWDM. The minimum Flow Control Standard shall be Level 2. A factor of safety of 5 to 15 percent, determined by the design engineer, shall be required for detention storage volumes. The downstream impacts of the 1,700 feet of conveyance improvements shall be reviewed by the developer's engineer, and any recommendations necessary to prevent flooding or other damage from occurring as a consequence of the required conveyance improvements shall be included with the plans for review by DOES. Level 3 Flow Control was utilized for sizing of the West Basin wetvault. A 10% factor of safety was added per the minimum required as a condition of the Drainage adjustment L02V0024. School Mitigation Fees 20. Lots within this subdivision east of 158th Avenue SE are subject to King County Code 21A.43, which imposes impact fees to fund school system improvements needed to serve new development. As a condition of final approval, fifty percent ( 50%) of the impact fees due for the plat shall be assessed and collected immediately prior to recording, using the fee schedules in effect when the plat receives final approval. The balance of the assessed fee shall be allocated evenly to the dwelling units in the plat and shall be collected prior to building permit issuance. To be addressed during final plat. School Walkways 21. A pedestrian access easement between 158'h Place SE and 160th Avenue SE shall be provided over either Tract Hor L (as shown in Exhibit 62). The easement shall have a minimum I 0-foot width and be improved with a 5-foot wide paved surface. A pedestrian access easement will be provided through Tract L & H See sheet Cl.OJ for location. 22. The Applicant, individually or in conjunction with other developers, shall construct an off-site walkway to Liberty High school from the site. The walkway shall be constructed within the right-of-way from 160th Ave SE, east along SE 135th Street to 166th Ave SE, and south to Liberty High School at SE 136th Street, or via alternative right-of-way and easements that become available and are approved by DOES. One acceptable alternative would be to use future right-of-way of Southeast 136th Street and 162nd Avenue Southeast to connect with the sidewalk improvement of "five lot subdivision," and through the plat of"five lot subdivision"/LOOP0023 to the southwest gate of Liberty High School. The walkway shall be designed and constructed in accordance with the 1993 King County Road Standards and shown on the engineering plans for DOES review and approval. Any surfacing alternative from the King County Road Standards (KCRS 3.09) may be submitted for approval through a road variance application. Off-site walkway is currently being constructed by others. ,, ® King County Department of Development and Environmental Services 900 Oakesdale Avenue SW Renton, WA 98055-1219 October 17, 2002 Mike Romano Centurion Development Services 22617 Eighth Drive SE Bothell, WA 98021 Edward J, McCarthy, P.E. Haozous Engineering, P.S. 14816 SE 1161h Street Renton, WA 98059 RE: Evendell Subdivision SWM Adjustment Request (File No. L02V0024) Dear Applicant and Engineer: The Land Use Services Division, Engineering Review Section, has completed review of the adjustment request for the Evendell subdivision. You are requesting approval for an adjustment from the 1998 King County Surface Water Design Manual (KCSWDM) Core Requirement No. 1, Section 1.2.1, Discharge at the Natural Location. Our review of the information and a site visit provides the following findings: 1. The prorosed Evendell subdivision is located west of 1601h Avenue SE and south of SE 1361 Street. The 7 5 lot, 11. 7 acre, proposed E~dell subdivision is filed under Land Use Services Division (LUSD) file number l1P0016. 2. The Evendell subdivision is located in the Orting Hills subbasin of the Lower Cedar River basin. The site is subject to the Level Two flow control and Basic water quality requirements of the 1998 KCSWDM. 3. The site consists of two adjoining, rectangular areas south of SE 1361h Street split by 1581h Avenue SE. The smaller, western rectangle is 1.9 acres in size, while the larger, eastern rectangle is 9 .8 acres. A common ridgeline passes approximately north- northwest to south-southeast through the two areas with the majority of the site draining to the east. The western subbasin sheetflows in a southwest direction through large, single family f arcels and is eventually intercepted by a ditch drainage system on the east side of 1561 A venue SE and flows south. The eastern subbasin sheetflows to the southeast and is eventually intercepted by a ditch system on the west side of 160th A venue SE and flows south. Both downstream drainage paths eventually recombine in an unclassified tributary of the Lower Cedar River. Most upstream flow is intercepted by ditches on the north side of SE 136th Street and is bypassed around the project site or through the wetland area in the northeast comer of the site. 'il • • ", 0 ~ l : 0 • , ; • ~ :j. • 0 N g N ;;, "' ~ 0 i ..,. 0 ' "i . 0 .. E ~ ' C ~ " i ~ a • • ,.._ a;: \_ \ \ 1 \ M~t 'devwest'-i-_ 'deveast' \ I \ ·~~~t ~ L / _...,,\~'---=~~--------==-·__jj, --==-~ .,L./ I <O ..;---- 93ll' 623 JO'W X'loo'L X 7.5'9 (INSIOE ~ 10P OF VNJLT• -482.& WA1IR SURFACE• -481.0 ear. DET.• 475.0 REQ'O OET. VOL~ 18,000 CF r· DET. VOL• 20.200 CF (6.73'0) :;r t,lfflW w.tJtB m war YNttf 10'W X JO'L X &.5'0 (lNS1llE DIM.) · lOP OF VNJlT• 48U WATER SURfACE= 482.0 N88d!4 3811 !306 DET. VOL• 1,500 CF . ~ ear. DET.• •n.o ---=-·-· S?}}j!J.ea4t _ _J._36th SMe~ ~CF~: --~ ==---::,.... --. • • . . -~. • • _3 ·_-. -,:. I WEF!AND & B~ 79\ AC \\ ""'\ Y"".\ \- o~ " ~ I] 0.58 />C DIVERiED L_ FROM EAST TO WEST I I __ __,,-~ --:'<l,l>?I ,seS-~. 56 / 75 j 1/i 73 __J L I I I :______=:---I J I I I L_l_l_j ~ 0.73 J DIVERTED FROM WEST TO EAST lot 7 Rose ' I I .v -,c--.--/-/; J_,,_ __ _ 57 y--t-/--1-"' 72 -~-. ..J / ( --1---- I /.>9~7 I · 58 _ I · _ 71 ---L-ISlTE. l'~-/-----,z. ·.a.e-r --- ! 61/60 j 69 j) .68 ~-: . I / \------_" :J' ,:-t-i-_r 63 I 64 j 65 ~ 66 . ----· ----~=-~ u ~ \ - ~,-=:::: I . ,-+ I i ~<O ::a j I~% IL -~j ::i ! « IL wD ~ ~z 0 z <lit C, :z 1i IP.i ~ i ai=;O Id " ~ 1,; ~ ~ 'r;,· e;o o» ~· • = ,. ~ ~ ..... -.., ti§~ ~ S- Q) ~i:!18 ~ .s ;!;5~~ ~151;.(r---F--lj r-1 :18~ l ; ";.; ~Ii 0 ~ .... 0 N c,j ;,; ti:: - ~ lj! l'l,fS & §.,. 0 2 ' ........ '-~ \._./ Evendell/L02V0024 October 17, 2002 Page 2 of3 4. The proposal is to collect most runoff from the project site and direct it to two facilities designed to separately accommodate drainage from the western and eastern areas of the site. The result is that 0.58 acres of the eastern subbasin will be diverted to the flow control vault and bioswale of the western rectangle of the site; and 0.73 acres of the western subbasin will be diverted to the combined wetpond/detention pond serving the eastern rectangle of the site. In the developed condition, the net effect is that 0.15 acres of the western subbasin will become tributary to the eastern subbasin's downstream drainage system. As a result, controlled outflows from the western area will be released farther upstream in the ditch system of 1561h Avenue SE reducing nuisance sheetflow through the intervening parcels. The release location from the eastern subbas.in will remain the same. A negligible shift in flows in the two downstream drainage paths will result. The current conceptual drainage plan indicates that a significant amount of frontage improvement drainage will bypass the planned RID facilities. 5. No decorative ponds or shallow wells have been identified that would be affected by the proposed diversion. 6. The Level One and Three Downstream Drainage Analyses identified conveyance restrictions and nuisance flooding problems associated with both of the proposed downstream discharge locations. Although this adjustment is not addressing the potential for increased flow control standards as a result of the downstream drainage problems, the net impact of the proposed diversion will have a negligible impact on either downstream drainage path. Based on these findings, we hereby approve this adjustment to allow the diversion of on-site runoff between the two drainage subbasins to two separate facilities ultimately draining to their natural discharge locations with the following conditions: 1. The release rates for the detention facilities will be based on the natural and diverted tributary areas being directed to the facilities. 2. The volume for the detention facility will be basect'on all flows directed to the facilities at full development under current zoning. The allowed release rates will be reduced by any tindetained flows that would bypass the proposed subdivision drainage facilities. A IO to 20 percent volumetric factor of safety must be applied to all storm events requiring detention. The design Technical Information Report shall state the factor of safety selected and the basis of that determination. 3 .. Water quality facilities must be sized based on the entire proposed subdivision draining to the facilities including any required frontage improvements. 4. All onsite or offsite drainage facilities must be located in a public right-of-way or storm drainage tract dedicated to King County. Evendell/L02V0024 October 17, 2002 Page 3 of3 5. Additional storm drainage requirements identified by SEPA or the plat hearing review wiJl apply to this project. · If you have any further questions regarding this KCSWDM adjustment or the design requirements, please contact Mark Bergam at (206) 296-7270. Sincerely, James Sanders, P.E. Development Engineer Engineering Review Section Land Use Services Division · Jim Chan, P.E. Supervising Engineer Site Engineering and Planning Section Building Services Division cc: Curt Crawford, P.E., Managing Engineer, Stormwater Services, KCDNR Randall Parsons, P.E., Senior Engineer, Engineering Review Section, LUSD Bruce Whittaker, Senior Engineer, Engineering Review Section, LUSD Karen Scharer, Planner II, Current Planning Section, LUSD Mark Bergam, P .E., Senior Engineer, Engineering Review Section, LUSD King County Department of Development And Environmental Services 900 Oakesdale A veuue SW Renton, WA 98055-1219 Project Name: Evendell Plat Project Address: Portions of Sections 25 36 ofT23N R5E Appricant: Mr. Mike Romano Address: Centurion Development Services 22617 8th Drive SE · Bothell WA 98021 Phone: ' ( 425) 486-2563" Date: -*c:hz_ DOES File No. LOIP0016 DOES Engineer/Planned Name: Bruce Whittaker P.E. Design Engineer (submitting variance): Edward J. McCarth P.E. Signature: tJwar-d D· f(/cCart~ Engineering Firm Name: Haozous Engineering, P.S. Address: 14816 S.E. I 16th Street Renton, WA 98059 Phone: 425 235:2707 Date: 2/25/02 DESCRIPTION OF THE VARIANCE REQUEST: !_Standard Request We request that the design of the storm water facility that manages storm water from developed portions ofEvendell be allowed to divert drainage from a net area of0.15 acre from the west basin to the east basin on the site. APPLICABLE SECTION($) OF STANDARDS: The adjustment request is applicable to Core Requirement# 1: Discharge at the Natural Location, Section 1.2.1 of the Surface Water Design Manual (King County Department of Natural Resources, 1998). 1'-J4 JUSTIFICATION (see ORO-page attachment): AUTHORIZED SIGNATURES: DDES Dlreetor/Deslgnee Determination: _ Approval CDNDITIDNS OF APPROVAL: I'. See attached memo dated: lb/vt{o,-.. _Denial Date: i,o/11-/ fr'?--, ODES, Land Use Services DMsion, Engineering Review Supervisor: ODES, Bldg. Serv. Div., Site Engineering & Planning Supervisor: Date: Signed: MAR2}!0;@ K.C. D.D.E.S. King Comly Depllrtment of Development And Envirorunental Services 900 Oakesdale Avenue SW Renton, WA 98055·1219 Even dell -Diversion of Drainage -Adjustment Request JUSTIFICATION: Description of Site The Evendell Plat project is a proposed residential development located within the Renton Highlands area of unincorporated King County. The proposal for development includes building 75 single-family dwellings on approximately 12 acres. Road improvements along SE 1361h Street are also proposed. The site is located within the Orting Hills subbasin of the Cedar River watershed (King County Department ofNatural Resources, 1999). The site and area of offsite improvements consist of two basins. The east basin consists of 9. 84 acres under existing conditions. The topography of the east basin generally slopes from the northwest to the southeast. The west basin consists of 1. 92 acres under existing conditions. The topography of the west basin generally slopes from the east to the west. The southwest comer of the site has an area of 0. 73 acre that is included in the westerly subbasin. Runoff from this subbasin sheet flows to adjacent yards of single-family residences to the southwest. Stormwater Design Under developed conditions, stormwater from the site and off site road improvements will be collected and treated onsite to basic water quality standards. A combined wetpond/detention pond will be used to manage runoff in the easterly basin. A vault followed by a biofiltration swale will be used to manage runoff in the westerly basin. Level 2 RID standards are required by the King County Flow Application Maps and are recommended by Lower Cedar River Basin and Nonpoint Action Plan. Under developed conditions, the 0.73-acre area in the southwest comer of the site will be diverted from the westerly basin and collected in the onsi_te stormwater system in the. easterly basin. To compensate for this diversion of drainage, an area of0.58 acre in the northwest portion of the site will be diverted from the east basin to the west. The net result will be a diversion of 0.15 acre from the west basin to the east basin. Managing runoff with the proposed diversions results in the following features: 0 Two stormwater facilities will be constructed. A larger combined wetpond/detention pond will manage runoff in the easterly basin and will discharge to the ditch system along 1601h Avenue SE. Avault will be used ' to manage runoff from the smaller westerly basin and will discharge to the ditch system along 1561h Avenue SE. • The discharge locations from each basin will be to an engineered conveyance system. • The net diversion of0.15 acre is not anticipated to cause any problems in either of the two basins. References King County Department of Parks, Planning, and Resources, 1990. Sensitive Areas Map Folio. King County Environmental Division, 1990. Wetlands Inventory Notebook Volume 2 East. King County Department ofNatural Resources, 1998. Surface Water Design Manual. King County Surface Water Management Division, 1993a. Cedar River Current and Future Conditions Report. 1 CORE -Dave Cayton oin: ..,ent: · To: Subject: Kurt Wilson [kurt@soundbuilthomes.com] Thursday, April 29, 2004 2:48 PM CORE -Dave Cayton FW: Evendell Fire Access Requirement (Tract H) FYI-please work this out with KC fire for approval. Lets propose the cable or chain for now. Kurt Wilson SBI Developing, LLC Office: (253) 539-8116 Fax: (253) 539-0514 cell: (253) 377-7147 cc;<;·;;: ,,.,,,,_..,.~"··,·,-: c~c--Original Message----- c/iriJ.'fi( Corey W Thomas [mailto:CThomas@ci.renton.wa.us] ~fi\(Thursday, April 29, 2004 11 :38 AM To: Kurt Wilson Subject: Re: Evendell Fire Access Requirement (Tract H) 'ie Renton Fire Department will accept chain or cable type gating ~ystems as Jong as the posts supporting them are fully clear of the 20,feet width when the chain or cable is unlocked. We will not accept bollards. The distance of 50-feet may be measured from the drive lane rather than the right of way. '~,:•I. >>> "Kurt Wilson" <kurt@soundbuilthomes.com> 04/28/2004 11 :55:27 >>> Perc.ondition # 6 we are required to provide a Jocking device which can n"ofbt, 'a cable or chain, per our discussion you would allow this so long . I . . . a~;)V,fllid not propose bollards. Can you affirm this in a response back t~1.ttrn?·'.".Also, is there any possibility in locating the cable 50ft from v .. ,.", ' ( tbe!tlriviilg lane on 160th rather than 50ft from the ROW? It would ~~~ilyhelp our access to the lot closest to 160th.: 6. The Applicant must obtain the approval from the King County Fire Protection Engineer for the adequacy of the fire hydrant, water main, and fire flow standards of Chapter 17.08 of the I<.in'g County Code. <?xml:namespace prefix = o ns = "uril:schemas-microsoft-com:office:office" /> c\irti Use Development Tract H as shown on the plat will provide access _,;!.,~.ts 28 and 29. Additionally, it is a future emergency vehicle a'c{~~s tract to and from 160th Avenue SE, which the Applicant propose::s t~cr,1~tfin response to concerns raised by the City of Renton. The ~pplic:'ant shall include proposed protocols for the construction and t~C·t~;·:~ · 1 ~ .. .maintenance.of Tract H, plus any related plat notes, with its : engineering plans submittal, meeting the following standards: . The emergency vehicle access to 160th Avenue SE shall have a minimum driving surface width of20 feet, with an all-weather surface capable of ,supporting 25 tons. Any locking device shall be approved by the Renton ;Wfe Department (KCFD # 25). Chains, cable or bollards will not be i,i?~tin,i)ted. The gate shall be located at least 50_ feet fro?1160th Avenue S.Eto allow space for fire apparatus to stop while opemng the gate or 1.t,{0Jit'before entering the public roadway. If these conditions are not ',ri{~laAy future residence constructed on Lots 28 and 29 will have to be sprinklered NFP A 13D. These requirements concerning adequate fire and emergency access may be modified in a manner approved by the King County Fire Protection Engineer and King County Fire District no. 25. Thanks for your consideration> ,J(ifrt Wilson · ~~I D.eveloping 3~539-8116 office 23:,!5~9-0514 fax is:f1'h-7147 cell . ,, . ._. ' . . This message has been scanned by the City ofRenton's filtering gateway. 2 CHICAGO TITLE INSURANCE COMPANY 701 FIFfH AVENUE, #3400, SEATTLE, WA 98104 A.L.T.A. COMMITMENT SCHEDULE A Title Unit: U-06 Phone: (206)628-5610 Fax: (206)628-9717 THIRD COMMITMENT Order No.: 1077234 Officer: SA VIDIS/W AGNER/CAMPBELL/MINOR Your No.: US LAND/SB! DEVELOPING Commitment Effective Date: MAY 5, 2004 1 . Polley or Policies to be Issued: at 8:00A.M. ALTA Owner's Policy 1992 EXTENDED SUBDIVIDER SALE -EXTENDED RATE Amount: Premium: Tax: $3,124,000.00 $4,158.00 $ 365.90 Proposed Insured: SB I DEVELOP I NG, L. LC. , A WASHINGTON LIM I TEO LI AB IL ITV COMPANY Policy or Policies to be issued: ALT A Loan Policy Proposed Insured: Policy or Policies to be issued: ALT A Loan Policy Proposed Insured: Amount: $0.00 Premium: Tax: Amount: $0. 00 Premium: Tax: 2 . The estate or Interest in the land which Is covered by this Commitment is: FEE SIMPLE 3. Title to the estate or interest in the land is at the effective date hereof vested in: DAVID A. NYBLOM AND DEBRA L. ALBISO, HUSBAND ANO WIFE, AS TD PARCEL A; AND ROBERT A. MAIR ANO CLYOERAE MAIR, HUSBAND AND WIFE, AS TO PARCEL B 4. The land referred to In this Commitment is described as follows: SEE ATTACHED LEGAL DESCRIPTION EXHIBIT WLTACOMA/RDA/0999 PARCEL A: CHICAGO TITLE INSURANCE COMPANY A.LT.A. COMMITMENT SCHEDULE A (Continued) Order No.: 1077234 · Your No.: US LAND/SB I DEVELOPING LEGAL DESCRIPTION EXHIBIT (Paragraph 4 of Schedule A continuation) THE EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH. RANGE 5 EAST, WILLAMETTE MERIDIAN, IN KING COUNTY, WASHINGTON; EXCEPT THAT PORTION OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SAID SECTION 14 DESCRIBED AS FOLLOWS: BEGINNING AT THE SOUTHEAST CORNER OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER AS THE POINT OF TRUE BEGINNING; THENCE NORTH 00'25'21" EAST 523.99 FEET ALONG THE EAST LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE NORTH 88'07'58" WEST 653.61 FEET TO THE WEST LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE SOUTH 0'27'05" WEST 525.82 FEET TO THE SOUTH LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE SOUTH 88'17'35" EAST 653.84 FEET ALONG THE SOUTH LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER TO THE TRUE POINT OF BEGINNING; AND EXCEPT COUNTY ROADS. PARCEL B: THE NORTH HALF OF THE NORTH HALF OF THE NORTHWEST QUARTER OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH, RANGE 5 EAST, WILLAMETTE MERIDIAN, IN KING COUNTY, WASHINGTON; EXCEPT THE WEST 30 FEET CONVEYED TO KING COUNTY FOR ROAD PURPOSES BY DEED RECORDED UNDER RECORDING NUMBER 1094243. TOGETHER WITH A NON-EXCLUSIVE EASEMENT FOR INGRESS, EGRESS AND UTILITIES OVER, UNDER AND ACROSS THE NORTH 15 FEET OF THE WEST 187 FEET (AS MEASURED FROM THE EASTERLY MARGIN OF COUNTY ROAD RIGHT OF WAY) OF LOT 2 OF SHORT PLAT NO. 878133 1 RECORDED UNDER RECORDING NUMBER 8002250639, IN KING COUNTY, W/\SHINGTON; ~\Y'I~ ~~m'T 'Fo"(( c.on\/l::.YIDrnlf. ~ ~T n 1)t.f\-\nAf:it. "Fl4UUT'Y. CLTACMA&/RDA/0999 ) CHICAGO TITLE INSURANCE COMPANY A.LT.A. COMMITMENT SCHEDULEB Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING Schedule B of the policy or policies to be issued will contain exceptions to the following matters unless the same are disposed ofto the satisfaction of the Company. GENERAL EXCEPTIONS A. Rights or claims of parties in possession not shown by the public records. B. Encroachments, overlaps, boundary line disputes, or other matters which would be disclosed by an accurate survey and inspection of the premises. C. Easements, or claims of easements, not shown by the public records. D. Any lien, or right to a lien, for contributions to employee benefit funds, or for state workers' compensation, or for services, labor, or material heretofore or hereafter furnished, all as imposed by law, and not shown by the public records. E. Taxes or special assessments which are not shown as existing liens by the public records. F. Any service, installation, connection, maintenance, tap, capacity or construction charges for sewer, water, electricity, other utilities, or garbage collection and disposal. G. Reservations or exceptions in patents or in Acts authorizing the issuance thereof; Indian tribal codes or regulations, Indian treaty or aboriginal rights, including easements or equitable servitudes. H. Water rights, claims, or title to water. I. Defects, liens, encumbrances, adverse claims or other matters, if any, created, first appearing In the public records, or attaching subsequent to the effective date hereof but prior to the date the proposed Insured acquires of record for value the estate or interest or mortgage thereon covered by this Commitment. SPECIAL EXCEPTIONS FOLLOW WLTACOMB/RDA/0999 CHICAGO TITLE INSURANCE COMP ANY A.L.T.A. COMMITMENT SCHEDULEB (Continued) Order No.: 001077234 Your No.: SPECIAL EXCEPTIONS A 1. EASEMENT AND THE TERMS AND CONDITIONS THEREOF: GRANTEE: PURPOSE: AREA AFFECTED: RECORDED: RECORDING NUMBER: KING COUNTY WATER DISTRICT NUMBER 90, A MUNICIPAL CORPORATION WATER AND SEWER MAINS WITH NECESSARY APPURTENANCES NORTHERLY 30 FEET OF PARCEL B JULY 17, 1975 7507170570 B 2. EASEMENT AND THE TERMS AND CONDITIONS THEREOF: GRANTEE: PURPOSE: AREA AFFECTED: RECORDED: RECORDING NUMBER: PUGET SOUND POWER & LIGHT COMPANY, A WASHINGTON CORPORATION ELECTRIC TRANSMISSION AND/OR DISTRIBUTION LINES A RIGHT OF WAY 10 FEET IN WIDTH HAVING 5 FEET OF SUCH WIDTH ON EACH SIDE OF A CENTERLINE DESCRIBED AS FOLLOWS: THE CENTERLINE OF GRANTEE'S FACILITIES AS CONSTRUCTED OR TO BE CONSTRUCTED, EXTENDED OR RELOCATED, LYING WITHIN PARCEL A FEBRUARY 23, 1995 9502230476 C 3. PAYMENT OF THE REAL ESTATE EXCISE TAX, IF REQUIRED. THE PROPERTY DESCRIBED HEREIN IS SITUATED WITHIN THE BOUNDARIES OF LOCAL TAXING AUTHORITY OF UNINCORPORATED KING COUNTY. PRESENT RATE IS 1.78%. ANY CONVEYANCE DOCUMENT MUST BE ACCOMPANIED BY THE OFFICIAL WASHINGTON STATE EXCISE TAX AFFIDAVIT. THE APPLICABLE EXCISE TAX MUST BE PAID AND THE AFFIDAVIT APPROVED AT THE TIME OF THE RECORDING OF THE CONVEYANCE DOCUMENTS. D 4. GENERAL AND SPECIAL TAXES AND CHARGES, PAYABLE FEBRUARY 15, DELINQUENT IF FIRST HALF UNPAID ON MAY 1, SECOND HALF DELINQUENT IF CLTACMBJ/RDA/0999 CHICAGO TITLE INSURANCE COMPANY A.LT.A. COMMITMENT SCHEDULEB (Continued) Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING SPECIAL EXCEPTIONS UNPAID ON NOVEMBER 1 OF THE TAX YEAR (AMOUNTS DO NOT INCLUDE INTEREST AND PENAL Tl ES) : YEAR: TAX ACCOUNT NUMBER: LEVY CODE: ASSESSED VALUE-LAND: ASSESSED VALUE-IMPROVEMENTS: GENERAL & SPECIAL TAXES: AFFECTS: PARCEL A 2004 142305-9009-04 6870 $ 257,000.00 $ 336,000.00 BILLED: PAID: UNPAID: $ 7,280.03 $ 3,640.02 $ 3,640.01 E 5. GENERAL AND SPECIAL TAXES AND CHARGES, PAYABLE FEBRUARY 15, DELINQUENT IF FIRST HALF UNPAID ON MAY 1, SECOND HALF DELINQUENT IF UNPAID ON NOVEMBER 1 OF THE TAX YEAR (AMOUNTS DO NOT INCLUDE INTEREST AND PENALTIES): YEAR: TAX ACCOUNT NUMBER: LEVY CODE: ASSESSED VALUE-LAND: ASSESSED VALUE-IMPROVEMENTS: GENERAL & SPECIAL TAXES: AFFECTS: PARCEL B 2004 142305-9022-07 4350 $ 95,000.00 $110,000.00 BILLED: PAID: UNPAID: $ 2,635.06 $1,317.53 $1,317.53 F 6. DEED OF TRUST AND THE TERMS AND CONDITIONS THEREOF: GRANTOR: TRUSTEE: BENEFICIARY:. AMOUNT: DAVID A. NYBLOM AND DEBRA L. ALBISO, HUSBAND AND WIFE NORTHWEST FINANCIAL CORPORATION, A WASHINGTON CORPORATION FIRST SAVINGS BANK OF WASHINGTON $ 203,150.00 CLTACMB2/RDA/099t CHICAGO TITLE INSURANCE COMP ANY A.L.T.A. COMMITMENT DATED: RECORDED: RECORDING NUMBER: LOAN NUMBER: SCHEDULEB ( Continued) Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING SPECIAL EXCEPTIONS JULY 21, 1995 AUGUST 1, 1995 9508010201 7 744958 17 THE AMOUNT NOW SECURED BY SAID DEED OF TRUST AND THE TERMS UPON WHICH THE SAME CAN BE DISCHARGED OR ASSUMED SHOULD BE ASCERTAINED FROM THE HOLDER OF THE INDEBTEDNESS SECURED. H AFFECTS: PARCEL A 7. DEED OF TRUST AND THE TERMS AND CONDITIONS THEREOF: GRANTOR: TRUSTEE: BENEFICIARY: AMOUNT: DATED: RECORDED: RECORDING NUMBER: LOAN NUMBER: ROBERT A. MAIR AND CLYDERAE MAIR, HUSBAND AND WIFE FIDELITY MORTGAGE TRUSTEE SERVICE, A CALIFORNIA CORPORATION IMC MORTGAGE COMPANY DBA COREWEST MORTGAGE COMPANY $122,000.00 JULY 18, 1997 JULY 31, 1997 9707311685 3WA-11028 THE AMOUNT NOW SECURED BY SAID DEED OF TRUST AND THE TERMS UPON WHICH THE SAME CAN BE DISCHARGED OR ASSUMED SHOULD BE ASCERTAINED FROM THE HOLDER OF THE INDEBTEDNESS SECURED. J AFFECTS: PARCEL B L 8. DEED OF TRUST AND THE TERMS AND CONDITIONS THEREOF: GRANTOR: TRUSTEE: BENEFICIARY: AMOUNT: DAVID A. NYBLOM AND DEBRA L. ALBISO, HUSBAND AND WIFE CHICAGO TITLE INSURANCE COMPANY KING COUNTY CREDIT UNION $ 98,000.00 CL T ACMBZ/RDA/0999 CHICAGO TITLE INSURANCE COMPANY A.L.T.A. COMMITMENT SCHEDULEB (Continued) Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING DATED: RECORDED: RECORDING NUMBER: LOAN NUMBER: SPECIAL EXCEPTIONS SEPTEMBER 17, 2001 SEPTEMBER 24, 2001 20010924002679 NOT DISCLOSED THE AMOUNT NOW SECURED BY SAID DEED OF TRUST AND THE TERMS UPON WHICH THE SAME CAN BE DISCHARGED OR ASSUMED SHOULD BE ASCERTAINED FROM THE HOLDER OF THE INDEBTEDNESS SECURED. AFFECTS: PARCEL A Z 9. MATTERS DISCLOSED BY SURVEY RECORDED UNDER RECORDING NUMBER 9508099008, AS FOLLOWS: A. BARN APPURTENANT TO PARCEL A ENCROACHES UP TO 1.0 FEET INTO SOUTHERLY ADJOINER; B. FENCES NEAR WESTERLY AND SOUTHERLY PROPERTY BOUNDARIES OF PARCEL A DO NOT CONFORM WITH PROPERTY LINES. N 10. A PORTION OF THE IMPROVEMENTS LOCATED ON THE HEREIN DESCRIBED PROPERTY WAS PREVIOUSLY A MOBILE HOME WHICH HAS BEEN CONVERTED TO REAL PROPERTY BY MANUFACTURED HOME TITLE ELIMINATION CERTIFICATE RECORDED UNDER RECORDING NUMBER 20010919001892. D AFFECTS: PARCEL B P 11. RIGHT, TITLE AND INTEREST OF U.S. LAND DEVELOPMENT ASSOCIATES, A WASHINGTON GENERAL PARTNERSHIP, PRESUMED BY THE APPLICATION FOR TITLE INSURANCE TO HAVE AN INTEREST IN SAID PREMISES. Q NOTE: SAID INTEREST, IF ANY, IS SUBJECT TO THE FOLLOWING MATTERS SHOWN AT PARAGRAPHS 12 AND 13. R 12. TERMS AND CONDITIONS OF THE PARTNERSHIP AGREEMENT FOR U.S. LAND DEVELOPMENT ASSOCIATES. S NOTE: A COPY OF THE PARTNERSHIP AGREEMENT, AND AMENDMENTS THERETO, IF ANY, MUST BE SUBMITTED. CLTACMBZ/RDA/0999 CHICAGO TITLE INSURANCE COMPANY A.LT.A. COMMITMENT SCHEDULEB (Continued) Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING SPECIAL EXCEPTIONS T 13. ANY CONVEYANCE OR MORTGAGE BY U.S. LAND DEVELOPMENT ASSOCIATES, MUST BE EXECUTED IN ACCORDANCE WITH THE PARTNERSHIP AGREEMENT AND BY ALL THE GENERAL PARTNERS AND THEIR RESPECTIVE SPOUSES AS OF THE DATE OF ACQUISITION, OR EVIDENCE MUST BE SUBMITTED THAT CERTAIN DESIGNATED PARTNERS HAVE BEEN AUTHORIZED TO ACT FOR THE PARTNERSHIP. AK 14. PHYS I CAL INSPECTION MADE MARCH 4, 2003 VERIFIED THE REQUIREMENT FOR A SURVEY DUE TO LACK OF ACCESS TO SITE AND OVERALL SIZE OF PROPERTY. V 15. PRIOR TO ISSUING AN EXTENDED FORM OWNER'S POLICY THIS COMPANY REQUIRES THAT THE PARTIES TO THE TRANSACTION PROVIDE AN ALTA/ASCM CERTIFIED, AS-BUILT SURVEY. AD 16. THE LEGAL DESCRIPTION IN THIS COMMITMENT IS BASED ON INFORMATION PROVIDED WITH THE APPLICATION AND THE PUBLIC RECORDS AS DEFINED IN THE POLICY TO ISSUE. THE PARTIES TO THE FORTHCOMING TRANSACTION MUST NOTIFY THE TITLE INSURANCE COMPANY PRIOR TO CLOSING IF THE DESCRIPTION DOES NOT CONFORM TO THEIR EXPECTATIONS. AF 17. IT IS OUR UNDERSTANDING THAT THE INTENDED TRANSACTION INVOLVES THE SUBDIVISION OF PARCEL B BY MEANS OF A LOT LINE ADJUSTMENT. UPON THE SUBMISSION AND REVIEW OF THE FINAL LEGAL DESCRIPTION OF THE PROPERTY TO BE CONVEYED, THIS COMMITMENT WILL BE REVISED ACCORDINGLY. AE THE PREMIUM FOR THE FORTHCOMING OWNER'S POLICY IS COMPUTED AS FOLLOWS: STANDARD COVERAGE - EXTENDED SURCHARGE - INSPECTION FEE - AL NOTE 1: $ 2,138.00 PLUS TAX OF$ 188.14 $1,870.00 PLUS TAX OF$ 164.56 $ 150.00 PLUS TAX OF$ 13.20 IN THE EVENT THE OWNER'S POLICY COVERAGE IS CHANGED FROM EXTENDED TO STANDARD COVERAGE A CHARGE OF $150.00, PLUS $13.20 SALES TAX, WILL BE ADDED TO COVER THE COSTS RELATING TO THE EXTENDED COVERAGE INSPECTION. AA NOTE 2: EFFECTIVE JANUARY 1, 1997, DOCUMENT FORMAT AND CONTENT REQUIREMENTS HAVE BEEN IMPOSED BY WASHINGTON LAW. FAILURE TO COMPLY WITH THE FOLLOWING REQUIREMENTS MAY RESULT IN REJECTION OF THE DOCUMENT BY THE CLTACMB2/RDA/0999 ) CHICAGO TITLE INSURANCE COMP ANY A.LT.A. COMMITMENT SCHEDULEB (Continued) Order No.: 1077234 Your No.: US LAND/SB I DEVELOPING SPECIAL EXCEPTIONS COUNTY RECORDER OR IMPOSITION OF A $50.00 SURCHARGE. FIRST PAGE OR COVER SHEET REQUIREMENTS: 3" TOP MARGIN CONTAINING NOTHING EXCEPT THE RETURN ADDRESS. 1" SIDE AND BOTTOM MARGINS CONTAINING NO MARKINGS OR SEALS. TITLE($) OF DOCUMENTS. RECORDING NO. OF ANY ASSIGNED, RELEASED OR REFERENCED DOCUMENT(S). GRANTORS NAMES (AND PAGE NO. WHERE ADDITIONAL NAMES CAN BE FOUND). GRANTEES NAMES (AND PAGE NO. WHERE ADDITIONAL NAMES CAN BE FOUND). ABBREVIATED LEGAL DESCRIPTION (AND PAGE NO. FOR FULL DESCRIPTION). ASSESSOR'S TAX PARCEL NUMBER(S). RETURN ADDRESS (IN TOP 3" MARGIN). **A COVER SHEET CAN BE ATTACHED CONTAINING THE ABOVE FORMAT AND DATA IF THE FIRST PAGE DOES NOT CONTAIN ALL REQUIRED DATA. ADDITIONAL PAGES: 1" TOP, SIDE AND BOTTOM MARGINS CONTAINING NO MARKINGS OR SEALS. ALL PAGES: NO STAPLED OR TAPED ATTACHMENTS. EACH ATTACHMENT MUST BE A SEPARATE PAGE. ALL NOTARY AND OTHER PRESSURE SEALS MUST BE SMUDGED FOR VISIBILITY. FONT SIZE OF B POINTS OR LARGER. ALL INFORMATION MUST BE LEGIBLE AND CAPABLE OF BEING IMAGED. THE FOLLOWING MAY BE USED AS AN ABBREVIATED LEGAL DESCRIPTION ON THE DOCUMENTS TO BE RECORDED TO COMPLY WITH THE REQUIREMENTS OF RCW 65.04. SAID ABBREVIATED LEGAL DESCRIPTION IS NOT A SUBSTITUTE FOR A COMPLETE LEGAL DESCRIPTION WHICH MUST ALSO APPEAR IN THE BODY OF THE DOCUMENT: POR OF NW 1/4 OF SE 1/4 OF SEC 14, TWP 23 N, RGE 5 E, W.M. END OF SCHEDULE B CLTACMBZ1RDA/09!l9 CHICAGO TITLE INSURANCE COMPANY A.LT.A. COMMITMENT SCHEDULEB (Continued) Order No.: 1077234 Your No.: US LJ\ND/SBI DEVELOPING SPECIAL EXCEPTIONS AC THE FOLLOWING PARTIES HAVE BEEN SENT A COPY OF THIS COMMITMENT: CTI/SCOTT SMOUSE SCOTT SMOUSE HOWARD STANSBURY MICHAEL UTT SBI DEVELOPING, L.L.C. 1/1 KURT WILSON 1 /1 CLTACMBZ/RDA/0999 3. OFFSITE ANALYSIS: A Level I and Level 3 Offsite Drainage Analyze were completed by Haozous Engineering during preliminary engineering. A copy of the report is attached in Section 6 of this report. Upstream Tributary Area Drainage from the area north of SE 1361h Street, that would otherwise enter the property, is cut off by an existing ditch that runs along the north side of SE 136 1h Street. Proposed development will either preserved the existing ditch or a rockery and/or perforated pipe will be installed behind the rockery or the proposed back of curb to direct the upstream drainage into the existing ditch or downstream to 1561h Avenue SE conveyance system. The existing ditch that runs along the north side of SE 1361h Street naturally drains to an existing ditch that runs south along the west side of l 60'h Avenue SE. Proposed improvements to SE 136 1h Street will include the installation of a culvert that crosses under SE 1361h Street and directs the upstream drainage to a proposed ditch that will be located approximately 8' west of the existing ditch that runs along 1601h Avenue NE due to proposed shoulder construction along l 60'h Avenue SE. This upstream drainage will bypass proposed detention/water quality facilities. The East Basin receives approximately 0.36 acres of upstream drainage from forested land. See Existing and Developed Conditions Exhibit in Section 4 of this report. This area will be routed through the proposed East Basin wetpond. Downstream Analysis A Level 1 and Level 3 Offsite Drainage Analyze were completed by Haozous Engineering during preliminary engineering. A copy of the report is attached in Section 6 of this report. 7. Final plat approval shall require full compliance with the drainage provisions set forth in King County Code 9.04. Compliance may result in reducing the number and/or location of lots as shown on the preliminary approved plat. Preliminary review has identified the following conditions of approval which represent portions of the drainage requirements. All other applicable requirements in KCC 9.04 and the Surface Water Design Manual (SWDM) must also be satisfied during engineering and final review. a. Drainage plans and analysis shall comply with the 1998 King County Surface Water Design Manual and applicable updates adopted by King County. DDES approval of the drainage and roadway plans is required prior to any construction. Drainage facilities and analysis comply with the 1998 KCSWDM. See sheets C4.0l, C4.21, C4.22, C4.31, C4.32, C4.33 o the civil plan set for storm drainage design and T.J.R. for storm drainage analysis. b. Current standard plan notes and ESC notes, as established by DDES Engineering Review, shall be shown on the engineering plans. Plan notes are no sheets CUJ2, C2.0l, CJ.31, and C4.33 of the civil plan set. c. The following note shall be shown on the final recorded plat: "All building downspouts, footing drains, and drains from all impervious surfaces such as patios and driveways shall be connected to the permanent storm drain outlet as shown on the approved construction drawings# on file with DDES and/or the King County Department of Transportation. This plan shall be submitted with the application of any building permit. All connections of the drains must be constructed and approved prior to the final building inspection approval. For those lots that are designated for individual lot infiltration systems, the systems shall be constructed at the time of the building permit and shall comply with plans on file." To be address during final plat. d. The stormwater detention design shall comply with the Level 2 or Level 3 Flow Control requirements, as applicable, per the 1998 King County Surface Water Design Manual (KCSWDM). (See SEPA conditions in condition no. 19.) The West Basin drainage facility was sized using Level 3 Flow Control. The East Basin drainage facility was sized using Level 2 Flow Control. See T.I.R. for detention analysis. e. The storm water control facility shall be located in a separate tract and dedicated to King County unless portions of the drainage tract are used for required recreation space in accordance with KCC 2\A.14.180. The wetvault for the West Basin is located in a separate tract labeled "Tract N". The wetpondfor the East Basin is located in a separate tract labeled "Tract M". These tracts will be dedicated to King County during final plat. ) 4. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN: A. Hydraulic Analysis The drainage analysis was modeled using the King County Runoff Time Series software. The onsite soils are Alderwood (AgC), KCRTS group Till per the Soils Map attached on the following pages. The site is located in the Sea-Tac rainfall region with a location scale factor of 1.0. EXISTING CONDITIONS TRADING OF EXISTING IMPERVIOUS PAVEMENT FOR PROPOSED IMPERVIOUS AREA BYPASSING DETENTION/WATER QUALITY FACILITIES Areas ofroad improvements along SE 1361h Street and shoulder addition along 1601h Avenue SE will be bypassing the proposed storm drainage facilities. As a trade off, existing asphalt areas equal to or more than the bypass areas will be collected and treated within the proposed storm drainage facilities. The existing asphalt areas will be considered pasture in the existing condition and impervious in the proposed condition. Since these existing impervious surfaces were not treated and/or detained for in the past, the total runoff from the bypass areas plus the outflows from the detention/water quality facilities will be the same or less than the outflows as they exist today. See Existing and Developed Conditions Exhibit on the following pages for delineation of the existing impervious areas to be collected and proposed pavement areas to be bypassed. WEST BASIN The basin boundary delineated for the West Basin includes the development and SE 1361h Street west of the existing basin ridge. A portion of the most western portion of SE 1361h Street will not be included in the existing condition, i.e. not captured in the proposed drainage system, since an equal amount of existing asphalt will be included within the developed West Basin and treated as pasture in the existing condition. For the reasons stated above, detention does not need to account for the bypass area since existing asphalt will be treated in the place of the bypass impervious surfaces. The western portion of the site is 1.81 acres. The existing coverage is a combination of impervious surfaces associated with the existing outbuildings, pasture, landscaping, lawn, and forest. The existing landscaping and lawn will be considered pasture per Table 3.2.2.C in the 1998 KCSWDM for existing developed areas with densities less than 4 DU/ AC. The site is covered with 1.57 acres of pasture and 0.20 acre of forest. Existing impervious surfaces from the existing outbuildings cover a total area of0.04 acre. Per Table 3.2.2.E in the 1998 KCSWDM, the effective impervious fraction for the site is 0.40 for existing rural areas. The effective impervious area is therefore 0.40*0.04 acre = 0.02 acre. Pasture will be utilized for the non-effective impervious surfaces (0.04 acre -0.02 acre= 0.02 acre). The following information was used for generating time series and flow frequencies. WEST BASIN Total Area= 1.81 acres EXISTING CONDITIONS (exwest) GROUND COVER AREA(acre) Till-Forest 0.20 Till-Pasture (1.57 + 0.02) 1.59 Imoervious 0.02 . ,• -· . .. .. . ..... J. •• •• .. ,' I s:if AGRICULTURE t KING COUNT?N SERVICE II ' ... • ' : , ..• -. A,JC . . . . . : .. : : _ ...... -.:J ,· . . . . - (RENT .- Eve ' II " " .. ~ . "· •\\. \\",. , .. •sc .·· . , •" I • • • .. .. . .. ..... . . . . . . . . :. ..... . : .. : ":; ... : : :" . ··,·.;.,\/(.~~~ • • "••" . I II 1: ~:f " II• • i( ABC • .... 1 • • II I " II " " " . " ._:._ ____ _ II .. ~,~"'='i5f1'ri '-=:i.,,-:-'11, .. .. ,: KING COUNTY ~OIL SURVEY EVENDELL ! CORE PROJECT NO. 04009 · ) --->;,> 3.2.2 KCRTS/RUNOFFFILES METHOD-GENERATING TIME SERIES SCS Soil Type scs KCRTS Soil Notes Hydrologlc Group Soil Group -Alderwood (AgB, Age, AgD) e I Till J Arents, Alderwood Material (AmB, Ame) e Till Arents, Everett Material (An) B Outwash 1 Beausite (Bee, BeD, BeF) e Till 2 Bellingham (Bh) D Till 3 Brisco! (Br) D Till 3 Buckley (Bu) D Till 4 Earlmont (Ea) D Till 3 Edgewick (Ed) e Till 3 Everett (EvB, Eve, EvD, Ewe) NB Outwash 1 Indianola (lne, lnA, lnD) A Outwash 1 Kitsap (KoB, Kpe, KpD) e Till Klaus /Kse) e Outwash 1 Naillon (Nee) A Outwash 1 Newberg (Ng) B Till 3 Nooksack (Nk) e Till 3 Norma (No) D Till 3 Orcas (Or) D Wetland Oridia (Os) D Till 3 Ovall (Ove, OvD, OvF) e Till 2 Pilchuck (Pc) e Till 3 Puget (Pu) D Till 3 Puyallup (Py) B Till 3 Ragnar (Rae, RaD, Rae, RaE) B Outwash 1 Renton (Re) D Till 3 Salal (Sa) e Till 3 Sammamish (Sh) D Till 3 Seattle (Sk) D Wetland Shalcar (Sm) D Till 3 Si (Sn) e Till 3 Snohomish (So, Sr) D Till 3 Sultan (Su) C Till 3 Tukwila (Tu) D Till 3 Woodinville (Wo) D Till 3 Notes: 1. Where outwash soils are saturated or underlain at shallow depth {<5 feet) by glacial till, they should be treated as till soils. 2. These are bedrock soils, but calibration of HSPF by King County DNR shows bedrock soils to have similar hydrologic response to till soils. 3. These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water table. In the absence of detailed study, these soils should be treated as till soils. 4. Buckley soils are formed on the low-permeability Osceola mudflow. Hydrologic response is assumed to be similar to that of till soils. 1998 Surface Water Design Manual 9/1/98 3-25 ST 1.1 ST 1.0 Rainfall Regions and Regional Scale Factors vn Incorporated Area -...= River/Lake Major Road LA 0.9 LA 1.2 EAST BASIN The basin boundary delineated for the East Basin includes the development, SE 1361h Street east of the existing basin ridge, and a portion of 1601h Avenue SE. A portion of the shoulder additional along 1601h Avenue SE will not be included in the existing condition, i.e. not captured in the proposed drainage system, since an equal amount of existing asphalt will be included within the existing/developed East Basin and treated as pasture in the existing condition. For the reasons stated above, detention does not need to account for the bypass area since existing asphalt will be treated in the place of the bypass impervious surfaces. The eastern portion of the site is I 0.06 acres. The existing coverage is a combination of impervious surfaces associated with the existing residence, pasture, landscaping, lawn, and forest. The existing landscaping and lawn will be considered pasture per Table 3.2.2.C in the 1998 KCSWDM for existing developed areas with densities less than 4 DU/AC. The site is covered with 3.00 acres of pasture and 6.62 acres of forest. Existing impervious surfaces from the existing residence and outbuildings cover a total area of 0.44 acre. Per Table 3.2.2.E in the 1998 KCSWDM, the effective impervious fraction for the site is 0.40 for existing rural areas. The effective impervious area is therefore 0.40*0.44 acre= 0.18 acre. Pasture will be utilized for the non-effective impervious surfaces (0.44 acre -0.18 acre= 0.26 acre). The following information was used for generating time series and flow frequencies. EAST BASIN Total Area= 10.06 acres ~:XISTING CONDITIONS (ex east) GROUND COVER AREA/acre) Till-Forest 6.62 Till-Pasture (3.00 + 0.26) 3.26 Imnervious 0.18 TRIBUTARY AREA CONDITIONS EAST BASIN The East Basin receives 0.36 acre of upstream drainage from forest area just west of the site. The following information was used for generating time series and flow frequencies. EAST UPSTREAM Total Area= 0.36 acre TRIBUTARY CONDITIONS (uosteast) GROUND COVER AREA(acre) Till-Forest 0.36 Flow Frequency Analysis Time Series File:exwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks Rank Return Prob (CFS) (CFS) Period 0.128 2 2/09/01 18:00 0 .216 1 100.00 0.990 0.049 7 1/05/02 16:00 0.128 2 25.00 0. 960 0 .116 3 2/28/03 3:00 0.116 3 10.00 0.900 0.014 8 3/24/04 19:00 0.109 4 5.00 0.800 0.066 6 1/05/05 8:00 0.105 5 3.00 0.667 0.109 4 1/18/06 16:00 0.066 6 2.00 0.500 0.105 5 11/24/06 4:00 0. 049 7 1. 30 0.231 0.216 1 1/09/08 6:00 0. 014 8 1.10 0.091 Computed Peaks 0.187 50.00 0.980 Flow Frequency Analysis Time Series File:preeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks Rank Return Prob (CFS) (CFS) Period 0.698 2 2/09/01 18:00 0.999 1 100.00 0.990 0.238 7 1/05/02 16:00 0.698 2 25.00 0. 960 0.580 3 2/28/03 3:00 0.580 3 10.00 0.900 0.060 8 8/26/04 2:00 0.559 4 5.00 0.800 0.339 6 1/05/05 8:00 0.516 5 3.00 0.667 0.559 4 1/18/06 20:00 0.339 6 2.00 0.500 0.516 5 11/24/06 4:00 0.238 7 1. 30 0.231 0.999 1 1/09/08 9:00 0.060 8 1.10 0.091 Computed Peaks 0.899 SO.OD 0.980 Flow Frequency Analysis Time Series File:posteast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 1. 94 6 2/09/01 2:00 1.59 8 1/05/02 16:00 2.32 3 2/27/03 7:00 1. 73 7 8/26/04 2:00 2.08 4 10/28/04 16:00 2.06 5 1/18/06 16:00 2.52 2 10/26/06 0:00 3.90 l 1/09/08 6:00 Computed Peaks -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 3.90 l 100.00 0.990 2.52 2 25.00 0. 960 2.32 3 10.00 0.900 2.08 4 5.00 0.800 2.06 5 3.00 0.667 1. 94 6 2.00 0.500 1. 73 7 1. 30 0.231 1. 59 8 1.10 0. 091 3.44 50.00 0.980 Flow Frequency Analysis Time Series File:exeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks Rank Return Prob (CFS) (CFS) Period 0.675 2 2/09/01 18:00 0.970 1 100.00 0.990 0.232 7 1/05/02 16:00 0.675 2 25.00 0.960 0.564 3 2/28/03 3:00 0.564 3 10.00 0.900 0.060 8 8/26/04 2:00 0.541 4 5.00 0.800 0. 329 6 1/05/05 8:00 0.501 5 3.00 0.667 0.541 4 1/18/06 20:00 0. 329 6 2.00 0.500 0.501 5 11/24/06 4:00 0.232 7 1. 30 0.231 0.970 1 1/09/08 9:00 0.060 8 1.10 0.091 Computed Peaks 0. 872 50.00 0.980 Flow Frequency Analysis Time Series File:upsteast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.023 2 2/09/01 18:00 0.006 7 1/06/02 4:00 0.017 4 2/28/03 3:00 0.001 8 3/24/04 20:00 0.010 6 1/05/05 8:00 0.018 3 1/18/06 20:00 0.015 5 ll/24/06 6:00 0.029 1 1/09/08 9:00 Computed Peaks -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 0.029 1 100.00 0.990 0.023 2 25.00 0. 960 0.018 3 10.00 0.900 0.017 4 5.00 0.800 0.015 5 3.00 0.667 0.010 6 2.00 0.500 0.006 7 1. 30 0. 231 0.001 8 1.10 0.091 0.027 50.00 0.980 DEVELOPED CONDITIONS The developed basin ridge delineated and allowed per SWM Adjustment L02V0024 was regraded at a different location than what currently exists. See Existing and Developed Conditions Exhibit on the following pages. The relocation was logical based on the property boundary and basin ridge relationship. A small triangle of area adjacent to the existing basin ridge within the existing West Basin is currently located at the most southwestern end of the property. This triangle of area is approximately 300' from the West Basin located within the property boundary, therefore this small area will be conveyed to the East Basin in the developed condition and an equal amount of area within the existing East Basin located along adjacent to the basin ridge at the north end of the site will be conveyed to the West Basin. Since an adjustment was required to relocate the basin ridge, an automatic 10% safety factor was added to the detention calculations. The maximum impervious area per lot was calculated using the criteria in the 1998 ](jng County Surface Water Design Manual page 3-27 and K.C.C.2 lA.12.030. The proposed development is urban residential. The site is R-6 zoning. The maximum impervious area per lot is 70%. WEST BASIN The lots within the West Basin cover a total area of 1.15 acres. Maximum Lot Impervious Area= 70%*1.15 acres= 0.81 acre West Basin Impervious Area Delineation Onsite road and sidewalk 0.49 acres Impervious area oflots 0.81 acres Total impervious area 1.30 acres The input used for the KCRTS analysis is summarized in the table below: WEST BASIN To ta! Area = I. 81 acres DEVELOPED CONDITIONS (devwest) GROUND COVER AREA(acre) Till-Grass (Landscapine:) 0.51 Impervious 1.30 21A.12.030 A. Densities and dimensions -residential zones . --~-:. RESIDENTIAL z RURAL 0 URBAN URBAN N RESERVE R!S10EN11AI. E s ' STANDARDS RA·2.5 .... RA-10 RA-20 UR •. , .... ~ ... R-12 .. ,. R-24 ..... 1171 Base Denstty: D..2 D..2 u o.os D..2 , • • • 12 18 .. .. -----dWK ·------du/ac -Unl1/ .... (21) ti) (1S) Maximum Density: 0A 0A • 9 12 11 27 ,. 72 Dwelflng Unlt/Acr9 ------"""' ..... ·-(1) (20) (20) (22) IUnlmum Detwly: --.... '"' "'" -...,, (2) (12) (12) (12) MIi) (18) M•l (18) 118) (111) (18) (23) Minimum Lot 1:1,n 135ft ,,.. '135ft 35ft 35ft ,Oft ,Oft ,Oft ,Oft ... 30ft "'ft Wldlh (7) (7) (>) . Minimum street ,Oft ,Oft ,.. 30ft 30ft 20ft 10ft 10ft 10ft 10ft 10ft 10ft 10ft -(1) (9) (9) (9) (7) (7) (8) (8) (II) (8) (8) (II) (I) (>) lllnlmum-Sft 10ft 10 ft 10 ft 5ft .ft 5ft •• 8ft Sft 5ft .. 5ft ....... (9) (9) (9) (9) (7) (7) (10) (10) (10) (10) (3) (18} BaNHoight .. ft .. ft ... <Oft 35ft 35ft "'ft 35ft 35ft 6Gft 80ft ... 80ft (4) 48ft 45ft 80ft 80ft 80ft (1Al (1-1) {14) 11•1 (1-1) / -..,m '\ .... "" "" 12.5% '°" ""' "" 70% "" "" "" "" -I lmpervlous (11) {11) (11) M1) (11) (11) .__./ Surtace: (19) (18) (19) (19) ' Pffl:entage (S) I 12-2 (King County 6-00) Flow Frequency Analysis Time Series File:devwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks Rank Return Prob (CFS) (CFS) Period 0.361 6 2/09/01 2:00 0. 722 1 100.00 0.990 0.301 8 1/05/02 16:00 0.485 2 25.00 0. 960 0.432 3 2/27/03 7:00 0.432 3 10.00 0.900 0.333 7 8/26/04 2:00 0.399 4 5.00 0.800 0.399 4 10/28/04 16:00 0.384 5 3.00 0.667 0.384 5 1/18/06 16:00 0.361 6 2.00 0.500 0.485 2 10/26/06 0:00 0.333 7 1. 30 0.231 0.722 1 1/09/08 6:00 0.301 8 1.10 0.091 Computed Peaks 0.643 50.00 0.980 EAST BASIN The lots within the East Basin cover a total area of 6.62 acres. Maximum Lot Impervious Area= 70%*6.62 acres = 4.63 acres East Basin Imnervious Area Delineation Onsite road and sidewalk 2.06 acres Imoervious area of lots 4.63 acres Total impervious area 6.69 acres The input used for the KCRTS analysis is summarized in the table below: EAST BASIN Total Area= I 0.06 acres DEVELOPED CONDITIONS (deveast) GROUND COVER AREA(acre) Till-Grass (Landscaoing) 3.37 lmoervious 6.69 Flow Frequency Analysis Time Series File:deveast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 1. 92 6 2/09/01 2:00 3. 88 1 100.00 0.990 1. 58 8 1/05/02 16:00 2.52 2 25.00 0.960 2.31 3 2/27/03 7:00 2.31 3 10.00 0.900 1. 73 7 8/26/04 2:00 2.08 4 5.00 0.800 2.08 4 10/28/04 16:00 2.05 5 3.00 0.667 2.05 5 1/18/06 16:00 1. 92 6 2.00 0.500 2.52 2 10/26/06 0:00 1.73 7 1. 30 0.231 3.88 1 1/09/08 6:00 1.58 8 1.10 0. 091 Computed Peaks 3.42 50.00 0.980 B. Detention Routing Calculatious Per the Hearing Examiner's Conditions, the West Basin wetvault will mitigate for increased drainage flows from the developed West Basin utilizing Level 3 Flow Control. The East Basin wetpond will mitigate for increased drainage flows from the developed East Basin utilizing Level 2 Flow Control. All storn1water mitigation facilities will be designed according to the 1998 KCSWDM. Since an adjustment was required to relocate the basin ridge, an automatic 10% safety factor was added to the detention calculations. WEST BASIN The West Basin will utilize a wetvault to accommodate the required Level 3 Flow Control. The West Basin wetvault (wvault.rdf) was sized based on the 1998 KCSWDM and KCRTS Computer Software Reference Manual. See attached KCRTS printouts. The wetvault per KCRTS will have a surface area of2,967 square feet and a depth of7.42 feet. To accommodate the required 10% safety factor, the vault will be constructed with a surface area of3,264 square feet (34 feet by 96 feet). West Basin Wetvault Overflow Elevation The primary overflow for the vault is the riser pipe within the control structure. The water surface elevation above the riser for the 100 year developed flow is calculated assuming all orifices are plugged. To pass the 100-year return period storm, 0. 72 cfs, through a 12" overflow riser will require 0.47 feet of head (From Figure 5.3.4.H in the 1998 KCSWDM: Qweir = 9.739DH 312 => 0.72 = 9.739(12/12)H 312 => H = 0.18 feet). The primary overflow elevation would therefore, be equal to the elevation of the top of the riser plus the amount of head required to pass the I 00-year return period storm, Elev. 478.47 + 0.18 feet= Elev. 478.65. The ceiling of the vault is located at elevation 459.0 and will accommodate the required overflow elevation. Retention/Detention Facility lj.:)\J (-\L)LT. DO(., Type of Facility: Facility Length: Facility Width: Facility Area: Effective Storage Depth: Stage O Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Detention Vault 87.27 ft 34.00 ft 2967. sq. 7.42 ft 471.08 ft 22016. cu. 7.39 ft ft ft 12.00 inches 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 0.81 0.048 2 3.60 1.20 0.076 4.0 3 5.20 a.so 0.010 4.0 Top Notch Weir: None Outflow Rating .Curve: None Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 471.08 89. 0.002 0.000 0.00 0.01 471. 09 119. 0.003 0.002 0.00 0.02 471.10 148. 0.003 0.002 0.00 0.03 471.11 178. 0.004 0. 003 0.00 0.04 4 71.12 2o·s. 0.005 0.004 0.00 0.05 471.13 237. 0.005 0. 004 0.00 0.06 471.14 267. 0.006 0. 004 0.00 0.07 471.15 297. 0.007 0.005 0.00 0.21 471.29 712. 0.016 0.008 0.00 0.36 471.44 1157. 0.027 0. Oll 0.00 0.50 471.58 1573. 0.036 0.013 0.00 0.65 471.73 2018. 0.046 0.014 0.00 0.79 471.87 2433. 0.056 0.016 0.00 0.94 4 72. 02 2878. 0.066 0.017 0.00 1. OB 472.16 3294. 0.076 0.019 0.00 1. 23 472.31 3739. 0.086 0. 020 0.00 1. 37 472.45 4154. 0.095 0. 021 0.00 1. 52 472.60 4599. 0.106 0.022 0.00 1.66 472.74 5015. 0.115 0.023 0.00 1.81 4 72. 89 5460. 0.125 0.024 0.00 1. 95 473.03 5875. 0 .135 0. 025 0.00 2.10 473.18 6320. 0.145 0.026 0.00 2.24 473.32 6736. 0.155 0.027 0.00 2.39 473.47 7181. 0.165 0.027 0.00 2.53 473.61 7596. 0.174 0.028 o.oo 2.68 473.76 8041. 0.185 0.029 0.00 2.82 473.90 8457. 0.194 0.030 0.00 2.97 474.05 8902. 0.204 0.031 0.00 3.11 474.19 9317. 0. 214 0.031 0.00 3.26 474.34 9762. 0.224 0.032 0.00 3.40 474.48 10177. 0.234 0.033 0.00 3.55 474.63 10623. 0.244 0.034 0.00 3.60 474.68 10771. 0.247 0.034 o.oo 3.61 474.69 10801. 0.248 0.034 0.00 3.63 474.71 10860. 0. 249 0.035 0.00 3.64 474.72 10890. 0.250 0.037 0.00 3.65 474.73 10919. 0.251 0.039 0.00 3.66 474.74 10949. 0.251 0.041 0.00 3.68 474.76 11008. 0.253 0.045 0.00 3.69 474.77 11038. 0.253 0.046 0.00 3.70 474.78 11068. 0.254 0.047 0.00 3.84 474.92 11483. 0.264 0.054 0.00 3.99 475.07 11928. 0.274 0.060 0.00 4.13 475.21 12343. 0.283 0.065 0.00 4.28 475.36 12789. 0. 294 0.069 0.00 4.42 475.50 13204. 0.303 0.073 0.00 4.57 475.65 13649. 0.313 0.076 0.00 4.71 475.79 14064. 0.323 0.080 0.00 4.86 475.94 14510. 0.333 0.083 0.00 5.00 476.08 14925. 0.343 0.086 0.00 5.15 476.23 15370. 0.353 0.089 0.00 5.20 476.28 15518. 0.356 0.090 0.00 5.21 476.29 1554 8. 0.357 0.090 0.00 5.22 476.30 15578. 0.358 0.091 0.00 5.23 476.31 15607. 0.358 0.092 0.00 5.24 476.32 15637. 0.359 0. 092 0.00 5.39 476.47 16082. 0.369 0. 096 0.00 5.53 476.61 16498. 0.379 0.100 0.00 5.68 476.76 16943. 0.389 0.103 o.oo 5.82 476.90 17358. 0.398 0.106 0.00 5.97 477.05 17803. 0.409 0.109 0.00 6 .11 477.19 18218. 0. 418 0 .112 0.00 6.26 477.34 18664. 0.428 0 .115 0.00 6.40 477.48 19079. 0.438 0.118 0.00 6.55 477.63 19524. 0.448 0 .120 0.00 6.69 477.77 19939. 0.458 0 .123 0.00 6.84 4 77. 92 20385. 0.468 0.125 0.00 6.98 478.06 20800. 0.478 0.128 0.00 7.13 478.21 21245. 0.488 0.130 0.00 7.27 478.35 21660. 0. 497 0 .133 0.00 7. 39 478.47 22016. 0.505 0 .134 0.00 7.49 478.57 22313. 0.512 0.444 0.00 7.59 478.67 22610. 0.519 1.010 0.00 7.69 478.77 22907. 0.526 1. 740 0.00 7.79 478.87 23203. 0.533 2.530 0.00 7.89 478.97 23500. 0.539 2.820 0.00 7.99 479.07 23797. 0.546 3.070 0.00 8.09 479.17 24094. 0.553 3.310 0.00 8.19 479.27 24390. 0.560 3.530 0.00 8.29 479.37 24687. 0.567 3.740 0.00 8.39 479.47 24 984. 0.574 3.930 0.00 8. 49 479.57 25280. 0.580 4.120 0.00 8.59 479.67 25577. 0.587 4.290 0.00 8.69 479.77 25874. 0.594 4.470 0.00 8.79 479.87 26171. 0.601 4.630 0.00 8.89 479.97 26467. 0.608 4.790 0.00 8.99 480.07 26764. 0. 614 4. 94 0 0.00 9.09 480.17 27061. 0.621 5.090 0.00 9.19 480.27 27357. 0.628 9.29 480.37 27654. 0.635 Hyd Inflow Outflow Peak Target Cale Stage Elev 1 0. 72 0.22 0.22 7.42 478.50 2 0.36 ******* 0 .12 6.54 477.62 3 0.37 ******* 0 .11 5.87 476.95 4 0.38 ******* 0.09 5.07 476.15 5 0.43 ******* 0.09 5.01 476.09 6 0.23 ******* 0.06 3.91 474.99 7 0.30 ******* 0.03 3.29 474.37 8 0.33 ******* 0. 03 2.75 473.83 Route Time Series through Facility Inflow Time Series File:devwest.tsf Outflow Time Series File:wout Inflow/Outflow Analysis Peak InflOw Discharge: Peak Outflow Discharge: Peak Reservoir Stage: Peak Reservoir Elev: 0.722 CFS 0.222 CFS 7.42 Ft 478.50 Ft at at Peak Reservoir Storage: 22102. Cu-Ft 0.507 Flow Frequency Analysis Time Series File:wout.tsf Project Location:Sea-Tac Ac-Ft 5.230 0.00 5.370 0.00 Storage (Cu-Ft) (Ac-Ft) 22102. 0.507 19496. 0.448 17498. 0.402 15128. 0.347 14956. 0.343 11683. 0.268 9839. 0.226 8260. 0.190 6,00 on Jan 9 in Year 8 11,00 on Jan 9 in Year 8 ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks --Rank Return Prob (CFS) (CFS) (ft) Period 0.120 2 2/09/01 20,00 0.222 7.42 1 100.00 0.990 0.032 7 12/28/01 18,00 0.120 6.54 2 25.00 0. 960 0.086 5 3/06/03 22,00 0.107 5.87 3 10.00 0.900 0.030 8 8/26/04 7,00 0.087 5.07 4 5.00 0.800 0.057 6 1/05/05 15,00 0.086 5.01 5 3.00 0.667 0.087 4 1/18/06 23,00 0.057 3.91 6 2.00 0.500 0.107 3 11/24/06 7,00 0.032 3.29 7 1. 30 0.231 0.222 1 1/09/08 11,00 0.030 2.77 8 1.10 0.091 Computed Peaks 0.188 7. 41 50.00 0.980 Flow Duration from Time Series File,wout.tsf Cutoff Count Frequency CDF Exceedence Probability CFS % % % 0.002 34644 56.497 56.497 43.503 0.435E+OO 0.005 4824 7:867 64.364 35.636 0.356E+OO 0.008 5399 8.805 73.169 26.831 0.268E+OO 0.012 3897 6.355 79.524 20.476 0.205E+OO 0.015 4088 6.667 86.190 13.810 0.138E+OO 0.018 2706 4.413 90.603 9.397 0.940E-01 0.022 2069 3.374 93.977 6.023 0.602E-01 0.025 1286 2.097 96.075 3. 925 0.393E-01 0.028 1042 1. 699 97.774 2.226 0.223E-01 0.032 703 1.146 98. 920 1. 080 O.lOBE-01 0.035 327 0.533 99.454 0.546 0.546E-02 0.039 7 0. 011 99.465 0.535 0.535E-02 0.042 11 0.018 99.483 0.517 0.517E-02 0.045 12 0.020 99.503 0.497 0.497E-02 0. 049 32 0.052 99.555 0.445 0.445E-02 0.052 35 0.057 99.612 0.388 0.388E-02 0.055 31 0.051 99.662 0.338 0.338E-02 0.059 20 0.033 99.695 0.305 0.305E-02 0.062 13 0.021 99. 716 0.284 0.284E-02 0.065 12 0.020 99.736 0.264 0.264E-02 0.069 16 0.026 99.762 0.238 0.238E-02 0.072 16 0.026 99.788 0. 212 0. 212E-02 0.075 18 0. 029 99.817 0.183 0 .183E-02 0.079 18 0. 029 99.847 0.153 0.153E-02 0.082 19 0.031 99.878 0.122 0.122E-02 0.085 10 0.016 99. 894 0.106 0.106E-02 0.089 17 0.028 99.922 0.078 0.783E-03 0. 092 5 0.008 99.930 0.070 0. 701E-03 0.095 10 0.016 99.946 0.054 0.538E-03 0.099 3 0.005 99.951 0. 049 0.489E-03 0.102 7 0.011 99.962 0.038 0.375E-03 0.105 5 0.008 99.971 0.029 0. 294E-03 0.109 6 0.010 99.980 0.020 0 .196E-03 0.112 2 0.003 99.984 0.016 0.163E-03 0.116 3 0.005 99.989 0. 011 0 .114E-03 0.119 4 0.007 99.995 0.005 0.489E-04 Duration Comparison Anaylsis Base File: exwest.tsf New File: wout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time--------------Check of Tolerance------- Cutoff Base New %Change Probability 0.034 0.81E-02 0.71E-02 -12.1 I 0.81E-02 0.041 0.59E-02 0.52E-02 -11.1 I 0.59E-02 0.048 0.46E-02 0.45E-02 -2.8 I 0.46E-02 0.056 0.34E-02 0.33E-02 -2.4 I 0.34E-02 0.063 0.26E-02 0.28E-02 5.6 I 0.26E-02 0.070 0.19E-02 0.23E-02 19.8 I 0.19E-02 0.078 0.14E-02 0.16E-02 15.3 I 0.14E-02 0.085 0.96E-03 O.llE-02 10.2 I 0.96E-03 0. 092 0.68E-03 0.68E-03 0.0 I 0.68E-03 0.100 0.41E-03 0.47E-03 16.0 I 0.41E-03 0.107 0.21E-03 0.26E-03 23.1 I 0.21E-03 0.114 0.15E-03 0.13E-03 -11.1 I 0.15E-03 0.121 0.65E-04 O.OOE+OO -100.0 I 0.65E-04 Maximum positive excursion= 0.004 cfs ( 6.4%) occurring at 0.070 cfs on the Base Data:exwest.tsf and at 0.075 cfs on the New Data:wout.tsf Maximum negative excursion= 0.008 cfs (-18.7%) occurring at 0.043 cfs on the Base Data:exwest.tsf and at 0.035 cfs on the New Data:wout.tsf Base New %Change 0.034 0.033 -1. 4 0.041 0.034 -17.3 0.048 0.048 -1. 3 0.056 0.055 -1. 4 0.063 0.066 4.9 0.070 0.075 6.0 0.078 0.081 3.7 0.085 0.086 1. 3 0. 092 0 .. 092 0.0 0.100 0.102 2.3 0.107 0.109 1. 7 0 .114 0 .113 -0.6 0.121 0 .119 -2.4 7 ' N I R ____ _ 8:-r---:;:2:~:;-------- N 0 wout.dur + wtarget.dur x O-f-.Dlll]...._ ________ ........::5i:,------------------- o- 0 0 "~:-t-----------------'\:----------------- (./) <O LL u '-' g 00 ----- • Probability Exceedence o·+-"'-'-.----..--r.n,nr---,--,-r,--,m-rr--.----r--.,.,..,..,.,.,---,----,r-r-,--,....;.r,--~~..,:r:.,.~= VAULT FREQUENCY/ DURATION COMPARISON EVENDELL CORE PROJECT NO. 04009 1 Retention/Detention Facility Type of Facility: Side Slope: Pond Bottom Length: Pond Bottom Width: Pond Bottom Area: Top Area at 1 ft. FB: Effective Storage Depth: Stage O Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Detention Pond 3.00 H:lV 165.00 ft 78.00 ft 12870. sq. ft 25135. sq. ft 0.577 acres 6.15 ft 452.00 ft 109514. cu. ft 2.514 ac-ft 6.15 ft 18.00 inches 3 Pipe Orifice # Height (ft) Diameter ( in) 1. 75 3.00 2.00 Full Head Discharge (CFS) 0.206 0.358 0 .111 Diameter (in) 1 0.00 2 4.00 3 5.10 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage (ft) (ft) (cu. ft) (ac-ft) 0.00 452.00 0. 0.000 0.02 452.02 258. 0.006 0.04 452. 04 516. 0.012 0.05 452.05 645. 0.015 0.07 452.07 905. 0.021 0.09 452.09 1164. 0.027 0 .11 452 .11 1425. 0.033 0 .13 452.13 1685. 0.039 0.15 452.15 1947. 0.045 0.27 452.27 3528. 0.081 0. 39 452.39 5131. 0 .118 0.51 452.51 6755. 0.155 0.63 452.63 8400. 0.193 0.75 452.75 10068. 0.231 0.87 452.87 11757. 0.270 0.99 452.99 13467. 0.309 1.11 453.11 15200. 0. 349 1. 23 453.23 16955. 0.389 1.35 453.35 18733. 0.430 1.47 453.47 20532. 0.471 1.59 453.59 22355. 0 .513 1. 71 453.71 24199. 0.556 1.83 453.83 26067. 0.598 1.95 453.95 27958. 0.642 2.08 454.08 30032. 0.689 2. 20 454.20 31970. 0.734 2.32 454.32 33932. 0.779 6.0 4.0 Discharge (cfs) 0.000 0. 011 0.016 0.019 0.022 0.025 0.027 0.030 0.032 0.043 0.052 0.059 0.066 0. 072 0. 077 0.083 0.088 0. 092 0.097 0.101 0.105 0.10~ 0 .112 0 .116 0 .120 0.123 0.126 Percolation (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 o.oo 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Surf Area (sq. ft) 12870. 12899. 12 92 8. 12943. 12 972. 13002. 13031. 13060. 13090. 13266. 13444. 13623. 13803. 13984. 14166. 14349. 14533. 14718. 14904. 15091. 15279. 15468. 15659. 15850. 16058. 16252. 16446. 2.44 454.44 35917. 0.825 0.130 0.00 16642. 2.56 454.56 37926. 0.871 0.133 0.00 16838. 2.68 454. 68 39959. 0.917 0.136 0.00 17036. 2.80 454.80 42015. 0. 965 0.139 0.00 17235. 2.92 454.92 44095. 1.012 0 .142 0.00 17434. 3.04 455.04 46199. 1.061 0.145 0.00 17635. 3.16 455.16 48327. 1.109 0 .148 0.00 17837. 3.28 455.28 50480. 1.159 0.150 0.00 18040. 3.40 455.40 52657. 1.209 0.153 0.00 18243. 3.52 455.52 54858. 1.259 0.156 0.00 18448. 3.64 455.64 57085. 1. 310 0.159 0.00 18654. 3.76 455.76 59335. 1. 362 0.161 0.00 18861. 3.88 455.88 61611. 1. 414 0.164 o.oo 19069. 4.00 456.00 63912. 1. 467 0.166 0.00 19278. 4.03 456.03 64491. 1. 481 0.169 0.00 19330. 4.06 456.06 65072. 1. 494 0.176 0.00 19383. 4.09 456.09 65654. 1. 507 0.189 0.00 19435. 4 .13 456.13 66433. 1.525 0. 205 0.00 19506. 4.16 456.16 67019. 1.539 0.225 0.00 19558. 4.19 456.19 67606. 1. 552 0. 249 0.00 19611. 4.22 456.22 68196. 1.566 0.275 0.00 19664. 4.25 456.25 68786. 1.579 0. 293 0.00 19717. 4.37 456.37 71165. 1. 634 0.322 0.00 19929. 4.49 456.49 73569. 1.689 0.347 o.oo 20142. 4.61 456.61 75999. 1.745 0.369 0.00 20356. 4.73 456.73 78455. 1.801 0.390 0.00 20572. 4.85 456.85 80936. 1.858 0.408 0.00 20788. 4.97 456.97 83444. 1.916 0.426 0.00 21005. 5.09 457.09 85978. 1.974 0.443 0.00 21224. 5.10 457.10 86190. 1. 979 0.444 0.00 21242. 5.12 457.12 86615. 1.988 0.447 0.00 21279. 5 .14 457.14 87041. 1. 998 0.452 0.00 21315. 5.16 457.16 87468. 2.008 0.459 0.00 21352. 5.18 457.18 87895. 2.018 0.468 0.00 21388. 5.20 457.20 88323. 2.028 0.478 0.00 21425. 5.23 457.23 88967. 2.042 0.489 0.00 21480. 5.25 457.25 89397. 2.052 0.501 0.00 21517. 5.27 457.27 89828. 2.062 0.510 0.00 21553. 5.39 457.39 92427. 2.122 0.538 0.00 21774. 5.51 457.51 95054. 2.182 0.564 0.00 21997. 5.63 457.63 97707. 2.243 0.587 0.00 22220. 5.75 457.75 100386. 2.305 0.609 0.00 22444. 5.87 457.87 103093. 2.367 0.630 0.00 22669. 5.99 457.99 105827. 2.429 0.650 0.00 22895. 6.11 458 .11 108588. 2 .493 0.669 0.00 23122. 6.15 458.15 109514. 2.514 0.675 0.00 23198. 6.25 458.25 111844. 2.568 1.150 0.00 23389. 6.35 458.35 114192. 2.621 2.010 0.00 23580. 6.45 458.45 116560. 2.676 3.120 0.00 23772. 6.55 458.55 11894 7. 2.731 4.430 0.00 23964. 6.65 458.65 121353. 2.786 5.910 0.00 24158. 6.75 458.75 123778. 2.842 7.350 0.00 24352. 6.85 458.85 126223. 2. 8 98 7.890 0.00 24547. 6.95 458.95 128687. 2.954 8.400 0.00 24742. 7.05 459.05 131171. 3. Oll 8.870 0.00 24938. 7.15 459.15 133675. 3.069 9. 320 0.00 25135. 7.25 459.25 136199. 3 .127 9.750 0.00 25333. 7.35 459.35 138742. 3.185 10.160 0.00 25531. 7.45 459.45 141305. 3.244 10.550 0.00 25730. 7.55 459.55 143888. 3.303 10.930 0.00 25930. 7.65 459.65 146491. 3.363 11.290 o.oo 26131. 7.75 459.75 149114. 3.423 11.640 0.00 26332. 7.85 459.85 151757. 3.484 11. 990 0.00 26534. 7.95 459.95 154421. 3.545 12.320 0.00 26736. 8.05 460.05 157104. 3.607 12.640 0.00 26940. 8.15 460.15 159809. 3.669 12.960 0.00 27144. Hyd Inflow Outflow Peak Storage Target Cale Stage Elev (Cu-Ft) (Ac-Ft) 1 3.90 ******* 2. 62 6.40 458.40 115486. 2.651 2 1. 94 ******* 0.67 6.14 458.14 109398. 2.511 3 1. 96 0.58 0.58 5.60 457.60 96982. 2.226 4 2.32 ******* 0.50 5.25 457.25 89499. 2.055 5 2.06 ******* 0.42 4.96 456.96 83147. 1.909 6 1. 22 0.17 0.20 4 .13 456.13 66386. 1.524 7 1. 59 ******* 0.16 3.61 455.61 56504. 1. 297 8 1. 73 ******* 0.14 2. 92 454. 92 44126. 1.013 Duration Comparison Anaylsis Base File: preeast.tsf New File: eout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time--------------Check of Tolerance------- Cutoff Base New %Change Probability Base New %Change / 0.170 0.82E-02 0.52E-02 -36.7 I 0.82E-02 0.170 0.160 -5.8 0.187 0.70E-02 0.44E-02 -36.3 I 0.70E-02 0.187 0.164 -12.6 0.204 0.62E-02 0.38E-02 -38.5 I 0.62E-02 0. 204 0.165 -19.2 0.222 0.55E-02 0.37E-02 -32.2 I 0.55E-02 0.222 0.168 -24.3 0.239 0.50E-02 0.36E-02 -28.1 I 0.50E-02 0.239 0.174 -26. 9 0.256 0.45E-02 0.35E-02 -22.7 I 0.45E-02 0.256 0.183 -28.4 0.273 0.40E-02 0. 34E-02 -13. 5 0.40E-02 0.273 0.201 -26.4 0. 290 0.36E-02 0. 34E-02 -5.5 0.36E-02 0.290 0.248 -14.5 0.307 0.31E-02 0.31E-02 0.5 0. 31E-02 0.307 0.308 0.5 0.324 0.28E-02 0.29E-02 4.7 0.28E-02 0.324 0.339 4.6 0.341 0.25E-02 0.27E-02 9.2 0.25E-02 0. 341 0.361 5.8 0.358 0.23E-02 0.25E-02 10.8 0.23E-02 0.358 0.375 4.7 0.375 0.20E-02 0.23E-02 15.0 0.20E-02 0.375 0.387 3.3 0.392 0.17E-02 0.19E-02 9.6 0.17E-02 o. 392 0.399 1. 9 0.409 0.14E-02 0.14E-02 3.5 0.14E-02 0.409 0.412 0.7 0.426 0.12E-02 0 .12E-02 -4. 0 0.12E-02 0.426 0.422 -1. 0 0.443 O.lOE-02 0.99E-03 -1. 6 O.lOE-02 0.443 0.441 -0.5 0 .460 0.90E-03 0.90E-03 0.0 0.90E-03 0.460 0.464 0.9 0.477 0.82E-03 0.83E-03 2.0 0.82E-03 0.477 0.478 0.2 0. 494 0.62E-03 0. 72E-03 15.8 0.62E-03 0. 494 0.519 5.0 0 .511 0.52E-03 0. 64E-03 21. 9 0.52E-03 0 .511 0.531 4.0 0.528 0.39E-03 0.55E-03 41. 7 0.39E-03 0.528 0.560 6.0 0.545 0.33E-03 0.44E-03 35.0 0.33E-03 0.545 0.574 5.3 0.562 0.24E-03 0.38E-03 53.3 0.24E-03 0.562 0.594 5.7 0.579 0.20E-03 0.29E-03 50.0 0.20E-03 0.579 0.618 6.6 0.596 0.15E-03 0.23E-03 55.6 0.15E-03 0.596 0.639 7.1 0. 613 0.13E-03 0.20E-03 50.0 0.13E-03 0.613 0.641 4.5 0.630 0. llE-03 0.15E-03 28.6 O.llE-03 0.630 0. 649 2.9 0.648 O.llE-03 0. llE-03 0.0 0. llE-03 0.648 0.649 0.2 0.665 0.49E-04 0.65E-04 33.3 0.49E-04 0.665 0.668 0.5 0.682 0.33E-04 O.OOE+OO -100.0 0.33E-04 0.682 0. 671 -1. 6 Maximum positive excursion = 0. 049 cfs 8.H) v occuring at 0.590 cfs on the Base Data:preeast.tsf and at 0.639 cfs on the New Data,eout.tsf Maximum negative excursion = 0.073 cfs (-28.4%) occuring at 0.256 cfs on the Base Data:preeast.tsf and at 0.183 cfs on the New Data:eout.tsf Flow Frequency Analysis Time series File:eout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.674 2 2/09/01 20:00 0.158 7 12/29/0110:00 0.503 4 3/06/03 22:00 0.142 8 8/26/04 7:00 0.204 6 1/08/05 3:00 0.424 5 1/18/06 23:00 0.581 3 11/24/06 8:00 2.61 1 1/09/08 10:00 computed Peaks EOUT. PKS -----Flow Frequency Analysis------- --Peaks --Rank Return Prob (CFS) (ft) Period 2.61 6.40 1 100.00 0.674• 6.15 2 25.00 0.580V 5.60 3 10.00 0.503 5.25 4 5.00 0.424 4.96 5 3.00 0.204,/ 4.13 6 2.00 0. 158 3. 61 7 1. 30 0.142 2.92 8 1.10 1.97 6.35 50.00 Page 1 0.990 0.960 0.900 0.800 0.667 0. 500 0. 231 0.091 0.980 Flow Frequency Analysis Time series File:preeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.698 2 2/09/01 18:00 0.238 7 1/05/02 16:00 0. 580 3 2/28/03 3:00 0.060 8 8/26/04 2:00 0.339 6 1/05/05 8:00 0.559 4 1/18/06 20:00 0. 516 5 11/24/06 4:00 0.999 1 1/09/08 9:00 Computed Peaks PREEAST.PKS -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 0.999 1 100.00 0.990 0.698 2 25.00 0.960 o. 580 ,,,, 3 10.00 0.900 0. 559 4 5.00 0.800 0. 516 5 3.00 0.667 0. 339,/ 6 2 .00 0. 500 0.238 7 1. 30 o. 231 0.060 8 1.10 0.091 0.899 50.00 0.980 Page 1 ELEVATION 459.0 . ~-r ..... ·- 458.0 -~-fr·· \. ,. •~ \,. ' ~-, . 456.0 455.0 454.0 ;_ ,;,, 452.0 Actual POND VOLUME CALCULATIONS CORE PROJECT NO. 04009 PROJECT NAME: EVENDELL . ' INCREMENTAL VOLUME SF CF 27600 '' • i . ~-· ' 26,450 25300' ' 1-~ ~1 ,. 51,511 ·~ 26211 ,. .. "h . . 24,109 22007 ' .. 20,064 ' .. , 18120 ""' 1i:Y : "11 ' . .. ,r '' 32,638 -_:,; 14518 , ,. .. t •·. . ' . "" . '• i 452.0 12140. . TOTAL VOLUME CF _n.·:· '_ 154,772 .-' ,,,;;:: '' If-".·. 128,322 • i \'-'-~ 76,811 -· ;;;• . 52,702 't ·, ;: ~j: q 32,638 . ' -""-- * ""~·.':~-?" i; -~-{ -f.-.,: _,,.{:J'lL, -'· ' .. -'\w; 21,095 36,110 ** 450.0 8955 ' ... ,·: ... '..;··, ~-rtr,;t. .. • 448.0 6060 , 'J ''.-• .J; ., 15,015 ·f'!-"' .. ' ,.!--'-., * = Total Live Storage m Pond **=Total Dead Storage in Pond t---------~ ,. ·-.....·~+ ,, 1.~ o·+-------"'\r;-~------- <0 0 l(1 eout..dur + etarget.dur x .... ,-oo-o======-------~-------------------0 0 ~~+---------------~~--------------- V)O LL ; ~ Ol.(} oo £-+--------------------~~~---------vci (f) ·-0 POND FREQUENCY/ DURATION COMPARISON EVENDELL CORE PROJECT NO. 04009 1 EAST BASIN The East Basin will utilize a wetpond to accommodate the required Level 2 Flow Control. The East Basin wetpond will receive runoff from the upstream tributary area as well as runoff from onsite. The upstream tributary area will be routed through the onsite storm drainage system to the wetpond. The allowable release rates will be established by the sum of the upstream tributary runoff plus the existing onsite runoff. The allowable release rate will be delineated as preeast.tsf and will be the sum of exeast.tsf + upsteast.tsf. The flows entering the wetpond will be the sum of the upstream tributary area and the developed site going to the pond. The total developed flows discharging to the pond will be delineated as posteast.tsf and will be the sum of deveast.tsf and upsteast.tsf. The East Basin wetpond (epond.rdf) was sized based on the 1998 KCSWDM and KCRTS Computer Software Reference Manual. See attached KCRTS printouts and attached pond volume calculation spreadsheet on the following pages. The stage-storage of the pond produced by KCRTS was utilized to calculate storage values at the elevations used to calculate the proposed wetpond that will actually be constructed onsite. The KCRTS interpolated storage values are listed below. Elevation Length x Width KCRTS Storage KCRTS Storage * I 0% Safety Factor 452 165'x78' 0 0 454 177' X 90' 29,000 CF 31,900 CF 456 189'xl02' 63,900CF 70,290 CF 458 20]' X 114' 106,000 CF 116,600 CF Per the proposed Pond Volume Calculations spreadsheet on the following pages, the storage values at each delineated elevation is more than the required 10% safety factor storage values calculated above. The pond is therefore, adequately sized to accommodate the required I 0% safety factor. East Basin Wetpond Overflow Elevations The primary overflow for the pond is the riser pipe within the control structure. The water surface elevation above the riser for the 100 year developed flow is calculated assuming all orifices are plugged. To pass the 100-year return period storm, 3.90 cfs, through a 18" overflow riser will require 0.47 feet of head (From Figure 5.3.4.H in the 1998 KCSWDM: Qweir = 9.739DH312 ~ 3.90 = 9.739(15/12)8312 ~ H = 0.41 feet). The primary overflow elevation would therefore, be equal to the elevation of the top of the riser plus the amount of head required to pass the 100-year return period storm, Elev. 458.15 + 0.41 feet= Elev. 458.55. The secondary overflow for the pond is the jailhouse weir located on the control structure catch basin. To pass the 100-year return period storm at 0.41 feet of head, a minimum 4.60-foot wide jailhouse weir will be required. The jailhouse weir is analyzed as a notch weir using the following equation: Q = C (L-0.2H)H312 where Q = flow (3.90 cfs) C = 3.27 + 0.40 HIP H = head above weir (0.41 ft¢:: Use Same Head as Req'd Head Over Riser) P = depth of storage at weir (Elev. 458.15 -Elev. 452.0 = 6.15 feet) L = length of the riser (ft) An emergency overflow spillway will be installed and constructed also as a 12-foot wide access road to the control structure. The emergency overflow/access road will be surfaced with asphalt. The emergency overflow spillway will be located at the primary and secondary overflow elevation 458.41. The 12' wide spillway can accommodate the 100-year return period flow of 3.90 cfs at a head of 0.2'. Qwo = C (2g)1'2 [(2/3)LH312 + (8/15)(Tan El)H 512 ] where Q 100 = peak flow (3.90 cfs) C=0.6 G = 32.2 ft/sec 2 H = head above weir L = length of weir (12 ft) El= angle of side slopes (Tan 0 = 10) 3.90= 0.6 (2*32.2)112 [(2/3)(I2)(H)312 + (8/l5)(I0)(H)5'2 ] H=0.2' C. Water Quality Volume Calculations Per the Water Quality Applications Map, Basic Water Quality Treatment shall be utilized to mitigate for the developed storm drainage flows. The wet portion of the wetpond and wetvault will satisfy this requirement. The required volume will be designed per KCSWDM Section 6.4.1.1. The following variables were used in the calculation: Volume Factor (f) = 3 Rainfall= 0.039 feet or 0.47 inches Area= developed basin Where Ai= area of impervious surface (sf) A,g = area of till soil covered with grass (sf) A,r= area of till soil covered with forest (sf) Ao= area of outwash soil covered with grass or forest (sf) V, = [0.9Ai + 0.25A,g + O.IA,r+ O.O!Ao] * (R/12) Vb= f*Vr WEST BASIN Vb= 3*[(0.9)(1.30) + (0.25)(0.51)]0.039 * (43560sf/ac) = 6,613 CF The dead storage portion of the wetvault is 4.06' deep and has a surface area of 17 feet by 96 feet. The dead storage therefore, has a volume of 6,626 CF which exceeds the required 6,613 CF. A minimum flow path length to width ratio of3:l is required for the wet portion of the vault. The average width is 17' and the length from inlet to outlet is 199'. The length to width ratio for the vault is therefore, 199' /17' = 11. 7: I which exceeds the required minimum 3:1. The sediment storage within the I st cell was designed with I' of average storage and the sediment storage within the 2nd cell was designed with 0.5' of average storage with bottom slopes within the vault sloping toward the exterior walls. See email on the following pages for allowance to slope the bottom toward the exterior walls rather than towards the center. The average bottom elevation within the!'' cell is (465.44 + 465.59 + 466.29 + 466.44)/4 = 465.94. The top of the sediment storage within the I st cell is elevation 467.02. The average storage depth within the !st cell is therefore, 467.02- 465.94 = 1.08' which exceeds the required I' average. The average bottom elevation within the 2"d cell (following the!'' cell) is (466.94 + 466.09)/2 = 466.52. The top of the sediment storage within the 2nd cell (following the I'' cell) is elevation 467.02. The average storage depth within the 2nd cell (following the I st cell) is therefore, 467.02 - 466.52 = 0.5 ', which is equal to the required 0.5' average. The average bottom elevation with the 2nd cell(detention only) is (471.00 + 470.15)/2 = 470.58. The top of the sediment storage within the 2"d cell (detention only) is elevation 471.08. The average storage depth within the 2"d cell is therefore, 471.08 -470.58 = 0.5', which is equal to the required 0.5' average. EAST BASIN Vb= 3*[(0.9)(6.69) + (0.25)(3.37))0.039 * (43560sf/ac) = 34,980 CF The dead storage portion of the wetpond has a volume of36,l lO CF which exceeds the required 34,980 CF. See Pond Volume Calculations spreadsheet in Section 4B of this report. LENGTH TO WIDTH RATIO A minimum flow path length to width ratio of 4:1 is required for the wet portion of the pond. (see the attached "Length to Width Ratio" exhibit). If this 4: I ratio can be achieved then it is not required for the pond to have a dividing berm. The location of the flow path and and the location that the width of the pond is measured is at one half the water depth. The MWS of the dead storage is 452.0 and the pond bottom is 448.0. Therefore the travel path and width is measured at elevation 450.0 (452.0 + 448.0 / 2). The travel path at this point is 195 feet and the average width of the pond is 39'. This calcu_lates to a length to width ratio of 5:1 (195/39 = 5.0) which is greater then the 4:1 required. 1 _ __.,..,/ I i I i I I I --------···· 0 '1. E:l u'S q'S &O t]~ 3'.) ? ..., !,l .. ~Liq ----------·~·-·-- I • DETENTION POND PLAN 1~5 -:::.. 3~ ~;O: \ J / 4-·.1 -J l !i ; -. ' C84 • ; f I >-=-'-- I I: ! I ! ! ! '-t-t-+-+, • I ! i: I I I I I I I L I ' I I I k ' I I ~· I RE: Evendell Vault Revision Page I of I CORE -Gina Brooks From: Hancock, Dave [Dave.Hancock@METROKC.GOV] Sent: Tuesday, July 20, 2004 7:08 AM To: CORE -Gina Brooks Cc: Walken, Jerry; Wong, Wylie Subject: RE: Evendell Vault Revision Gina, I have discussed your proposed revision to the vault design for the plat of Evendell with staff, and have determined that sloping the floor towards the exterior walls will not impact our ability to maintain the systemin the future. Sediment removal will be available through the access ports, also located along the exterior of the vault. I would recommend that Wylie document this revision by approving a minor field change, so the revision will not be challenged when the project is inspected at later dates. If you need additional assistance please feel free to e-mail me or call me at 206-296-8230. Dave Hancock -----Original Message----- From: CORE -Gina Brooks [mailto:grb@coredesigninc.com] Sent: Monday, July 19, 2004 1:39 PM To: dave.hancock@metrokc.gov Subject: Evendell Dave, I am hoping you can help me document your approval of the vault design for Evendell in regards to the bottom sloping towards the exterior walls rather than the interior. Per Jerry Walken, if I can get approval from maintenance for the sloping of the vault bottom towards the exterior walls then Comment 3 under Title "Sheet C4.32" of the !st Review Comments will become non-applicable. Please reply to this email with your approval so that I may attach this email to my response letter for Wylie Wong's review. Thanks for your help. Gina R. Brooks, P.E. Core Design, Inc. 14 711 NE 29th Place, Suite IO I Bellevue, WA 98007 425-885-7877 425-885-7963 (fax) 7/20/2004 £llhdl Ba, KING COUNTY WATER QUALITY APPLICATIONS MAP EVENDELL CORE PROJECT NO. 04009 ;ii;;: 0.,.. 6.4.1 WETPONDS -BASIC AND LARGE-METHODS OF ANALYSIS FIGURE 6.4.1.A PRECIPITATION FOR MEAN ANNUAL STORM IN INCHES (FEET) ST 1.1 0.54" (0.045') C:::z:J Incorporated Area ~ River/Lake Major Road 0.47" (0. 039') 0.47" (0. 039') NOTE: Areas east of the easternmost isopluvial should use 0.65 inches unless rainfaJI data is available for the location of interest ~ The mean annual storm is a conceptual storm found by dividing the annual precipitation by the total number of storm events per year ST 1. 0/ LA 0.52" (0.043'/i.56" (0.047') LA 1.0 LA 1.2 0 " 9 ~~~hUkHh C,>~N~? result, generates large amounts of runoff. For this application, till soil types include Buckley and bedrock soils, and alluvial and outwash soils that have a seasonally high water table or are underlain at a shallow depth (less than 5 feet) by glacial till. U.S. Soil Conservation Service (SCS) hydrologic soil groups that are classified as till soils include a few B, most C, and all D soils. See Chapter 3 for classification of specific SCS soil types. 1998 Surface Water Design Manual 9/1/98 .6-69 Wetland Recharge Calculations The following calculation compare the monthly volume of runnoff to the wetland before and after development. 4 lots have been selected to discharge roof and footing drains to recharge the wetland. Predeveloped Condition Total Upstream Area 54,000 sf Using the same relative landcovers as the east basin (see Drainage Report) Total Basin 10.06 Ac 6.62 Ac 3.26 Ac 0.18 Ac Therefore, Landcovers for Predeveloped Basin: Total Basin 1.24 Ac 0.82 Ac 0.40 Ac 0.02 Ac From WetPRE Timeseries, Total runoff for 8 Water Years= = 1.24 Ac % of Basin Forested 66% Pasture 32% Impervious 2% Forested Pasture Impervious % of Basin 66% 32% 2% Predeveloped Condition = 6.5 Ac-FT 2,949 cf/month Developed Condition Area east of wetland, unchanged in landcover Using the same relative landcovers as the east basin (see Drainage Report) Areas 0.38 Ac 0.25 Ac 0.12 Ac 0.01 Ac 4 Lots conveying to Wetland (Lots 34,35,37 and 38) Area (measured) 25,060 sf subract 4 driveways (20'x 30') 2400 sf Building Area 22,660 sf assume 70% buildings Total Basin (A+B) 15,862 sf 0.36 Ac 0.74 Ac 0.25 Ac 0.12 Ac 0.37 Ac = (A) Forested Pasture Impervious = = (B) Forested Pasture Impervious From WetDEV Timeseries, Total runoff for 8 Water Years= Developed Condition = 0.38 Ac 0.58 Ac 0.52 Ac 8.7 Ac-FT 3,948 cf/month ----=-=------/---·-- -:'."~::-:-:-:-----~-··-"'A > :-~>.•• 3 ',2 40 ,7[H S7: )Q, I :;;i <( 0 ~ 00 b4 ~ 56 "' 55 Sf 0 0 ~ 70 68 69 THA<:T G ' • "' r "· ----------- IE 12" 481.66 ~ ."' .. i(--:-.. ·--·-~---------- ..., "' .,; 0, .... w\ \ . ~l 1 --... ~-1,·v--.. ---·~i z\ \ I 29 . I / A 1 1I 28 I J___----;;, I 5. CONVEYANCE SYSTEM ANALYSIS AND DESIGN: ON-SITE DRAINAGE SYSTEM The conveyance system for the site was designed for both the 25-year, 24-hour storm and the 100-year, 24-hour storm. A backwater analysis sheet was generated for both the 25- year and 100-year return period storms. Total flows from each basin and upstream tributary area using 15-minute time steps were calculated. The inputs to calculate the total flows were the same for the West Basin and Upstream Tributary Area (See Section 4 ofthis report) but, varied for the East Basin. The total flows calculated for the East Basin excludes the Storm and Recreational Tracts (Tracts L & M) since these areas do not enter the conveyance system. The inputs used for the KCRTS analysis for the East Basin is sununarized in the table below: REVISED EAST BASIN Total Area= 8.94 acres DEVELOPED CONDITIONS (deast15) GROUND COVER AREA/acre) Till-Grass (Landscapini,) 2.25 Imoervious 6.69 The West Basin flow frequency analysis is attached as dwest15.tsf. The total KCRTS 25- year return period flow and thelOO-year return period flow for the West Basin are 1.28 cfs and 1.79 cfs consecutively. The East Basin flow frequency analysis is attached as <least 15. tsf. The East Basin Upstream Tributary flow frequency analysis is attached as upeastl5.tsf. And the combination of both time series for onsite and upstream areas for the East Basin is attached as postel5.tsf. The total KCRTS 25-year return period flow and the 100-year return period flow for the East Basin are 6.54 cfs and 9.06 cfs consecutively. For simplicity, large basin areas going to multiple catch basins were used. For the West Basin, it was simply assumed that the total flows for the entire basin enter all drainage pipe. Flows for the large areas within the East Basin were simply calculated as a portion of the overall 15-minute flows based on the area ratio. There will be four large basins delineated for the East Basin. See Catch Basin Subbasin Map on the following pages. The flows for each sub basin is calculated below. Subbasin Subbasin Percent 25-year Percent 100-year Return Area Area/East Basin Return Period Period Flow Flow Basin A 0.51 AC 0.51/8.94 = 5.70%*6.54 = 5.70%*9.06 = 0.52 cfs 5.70% 0.37 cfs BasinB 0.80AC 0.80/8.94 = 8.95%*6.54 = 8.95%*9.06 = 0.81 cfs 8.95% 0.59 cfs Basin C 3.87 AC 3.87/8.94 = 43.29%*6.54 = 43.29%*9.06 = 3.92 cfs 43.29% 2.83 cfs Basin D 3.76AC 3.76/8.94 = 42.06%*6.54 = 5.70%*9.06 = 3.81 cfs 42.06% 2.75 cfs Total 8.94AC 8.94/8.94 = 6.54 cfs 9.06 cfs 100% The tailwater elevations within the wetpond and wetvault were derived from the KCRTS outfall information (wout.tsf and eout.tsf). The tailwater elevations within the wetvault for the 25-year and 100-year return periods are El. 477.62 and El. 478.50 consecutively. The tailwater elevations within the wetpond for the 25-year and 100-year return periods are El. 458.15 and EL 458.40, respectively. The backwater analysis was performed to ensure that during the 25-year design storm, the maximum water surface elevation in each stmcture did not exceed an elevation equal to 0.5' less the rim and during the 100-year design storm, ensuring that if the maximum water surface elevation does exceed the rim, topography of the basin would allow the overflow to be conveyed to the next downstream catch basin or the topography would allow for ponding without causing structural damage. During the 25-year, the headwater elevations do not exceed 0.5' less the rim. During the 100-year, the headwater elevations exceed the rims of CB 3, CB 30 and CB 31. Overflow at CB 3 will simply drain to the next downstream catch basin. Drainage overflowing CB 30 and CB 31 will pond and overflow the crown of the road before jumping the curb and flow to the next downstream catch basin. ····· ... ,, ... ~ os x.nrn: I I OBNllMBER: \oN PJPE b HEADWATER FROM TO FLOW L ENGTJ; ELEVATION CB CB {CFS) {FEE!b-) ffEET) RIMEL SA 4 0.52 2 .00 4S9.39 462.00 4 3 0.52 s"i.OO 459.42 459.JO . Outfall SA 8.54 B3 .17 459.34 463.41 • 5A 5 4.73 .05 461.35 465.56 5 6 J.81 i':' .00 461.14 463.15 6 7 3.81 24 .00 462.04 463.15 7 8 J.81 44 .00 462.84 463.36 8 9 3.81 142 .20 464.61 466.16 . 9 10 J.81 2~).00 465.41 466.33 . 9 Ii 3.81 102,.20 466.32 468.23 • Ii 12 3.81 l~l.00 467.02 468.73 11 13 3.81 53 .00 467.43 469.30 13 14 3.81 24'.oo 468.33 469.30 14 15 J,81 1831 .00 472.79 474.76 15 16 3.81 26).00 473.59 475.08 . SA 17 4.73 32_1_13 464.48 466.76 . 17 18 4.73 24_).oo 465.12 466.76 18 19 4.73 1 Ll.oo 466.13 467.39 17 20 4.73 73 .13 466.66 469.42 . 20 21 4.73 24 i.oo 468.06 469.42 ~ 20 22 4.73 81 · .00 470.37 472.24 22 23 4.73 90\31 473.00 474.57 . 23 24 4.73 24...1.00 474.20 414.55 . 23 25 4.73 21131 473.94 41511 • 25 26 4.73 24_J.oo 475.14 475.43 . ZS 27 4.73 99 .00 476.26 477.66 . 23 28 4.73 112 .00 474.95 476.55 28 29 4.73 142 .00 477.46 479.07 29 30 4.73 28 .68 479.70 479.22 . 30 31 4.73 29 .00 480.98 479.25 30 32 0.81 293 '.00 479.86 49!.04 32 33 0.81 181 '.01 479.96 486.52 33 34 0.81 67 .00 480.02 480.60 34 35 0.81 20 '.00 480.05 480.60 . 33 36 0.81 150 .00 480.03 483.81 36 36A 0.81 150 .00 480.11 482.64 36A 37 0.81 89 .00 480.17 482.01 40A 40 1.79 16 .04 477.75 482.10 40 40B 1.79 16 .00 479.38 481.74 40 41 1.19 IOI .04 478.16 482.87 41 42 1.79 66 .00 478.45 478.99 42 43 l.79 34 .00 478.64 478.99 41 44 1.79 189 .04 485.10 490.12 44 45 1.19 30 .00 488.14 490.12 44 46 1.79 78 .04 485.SO 487.83 46 47 1.19 ,, .00 485.75 487 .83 46 48 l.79 35 .00 485.88 487.84 44 49 1.79 172 .00 489.13 491.8! 49 50 1.79 30 .00 4S9 .70 491.78 L JOB !'.,\.\IE: OB NUJ\IB£R: FROM CB TO FLOW CB tCFS' SA 4 OJ7 4 0.37 Outfall 5A 6.17 SA 3.42 6 2.75 7 2.75 7 2.75 9 2.15 9 10 2.75 9 11 2.75 11 12 2.15 11 13 2,75 13 14 2.75 14 15 2.75 15 16 2.75 SA 17 3.42 17 18 3.42 18 19 3.42 17 20 3.42 20 21 3.42 20 22 3.42 22 23 3.42 23 24 3A2 23 2S 3.42 25 26 3.42 25 27 3.42 23 28 3.42 28 29 3.42 29 30 3.42 30 31 3.42 30 32 0.59 32 33 0.59 33 34 0.59 34 3S 0.59 33 36 0.59 36 36A 0.59 36A 37 059 40A 40 40 40B 128 40 41 1.28 41 42 42 43 1.28 41 44 1.28 44 4S 1.28 44 46 J.28 46 47 J.'.!8 46 48 128 44 49 1.28 49 so 1.28 .. ·-:-:-:,=:11 It PIPEbN LENGj (FEET HEADWATER ~:LEVATION ,oo ~00 . •.09 9 •.03 •.II 2' •.00 10' •.II s, ,,oo •.00 ,, ·.07 24 11'·00 •,00 731 •.07 241 •.00 811 90',00 r.16 241 •.oo 211 '.16 241 1.00 991 ll2 1 142 1·00 28 00 JS 29 .00 293 181 .00 .00 67 20 .00 .00 150 150 .00 89 .00 •.00 16 16 1.00 IOI I 1,0? 66 I 34 !.00 1.00 189 1.02 30 1.00 78 ).02 22 1,00 35 l 1.0-0 \72 I 30 J.00 .00 {FEET) RIM EL 458.67 462.00 458.68 459.30 458.64 463.41 460.52 465.56 4o0.77 463.15 461.23 463.15 461.65 46336 463.36 466.16 464.12 466.33 465.88 468.23 466.24 468.73 466.88 469.30 467.34 469.30 472.53 474.76 47295 475.08 464.36 466.76 464.69 466.76 4(,5.24 467.39 466.68 469.42 467 .39 469.42 469.93 472.24 472.41 474.57 473.04 474.55 473.01 475.22 473.64 475.43 475.60 477.66 473.88 476.55 475.35 479.07 476.52 47912 477 .68 479.25 476.77 491.04 477 .67 486.52 478.02 480.60 478.21 480.60 478.71 483.81 479.46 482.64 479.92 482.01 477.69 482.10 479.32 481.74 477.90 482.87 478.04 478.99 478.14 478.99 485.06 490.12 488.08 490.12 485.45 487.83 485.69 487.83 485.82 487 .84 489.06 49l.8\ 489.64 491.78 Flow Frequency Analysis Time Series File:dwestlS.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.619 6 8/27/01 18:00 0.432 8 9/17/02 17:45 1. 28 2 12/08/02 17:15 0.499 7 8/23/04 14:30 0.689 5 11/17 /04 5:00 0. 726 4 10/27/05 10:45 0.857 3 10/25/06 22:45 1. 79 1 1/09/08 6:30 Computed Peaks -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period l. 79 1 100.00 0.990 1. 28 2 25.00 0.960 0.857 3 10.00 0.900 0. 726 4 5.00 0.800 0.689 5 3.00 0.667 0.619 6 2.00 0.500 0 .499 7 1. 30 0.231 0.432 8 1.10 0.091 1. 62 50.00 0.980 Flow Frequency Analysis Time Series File:deastl5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 3.18 6 8/27/01 18:00 2.22 8 9/17/02 17:45 6.52 2 12/08/02 17:15 2.57 7 8/23/04 14 :30 3.51 5 10/28/04 16:00 3.71 4 10/27/05 10:45 4.40 3 10/25/06 22:45 9.03 1 1/09/08 6:30 Computed Peaks -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 9.03 1 100.00 0.990 6.52 2 25.00 0.960 4.40 3 10.00 0.900 3.71 4 5.00 0.800 3.51 5 3.00 0.667 3.18 6 2.00 0.500 2.57 7 1. 30 0.231 2.22 8 1.10 0.091 8.19 50.00 0.980 Flow Frequency Analysis Time Series File:upeastlS.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.024 2 2/09/01 17:15 0.007 7 1/06/02 2:30 0.017 4 3/06/03 18:30 0.001 8 3/08/04 22:45 0. Oll 6 1/05/05 7: 30 0.018 3 1/18/06 20:15 0.015 5 11/24/06 4:15 0.039 1 1/09/08 9:30 Computed Peaks -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 0.039 1 100.00 0.990 0.024 2 25.00 0.960 0.018 3 10.00 0.900 0.017 4 5.00 0.800 0.015 5 3.00 0.667 0.011 6 2.00 0.500 0.007 7 1. 30 0.231 0.001 8 1.10 0.091 0.034 50.00 0.980 Flow Frequency Analysis Time Series File:postel5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks Rank Return Prob (CFS) (CFS) Period 3.18 6 8/27/01 18:00 9.06 1 100.00 0.990 2.22 8 9/17/02 17:45 6.54 2 25.00 0.960 6.54 2 12/08/02 17:15 4.40 3 10.00 0.900 2.57 7 8/23/04 14:30 3. 71 4 5.00 0.800 3.51 5 10/28/04 16:00 3.51 s 3.00 0.667 3.71 4 10/27/05 10:45 3.18 6 2.00 0.500 4.40 3 10/25/06 22:45 2.57 7 1. 30 0.231 9.06 1 1/09/08 6:30 2.22 8 1.10 0.091 Computed Peaks 8.22 50.00 0.980 Flow Frequency Analysis Time Series File: wout. tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak --Peaks --Rank Return (CFS) (CFS) (ft) Period 0.120 2 2/09/01 20:00 0.222 7.42 1 100.00 0.032 7 12/28/01 18,00 0.120 6.54 2 25.00 0.086 5 3/06/03 22:00 0.107 5.87 3 10.00 0.030 8 8/26/04 7,00 0.087 5.07 4 5.00 0.057 6 1/05/05 15:00 0.086 5.01 5 3.00 0.087 4 1/18/06 23,00 0.057 3.91 6 2.00 0.107 3 11/24/06 7:00 0.032 3.29 7 1. 30 0.222 1 1/09/08 11 :00 0.030 2. 77 8 1.10 Computed Peaks 0.188 7.41 50.00 0 6~, L00Q_(Q_u.:: ~,103--t (o.:A--_4,7.(pf I ou L~( 1_;0 ':) c_\.,Lu :c-4, 1. 06 -\-, .4;1..= 4;, '6 .. X) Prob 0.990 0. 960 0.900 0.800 0.667 0.500 0.231 0. 091 0.980 Flow Frequency Analysis Time series File:eout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.673 2 2/09/01 20:00 0.164 7 12/29/01 10:00 0.505 4 3/06/03 22:00 0.148 8 8/26/04 7:00 0.177 6 1/08/05 2:00 0.408 5 1/18/06 23: 00 0.572 3 11/24/06 8:00 2.20 1 1/09/08 10:00 computed Peaks EOUT. PKS -----Flow Frequency Analysis------- --Peaks --Rank Return Prob (CFS) (ft) Period 2.20 7.11 1 100.00 0.990 0.673 6.69 2 25 .oo 0.960 0. 572 6.11 3 10.00 0.900 0. 505 5.81 4 5 .00 0.800 0.408 5.47 5 3.00 0.667 0.177 4.55 6 2.00 0. 500 0.164 3.87 7 1. 30 0.231 0.148 3.19 8 1.10 0.091 1.69 7.06 50.00 0.980 25-year water surface= 451.0 + 6.69 = 457.69 100-year water surface= 451.0 + 7.11 = 458.11 Page 1 OFF-SITE DRAINAGE SYSTEM Some culverts along SE 136th Street and l 60'h Avenue SE are to be relocated, added, and/or replaced. Also, due to proposed shoulder construction along 160th Avenue SE, the existing ditch along the west side of the road will be relocated behind the proposed shoulder. A tightlined storm line will bypass stormwater from the l 60'h roadside ditch and areas upstream of the project site down to the a discharge point near the southeast comer of the proposed Nichols development. Storm water from the Evendell plat' s stormwater pond will enter this system at the project site's southeast comer, upstream of the system's discharge point. The off-site drainage system was sized to convey the 25- year and 100-year flows calculated in the Level 3 Downstream Drainage Analysis by Haozous Engineering, dated August 26, 2002. See Section 6 of this report for a copy of the report. The King County Backwater (KCBW) program was used to analyze the capacity of this entire system along 160'\ including the tightlined portion, the open channel and the culvert under 136th Street. The output from the KCBW analysis follows at the end of this section. In order to determine a tailwater depth at the conveyance system's discharge point, the existing ditch downstream of this point was analyzed to determine the flow depth that would be realized to convey the 100-year storm event flows. The flows provided in the Haozous report at node #117 were used to analyze this system. The discharge from the Evendell detention pond will match the existing site discharge for the 25-year event, but will exceed the existing by 1.6 cfs for the 100-year event. So, the total flow at the downstream discharge point will be: Q25 = 18.3 cfs and Qioo = (22.5 + 1.6) = 24.1 cfs. In Section 3 of their report, Table 1 -Description of Downstream Conveyance System , describes the ditch in this area as having a 2' wide bottom, 1.5' of depth, 3:1 sideslopes and a 2% slope. A Manning's 'n' value of0.050 was used to represent a "constructed channel with a clean bottom and brush on the sides". As shown on the attached spreadsheet titled J 6dhDitch Analysis -Existing@ Outfall, the flow depth in the ditch would be 1.26 feet and the velocity 3.4 fps, when conveying the 100-year storm event flow of 25 cfs. The outfall has an invert elevation of 444.86, so the tailwater elevation was determined to be 446.12, which was used for all of the KCBW analyses, both for the 25-year and 100-year events. Flows input into the KCBW program for each segment of the conveyance system were adjusted to account for the stormwater contributed to the system by runoff from 160th and from the Evendell pond discharge. The flows used were as follows: Downstrean1 of Outfall 1 B: CB 1 to Outfall lB: Input to CB 1 from Pond: Input to CB 1 from 160'h: CB IA to CB 1 and upstream: llis {cfs) 18.3 17.6 0.7 0.4 16.5 Q100 (cfs) 24.1 23.0 2.6 0.5 19.9 The same flow values calculated for the run from CB I A to CB I were used for the rest of the system upstream of CB I A, rather than attempting to approximate the gradually increasing flows that will enter the open channel due to runoff from 160'\ As shown on the KCBW program output that follows this report, the system of pipes, open channel and culverts proposed for the project's frontage on 160 1h Avenue SE will have adequate capacity to convey the design storm events. Additionally, the velocity in the open channel portion of this system is shown to be Jess than 5 fys, so grass lining is appropriate for this channel. ,,.··, .,f 1··.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·. ·.· .•. ·.· .·. ·.·.·.·.·.·.· .•. ·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.· ·.·.·.·.·.· .•. ·.·.· ·.·.· ·.·.· .·.·.·.· .·.· .. ·.·.·.·.·.·.·.· .. ·.·.·.· .. 1. ·•1··60· ·T· ·H· .... D. ·1'T'n·H· ... A. ·N·A·· ·L··•'7 S·1·s·>•·• ·EX·I·s=1G· ··>@· · ·· .. o· T·T'T'F·A· >t···t·· ::>::.-:./:.>..:_ /_:::..:.:J:Y:._:/\: .·: :. .. :.:.:-::_·:::J::: :· .. :.: :· .. :::::-::: .. .::,:.:-:-:.: .· .. :~:~{:'!:..·:·.::::: .· :::.:·:.};.;;i_:}.::·.-< :-..:-.·:.:.:·: DITCH DATA: BOTTOM WIDTH (FT)= LEFT SIDE SLOPE (L:1) RIGHT SIDE SLOPE (R:l BOTTOM SLOPE (FT/FT MANNING'S n = FLOW FLOW DEPTH (FEET) 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00 1.10 1.20 1.24 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 AREA (SQ l<'T) 0.0000 0.1075 0.2300 0.3675 0.5200 0.6875 0.8700 1.0675 1.2800 1.5075 1.7500 2.0075 2.2800 2.5675 2.8700 3.1875 3.5200 3.8675 4.2300 4.6075 5.0000 5.8055 6.7200 7.1230 7.6700 8.6800 9.7500 10.8800 12.0700 13.3200 14.6300 16.0000 2.00 JOB NAME: EVENDELL 3.00 JOB#: 04009 3.00 OPERATOR: S.R.B. 0.0200 DATE: 10/9/2004 0.050 WETTED PERIMETER (FEET) 0.0000 2.3162 2.6325 2.9487 3.2649 3.5811 3.8974 4.2136 4.5298 4.8460 5.1623 5.4785 5.7947 6.1110 6.4272 6.7434 7.0596 7.3759 7.6921 8.0083 8.3246 8.9390 9.5895 9.8627 10.2219 10.8544 11.4868 12.1193 12.7517 13.3842 14.0167 14.6491 HYDRAULIC RADIUS (FEET) 0.0000 0.0464 0.0874 0.1246 0.1593 0.1920 0.2232 0.2533 0.2826 0.3111 0.3390 0.3664 0.3935 0.4201 0.4465 0.4727 0.4986 0.5243 0.5499 0.5753 0.6006 0.6495 0.7008 0.7222 0.7503 0.7997 0.8488 0.8977 0.9465 0.9952 1.0438 1.0922 DITCH CAPACITY (CFS) 0.000 0.058 0.190 0.385 0.642 0.962 1.346 1.796 2.317 2.909 3.576 4.321 5.146 6.054 7.047 8.129 9.303 10.570 11.933 13.396 14.960 18.300 22.283 24.100 26.620 31.431 36.737 42.556 48.906 55.805 63.271 71.322 FLOW VELOCITY (FPS) 0.000 0.543 0.828 1.049 1.235 1.399 1.547 1.683 1.810 1.930 2.043 2.152 2.257 2.358 2.455 2.550 2.643 2.733 2.821 2.907 2.992 3.152 3.316 3.383 3.471 3.621 3.768 3.911 4.052 4.190 4.325 4.458 Plat of Evendell -KCBW Program Output BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:04009bl.bwp Surcharge condition at intermediate junctions Tailwater Elevation:446.12 feet Discharge Range:17.6 to 23. Step of 5.4 [cfs] Overflow Elevation:461. feet Weir:NONE Upstream Velocity:3.4 feet/sec PIPE NO. 1: 59 LF -24"CP @ 1.00% OVERFLOW-EL: 449.91 BEND: OUTLET: 444.86 INLET: 445.45 INTYP: 5 JUNC NO. 1: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.00 Q (CFS) HW (FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 17.60 23.00 2.09 2.65 447.54 * 0.012 1.52 1.26 1.26 1.26 1.52 ***** 448.10 * 0.012 1.71 1.54 1.26 1.54 1.71 ***** 2.09 2.65 PIPE NO. 2: JUNC NO. 2: 239 LF -24"CP @ OVERFLOW-EL: 454.77 1. 80% BEND: OUTLET: 445.45 INLET: 449.75 INTYP: 5 0 DEG DIA/WIDTH: 6.0 Q-RATIO: 0.18 Q (CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 17.60 23.00 2.26 2.95 452.01 * 0.012 1.52 1.05 2.09 2.09 1.52 ***** 452.70 * 0.012 1.71 1.24 2.65 2.65 1.71 ***** 2.26 2.95 PIPE NO. 3: 291 LF -24"CP @ 2.84% OUTLET: 449.75 INLET: 458.00 INTYP: 5 Q (CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* 14.92 19.49 2.04 2.66 460.04 460.66 * 0.012 * 0.012 1. 40 1.59 0.84 0.97 2.26 2.95 2.26 2.95 1.40 ***** 1.59 ***** 2.04 2.66 BACKWATER COMPUTER PROGRAM FOR OPEN CHANNELS Channel Data Filename,04009b3.bwc Tailwater from HW/TW File,04009bl.bwt Discharge Range,16.5 to 19.9 Step of 3.4 [cfs] STATION 0.00, INVERT= 461.00 FT EC=l. 15 Q-RATI0=0. 00 CROSS-SECTION DATA, DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0.050 * * RIGHT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0.050 Q(CFS) Yl (FT) WS ELEV. * YC-IN YN-IN Q-TW TW-HT N-Yl A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 1.17 **************** 19.90 1.26 462.17 * 1.17 1.15 16.50 RANGE EXCEEDED IN HW/TW FILE - 462.26 * 1.26 1.23 19.90 0.00 0.050 4 .11 7.40 4.02 DATA EXTRAPOLATED************* 0.00 0.050 4.76 7.97 4.18 ****REACH NO. 1: STATION 110.00, CROSS-SECTION DATA, LENGTH= 110.00 FT INVERT= 466.00 FT AVG.GRADE= 4.55% **** EC=l.15 Q-RATI0=0. 00 DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) N-FACTOR 0.050 * * RIGHT(FT) STAGE(FT) N-FACTOR 0.050 4.50 1.50 4.50 1.50 Q(CFS) Yl (FT) WS ELEV. * YC-IN YN-IN YC-OT YN-OT N-Yl A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 19.90 1.16 1.24 ****REACH NO. 2: STATION 203.00, CROSS-SECTION DATA, 467.16 * 1.17 1.16 1.17 1.15 0.050 467.24 * 1.26 1.24 1.26 1.23 0.050 4.04 4.61 LENGTH= 93.00 FT INVERT= 470.00 FT AVG.GRADE= 4.30% **** EC=l.15 Q-RATI0=0.00 7.34 4.09 7.84 4.31 DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0.050 * * RIGHT(FT) STAGE(FT) 4.50 1.50 Q (CFS) Yl (FT) WS ELEV. * YC-IN YN-IN YC-OT YN-OT N-Yl N-FACTOR 0.050 A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 19.90 1.16 1.24 471.16 4 71. 24 * * 1. 17 1.15 1.26 1.23 1.17 1. 26 1.16 0.050 1.24 0.050 4.04 4.61 7.34 7.84 4.09 4.31 ****REACH NO. 3: STATION 290.00: CROSS-SECTION DATA: LENGTH= 87.00 FT INVERT= 474.00 FT AVG.GRADE= 4.60% **** EC=l.15 Q-RATI0=0.00 DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0.050 * * RIGHT(FT) STAGE(FT) 4.50 1.50 Q(CFS) Yl (FT) WS ELEV. * YC-IN YN-IN YC-OT YN-OT N-Yl N-FACTOR 0.050 A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 19.90 1.17 1.26 ****REACH NO. 4: STATION 400.00: CROSS-SECTION DATA: 475.17 * 475.26 * 1.17 1.26 LENGTH= 110.00 FT INVERT= 478.00 FT 1. 20 1.28 1.17 1.26 1. 15 0. 050 1.23 0.050 4.11 4.76 AVG.GRADE= 3.64% **** EC=l.15 Q-RATI0=0. 00 7.40 7.97 4.02 4.18 DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0.050 * * RIGHT(FT) STAGE(FT) 4.50 1.50 Q(CFS) Yl (FT) WS ELEV. * YC-IN YN-IN YC-OT YN-OT N-Yl N-FACTOR 0.050 A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 19.90 1. 28 1. 38 479.28 * 1.17 1.28 1.17 1.20 0.050 479.38 * 1.26 1.38 1.26 1.28 0.050 4.92 5.71 8.10 3.36 8.73 3.48 ****REACH NO. 5: LENGTH= 30.00 FT INVERT= 478.75 FT AVG.GRADE= 2.50% **** STATION 430.00: EC=l.15 Q-RATI0=0.00 CROSS-SECTION DATA: DIST/STAGE IS MEASURED FROM INVERT; N-FAC IS MEASURED BETWEEN STAGES LEFT(FT) STAGE(FT) 4.50 1.50 N-FACTOR 0:050 * * RIGHT(FT) STAGE(FT) 4.50 1.50 Q (CFS) Yl (FT) WS ELEV. * YC-IN YN-IN YC-OT YN-OT N-Yl N-FACTOR 0.050 A-Yl WP-Yl V-Yl ******************************************************************************* 16.50 19.90 1. 28 1. 38 480.03 480.13 ROUTING DATA RESULTS: STAGE(FT) DISCHARGE(CFS) 0.00 1.17 1. 26 0.00 16.50 19.90 ROUTING DATA RESULTS: STAGE(FT) DISCHARGE(CFS) 0.00 0.00 1.17 16.50 1.26 19.90 * 1.17 0.00 * 1.26 0.00 STORAGE(CU-FT) 0.0 1821.2 2100.1 STORAGE(CU-FT) 0.0 1821. 2 2100.1 File Opened for Writing:04009b3.bwt Save results to HW/TW file:04009b3.bwt File Opened for Writing:04009b3.RS1 Save results to Routing file:04009b3.RS1 1.17 1.28 0.050 1.26 1.38 0.050 PERM-AREA(SQ-FT) 0.0 3228.9 3466.9 PERM-AREA (SQ-FT) 0.0 3228.9 3466.9 4.92 5. 71 8.10 3.36 8.73 3.48 BACKWATER PROGRAM FOR ROUND/ARCH CULVERTS Tailwater from HW/TW File:04009b3.bwt Discharge Range:16.5 to 19.9 Step of 3.4 [cfs] Overflow Elevation:483.5 feet Weir:NONE Upstream Velocity:4. feet/sec CULV NO. l: 94 LF -24"CP @ 0.80% OUTLET: 478.75 INLET: 479.50 INTYP: 3 TW DATA ADJUSTED BASED ON CROSS-SECTIONAL AREA Q-TOT(CFS) TW(FT) TW-ELEV(FT) Q-ADJ(CFS) AREA(SQ-FT) ******************************************************************** Q(CFS) 0.00 16.50 19.90 HW (FT) 0.00 1. 28 1. 38 478.75 480.03 480.13 HW ELEV. * N-FAC DC 0.00 16.50 19.90 DN TW 0.00 2.12 2.31 DO DE HWO HWI ******************************************************************************* 16.50 19.90 2.35 3.12 481.85 * 0.012 482.62 * 0.012 1.47 1. 61 1. 30 1. so 1.28 1. 38 1.30 1.50 1. 47 1.61 ***** ***** 2.35 3.12 6. SPECIAL REPORTS AND STUDIES: Included in this section are the postmaster approval; the Preliminary T.l.R. by Haozous Engineering., dated June 15, 200 I; the Level 3 Downstream Drainage Analysis by Haozous Engineering., dated August 26, 2002; the Preliminary Geotechnical Engineering Report by US Land Development Associates, dated November 16, 2001; the Wetland Report by Habitat Technologies, dated October 28, 2002 (addendum) and May 15, 2001; the vault structural plans as prepared by Miles Consulting, dated May 2004, a letter from Bruce and Joyce Osgoodby (property owners on north side of SE 1361h Street), dated July 14'\ 2004, allowing permission to enter the property for installation of rockery and regrading of existing driveway; a letter from Bruce and Joyce Osgoodby, dated September 27'\ 2004, allowing permission to enter the property for reconstruction of keystone wall; transfer of density credit documentation; copy of Boundary Line Adjustment; copy of recorded drainage easement; response to Hearing Examiner's Condition #19-a; Technical Memorandum addressing Retaining Wall along north edge of SE 1361h St., prepared by Associated Earth Sciences, Inc., dated November 3, 2004; Pedestrian Path approval letter from Issaquah School District, dated November 7, 2004. '" ll. --s '" I\J 2 u -r ,'.::j z: 1•.· ;:, '-" ~-'. ~: U. •;! '" .. , t,) l'-1 '" "' ,, .... • • • ' ' ' \ .. ' ' ' ' ' • ' ' ' • \ \ ' L-.--~C'> :.-, ••• I',,..,..., ----=-=-·=-----------r----= ~ ., 'I ,. .. .... -' '~ . ii ~ ~ 1 i I • R ~ij) -. . ~ • ·-- • e • .. • i I ~ '31\\il-:P.L. r--------------- t,. d t,02 'ON JNI N~I53CT 3~0) WdSE:T t,002'S ·~dtJ • i Even.dell Plat Preliminary Technical Information Report Submitted to: King County DDES 900 Oakesdale Avenue S.W. Renton, WA 98055 Prepared by: Haozous Engineering, P.S. 14816 SE 116th Street Renton, WA 98059 Tel. ( 425) 235-2707 Fax ( 425) .254-0579 June 15, 2001 @fj§!W&Sf,<,·S§lti&"3'1@i&¥&¥&:a: i· 't #5 's1ki!@ g,, 0 ,; 5 ii. t''? TABLE OF CONTENTS 1. Project Overview ...................................................... : ........................................................ 1-1 2. Conditions and Requirements Summary ........................................................................... 2-1 3. Offsite Analysis ................................................................................................................. 3-1 4. Flow Control and Water Quality Facility Analysis and Design ....................................... .4-1 5. Conveyance System Analysis and Design ......................................................................... 5-1 6. Special Reports and Studies .............................................................................................. 6-1 7. Other Permits ................................................................................. : .................................. 7-1 8. ESC Analysis and Design ................................................................................................. 8-1 9. Bond Quantities, Facility Summaries, and Declaration of Covenant.. .............................. 9-1 10. Operations and Maintenance Manual.. .......................................................................... 10-1 11. References ..................................................................................................................... 11-l LIST OF TABLES Table 1. Description of Downstream Conveyance System ................................................... 3-5 Table 2. Existing and Developed Site Basin Conditions ..................................................... .4-2 Table 3. Summary of Performance Standards ....................................................................... 4-3 Table 4. Wet Pond Sizing Calculations .............................................................................. .4-11 Table 5. Summary of Special Reports and Studies ............................................................... 6-1 Table 6. Summary of Other Permits Required ....................... : ........................................ : ..... 7-1 Table 7. Summary of Maintenance Requirements for Stormwater Facilities ..................... 10-1 ".~ '· ) b D I D b LIST OF FIGURES Figure 1. TIR Worksheet.. ........................................................................... : ......................... 1-2 Figure 2. Vicinity Map .......................................................................................................... 1-5 Figure 3. Drainage Basins ..................................................................................................... 1-6 Figure 4. Soils Map ............................................................................................................... 1-7 Figure 5. Downstream Conveyance System .......................................................................... 3-4 Figure 6. Stormwater System Design .................................................................................... 4-6 Figure 7 A. Flow Duration Curves for RID -East Basin ...................................................... .4-7 Figure 7B. Flow Duration Curves for RID -West Basin ...................................................... 4-9 Figure 8. Erosion and Sedimentation Control Plan ............................................................... 8-2 Figure 9. Site Improvement Bond Quantity Worksheet ........................................................ 9-2 Figure 10. Flow Control and Water Quality Facility Summary ............................................ 9-3 APPENDICES Appendix A. Downstream System Appendix B. Stormwater RID System Design Appendix C. Conveyance Calculations Appendix D. Hydrologic Model Documentation ;; 1. Project Oierview Project Description A swnmary of the Evendell Plat project is provided in the TIR Worksheet (Figure I). This preliminary technical information report (TIR) addresses the design of stormwater facilities and the offsite drainage analysis for the Evendell Plat project. The Evendell Plat project is a proposed residential development located within the Renton Highlands area of unincorporated King County (Figure 2). The proposal for development includes building 75 single-family dwellings on approximately 12 acres. Road improvements along SE 136th Street are also proposed. The proposed site plan is provided in Figure 6 of Section 4. Site Description The site is located within the Orting Hills subbasin of the Cedar River watershed (King County Department ofNatural Resources, 1999). The site consists of two basins. The topography of the east basin generally slopes from the northwest to the southeast (Figure 3). The topography of the west basin generally slopes from the east to the west. The elevation of the site ranges from about 494 feet (NAVD 88) in the north portion of the site to 456 feet in the southeast comer. The project is located east of 156th Avenue SE and is bordered by SE 136th Street on the north and by 1601h Avenue SE on the east. Cover types on the site include a single-family residence, pasture, and forest (Photo I in Appendix A. I). A Class 2 wetland has been identified in the northeast portion of the site. Based on King County Soil Survey (U.S. Department of Agriculture, 1973) the site consists of Alderwood soils (Figure 4). Drainage from an approximately 0.94-acre tributary subbasin adjacent to the west boundary of the easterly basin sheet flows onto the site (Figure 3). The easterly basin drains to a conveyance system along 1601h Avenue SE. The westerly basin drains to a conveyance system along 156th Avenue SE. Both downstream drainage courses eventually discharge to an unclassified tributary of the Cedar River (King County Department of Parks, Planning, and Resources, 1990). Stormwater Design Under developed conditions, stormwater from the site and offsite road improvements will be collected and treated onsite to basic water quality standards. A combined wetpond/detention pond will be used to manage runoff in the easterly basin. A small wetvault will provide water quality treatment to a portion of SE 136th Street that bypasses the stormwater facility in the east basin. A vault followed by a biofiltration swale will be used to manage runoff in the westerly basin. Level 2 RID standards are required by the King County Flow Application Maps and recommended by Lower Cedar River Basin and Nonpoint Action Plan. Natural discharge locations from the site will be maintained at the outlet of the proposed stormwater facilities. 1-1 Evenddl Pim Pn:liminary 71R-.Jure 2001 Figure 1. TIR Worksheet I TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project Owner: U.S. Land Development Associates, Inc. Address: Clo: Mike Romano Centurion Development Services · 22617 8th Dr. SE Bothell, WA 98021 Phone: (425) 486-2563 Project Engineer: Ed McCarthy, P.E. Company: Haozous Engineering, P.S. Address/Phone: 14816 SE 116th Street Renton, WA 98059 /425) 235-2707 Part 3 TYPE OF PERMIT APPLICATION jg] Residential jg] Grading Part 2 PROJECT LOCATION AND DESCRIPTION Project Name: Evendell Plat Location: West of 160th Avenue SE and bordered by SE 136th Street on the north. Township: 23N Range: 5E Section: 14 Description: The proposal for development includes building 75 single-family dwellings on approximately 12 acres. Part 4 OTHER REVIEWS AND PERMITS D DFWHPA ~ Wetlands ~ National .Pollutant Discharge Elimination System (NPDES) Stormwater Permit ~ Forest Practices Class IV General Part 5 SITE COMMUNITY AND DRAINAGE BASIN Community: King County Drainaqe Basin: Lower Cedar River Watershed; Ortina Hills subbasin Part 6 SITE CHARACTERISTICS D River: NIA D Stream: N/A D Critical Stream Reach: N/A D Depressions/Swales: N/A D Lake: NIA D Steep Slopes: N/A D Floodplain: N/A ~ Wetlands: Onsite Class 2 Wetland D Seeps/Springs: NIA D High Groundwater Table: N/A D Groundwater Recharge: N/A 1-2 1. Part 7 SOILS Soil Type Alderwood Slopes Moderate Part 8 DEVELOPMENT LIMITATIONS REFERENCE Ch 6 Water Quality Requirements Ch 5 -Flow Control Part 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION . ~ Sedimentation Facilities ~ Stabilized Construction Entrance ~ Perimeter Runoff Control ~ Cover Practices ~ Construction Sequence Part 10 SURFACE WATER SYSTEM Erosion Potential Erosive Velocities LIMITATION/SITE CONSTRAINT Onsite treatment -basic standards Level 2 R/D standards MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION ~ Stabilize Exposed Surface ~ Remove and Restore Temporary ESC Facilities ~ Clean and Remove All Silt and Debris ~ Ensure Operation of Permanent Facil.ities Basin Water Qualitv Treatment Detention East Wetoond/Wetvault Level 2 Pond West Biofiltration swale Level 2 Vault Facility Related Site Design Considerations: Reference Facility Design Consideration 1-3 I Part 11 STRUCTURAL ANALYSIS 00 Rockery> 4' High D Berms > 6': NIA Part 12 EASEMENTS/TRACTS D Drainage Easement: NIA D Access Easement: N/A D Native Growth Protection Easement ~ Sensitive areas 00 Stormwater tracts Part 13 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 attachments. To the best of my knowledge the information provided here is accurate. 1-4 \: \. . '"',, '\\\\:\\ \ la,_;_\ ' : 01 . .::; \. :\ \, \' . : ::, r ' 0 • • ·' g :······ .. ..--:. .... ~ SOURCE: USGS 7.5 x 15 Minute Series -Renton, Washington SCALE: 1 :25 000 TITLE Figure 2. Vicinity Map PAGE DA1la 1-6 01/03/01 ~:,:;,1:a:~?'.~': q ,. .~· 'C7' ~ SCIU ~ fttT 0 200 DATE NO. -~ -,r:::J" -C7 '··-,.I --"'1:7' -·- lfl' ..._ ._,., ._ -~ ,r -. ':"'.".,. -c- "' UI . :::, i:? :::J ~ 0 u D c::::'.J 111\ D . 1·.··:·i I., ~\\ ~LI J uJ 0~ -......,).. • • I· "'~- ~J ·r-.\., \.,1~0.L .)"~ I~ 1\...,.7f ~<"'5 iP..o [ [ '!/ [ ~ I_,"'·"' .• ,....,..,.,'<..., l ' I.I r RE\'1SION BY • )( [ [ ,.,r:;;-·· .. ( .t= _. ~ .IA • 0 ] -_e [ -A,.. (,,_, -Jr \ \.,w../'i... l r--, . ~ 6 ~~ ~ ">, l \ir"'r~N">. ·c j~ I l Uh, 2c \ "', d~ • ""-I ....,..,,., \ J } '\ [ [ [ r I,. I[ lp -\.../" -. ~~ Haozous Engineering CIVIL ENGINEERING EVENDELL PL.AT PROJECT NO. 1-4816 SE 116TH ST, RENTON, v/A 98059 -425-235-2707 ----·i--.. ·---............. -------------------. I I DCSIONED 11'1'1 '"" 1/08/01 SHEET Figure 3. Drainage Basins 1-6 EJ" DIIAMI &YI EJM --------- '"" 1/08/01 CX' 1. ) SCALE: 1 :24 000 1" = 2,000' TITl.E PAGE Figure 4. Soils Map DAlE 1-7 01J!l3/01 '· -···-.-~-~·J..,'"'" "'"' 2. Co11ditioiis anifRequiremtntsSummary . A summary of conditions and requirements for the project are presented in this section. The following is a summary of core and special requirements from the 1998 King County Surface Water Design Manual: Core Requirement 1: Discharge at the Natural Location The natural discharge locations from the site will be maintained at the outlets of the proposed stormwater facilities. · Core Requirement 2: Off-site Analysis A Level 1 downstream drainage analysis is presented in Section 3. Core Requirement 3: Runoff.Control . Level 2 RID standards are required for the site. Core Requirement 4: Conveyance System The onsite stormwater conveyance system and offsite improvements will be designed to convey the 25-year storm. Core Requirement 5: Erosion/S~di1Dentation Control Plan . ··,,-···: . Proposed erosion/sedimentation ci:mtrol pmced~es are described in Section 8. An erosion/sedimentation control plan (ES,CP) wiil be developed for the project during engineering design. · · · Core Requirement 6: Maintenanc~ a1,11l Op~ration The proposed systems for mana~{ng ~t~rmf~te; wiU be maintained and operated by King County. Recommended maintenance a~tiviJie~ are provided in Section I 0. Core Requirement 7: Bonds and J,,iabllio/ Bonds and liability requirements will be developed for the project during engineering design (Section 9). 2-1 Evendell Plat Preliminary VR-Jwie 2001 p ,. Core Requirement 8: Water Quality As described in Section 5.E, basic water quality standards apply to the site. A basic wetpond will provide water quality treatment for stormwater collected from the site's east basin. A biofiltration swale will provide water quality treatment for stormwater collected from the site's west basin. Alternatively, a wetvault may be used to treat stormwater collected from the site's west basin. A small wetvault will provide water quality treatment for stormwater collected a portion of road improvements along SE 136th Street. Special Requirement 1: Other Adopted Area-Specific Requirements The site is within the Cedar River Basin. Basin-wide requirements have been recommended by the Lower Cedar River Basin and Nonpoint Action Plan that apply to the site. These requirements are covered by the 1998 King County Surface Water Design Manual Applications Maps. Special Requirement 2: Delineation of 100-Year Floodplain The site is not within a 100-year floodplain. Special Requirement 3: Flood Protection Facilities The project does not contain nor is it adjacent to a flood protection facility. Special Requirement 4: Source Controls Source controls are not proposed for the development. Special Requirement 5: Oil Control The proposed development does not meet the definition of a high-use site requiring oil control. 2-2 Evoufell Plat Prelimu,ary T1R-June 2001 '. L. 3. Offsite Analysis The site and project area are in two separate basins. The majority of the site is in the easterly basin. Topography in this basin slopes primarily from the northwest to the southeast towards 1601h Avenue SE. A smaller portion of the site flows the west. This includes the northwest and southwest corners of the site, as well as a portion of proposed road improvements along SE 136th Street. These portions of the site flow to the west towards 156th Avenue SE. A downstream drainage analysis for the site, including drainage routes along both 160th Avenue SE and 1561h A venue SE, is presented in this section. The drainage courses from the site were assessed on O 1/05/01. Moderate rainfall occurred during the morning prior to the site visit. The downstream conveyance system is described below and illustrated in Figure 5. Further descriptions of downstream structures are summarized in Table 1. Upstream Drainage Drainage from an approximately 0.94-acre tributary subbasin adjacent to the site's western boundary sheet flows onto the site's easterly basin (Figure 3). Runoff from areas north of the site is collected in the roadside ditch along 158th Avenue SE (Location 2 in Figure 5). Runoff collected in the ditch on the west side of I58'h Avenue SE is conveyed to the east through a 12- inch diameter culvert (Location 1) under the cul-de-sac of 158th Avenue SE. The culvert at Location I also conveys drainage from a section of ditch along the north side of SE 136'h Street (Location 30). The 12-inch diameter culvert discharges to an earth-lined ditch on the site's north boundary (Location 3, Photo 3 in Appendix A. I). Segments of the ditch show signs of minor erosion. The northerly ditch also collects runoff from the roadside ditch on the east side of 158th A venue SE and from properties to the north. The vegetation and dimensions of the northerly ditch change as it proceeds from west to east (Locations 4 and 5). At the northeast corner of the site, a ditch on the west side of 160th Avenue SE joins the system. The system subsequently jogs around a utility box (Location 6). The ditch continues along the east boundary of the site (Location 7). No scouring or erosion was observed in the grass-lined ditch along this segment. The road embankment on the west side of 160th A venue SE is steep, but stable. A side channel from the onsite wetland merges with the roadside ditch at Location 8. (Photo 4 in Appendix A. I). A small amount of flow was observed exiting the wetland at the time of the site visit. The ditch continues along the east boundary of the site to the site's southeast corner. Downstream Drainage Course -1601 h Avenue SE Upon leaving the site's southeast corner, the grass-lined ditch continues in a southerly direction through 12-inch diameter driveway culverts (Locations 10 through 13, Photo 5 in Appendix A.I). At a distance of about 660 feet from the site, a 12-inch diameter concrete pipe conveys drainage to the east side of 160th A venue SE (Location 14 ). The site comprises approximately 17 percent of the tributary basin area at this point in the drainage system. Drainage is then conveyed through a 24-inch diameter CMP driveway culvert with a crimped end (Location 15). From Location 15, drainage is conveyed through a short section of ditch with accumulated sediment 3-1 Evmddl 1'1111 Preliminary 11R-June 2001 (Location 16). At a distance of about 860 feet from the site, drainage flows through an 18-inch diameter pipe at the residence of 14028 -1601h Avenue SE (Location 17). A past drainage problem (Drainage Complaint No. 97-0423) was reported at this location. The complaint was not available but was related to overflow from the roadside ditch (Appendix A.2). The 18-inch diameter pipe discharges to an earth-lined section of ditch (Location 18). Minor erosion was observed at the outlet of the 18-inch diameter pipe. At a distance of about 1,000 feet from the site, drainage flows away 160th A venue SE to the east, among trees on a forested parcel (Location 19). The channel is somewhat flat and braided after leaving the roadside ditch and passes through a ponded area (Location 20), The channel then becomes more well-defined (Location 21) and enters a 12-inch diameter pipe (Location 22) located near a horse corral. Drainage is then conveyed through a 12-inch diameter driveway culvert (Location 23) and then to an open channel. The open channel flows along the north boundary of residential lots that are along SE 142"d Place. A segment of the channel has been reinforced with concrete blocks (Location 24 ). Drainage then enters an 18-inch diameter pipe that has a trash rack and concrete headwall inlet (Location 25). At Location 26, the channel turns to the south and has significant . bank erosion at the bend. The site comprises approximately 9 percent of the tributary basin area at this point in the drainage system. The channel then flows down the hill (Location 27) towards SE 144th Street. A past drainage problem (Drainage Complaint No. 97-0206) was reported at Location 25 (Appendix A.2). The resident at 16046 -SE 142"d Place has had problems from runoff in the channel along his property .. The 18-inch diameter pipe has likely been installed since the complaint was filed to reduce groundwater seepage from the ditch that was apparently compromising the performance of the homeowner's onsite sewage treatment system. The homeowner also stated in the complaint that he maintains the ditch long the north and east boundaries of his property by removing accumulations of debris and sediment. King County investigated the problem for the Neighborhood Drainage Assistance Program. Downstream Drainage Course -1561h Avenue SE A break in grade approximately 250 feet west of the intersection of SE 136th Street and! 58th A venue SE divides surface water flow to the east and west. From the grade break, drainage flows west along a shallow grass-lined ditch along the north side of SE 136th Street (Location 31 ). Road improvements end about 375 feet west of 1581h Avenue SE, at which point the roadside ditch discharges to a grassy area in the road right-of-way (Location 31 ). There is no distinct flow path in the road right-of-way and drainage likely reaches the ditch along 1561 h Avenue SE by sheet or shallow flow. At the intersection of SE 136th Street (Location 33, Photo 6 in Appendix A.I), the earth-lined ditch along 156th Avenue SE flows to the south. At a distance of about 150 feet south of SE 136th Street, drainage enters a series of Type 1 catch basins connected by segments of ditch and 12-inch diameter pipe (Locations 34 through 52). No signs of capacity problems were observed along the drainage route at these locations. At Locations 35 and 37, leaves and other debris have accumulated, presenting the potential for plugging downstream sections of pipe. 3-2 Evenddl Plat Preliminary TJR-June 2001 l. At Locations 42 and 43, drainage from SE 1381h Place enters the conveyance system. Runoff from the southeast comer of the site sheet flows towards the backyards of homes at the end of SE 138th Place. Runoff from this area of the site eventually drains to the conveyance system along SE 138th Place. A past drainage problem (Drainage Complaint No. 97-0107) was reported by the resident at 15641 SE 138th Place (Appendix A.2). Based on King County's record, the complaint was related to a change in drainage pattern due to a broken culvert at the cul-de-sac (Appendix A.2). AtLocations 46 and 47, drainage from SE 139th Place enters the conveyance system. Downstream from Location 52, a grass-lined ditch conveys drainage to the south along a pasture (Location 53). At the lower end of the pasture (Location 54) the ditch flattens and it appears that high flow rates could flow onto a portion of the pasture. At Location 55, drainage enters a 12- inch diameter pipe. A past drainage problem (Drainage Complaint No. 97-0318) was reported at Location 55 by the resident at 14038 561h Avenue SE (Appendix A.2). The complaint is a claim and was not available from King County. Based on King County's record, the complaint was related to flooding due to a plugged culvert (Appendix A.2). Downstream Drainage Complaints Drainage complaints along the downstream system were investigated at King County Water and Land Resource Division. Drainage Complaint Nos. 97-0423, 97-0206, 95-0107, and 97-0318 are along the drainage route and are described in the narrative above. A map showing the locations of residents that filed drainage complaints is provided in Appendix A.2. Copies ofregistered drainage complaints are listed in Appendix A.2. A summary of the drainage complaints is provided in Table A.I of Appendix A.2. 3-3 Evende/1 Plat Preliminary T1R-June 2001 ·=~' I, II e.. ,~ I•® .. lll ,··-,· -··-· .... -·" .~.. ·-· .·~·' (2) ';;1 !: el S.P. 976093 [ e .. (§' i r-----1 ® . ,, .~· ' .. ...:,,.-: _'')-.:::;:7 • .:IP 'Q.. ' ~ ! @I,, • JI se~H Ou.n ; ---tfe""\~ nu • .~,2., -.sS.E. 135TH • ~:e: .. . 2 --.• 'C7' ST.: "'· ['NIU·-y. ~ " • '• 1 • & ""' .•.• •11011 : : 0 ' -. . '. .. i w, . " ~ I~ _i ~ s ; , ~ . . t.,. / t 0i: • ~ " • 4 = 5 i ' • Cedar River :; ,._ (31 "" · 7 l ,-z - r.: : '@ 9.a•.aao,.,. • ~ ;; • .,, , " · ..., Watershed ;; t i@> @ \\V 1,)3 (u'\ fs\.o • -1311 14~ llS I I t .1 ~ 31 3 -/ I._V \...:.!..) ~-1!3 • '°'E I~= = : I!! --, "J.o'° I '-0/1' ® rii' , ... ..._~. , ~ ··· ,,. •~~.-.. hno~ ··-.) n11 ,.,.,, • • • n'1 lw.,, 5'2.! cEl,Ps . <RENTON AVE.,, "' •S.E. 136TH ST. !-<- "'"·~' ·~U3 I . \ .... • G". 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"' ,,,u .... ·-,,~, .. _ ~· ·1 o. ,· I " . , ~!~ o~ ... ; .Ii C ," , 2 R 1 · q LL, , ", 1 , Cl, (; , i ~! • .J~:\1 .. 1 JF.~:,;, 5<•>c•~a_o~ s; l'N,s1 •, : I• ® : @ @ ~ "'"' -@ @ ® ' , ' \l I ~ ., } . -~I -=~ 2 I sf' r 080 9 • 1~ ~ GJ. · ! !iii i ',5.-11' "",,,.,. CJ ~ v P • ~~~. e I I" I @< ;fl ~c. . @ . ..~ T,'S"' _,,;; . . ___ _ ,... ~ .. _ .... .;, ~------- --1 t= c "''· r., . : .Sn,.~, ' ;,,: . _·, •• 4 -• ~ ... ---I. T . -·-·-ST-·-'; _____ ,_,_ --~.!..:._,---,,·-'--·-·-·-·-·-·-·-·-·-·-·-·~·S.E-:-·-·y-·-144 H--· ~ ·rJ ''--------- ii i! -; 23 1j, t (N:L.SHULT~~. NOT O,EOEO. ..•. . _. >, • - LEGEND ;;ii''. ,.) · Culvert t-t Ditch Catch Basin IE, Sheet Flow Location ID ·~ ® lt~OZO~J lr.i'lQ!IU'.flmJ((!, IP' .1 ® SCALE: 1" = 300' TITl.E Figure 5. Dowm,tream Conveyance System PAGE OA1" 3-4 6/11/01 's::;, 137 . Table 1. Description of Downstream Conveyance System Site Visit on 0110510! Basin: Easterly basin draining to 160"' Ave SE (including upstream areas) Weather: Rainr Ili'<i:tatiinc /i .• • Diainage. < . • . • iJ)rJ1iriage . . Slope Distancefrom/ • Observatfoiis'o(Fielil' 111\ri ;, :}:;:]in;g~~rf~~· tl~~!t~i,~f, • • ... · . .. SitiI>iicharge' ; Irs;iEf £tilThi1 ll~~1%!t ~~~ffii ~:~l~t~~?: ·114 ~~~;;~D,~ t,,s~~~"iI~~!i~~1t·g,·~:~~a;~fir~i 56 58 I . 2 3 4 5 Sheet flow / Pasture ar_ea drains I 2 j "Yest boundary of towards site site Sheet flow 12-inch diameter CP Length =90' Roadside ditch Width: 1.5' Depth: 2' Side slope: 2: I North boundary ditch Width: 1.5' Depth: 1.5' Side sl<>I'_e: I: I North boundary ditch Width: 1.5' Depth: 3,0' Side slope: 2: I North boundary ditch Width: 2,0' Depth: 3.0' Side slo]>_e: 2: I Forested area I I I South portion of HW=l' Earth-lined ditch; east sideofl581h Avenue SE Earth-lined ditch Grass-lined ditch w/ briars Earth-lined ditch 2 4 3 2 2 site Northwest corner of site North of site North boundary of site / North boundary of site North boundary of site Minor erosion Somewhat undulating topography; runoff from south boundary of site flows south Conveys drainage from west ditch of 158th Avenue SE Collects fll)lOff from roadside ditches along 158th Avenue SE and areas to north of site Collects runoff from areas to north of site Collects runoff from areas to north of site Table 1 (continued) Basin: Easterly basin draining to 160"' Ave SE i;jo~~iit:o . . . Drainage . · .. ·•· .J>rainage · [)F}?Jif -'.•'Coniporieiit Type, . . ; Compiirient rf;i~Jt Name, iifd,:c~!Ze :::·•··. ,j:;!Jf!~~r~:011 · 'ig:;Ji; }:'ype: sheet. tl~.w; ~)Vale, ••. ' . t•.i!f*1ag~ ~!!Sin, ... ·.. . ·;,, .. stream, channel;'p1pe. yegebitton;ct9yer;depth, f/· :; size: diairieteiLwidiJ!; ,.'/iypkofsi:nsiiive area . 6 I North boundary ditch I Dense briars 7 8 9 10 11 12 Width: 2.0' Depth: 3.0' Side slope: 2: 1 Roadside ditch Width: 1.5' Depth: 2' Side slope: 1.5:1 Side channel from onsite wetland Width: 2' Depth: 1.5' Side slC>])e: 2: 1 Roadside ditch Width: 1.5' Depth: 2' Side slope: 3:1 12-inch diameter CP Roadside ditch Width: 2' Depth: 1.5' Side slope: 3: 1 Grass-lined ditch; west side ofl58"' Avenue SE Wetland Grass-lined ditch HW=l' Grass-lined ditch 12-inch diameter CMP I HW=l.5' Slope Distance from SitfDischiifge ·,.I. .. . .;.,.,,:,\\:t 1 · I I (%) 3 4 I 0.5 3 2 3 2 1• J/4ri~'.320 0 ~, . -_-.,, ...... _.,··,·,. Northeast corner of site East boundary of site I East boundary of site East boundary of site 40 60-400 400 Existing Problems Potential Problems constrictions, under capacity, ponding, overtopping, scOuring, bank sloughing, ' sedimentation, incision, other .erosion No scouring or erosion; road embankment is stee but stable None None Observations of Field.·· Inspector:· Resliui'ci" Rt:~t:::~1:fci{ii' tributary area,· likelih~od of; . problcm,'overtlow'.,t.~:;:.,., pathways, potb1tial urtpacts' Collects runoff from areas to north; ditch jogs around utility box; ditch from west side of 160th Avenue SE ioins in Small amount of flow observed '-___/ Table 1 ( continued) Basin: Easterly basin draining to 160" Ave SE I~~ f ~~I~if ~l\l:t~;··&,..,. ·~::~i~t i~1·~r.t:J,p ;;;i::r&:~11 f ~;r'd j9~;!!'ril 1~!1~1:1~1} ttl8'1i~{ . ,::ri1f.tl!!lfrit Jt,tt!!ii·;iJ!l:!i!:1~!i1 m:;;~iSi' 13 Roadside ditch Grass-lined ditch 3 420-660 Width: 2' Depth: 1.5' Side slope: 2: I 14 \ 12-inch diameter CP I HW=l.5' I 3 Length=40' 15 I 24-inch diameter CMP I HW=l' I 2 16 17 18 19 Length= 20' Roadside ditch I Grass-lined ditch Width: 2' Depth: 1.5' Side slope: 2: I 18-inch diameter CMP I HW=l' Length = 80'. Roadside ditch Width: 3' Depth: 3' Side slope: 2: I Braided channel Earth-lined ditch Forested 3 3 2 I 660 780 820-860 860 950-1,000 l,000-1,100 Downstream end of culvert is crimped Some sediment at culverts Past drainage problem reported at this location; See Drainage Complaint No. 97-0423 Minor erosion at outlet of 18-inch diameter CMP Culvert crosses from west to east side ofroad Water flows east among trees ,- ~ Table 1 ( continued) Basin: Easterly basin draining to 1601h Ave SE '"'"~1~-!tB&11~~~;~~,,~~~2;:~·~:;t:~~I 21 22 23 24 25 26 .,., .·~~-· c.~·c.·nc,c.· ~,~'"''' ,.,cc,~~&i11~~!~~%:~i~:~~~~iUir 1!~1:i~bt!!=~S!iI!1 ;~~E;&wi Channel Width: 2.5' Depth: I' Side slope: 2: I 12-inch diameter CMP 12-inch diameter culvert Channel Width:2.5' Depth: 2.5' Side slope: Vertical 24-inch diameter culvert Channel Width: 3' Depth: 4' Side slope: I: I Forested, potential 0.5 l,100-1,200 I Flow path through wetland area middle of ponded area Earth-lined I 2 I l,200-1,350 Earth-lined bottom; concrete block walls Earth-lined 1-2 1-2 2 3 I 1,350 I 1,450 I 1,4 70-1,600 1,600 1,660-1,700 I Water likely backs up under hi flows I Potential overtopping of drivewa Past drainage problem reported at this location; See Drainage Complaint No. 97-0206 Highly eroded banks I Erosion likely to continue I Culvert passes under horse corral Culvert passes under driveway Culvert has trash rack and concrete headwall inlet __ ,.-,'; Table 1 ( continued) Basin: Easterly basin draining to 160 1• Ave SE 1t~!\rf 1i~,i ri[iijiL,ri'."!l[ilJii · :~:r~~jji~-J 11lilf1tl t~11Jiix1;: 'ti~i]~i) ;H~tii,!i~iu} 1 '.:JL~ii;it~6=i;;1J;:0~1~lrlii1 27 Channel Earth-lined 1,700-2,000 Eroded banks Erosion likely to Channel heads down hill Width: 3' continue towards SE 144th Street Depth: 4' Side slope: I: l Table 1 ( continued) Basin: Westerly basin draining to 156th Ave SE l:'.i~-;f ,i@;l~!l1W:~}~~rf~~~!!!!~=;i~:~,~~i't~:~:m1 1il~~i1i: .t;~rLt:tAt l~-~~.; ''.:~!::~ t '.::1{~.;u~,~i;;i~ :i;.:a~~~!i:!i.riY..r:;·: -~~~~if~ I 57 Sheet flow Forested area 2 Southwest comer I Runoff from southwest of site comer of site sheet flows towards SE 13 8th Place 30 I Roadside ditch. Width: 1.5' Depth: 1.5' Side slope: 3: l 31 I Ditch Width: 0.5' Depth: 0.5' Side slope: 3: l 32 I Sheet and/or shallow channel 33 I Roadside ditch Width: 2' Depth: 3.5' Side slope: 2: I 34 I 12-inch diameter CP 35 12-inch diameter CP 36 12-inch diameter CP Grass-lined ditch Shallow grass-lined ditch Grass area; no distinct flow path Earth-lined ditch HW=l' HW=l.5' HW=l.5' 2 2 3 5 4 4 4 Road improvement along SE 136th Street Road improvement along SE 136th Street Road improvement along SE 136th Street 0-150 150 220 310 None Upstream end of culvert partially blocked with leaves Flows to east towards Location I Flows to grass area to west in road ROW Access to vacant lot Table 1 ( continued) Basin: Westerly basin draining to 156th Ave SE J?~ '.J;~~~.'1ffle~,·~~~1~ftt~~,~,i~~i;F;;!;~~~;g iflllitt~i!~~}'};am~~ , .. · i: jW~;!~Jil1i;tJx,~!!ili~!JE$1~;il~\~~i~1flt1 37 Roadside ditch Earth-lined ditch 5 340-470 4-6 inches of Debris has Width: 2' leaves in bottom potential to block Depth: 2.5' of ditch downstream Side slope: 2: I culverts 38 \ 12-inch diameter CP I HW=l' I 4 I 470 I Upstream end of 39 40 41 42 43 44 12-inch diameter CP I HW=i.5' crossing SE 137th Place Type I CB 12-inch diameter CMP in 12-inch diameter Nl2 out Type I CB -grate inlet 12-inch diameter Nl2 Type I CB 12-inch diameter N12 Type I CB 12-inch diameter Nl2 Type I CB 12-inch diameter N12 4 4 4 4 3 3 550 600 660 870 950 1,100 culvert partially blocked with leaves Table 1 (continued) Basin: Westerly basin draining to 156th Ave SE ~J.{o.~atj9n .·•·· .. · ... .Dtiiinage ......... ·.. <Dfai11ilge . ~lope· .. ·· Distance from Potential Obsen'litfon(~ftieft( ':f Jfi~'Iri ;.c;t~;~;i:}[fe, d;%~J!f~JI{{\ .. \ . Sit,e pisc~~rg~, . . . Probl~y:s :1~s~if~r1t11~ ~t~tt~ =!¥1~~~::, ;;;2:;!f~~~ · :;,1 1~i§~;~~\~~:~;:1t:ii~~ii!:8:i~t;r:~'?i~f~li1 45 12-inch diameter CP 2 1,240 Collects runoff from SE from east 139th Place 46 I Type I CB -grate inlet I I 3 I 1,240 47 48 49 50 51 52 53 54 12-inch diameter Nl2 in 12-inch diameter CP out Type I CB -grate inlet 12-inch diameter CP from east Type I CB -grate inlet 1,2-inch diameter Nl2 out 12-inch diameter Nl2 outlet 12-inch diameter CP 12-inch diameter CP Roadside ditch Width: 1.5' Depth: 2' Side slope: 2:l / ', r Roadside ditch HW= l' HW= I' Grass-lined ditch Grass-lined ditch; ditch flattens out 3 I 1,290 2 1,290 3 I 1,320 3 I 1,460 3 1,470 . 3 1,520 3 1,550-1,750 2 1,750-2,000 I I I Half-filled with sediment I Collects nmoff from SE 139th Place Water likely spreads out onto adjacent pasture Table 1 ( continued) Basin: Westerly basin draining to 156 1 • Ave SE , ])rJ!inage . > .. .'.:Draitfa.ge .· · Shipe Distance}i:o!n; ... Conip1111e~tTy~,, · _ '~opip~·nent--· . )Site])isc~iitg~{ .·· ,,,Na\!!~~~~eJ>; .~;-~;~~~ie::~~-·'•·• ~~~ > · •.. ,. ;,:f~~J,f,1--./ ·1 •• B;;rf'·· ,i;1~jfi~1 ( ).·u 4 '1iltli1~-z' ._.1tili~iJI~~E~1-- 12-inch diameter CP \ HW = l' \ 2 I 2,000 I Past drainage problem reported at this location; See Drainage Complaint No. 97-0318 ~ Observ.i.dioniof•!ieJd;., . In~~~t~~~tf ~1t~l t~l&tlfi ,. ) !4. :Flow Control and Water Quality Facility'Analysis and Design Part A: Existing Hydrology The site consists of two basins. The topography of the east basin generally slopes from the northwest to the southeast (Figure 3). The topography of the west basin generally slopes from the east to the west. Cover types on the site include a single-family residence (Photo I in Appendix A. I), forest (Photo 2 in Appendix A. I), and pasture. A Class 2 wetland has been identified in the northeast portion of the site. Cover types and areas used in the stormwater design for existing onsite conditions are summarized in Table 2. Part B: Developed Site Hydrology The proposal for development includes building 75 single-family dwellings on about 12 acres. The proposed site plan is provided in Figure 6. Cover type areas for developed onsite conditions are summarized in Table 2. Under developed conditions, the developed portion of the site, including offsite road improvements, will consist of 4.53 acres of grass and 7.23 acres of impervious area. Under developed conditions, stormwater from the site and road improvements will be collected and treated onsite to basic water quality standards. Stormwater will be managed separately in the east and west basins. In the east basin, stormwater from the site and a portion of improvements along SE 136th Street will be collected and managed in an onsite combined wetpond/detention pond. The outfall of the pond will discharge to the drainage ditch along the west side of 160th Avenue SE. Stormwater from a 0.33-acre portion of SE 1361h Street will bypass the onsite stormwater facility, but will be treated to basic water quality standards with a small wetvault located near the intersection of SE 136th Street and 160th Avenue SE. The stormwater pond in the southeast corner of the site will be designed using a downstream point-of-compliance to account for the bypass from SE 136th Street. In the west basin, stormwater from the site and a portion of improvements along SE 1361h Street will be collected and managed in an onsite detention vault and subsequently treated by a biofiltration swale. Stormwater from a 0.19-acre portion of SE 136th Street will bypass the onsite storm water facility. The storm water vault in the southwest corner of the site will be designed using a downstream point-of-compliance to account for the bypass from SE 136th Street. Runoff from the existing impervious area of 0.16 acre on SE 136th Street will be treated onsite in lieu of the bypass. 4-1 Evenddl Plat Pre/imfr,ary 11R-June 2001 Table 2. Existing and Developed Site Basin Conditions Existing Conditions Suhhasins KCRTS Till-forest Till-pasture Wetland Till-grass lmperv Basin (AC) (AC) (AC) (AC). (AC) East Basin exeast Site 7.54 · 1.74 --- SE 136th Street Improvements -0.47 --0.09 Subtotal 7.54 2.21 --0.09 West Basin exwest Site 0.44 1.12 --- SE 136th Street Improvements -0.29 0.07 Subtotal 0.44 1.41 --0.07 Grand Total 7.98 3.62 --0.16 Developed Conditions Subhasins KCRTS Till-forest Till-pasture Wetland Till-grass Imperv · Basin (AC) (AC) (AC) (AC) (AC) East Basin deveast Lots 3.79 4.82 RID 0.16 0.66 SE 13 6th Street Improvements -0.56 Subtotal ---3.95 6.04 West Basin devwest Lots 0.58 0.73 RID 0.10 SE 136th Street hnprovements -0.36 Subtotal ---0.58 1.19 Grand Total ---4.53 7.23 Note: 0.19 acre of impervious of SE 136 Street improvements bypass the RID facility in the west basin. 0.33 acre of impervious of SE 136 Street improvements bypass the RID facility in the east basin. 4-2 Total (AC) 9.28 0.56 9.84 1.56 0.36 1.92 11.76 Total (AC) 8.61 0.82 0.56 9.99 1.31 0.10 0.36 1.77 11.76 Part C: Performance Standards A summary of flow control, conveyance, and water quality treatment performance standards for the project is presented in Table 3, below. Table 3. Summary of Performance Standards Cateiwrv Performance Standard Source Flow Control • Level 2 RID a 1998 King County Surface Water Design Manual; Applications Map Conveyance System a Provide conveyance for a Surface Water Design Capacity developed 25-year storm Manual Section 1.2.4.1 Water Quality a Basic water quality treatment a Surface Water Design Treatment Menu using a wetpond in the east Manual Section 1.2.8.1; basin and a biofiltration swale Applications Map or wetvault in the west basin Source Control a None proposed Oil Control • The site does not meet the • Surface Water Design definition of a high-use site Manual Section 1.3.5 4-3 Evende/1 Plat Preliminary 11R -June 200 I Part D: Flow Control System KCRTS was used to design the proposed stormwater facilities. Procedures and design criteria specified in the 1998 King County Surface Water Design Manual were followed for hydrologic modeling. Descriptions of the storm water systems and details of the design analysis are provided below. A plan view of the storm water systems is provided in Figure 6. For stormwater facility designs, the reduced KCRTS time series data set was used for the Sea- Tac rainfall region with a correction factor of 1.0. Documentation of the KCRTS input and output including descriptions of executable files, reservoirs, and times series is provided in Appendices C and D. Under developed conditions, stormwater from the site and offsite road improvements will be collected and treated onsite to basic water quality standards. A combined wetpond/detention pond will be used to manage runoff in the easterly basin. A small wetvault will provide water quality treatment to a portion of SE 136th Street that bypasses the stormwater facility. A biofiltration swale will be used to manage runoff in the westerly basin. Level 2 RID standards are required by the King County Flow Application Maps and recommended by Lower Cedar River Basin and Nonpoint Action Plan. The natural discharge locations from the site will be maintained at the outlet of the proposed stormwater facilities. Stormwater from the development in the easterly basin will be managed with a combined wetpond/detention facility. Stormwater from the development in the westerly basin will be managed with a detention vault facility followed by a biofiltration swale. Level 2 RID standards are proposed for both facilities. The stormwater facilities shown in Figure 6 meets Level 2 RID criteria and basic water quality requirements. Flow duration curves at the downstream point-of- compliance are provided in Figures 7 A and 7B. Peak flow rates for the downstream point-of-. compliance, under existing and developed site conditions follow Figures 7 A and 7B. The downstream point-of-compliance includes runoff from portions of SE 1361 h Street that bypasses the stormwater facilities. The duration curves and peak flow rates; shown for existing and developed conditions, indicate that Level 2 RID criteria are met. The stormwater facility in the east basin requires approximately 117,770 cubic feet oflive storage, excluding a factor of safety, to meet Level 2 RID standards. The stormwater facility in the east basin requires approximately 17,921 cubic feet of live storage, excluding a factor of safety, to meet Level 2 RID standards. A factor of safety of 5 to 10 percent will be added to the final design volume. Part E: Water Quality System Basic water quality standards apply to the site. A basic wetpond will provide treatment for the site's easterly basin. A small wetvault will provide treatment for a portion of road improvements along SE 1361h Street that bypasses the easterly stormwater facility. A biofiltration swale will provide treatment for the site's westerly basin. Alternatively, a wetvault may be used to treat stormwater collected from the site's west basin. A treatment trade is proposed for stormwater collected from the road improvement area along SE 136th Street in the site's westerly basin to account for a small area of the road improvement that bypasses the westerly stormwater facility. 4-4 Evendell Plat Preliminary DR-June 2001 Runoff from an area of existing pollution generating impervious surfaces equivalent to the area bypassed will be collected from SE 136th Street and treated onsite. · The required wetpool volumes for the treatment facilities were determined using equations provided in Chapter 6 of the 1998 Surface Water Design Manual. Basin areas, annual runoff volumes, VbNr ratios, and required volume for the wetpond are given in Table 4. 4-5 EPenddl Plat Preliminary TIR-June 2001 D D • '. 1. '· \\ • ~?.'::~._-~::.~·-. (:.· • I • I • I • I I "' ..;----- -/l 'deveast/ <t \ \ = ~ ___,, -~----· .. - 3~'5G---8 ~ 9~ ·-·-~~~.--;Jt~d(Yllei 4 V 11 7 Ferj!_ ,...:J,1 ·s;--~_.; ~-. . i --·----r--=-v G · 11 . iiUDIDDllflifii:QDJ1a1ijl,lliif Offsite AC ~ Area= o.94 '~ IL__l -·~~ _J L llf- J -·I _J_ _J _J 5'Wood~ I Lot 7 Rhse ' ~ ~ ~ I I . I . SE 1Jffilf WAJIB QlWuY Yftl:H I \ / ur« X JO'L -X 11.S'll ONSIDE DIii.) TOP OF VNJLT• ,48U ' • I . WATER SURFACE--482,.0 I ear. DEr.• 4n .D 1• -IC&SdH")rG' I DEi'. YOL-1:aD a:' . -~-=-~'!11!/.J~~-d~ 3f!!:Jf7 St;fi4~-~-~ ~: ; .. - ~· y/ r---.! , -:--- .', I --W£1lAND & I j 4:-. 8UfITR--_ ,!l , ((0 _ -0,z~\ AC . '~--47_) 51 i ~~n~ . ~ . _ (\)i _ \\ FQ) t -i-. J__ ~-H ./ ·J ~-"', l::s fl· I . . · ./ . ;f/ "-\ •-f-f-'·-'-__ 43 I ~. 37 '· / )! "- " L~ I --· -~ --· '-;,-"-'"- -~ 1-7·1 I~! 41 ! /1 36 j 35 _/ '. o"'--. ~ Jz"-¥e'.'!1.',~~d-.J. ;:::, ,. X, 1r~ -""( -r, 1· -------....s,11 ~ r -r--,-7 . ' _,,. .. 11"-=. ... • 56 I 75 i 74 i 73 "·~ '( /· : '· .. ,/ ~ I; Iii --/ I y y· -JI I-·-· ·-' "l',.1' ·.r'·-/: . ·-· I I ·i: ·...._ 57 y-~/-72 j ~ 32 ..< . : _J ( __ 1-~ i ru·---/-.:..J 30 ~/ _i~ ,$~i j_ -;;·j ~~1-· .J/ .l.~ ---.£---TE 1 -·-?"·i ,• / ! . /---·-·1 · . -~e-r....-L·-·i ii7·JBACi~.=- e1 Yeo! 89 y 68 i jii: ~mr.sii-~ . .l he! ear.-<a,i-~ :z ·--~---i I / 1-·-·-·Lt 1...,-~ur-____..._;.-,, _ _.;-· 82~-i 1· ? •, '1~ PROY •. ~ocr: :~:~ ~ -.;r-t -· '"< REQ'D WET • 31,400 / . • • PR<N'. VOL• ~ --~--. 1B4 I 65 / --·-·1/ ,oo . s. -51' I I /I 88.A --- u -,~__J l r-~ • I -~ =-~-~~)(~~=;·,--..aj.=1.-3= • / '~r rr-i 7 ,li\~ ? \ ~~n~:r y ~~{J.[iif~Sfi-eef-1W "I. \\\IV r Ar. I I /111 +~ 19 j :iq j 21 /'. 22 I 23 biJ I ! 26 , . I 1, ,.. I ,1 ... ! 1 I::; 4~ ~ ~ :::E l,J I-I- -<( Ill z _J ~:s a. _J a::: Q. .JI Wz LL' I-(!) 0 <-z := Ill w :::E l,J > a::: C L,.J 0 I- Ill u:i "' . ,.. fl. :;t • C I bG i [ A . -.<.,g . J,,t ~ j .•• GI ~:..J IW iW II) 5' I~ '~ .a =, lo [O Z:::1 1--·-,-·-Q ' . t,Gi:;l;f ! A_,=> I _l,a:l~8 i i ! 1,8 i'-' o ;,j § 1? as_vi10:. t:t= i~ lo !! ~ l"l{:i! ~ t,.a :ii I . 1. ui u. ~ I ' Cl> -"' 0:: ;: 0 ii: 0.7 -+--Existing --s -Developed 0.6 0.5 0.4 0.3 0.2 0.1 O+------+-----t-------l-------1----"'-----l 1.00E-05 1.00E-04 1.00E-03 · 1.00E-02 1.00E-01 1.00E+OO Probability of Exceedence Figure 7 A-Flow Duration Curves for RID -East Basin. Duration curves are shown at the downstream point of compliance in the easterly basin. The pond is designed to meet Level 2 RID standards. 4-7 Predeveloped Peak Flow Rates -East Basin Flow Frequency Analysis Time Series File:exeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 0.645 2 2/09/01 18:00 0.891 1 100.00 0.990 0. 200 7 1/05/02 16:00 0. 645 2 25.00 0. 960 0.517 3 2/28/03 3:00 0.517 3 10.00 0.900 0.037 8 3/24/04 19:00 0.508 4 5.00 0.800 0.303 6 1/05/05 8:00 0.457 5 3.00 0. 667 0.508 4 1/18/06 20:00 0.303 6 2.00 0.500 0. 457 5 11/24/06 4:00 0.200 7 1.30 0.231 0. 891 1 1/09/08 9:00 0.037 8 1.10 0.091 Computed Peaks 0.809 50.00 0.980 1 .. Developed Peak Flow Rates -East Basin Flow Frequency Analysis Time Series File:poceast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 0. 611 2 2/09/01 19:00 1.13 1 100.00 0.990 0.177 7 1/05/02 16:00 0. 611 2 25.00 0.960 0.517 3 3/06/03 20:00 0.517 3 10.00 0.900 0.182 6 8/26/04 2:00 0. 472 4 5.00 0.800 0.173 8 1/05/05 8:00 0.214 5 3.00 0.667 0.214 5 1/19/06 2:00 0.182 6 2.00 0.500 0. 472 4 11/24/06 6:00 0 .177 7 1. 30 0.231 1.13 1 1/09/08 11: 00 0.173 8 1.10 0. 091 Computed Peaks 0.955 50.00 0.980 4-8 Evende/J Plat l'n,/iminary 11R-June 2001 b • 0.2 _..__Existing --El -Developed 0.18 0.16 0.14 13_ if 0.12 !2.- Cl) -.. 0:: ;: 0 ii: 0.1 0.08 0.06 0.04 0.02 0 1.00E-05 1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+OO Probability of Exceedence Figure 7B. Flow Duration Curves for RID -West Basin. Duration curves are shown at the downstream point of compliance in the westerly basin. The pond is designed to meet Level 2 RID standards. 4-9 ) Predeveloped Peak Flow Rates -West Basin Flow Frequency Analysis Time Series File:exwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 0.138 2 2/09/01 18:00 0.235 1 100.00 0.990 0.059 7 1/05/02 16: 00 0.138 2 25.00 0. 960 0 .129 3 2/28/03 3:00 0.129 3 10.00 o. 900 0.024 8 8/26/04 2:00 0.122 4 5.00 0.800 0.074 6 1/05/05 8:00 0.116 5 3.00 0.667 0.122 4 1/18/06 16:00 0.074 6 2.00 0.500 0.116 5 11/24/06 4:00 0.059 7 1. 30 0~231 0.235 1 1/09/08 6:00 0.024 8 1.10 0.091 Computed Peaks 0.202 50.00 0.980 Developed Peak Flow Rates -West Basin Flow Frequency Analysis Time Series File:pocwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 0.140 2 2/09/01 18:00 0.197 1 100.00 0.990 0. 059 8 1/05/02 16:00 0.140 2 25.00 0. 960 0.110 4 3/06/03 19:00 0.135 3 10.00 0.900 0.067 7 8/26/04 2:00 0.110 4 5.00 0.800 0.068 6 10/28/04 16:00 0.107 5 3.00 0.667 0.107 5 1/18/06 20:00 0. 068 6 2.00 0.500 0.135 3 11/24/06 4:00 o. 067 7 1. 30 0.231 0.197 1 1/09/08 9:00 0.059 8 1.10 0. 091 Computed Peaks 0.178 50.00 0.980 4-10 Evenddl PlatPreUminary 11R-June 2001 .. ' ' ' Table 4. Wetponil Sizing Calculations East Basin Residential Lots/Onsite Road 0.00 3.79 4.82 8.61 9,018 3.0 RID Tract 0.00 0.16 0.66 0.82 1,082 3.0 SE 136th Street Improvements 0.00 0.00 0.23 0.23 353 3.0 !Total 0.001 3.95! 5.711 9.6611 10,4521 E t B . SE 136th St t I as as1n -ree t mprovemen s 5071 3.0 I SE 136th Street Improvements 0.00 0.00 0.33 0.33 '-lT_ot_a1 ___ __,_ __ o_.oo_.! __ o_.o_o.._! ___ 0._33_..! __ o_.3__,3 j ~j __ 5_07~! West Basin* Residential Lots/Onsite Road 0.00 0.58 0.73 1.31 1,368 3.0 RID Tract 0.00 0.00 0.10 0.10 154 3.0 SE 136th Street Improvements 0.00 0.00 0.17 0.17 261 3.0 !Total o.ooj 0.581 1.001 1.581 j 1,783 j ~-~-~ Mean annual storm= 0.47 * Either a wetvault or biofiltration swale will be used to treat water in the west basin. 4-11 27,053 3,245 1,059 31,3571 1,520 I 1,520 i 4,105 461 783 5,3491 I , . •• Stormwater RID System Conveyance The onsite stormwater system will be designed to convey the 25-year peak flow rate for conveyance systems upstream of the stormwater facility. A conceptual design of the conveyance system is shown in Figure 6 of Section 4. 5-1 Evenddl Plat Preliminary T1R-June 20/JJ t i. :..1 6; '.SpecialReports and Studies · . A summary of special reports and studies conducted for the Evendell Plat is presented below. Table 5. Summary of Special Reports and Studies Study/Report GeotechnicaVsoils Wetlands Evendell Plat, King County, Washington. Wetland Delineation and Report Floodplains Groundwater Anadromous fisheries impacts Hydrology Level I Downstream Drainage Analysis (Section 3 Evendell Plat Preliminary Technical Information Report) Water quality Structural fill Evenddl PfaJ Preliminary 11R-June 2001 6-1 Date Conducted NIA June 2001 NIA NIA NIA January 2001 NIA NIA 9?'Bond Quantities,7Fiicilify Summaries; and Declaration of Covenant.· A bond quantities worksheet for the project will be prepared during final engineering for the submittal. A summary of onsite conveyance and water quality facilities is given in Figure I 0. None of the facilities will be privately owned or maintained. Therefore a declaration of covenant is not needed. 9-1 EvemldJ Plat P,./uninary 77R-.June 2001 ) Figure 9. Site Improvement Bond Quantity Worksheet '. ,. ~ .) 9-2 Evendd/ Plat Preliminary T1R-June 2001 Figure 10. Flow Control and Water Quality Facility Summary Development: Evendell Plat Date: 6-11-01 Location: King County Township 23N, Range 5E, Section 14 ENGINEER Name: Ed McCarthy Firm: Haozous Engineerino, P.S. Address: 14816 SE I 16th Street Renton, WA 98059 Phone: ( 425) 235-2707 Developed Site: 12 Acres Number of detention facilities on site: 1 Combined Wetpond/R/D 1 Vault Downstream Drainae.e Basins Lower Cedar River Number & type of water quality facilities on site: _l __ biofiltration swale (regular/wet/ or continuous inflow?) _I __ combined detention/WQ ponds __ flow dispersion trenches ___ combined detention/wetvault ___ compost filter __ filter strip ___ landscape management plan DEVELOPER Name: Mike Romano (representing U.S. Land Develonment, Jnc.i Firm: U.S. Land Develooment Associates. Inc. Address: Clo Centurion Development Services 22617 8th Dr. SE Bothell, WA 98021 Phone: ( 425) 486-2563 Number oflots: 75 single-family residences Number of infiltration facilities on site: 0 Immediate MaiorBasin Orting Hills Cedar River __ sand filter (basic or large?) ___ sand filter, linear (basic or large?) ___ sand filter vault (basic or large?) _] __ vault _2 __ energy dissipation structure(s) Basic pond (basic or large?) ___ oil/water separator (baffle or coalescing plate?) ___ catch basin inserts: Manufacturer __________________ _ ___ pre-settling pond ___ pre-settling structure: Manufacturer __________________ _ __ flow-splitter catch basin DESIGN INFORMATION Easterly Basin SE 136" Street Westerly Basin !Easterlv Basin) Water "ualitv Desi= Volume (CF) 31,400 5,300 Biofiltration Swale Onsite Area (AC) 9.43 0.00 1.41 Offsite Area(AC) 0.56 0.33 0.36 Type of Storage Facility Combined Wetvault Vault Wetoond/R/D Reauired Live Sto=e Volume (CF) 118,000 N/A 18,000 Figure 10 ( continued) DESIGN INFORMATION .. Easterly Basin SE l 36~ Street Westerly Basin (Easterlv Basin) Predeveloped Runoff Rates 25-year (CFS)** 0.645 0.023 0.138 Post-RID Developed Runoff Rates 25-vear /CFS)** 0.611 0.069 0.140 •• Based on KCRTS I-hour peak rates for the proposed developed area. I. The conveyance and water quality facilities for the Evendell Plat will not be privately maintained nor do they contain non-standard features. The table below specifies the maintenance requirements for each component of the storm water facility being constructed. Applicable maintenance requirements, taken from the 1998 Surface Water Design Manual, are referenced to the pages that follow. Table 7. Summary of Maintenance Requirements for Stormwater Facilities Maintenance Requirement • No. I -Detention Ponds • No. 4 -Control Structure Restrictor • No. 5 -Catch Basins • No. 6 -Debris Barriers • No. IO -Conveyance Systems • · No. 13 -Water Quality Facilities -Wetponds • No. 13 -Water Quality Facilities -Wetvaults • No. 13 -Water Quality Facilities -Biofilration Swales 10-1 Evendell P/gJ Preliminary 71R-June 2001 0. 1 -DETENTION PONDS General Trash & Debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office ~arbage can). In general, there should be no visual evidence of dumping. Poisonous Vegetation Any poisonous or nuisance vegetation which may constitute a hazard to County personnel or the public. Pollution Oil, gasoline, or other contaminants of one gallon or more Q! any amount found that could: 1) cause damage to plant, animal, or marine life; 2) constttute a fire hazard; or 3) be flushed downstream during rain stonns. Unmowed Grass/ If facility is located in private residential area, Ground Cover mowing is needed when grass exceeds 18 inches in height. In other areas, the general policy is to make the pond site match adjacent ground cover and terrain as long as there is no interference with the function of the facility. Rodent Holes Any evidence of rodent holes if facility is acting as a dam or benn, or any evidence of water piping through dam or berm via rodent holes. Insects When insects such as wasps and hornets interfere with maintenance activities. Tree Growth Tree growth does not allow maintenance access or interferes with maintenance activity (i.e., slope mowing, silt removal, vactoring, or equipment movements). If trees are not interfering with access, leave trees alone. Side Slopes of Pond Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Storage Area Sediment Pond Dikes Settlements Emergency Rock Missing Overflow/Spillway Accumulated sediment that exceeds 10% of the designed pond depth. Any part of dike which has settled 4 inches lower than the design elevation. Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip.rap on inside slopes need not be replaced. 10-2 Trash and debris cleared from site. No danger of poisonous vegetation where County personnel or the public might normally be. (Coordination with Seattle-King County Health Department) No contaminants present other than a surface film. (Coordination with Seattle/King County Health Department) When mowing is needed, grass/ground cover should be mowed to 2 inches in height Mowing of selected higher use areas rather than the entire slope may be acceptable for some situations. Rodents destroyed and dam or benn repaired. (Coordination with Seattle/King County Health Department) · Insects destroyed or removed from site. Trees do not hinder maintenance activities. Selectively cultivate trees such as alders for firewood. Slopes should be stabilized by using appropriate erosion control measure(s): e.g., rock reinforcement, planting of grass, compaction. Sediment cleaned out to designed pond shape and depth; pond re- seeded if necessary to control erosion. Dike should be built back to the design elevation. Replace rocks to design standards. ). 4 -CONTROL STRUCTURE/FLOW RESTRICTOR Structural Damage Cleanout Gate Damaged or Missing Orifice Plate Damaged or Missing Obstructions Overflow Pipe Obstructions Manhole Catch Basin Structure is not securely attached to manhole wall and outlet pipe structure should support at least 1,000 lbs. of up or down pressure. Structure is not in upright position (allow up to · 10% from plumb). Connections to outlet pipe are not watertight and show signs of rust. Any holes-other than designed holes-in the structure. Cleanout gate is not watertight or is missing. Gate cannot be moved up and down by one maintenance person. Chain leading to gate is missing or damaged. Gate is rusted over 50% of its surface area. Control device is not working properly due to missing, out of place, or bent orifice plate. Any trash, debris, sediment, or vegetation blocking the plate. Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Structure securely attached to wall and outlet pipe. Structure in correct position. · Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Structure has no holes other than designed holes. Gate is watertight and works as designed. Gate moves up and down easily and is watertight. Chain is in place and works as designed. Gate is repaired or replaced to meet design standards .. Plate is in place and works as designed. Plate is free of all obstructions and works as designed. Pipe is free of all obstructions and works as designed. See ·c1osed Detention Systems· Standards No. 3 See ·c1osed Detention Systems' Standards No. 3 See ·catch Basins· Standards No. 5 See 'Catch Basins~ Standards No. 5 10-3 Structure Damage to Frame and/or Top Slab Cracks in Basin Walls/ Bottom Sediment/ Misalignment Trash or debris of more than 1/2 cubic foot which is located immediately in front of the. catch basin opening· or is blocking capacity of the basin by more than 10% Trash or debris (in the basin) that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in volume Comer of frame extends more than 3/4 Inch past curb face into the street (If applicable). Top slab has holes larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all material is running into basin"). Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Cracks wider than 1/2 inch and longer than 3 feet, any evidence of soil particles entering catch Qasin through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1 /2 inch and longer than 1 foot at the joint of a"ny inlet/ outlet pipe or any evidence of soil particles entering catch basin through cracks. Basin has settled more than 1 inch or has rotated more than 2, inches out of alignment. 10-4 No Trash or debris located immediately in front of catch basin opening. No trash or debris in the catch basin. Inlet and outlet pipes free of trash or debris. No dead animals or vegetation present within the catch basin. No condition present which would attract or support the breeding of Insects or rodents. Frame is even with curb. Top slab is free of holes and cracks. Frame is sitting flush on top slab. Basin replaced or repaired to design standards. No cracks more than 1/4 inch wide at the joint of inleVoutlet pipe. Basin replaced or repaired to design standards. Catch Basin Cover Ladder Metal Grates (If Applicable) Vegetation Pollution Cover Not in Place Locking Mechanism Not Working Cover Difficult to Remove ladder Rungs Unsafe Trash and Debris Damaged or Missing. Presence of chemicals such as natural gas, oil and gasoline. Vegetation growing across and blocking more than 10% of the basin opening. Vegetation growing in inleUoutlet pipe joints that is more than six inches tall and less than six inches apart. Nonflammable chemicals of more than 1/2 cubic foot per three feet of basin length. Cover is missing or only partially in place. Any open catch basin requires maintenance. Mechanism cannot be opened by on maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. One maintenance person cannot remove lid after applying 80 lbs. of lift; intent is keep cover from sealing off access to maintenance. Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Grate with opening wider than 7 /8 inch. Trash and debris that is blocking more than 20% of grate surface. Grate missing or broken member(s) of the grate. NO. 6 DEBRIS BARRIERS (E.G., TRASH RACKS) 11r!·i~i~:~~;?~~~,ttit tiit;; .. Metal Trash and Debris Damaged/ Missing Bars. Trash or debris that is plugging more than 20% of the openings in the barrier. Bars are bent out of shape more than 3 inches. Bars are missing or entire barrier missing. Bars are loose and rust is causing 50% deterioration to any part of barrier. 10-5 No flammable chemicals present. No vegetation blocking opening to basin. · No vegetation or root growth present. No pollution present other than surface film. Catch basin cover is closed Mechanism opens with proper tools. · Cover can be removed by one maintenance person. Ladder meets design standards · and allows maintenance person safe access. Grate opening meets design standards. Grate free of trash and debris. Grate is in place and meets design standards. Bars in place with no bends more than 3/4 inch. Bars in place according to design. Repair or replace barrier to design standards. 0. 10-CONVEYANCE SYSTEMS (PIPES & DITCHES) Vegetation Damaged Accumulated sediment that exceeds 20% of the diameter of the pipe. Vegetation that reduces free movement of water through pipes. Protective coating is damaged; rust is causing more than 50% deterioration to any part of pipe. Pipe cleaned of all sediment and debris. All vegetation removed so water flows freely through pipes. Pipe repaired or replaced. Any dent that decreases the cross section area of Pipe rep3ired or replaced. Open Ditches Catch Basins Debris Barriers (e.g., Trash Rack) Trash & Debris Sediment Vegetation Erosion Damage to Slopes Rock Lining Out of Place or Missing (If Applicable). pipe by more than 20%. Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Accumulated sediment that exceeds 20 % of the design depth. Vegetation that reduces free movement of water through ditches. See "PondsQ Standard No. 1 Maintenance person can see native soil beneath the rock lining. See "Catch Basins: Standard No. 5 See "Debris Barriers" Standard No.6 10-6 Trash and debris cleared from ditches. Ditch cleaned/ flushed of all sediment and debris so that it matches design. Water flows freely through ditches. See "Ponds" Standard No. 1 Replace rocks to design standards. See ~catch Basins· Standard No.5 See "Debris Barriers" Standard No.6 '0. 13-WATER QUALITY FACILITIES Trash and Debris Inlet/ Outlet Pipe Sediment Accumulation in Pond Bottom Oil Sheen on Water Erosion Settlement of Pond Dike/ Berm Rock Window Overflow Spillway Vegetation such as grass and weeds need to be mowed when It starts to impede aesthetics of pond. Mowing is generally required when height exceeds 18~inches. Mowed vegetation should be removed from areas where it could enter the pond, either when the pond level rises, or by rainfall runoff. Accumulation that exceeds 1 CF per 100Q..SF of pond area. Inlet/ Outlet pipe clogged with sediment and/ or debris material. Sediment accumulations in pond bottom that exceeds the depth of sediment zone plus 6~inches, usually the first cell. · Prevalent and visible oil sheen. Erosion of the pond's side slopes and/ or scouring of the pond bottom, that exceeds 6-inches, or where continued erosion is prevalent. Any part of these components that has settled 4- inches or lower than the design elevation, or inspector determines dike/ berm is unsound. Rock window is dogged with sediment. Rock is missing and soil is exposed at top of spillway or outside slope. 10-7 Vegetation should be mowed to 4 to 5 inches in height. Trees and bushes should be removed where they are interfering with pond maintenance activities. Trash and debris removed from pond. No clogging or blockage in the inlet and outlet piping. Removal of sediment from pond bottom. Removal of sediment from pond bottom. Slopes should be stabilized by using proper erosion control measures, and repair methods. Dike/ berm is repaired to specifications. Window is free of sediment and debris. Replace rocks to specifications. '· .~O. 13-WATER QUALITY FACILITIES Wetvaults Sediment Accumulation in Vault Damaged Pipes Access Cover Damaged/ Not Working Vault Structure Damaged Baffles Access Ladder Damage Trash and debris accumulated in vault, pipe or inleU outlet, (includes floatables and non- floatables). Sediment accumulation in vault bottom that exceeds the depth of the sediment zone plus 6-, inches. JnleV outlet piping damaged or broken and in need of repair. Cover cannot be opened or removed, especially by one person. Vault: Cracks wider than 1/2-inch and any evidence of soil particles entering the structure through the cracks, or maintenance/ inspection personnel determines that the vault is not structurally -sound. Baffles corroding, cracking, warping and/ or showing signs of failure as determined by maintenance/ inspection staff. Ladder is corroded or deteriorated, not functioning property, missing rungs, has cracks and/ or misaligned. 10-8 Trash and debris removed from vault. Removal of sediment from vault. Pipe repaired and/ or replaced. Pipe repaired or replaced to proper working specifications. No cracks wider than 1/4-inch at the joint of the inleU outlet pipe. Vault is determined to be structurally sound. Repair or replace baffles to specifications. Ladder replaced or repaired to specifications, and is safe to use as determined by inspection personnel. • _ J• 13-WATER QUALITY FACILITIES Biofiltration Swales Biofiltration swale Sediment Accumulation Sediment depth exceeds 2-inches on Grass Layer Vegetation Inlet Outlet Pipe Trash and Debris Accumulation Erosion/ Scouring When the· grass becomes excessively tall (greater than 10-inches); when nuisance weeds and other vegetation starts to take over. Inlet/ outlet pipe clogged with sediment and/ or debris. Trash and debris accumulated in the bio-swale. Where the bio-swale has eroded or scoured the bottom due to flow channelization, or higher flows. 10-9 No sediment deposits on grass layer of the bio-swale, which would impede.filtration of runoff. Vegetation ls mowed or nuisance vegetation is eradicated, such that flow not impeded. Grass should be mowed to a height between 4 inches and 9 inches. No clogging or blockage in the inlet and outlet piping. Trash and debris removed from bioswale. Bioswale should be re-graded and re-seeded to specification, to eliminate channeled flow. Overseeded when bare spots are evident. I • '· King County Department ofNatural Resources, 1998. King County Surface Water Design Manual. Seattle . King County Department ofNatural Resources, 1997. Lower Cedar River Basin and Nonpoint Pollution Action Plan. Seattle. King County Department of Parks, Planning, and Resources, 1990. Sensitive Areas Map Folio. Seattle. U.S. Department of Agriculture, Soil Conservation Service, 1973. Soil Survey of King County Area, Washington. Seattle. JJ-1 Evenddl Plat Preliminary 17R -June 200/ • I . '· Appendix A.I Photographs of the Downstream System Appendix A.2 Drainage Complaints Appendix A.3 Orting Hills Subbasin Map Evendell Plat Preliminary 11R-June 2001 ».::· ··~~ .. ~ I""' ~; V Photo Number 1 Date of Photo: 01/05/01 Location: Existing single-family residence in north oortion of oarcel. Description: The site currently contains one single-family residence, shed, and lawn area. $t ,.ti~·- w lJ.. I V Photo Nwnber 2 Date of Photo: 01/05/01 Location: Northwest portion of parcel, looking south. Description: Cover types on the site include mature forest, pasture, lawn, wetland, and a single-family home. Evendell.Plat -Offsite Drainage System V Photo Number 3 Date of Photo: I 01/05/01 Location: Description: Location 1 in Figure 51 looking east. A drainage ditch flows to the east along the north boundary of the site and turns south on 1 1 the site's east bound~1 . tmiilfa~ "»T-:V~:l' ~ .• V Photo Number 4 Date of Photo: Location: Description: 01/05/01 Location 8 in Figure 5, looking north. The open ditch along the east boundary of the site flows to the south along l 6oth A venue SE. -::· .·~;~.:.: Evendell Plat -Offsite Drainage System V Photo Number 5 V Photo Number 6 Date of Photo: 01/05/01 Date of Photo: 01/05/01 Location: Location 11 in Figure 5, looking south. Location: Location 33 in Figure 5, looking south. Description: After leaving the southeast comer of the site, Description: A drainage ditch flows to the south along the ditch along 160th Avenue SE continues to 156th Avenue SE. The ditch has several flow to the south. driveway and road culverts along its path. 41 Evendell Plat -Offsite Drainage System Table A.I. Summary of Downstream Drainage Complaints ;Co111p_laint . Date Property Owner Description of Complaint ?'.'~~J,~~~' 1 .. . . ·' .. ·:..··. '· .. ' . 89-0867 13802 160"' Avenue SE Drainage complaint not available. 95-0107 2/01/95 Steve Kohr Broken culvert at entrance to cul-de-sac .. 15641 SE 13 8th Place 97-0206 1/10/97 Don Gregg Offsite flows impacting private property. 16046 SE I42"d Place Backyard flooded with larger storms. Septic system operation impacted. Investigated for V Neighborhood Drainage Assistance Program. 97-0318 14038 56'" Avenue SE Flooding due to plugged culvert. Drainage complaint is a claim and is not currently available. 97-0423 14028 1601 " Avenue SE Roadside flooding -overflow of ditch along 160th A venue SE. Drainage complaint not available. 98-0202 3/19/97 Paul Huff Drainage from neighbor impacting low area of 14312 160th Avenue SE private property. t./ Evende/J Plat Preliminary 71R-.hme 200/ ,..::::· ; ' I' -I ' ·" ' . ·: . ' ' _, '-:. : -, 1-·I '.1. ' ' mLE '. ' 5 Ii ' -- i. ·-)j-. '· •. ·1 ·• .i .. :_J _·; L , -r Ir;(: ·, I -l / ~. t'._i i Drainage Complaints -From the Files of KCWLRD ,, ,, ; :t f I i" i.' r ;. 111nU eumrty Watsr and llllll HIISIIUl'C8S DMslnn -Dl'8lna!l8 Sorvlc8s Section ~Seardl Printed: 12/28100 7:36:58 AM fl CllmldaiDI : Typaal~ Addrellall'rdd8m -lbrol 1'11118 -197,4.0095 C RIPRAP 15225 JONES RO ROCKSJOIKE/15219 JONES RD/CEDAR RIV 657A4 1974..{)()96 C RIPRAP 15224 JONES RO ROCK/DIKE/JONES RO/CEDAR RIVER 657A4 1974-0103 C 15631 JONES RD SE W/0 BACKFILUJONES RO 657A4 1974-0106 C DRNG 15005 JONES RO DITCH/ALONG CEDAR 657A4 1975-0128 C FLOG 16418 SE 145TH ST STORM SEWERS/BRIARWOOD S 65784 1976-0084 C 156TH Pl SE/JONES RD DAMAGE ALONG RD/CEDAR RIVER AREA 657A4 1976-0091 C DEBRI 15463 SE JONES RO CEDAR RIVER 657A4 1979--0090 C ORNG 14406 162ND AV SE 657B3 1980-0117 C DRNG 13405 158TH AVE SE 657A2 i. 1981-0316 C 15035 SE JONES RD DIKE JETTY/CEDAR RIVER 657M ,-, 1962-0520 C FLOG 13612 160THAVE SE 65782 1982-0521 C FLOG 16426 SE 145TH Pl BRIARWOOD AREA 65764 1983--0357 C DRNG 14827 SE JONES RD CHNL OVERFLO/MADSEN CRK 657A4 1983-0386 C DRNG 15243 SE 132ND ST DRNG DITCH/SE 132ND ST/152ND AVE SE 657A2 1983-0387 C FLOG 14063 171ST AVE SE BRIARWOOD AREA 65783 1984-0224 C FLOG 16211 SE 145TH ST 65764 1985-0710 E FILL 15035 SE JONES RO KG CTY NOT RESP•WILLnotENF 657M 1986-0372 C VIOLATE 15817 SE JONES RO MOBILE HOME IN FLOOD PLAIN 657A4 1986-0372 E ILL OVLT 15817 SE JONES RD TO BALO FOR CM(CHK STAT BY CMOT). 657A4 1986-0378 C FLOG 13129 160TH AVE SE BLOCKED DITCH 65782 1986-0437 C CULVERT 15252 SE 142ND PL INSTALLATION-NEED CB 657A3 1986-0651 C FILLING 15045 SE JONES RD SEE 86-0745, 1158 657A4 1986-0745 C FILL 15045 SE JONES RO ILLEGAL FILL.CEDAR RIVER 657M 1986-0812 C EROSION 15421 SE JONES RD CEDAR RIVER 657A4 1986-1158 C FLOG 15059 SE JONES RO SEE: 86·0745 BRAMBLETT 86-0745 657A4 1987-0430 C TRFO TO SWM-FM/RO DRNG. 65782 1987-0430 ER OH/SWM DIV PLY. 65782 1987-0430 NOA OH/SWM DIV Pl Y. 65782 1987-0496 C ORNG 16423 SE 135TH ST SEEPAGE 65782 1967-0589 C SEE 87-0430 WILSON. 65782 1987-0593 C DRNG 16904 SE 136TH ST ORNG ESMT WATER/DITCH NEEDS MAINT 65782 1987-1001 X FILL 16861 SE JONES RO ILLEGAL FILL IN FLDPLAtN 65784 1988-0377 C DRNG 14250 161ST AVE SE HAZARDOUS POND OH/TO CM. 06/10189 65783 1989-0020 C FILL 13400 168TH AVE SE NEAR DRNG CHNL 65782 1989-0086 C DRNG 14820 154TH PL SE INSTALLING DRAINAGE 657A4 1989-0863 .C ORNG 13224 168TH AVE SE DITCH CLEANING/LOSING YARD 65782 1989-0867 CL DRNG 13802 160TH AVE SE CL#12735 DUE APRIL 65782 Page 1 of 4 1lTlE Drainage Complaints -From the Files of KCWLRD L I. I ,r~;{i:ks::APP~~~~J~--.••. ~~i:>·~~iitfr~ ·.~ysfrm,P~1@~!,,r'.{~:if:,••·••:;,,,,, •'.. ·i,/·:.:,,·i.·,::• Appendix B. 1 Stonnwater Facility Control and Overflow Design Appendix B.2 KCRTS Pond Design Evende/J Plat Preliminary TJR-June 2001 Evende/1 Plat Preliminary TJR-.June 2001 ,· '·· East Basin -Retention/Detention Facility Type of Facility: Side Slope: Pond Bottom Length: Pond Bottom Width: Pond Bottom Area: Top Area at 1 ft. FB: Effective Storage Depth: Stage O Elevation: Storage Volume: Riser Head: Riser Diameter: Nwnber of orifices: Orifice # Height (ft) 1 o.oo 2 5.50 3 5.90 Top Notch Weir: Outflow Rating Curve: Hyd Inflow Outflow Detention Pond 3. 00 H: lV 167. 00 ft 58 .oo ft 9686. sq. ft 23762. sq. ft 0.546 acres 7. 50 ft 452.00 ft 115676. cu. ft 2.656 ac-ft 7. 50 ft 18.00 inches 3 Full Head Diameter Discharge (in) (CFS) 1.50 0 .167 2.30 0.203 2.80 0.269 None None Peak Pipe Diameter (in) 6.0 6.0 Storage Stage Elev (Cu-Ft) (Ac-Ft) 1 3.53 1.10 7. 60 459.60 117770. 2.704 2 1. 74 0.58 7.13 459 .13 107632. 2 .471 3 2.09 a.so 6.65 458.65 97838. 2.246 4 1. 74 0.46 6.47 458.47 94092. 2.160 5 1. 84 0.21 5. 72 457. 72 79774. 1. 831 6 1. 50 0.11 3.30 455.30 39784. o. 913 7 1. 40 0.13 4.41 456.41 568 65. 1.305 8 1. 09 0.14 5 .11 457 .11 68 64 7. 1.576 Hyd R/D Facility Tributary Reservoir POC Outflow Outflow Inflow Inflow Target Cale 1 1.10 0.16 ******** ******* 1.13 2 0.58 0.08 ******** ******* 0.61 3 0.50 0.09 ******** ******* 0.52 4 0.46 0.08 ******** ******* 0.47 5 0.21 0.09 ******** ******* .0.21 6 0.11 0.08 ******** ******* 0.18 7 0.13 0.07 ******** ******* 0.18 8 0.14 0.05 ******** ""****** 0.17 Evende/1 Pim Preliminary 1JR-June 2001 West Basin -Retention/Detention Facility Type of Facility: Facility Length: Facility Width: Facility Area: Effective Storage Depth: Stage O Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Orifice # Height (ft) 1 0.00 2 4.75 Top Notch Weir: Length: Weir Height: Outflow Rating Curve: Hyd Inflow Outflow Detention Vault 80.00 ft 25.00 ft 2000. sq. ft 9. 00 ft 470.00 ft 18000. cu. ft 9. 00 ft 12. 00 inches 2 Full Head Diameter Discharge (in) (CFS) 0.70 0.040 1.30 0.094 Rectangular 3.00 in 8.90 ft None Peak Pipe Diameter (in) 4.0 Storage Stage Elev (Cu-Ft) (Ac-Ft) 1 0.60 0.15 8.96 478. 96 2 0.29 0.11 7. 61 4 77. 61 3 0.30 0.10 6. 91 476.91 4 0.31 0.08 6.00 476.00 5 0.35 0.09 6.07 476.07 6 0.26 0.02 3 .11 4 73 .11 7 0.31 0.02 2.40 472.40 8 0.24 0.03 3. 97 473.97 Hyd R/D Facility Tributary Reservoir Outflow Inflow Inflow 1 0.15 0.09 ******** 2 0.11 0.05 ******** 3 0.10 0.05 ******** 4 0.08 0.05 ******** 5 0.09 0.05 ******** 6 0.02 0.05 ******** 7 0.02 0.06 ******** 8 0.03 0.04 ******** Route Time Series through Facility Inflow Time Series File:devwest.tsf Outflow Time Series File:rdoutw POC Time Series File:pocwest Inflow/Outflow Analysis Peak Inflow Discharge: Peak Outflow Discharge: Peak Reservoir Stage: Peak Reservoir Elev: 0.595 0.146 8.96 478.96 CFS CFS Ft Ft 17 921. 15219. 13815. 12009. 12133. 6214. 4797. 7942. POC Outflow Target Cale ******* 0. 20 ******* 0.14 ******* 0.13 ******* 0 .11 ******* 0.11 ******* 0. 07 ******* 0. 07 ******* 0. 06 at 6:00 on Jan at 11: 00 on Jan Peak Reservoir Storage: 17921. Cu-Ft o. 411 Ac-Ft Evendell Plat Preliminary 17R-June 2001 0.411 0. 34 9 0.317 0.276 0.279 0.143 0.110 0.182 9 in 9 in Year 8 Year 8 I Appendix C.1 Storrnwater System Conveyance Appendix C.2 KCRTS Time Series Calculations Appendix C.3 KCRTS Peak Flow Rates Evendell Plat Preliminary TJR-June 2001 Loading Time Series File:bywest.tsf Computing Interval L6cations Computing Flow Durations Durations & Exceedence Probabilities to File:bywest.dur Evende/1 Plat Preliminary 71R-June 2001 Analysis Tools Command RETURN to Previous Menu KCRTS Command eXit KCRTS Program ffl ~ • ri ~ r r, • • ~ • • ff' .; ~ Flow Frequency Analysis Time Series File:exeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.645 2 2/09/01 18:00 0.200 7 1/05/02 16:00 0.517 3 2/28/03 3:00 0.037 8 3/24/04 19:00 0.303 6 1/05/05 8:00 0.508 4 1/18/06 20:00 0.457 5 11/24 /06 4:00 0.891 1 1/09/08 9:00 Computed Peaks Flow Frequency Analysis Time Series File:exwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.138 2 2/09/01 18:00 0.059 7 1/05/02 16:00 0.129 3 2/28/03 3:00 0.024 8 8/26/04 2:00 0.074 6 1/05/05 8:00 0.122 4 1/18/06 16:00 0.116 5 11/24 /06 4:00 0.235 1 1/09/08 6:00 Computed Peaks Flow Frequency Analysis Time Series File:deveast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 1. 74 6 2/09/01 2:00 1. 40 8 1/05/02 16: 00 2.09 3 2/27/03 7:00 1. 50 7 8/26/04 2:00 1. 80 5 10/28/04 16: 00 . 1. 84 4 1/18/06 16:00 2.17 2 10/26/06 0:00 3.53 1 1/09/08 6:00 Computed Peaks Evemldl Plat Preliminary 11R-June 20()/ -----Flow Frequency Analysis------- --Peaks Rank Return Prob ·(CFS) Period _0.891 1 100.00 o·.645 2 25.00 0.517 3 10.00 0.508 4 5.00 0.457 5 3.00 0.303 6 2.00. 0.200 7 1.30 0.037 8 1.10 0.809 50.00 0.990 0. 960 0.900 0.800 0. 667 0.500 0.231 0.091 0.980 -----Flow Frequency Analysis------- -Peaks Rank Return Prob (CFS) Period 0.235 1 100.00 0.990 0.138 2 25.00 0.960 0 .129 3 10.00 0.900 0.122 4 5.00 0.800 0.116 5 3.00 0.667 0.074 6 2.00 0.500 0.059 7 1. 30 0.231 0.024 8 1.10 0.091 0.202 50.00 0.980 -----Flow Frequency Analysis------- -Peaks Rank Return Prob .(CFS) Period 3.53 1 100.00 0.990 2.17 2 25.00 0.960 2.09 3 10.00 0.900 1. 84 4 5.00 0.800 1.80 5 3.00 0.667 1. 74 6 2.00 0.500 1. 50 7 1.30 0.231 1. 40 8 1.10 0.091 3.08 50.00 0.980 Flow Frequency Analysis Time Series File:devwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0. 294 6 2/09/01 2:00 0.240 8 1/05/02 16:00 0.354 3 2/27/03 7:00 0 .260 7 8/26/04 2:·00 0. 313 4 10/28/04 16: 00 0.312 5 1/18/06 16:00 0.378 2 10/26/06 0:00 0.595 1 1/09/08 6:00 Computed Peaks Flow Frequency Analysis Time Series File:byeast.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.080 7 2/09/01 2:00 0.070 8 1/05/02 16: 00 0.098 3 12/08/02 18:00 0.082 6 8/26/04 2:00 0.097 4 10/28/04 16:00 0.085 5 1/18/06 16: 00 0.120 2 10/26/06 0:00 0.156 1 1/09/08 6:00 Computed Peaks Flow Frequency Analysis Time Series File:bywest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.046 7 2/09/01 2:00 0.040 8 1/05/02 16:00 0.056 3 12/08/02 18:00 0.047 6 8/26/04 2:00 0.056 4 10/28/04 16:00 0.049 5 1/18/06 16:00 0.069 2 10/26/06 0:00 0.090 1 1/09/08 6:00 Computed Peaks E vende/1 PUii Preliminary 11R -June 200 I -----Flow Frequency Analysis------- -Peaks Rank Return Prob (CFS) Period 0.595 1 100.00 0.990 0.378 2 25.00 0. 960 0.354 3 10.00 0.900 0.313 4 5.00 0.800 0.312 5 3.00 0.667 o; 294 6 2.00 0.500 0.260 7 1.30 0.231 0.240 8 1.10 0.091 0.523 50.00 0. 980 -----Flow Frequency Analysis--~---- -Peaks Rank Return Prob (CFS) Period 0.156 1 100.00 0.990 0.120 2 25.00 0.960 0. 098 3 10.00 0.900 0.097 4 5.00 0.800 0.085 5 3.00 0. 667 0.082 6 2.00 0.500 0.080 7 1. 30 0.231 0.070 8 1.10 0.091 0.144 50.00 0.980 -----Flow Frequency Analysis------- -Peaks Rank Return Prob (CFS) Period 0.090 1 100.00 0.990 0.069 2 25.00 o. 960 0.056 3 10.00 0. 900 0.056 4 5.00 0.800 0.049 . 5 3.00 0. 667 0. 047 6 2.00 0.500 0.046 7 1.30 0.231 0.040 8 1.10 0.091 0.083 50.00 0. 980 ~ & p p Flow Frequency Analysis • Time Series File:poceast.tsf Project Location:Sea-Tac .. D ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0. 611 2 2/09/01 19:00 0.177 7 1/05/02 16:00 0.517 3 3/06/03 20:00 0.182 6 8/26/04 2:00 p 0.173 8 1/05/05 8:00 0.214 5 1/19/06 2:00 0.472 4 11/24/06 6:.00 1.13 1 1/09/08 11:00 I Computed Peaks Flow Frequency Analysis Time Series File:pocwest.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank Time of Peak (CFS) 0.140 2 2/09/01 18:00 0.059 8 1/05/02 16:00 '· 0.110 4 3/06/03 19:00 0. 067 7 8/26/04 2:00 0.068 6 10/28/04 16:00 0.107 5 1/18/06 20:00 '· 0.135 3 11/24/06 4:00 0.197 1 1/09/08 9:00 Computed Peaks Evendell Plat Preliminary TJR-June 2001 -----Flow Frequency Analysis------- --Peaks Rank Return Prob (CFS) Period 1.13 1 100.00 0.611 2 25.00 0.517 3 10.00 0.472 4 5.00 0.214 5 3.00 0.182 6 2.00 0.177 7 1.30 0.173 8 1.10 0.955 50.00 0.990 0. 960 0.900 0.800 0. 667 0.500 0.231 0.091 0.980 -----Flow Frequency Analysis~------ -Peaks Rank Return Prob (CFS) Period 0.197 1 100.00 0 .. 990 0.140 2 25.00 0.960 0.135 3 10.00 0.900 0.110 4 5.00 0.800 0.107 5 3.00 0.667 0.068 6 2.00 0.500 0 .067 7 1. 30 0.231 0.059 8 1.10 0. 091 0 .178 50.00 0.980 b • ;,/ .::i{%:i>Pl!i4!i.:i.t')!r4i!!i!~giffil9.~~Lifii~#m:~i:ft?:ti~i,i\S·?;?l::.}> :/\\'i·ffi\Q;;fi!CfiL;,;;e;:·:;)f:t • The following is a description of KCRTS input and output files used in designing the R/D facilities and conducting the downstream drainage analysis for the Evendell Plat. EXECUTABLE FILES basins.exc: This executable file creates time series for all contributing areas to P the downstream system. tar.exc: This executable creates target duration files for RID design. b. TIME SERIES FILES D R/D Design D • • D p exeast.tsf: The site's easterly basin under existing conditions. Includes area of proposed road improvements along SE 136th Street. exwest.tsf: The site's westerly basin under existing conditions. Includes area of proposed road improvements along SE 136th Street. byeast.tsf: The portion of proposed road improvements along SE 136th Street in the easterly basin that bypasses the stormwater facility. bywest.tsf: The portion of proposed road improvements along SE 136th Street .in the westerly basin that bypasses the stormwater facility. deveast.tsf: The site's easterly basin under proposed developed conditions. • Includes area of proposed road improvements along SE 136th Street. D devwest.tsf: The site's westerly basin under proposed developed conditions. Includes area of proposed road improvements along SE 136th Street. poceast.tsf: Time series for developed conditions at the site's easterly downstream point-of-compliance. pocwest.tsf: Time series for developed conditions at the site's westerly downstream point-of-compliance. Evendell Plat Preliminary 11R-June 2001 tare.tsf: Target duration easterly basin. tarw.tsf: Target duration westerly basin. RESERVOIRS rdeas.rdf: curve for the Based on the curve for the Based on the proposed R/D system ~or the site's following times series: exeast.tsf. proposed R/D system for the site's following times series: exwest. ts f. The Evendell Plat R/D facility managing stormwater from the easterly basin of the developed site, including an offsite road improvements. rdwes.rdf: The Evendell Plat R/D facility managing stormwater from the westerly basin of the developed site, including an offsite road improvements. GENERAL NOTES 1. Seatac regional rainfall runoff files with a scale factor of 1.0 were used in the hydrologic simulations. '.1. R/D facilities were designed with the 8-year data set. 1-hour peak flow rates were used for detention calculations. 3. 15-minute peak flow rates were used for conveyance calculations. 4. Gravel areas were modeled in KCRTS by assuming that 50 percent of the area is impervious and the remaining .50 percent are the same cover type as that surrounding the gravel area. EvendeU PlatPrelimintuy T1R-JWJe 2001 ~ r fF: ~ 01 (IF tfll: r ~ ~ ~ ~ ~ ~ ~ "<il 'Ii JEvendell Plat Level 3 Downstream Drainage Analysis !EXPIRES: Submitted 10: King County DOES 900 O.akesdale A venue S. W. Renton, WA 98055 Prepared by: Haozous Engineering, P.S. 9957 !71~ Avenue SE Renton, WA 98059 Tel. (425) 235-2707 Fa, (425) 254-0579 August 26, 2002 -1 ,, " /ff ,,, fJ I " " " r I n g , 9957 171u Avenue SE Jax (425) 254-0579 _ August 26. 2002 Mr. Michael Romano Renton, WA 98059 (425) 235-2707, Centurion Development Services 22617 8th Drive SE Bothell, WA 98021 Re: Evendell Plat -Level 3 Downstream Drainage Analysis DOES File No. Dear Mr. Romano: §>. s. This letter report documents the methods and results of a Level 3 Downstream Drainage Analysis requested by DDES for the Evendell Plat. Separate analyses were conducted for the two drainage courses from the Evendell site. Project Description The Evendell Plat is a proposed residential development located within the Renton Highlands area of unincorporated King County (Figure l ). The proposal for development includes building single-family dwellings on approximately 12 acres (Haozous Engineering, June 2001)-Road improvements along SE l36'h Street are also proposed. Level 2 RID standards are being proposed for the onsite stormwater facility as is required by the King County Flow Application Maps and recommended by Lower Cedar River Basin and Nonpoint Action Plan. Site Description The site is located within the Orting Hills subbasin of the Cedar River watershed (King County Department ofNatural Resources, 1999). The site is located east of 156 1h Avenue SE and is bordered by SE 1361h Street on the north and by 1601h A venue SE on the east. Cover types on the site include a single-family residence, pasture, and forest. A Class 2 wetland has been identified in' the northeast portion of the site. The site consists of two basins with most of the project area draining to the easterly basin. The easterly basin drains to a conveyance system along 1601h A venue SE. The westerly basin drains to a conveyance system along 1561h Avenue SE. Both downstream drainage courses eventually discharge to an unclassified tributary of the Cedar River (King County Department of Parks, Planning, and Resources, 1990). Drainage Complaints Drainage complaints along the downstream systems were investigated at King County Water and Land Resource Division as part of the Level l Downstream Drainage Analysis submitted with the project's preliminary technical information report (TIR)(Haozous Engineering, June 2001 ). Since the preliminary TIR was prepared, neighborhood comment fonns, collected by C.A.R.E., have been reviewed for information about drainage-related problems in the basins. Ofparticular note, flooding from the ditch on the east boundary of the Evendell site has been observed by Mr. Bret Bowden, a resident at 13814 160th A veriue SE. When flooding occurs, water crosses the road and flows onto Mr. Bowden's property. Mr. Don Gregg, a resident at 16046 SE 142"d Place, has also observed portions of 160th Avenue SE inundated by flooding during the past 5 years. Methodology A hydraulic analysis was conducted for conveyance systems along both 160th A venue SE and 1561h Avenue SE. The conveyance system along 1601h Avenue SE was evaluated from the east boundary of the site for a distance of 2,300 feet. The conveyance system along 156th A venue SE was evaluated from a location due west of the site for a distance of 1,900 feet. Both systems consist of driveway culverts, pipe segments, and open channel. The model Stormshed™ was used to predict runoff rates from contributing basins and to model the hydraulics of the conveyance systems. Stormshed™ is widely applied in similar projects and has been adopted by Washington State Department of Transportation for assessing and designing highway conveyance systems. A field survey of the downstream systems was conducted by a licensed surveyor. Ditch cross sections, pipe inverts, catch basin rims, and road surface elevations were surveyed to obtain data for the Stormshed™ hydraulic model. A summary of each structure surveyed is provided in Table l. Basin boundaries contributing to the conveyance system were based on aerial topography and the Cedar River Basin Plan. The basin boundaries were field-verified and divided into subbasins contributing to various branches of the conveyance system (Figure 2). The easterly basin was divided into seven subbasins (el -e7), ranging from I .I to 33.9 acres in size (Table 2). The westerly basin was divided into eight subbasins ( w 1 -w8), ranging from 1.2 to 16.3 acres in size. Cover types and land uses in the subbasins were based on a 1990 aerial photograph and updated for recent development by conducting a field reconnaissance. The basins consist of mostly single-family residential land use with housing densities ranging from about J to 6 dwelling units per acre. Land uses and cover types are shown in Figure 3. The east basin was estimated to have a total of 124.4 acres, with 35.6 acres in forest, 20.2 in 2 pasture, and 68. 7 acres in single-family residential land use (Table 3). The west basin was estimated to have a total of 48.3 acres, with 6.5 acres in forest, 7 .0 in pasture, and 33.4 acres in single-family residential la'nd use, and I .4 acres occupied by a church. Based on King County Soil Survey (U.S. Department of Agriculture, 1973) soil types in the basins consist of Alderwood soils. · The Santa Barbara Urban Hydrograph (SBUH) model was used to model the runoff from each of the subbasins contributing to the conveyance systems. Curve numbers for the subbasins were based on the weighted averages of the various land uses in the watershed (Table 4). Hydro graphs for the 2-, I 0-, 25-, 50-, and I 00-year storms were routed through the Stormshed™ hydraulic model of the conveyance systems to determine flooding locations and their approximate return periods. The Evendell site and other contributing areas in the basins were modeled under their existing land use conditions. Travel paths for each subbasin were based on aerial topography. The type of flow, flow length, and slope used to calculate time-of-concentrations are summarized in Table 5. Rainfall amounts of2.0, 3.0, 3.5, 3.75, and 4.0 inches were used for the 2-, JO-, 25-, 50-, and JOO-year storms design storms in the SBUH model. Modeling Results Details of each subbasin modeled in Stormshed are presented in Appendix A. I for the easterly basin and in Appendix A.2 for the westerly basin. Model results for routing the design storm hydrographs through the drainage networks are presented in Tables B. I through B.12 of Appendix B. Table 6 presents a summary of flow rates at key locations in each of the conveyance systems. A summary of predicted flooding, for all surveyed structures, including open channels, is provided in Table B.6 for the easterly basin and in Table B.12 for the westerly basin. The locations and return periods of flooding related to pipes and culverts are identified in Figure 4. Many of the driveway culverts and pipes along 160th A venue SE flood at a return period of2-years (Table B.6 and Figure 4). Several reaches of ditch also overtop at this return period, likely as a result of constrictions in the pipe capacities. Modeling results are consistent with drainage complaints from residents along this reach of the drainage course. Similar modeling results were obtained for the westerly drainage course, where several culverts and catch basins were predicted to overtop at 2-year or I 0-year return periods (Table B.12 and Figure 4). Conclusions Several flooding locations with return periods of 2°years were identified in the downstream conveyance systems. Flooding in the east basin that overtops and inundates 1601h Avenue SE is considered a severe road flooding problem by the King County 3 . ·l Surface Water Drainage Manual. Residential structures have been flooded at 14028 160th Avenue SE and at 16046 SE 142nd Place. If the finished space or the electrical/heating components of these residential structures were flooded in the past, the flooding would be classified as a severe problem. Otherwise, flooding that occurs at these residences is considered a nuisance problem. Channel erosion observed along the east boundary of the nd . property at 16046 SE 142 Place, downstream from Pipe P-110, has been a persistent problem over the past several years and would likely be considered a severe erosion problem. Continued bank erosion is likely at this location, with potential for reducing the capacity of channel sections further downstream where sediment is deposited. The flooding that occurs at the adjacent residence is likely related to the reduction in channel capacity due to sediment deposition from the eroded banks. Based on modeling results and information available, flooding problems in the westerly basin would likely be classified as nuisance problems by the King County Surface Water Drainage Ma,mal (1998). We found no documentation indicating that 1561h Avenue SE or residential structures along the westerly drainage course have flooded in the past. However, a drainage complaint (Complaint No. 97-0318) related to flooding due to a plugged culvert, was not available for review (Haozous Engineering, June 2001). Proposed Mitigations Level 2 RID standards are currently being proposed for new development in the westerly basin of the Evendell Plat. No additional flow control or other mitigations are therefore required in this basin to reduce project impacts to nuisance flooding problems. Level 2 RID standards are also currently being proposed for new development in the easterly basin of the Evendell Plat. With severe flooding and severe erosion problems located in the downstream drainage course, additional measures to mitigate drainage impacts could be required. For the severe road flooding problem along 1601h Avenue SE either of the following mitigations could be required: • Providing Level 3 detention in the easterly basin, OR • Upgrading the downstream conveyance system along 1601h Avenue SE to eliminate road flooding. This would likely entail replacing driveway culverts P-117 and P- 116 on the west side of 1601h Avenue SE, cross culvert P-115, and pipes P-114 and P-113 on the east side of 1601h Avenue SE (Figure 4). For the severe erosion problem along the east boundary of the property at 16046 SE 142"" Place, the Level 2 RID standards provide the mitigation required by code. Other types of mitigations to reduce erosion at this location, such as bank stabilization in the eroded section of channel or Level 3 RID standards, can be imposed through the King County Surface Water Drainage Manual under certain circumstances. It is our opinion that either stabilizing the eroding section of channel or the use of Level 3 RID standards would mitigate project-related drainage impacts that occur at this location. 4 . ·I If you have questions regarding these analyses or need additional documentation, please do not hesitate to call me. Sincerely, Edward McCarthy, Ph.D. P.E. Hydrologist 5 , .. , References Haozous Engineering, June 15, 2001. Evendell Plat -Preliminary Technical Information Report. Renton, Wash. · King County Department ofNatural Resources, 1998. King County Surface Water Design Manual. Seattle. King County Department of Natural Resources, 1997. Lower Cedar River Basin and Nonpoint Pollution Action Plan. Seattle. King County Department of Parks, Planning, and Resources, 1990. Sensitive Areas Map Folio. Seattle. U.S. Department of Agriculture, Soil Conservation Service, 1973. Soil Survey of King County Area, Washington. Seattle. 6 . ·I Table 1 (continued) Reach ID Reach Pipe Dia. Manning's Length UpstrlE Dwnst IE Slope Type (IN) n . (FT) (FT) (Ff) (O/o) West Basin P-001 Circular 12 0.013 113 378.62 372.66 5.27 D-001 X-Section 0.035 3 379.22 378.62 20.00 D-002 X-Section 0.035 114 381.68 379.22 2.16 D-003 X-Section 0.035 153 388.9 381.68 4.72 D-004 X-Section 0.035 157 397.4 388.9 5.41 D-005 X-Section 0.035 2 396.77 397.4 -31.50 P-002 Circular 12 0.013 25 397.51 396.77 2.96 D-006 X-Section 0.035 3 398.49 397.51 32.67 D-007 X-Section 0.035 35 399.58 398.49 3.11 P-003 Circular 12 0.013 19 400.17 399.58 3.11 D-008 X-Section 0.035 2 400.4 400.17 11.50 D-009 X-Section 0.035 36 400.91 400.4 1.42 P-004 Circular 12 0.013 59 403.71 400.91 4.75 P-005 Circular 12 0.013 9 404.21 403.51 7.78 P-006 Circular 12 0.013 42 406.09 404.26 4.36 P-007 Circular 12 0.013 150 411.17 406.34 3.22 P-008 Circular 12 0.013 157 417.58 411.77 3.70 P-008A Circular 12 0.013 28 418.1 417.58 1.86 P-009 Circular 12 0.013 142 427.25 420.75 4.58 P-010 Circular 12 0.013 86 431.9 427.35 5.29 P-011 Circular 12 0.013 62 434.34 432 3.77 P-012 Circular 12 0.013 33 435.68 434.39 3.91 D-010 X-Section 0.035 3 436.07 435.68 13.00 D-011 X-Section 0.035 48 438.87 436.07 5.83 D-012 X-Section 0.035 53 442.78 438.87 7.38 P-013 Circular 12 0.013 19 444.46 442.78 8.84 D-014 X-Section 0.035 3 444.63 444.46 5.67 D-015 X-Section 0.035 43 446.52 444.63 4.40 P-014 Circular 12 0.013 23 447.67 446.52 5.00 D-016 X-Section 0.035 3 448.08 447.67 13.67 D-017 X-Section 0.035 57 450.3 448.08 3.89 P-015 Circular 12 0.013 22 451.33 450.3 4.68 D-018 X-Section 0.035 3 451.83 451.33 16.67 D-019 X-Section 0.035 52 454.6 451.83 5.33 P-016 Circular 12 0.013 34 457.55 454.6 8.68 D-020 X-Section 0.035 3 457.71 457.55 5.33 D-021 X-Section 0.035 107 465.05 457.71 6.86 Table 2. Summary of Existing Basin Cover Types by Subbasin Curve Number= Subbasin East Basin . el e2 e3 e4 e5 e6 e7 Site -East Subtotal West Basin wl w2 w3 w4 w5 w6 w7 w8 Site - West Subtotal 81 0 85 0 Till-forest Till-pasture (AC} (AC} -5.8 6.0 5.2 -1.7 -- 4.0 1.8 14.9 3.5 1.8 - 8.9 2.2 35.6 20.2 -- -0.7 -- -- -- 0.8 - 1.6 - 3.8 4.9 0.4 1.4 6.6 7.0 98 0 86 0 98 0 Cover Type Wetland Till-grass Imperv (,4C) (AC) (,4C) 12.0 1.9 15.6 7.0 0.7 0.1 0.9 0.2 12.3 5.4 9.8 2.3 -- 0.4 -O.l 0.4 51.4 16.9 2.3 0.6 13.8 1.8 1.0 0.2 2.7 0.5 1.8 0.4 1.8 1.3 3.8 2.4 0.4 0.0 --0.1 -27.6 7.2 Total (AC) 19.7 33.9 2.4 I.I 23.5 30.4 1.8 11.6 124.5 2.9 16.3 1.2 3.2 2.2 3.8 7.8 9.1 1.9 48.4 .·l Table 4. Curve Numbers for Subbasius Subbasin Pervious Pervious Jmperv CN (AC} (,4C) East Basin el 85.7 17.8 1.9 e2 84.7 26.9 7.0 e3 85.3 2.3 0.1 e4 86.0 .0.9 0.2 e5 84.8 18.1 5.4 e6 83.2 28.1 2.3 e7 81.0 1.8 - Site -East 81.8 I I.I 0.5 West Basin wl 86.0 2.3 0.6 w2 86.0 14.5 1.8 w3 86.0 1.0 0.2 w4 86.0 2.7 0.5 w5 86.0 1.8 0.4 w6 84.5 2.5 1.3 w7 84.5 5.4 2.4 w8 83.4 9.0 0.0 Site - West 84.0 1.8 0.1 .·1 Table 5. Travel Path Distances and Slopes for Pervious Land Areas Sheet Flow Delta Shallow Flow Delta Channel Flow . Delta Subbasin Distance Elev. Slope Distance Elev. Slope Distance Elev. Slope (FI) (FI) (FT/Fl) (Fl) (Fl) (FT/Fl) (Fl) (FI) (FT/Fl) East Basin el 300.0 5.0 0.017 1,484.0 20.0 0.013 950.0 10.0 0.011 e2 300.0 5.0 0.017 922.0 15.0 0.016 1,824.0 18.0 0.010 e3 300.0 5.0 0.017 264.0 3.0 0.011 106.0 3.0 0.028 . e4 300.0 5.0 0.017 200.0 4.0 0.020 e5 300.0 8.0 0.027 1,248.0 23.0 0.018 705.0 10.0 0.014 e6 300.0 3.0 0.010 1,777.0 35.0. 0.020 e7 300.0 3.0 0.010 Site -East 300.0 3.0 0.010 876.0 13.0 0.015 West Basin wl 2,610.0 70.0 .0.027 w2 300.0 5.0 0.017 585.0 70.0 0.120 w3 300.0 32.0 0.107 272.0 13.0 0.048 w4 300.0 10.0 0.033 292.0 22.0 0.075 w5 300.0 30.0 0.100 322.0 22.0 0.068 w6 300.0 2.0 0.007 613.0 40.0 0.065 w7 300.0 20.0 0.067 655.0 40.0 0.061 w8 300.0 20.0 0.067 1,020.0 70.0 0.069 Site - West 210.0 10.0 0.048 .... ..:.. Table 3. Summary of Land Uses by Subbasin Subbasin East Basin el e2 e3 e4 e5 e6 e7 Site -East Total West Basin wl w2 w3 w4 w5 w6 w7 w8 Site -West Total % Grass % lm_JJ_erv Forest Pasture (AC) (,4C) -5.8 6.0 5.2 -l.7 -- 4.0 1.8 14.9 3.5 1.8 - 8.9 2.2 35.6 . 20.2 -- -0.7 -- -- -- 0.8 - 1.6 . - 3.8 4.9 0.4 1.4 6.5 7.0 92.5% 7.5% SFJ (AC) 4.5 2.1 0.8 - - 4.7 - 0.1 12.1 - 14.5 - - - - 0.6 0.4 0.1 15.6 83.5% 16.5% SF2 (AC) 9.5 6.7 - l. l 7.9 4.5 - 29.8 2.6 - 1.2 3.2 2.2 - - - 9.2 58.4% 41.6% SF6 (AC) - 13.8 - - 9.8 2.8 - 26.4 - - - - - 3.0 5.6 - 8.6 0.0% 100.0% Wetland (AC) 0.4 Notes: SF!= Single-family residential with I DU/Ac; SF2 = 2 DU/Ac; SF6 = 6 DU/Ac 36.0% 64.0% Church (AC) - - - - - - - - 0.3 1.1 - - - - - - 1.4 . Total (AC) 19.7 33.9 2.4 I. I 23.5 30.4 . 1.8 11.6 124.4 2.9 16.3 1.2 3.2 2.2 3.8 7.8 9.1 1.9 48.3 Table 1. Sumary of Surveyed Structures in Downstream System , Reach JD Reach Pipe Dia. Manning's Length Upstr IE Dwnst IE Slope. Type (IN) n (FT) (FT) (FT) (%) East Basin D-110 X-Scction 0.035 48 408.54 407.59 1.99 D-111 X-Scction 0.035 58 409.57 408.54 1.78 D-112 X-Section 0.035 20 411.25 409.57 8.57 D-113 X-Section 0.035 12 411.86 411.25 5.28 D-114 X-Section 0.035 48 412.96 411.86 2.31 P-110 Circular 24 0.010 60 413.6 412.96 1.06 D-115 X-Section 0.035 3 414.27 413.6 25.24 D-116 X-Scction 0.035 33 415.1 414.27 2.48 D-117 X-Section 0.035 24 415.34 415.l 1.01 . D~ll8 X-Section 0.035 25 417.07 415.34 7.01 D-119 X-Section 0.035 48 419.77 417.07 5.61 D-120 X-Section 0.035 79 420.05 419.77 0.35 P-111 Circular 18 0.013 29 419.3 420.05 -2.56 D-121 X-Section 0.035 6 421.94 419.3 45.68 D-122 X-Scction 0.035 24 422.17 421.94 0.96 P-112 Circular 12 0.013 85 423.42 422.17 1.47 D-123 X-Section 0.035 43 424.16 423.42 J.73 D-124 X-Scction 0.065 90 424.6 424.16 0.49 D-125 X-Section 0.065 107 426.13 424.6 1.43. D-126 X-Section 0.065 48 428.17 426.13 4.27 D-127 X-Section 0.035 79 429.74 428.17 1.99 D-128 X-Section 0.035 56 431.36 429.74 2.87 P-113 Circular 18 0.01 124 434.95 431.36 2.91 D-129 X-Section 0.035 12 434.81 434.95 -1.21 D-130 X-Section 0.035 61 436.28 434.81 2.40 D-131 X-Section 0.035 66 439.1 436.28 4.30 P-114 Circular 24 0.024 21 439.59 439.1 2.37 D-132 X-Section 0.035 JO 440.26 439.59 7.02 P-115 Circular 12 0.013 45 441.31 439.59 3.78 D-133 X-Scction 0.035 2 441. 15 441.31 -7.30 D-133A X-Section 0.035 35 442.14 441.15 2.80 D-134 X-Section 0.035 50 443.4 442.14 2.53 D-135 X-Section 0.035 106 444.67 443.4 1.20 0-136 X-Section 0.035 54 445.89 444.67 2.25 P-116 Circular 18 0.024 28 446.34 445.89 I.62 D-137 X-Section 0.035 3 . 446.6 446.34 10.15 0-138 X-Section 0.035 88 448.4 446.6 2.04 D-139 . X-Section 0.035 106 451.13 448.4 2.58 D-140 X-Section 0.035 55 452.3 451.13 2.15 P-117 Circular 12 0.013 18 452.9 452.3 3.39 D-141 X-Section 0.035 3 452.65 452.9 -9.42 D-142 X-Section 0.035 102 454.76 452.65 2.07 D-143 X-Section 0.035 160 459.46 454.76 2.93 D-144 X-Section 0.035 103 462.79 459.46 3.24 D-145 X-Section 0.035 !00 466.72 462.79 3.92 ' Table 6 Peak Flow Rates at Selected Locations . . . Storm Return Period Location 2-Year JO-year 25-Year 50-Year JOO-Year (CFS) (CFS) (CFS) (CFS) (CFS) East Basin P-110 12.0 24.5 31.6 3.5.3 38.9 P-111 12.1 24.9 32.0 35.6 39.4 P-112 9.9 20.0 25.5 28.3 31.2 P-113 10.2 20.3 25.9 28.7 31.6 P-114 10.2 20:4 25.9 28.8 31.7 P-115 7.4 15.2 19.4 21.6 23.8 P-116 7.3 14.9 19.1 21.2 23.4 West Basin P-001 6.8 13.7 17.5 19.4 21.2 P-002 6.2 12.2 15.4 17.0 18.6 P-006 4.8 9.6 12.2 13.5 14.7 P-008A 4.1 8.4 10.8 . 11.9 13.1 P-009 3.8 7.7 9.8 10.9 11.9 P-013 3.2 6.7 8.5 9.4 10.4 P-015 3.0 6.2 8.0 8.8 9.7 P-016 2.8 5.7 7.3 8.1 8.9 Note: Flow rates are those predicted by Stormshed using the SBUH method. .·l ::, 0 • 0 C .. ~ :~ !: . ·eta_~)\, J). ·, \ o• 167 ~ SOURCE: USGS 7.5 x 15 Minute Series -Renton, Washington SCALE: 1 :25 000 Tlll.E PAGE Figure 1. Vicinity Map DATE 1-5 01/03/01 ,uu ~DO ..• :. 4 1 .,.do· ·#-ifij SCALC IN rtET ,. ) -- ,---"" \"" ,: I , .J . ] \ ..• I 11 i \\ I: 1• ,i; /\ / ~ ',,,. ~ .... ) u 'I" I' \,. t 11. 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' ,·~·-, _,. . .,..'.-,("""')("", !//'' '"·:·~.-.,.,.~,.'.;?~,~~::(~··: ' ···:ca.L ·1: i<'• '-til > ,.._,):,. ,!u . 451;, ·~:· (:; ;1,:. e6 '\.,, C w, .. ~.' I"/ '' ' •''•'\ !"''''!, ~~:.;, ~.,., .. /' ...... , .(,,. <""\ ;) \ r·; SITE IS 9% OF TRIBUTARY AREA PROJECT NO. Haozous Engineering CIVJL ENGIIEERING EVENDELL PLAT. l!I ll:fll 1'1-816 SE U6TH ST, RENTON, IJA 98059 425-235-2707 -·· .. ,.. £'.JM S/12/02 ....... DATO E:JM S/12/02 rfGlJRE Drainage Basins 2 • ... .... SCM.£ 1H FIJ:T LEGEND a CQ tch BQsln PS Pipe ID ~0-YeQr ! Floocllng Return Perlocl ,. a . -······-~l·-··1:~···::::·::.·~·-" "} ;j i: .::\ i ,:') :: .l j'i ,, 'l ( I . P15 1/ . •·•· P16t;~ ·· ".' ~~~ :1:: ', . J~O-YeQ~T··~: P121:I, , · . . , I '"' PU-'.• ··· .... , ....• ,,, Pl :.:: .. · . ~25-Yeo.1 L ,. '·:.,.:· .... ':'"'' .. .'.;.;: .. : .... ,;{'.:Jt ·'. U fl F.' , "I ,,, ~ P7 P6 .• -!i ';·.-· P117 n, p«--llt,· .. ·· I P4 ·tt .... . , I . .'.. . . 1 ·• P116 Pl J/ ··1' , P115 .,, .. i·;· !2-Yeo,r j \) ·.'// ., '! it;: ;;;tr;,,:];,· io '·i[/ '"1ll'<"'I i,-1 \;, Ci; 11 ;1·: ·i <i ! .i) ~ f 1 ~I , l ···----.. --... -,----.-··-----_,: s-i (l?: : .. : ,_'J,:'''' I Haozous llm.gineering CML D!lilkWdlG 14816 8E 116TH IT, IElffllX. \IA ta99 42J.8ZI C,GI D[SIGliED UY: """ w Q/12/111 ORA-. D~ w DATE: 11,111/111 r , ~.\\'• :: "fl· 1.·.1·:,: '• I . 1~-YeQr I ......•...• \!.• ... ;"·. -, 12,,,YeQr\ I P110f\\ 110-YeQr I :_ r,;~( ·i CJ· lii,11 .;{]\;t,· ~ Ul,\I t I ' / •• , ' '.. \, ~i i • EVENDELL PLAT Flooding Locations· PROJECT NO. FIGURE 4 200 400 ,} ,Q .Pi-) SCAt.£ IN F'[tl Haozous Engineering CIVIL ENGil£ERING 14816 SE U6TH ST, RENTON, \,IA 980:59 4ll5-235-2707 ......,, .. .. ,.. E'JM B/12/02 ...... .,. .... B/12/02 E'JM }I~~l~:. EVENDELL PLAT Land Use/Cover Types PROJECT NO. FlGlJRE 3 Appendix A. Stonnshed Model lnpuUOutput Design Storm Rainfall Amounts Return Rainfall Period Amount (YRS) (IN) 2 2.00 JO 3.00 25 3.50 50 3.75 JOO 4.00 ' ., Appendix A.1. Subbasin Summary-East Basin Drainage Area: e-001 Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area CN Pervious 17. 8000 ac 85. 70 Impervious 1.9000 ac 98.00 Total 19. 7000 ac Pervious CN Data: Subbasin e-001 Perv . Impervious CN Data: Subbasin el Imperv Pervious TC Data: Flow type: Description: Sheet e I sheet Shallow e 1 shallow Channel e 1 channel Impervious TC Data: Flow type: Description: Fixed None Entered 85.70 98.00 Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 0.98 hrs 0.17 hrs 17.8000 ac 1.9000 ac Length: Slope: 300.00 ft 1. 70% 1484.00 ft 1.50% 950.00 ft 1.10% Length: Slope: 0.00 ft 0.00% Coeff: 0.1500 11.0000 17.0000 Travel Time 31.85min 18.36 min 8.88 min Coeff: Travel Time 10.0000 10.00 min Drainage Area: e-002 Hyd Method: SBUHHyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area Pervious 26.9000 ac Impervious 7.0000 ac Total 33.9000 ac Pervious CN Data: Subbasin e-002 Perv Impervious CN Data: Subbasin el Imperv Pervious TC Data: Flow type: Description: Sheet e2 sheet Shallow e2 shallow Channel e2 channel Impervious TC Data: Flow type: Description: Fixed None Entered CN 84.70 98.00 84.70 98.00 Loss Method: SCS.CN Number SCS Abs: 0.20 lntv: 1000 min TC 1.01 hrs 0.17 hrs 26.9000 ac 7.0000 ac Length: Slope: 300.00 fl 1.70% 922.00fl 1.60% 1824.00 fl 1.00% Length: Slope: 0.00 fl 0.00% Coeff: Travel Time 0.1500 31.85 min 11. 0000 I l. 04 min 17.0000 17.88 min Coeff: Travel Time 10.0000 10.00 min Drainage Area: e-003 Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: · 10.00 min Area CN TC Pervious 2.3000 ac 85.30 0.60 hrs Impervious 0.1000 ac 98.00 0.17 hrs Total 2.4000 ac Pervious CN Data: Subbasin e-003 Perv 85.30 2.3000 ac Impervious CN Data: Subbasin e3 lmperv 98.00 0.1000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Sheet e3 sheet 300.00 ft 1.70% 0. 1500 31.85 min Shallow e3 shallow 264.00 ft 1.10% 11.0000 3.81 min Channel e3 channel 106.00 ft 2.80% I 7.0000 0.62 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00 min. .·1 Drainage Area: e-004 Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: 10.00 min Area CN TC Pervious 0.9000ac 86.00 0.55 hrs Impervious 0.2000 ac 98.00 0.17hrs Total 1.1000 ac Pervious CN Data: Subbasin e-004 Perv 86.00 0.9000 ac Impervious CN Data: Subbasin e4 Imperv 98.00. 0.2000ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff Travel Time Sheet e4 sheet 300.00 ft 1.70% 0.1500 31.85min Channel e4 channel 200.00 ft 2.00% 17.0000 1.39 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00min Drainage Area: e-005 Hyd Method SBUH Hyd Peak Factor: 484.00 Stonn Dur: 24.00 hrs Area CN Pervious 18.1000 ac 84 .80 Impervious 5.4000 ac 98.00 Total 23.5000 ac Pervious CN Data: Subbasin e-005 Perv Impervious CN Data: Subbasin e5 Imperv Pervious TC Data: Flow type: Description: Sheet e5 sheet Shallow eS shallow Sheet e5 channel Impervious TC Data: Flow type: Description: Fixed None Entered 84.80 98.00 Loss Method: SCS CN Number SCS Abs: 0.20 · Intv: 10.00 min TC 1.81 hrs 0.17 hrs 18.1000 ac 5.4000 ac Length: Slope: 300.00 ft 2.70% 1248.00 fl 1.80% 705. 00 ft 1.40% Length: Slope: 0.00 ft . 0.00% Coeff: Travel Time 0.1500 26.47 min 11.0000 14.09 min 0.1500 68.19 min Coeff: Travel Time 10.0000 10.00 min Drainage Area: e-006 Hyd Method: SBUHHyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area CN Pervious 28.1000 ac 83.20 . Impervious 2.3000 ac 98.00 Total 30.4000 ac Pervious CN Data: Subbasin e-006 Perv 83.20 Impervious CN Data: Subbasin e5 Imperv 98.00 Pervious TC Data: Flow type: Description: Length: Sheet e6 sheet Shallow e6 shallow Impervious TC Data: Flow type: Description: Fixed None Entered Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 1.35 hrs 0.17 hrs 28.1000 ac 2.3000 ac Slope: Coeff: Travel Time 300.00 ft 1.00% I 777.00 ft 2.00% Length: Slope: 0.00 ft 0.00% 0.1500 39.38 min 5.0000 41.88 min Coeff: Travel Time 10.0000 10.00 min ., Drainage Area: e-007 Hyd Method: SBUH Hyd Peak Factor: 484. 00 Stonn Dur: 24.00 hrs Area Pervious 1 .8000 ac Impervious 0.0000 ac Total 1.8000 ac Pervious CN Data: Subbasin e-007 Perv Pervious TC Data: Flow type: Description: Sheet e7 sheet CN 81.00 98.00 81.00 Loss Method: SCS CN Number SCS Abs: lntv: TC 1.44 hrs 0.00 hrs 1.8000 ac 0.20 10.00min Length: Slope: 300.00 ft 1.00% Coeff: Travel Time 0.4000 86.31 min -, Drainage Area: ex_ east Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs lntv: 10.00min Area CN TC Pervious 11.1000 ac 81.80 2.10 hrs Impervious 0.5000 ac 98.00 0:17 hrs Total 11.6000 ac Pervious CN Data: Subbasin ex_ east Perv 81.80 11.IOOOac Impervious CN Data: Subbasin ex_east Imperv 98.00 0.5000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Sheet ex east sheet 300.00 ft 1.00% 0.4000 86.31 min Shallow ex east shallow 876.00 ft 1.50% 3.0000 39.74 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.000/o 10.0000 10.00 min Appendix A.2. Subbasin Summary-West Basin Drainage Area: w-001 Hyd Method: SBUHHyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area Pervious 2.3000ac Impervious 0.6000 ac Total 2.9000 ac Pervious CN Data: Subbasin wl Perv Impervious CN Data: Subbasin wl Pervious TC Data: Flow type: Description: Time Channel wl Impervious TC Data: Flow type: Description: Time Fixed wl Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min CN TC 86.00 0.26 hrs 98.00 0.17 hrs 86.00 2.3000 ac 98.00 0.6000 ac Length: Slope: Coeff: Travel 2610.00 ft 2.70% 17.0000 15.57 min Length: Slope: Coeff: Travel 0.00 ft 0.00%,. 10.0000 10.00 min ., Drainage Area: w-002 HydMethod: SBUHHyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area Pervious 14.5000 ac Impervious L8000ac Total 16.3000 ac Pervious CN Data: Subbasin w2 Perv Impervious CN Data: Subbasin w2 Imperv Pervious TC Data: Flow type: Description: Time Sheet None Entered Shallow None Entered Impervious TC Data: Flow type: Description: Time Fixed None Entered CN 86.00 98.00 86.00 98.00 Loss Method: SCS CN Number SCS Abs: 0.20 Jlitv: 10.00 min TC 0.57 hrs 0.17 hrs 14.5000 ac 1.8000 ac Length: Slope: Coeff: Travel 300.00 ft 1.70% 0.1500 31.85 min 585.00 ft 12.00% 11.0000 2.56 min Length: Slope: Coeff: Travel 0.00 ft 0.00%, 10.0000 10.00 min Drainage Area: w-003 - Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: 10.00 min Area CN TC Pervious 1.0000 ac 86,00 0.27 hrs Impervious 0.2000 ac 98.00 0.17 hrs Total l.2000 ac Pervious CN Data: Subbasin w3 Perv 86.00 1.0000 ac Impervious CN Data: Subbasin w3 Imperv 98.00 0.2000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Sheet w3 sheet 300.00 ft 10.70% 0.1500 15.26 min Channel w3 channel 272.00 ft 4.80% 17.0000 1.22 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00 min Drainage Area: w-004 HydMethod: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: J0.00 min Area CN TC Pervious 2.7000 ac 86.00 0.43 hrs Impervious 0.5000 ac 98.00 0.17hrs Total 3.2000 ac Pervious CN Data: Subbasin w4 Perv 86.00 2.7000 ac Impervious CN Data: Subbasin w4 98.00 0.5000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Sheet w4 sheet 300.00 ft 3.30% 0.1500 24.43 min Shallow w4 shallow 292.00 ft 7.50% 11.0000 1.62 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 J0.00 min , ., Drainage Area: w-005 Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: 10.00 min Area CN TC Pervious 1.8000 ac 86.00 0.29 hrs Impervious 0.4000 ac 98.00 0.17hrs Total 2.2000 ac Pervious CN Data: Subbasin w5 Perv 86.00 1.8000 ac Impervious CN Data: Subbasin w5 98.00 0.4000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Sheet w5 sheet 300.00 ft 10.00% 0.1500 15.68 min Shallow w5 shallow 322.00 ft 6.80% 11.0000 1.87 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00min , :I Drainage Area: w-006 . Hyd Method: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: 10:00 min Area CN TC Pervious 2.5000 ac 84.50 0.82 hrs Impervious 1.3000 ac 98.00 0.17hrs Total 3.8000 ac Pervious CN Data: Subbasin w6 Perv 84.50 2.5000 ac Impervious CN Data: Subbasin w6 98.00 1.3000 ac Pervious TC Data: Flow type: Description: Length: Slope: Coeff Travel Time Sheet w6 sheet 300.00 ft 0.70% 0.1500 45.42 min Shallow w6 shallow 613.00 ft 6.50% 11.0.000 3.64 min Impervious TC Data: · Flow type: Description: Length: Slope: Coeff Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00 min Drainage Area: w-007 HydMethod: SBUHHyd Loss Method: SCS CN Number Peak Factor: 484.00 SCS Abs: 0.20 Storm Dur: 24.00 hrs Intv: 10.00 min Area CN TC Pervious 5.4000 ac 84.50 0.53 hrs Impervious 2.4000 ac 98.00 0.17 hrs Total 7.8000 ac Pervious CN Data: Subbasin w7 Perv 84.50 5.4000 ac Impervious CN Data: Subbasin w7 98.00 2.4000 ac Pervious TC Data; Flow type: Description: Length: Slope: Coeff: Travel Time Sheet w7 sheet 300.00 ft 6.10% 0.2400 27.83 min Shallow w7 shallow 655.00 ft 6.10% 11.0000 4.02 min Impervious TC Data: Flow type: Description: Length: Slope: Coeff: Travel Time Fixed None Entered 0.00 ft 0.00% 10.0000 10.00 min ) ' Drainage Area: w-008 Hyd Meth.ad: SBUHHyd Peak Factor: 484.00 Stonn Dur: 24.00 hrs Area · Pervious 9.0000 ac Impervious 0.0000 ac Total 9.0000 ac Pervious CN Data: Subbasin w8 Perv Pervious TC Data: Flow type: Description: Time Sheet w8 sheet Shallow w8 shallow Impervious TC Data: Flow type: Description: Time Fixed None Entered CN 83.40 0.00 83.40 Loss Method: SCS CN Number SCS Abs: Intv: 0.20 10.00 min TC 0.79 hrs 0.17 hrs 9.0000ac Length: Slope: 300.00ft 6.70% ]020.00ft 6.90% Length: Slope: 0.00 ft 0.00% Coeff: Travel 0.4000 40.33 min 9.0000 7.19 min Coeff:: Travel 10.0000 10.00 min ., Drainage Area: ex_west Hyd Method: SBUH Hyd Peak Factor: 484.00 Stonn Dur: 24.00 hrs Area Pervious I. 8000 ac Impervious O. l 000 ac Total 1.9000 ac Pervious CN Data: Subbasin ex_ west Perv Impervious CN Data: Subbasin ex west Imperv Pervious TC Data: Flow type: Description: Time Sheet ex west sheet Impervious TC Data: Flow type: Description: Time Fixed wl CN 84.00 98.00 84.00 98.00 Loss Method: SCS CN Number SCS Abs: lntv: 0.20 10.00 min TC 0.38 hrs 0.17 hrs 1.8000 ac 0.1000 ac Length: Slope: 210.00 ft 4.80% Length: Slope: Coeff: 0.2400 Coeff: Travel 23.02 min Travel 0.00 ft 0.00% 10.0000 10.00 min Table B.1. Hydrograph Routing -East Basin -2-Year Storm ROUTEHYD O THRU [Existing East] USING TYPE1A AND [2 yr] NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin / Hyd ac cfs cfs ratio fl fl/s fl/s ------------ D-Dum2 19.7 2.1303 122.33 0.02 0.3312 X-Sect 3.0688 ---e-001 D-Dum1 53.6 6.625 122.33 0.05 0.5728 X-Sect 4.4532 ---e-002 D-145 53.6 6.5953 121.12 0.05 0.5744 X-Sect 4.4169 - D-144 53.6 6.5642 117.92 0.06 0.6659 X-Sect 4.3432 -- D-143 53.6 6.5478 122.41 0.05 0.6381 X-Sect 4.0213 -- D-142 53.6 6.5467 82.3869 0.08 0.6881 X-Sect 3.5759- D-141 53.6 6.5465 10.3949 0.63 1.6141 X-Sect 1.1146 -- P-117 65.2 7.0246 6.5804 1.07 0.9037 12" Diam 9.4073 8.3784 ex_east D-140 65.2 7.0224 124.5 0.06 0 .4 782 X-Sect 3.1305 ---- D-139 65.2 7.018 117.81 0.06 0.4685 X-Sect 3.4675- D-138 65.2 7.013 94.8108 0.07 0.6314 X-Sect .3.4413 --- D-137 67.6 7.2807 279 0.03 0.4113 X-Sect 5.3323 --e-003 P-116 67.6 7.2787 7.2535 1 1.2342 18" Diam 4.6787 4.1046 D-136 67.6 7.2745 61.7242 0.12 0.6832 X-Sect 3.5858 -- D-135 67.6 7.2645 66.6905 0.11 0.7836 X-Sect 2.9393 -- D-134 67.6 7.2596 70.9939 0.1 0.5719 X-Sect 3.6244 ---- D-133A 67.6 7.2557 93.7984 0.08 0.6719 X-Sect 3.6325 ---- D-133 67.6 7.2549 26.6671 0.27 1.4156 X-Sect 1.1841 -- P-115 68.7 7.4254 6.9473 1.07 0.9067 12" Diam 9.9203 8.8456 e-004 D-132 68.7 7.4237 226.87 0.03 0.5902 X-Sect 5.7063- P-114 92.2 10.2247 18.9199 0.54 1.0474 24" Diam 6.1392 6.0224 e-005 D-131 92.2 10.2216 338.51 0.03 0.5631 X-Sect 4.9185 - D-130 92.2 10.2183 33.2703 0.31 0.8395 X-Sect 4.3224- D-129 92.2 10.2164 8.6723 1.18 -1 X-Sect 1.178 --- P-113 92.2 10.212 23.5738 0.43 0.6902 18" Diam 12.8615 13.34 D-128 92.2 10.2081 266.41 0.04 0.6392 X-Sect 4.3565 -- D-127 92.2 10.1973 1354.11 0.01 0.6263 X-Sect 2.0863 ---- D-126 92.2 10.1853 491.48 0.02 0.3323 X-Sect 1.4977 -'-- D-125 92.2 10.132 3470.27 0 0.3539 X-Sect 0.8642 -- D-124 92.2 9.9841 549.84 0.02 0.2991 X-Sect 0.5983- D-123 92.2 9.9643 3827.85 0 0.4105 X-Sect 1.946- P-112 92.2 9.9216 4.3371 2.29 -1 12" Diam 2.2876 5.5221 D-122 92.2 9.9128 50.2681 0.2 0.904 X-Sect 2.771 ---- D-121 122.6 12.0698 594.02 0.02 0.2893 X-Sect 10.2968 --e-006 P-111 122.6 12.0648 15.3148 0.79 1.0036 18" Diam 9.6013 8.6664 D-120 122.6 12.0245 18.2879 0.66 1.4658 X-Sect 2.1936 ---- D-119 .122.6 12.0107 17.5281 0.69 0.6067 X-Sect 4.6997 -- D-118 122.6. 12.0027 179.94 0.07 0.4436 X-Sect 5.2531 - D-117 122.6 11".9926 61.1492 0.2 · 1.0638 X-Sect 2.9017 - D-116 122.6 11.9823 27.9865 0.43 1.096 X-Sect 4.2499- D-115 122.6 11.9814 78.2241 0.15 1.2007 X-Sect 4.2155 - P-110 122.6 11.972 30.6525 0.39 0.868 24" Diam 9.156 9.757 D-114 122.6 11.9572 47.75 0.25 1.1715 X-Sect 4.2164 -- D-113 124.4 12.0112 319.76 0.04 0.6751 X-Sect 5.8978 -----e-007 D-112 124.4 12.0055 1134.16 0.01 0.5548 X-Sect 5.7484 -- D-111 124.4 11.9853 413.21 0.03 0. 7639 X-Sect 3.7479 -- .·1 D-110 124.4 11.9689 241.55 0.05 0.698 X-Sect 3.9096 ----- Reh App Bend Junct HW Max El/ Loss Head Loss Loss Elev Rim El Fr Node To Node fl fl fl ft ft ft N-110 408.288 N-111 N-110 409.238 -na----na----na--409.238 411.92 N-112 N-111 409.9703 --na---na----na--409.9703 414.13 N-113 N-112 411.6608 --na----na----na--411.6607 415.64 N-114 N-113 412.5349 -na--na----na--412.5349 415.67 N-115 N-114 414.1314 -na----na---na--414.18 414.08 N-116 N-115 415.5033 -na--na---na-415.5033 416.5 N-117 N-116 415.5562 -na--na--na--415.5562 416.39 N-118 N-117 416.3861 -na---na---na-416.3861 416.39 N-119 N-118 416.626 --na--na---na--416.71 416.61 N-120 N-119 418.44 --na---na----na--418.24 418.14 N-121 N-120 420.9399 --na----na----na-420.43 420.33 N-122 N-121 421.5157 -na--na---na-421.5157 422.69 N-123 N-122 422.9861 -na--na---na-422.9861 423.31 N-124 N-123 425.626 -na--na---na--423.41 423.31 N-125 N-124 423.64 --na---na---na--423.64 424.05 · N-126 N-125 433.8967 --na---na----na--424.9 424.8 N-127 N-126 425.6399 --na---na----na--425.6399 426.02 N-128 N-127 426.0798 --na--na---na--426.0798 426.52 NC129 N-128 427 .6098 --na--na----na-427.6097 428.27 N-130 N-129 429.6497 -na--na--na-429.4 429.3 N-131 N-130 430.9699 -na---na---na-430.83 430.73 N-132 N-131 432.4499 --na---na---na-432.45 432.79 N-133 N-132 437.2623 --na----na----na--436.5 436.4 N-134 N-133 436.5119 --na---na----na--436.03 435.93 N-135 N-134 437.4999 -na---na---na--437.57 437.47 N-136 N-135 440.3899 --na----na---na--440.25 440.15 N-137 N-136 441.418 -na--na----na-441.418 442.1 N-137A N-137 442.088 --na---na---na--441.99 441.89 N-138 N-137A 445.5185 --na--na----na-442.9 442.8 N-139 N-138 442.9019 -na---na---na-442.9 442.8 N-140 N-139 443.8899 --na---na---na--443.14 443.04 N-141 N-140 444.3999 -na-. --na---na-444.3999 444.84 N-142 N-141 445.6699 -na--na--na--445.6699 446.11 N-143 N-142 446.8898 -na--na---na-446.8898 447.71 N-144 N-143 448.3436 --na---na---na--448.2 448.1 N-145 N-144 448.4599 --na---na--na-" · 447.84 447.74 N-146 N-145 449.6399 --na---na--na--449.6399 449.84 N-147 N-146 452.3699 --na---na--na-452.3698 452.71 N-148 N-147 453.5398 -na--na--na-453.5398 453.89 N-149 N-148 456.7368 -na--na--na-454.3 454.2 N-150 N-149 454.303 -na--na--na-454.3029 454.65 N-151 N-150 456.4129 --na--na--na-455.87 455.77 N-152 N-151 460.5699 -na---na--na-460.56 460.46 N-153 N-152 463.89 -na--na---na--463.89 464.17 N-154 N-153 467.8199 --na----na---na-467.44 467.34 .·! Table B.2. Hydrograph Routing-East Basin -10-Year Storm ROUTEHYD [] THRU [Existing East] USING TYPE1A AND [10 yr] NOTZERO ACTUAL Reach Area Flow Full a % Full nDepth Size nVel Nel CBasin /Hyd ac cfs cfs ratio ft ft/s ft/s ---------- D-Dum2 19.7 4.4884 122.33 0.04 0.4719 X-Sect 3.935 ----e-001 D-Dum1 53.6 13.1058 122.33 0.11 0.81 X-Sect 5.5304 ---e-002 D-145 53.6 13.1051 121.12 0.11 0.8142 X-Sect 5.4927 - D-144 53.6 13.1036 117.92 0.11 0.9649 X-Sect 5.2679 ----- D-143 53.6 13.1 122.41 0.11 0. 9032 X-Sect 4.856 ---- D-142 53.6 13.0953 82.3869 0.16 0.9821 X-Sect 4.3102 -- D-141 53.6 13.0948 10.3949 1.26 -1 X-Secl 1.2597 --- P-117 65.2 14.3238 . 6.5804 2.18 -1 12" Diam 2.1767 8.3784 ex_ east 0-140 65.2 14.3181 124.5 0.12 0.6926 X-Sect 3.9913 --- 0-139 65.2 14.3076 117.81 0:12 0.6891 X-Sect 4.3262- 0-138 65.2 14.2973 94.8108 0.15 0.9065 X-Sect 4.2086 --- 0-137 67.6 14.8971 279 0.05 0.5622 X-Sect 6.5644-e-003 P-116 67.6 14.8875 7.2535 2.05 -1 18" Diam 2.0525 4.1046 0-136 67.6 14.8791 61.7242 0.24 0.9641 X-Sect 4.5155 -- 0-135 67.6 14.86 66.6905 0.22 1 .1209 X-Sect 3.6062 ---- D-134 67.6 14.8509 70.9939 0.21 0.8189 X-Sect 4.472-- D-133A 67.6 14.8437 93.7984 0.16 0.899 X-Sect 4.4767 --· 0-133 67.6 14.8424 26.6671 0.56 1.9795 X-Sect 1.4503 -- P-115 68.7 15.1643 6.9473 2.18 -1 12" Diam 2.1828 8.8456 e-004 0-132 68.7 15.1617 226.87 0.07 0.8315 X-Secl 7.0313 -- P-114 92.2 20.3817 18.9199 1.08 -1 24" Diam 1.0773 6. 0224 e-005 0-131 92.2 20.3728 338.51 0.06 0.8183 X-Secl 6.0985 - D-130 92.2 20.3642 33.2703 0.61 1.2093 X-Secl 5.2653 -- D-129 92.2 20.3511 8.6723 2.35 -1 X-Sect 2.3467 --- P-113 92.2 20.3415 23.5738 0.86 1.0749 18" Diam 15.0091 13.34 D-128 92.2 20.3328 266.41 0.08 0.9398 X-Sect 5.4109 ·- D-127 92.2 20.3088 1354.11 0.01 0. 7502 X-Sect 2.4283 --- 0-126 92.2 20.2866 491.48 0.04 0.428 X-Sect 1.9106 ---- D-125 92.2 20.1873 3470.27 0.01 0.4582 X-Sect 1.0267 ··--- D-124 92.2 20.03 549.84 0.04 0.4223 X-Sect 0.7679- D-123 92.2 19.9985 3827.85 0.01 0.5331 X-Sect 2.3162- P-112 92.2 19.9587 4.3371 4.6 -1 12" Diam 4.6019 5.5221 D-122 92.2 19.9456 50.2681 0.4 1.2487 X-Sect 3.3192 ··- 0-121 122.6 24.93 594.02 0.04 0.4161 X-Sect 13.223-e-006 P-111 122.6 24.8832 15.3148 1.62 -1 18" Diam 1.6248 8.6664 D-120 122.6 24.6416 18.2879 1.35 -1 X-Sect 1.3474- 0-119 122.6 24.5438 17.5281 1.4 -1 X-Sect 1.4002 - 0-118 122.6 24.5308 179.94 0.14 0.6339 X-Sect 6.562- D-117 122.6 24.5144 61.1492 0.4 1.4223 X-Sect 3.6544- 0-116 122.6 24.4971 27.9865 0.88 1.4271 X-Sect 5.1474 - 0-115 122.6 24.4955 78.2241 0.31 1.6574 X-Sect 5.1522 - P-110 122.6 24.4801 30.6525 0.8 1.3515 24" Diam 10.8367 9.757 D-114 122.6 24.4557 47.75 0.51 1.5399 X-Sect 5.2816 - 0-113 124.4 24.6393 319.76 0.08 1.0057 X-Secl 7.2971 --e-007 D-112 124.4 24.6301 1134.16 0.02 0. 7 42 X-Sect 7.4221 - D-111 124.4 24.5979 413.21 0.06 1 .1252 X-Sect 4.6448 -- D-110 124.4 24.5719 241.55 0.1 1. 0455 X-Sect 4.8977 ----- Reh App Bend Junct HW Max Ell Loss Head Loss Loss Elev Rim El .. Fr Node To Node fl fl fl fl fl fl N-110 408.6355 N-111 N-110 409.5854 -na---na--na-409.5854 411.92 N-112 N-111 410.6952 --na----na---na--410.6952 414.13 N-113 N-112 412.3751 --na--na----na-412.3751 415.64 N-114 N-113 412.985 -na---na--na-412.985 415.67 N-115 N-114 414.5504 -na--na--na-414.18 414.08 N-116 N-115 417.346 -na--na--na-416.6 416.5 N-117 N-116 416.6529 -na--na--na-416.49 416.39 N-118 N-117 417.3199 -na--na---na-416.49 416.39 N-119 N-118 416.7623 --na-. 0-na----na-416.71 416.61 N-120 N-119 418.4399 -na---na---na-418.24 418.14 N-121 N-120 420.9399 -na----na---na-420.43 420.33 N-122 N-121 421.3322 -na----na--na-421.3322 422.69 N-123 N-122 427.5867 -na---na--na-423.41 423.31 N-124 N-123 426.0499 -na---na----na--423.41 423.31 N-125 N-124 423.6399 -na---na----na-423.64 424.05 N-126 N-125 465.1461 -na--na---na-424.9 424.8 N-127 N-126 425.6399 -na--na---na-425.6399 426.02 N-128 N-127 426.0798 -na--na--na-426.0798 426.52 N-129 N-128 427.6098 -na--na--na-427.6097 428.27 N-130 N-129 429.6497 -na--na---na-429.4 429.3 N-131 N-130 430.9699 -na--na--na-430.83 430.73 N-132 N-131 432.4499 -na--na--na-432.45 432.79 N-133 N-132 441.2068 -na---na--na--436.5 436.4 N-134 N-133 436.5119 -na--na---na-436.03 435.93 N-135 N-134 437.4999 -na--na---na-437.57 437.47 N-136 N-135 440.3699 -na---na----na-440.25 440.15 N-137 N-136 442.9103 -na---na---na-442.2 442.1 N-137A N-137 442 .67 --na---na---na--441.99 441.69 N-136 N-137A 458.8656 -na--na--na-442.9 442.6 N-139 N-138 443.1294 -na--na-. -na-442.9 442.8 N-140 N-139 443.69 --na---na---na--443.14 443.04 N-141 N-140 444.3999 -na--na----na-444.3999 444.84 N-142 N-141 445.7908 -na--na--na-445.7908 446.11 N-143 N-142 447.0106 -na--na---na-447.0107 447.71 N-144 N-143 451 .3791 -na---na--na-448.2 446.1 N-145 N-144 448.46 -na---na---na-447.84 447.74 N-146 N-145 449.6399 -na--na---na--449.6399 449.84 N-147 N-146· 452.3698 -na--na--na-452.3698 452.71 N-148 N-147 453.5397 -na--na--na-453.5397 453.89 N-149 . N-148 464.129 -na--na--na-454.3 454.2 N-150 N-149 454.3029 -na-. -na--na-454.3029 454.65 N-151 N-150 456.4128 --na---na---na-455.87 455.77 N-152 N-151 460.5699 -na~ -na---na-460.56 460.46 'J-153 N-152 . 463.6899 -na----na--na-463.89 464.17 4-154 N-153 467.8199 -na--na----na-467.44 467.34 :·{ Table B.3. Hydrograph Routing -East Basin -25-Year Stonn ROUTEHYD O THRU (Existing East] USING TYPE1A ANO [25 yr] NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin 1 ac cfs cfs. ratio ft ft/s ft/s .. ~ __ .. ___ D-Dum2 19.7 5.7736 122.33 0.05 0.5347 X-Sect 4.2649 ---e-001 D-Oum1 53.6 16.6641 122.33 0.14 0 .9204 X-Sect 5.9522--e-002 0-145 53.6 16.6623 121.12 0.14 0.9253 X-Sect 5.911 --- D-144 53.6 16.6597 117.92 0.14 1. 095 X-Sect 5.6189 -- D-143 53.6 16.6543 122.41 0.14 1.0158 X-Sect 5.1748 --- D-142 53.6 16.6481 82.3869 0.2 1.1029 X-Sect 4.6242-- 0-141 53.6 16.6444 10.3949 1.6 -1 X-Sect 1.6012-- P-117 65.2 18.3188 6.5804 2.78 -1 12" Diam 2.7838 8.3784 ex_east 0-140 65.2 18.3118 124.5 0.15 0. 7894 X-Sect 4.3271 ·- D-139 65.2 18.2992 117.81 0.16 0.786 X-Sect 4.6556-- 0-138 65.2 18.2868 94.8108 0.19 1.0247 X-Sect 4.5015 - 0-137 67.6 19.0686 279 0.07 0.6269 X-Sect 7.0354 ·-· e-003 P-116 67.6 · 19.0592 7.2535 2.63 -1 18" Diam 2.6276 4.1046 D-136 67.6 19.0493 61.7242 0.31 1.0913 X-Sect 4.8719 -- D-135 67.6 19.0273 66.6905 0.29 1.2672 X-Sect 3.86 ··-- D-134 67.6 19.0167 70.9939 0.27 0.926 X-Sect 4.7959 --- D-133A 67.6 19.0082 93.7984 0.2 0.9908 X-Sect 4.8691 --- D-133 67.6 19.0069 26.6671 0.71 2.2289 X-Sect 1.5584- P-115 68.7 19.4194 6.9473 2.8 -1 12· Diam 2.7952 8.8456 e-004 0-132 68.7 19.4163 226.87 0.09 0.9372 X-Sect 7.5367-- P-114 92.2 25.943 18.9199 1.37 -1 24" Diam 1.3712 6.0224 e-005 0-131 92.2 25.9323 338.51 0.08 0.9321 X-Sect 6.5545- 0-130 92.2 25.9219 33.2703 0.78 1.3721 X-Sect 5.6512 --- D-129 92.2 25.9106 8.6723 2.99 -1 X-Sect 2.9877-- P-113 92.2 25.8992 23.5738 1.1 -1 18" Diam 1.0986 13.34 D-128 92.2 25.8888 266.41 0.1 1.076 X-Sect 5.818 -· D-127 92.2 25.8608 1354.11 0.02 0.8003 X-Sect 2.5676- 0-126 92.2 25.8358 491.48 0.05 0.4713 X-Sect 2.076 -··- D-125 92.2 25.7224 3470.27 0.01 0.5018 X-Sect 1.0908 - 0-124 92.2 25.5489 549.84 0.05 0.478 X-Sect 0.836- D-123 92.2 25.5134 3827.85 0.01 0.584 X-Sect 2.4616- P-112 92.2 25.4763 4.3371 5.87 -1 12· Diam 5.8741 5.5221 0-122 92.2 25.4617 50.2681 0.51 1.3879 X-Sect 3.5601 -- D-121 122.6 32.0486 594.02 0.05 0.4735 X-Sect 14.376-e-006 P-111 122.6 32.0049 15.3148 2.09 -1 18" Diam 2.0898 8.6664 D-120 122.6 31.7866 18.2879 1.74 -1 X-Sect 1.7381- 0-119 122.6 31.6961 17.5281 1.81 -1 X-Sect 1.8083 - D-118 122.6 31.6812 179.94 0.18 0. 7203 X-Sect 7.0837- D-117 122.6 31.6627 61.1492 0.52 1 ,5908 X-Sect 3.9591 -- D-116 122.6 31.6418 27.9865 1.13 -1 X-Sect 1.1306- D-115 122.6 31.64 78.2241 0.4 1 . 866 X-Sect 5.5186- P-110 122.6 31.6228 30.6525 1.03 1.7027 24" Diam 11.096 9.757 D-114 122.6 31.5955 47.75 0.66 1.7176 X-Sect 5.6991 - D-113 124.4 31.8576 319.76 0.1 1 .1584 X-Sect 7.8462-e-007 0-112 124.4 31.8471 1134.16 0.03 0.8307 X-Sect 8.1092- D-111 124.4 31.8116 413.21 0.08 1.2906 X-Sect 4.9987- D--110 124.4 31.7828 241.55 0.13 1 .207 X-Sect 5.2894- Reh App Bend · Junct HW Max El/ Loss Head Loss Loss Elev Rim El Fr Node To Node fl fl fl fl fl fl N-110 408.797 N-111 N-110 409.747 --na----na----na-409.747 411.92 N-112 N-111 410.8606 -na----na---na-410.8606 414.13 N-113 N-112 412. 5405 --na----na----na--412.5405 415.64 N-114 N-113 413.1504 --na---na--na-413.1505 415.67 N-115 N-114 414.8065 -na---na---na-414.18 414.08 N-116 N-115 418.962 -na----na--na-416.6 416.5 N-117 N-116 416.6529 -na----na--na-416.49 416.39 N-118 N-117 417.3199 -na--na--na-416.49 416.39 N-119 N-118 416.9307 -na---na--na-416.71 416.61 N-120 N-119 418.4399 -na---na--na-418.24 418.14 N-121 N-120 420. 9399 --na----na---na-420.43 420.33 N-122 N-121 421.5229 --na----na----na-421.5229 422.69 N-123 N-122 431.8698 -na----na--na-423.41 423.31 N-124 N-123 426.0499 -na--na--na-423.41 423.31 N-125 N-124 423.64 --na----na---na-423.64 424.05 N-126 N-125 491.2671 --na----na--na--424.9 424.8 N-127 N-126 425.6399 -na--na--na-425.6399 426.02 N-128 N-127 426.0798 -na--na--na-426.0798 426.52 N-129 N-128 427.6098 -na--na--na-427.6097 428.27 N-130 N-129 429.6497 -na--na--na-429.4 429.3 N-131 N-130 430.9699 --na---na--na-430.83 430.73 N-132 N-131 432.45 -na--na---na-432.45 432.79 N-133 N-132 437 .2202 --na--na---na-436.5 436.4 N-134 N-133 436.5119 -na---na---na-436.03 435.93 N-135 N-134 437 .85 --na---na---na-437.57 437.47 N-136 N-135 440.39 --na--na---na-440.25 440.15 N-137 N-136 444.033 --na--na---na-442.2 442.1 N-137A N-137 442.8699 -na--na---na-441.99 441.89 N-138 N-137A 469.665 --na---na---na-442.9 442.8 N-139 N-138 443.3789 -na--na--na-442.9 442.8 N-140 N-139 443.89 --na--na---na-443.14 443.04 N-141 N-140 444.3999 -na--na--na-444.3999 444;84 N-142 N-141 445.9371 -na---na--na-445.9371 446.11 N-143 N-142 447.157 -na---na--na-447.157 447.71 N-144 N-143 453.928 -na----na---na-448.2 448.1 N-145 N-144 448.46 -na--na--na-447.84 447.74 N-146 N-145 449.6399 -na---na---na-449.6399 449.84 N-147 N-146 452.3699 -na---na--na-452.3699 452.71 N-148 N-147 453.5398 -na---na--na-453.5398 453.89 N-149 N-148 470.8597 -na---na--na-454.3 454.2 N-150 N-149 454.3029 -na---na--na-454.3029 454.65 N-151 N-150 456.4129 -na---na---na--455.87 455.77 N-152 N-151 460.5699 -na.:. -na---na--460.56 460.46 1-153 N-152 463.8981 -na---na--na-463.8981 464.17 N-154 N-153 467.828 -na--na--na-467.44 467.34 , ., Table 8.4. Hydrograph Routing -East Basin -SO-Year Stonn ROUTEHYD O THRU [Existing East] USING TYPE1A AND [50 yr] NOTZERO-ACTUAL Reach Area Flow Full Q % Full. nDepth Size nVel Nel CBasin I Hyd ac cfs cfs ratio ft ft/s ftls ----------- D-Dum2 19.7 6.4328 122.33 0.05 0.5644 X-Sect 4.4125 ----e-001 D-Dum1 53.6 18.4875 122.33 0.15 0.9737 X-Sect 6.1401 -----e-002 D-145 53.6 18.4851 121.12 0.15 0. 9789 X-Sect 6.0973- D-144 53.6 18.482 117.92 0,16 1.1561 X-Sect 5.7757 -- D-143 53.6 18.4757 122.41 0.15 1.0682 X-Sect 5.3178 ---- D-142 53.6 18.4689 82.3869 0.22 1.16 X-Sect 4.7688 -- D-141 53.6 18.4652 10.3949 1.78 -1 X-Sect 1.7764- P-117 65.2 20.3744 6.5804 3.1 -1 12" Diam 3.0962 8.3784 ex_east D-140 65.2 20.3667 124.5 0.16 0.8355 X-Sect 4.4786- D-139 65.2 20.3531 117.81 0.17 0.8317 X-Sect 4.8035- D-138 65.2 20.3398 94.8108 0.21 1.0799 X-Sect 4.6329 ---- D-137 67.6 21.2149 279 0.08 0.6572 X-Sect 7.2468 -e-003 P-116 67.6 21.2056 7.2535 2.92 -1 18" Diam 2.9235 4.1046 D-136 67.6 21.1949 61.7242 0.34 1 . 152 X-Sect 5.0314 -- D-135 67.6 21.1716 66.6905 0.32 1.3357 X-Sect 3.9737 -- D-134 67.6 21.1602 70.9939 0.3 0.9762 X-Sect 4.9411 ---- D-133A 67.6 21.1511 93.7984 0.23 1.035 X-Sect 5.0466- D-133 67.6 21.1496 26.6671 0.79 2. 3487 X-Sect 1.6064 -- P-115 68.7 21.6082 6.9473 3.11 -1 12" Diam 3.1103 8.8456 e-004 D-132 68.7 21.605 226.87 0.1 0.9869 X-Sect 7.7628- P-114 92.2 28.7909 18.9199 1.52 -1 24" Diam 1.5217 6.0224 e-005 D-131 92.2 28.7784 338.51 0.09 0.9857 X-Sect 6.7585- D-130 92.2 28.7663 33.2703 0.86 1 .4508 X-Sect 5.8219 - D-129 92.2 28.7555 8.6723 3.32 -1 X-Sect 3.3158 --- P-113 92.2 28.7428 23.5738 1.22 -1 18" Diam 1.2193 13.34 D-128 92.2 28.731 266.41 0.11 1. 1405 X-Sect 5.9997- D-127 92.2 28.699 1354.11 0.02 0.8231 X-Sect 2.6309 -- D-126 92.2 28.6712 491.48 0.06 0.4918 X-Sect 2.1506 -- D-125 92.2 28.5445 3470.27 0.01 0.5218 X-Sect 1.1196 -- D-124 92.2 28.3566 549.84 0.05 0.5043 X-Sect 0.8666 ----- D-123 92.2 28.3183 3827.85 0.01 0.6073 X-Sect 2.5267- P-112 92.2 28.2813 4.3371 6.52 -1 12" Diam 6.5208 5.5221 D-122 92.2 28.2656 50.2681 0.56 1.4497 X-Sect 3.6834- D-121 122.6 35.6853 594.02 0.06 0.5006 X-Sect 14.8923 ---e-006 P-111 122.6 35.6419 15.3148 2.33 -1 18" Diam 2.3273 8.6664 D-120 122.6 35.4329 18.2879 1.94 -1 X-Sect 1.9375- D-119 122.6 35.3437 17.5281 2.02 -1 X-Sect 2.0164 - D-118 122.6 35.3278 179.94 0.2 0. 7605 X-Sect 7.315 -- D-117 122.6 35.308 61.1492 0.58 1.6707 X-Sect 4.0938- D-116 122.6 35.2852 27.9865 1.26 -1 X-Sect 1.2608 - D-115 122.6 35.2833 78.2241 0.45 1.9632 X-Sect 5.68- P-110 122.6 35.2651 30.6525 1.15 -1 24" Diam 1.1505 9.757 D-114 122.6 35.2359 47.75 0.74 1.8022 X-Sect 5.8823- D-113 124.4 35.5397 319.76 0.11 1.2299 X-Sect 8.0881 ----e-007 )-112 124.4 35.5284 1134.16 0.03 0.8726 X-Sect 8.4163 - D-111 124.4 35.4908 413.21 0.09 1.3677 X-Sect 5.1548 -- D-110 124.4 35.4602 241.55 0.15 1.2828 X-Sect 5.4622 --- Reh App Bend Junct HW Max El/ Loss Head Loss Loss Elev Rim El ... Fr Node To Node ft ft ft ft ft ft N-110 · 408.8728 N-111 N-110 409.8228 --na----na---na--409.8228 411.92 N-112 N-111 410.9377 -na----na---na--410.9377 414.13 N-113 N-112 412.6176 -na---na---na--412.6176 415.64 N-114 N-113 413.2275 -na----na---na-413:2275 415.67 N-115 N-114 414.9305 --na--na---na-414.18 414.08 N-116 N-115 415.8377 -na--na--na-415.8377 416.5 N-117 N-116 416.2331 --na---na--na-416.2331 416.39 N-118 N-117 417.0631 -na--na---na-416.49 416.39 N-119 N-118 417.0166 -na--na---na-416.71 416.61 N-120 N-119 418.4399 --na----na----na-418.24 418.14 N-121 N-120 420.9399 --na----na---na-420.43 420.33 N-122 N-121 421.6109 -na---na--na-421.6109 422.69 N-123 N-122 434.4431 -na---na---na--423.41 423.31 N-124 N-123 426.0499 -na---na--na-423.41 423.31 N-125 N-124 423.6399 -na---na----na-423.6399 424.05 N-126 N-125 506.9789 -na--na---na-424.9 424.8 N-127 N-126 425.6399 -na--na--na-425.6399 426.02 N-128 N-127 426.0798 -na--na---na-426.0798 426.52 N-129 N-128 427.6098 -na--na---na-427.6097 428.27 N-130 N-129 429.6497 --na--na--na-429.4 429.3 N-131 N-130 · 430.9699 -na--na---na-430.83 430.73 N-132 N-131 432.5004 -na--na--na-432.5004 432.79 N-133 N-132 438.2302 -na---na----na-436.5 436.4 N-134 N-133 436.5119 -na--na--na-436.03 435.93 N-135 N-134 437.85 -na----na--na-437.57 437.47 N-136 N-135 440.3899 --na---na---na-440.25 440.15 N-137 N-136 444.7122 --na--na--na-442.2 442.1 N-137A N-137 442.8699 -na----na---na-441.99 441.89 N-138 N-137A 476.2553 -na---na--na-442.9 442.8 N-139 N-138 443.4986 -na--na--na-442.9 442.8 N-140 N-139 443.8899 --na----na--na-443.14 443.04 N-141 N-140 444.3999 --na---na--na-444.3999 444.84 N-142 N-141 446.0057 -na---na--na-446.0057 446.11 N-143 N-142 447.2256 --na----na--na-447.2256 447.71 N-144 N-143 455.4835 -na--na--na-448.2 448.1 N-145 N-144 448.46 -na--na--na-447.84 447.74 N-146 N-145 449.6399 -na--na--na-449.6399 449.84 N-147 N-146 452 .3699 --na--na--na-452.3698 452.71 N-148 N-147 453.5398 -na--na--na-453.5398 453.89 N-149 N-148 474.9647 -na--na--na-454.3 454.2 N-150 N-149 454.3029 -na--na--na-454.3029 454.65 N-151 N-150 456.4129 -na--na--na-455.87 455.77 N-152 N-151 460.5836 -na;_ -na--na-460.56 460.46 1-153 N-152 463.9726 -na---na---na-463.9726 464.17 .~-154 N-153 467.9025 -na--na--na-467.44 467.34 Table B.5. Hydrograph Routing -East Basin -100-Year Stonn ROUTEHYD O THRU [Existing East] USING TYPE1A AND [100 yr] NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin l Hyd O-Dum2 O-Dum1 0-145 0-144 0-143 0-142 0-141 P-117 0-140 0-139 D-138 D-137 P-116 0-136 0-135 0-134 0-133A 0-133 P-115 0-132 P-114 0-131 0-130 0-129 P-113 0-128 D-127 D-126 D-125 0-124 D-123 P-112 D-122 0-121 P-111 D-120 0-119 0-118 0-117 D-116 0-115 P-110 0-114 0-113 '1-112 -111 ac cts ratio ft fl/s tus 19.7 7.1007 0.06 0.5932 X-Sect 4.5504 ---- 53.6 20,334 0.17 1.0256 X-Sect 6.3154 --·-- 53.6 20.3311 121.12 0.17 1.0311 X-Sect 6.2711 -- 53.6 20.3274 117.92 0.17 1.2148 X-Sect 5.9225 ----- 53.6 20.3204 122.41 0.17 1.1183 X-Sect 5.4519 ---- 53.6 20.3129 82.3869 0.25 1.2157 X-Sect 4.9037 - 53.6 20.3094 1.95 -1 X-Sect 1.9538 -- e-001 e-002 65.2 22.46 • 3.41 -1 12· Diam 3.4132 8.3784 ex east 65.2 22.4518. 0.18 0.8802 X-Sect 4.6208 -- 65.2 22.4372 117.81 0.19 0.8757 X-Sect 4.9419 ---- 65.2 22.4229 0.24 1.1329 X-Sect 4.756 --- 67.6 23.3927 0.08 0.6862 X-Sect 7.4448 --e-003 67.6 23.3835 3.22 -1 18" Diam 3.2238 4.1046 67.6 23.3721 61.7242 0.38 1.2109X-Sect 5.1805---- 67.6 23.3475 66.6905 0.35 1.4016 X-Sect 4.08 - 67.6 23.3353 70.9939 0.33 1.0244 X-Sect 5.0771 ---- 67.6 23.3254 93.7984 0.25 1.0782 X-Sect 5.2133 -- 67.6 23.3239 26.6671 0.87 2.4653 X-Sect 1.6511 -- 68. 7 23.829 6.9473 3.43 -1 12" Diam 3.43 8.8456 e-004 68.7 23.8256 226.87 0.11 1.0347 X-Sect 7.9743 - 92.2 31.6894 18.9199 1.67 -1 24" Diam 1.6749 6.0224 e-005 92.2 31.6761 338.51 0.09 1.0378 X-Sect 6.9502 --- 92.2 31.6628 33.2703 0.95 1.5281 X-Sect 5.9813 -- 92.2 31.6529 8.6723 3.65 -1 X-Sect 3.6499 ---- 92.2 31.6395 23.5738 1.34 -1 18" Diam 1.3421 13.34 92.2 31.627 266.41 0.12 1.2034 X-Sect 6.1704 ---- 92.2 31.5932 1354.11 0.02 0.8449 X-Sect 2.6909 - 92.2 31.5642 491.48 0.06 0.5117 X-Sect 2.2214 ---- 92.2 31.4314 3470.27 0.01 0.541 X-Sect 1.1469 ---- 92.2 31.2367 549.84 0.06 0.5301 X-Sect 0.8959 -- 92.2 31.1967 3827.85 0.01 0.6298 X-Sect 2.5886 --- 92.2 31.1607 4.3371 7.18 -1 12" Diam 7.1847 5.5221 92.2 31.1444 50.2681 0.62 1.5106 X-Sect 3.8005 -- 122.6 39.4139 594.02 0.07 0.527 X-Sect 15.3819 ----e-006 122.6 39.3717 15.3148 2.57 -1 18" Diam 2.5708 8.6664 122.6 39.1738 18.2879 2.14 ,1 X-Sect 2.1421 ---- 122.6 39.0873 17.5281 2.23 -1 X-Sect 2.23 -- 122.6 39.0705 179.94 0.22 0.7996 X-Sect 7.5336 .. ---- 122.6 39.0498 61.1492 0.64 1.7492 X-Sect 4.2208 - 122.6 38.9434 27.9865 1.39 -1 X-Sect 1.3915 --- 122.6 38.9414 78.2241 0.5 2.0557 X-Sect 5.829 -- 122.6 38.9219 30.6525 1.27 -1 24" Diam 1.2698 9.757 122.6 38.8904 47.75 0.81 1.8838 X-Sect 6.0508 --- 124.4 39.2371 319.76 0.12 1.298 X-Sect 8.3113 --- 124.4 39.225 1134.16 0.03 0.9129 X-Sect 8.7019 - 124.4 39.1846 413.21 0.09 1.4411 X-Sect 5.2991 ---- e-007 ·1 D-110 124.4 39.1518 241.55 0.16 1.3552 X-Sect 5.6219 --- Reh App Bend Junct HW Max El/ Loss Head Loss Loss Elev Rim El Fr Node To Node ft ft ft ft ft ft N-110 408.9452 N-111 N-110 409.8951 -na--na---na--409.8951 411.92 N-112 N-111 411.0111 -na---na----na-411.0111 414.13 N-113 N-112 412.691 -na--na----na--412.691 415.64 N-114 N-113 413.3009 --na---na----na--413.3009 415.67 N-115 N-114 415.03 --na--na--na-414.18 414.08 N-116 N-115 416.0292 -na--na--na-416.0292 416.5 N-117 N-116 416.3256 -na--na--na-416.3256 416.39 N-118 N-117 417.1555 -na---na--na-416.49 416.39 N-119 N-118 417.1629 -na---na---na-416.71 416.61 N-120 N-119 418.4399 -na---na---na-418.24 418.14 N-121 N-120 420.9399 --na----na---na--420.43 420.33 N-122 N-121 421.696 --na----na----na-421.696 422.69 N-123 N-122 437 .3544 --na---na----na--423.41 423.31 N-124 N-123 426.0499 -na--na---na--423.41 423.31 N-125 N-124 423.6805 --na----na----na-423.6805 424.05 · N-126 N-125 524.8533 -na---na---na-424.9 424.8 N-127 N-126 425.6399 -na----na---na-425.6399 426.02 N-128 N-127 426.0798 -na---na---na-426.0798 426.52 N-129 N-128 427.6098 -na--na---na-427.6097 428.27 N-130 N-129 429.6497 -na----na--na-429.4 429.3 N-131 N-130 430.9699 -na--na----na-430.83 430.73 N-132 N-131 432.5633 --na----na---na--432.5633 432.79 N-133 N-132 439.3671 -na---na----na-436.5 436.4 N-134 N-133 436.5119 --na---na---na--436.03 435.93 N-135 N-134 437.85 -na---na---na-437.57 437.47 N-136 N-135 440.3899 --na--na--na--440.25 440.15 N-137 N-136 445.4762 -na----na---na--442.2 442.1 N-137A N-137 442.8699 --na----na----na-441.99 441.89 N-138 N-137A 483.6605 -na--na---na--442.9 442.8 N-139 N-138 443.6152 -na---na--na-442.9 442.8 N-140 N-139 443.8899 -na--na----na--443.14 443.04 N-141 N-140 444.4243 -na----na----na-444.4243 444.84 N-142 N-141 446.0716 -na---na---na--446.0716 446.11 N-143 N-142 447.2915 -na----na---na-447.2915 447.71 N-144 N-143 457.2313 -na---na---na-448.2 448.1 N-145 N-144 448.4599 --na---na--na-447.84 447.74 N-146 N-145 449.6399 -na---na---na-449.6399 449.84 N-147 N-146 452.3698 -na--nas--na-452.3698 452.71 N-148 N-147 . 453.5398 -na---na--na-453.5398 453.89 N-149 N-148 479.5756 --na---na---na-454.3 454.2 N-150 N-149 454.3031 --na--na---na-454.3031 454.65 N-151 N-150 456.413 --na---na----na-455.87 455.77 N-.152 N-151 460.6481 -na-s -na---na--460.56 460.46 '1-153 N-152 464.0445 --na---na---na-464.0445 464.17 ,-154 N-153 467 .9954 --na----na--na--467.44 467.34 Table B.6. Hydrograph Routing -East Basin -Summary Table 2-Year 10-Year 25-Year 50-Year 100-Year Freeboard ·Freeboard Freeooard Freeboard Freeboard Reach ID From Node To Node (FT} (FT) (FT) (FT) (FT) N-110 D-110 N-111 N-110 2.68 2.33 2.17 2.10 2.02 D-111 N-112 N-111 4.16 3.43 3.27 3.19 3.12 D-112 N-113 N-112 3.98 3.26 3.10 3.02 2.95 D-113 N-114 N-113 3.14 2.69 2.52 2.44 2.37 D-114 N-115 N-114 Overtop Overtop Overtop Overtop Overtop P-110 · N-116 N-115 1.00 Overtop Overtop 0.66 0.47 0-115 N-117 N-116 0.83 Overtop Overtop 0.16 0.06 D-116 N-118 N-117 0.00 Overtop Overtop Overtop Overtop D-117 N-119 N-118 Overtop Overtop Overtop Overtop Overtop D-118 N-120 N-119 Overtop Overtop Overtop Overtop Overtop D-119 N-121 N-120 Overtop Overtop Overtop Overtop Overtop D-120 N-122 N-121 1.17 1.36 1.17 1.08 0.99 P-111 N-123 N-122 0.32 Overtop Overtop Overtop Overtop D-121 N-124 N-123 Overtop Overtop Overtop Overtop Overtop D-122 N-125 N-124 0.41 0.41 0.41 0.41 0.37 P-112 N-126 N-125 Overtop Overtop Overtop Overtop Overtop 0-123 N-127 N-126 0.38 0.38 0.38 0.38 0.38 D-124 N-128 N-127 0.44 0.44 0.44 0.44 0.44 0-125 N-129 N-128 0.66 0.66 0.66 0.66 0.66 D-126 N-130 N-129 Overtop Overtop Overtop Overtop Overtop 0-127 N-131 N-130 Overtop Overtop Overtop Overtop Overtop D-128 N-132 N-131 0.34 0.34 0.34 0.29 0.23 P-113 N-133 N-132 Overtop Overtop Overtop Overtop overtop D-129 N-134 N-133 Overtop Overtop Overtop Overtop Overtop D-130 N-135 N-134 Overtop Overtop Overtop Overtop Overtop D-131 N-136 N-135 Overtop Overtop Overtop Overtop Overtop P-114 N-137 N-136 0.68 Overtop Overtop Overtop Overtop D-132 N-137A N-137 Overtop Overtop Overtop Overtop Overtop P-115 N-138 N-137A Overtop Overtop Overtop Overtop Overtop D-133 N-139 N-138 Overtop Overtop Overtop Overtop Overtop D-133A N-140 N-139 Overtop Overtop Overtop Overtop OVertop D-134 N-141 N-140 0.44 0.44 0.44 0.44 0.42 0-135 N-142 N-141 0.44 0.32 0.17 0.10 0.04 D-136 N-143 N-142 0.82 0.70 0.55 0.48 0.42 P-116 N-144 N-143 Overtop Overtop Overtop Overtop Overtop 0-137 N-145 N-144 Overtop OVertop Overtop Overtop Overtop D-138 N-146 N-145 0.20 0.20 0.20 0.20 0.20 D-139 N-147 N-146 0.34 0.34 0.34 0.34 0.34 0-140 N-148 N-147 0.35 0.35 0.35 0.35 0.35 P-117 N-149 N-148 Overtop Overtop Overtop Overtop Overtop D-141 N-150 N-149 0.35 0.35 0.35 0.35 0.35 D-142 N-151 N-150 Overtop Overtop Overtop Overtop Overtop D-143 N-152 N-151 Overtop Overtop Overtop Overtop Overtop D-144 N-153 N-152 0.28 0.28 0.27 0.20 0.13 D-145 N-154 N-153 Overtop Overtop Overtop Overtop Overtop Table B.7. Hydrograph Routing -West Basin -2-Year Storm ROUTEHYD O THRU [Existing West) USING TYPE1A AND [2 yr) NOTZERO ACTUAL. Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin / Hyd D-021 D-020 P-016 D-019 D-018 P-015 0-017 0-016 P-014 D-015 D-014 P-013 D-012 0-011 0-010 P-012 P-011 P-010 P-009 P-008A P-008 P-007 P-006 P-005 P-004 D-009 0-008 P-003 0-007 D-006 P-002 D-005 0-004 D-003 D-002 D-001 P-001 ac cfs cfs ratio ft tus ft/s 2.9 0.5767 215.99 0 0.3321 X-Sect 3.0535 ---w-001 2.9 0.5766 75.0242 0.01 0.3244 X-Sect 2.7143 •••.• 19.2 2.8102 10.5228 0.27 0.3529 12'" Diam 11.3425 13.398 w-002 19.2 2.8096 212.76 0.01 0.6667 X-Sect 4.1816 -·- 21.1 3.0333 251 .93 0.01 0.2382 X-Sect 5.8108 --ex_west 21.1 3.0325 7.7298 0.39 0.4351 12" Diam 9.2462 9.8418 21.1 3.0318 138.18 0.02 0.3561 X-Sect 3.5277 -- 21.1 3.0316 452.04 0.01 0.254 X-Sect 5.0894 - 22.3 3.2439 7.9881 0.41 0.4436 12" Diam 9.6423 10.1708 w-003 22.3 3.2432 160.64 0.02 0.451 X-Sect 3.7541 -- 22.3 3.2429 200 0.02 0.6317 X-Sect 4.3238 -- 22.3 3.2423 10.6228 0.31 0.3791 12" Diam 11.8787 13.5253 22.3 3.2413 290.67 0.01 0.6234 X-Sect 4.8101 - 22.3 3.2403 320.43 0.01 0.3609 X-Sect 4.0339 -- 25.5 3. 7564 1040.88 0 0.5771 X-Sect 6.1421 ---w-004 25.5 3.7551 7.0631 0.53 0.5186 12'" Diam 9.1309 8.9931 25.5 3.7536 6.9402 0.54 0.5239 12" Diam 9.0097 8.8365 25.5 3.7521 8.217 0.46 0.4742 12" Diam 10.2249 10.4623 25.5 3.7507 7.6431 0.49 0.4945 12" Diam 9.6859 9.7315 27.7 4.1444 4.8684 0.85 0.709 12" Diam 6.9597 6.1986 w-005 31.5 4.8063 6.8722 0.7 0.6161 12" Diam 9.4657 8.75 w-006 31.5 4.8057 6.4104 0.75 0.6459 12" Diam 8.9569 8.162 31.5 4.8039 7.4569 0.64 0.5839 12" Diam 10.0875 9.4945 39.3 6.248 9.9629 0.63 0.574 12" Diam 13.3954 12.6852 w-007 39.3 6.2406 7.7824 0.8 0.6778 12" Diam 11.0133 9.9088 39.3 6.2233 93.993 0.07 0.6278 X-Sect 2.79 -- 39.3 6.2231 112.96 0.06 0.414 X-Sect 6.2056 •••·• 39.3 6.2205 6.2952 0.99 0.8091 12" Diam 9.1373 8.0153 39.3 6.2079 107.57 0.06 0.5256 X-Sect 3.8357 -- 39.3 6.2077 964.56 0.01 0.3936 X-Sect 8.1166 - 39.3 6.204 6.1462 1.01 0.8284 12" Diam 8.9179 7.8256 39.3 6.2035 --· 0 0.915 X-Sect 2.1497 --- 39.3 6.1864 44.3354 0.14 0.5256 X-Sect 4.8288 -- 39.3 6.1853 313.41 0.02 0.5341 X-Sect 4.3358 - 39.3 6.1799 770.99 0.01 0.6454 X-Sect 1.5651 -- 39.3 6.1797 146.32 0.04 0.4209 X-Sect 7.1705 --- .48.3 6. 7994 8.2043 0.83 0.6946 12" Diam 11.6778 10.4461 w-008 Reh App Bend June! HW Loss Head Loss Loss Elev From Nod To Node ft ft ft ft ft Max El/ Rim El ft N-002 N-003 '11-004 .~-005 N-001 373.6321 N-001 382.2466 -na- N-002 381.0999 --na-'- N-003 382.8899 --na-- N-004 389.8769 -na- -na-- --na- --na- -na- --na- -na- -na-- -na- 380.5 380.43 382.3 389.8769 380.4 380.33 382.2 390.25 ' ., N-006 N-005 398.3768 --na---na----na--398.3768 398.68 N-007 N-006 397. 7699 --na----na----na--397.7699 398.68 N-008 N-007 400.6486 --na----na----na-399.4 ·399.3 N-010 N-008 400.3799 --na----na----na--399.4 399.3 N-011 N-010 400.4899 --na---na----na-400.32 400.22 N-012 N-011 403.3211 --na---na----na--401.7 401.6 N-014 N-012 401.9299 --na----na----na-401.9 401.8 N-015 N-014 402.4099 --na----na----na--402.4099 402.6 N-016 N-015 406.8691 0.9827 0. 0089 ------405.8952 406.01 N-017 N-016 407.6445 0.5809 0.0075 ------406.41 406.31 N-018 N-017 408.2272 0.5814 0.0023 ----407.6481 408.14 N-019 N-018 411 . 1539 ------411.1539 413.72 N-019A N-019 419.722 0.4324 0.0032 --419.2928 420.68 N-020 N-019A 420.102 ---420.102 422.5 N-021 N-020 428.8048 0.3544 0.0039 --428.4543 429.85 N-022 N-021 431.8735 1.2605 0.0049 -----430.6179 434 N-023 N-022 435.9002 0.355 0.0013 ----435.5465 436.59 N-024 N-023 437.2402 --na----na----na--437.2402 438.2 N-025 N-024 437.6302 --na---na----na--437.6302 438.9 N-026 N-025 440.4301 --na----na----na--440.4301 441.52 N-028 N-026 444.3401 --na----na----na--444.3401 444.82 N-029 N-028 445.7641 --na---na----na-445.764 446.2 N-031 N-029 445.934 -na--na--na-445.934 446.47 N-032 N-031 447.8239 -na---na---na-447.8239 449.01 N-033 N-032 448.994 --na---na--na-448.994 450.1 N-035 N-033 449.4039 -na----na---na--449.4039 451.24 N-036 N-035 451.6238 -na--· --na---na-451.6238 452.98 N-037 N-036 452.5651 --na---na----na-452.5651 453.8 N-039 N-037 453.065 --na----na----na--453.065 454.27 N-040 N-039 455.835 --na----na----na--455.835 457.02 N-041 N-040 458.6864 --na----na---na-458.6864 459.3 N-043 N-041 458.8464 --na----na----na-458.8463 459.71 N-044 N-043 466. 1862 -na----na---na--466.1862 467.86 Table B.8. Hydrograph Routing -West Basin -10-Year Stonn ROUTEHYD [] THRU [Existing West] USING TYPE1A AND [10 yr) NOTZERO ACTUAL Reach Area Flow Full Q % Full nOepth Size nVel Nel CBasin / Hyd D-021 D-020 P-016 D-019 D-018 P-015 D-017 D-016 P-014 D-015 D-014 P-013 0-012 D-011 D-010 P-012 P-011 P-010 P-009 P-008A P-008 P-007 P-006 P-005 P-004 D-009 D-008 P-003 0-007 0-006 P-002 D-005 D-004 D-003 D-002 D-001 P-001 ac cfs cfs ratio ft ft/s ft/s 2.9 1.1262 215.99 0.01 0.4269 X-Sect 3.6099 --w-001 2.9 1.126 75.0242 0.02 0.417 X-Sect 3.2085 --- 19.2 5.7252 10.5228 0.54 0.5258 12" Diam 13.6802 13.398 w-002 19.2 5.7243 212.76 0.03 0.8706 X-Sect 4.9958 -- 21.1 6.2369 251.93 0.02 0.3597 X-Sect 7.2932 -ex_west 21.1 6.2355 7.7298 0.81 0.6807 12" Diam 10.9508 9.8418 21.1 6.2346 138.18 0.05 0.5336 X-Sect 4.3923 - 21.1 6.2343 452.04 0.01 0.3664 X-Sect 6.4244 - 22.3 6.6546 7.9881 0.83 0.6973 12" Diam 11.3797 10.1708 w-003 22.3 6.6534 160.64 0.04 0.6285 X-Sect 4.6707 ---- 22.3 6.653 200 0.03 0.827 X-Sect 5.1746 --- 22.3 6.652 10.6228 0.63 0.5735 12" Diam 14.2771 13.5253 22.3 6.6504 290.67 0.02 0.8162 X-Sect 5.757 -- 22.3 6.6488 320.43 0.02 0.516 X-Sect 5.0632 - 25.5 7.6794 1040.88 0.01 0.7546 X-Sect 7.3444 ---w-004 25.5 7.6772 7.0631 1.09 -1 12" Diam 1.0869 8,9931 25.5 7.6747 6.9402 1.11 -1 12" Diam 1.1058 8.8365 25.5 7.6721 8.217 0.93 0.7657 12" Diam 11.8884 10.4623 25.5 7.6702 7.6431 1 0.8229 12" Diam 11.0927 9.7315 27.7 8.4447 4.8684 1.73 -112"Diam 1.7346 6.1986 w-005 31.5 9.6483 6.8722 1.4 -1 12" Diam 1 .404 8. 75 w-006 31.5 9.6459 6.4104 1.5 -1 12" Diam 1.5047 8.162 31.5 9.6425 7.4569 1.29 -1 12" Diam 1.2931 9.4945 39.3 12.2397 9.9629 1.23 -1 12· Diam 1.2285 12.6852 w-007 39.3 12.2337 7.7824 1.57 -1 12" Diam 1.572 9.9088 39.3 12.2305 93.993 0.13 0.867 X-Sect 3.43 -- 39.3 12.2302 112.96 0.11 0.5807 X-Sect 7.6019 -- 39.3 12.2269 6.2952 1.94 -1 12" Diam 1.9423 8.0153 39.3 12.2225 107.57 0.11 0.7439 X-Sect 4.7079 -- 39.3 12.2223 964.56 0.01 0.5074 X-Sect 9.6143 --- 39.3 12.2172 6.1462 1.99 -1 12" Diam 1.9878 7.8256 39.3 12.2169 -0 0.915 X-Sect 4.2335 ---- 39.3 12.207 44.3354 0.28 0.7349 X-Sect 5.8637 --- 39.3 12.1945 313.41 0.04 0.7226 X-Sect 5.3815 - 39.3 12.1624 770.99 0.02 0.7234 X-Sect 1.7335 - 39.3 12.1621 146.32 0.08 0.5527 X-Sect 8.9201 -- .48.3 13.7386 8.2043 1.67 -1 12" Diam 1.6746 10.4461 w-008 Reh Loss App Head From Nod To Node fl fl Bend Loss fl Junct Loss fl HW Elev fl Max EV Rim El fl N-002 N-003 J-004 N-005 N-001 N-001 N-002 N-003 N-004 373.66 397.4953 -na- 381.0999 -na- 382.8899 -na- 390.363 --na-- -na---na-- -na--na- -na--na-- -na----na- 380.5 380.43 382.3 390.35 380.4 380.33 382.2 390.25 •1 N-006 N-005 398.8499 --na----na----na--398.78 398.68 N-007 N-006 398.1499 --na----na----na--398.1499 398.68 N-008 N-007 406.7091 --na----na----na--399.4 .. 399.3 N-010 N-008 400.3799 --na----na----na--399.4 399.3 N-011 N-010 400.4899 --na----na----na--400.32 400.22 N-012 N-011 402.893 -'na----na---na--401.7 401.6 N-014 N-012 401. 9299 -na----na---na--401.9 401.8 N-015 N-014 402.4099 -na----na----na--402.4099 402.6 N-016 N-015 414.9783 3.7712 0. 0341 ------406.11 406.01 N-017 N-016 412.823 2.3405 0.0303 ------406.41 406.31 N-018 N-017 412.9798 2.3422 0.0092--408.24 408.14 N-019 N-018 421.5153-. 413.82 413.72 N-019A N-019 428.7839 1.7952 0.0134 ---420.78 420.68 N-020 N-019A 424.1394 --422.6 422.5 N-021 N-020 431.693 1.4817 0.0162 ------429.95 429.85 N-022 N-021 431.8735 1.4827 0.0057 -----· 430.3965 434 N-023 N-022 438.0848 1.4837 0.0053 ------436.69 436.59 N-024 N-023 440.4391 --na----na----na--438.3 438.2 N-025 N-024 438.69 --na--na----na--438.69 438.9 N-026 N-025 441 .4899 -na---na----na-441.4899 441.52 N-028 N-026 445.3998 --na----na----na--444.92 444.82 N-029 N-028 447.9408 .--na----na---na--446.3 446.2 N-031 N-029 446.47 --na---na----na-446.47 446.47 N-032 N-031 448.3599 --na--na--na-448.3599 449.01 N-033 N-032 451.1722 -na--na---na-450.2 450.1 N-035 N-033 450.6099 --na---na--na-450.6099 451.24 N-036 N-035 452.8299 --na---na---na-452.8299 452.98 N-037 N-036 454.9681 --na----na---na-453.9 453.8 N-039 N-037 454.3999 --na----na----na-454.37 454.27 N-040 N-039 457 .14 --na----na----na-457.12 457.02 N-041 N-040 460.2915 --na--na---na--459.4 459.3 N-043 N-041 459 .5599 --na---na----na--459.5599 459.71 N-044 N-043 466.8998 --na----na---na--466.8998 467.86 :, Table B.9. Hydrograph Routing -West Basin -25-Year Storm ROUTEHYD [] THRU [Existing West] USING TYPE1A AND [25 yr) NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin / Hyd D-021 0-020 P-016 D-019 D-018 P-015 D-017 0-016 P-014 D-015 D-014 P-013 D-012 0-011 D-010 P-012 P-011 P-010 P-009 P-008A P-008 P-007 P-006 P-005 P-004 D-009 D-008 P-003 0-007 0-006 P-002 D-005 0-004 Dc003 D-002 D-001 P-001 ac cfs cfs ratio fl · · tus tus 2.9 1.4193 215.99 0.01 0.4655 X-Sect 3.8249 --w-001 2.9 1.419 75.0242 0.02 0.4548 X-Sect 3.3995 -- 19.2 7.2941 10.5228 0.69 0.6125 12" Diam 14.4658 13.398 w-002 19.2 7.2903 212.76 0.03 0.9533 X-Sect 5.3071 ---- 21.1 7.9622 251.93 0.03 0.4124X-Sect 7.8517----ex_west 21.1 7.9606 7.7298 1.03 0.8494 12" Diam 11.1952 9.8418 21.1 7.9596 138.18 0.06 0.6103 X-Sect 4.7161 - 21.1 7.9593 452.04 0.02 0.4154 X-Sect 6.9302- 22.3 8.4903 7.9881 1.06 0.8943 12" Diam 11.4571 10.1708 w-003 22.3 8.4889 160.64 0.05 0.7052 X-Sect 5.0142 - 22.3 8.4884 200 0.04 0.9062 X-Sect 5.4996 -- 22.3 8.4872 10.6228 0.8 0.676 12" Diam 15.0227 13.5253 22.3 8.4854 290.67 0.03 0.8943 X-Sect 6.1186 ---- 22.3 8.4835 320.43 0.03 0.5836 X-Sect 5.4511 ---· 25.5 9.7892 1040.88 0.01 0.8265 X-Sect 7.8039 ---w-004 25.5 9.7867 7.0631 1.39 -1 12" Diam 1.3856 8.9931 25.5 9.7842 6.9402 1.41 -1 12" Diam 1.4098 8.8365 25.5 9.7811 8.217 1.19 -1 12" Diam 1.1903 10.4623 25.5 9.7791 7.6431 1.28 -1 12" Diam 1.2795 9.7315 27.7 10.7564 4.8684 2.21 -1 12" Diam 2.2095 6.1986 w-005 31.5 12.2532 6.8722 1.78 -1 12"Diam 1.783 8.75 w-006 31.5 12.2295 6.4104 1.91 -1 12" Diam 1.9077 8.162 31.5 12.214 7.4569 1.64 -1 12" Diam 1.6379 9.4945 39.3 15.4537 9.9629 1.55 -1 12" Diam 1.5511 12.6852 w-007 39.3 15.439 7.7824 1.98 -1 12" Diam 1.9838 9.9088 39.3 15.4332 93.993 0.16 0.9703 X-Secl 3.6728 - 39.3 15.4329 112.96 0.14 0.6524 X-Sect 8.1307 ---- 39.3 15.4277 6.2952 2.45 -1 12" Diam 2.4507 8.0153 39.3 15.4211 107.57 0.14 0.8378 X-Sect 5.0372 ---· 39.3 15.4209 964.56 0.02 0.5537 X-Sect 10.1896 -· 39.3 15.4136 6.1462 2.51 -1 12" Diam 2.5078 7.8256 39.3 15.4133 ---0 0.915 X-Sect 5.3412 -- 39.3 15.3973 44.3354 0.35 0.8232 X-Sect 6.2522 ---- 39.3 15.3784 313.41 0.05 0.8043 X-Sect 5.7771 -- 39.3 15.3305 770.99 0.02 0.749 X-Sect 1.8482 -- 39.3 15.3302 146.32 0.1 0.61 X-Sect 9,5841 -- 48.3 17.4789 8.2043 2.13 -1 12" Diam 2.1304 10.4461 w-008 Reh Loss Max El/ · Rim El From Nod To Node fl App Head fl Bend Loss fl June! Loss fl HW Elev fl fl N-002 N-003 N-004 N-005 N-001 N-001 N-002 N-003 N-004 373.66 412.2399 --na-- 381.1 --na- 382.8899 -na- 390.6017 -na- -na-- --na- -na,- --na-- --na-- -na- -na- -na- 380.5 380.43 382.3 390.35 380.4 380.33 382.2 390.25 , .'1 N-006 N-005 398.85 --na----na---na-398.78 398.68 N-007 N-006 398.1499 --na----na----na-398.1499 398.68 N-008 N-007 411. 7735 --na----na----na-399.4 399.3 N-010 N-008 400.3799 --na----na----na--399.4 399.3 .. N-011 N-010 400.4899 --na---:na----na--400.32 400.22 N-012 N-011 404.2625 --na----na-~ --na--401.7 401.6 N-014 N-012 401.9299 --na---na----na-401.9 401.8 N-015 N-014 402.4099 --na----na----na--402.4099 402.6 N-016 N-015 422.4271 6.0118 0. 0544 ------406.11 406.01 N-017 N-016 416.8114 3.7554 0. 0486 ------406.41 406.31 N-018 N-017 416.9514 3.7649 0.0148 --408.24 408.14 Ns019 N-018 429.5789 ----413.82 413.72 N-019A N-019 437.9548 2.9125 0.0218 ---420.78 420.68 N-020 N-019A 426.2303--422.6 422.5 N-021 N-020 436.8487 2.4083 0.0264 -----429.95 429.85 N-022 N-021 438.8036 2.4098 0. 0093 ------434.1 434 N-023 N-022 442.3643 2.4111 0.0087 --436.69 436.59 N-024 N-023 442.7826 --na----na----na--438.3 438.2 N,025 N-024 438.69 --na----na----na--438.69 438.9 N-026 N-025 441.4899 -na----na----na-441.4899 441.52 N-028 N-026 445.3998 --ria----na----na--444.92 444.82 N-029 N-028 449. 7335 --na----na----na-446.3 446.2 N-031 N-029 446. 4 7 --na----na--na--446.47 446.47 N-032 N-031 448.3599 --na----na---na--448.3599 449.01 N-033 N-032 452.966 -na---na--na-450.2 450.1 N-035 N-033 450.6099 --na---na---na-450.6099 451.24 N-036 N-035 452.8299 -na---na---na-452.8299 452.98 N-037 N-036 456.3148 -na---na--na-453.9 453.8 N-039 N-037 454.3999 -na----na--na--454.37 454.27 N-040 N-039 457.1399 --na----na---na--457.12 457.02 N-041 N-040 461.6094 -na----na----na-459.4 459.3 N-043 N-041 459.5599 -na----na--na-459.5599 459.71 N-044 N-043 466.8998 --na---na----na--466.8998 467.86 ) Table 8.10. Hydrograph Routing -West Basin -50-Year Stonn ROUTEHYD [] THRU [Existing West) USING TYP!=1A AND [50 yr] NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin / Hyd D-021 D-020 P-016 D-019 D-018 P-015 D-017 D-016 P-014 D-015 D-014 P-013 D-012 D-011 D-010 P-012 P-011 P-010 P-009 P-008A P-008 P-007 P-006 P-005 P-004 D-009 D-008 P-003 D-007 D-006 P-002 D-005 D-004 D-003 D-002 D-001 P-001 ac els els ratio ft · · fUs fUs 2.9 1.5685 215.99 0.01 0.4833 X-Sect 3.9215 ---w-001 2.9 1.5683 75.0242 0.02 0.4722 X-Sect 3.4853 --- 19.2 8.0999 10.5228 0.77 0.6581 12' Diam 14.7787 13.398 w-002 19.2 8.0896 212.76 0.04 0.9912 X-Sect 5.4469 --- 21.1 8.8435 251.93 0.04 0.4372 X-Sect 8.1008---ex_west 21.1 8.8417 7.7298 1.14 -1 12" Diam 1.1439 9.8418 21.1 8.8407 138.18 0.06 0.6463 X-Sect 4.8603 -- 21.1 8.8404 452.04 0.02 0.4384 X-Sect 7.156 --- 22.3 9.434 7.9881 1.18 -1 12"Diam 1.181 10.1708 w-003 22.3 9.4262 160.64 0.06 0.7412 X-Sect 5.1673 -- 22.3 9.4257 200 0.05 0.9425 X-Sect 5.6454 ---- 22.3 9.4245 10.6228 0.89 0.7329 12" Diam 15.2781 13.5253 22.3 9.4224 290.67 0.03 0.9301 X-Sect 6.2809 ---- 22.3 9.4204 320.43 0.03 0.6154 X-Sect 5.6241 --- 25.5 10.8663 1040.88 0.01 0.8595 X-Sect 8.0101 -w-004 25.5 10.8659 7.0631 1.54 -1 12" Diam 1.5384 8.9931 25.5 10.8622 6.9402 1.57 -1 12" Diam 1.5651 8.8365 25.5 10.8581 8.217 1.32 -1 12" Diam 1.3214 10.4623 25.5 10.8544 7.6431 1.42 -1 12" Diam 1.4201 9.7315 27.7 11.9326 4.8684 2.45 -1 12" Diam 2.4511 6.1986 w-005 31.5 13.5621 6,8722 1.97 -1 12' Diam 1.9735 8.75 w-006 31.5 13.5297 6.4104 2.11 -112"Diam 2.1106 8.162 31.5 13.5123 7.4569 1.81 -1 12" Diam 1.8121 9.4945 39.3 17.0801 9.9629 1.71 -1 12" Diam 1.7144 12.6852 w-007 39.3 17.0634 7.7824 2.19 -1 12" Diam 2.1926 9.9088 39.3 17.0568 93.993 0.18 1.0185 X-Sect 3.7809 -- 39.3 17.0564 112.96 0.15 0.6858 X-Sect 8.366 - 39.3 17.0509 6.2952 2.71 -1 12" Diam 2.7086 8.0153 39.3 17.0435 107.57 0.16 0.8816 X-Sect 5.1838 ---- 39.3 17.0432 964.56 0.02 0.5748 X-Sect 10.4477 -- 39.3 17.0355 6.1462 2.77 -1 12' Diam 2.7717 7.1!256 39.3 17.0353 --0 0.915 X-Sect 5.9032 - 39.3 17.0172 44.3354 0.38 0.8642 X-Sect 6.4254 - 39.3 16.9961 313.41 0.05 0.8428 X-Sect 5.9539 -- 39.3 16.9427 770.99 0.02 0.7591 X-Sect 1.9232 - 39.3 16.9424 146.32 0.12 0.6369 X-Sect 9.8817 -- 48.3 19.3916 8.2043 2.36 -1 12" Diam 2.3636 10.4461 w-008 Reh Loss From Nod To Node fl App Head fl Bend Loss fl Junct - LOSS fl HW Elev fl Max El/ Rim El fl N-002 N-003 N-004 N-005 N-001 N-001 N-002 N-003 N-004 373.66 421.1453 -na-- 381.1 -na-- 382.8899 -na- 390.6621 --na- -na---na- -na---na- -na--na- -na--na- 380.5 380.43 382.3 390.35 380.4 380.33 382.2 390.25 N-006 N-005 398.8499 --na----na----na--398.78 398.68 N-007 N-006 398.1499 --na--na----na--398.1499 398.68 N-008 N-007 414.7916 --na----na-, ·--na--399.4 ·399.3 N-010 N-008 400.3799 --na----na--.--na--399.4 399.3 N-011 N-010 400.5191 --na----na----na--400.32 400.22 N-012 N-011 405.0781 --na----na----na--401.7 401.6 N-014 N-012 401.9299 --na----na----na--401.9 401.8 N-015 N-014 402.4099 --na----na----na--402.4099 402.6 N-016 N-015 426.8611 7.3437 0.0665 -----406.11 406.01 N-017 N-016 419.1824 4.5962 0.0595 ----406.41 406.31 N-018 N-017 419.3115 4.6079 0.0181 -408.24 408.14 N-019 N-018 434.3575 ---. 413.82 413.72 N-019A N-019 443.3864 3.5843 0.0268 ----420.78 420.68 N-020 N-019A 427 .4875 ----422.6 422.5 N-021 N-020 440.1545 2.9679 0. 0325 ------429.95 429.85 N-022 N-021 440.8607 2.9701 0.0115 ------434.1 434 N-023 N-022 444.2857 2.9721 0.0107 ---436.69 436.59 N-024 N-023 444.2004 --na----na----na--438.3 438.2 N-025 N-024 438.6899 --na---na----na--438.6899 438.9 N-026 N-025 441.4899 -na---na---na--441.4899 441.52 N-028 N-026 445.3998 -na----na----na--444.92 444.82 N-029 N-028 450.8166 -na--na----na--446.3 446.2 N-031 N-029 446.47 -na---na----na--446.47 446.47 N-032 N-031 448.3599 -na--na---na--448.3599 449.01 N-033 N-032 453.324 -na--na---na-450.2 450.1 ~-035 N-033 450.6099 -na---na----na-450.6099 451.24 N-036 N-035 452.8299 --na----na----na-452.8299 452.98 N-037 N-036 457.129 --na----na----na--453.9 453.8 N-039 N-037 454.3999 --na----na----na--454.37 454.27 N-040 N-039 457.1399 --na---na----na-457.12 457.02 N-041 N-040 462.4097 --na----na----na-459.4 459.3 N-043 N-041 459.5599 --na--na----na--459.5599 459.71 N-044 N-043 466.8998 --na----na----na--466.8998 467.86 Table 8.11. Hydrograph Routing -West Basin -100-Year Stonn ROUTEHYD O THRU [Existing West] USING TYPE1A AND [100 yr] NOTZERO ACTUAL Reach Area Flow Full Q % Full nDepth Size nVel Nel CBasin / Hyd D-021 D-020 P-016 D-019 D-018 P-015 D-017 D-016 P-014 D-015 D-014 P-013 D-012 D-011 D-010 P-012 P-011 P-010 P-009 P-008A P-008 P-007 P-006 P-005 P-004 D-009 D-008 P-003 0-007 0-006 P-002 D-005 D-004 D-003 0-002 0-001 P-001 ac cfs cfs ratio ft ft/s fl/s 2.9 1.7191 215.99 0.01 0.5002 X-Sect 4.0124 ---w-001 2.9 1.7188 75.0242 0.02 0.4887-X-Sect 3.5662 --- 19.2 8.9147 10.5228 0.85 0.7064 12" Diam 15.0315 13.398 w-002 19.2 8.8982 212.76 0.04 1.0272 X-Sect 5.5783 ---- 21.1 9.7341 251.93 0.04 0.4611 X-Sect 8.3334 ---ex_west 21.1 9.7323 7.7298 1.26 -1 12" Diam 1.2591 9.8418 21.1 9.7313 138.18 0.07 0.6809 X-Sect 4.9949 - 21.1 9.7309 452.04 0.02 0.4605 X-Sect 7.3672 - 22.3 10.3918 7.9881 1.3 -1 12" Diam 1.3009 10,1708 w-003 22.3 10.3745 160.64 0.06 0.7757 X-Sect 5.3102 --- 22.3 10.3736 200 0.05 0.977 X-Sect 5.7823 -- 22.3 10.3718 10.6228 0.98 0.7991 12" Diam 15.4151 13.5253 22.3 10.3694 290.67 0.04 0.9642 X-Sect 6.4331 ---- 22.3 10.3672 320.43 0.03 0.6459 X-Sect 5.7856 --- 25.5 11.9547 1040.88 0.01 0.8908 X-Sect 8.2036 -w-004 25.5 11.9546 7.0631 1.69 -1 12" Diam 1.6925 8.9931 25.5 11.9518 6.9402 1.72 -1 12" Diam 1.7221 8.8365 25.5 11.9391 8.217 1.45 -1 12" Diam 1.453 10.4623 25.5 11.8994 7 .6431 1.56 -1 12" Diam 1.5569 9.7315 27.7 13.0768 4.8684 2.69 -1 12" Diam 2.6861 6.1986 w-005 31.5 14.8216 6.8722 2.16 -1 12" Diam 2.1567 8.75 w-006 31.5 14.7641 6.4104 2.3 -1 12" Diam 2.3031 8.162 31.5 14.7397 7.4569 1.98 -1 12" Diam 1.9766 9.4945 39.3 18.6376 9.9629 1.87 -1 12" Diam 1.8707 12.6852 w-007 39.3 18.6131 7.7824 2.39 -1 12" Diam 2.3917 9.9088 39.3 18.6037 93.993 0.2 1.0612 X-Sect 3.8828 - 39.3 18.6034 112.96 0.16 0.7161 X-Sect 8.5744 - 39.3 18.5959 6.2952 2.95 -1 12" Diam 2.954 8.0153 39.3 18.5866 107.57 0.17 0.9214 X-Sect 5.3133 - 39.3 18.5863 964.56 0.02 0.5938 X-Sect 10.6766 -- 39.3 18.5762 6.1462 3.02 -1 12" Diam 3.0224 7.8256 39.3 18.576 --0 0.915 X-Sect 6.4371 ----- 39.3 18.5514 44.3354 0.42 0.9012 X-Sect 6.5778 - 39.3 18.5234 313.41 0.06 0.8774 X-Sect 6.1089 --- 39.3 18.4536 770.99 0.02 0.7682 X-Sect 1.9897 -- 39.3 18.4532 146.32 0.13 0.6611 X-Sect 10.141 --- 48.3 21.1994 8.2043 2.58 -1 12" Diam 2.5839 10.4461 w-008 Reh Loss From Nod To Node fl App Head fl Bend LOSS fl Junct Loss fl HW Elev fl Max El/ Rim El fl N-002 N-003 N-004 N-005 N-001 N-001 N-002 N-003 N-004 373.66 430.4121 --na-- 381.0999 -na~- 382.8899--na-- 390.6975 -na- -na- -na- -na- -na- --na-- --na- --na0 - -na- 380.5 380.43 382.3 390.35 380.4 380.33 382.2 390.25 .·l N-006 N-005 398.8499 -na---na----na-398.78 398.68 N-007 N-006 398.1499 -na----na----na--398.1499 398.68 N-008 N-007 417.9379 --na----.na----na--399.4 399.3 N-010 N-008 400.3799 --na----na--. --na--399.4 . 399.3 N-011 N-010 400.5711 --na----na--.--na--400.32 400.22 N-012 N-011 405.9302 --na----na----na--401.7 401.6 N-014 N-012 401.9299 -na----na----na--401.9 401.8 N-015 NC014 402.4099 --na--. --na---na--402.4099 402.6 N-016 N-015 431.5039 8.7441 . 0.0791 -----406.11 406.01 N-017 N-016 421.6752 5.469 0.0707 --406.41 406.31 N-018 N-017 421.7617 5.4872 0.0216-408.24 408.14 N-019 N-018 439.3409 --. 413.82 . 413.72 N-019A N.019 449.133 4.3046 0.0322--420.78 420.68 N-020 N-019A 428.8355-422.6 422.5 N-021 N-020 443.6975 3.5882 0.0393 ---429.95 429.85 N-022 N-021 443.1411 3.5959 0.0139 ----434.1 434 N-023 N-022 446.4317 3.5976 0.0129 -----436.69 436.59 N-024 N-023 445. 7808 --na---na----na--438.3 438.2 N-025 N-024 438.6899 --na----na---na--438.6899 438.9 N-026 N-025 441.4899 -na----na----na-441.4899 441.52 N-028 N-026 445.3998 --na----na---na--444.92 444.82 N-029 N-028 452.0266 --na---na----na-446.3 446.2 N-031 N-029 446.47 -na---na---na-446.47 446.47 N-032 N-031 448 .3599 --na--na--na-448.3599 449.01 N-033 N,032 454.3832 -na---na---na-450.2 450.1 .~-035 N-033 450.6099 -na--na---na-450.6099 451.24 N-036 N-035 452.8299 -na--na-· -na-452.8299 452:98 N-037 N-036 458.0387 -na--na----na--453.9 453.8 N-039 N-037 454 .3999 --na----na----na-454.37 454.27 N-040 N-039 457 .1399 --na----na----na-457.12 457.02 N-041 N-040 463.3042 --na----na--na-459.4 459.3 N-043 N-041 459.5599 -na----na---na-459.5599 459.71 N-044 N-043 466.8998 -na----na----na-466.8998 467.86 ., ) Table 8.12. Hydrograph Routing -West Basin -Summary Table 2-Year 10-Year 25-Year SO-Year 100-Year Freeboard Freeboard Freeboard Freeboard Freeboard Reach ID From Node To Node ft ft ft ft ft N-001 P-001 N-002 N-001 Overtop Overtop Overtop Overtop Overtop D-001 N-003 N-002 Overtop Overtop Overtop Overtop Overtop D-002 N-004 N-003 Overtop Overtop Overtop Overtop Overtop ·D-003 N-005 N-004 0.37 Overtop Overtop Overtop Overtop D-004 N-006 N-005 0.30 Overtop Overtop Overtop Overtop D-005 N-007 N-006 0.91 0.53 0.53 0.53 0.53 P-002 N-008 N-007 Overtop Overtop Overtop Overtop Overtop D-006 N-010 N-008 Overtop Overtop Overtop Overtop Overtop D-007 N-011 Ns010 Overtop Overtop Overtop Overtop Overtop P-003 N-012 N-011-Overtop Overtop Overtop Overtop Overtop D-008 N-014 N-012 Overtop Overtop Overtop Overtop· Overtop D-009 N-015 N-014 0.19 0.19 0.19 0.19 0.19 P-004 N-016 N-015 0.11 Overtop Overtop Overtop Overtop P-005 N-017 N-016 Overtop Overtop Overtop Overtop Overtop P-006 N-018 N-017 0.49 Overtop Overtop Overtop Overtop P-007 N-019 N-018 2.57 Overtop Overtop Overtop Overtop P-008 N-019A N-019 1.39 Overtop Overtop Overtop Overtop P-008A N-020 N-019A 2.40 Overtop Overtop Overtop Overtop P-009 N-021 N-020 1.40 Overtop Overtop Overtop Overtop P-010 N-022 N-021 3.38 3.60 Overtop Overtop Overtop P-011 N-023 N-022 1.04 Overtop Overtop Overtop Overtop P-012 N-024 N-023 0.96 Overtop Overtop Overtop Overtop D-010 N-025 N-024 1.27 0.21 0.21 0.21 0.21 D-011 N-026 N-025 1.09 0.03 0.03 0.03 0.03 D-012 N-028 N-026 0.48 Overtop Overtop Overtop Overtop P-013 N-029 N-028 0.44 Overtop Overtop Overtop Overtop D-014 N-031 N-029 0.54 0.00 0.00 0.00 0.00 D-015 N-032 N-031 1.19 0.65 0.65 0.65 0.65 P-014 N-033 N-032 1.11 Overtop Overtop Overtop Overtop D-016 N-035 N-033 1.84 0.63 0.63 0.63 0.63 D-017 N-036 N-035 1.36 0.15 0.15 0.15 0.15 P-015 . N-037 N-036 1.23 Overtop Overtop Overtop Overtop D-018 N-039 N-037 1.20 Overtop Overtop Overtop Overtop D-019 N-040 N-039 1.19 Overtop Overtop Overtop Overtop P-016 N-041 N-040 0.61 Overtop Overtop Overtop Overtop D-020 N-043 N-041 0.86 0.15. 0.15 0.15 0.15 D-021 N-044 N-043 1.67 0.96 0.96 0.96 0.96 ) ' Subsurface Explorat/<m and Preliminary Geotechnical Engineering Report . EVENDELL PRELIMINARY PLAT ,King County, Washington Prepared for U.S. Land Development Associates ·· Pn;iject No. K.EOI617 A · November 16, 2001 ) Associated Earth Sciences, Inc. November 16, 2001 Project No. KE01617A U.S. Land Development Associates c/o Centurion Development Services 22617 gm Drive SE Bothell, _Washington 98021 Attention: Mr. Mike Romano Subject: · Subsurface Exploration and Preliminary Geotechnical Engineering .Report Evendell Preliminary Plat SE Renton-Issaquah Road (SR 900) and 148m A venue SE · King County, Washington De<1r Mr. Rg_mano: We are pleased to present the enclosed copies of the above-referenced report.· This report- . summarizes the results of our subsurface exploration and geotechnical engineering study, and offers preliminary recommendations for design and development of the proposed project. We · have enjoyed working with you on 'this study and are confident that the recommendations presented in this report will aid m a successful completion of your project. lf you should have any questions or if we can be. of additional help to you; please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington · Bruce LBlyto~· Principal Engineer BLB/d;i -KED1617A I -Projc:cts\2001617\KE\WP -W:!K I 91 J Fifth Avenue. Suite 100 • Kirkland, WA 98033 • Phone 425 827-770 I • Fax 425 827-S424 ,· SUBSURFACE EXPLORATION AND· PRELIMINARY GEOTECHNICAL ENGINEERING REPORT EVENDELLPRELIMINARYPLAT King County, Washington Prepared for: U.S. Land Development Associates c/o Centurion Development Services 22617 8 .. Drive SE Bothell, Washington 98021 Prepared by: Associated Earth Sciences, Inc. 911 5m Avenue, Suite 100 Kirkland, Washington 98033 425-827-7701 Fax: 425-827-5424 November 16, 2001 Project No. KE0!617A Evendel/ Preliminary Plat King County, Washington Subsurface Exploration and Preliminary Geotechnical Engineering Repon Project and Site Conditions I. PROJECT AND SITE CONDITIONS 1.0 INTRODUCTION This report presents the results of our subsurface exploration and preliminary geotechnical engineering study for the proposed Evendell Preliminary Plat located at the intersection of SE 136111 Street and 160m Avenue SE in King County, Washington (Figure !). The approximate locations of the explorations completed for this study are presented on the Site and Exploration Plan, Figure 2. I. I Purpose and Scope The purpose of this study was to provide subsurface data to be used in the preliminary design and development of the above-mentioned project. Our study included reviewing available geologic literature, excavating exploration pits, and performing geologic studies to assess the type, thickness, distribution, and physical properties of the subsurface soils and shallow ground water conditions. Geotechnical engineering studies were also conducted to determine the type of suitable foundation, allowable bearing pressures, anticipated settlements, floor support recommendations, and drainage considerations. This report summarizes our current fieldwork and offers development recommendations based on our present understanding of the project. 1.2 Authorization Authorization to proceed with this study was granted by Mr. Mike Romano of Centurion Development Services on behalf of U.S. Land Development Associates. Our study was accomplished in general accordance with our scope of work letter dated September 24, 2001. This report has been prepared for the exclusive use of U.S. Land Development Associates and their agents, for specific application to this project. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering and engineering geology practices in effect in this area at the time our report was prepared. No other warranty, express or implied, is made. 2.0 PROJECT AND SITE DESCRJPTION Our understanding of the proposed project is based on our discussions with Centurion Development Services, and on a plan sheet titled Plat of Evendell, dated May 20, 2001. The proposed project would include construction of a new plat. The new plat would include 75 new detached, single-family home sites, a recreation tract, two surface water detention tracts, and an existing area that has been identified as a wetland area that will remain. New paved November 16, 2001 ASSOCIATED EARTH SCIENCES., INC. MAMlda -KE0/617AI -Projt!Cls\100/6/7\KE\WP-W2K Page I Evendell Preliminary Plat King County, Washington Subswface Exploration and Preliminary Geotechnica/ Engineering Repon Project and Site Conditions access roads, buried utilities, and other typical improvements are also planned. At the time this report was prepared, no grading plans were available; however, we assume that most of the project will be built near existing grades, without large excavation cuts or structural fills: . · Preliminary plat plans call for an open detention pond in the south detention tract, and a buried detention vault in the west detention tract. The project site is irregularly shaped, and approximately 12.4 acres in total area. The site is bordered to the north by SE 136<h Street, to the west by I60<h Avenue SE, and to the south and west by existing residential development. Overall vertical relief across the site is on the order of 35 feet, and areas in excess of 15 percent slope are not present, based on topographic information on the previously referenced plan sheet. No surface water was observed on site during our subsurface exploration. At the time of our field study, site vegetation consisted of mature evergreen and deciduous trees, with moderately dense undergrowth, pasture on the west and south parts of the site, and landscaping around the existing house on the north central part of the site. A wetland, mapped by others, was located in the northeast corner of the site. Existing site development included a home with outbuildings on the north central part of the site, a fenced pasture and several outbuildings on th.e west part of the site, and a fenced pasture on the south edge of the site. The existing house on the north central part of the site has an existing septic drainfield southwest of the house. 3.0 SUBSURFACE EXPLORATION Our field study included excavating 12 exploration pits to gain information about the site. The various types of sediments, as well as the depths where characteristics of the sediments changed, are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions changed may represent gradational variations between sediment types in the field. Our explorations were approximately located in the field by measuring from known site features shown on the previously referenced site plan. The conclusions and recommendations presented in this report are based on the 12 exploration pits completed for this study. The number, location, and depth of the explorations were completed within site and budgetary constraints. Because of the nature of exploratory work below ground, extrapolation of subsurface conditions between field explorations is necessary. It should be noted that differing subsurface conditions may sometimes be present due to the random nature of deposition and the alteration of topography by past grading and/or filling. Existing fill should be expected around the existing buildings and drainfield. The nature and extent of any variations between the field explorations may not become fully evident until construction. If variations are observed at that time, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. November 16, 2001 ASSOCIATED EARTH SCIENCES, INC. MAM!da -K£0/6/7AI -Projms\200/6/71K£l\VP-w.?K Page 2 Evendell Preliminary Plat King County, Washington 3 .1 Exploration Pits Subsurface Exploration and Preliminary Geotechnica/ Engineering Repon Projeet and Site Conditions Exploration pits were excavated with a track-mounted backhoe. The pits permitted direct, visual observation of subsurface conditions. Materials encountered in the exploration pits were studied and classified in the field by a geologist from our firm. All exploration pits were backfilled immediately after examination and logging. Selected samples were then transported to our laboratory for further visual classification and testing, as necessary. 4.0 SUBSURFACE CONDITIONS Subsurface conditions on the parcel were inferred from the field explorations accomplished for this study and a visual reconnaissance of the site. As shown on the field logs, the exploration holes generally encountered medium dense grading to very dense, silty sand with gravel interpreted as lodgment till. Topsoil thickness observed in our exploration pits varied from a minimum of approximately 0.5 foot to 1.2 feet. 4.1 Stratigraphy Natural soils observed in our exploration pits consisted of silty sand with gravel, trace cobbles, and trace boulders interpreted as lodgment till. The till was observed to be loose to medium dense at the ground surface, and progressively more dense with increasing depth below the ground surface. The till was typically dense to very dense below approximately 5 feet in depth. The color of the till soils typically graded from brown near the ground surface, to mottled gray at a depth of 2 feet to 5 feet, to gray below approximately 5 feet. Lodgment till was deposited at the base of an active continental glacier, and was compacted by the weight of the overlying glacial ice. Till typically has high strength and low compressibility characteristics, and .is considered suitable for structural support with proper preparation. Till sediments typically contain a significant amount of silt, and are considered moisture sensitive. Moisture sensitive soils are prone to disturbance when wet, and typically perform best in construction applications when dry site and weather conditions prevail. Our interpretations of subsurface conditions are consistent with published information sources, as represented by the Washington State Department of Water Resources Water Supply Bulletin 28, Plate I, Geologic Map of Southwestern King County, Washington. This map indicates that the site is underlain by lodgement till. Although not encountered in our exploration pits, disturbed/fill soil is present, adjacent to the existing structures on the site and around any underground utilities. This non-structural fill is not considered to be suitable for foundation support. November 16, 2001 ASSOCIATED EARTH SCIENCES. INC. MAMlda -KEOJ617rll -Projrcu1200/617\X£1WP -\Al.:?K Page 3 Evende/l Preliminary Plat King County, Washington 4.2 Hydrology Subswface Exploration and Preliminary Geotechnica/ Engineering Report Project and Site Conditions Ground water seepage was encountered in exploration pit EP 0 8 near the interface between weathered till and till sediments. Wet soil conditions were also observed in exploration pit EP- 12 near the interface between weathered till and till sediments at a depth of 8 feet, though no free ground water was observed. The observed ground water conditions are interpreted to represent a perched ground water condition where vertical infiltration of surface water is. impeded by lower permeability soils at depths. Ground water conditions should be expected to vary with changes in season, weather, on-and off-site land usage, and other factors. November 16, 2001 ASSOCIATED EARm SCIENCES. INC. MAM/do. -KE0/617Al -Projws1200/6171KE\WP-W2K Page 4 Evende/1 Preliminnry Plat King County, Washington Subsurface Exploration and Preliminary Geotechnical Engineering Repon Design Recommendations II. DESIGN RECOMMENDATIONS 5.0 INTRODUCTION Our exploration indicates that from a geotechJ;iical standpoint, the parcel is suitable for the proposed development provided the recommendations contained herein are properly followed. The bearing stratum of dense lodgement till is located at approximately 1 foot to 2 feet below existing grades. Conventional spread footing foundations that bear on the medium dense lodgement till may be used for building support. 6.0 EROSION HAZARDS AND MITIGATION To mitigate and reduce the erosion hazard potential and off-site soil transport, we recommend the following: 1) All storm water from impermeable surfaces should be tightlined into approved storm water drainage systems or temporary storage. 2) Silt fences should be placed along the lower elevations of cleared and disturbed areas on the site. · 3) Construction should proceed during the drier periods of the year or temporary erosion and sediment control plans should be developed if construction is to proceed during the winter months. Disturbed areas should be revegetated as soon as possible. 4) Soils that are to be reused around the site should be stored in such a manner as to reduce erosion. Protective measures may include, but are not necessarily limited to, covering with plastic sheeting or the use of hay bales/silt fences. 7.0 SITE PREPARATION Old foundations presently on the site that are under building areas or not part of future plans should be removed. Any buried utilities should be removed or relocated if they are under building areas. The resulting depressions should be backfilled with structural fill as discussed under the Structural Fill section. Site preparation of planned building and road areas should include removal of all trees, brush, debris, and any other deleterious material. Additionally, the upper organic topsoil and any fill . November 16, 2001 ASSOCIATED EARTH SCIENCES, INC. MAM!da -KE016!7,H -Projwsl'XXH6/71K£UVP -\V2K Page 5 Evende/1 Preliminary Plat King County, Washington Subsurface Exploration and Preliminary Geotechnical Engineering Repon Design Recommendations soils, if encountered, should be removed and any remaining roots grubbed. Areas where loose surficial soils exist due to grubbing operations, should be considered as fill to the depth of disturbance and treated as subsequently recommended for structural fill placement. Since the density and moisture content of the soil at the site are variable, random loose or wet pockets may exist, and the depth and extent of stripping can, therefore, be best determined in the field by the geotechnical engineer. Stripping depths are expected to be on the order of 1 foot, but are expected to vary locally. We recommend that building and roadway areas be proof-rolled with a loaded, tandem-axle dump truck to identify any soft spots. Soft areas should be overexcavated and backfilled with structural fill. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, however, we anticipate that temporary, unsupported cut slopes in the till sedim~nts can be planned at a maximum slope of lH: 1 V (Horizontal: Vertical). As is typical with earthwork operations, some sloughing and raveling may occur, and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. 8.0 STRUCTURAL FILL All references to structural fill in this report refer to subgrade preparation, fill type, and placement and compaction of materials as discussed in this section. If a percentage of compaction is specified under another section of this report, the value given in that section should be used. Construction plans are preliminary at this stage and do not include site grading information or building footprint locations. However, placement of structural fill may be necessary in order to achieve the desired site grades in some areas. After overexcavation/stripping has been performed to the satisfaction of the geotechnical engineer, the upper 12 inches of exposed ground in building areas or areas to receive fill should be recompacted to 90 percent of the modified Proctor maximum density using ASTM:D 1557 as the standard. · If the subgrade contains too much moisture, adequate recompaction may be difficult or impossible to obtain and should probably not be attempted before allowing the subgrade to dry/drain adequately. After recompaction of the exposed ground is tested and approved, structural fill may be placed to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the geotechnical engineer, placed in maximum 8-inch loose lifts with each lift being compacted to at least 95 percent of ASTM:D 1557 as the standard. Organic topsoil is not considered suitable for use as structural fill. Lodgement till soils may be used as structural fill if properly November 16, 2001 ASSOCIATED EARTH SCIENCES, INC. .l,UMtdtJ -KE0/6/7,H -Projwsl::!0016/71KEl\VP-W:?K Page 6 Evendell Preliminary Plat King County, Washington Subswface Exploration and Preliminary Geotechnical Engineering Repon Design Recommendations handled and moisture conditioned. In the case of roadway and utility trench filling, the backfill should be placed and compacted in accordance with applicable municipal codes and standards. The top of the compacted fill should extend horizontally outward a minimum distance of 3 feet beyond the location of the perimeter footings or roadway edge before sloping down at an angle of 2H: 1 V. The contractor should note that any proposed fill soils should be evaluated by Associated Earth Sciences, Inc. (AESI) prior to their use in fills. This would require that we have a sample of the material 72 hours in advance of filling activities to perform a Proctor test and determine its field compaction standard. Soils in which the amount of fine-grained material (smaller than the No. 200 sieve) is greater than approximately 5 percent (measured on the minus No. 4 sieve size) should be considered moisture-sensitive. Virtually all of the on-site soils are classified as moisture-sensitive, and were judged to be at or above optimum moisture for compaction. Thus, they should be considered suitable for reuse as structural fill only for dry weather and dry subgrade conditions. In addition, construction equipment traversing the till soils when wet can cause considerable disturbance. If fill is placed during wet weather above the till sub grades or if proper compaction cannot be obtained in these areas, a select import material consisting of a clean, free-draining gravel and/or sand should be used. Free-draining fill consists of non-organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction. A representative from our firm should inspect the stripped subgrade and be present during placement of structural fill to observe the work and perform a representative number of in- place density tests. In this way, the adequacy of the earthwork may be evaluated as filling progresses and any problem areas may be corrected at that time. It is important to understand that taking random compaction tests on a part-time basis will not assure uniformity or acceptable performance of a fill. As such, we are available to· aid the owner in developing a suitable monitoring and testing frequency. 9.0 FOUNDATIONS Spread footings may be used for building support when founded directly on structural fill placed as previously discussed or on medium dense to very dense, lodgement till soils. We recommend that an allowable bearing pressure of 2,000 pounds per square foot (psf) be used for design purposes, including both dead and live loads, for footings placed on till or approved structural· fill placed as discussed above. An increase of one-third may be used for short-term wind or seismic loading. Perimeter footings should be buried at least 18 inches into the surrounding soil for frost protection. All footings must penetrate. to the prescribed bearing stratum, and no footing should be founded in or above organic, non-structural fill, or soft/loose soils. Footings should have a minimum width of 14 inches for I-story structures, with 2 inches of width added for each additional story. November 16, 2001 ASSOCIATED EARTH SCIENCES. INC. MAM!da -KE0/6/7AI -Projws\XJ0/617\KEIWP-w:?K Page 7 Evende/1 Preliminary Plat King County, Washington Subsurface Exploration and Preliminary Georechnical Engineering Repon Design Recommendations The area bound by lines extending downward at lH: 1 V from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM: D 1557. In addition, a 1.5H: 1 V line extending down from any footing must not daylight because sloughing or raveling may eventually undermine the footing. Thus, footings should not be placed near the edge of steps or cuts in the bearing soils. Anticipated settlement of footings founded as described above should be on the order of 1 inch or less. However, disturbed soil not removed from footing excavations prior to footing placement could result in increased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the design bearing capacity of the soils has been attained and that construction conforms to the recommendations contained in this report. Such inspections may be required by the governing municipality. Perimeter footing drains should be provided as discussed under the section on Drainage Considerations. 10.0 FLOOR SUPPORT · A slab-on-grade floor may be constructed directly on structural fill or medium dense, natural ground. Areas of slab subgrade that are disturbed (loosened) during construction should be compacted to a non-yielding condition. Where moisture migration through the floor slab is to be controlled, such as in occupied portions of the house, the floor should be cast atop a capillary break. The capillary break layer should consist of 4 inches of washed pea gravel covered with a polyethylene plastic vapor barrier. Based on American Concrete Institute recommendations, we also suggest placing a 2-to 3-inch layer of clean sand over the vapor barrier to protect the vapor barrier and to allow some moisture loss through the bottom of the slab to aid in the curing process. Sand should be used to aid in the fine-grading process of the subgrade to provide uniform support under the slabs. 11.0 DRAINAGE CON SID ERA TIO NS Traffic across the site soils when they are moist or wet will result in disturbance of the otherwise firm stratum. Therefore, prior to site work and construction, the contractor should be prepared to provide drainage and subgrade protection, as necessary. All perimeter footing walls should be provided with a drain at the footing elevation. Drains should consist of rigid, perforated, PVC pipe surrounded by washed pea gravel. The level of the perforations 1n the pipe should be set approximately 2 inches below· the bottom of the footing. The drains should be constructed with sufficient gradient to allow gravity discharge away from the building. Roof and surface runoff should not discharge into the footing drain system but should be handled by a separate, rigid tightline drain. In planning, exterior grades November 16, 2001 ASSOCIATED EARTH SCIENCES, INC. MAM!da -KE0/617,H -Projwsl20016/7\K£!WP-\V:!K Page 8 Evende/1 Preliminary Plat King County, Washington Subswface Exploration and Preliminary Geotechnical Engineering Repon Design Recommendations adjacent to walls should be sloped downward away from the structure to achieve surface drainage. 12.0 PROJECT DESIGN AND CONSTRUCTION MONITORING At the time of this report, site grading, structural plans, and construction methods have not been finalized. We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. We recommend that AESI perform a geotechnical review of the plans prior to final design completion. In this way, our earthwork and foundation recommendations may be properly interpreted and implemented in the design. We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundation depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. Construction monitoring services are not part of this current scope of work.· If these services are desired, please let us know and we will prepare a proposal. We have enjoyed working with you on this study and are confident that these recommendations will aid in the successful completion of your project. If you should have any questions, or require further assistance, please do not hesitate to call. Sincerely, ASSOCIATED EARTH SCIENCES, INC. Kirkland, Washington Melissa A. Magirnson, P.E. Senior Staff Engineer Attachments: Figure I: Figure 2: Appendix: November 16, 2001 Vicinity Map Site and Exploration Plan Exploration Logs MAM!da -K£0/617AI -Projects\'2001617\KEI\VP-......-.:?K Bruce L. Blyton, P.E. Principal Engineer ASSOCIATED EARTH SCIENCES, INC. Page 9 ~ E .f ~ ;; ij Associated Earth Sciences, Inc. ~ l~ ;; ~ ~ ~ ~ 11 / ~000 FUl O 000"' Printed lkiM TOPOI Cl99S Wikilbw11 P:ocii.x:tions (ITinl'.topo.com) VICINITY MAP , EVENDELL PRELIMINARY PLAT KING COUNTY, WASHINGTON FIGURE 1 DATE 11/01 PRDJ. NO. KE01617A 0----------------------------------------------------------------- "'o o'> <o' o'> '~:;; 2 R-4 90' "'" o'> :-,j ~ S>-10; 1Q' " ,µ·· 90' ;~ ~ :· i 4 ~, ~ ~l' II) EP-1211\' ... -v rfTIMPI )Nil .s,'W~>a;l\.l1-"1)~111L) --~ -~·4'1.11 kll bCl. '~ ~m'«ll•Jo..ZIJr;r ,_W'Q.•2D.lDIJCSj&.1J'~ ]!Q'._ 5· ~ 103' '~ • {~ 90' 8 90• 7 -90• 6 -lOJ' "'o o'> " 9 .,. ..., !2'b6P·11' 99' 11 JO,' ll ;,, • • ,. ~ ~ R-4 -- ,,,--' x,,,,,,,,, ~,,,,,,,, ''-'-' '"""'"' 48 0 eo~ I 87' 48 ,,· . .,. ... 47 ~ 51 f:. 132··.. ~ --1' .,. I Jo,' I 46 ~ ~!~~ R2' 413 .,. \ •' o' @ I ,. ,( 44_ J l:e 42 :el 41 l!., 8 " "'l,n -,• ~· R-4 @\ @ ,. G 12 ~ _,,._ 13 ' 0 • • @\~ .,. 14 ~ ,,. ~ 15 I M" ,. ,• 111 i:; / r. !l8 • 76° 74 ,,. 8 . • 69' . --~ -57 0 45· 45• ~ 72 95' • 85' -! ----ll .2.0· 0 ,. 31 ~ ~· I 20· }.~ 70:e~ !l8 \lJ 59~ 71 ~ ~ -.., PRIVATE ACC(SS IS, i<" TR,i,CT T ·~ , .. N' ... 9· r· -"~"',,,,i\T_,,,,._'_EP., · ~..,-fll EP-4 i::::tf"ca,T. US£ ORM:W"l ' 4_9_" ,,. 20 ~ 11V,CT ")l' / 88 ~ ea ~l'".i. 81 ·~1 80 ~ 151 ~-.2_4' ~ IJ:' 27 ~I 28 !i 11.Q.' 205' R(CREATIOM i'AACT 'K' 14,868 SF ' ' = t G2~gt.1~ i'~ 17 8fi' ~----! 1 ·, M' 20s· @ ® 10 79 • 83 'g 84 9 I 11: 1S ~-·J c 79' 1-' 00~ I I~ ..; --,-.. . J '° ! ~....,I.....,.,.'' -,--.,.,.., -:. ~~~==-~ e6 ;I, 1!111 :. J J ; \ \ \[]( f ~ OCT / ~\c\\ !,, S,' ! ~, w / , :~ EP,.3\j' ..:'> I (\\\1 . ,:1/gl N A ~ IJO ,,. Fm ~.-.... ... : c..-o..*'P'N .. ~ Associated Earth Sciences, Inc. ~m~[!i~ [O I : I j i~ 19 ° 20 !J 2.1 -~ 2.2 gt 23 'al ~" i I I I I I r:,u , ! I I I ' Cl \ !:O' I so· i ~o· ~o· . 50· J e,O .,c G; '-' .,-~ =I 2.6 ;: 'l l c¢l i ~ 24 ~1 25 ", ' -, . . i •o ! ';j --· ··:_;, . I 50 ~-.. ,.o ~o -rc:11:::0~~ =~-:! ·~gf7,: ::,o,<'O,J =~-~--·~~; .. s~, ~ ~ ";'-"°;~~= 7 .......... SITE AND EXPLORATION PLAN EVENDELL PRELIMINARY PLAT KING COUNTY, WASHINGTON <h" d" .,., o"' .,o o' sP o"' "" <>"' "'" c:? "'" o"' R-4 LEGEND EP-1 IE] Approxima1 e location of exploration pit FIGURE 2 DATE 11/01 PROJECT NO. KE01617A .j '. i " > " u.i 0 0 "' ci z C o. "' " C s " a: ~ 0 "' C .. ,5 e 0 ::; .. 'a Cl] "' " .s e '!! .. e 8 C 0 = u e IL C: 0 'ii it .. "l! .. CD Well-graded gravel and GW gravel with sand, little to no fines GP Poorly-graded gravel and gravel with sand, little to no fines Silty gravel and silty GM gravel with sand Clayey gravel and GC clayey gravel with sand Well-graded sand and :Ni sand with gravel, little to no fines SM SC Poorly-graded sand and sand with gravel, little to no fines Silty sand and silty sand with gravel Clayey sand and clayey sand with gravel Sil~ sandy silt, gravelly silt, ML silt with sand or gravel CL Clay of low to medium plasticity; silty, sandy, or gravelly clay, lean clay Organic clay or silt of low OL plasticity ·.-· ···-= .. ·:··.···.:· ,. _):/-r:r~;;:i· Tenns Describing Relative Density and Consistency Co=a- Grained Soils F'111&- Grained Soils Density SPT"\,1ows1root Ve,y Loose O to 4 loose 4 ID 10 Medlum Dense 10 ID 30 Dense 30 to so Ve,y Dense >50 Consistency SP"r2'blowsifuot Ve,y Soft O ID 2 Soft 2 to 4 Med"11J1T1 Stiff 4 to 8 Stiff 8 to 15 Ve,y Stiff 15 to 30 Hard >30 Component Definitions Test Symbols G = Grain Size M = Moisture Cootent A = Atterberg Limits C = Chemical DD = Diy Del);lity K = Permeability Desaiptive Term Size Range and Sieve Number Bouldem Larger than 12' Cobbles 3" to 12' Gravel 3" to No. 4 (4.75 rm,) Coarse Gravel 3' to 'J/4' Fine Gravel 'J/4' lo No. 4 (4.75 mm) Sand No. 4 (4.75 rm,) to No. 200 (0.075 mm) Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) Silt and Clay Smaller than No. 200 (0.075 mm) (Jl Estimated Percentage Moisture Content Component Percentage by Diy • Absence of moisture, Weight dusty, dry to lhe touch Trnce Fe,v Little Wrth -Sampler Type <S Sightly Moist -Perceptible 5 to 1 O moisture 15 to 25 Moist· Damp but no visible • Non-prinaiy coarse water constltllents: ~ 15% Ve,y Moist -Waler visible but -Fines content between not free draining 5%and15% Blows/6' or portbn of 6' Wet-Visible free water, usually from belcw water table Symbols Bastic silt, clayey silt. silt 2.0" 00 with micaceous or I • • Sampler Type Oesaiption eemome -Fiae,padcwih Splij-Spoon dialomaceous fine sand or Sampler lliWJr---t"s"'ilt~-:-:-:-.-:--:--.-:-.-:--1 (SP1) Clay of high plasticity, sandy or gravelly clay. fat Bulk sample MH c!ay with sand or gravel • 3.0' 00 Splft-Spoon Sampler 325' OD Spla-Spoon Ring Sampler • JD' OD Thin-Wall Tube Sampler (mduding Shelby tube) Pornon not recovered ,., blank casirg sedlon Sa....-..l casirg orHyaotlp --pad< End cap Organic clay or silt of medium to high plastic:ty 111 Percentage by dry weigh< C2l (SFT] Slal1dan:I Penelralion Test i"J Depth cf grcunC'Nater crl;,---+--------1 (ASTM D-1586) ,-. .!l Peat, muck and other (3) 1n General Acccrdaflca with 8" :Ci~ :'l Am = Al time of dnlling 'fl_ --Slalic waler level (dale) 151 Combined uses symbols used ror lines between 5% and 15% ~ _g, e.:l highly organic soils Standard Practice lcr Desoiption j :c O and ldef11ific:al!on cl Soils (ASTM D-2488) ;;'-----==:=__ _ _L _________ _L ____________________________ __, ;ii: ~ns of .soil.s in :his report are b~ed on V$1.d fi&kl md/Ot laboratory obseC'vations. \IIOich indude density/consistency, moi:stun, o:n:filion, grain size, d plasticity e::stfmat.e.s and should not be co~ed to imply fl'*I or laboratory te:stfng unless p~nt&d heretl'T. 1./buah'nanual and/or laboratory ~as:sn'!catk>n .othcds ot ASTM G-2487 and D-24.88 ware~ ill an idemtl'lcadon guide ror the Un.iffcd Soil ~rlkatlon s~ E i======================================= i i 1c111~:~IATEO !H~ ' SCIENCES, INC FlQJRE Exploration Log Key A-1 :a-----------------------------------------'--------- 1 - 2 - 3 - 4 - 5 - 6 - 7 - __ LOG OF EXPLORATION PIT NO. EP-1 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for U,e named project and should be read lqgelher with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplflcatlon of actual conditions encountered. DESCRIPTION Topsoil and Grass Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine SAND, little fine gravel. (SM) . TIii Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, some fine to coarse gravel, trace cobbles. (SM) Becomes very dense and less mottled. (SM) 8-1------------------------------------ 9 - B~ttom of exploration pit at depth 8 feet No ground water seepage or caving. Elevation 467'. 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - g ~-------------------------------------------.; ~ j ;;: ~ ;;; 0 ~ ~ u Logged by: BWG Approved by: Evendell Preliminary Plat King County, WA ASSOCIATED EARTH SCIENCES, INC Project No, KE01617A November 2001 ~------------------------------------------- g £ Q. .. 0 1 - 2 _ LOG OF EXPLORATION PIT NO. EP-2 This log Is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgeUier with that report for complete interpretation. This summary applies onty to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplflcatfon of actual condiUons encountered. DESCRIPTION Topsoil and Forest Duff Weathered TIii Loose to medium dense, moist, reddish brown, SIL TY fine to medium SAND, little fine gravel. (SM) Till Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, some fine to coarse 3 -gravel, trace cobbles. (SM) 4 - 5 -Becomes very dense and less mottled. (SM) 6 - 7 - 8 - 9-1--------------------------------- 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 9 feet No ground water. seepage or caving. Elevation 465'. ~-----------------------------------~-------:! I • Ji ii'. C> "' w :; f Logged by: BWG Approved by: !.! ___________ -'-----------------~· Project No, KE01617A November 2001 LOG OF EXPLORATION PIT NO. EP-3 This Jog is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgether with that report for complete Interpretation. This summary applles only to the location of this trench at the time of excavation. Subsurface condifions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 -Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine SAND, trace fine gravel. (SM) 2 - TIii 3 -Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, some fine to coarse 4 - 5 - 6 - 7 - 8 - 9 - 10 11 12 - 13 - 15 .. 16 - 17 - 18 - 19 - gravel, few cobbles. (SM) Grades to moist to wet (no free water) to bottom of exploration pit. Grades to very dense and less mottled. (SM) Bottom of exploration pit at depth 14 feet No ground water seepage or caving. Elevation 458'. ~-------------------------------------------,; -Evendell Preliminary Plat j King County, WA ~ <.1 &S1"7 ASSOCBATEC ~ Logged by: BWG I" .<t!l!)ill!!l. EARTIHI 0 Approved by: Mmi!i:C SCIENCES, INC ~---------------------------- Project No. KE01617A November 2001 · g 5 Q. " 0 LOG OF EXPLORATION PIT NO: EP-4 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete Interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 -~---------------=--cc--,-=~---------------Weathered TIii 2 -Loose to medium dense, moist, reddish brown, SIL TY fine SAND, little fine gravel. (SM) 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - TIii Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, little to some fine gravel. (SM) Very dense, damp, gray, SILTY fine SAND, little fine gravel. (SM) Bottom of exploraUon pit at depth 1 O feet No ground water seepage or caving. Elevation 464 ', 1::-------------------------------------------ri n ~ ~ Logged by: BWG Approved by: !;! ____________________ _ Project No, KE01617A November 2001 1 2 - 3 __ LOG OF EXPLORATION PIT NO. EP-5 This log is part of the report prepared by Associated Earth Sciences, Inc. {AES!) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. · DESCRIPTION Topsoil and Forest Duff Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine SAND, little fine gravel. (SM) Till Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, some fine gravel. (SM) 4 - 5 - 6 - 7 - 8 - g 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Becomes very dense and gray. (SM) Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 468'. ~---------------------------------------- ii I ~ !: ~ 0 ~ ~ Logged by: BWG Approved by: Evendell Preliminary Plat King County, WA &SIASSCJCIATEC r~ . EARTH ._,~ SCIENCES, INC Project No, KE01617A November 2001 ~------------------------------------------- g g £ C. " 0 LOG OF EXPLORATION PIT NO. EP-6 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgettier with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simplficatlon of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 -Weathered TIii Loose to medium dense, damp, reddish brown, SIL TY fine SAND, little fine gravel. (SM) 2 - 3 -1-----------------T=m---------------- Medium dense to dense, damp, mottled gray, SIL TY fine SAND, little fine gravel, trace cobbles, 4 -trace boulders. (SM) 5 -Becomes very dense and gray. (SM) 6 - 7 - 8 - 9-1-------------------------------------''- 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 474'. N----------------------------------------------M ' l a: ;! w 0 M ~ ~ Logged by: BWG Approved by: Evendell Preliminary Plat King County, WA &SI~ ASSOCIATED V' K,Jl!!A EARTH ~ SCIENCES, INC Project No, KE01617A November 2001 s! _________________________________________ _ g 5 C. w 0 LOG OF EXPLORATION PIT NO. EP-7 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgelher with that report for complete Interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location WIU1 the passage of Urne. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 -1------------------,-,,,....-,,.-~=~-------------Weathered Till 2 _ Loose to medium dense, damp, reddish brown, SIL TY fine SAND, some fine gravel. (SM) Till 3 -Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND, little to some fine to 4 - coarse gravel, trace cobbles. (SM) 5 - Becomes very dense and gray. (SM) 6 - 7 - 8 - 9 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 473'. ~-------------------------------------------,.; i z o'. ;! ;;; 0 le ~ Logged by: BWG Approved by: Project No. KE01617A November 2001 !;! ____________________________________ _..;. _____ _ LOG OF EXPLORATION PIT NO. EP-8 g This log is part of lhe report ,l'repared by Associated Earth Sciences, Inc. (AESI) for lhe named e,roject and should be 5 read together with that repq for comlllete interpretation. This summary ~plies only to the loca ·on of this trench at the a. ·ume of excavation. Subsurface condl ·ens may change at this location wi llle passage of time. The data presented are " Cl a simplfication of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 Weathered Till 2 -Loose to medium dense. moist, reddish brown, SIL TY fine to medium SAND, little fine gravel. (SM) 3 Till 4 -Medium dense to dense, wet, mottled gray, SIL TY fine to coarse SAND, little to some fine gravel, trace cobbles. (SM) 5 - 6 -Becomes very dense and gray. (SM) 7 - 8 - 9 10 -Bottom of exploration pit at depth 9 feet Weak ground water seepage from 3'-6 developed after 1/2 hour. No caving. Elevation 476'. 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - . 19 - ~---------------------------------------------,.; ~ ~ ;. 0 :;' Logged by: BWG Approved by: Project No. KE01617A November 2001 ~--------------------------------------------- g = a. ~ D LOG OF EXPLORATION PIT NO. EP-9 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read together with that report for complete interpretation. This summary applies only to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a simpllicatlon of actual conditions encountered. DESCRIPTION Topsoil and Forest Duff 1 Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine to medium SAND, trace fine gravel. 2 -(SM) TIii 3 -Medium dense to dense, damp, mottled gray, SIL TY fine to coarse SAND with fine to coarse gravel, 4 -trace cobbles. (SM) 5 -Grades to very dense and gray. (SM) 6 - 7 - 8 - 9-t-------------------------------- 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 482'. . ~---------------------------------------------- " ? • £ ~ ~ :: ;; ;; ii'. ~ Logged by: BWG Approved by: Project No. KE01617A November 2001 ------------------------------------ g 5 C. ~ 1 - __ LOG OF EXPLORATION PIT NO. EP-10 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI} for the named project and should be read togeUier with that report for complete interpretation. This summary applles only to the locafion of this trench at lhe Ume of excavation. Subsurface condiUons may change at this location with the passage of time. The data presented are a simplfication of actual conditions encountered. DESCRIPTION Topsoil and Grass Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine to medium SAND, little fine to coarse 2 _ gravel. (SM) 3 - 4 - 5 - 6 - 7 - 8 - 9 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Till Medium dense to dense, moist, mottled gray, SIL TY fine to coarse SAND, some fine to coarse gravel. (SM) Becomes very dense and gray. (SM) Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 492'. ~--------------------------------------------- :; Evendell Preliminary Plat I j King County, WA ii'. :: ASSCCBATEC Project No, KE01617A ;;; Logged by: BWG , EARTH 0 Approved by: SCIENCES, INC November 2001 ~--------------------------------------------- __ LOG OF EXPLORATION PIT NO. EP-11 This log is part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgetJier with that report for complete interpretation. This summary applies only to the locafion of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of Ume. The data presented are a slmplfication of actual condiUons encountered. . DESCRIPTION Topsoil and Grass Weathered TIii 1 -Loose to medium dense, damp, reddish brown, SIL TY fine SAND, little fine to coarse gravel. (SM) 2 - 3 Till Medium dense to dense, moist, mottled gray, SIL TY fine to coarse SAND with fine to coarse gravel, 4 -trace cobbles. (SM) 5 - Grades to very dense and gray. (SM) 6 - 7 - 8 - 9 -4--------------------------------------1 10 11 - 12 - 13 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 9 feet No ground water seepage or caving. Elevation 488'. ~------------------------------------------- I ;: ;! m 0 2 Logged by: BWG Approved by: Evendell Preliminary Plat King County, WA ASSOCIATED EARTIHI SCIENCES, INC Project No. KE01617 A November 2001 ~------------------------------------------- g 5 g. 0 1 - 2 - 3 - 4 - 5 - _ LOG OF EXPLORATION PIT NO. EP-12 This log ls part of the report prepared by Associated Earth Sciences, Inc. (AESI) for the named project and should be read tqgettier with that report for complete interpretation. This summary applies onty to the location of this trench at the time of excavation. Subsurface conditions may change at this location with the passage of time. The data presented are a slmplfication of actual condiUons encountered. DESCRIPTION Topsoil Weathered Till Loose to medium dense, damp, reddish brown, SIL TY fine to medium SAND, few fine gravel. (SM) Till Medium dense to dense, moist to wet, mottled gray, SIL TY fine to coarse SAND, some fine to coarse gravel, trace cobbles. (SM) Becomes very dense, wet, and gray. (SM) 6 - 7 - 8 - 9 - 10 - 11 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - Bottom of exploration pit at depth 11 feet No ground water seepage or caving. Elevation 484'. i--------------------------------------,.; ~ ~ ;;; 0 M ~ Logged by: BWG Approved by: Project No. KE01617A November 2001 g __________________________________________ _ ,, 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES October 28, 2002 Centurion Development Services 22617·-8111 Drive SE . Bothell, Washington 98021 RE: ADDENDUM to the Wetland Evaluation and Delineation Report, Wildlife Habitat Evaluation, and Conceptual Wetland Mitigation Plan for the Evendell . Project Site Dear Mr. Romano, PAGE 02 Subsequent to the preparation of the "Wetland Evaluation and Delineation Report, Wildlife Habitat Evaluation, and Conceptual Wetland Mdigation Plan' for the Evendell Project Site, (Habitat Technologies, May 2001) the Selected Action Plan has been modified. This addendum describes U,e changes from the original report. The Evendell Project Site is approximately 14 acres in total size and is located east of the City of Renton, King County, Washington. Onsite assessment of the project site following the procedures outlined in the Washfngton State Welfands Identification and Delineation Manual (Wast,. Manual) and the Corps of Engineers Wetlands Delineation Manual (1987 Manual) resulted. in the identification of one area (Wetland A) that exhibited hydric soils, wetland hydrology, and hydrophytic vegetation consistent with the established criteria of both the Wash. and 1987 Manuals. The preliminary Selected Action Plan of the l:vendell project site included the creation of independent lots suitable for the development of single-family homesites consistent with the King County Comprehensive Plan. Buffer averaging was to be used along the western boundary of the onsite wetland as a part of this lot creation. Selected Actfion Plan The Selected Action Plan of the E,vendell project site focuses on the creation of independent lots suitable for the development of single-family homesites consistent with the King County Comprehensive Plan (Attachment 1 - Preliminary Plat}. An essential element of this process is the development of access roadways and utillty corridors that meet both King County health and safety standards and the goal of avoidancs and minimization of potential short- term or Jong-term adverse impacts to aquatic environments. wetlands, stnlams, flsherios, vrildllfe -mitigation and pc;,rmittlng solutions , P.O. Box 1088, P11yalliap, Washington 98371 , voice 253•845-5'119 fan 253~1-1942 Evendetl-1 00082 Wetlendl'lifddl'ifa Report ADDENOUM 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 03 A primary feature in the creation of these homesite lots will be the establishment of a protective buffer adjacent to the identified onsite wetland consistent with King County Sensitive Area codes. The creation of these homesite lots will not require placement of fill within identified wetland areas or reduction of the standard buffer width as previously proposed. Site development requires construction of road improvements within existing unopened SE 138 111 Street right-of-way along the northern project boundary. This will require the unavoidable filling of the northem 200 square feet of Wetland A and reduction of the associat,d buffer by 4,649 square feet. In addition, in response to King County staff concems, the applicant has proposed constructing road frontage improvements along 1601h Avenue SE consisting of a paved shoulder and relocation of the drainage ditch. This will require the unavoidable intrusion into 2,340 square feet of the buffer for Wetland A. As mitigation for the unavoidable loss of wetland and buffer associated with required . road improvements, the wetland_buffer will be increased by the addition of 15,495 square feet of forested_area located in the northeast comer of the site between the eastern boundary of the wetland and 16ott' Ave. SE. Provision of this additional buffer fully compensates for the unavoidable · intrusions into the wetland and standard buffer areas and will not adversely impact the remaining wetland area. ELEMENTS OF THE BUFFER ADDITION AND WETLAND RESTORATION PLAN 1. The buffers associated with the identified onsite wetland will be established to the King County standard 50-foot width. Identified onsite wetland and associated buffers will run be adversely impacted by future onsite land uses. 2. As a part of the development of the required roadway improvements the actual encroachment into buffer area of Wetland A will be held to the minimum necessary to meet County roadway requirements. Following placement of the roadway improvements the roadway side slopes within the buffer areas will be revegetated by seeding with an appropriate seed mixture. 3. As compensation for unavoidable encroachment into the north end of Wetland A, 400 square feet (a 2 to 1 ratio} of degraded wetland in the proximity of the edge of the roadbed will be enhanced through the planting of native trees and shrubs. This restoration will enhance wetland function by providing structural diversity in the plant community. 4. As compensation for unavoidable encroachment into the north end of the buffer associated with Wetland A and a portion of the buffer on the east side of Wetland A the standard buffer will be inaeased to encompass the entire northeast comer of the property. This buffer width increase will enhance Evendell -2 OOD62 WellandM/ildlife Report ADDENDUM • I -. 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 04 ~· wetland function relative to that provided by standard buffers through increased visual and auditory blockage from 1601h Ave. SE and greater conservation of wildlife habitat opportunities . !!ii. In order to protect the wetland and associated buffer erosion control Best Management Practices will be implemented during all phases of construction. These measures include silt fencing along the buffer prior to any onsite actions. In addition, all exposed areas will be seeded with low growing grasses upon the completion of onsite actions. 6. All activities related to the establishment of the buffer areas will be .. monitored by the project'biologist. WETLAND RESTORATION AND BUFFER ENLARGEMENT PLAN The GOAL of the identified buffer addition plan is to ensure that proposed site development actions (i.e. the upgrading of an existing right-of-way roadway to meet King County health and safety standards) do not create a short-term or long-term adverse impact to the onsite wetlands or associated buffer areas. The total amount of King County jurisdictional wetland area to be unavoidably modified by this project equals 200 square feet. As compensation · for this unavoidable impact to Wetland A, 400 square feet (a 2:1 ratio) of remaining degraded wetland will be restored through the planting of native trees and shrubs. The total amount of King County jurisdictional buffer area to be unavoidably modified by this project equals 6,986 square feet. As compensation for this unavoidable impact to Wetland A, 15,495 square feet (a 2.2:1 ratio) of area at the northeastem comer of the project will be dedicated to buffer area. The purpose of the Wetland Restoration Plan is two fold. Finrt, to define the wetland restoration plan proposed as an element of the construction of the Evendell development. Second, to identify the objectives and Cl'ileria whereby the success of the completed wetland and buffer restoration plan will be determined. EvandeJI • 3 00082 W'!llandlWlldlifB Report ADDENDUM 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 05 ·"'·-· WETLAND IEVAlUATION AND IDEllN!EATION REPORT, WillDlilFE HABITAT EVALUATION, AND COMPIENSATOR:Y WETLAND MITIGATION Pl.AN EVENDELL RESIDENTIAL COMMUNITY King County, Washington Part of Section 14, Township 23 North, Range 5 East, W.M. prepared for Centurion Development Services 22617 -81h Drive SE Bothell, Washington 98021 prepared by HAB.ITAT TECHNOLOGIES · P .0. Boit 1088 Puyallup, Washington 98371-1088 253-845-5119 May 15, 2001 wetlands, streams, fisheries, WIidiife -mitigation and permitting solutions P.O. Box 1088, Puyallup, W38hington 98371 voice 253•845•5.119 fax 253-841-1942 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 06 EXECUTIVE SUMMARY The Evendell Residential Community is approximately 14 acres in total size and located to the east of the City of Renton, King County, Washington. The project site is comprised of two adjacent parcels; Parcel A of 11.5 acres, and Parcel B of 2.5 acres directly to the west of Parcel A. The Parcel A portion of the project site is dominated by a mature Douglas fir (Pseudotsuga menziesi1) forest plant community on the periphery of the parcel that has been planted following prior forest harvest activities. A single- family dwelling is located in the northern portion of Parcel A The center of Parcel A has been cleared and is dominated by a dense canopy of Himalayan blackberries (Rubus procera). The southern portion of Parcel A is dominated by active livestock pasture. Parcel B portion is dominated by an active livestock pasture which also contains a single-family dwelling and four associated buildings. Onsite assessment of the project site following the procedures outlined in the Washington State Wetlands Identification and Delineation Manual (Wash. Manual) and the Corps of Engineers Wetlands Delineation Manual (1987 Manual) resulted in the identification of one area that exhibited hydric soils, wetland hydrology, and hydrophytic vegetation consistent with the established criteria of both the Wash. and 1987 Manuals. This area had been impacted by prior forest harvest activities and grading and was dominated by a mixture of deciduous trees and shrubs. This assessment, completed in accordance with King County regulations, included an evaluation of the function and value rating for the identified wetland, a classification of the wetland following the U.S. Fish and Wildlife methods, and an identification of the standard King County buffer width required for this ·wetland. Onsite assessment also included an evaluation of the wildlife habitat availability and utilization. Species presence and habitat utilization were evaluated following the methods identified by Horner and Raedeke (1989) and within U.S. Fish and Wildlife Service Publication 80/58 (Mikol, 1980). In addition, the King County Wildlife Study Guidelines (Draft Wildlife Management in King County, Issue Paper, 1993) were followed to assure consistency with the King County permit process and documentation of habitat types. WETLAND SIZE ONSITE CLASSIFICATION KING COUNTY FUNCTION STANDARD (square feet) (USFWS) RATING AND VALUE BUFFER RATING WIDTH A 17,162 PFOE, PEME 2 low 50 feet PFOE palustnne, forested, seasonally flooded/saturated PEME palustrlne, emergent, seasonally flooded The "habitat type" best represented within the site would be that of •young conifer upland forest -low understory." This habitat type included three isolated freshwater wetlands and a mixed freshwater wetland drainage corridor. • 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 07 ··-·· PRIMARY HABITAT TYPES INCLUDED MINOR HABITAT TYPES Conifer Upland Forest Deciduous Forested wetland . low understorv Aaricultural Lands Persistent Lowland Shrub The U.S. Army Corps of Engineers and King County, as well as a number of other local, state, and federal agencies, regulate activities in and around identified wetland and drainage corridor areas. Such regulations focus on the avoidance of adverse impacts to wetlands, streams, associated buffers and the mitigation of such impacts that cannot be avoided. King County has established criteria to categorize wetlands for purposes of regulation and the establishment of buffers. In addition, King County allows a limited amount of alterations to wetlands (i.e. isolated wetlands, roadway crossings) provided such impacts are mitigated pursuant to an approved mitigation plan. The Selected Action Plan of the Evendell project site focuses on the creation of independent lots suitable for the development of single-family homesites consistent with the King County Comprehensive Plan. Buffer averaging will be used along the western boundary of the onsite King County Class 2 Wetland (I.e. Wetland A) as a part of this lot creation. Such averaging will provide additional protection to wetlands and enhance the wetland's functions. In addition, improvements to the existing right-of-way (South 136th Street -a primary collector route for the area) which fronts the project along its northern boundary will require the unavoidable filling of the northern 200 square feet of Wetland A and the reduction of the buffer associated with this area of the wetland. Through restoration of the existing onsite wetland, addition of buffer area along the eastern side of Wetland A, and onsite erosion protections this unavoidable wetland intrusion will be fully compensated, will enhance onsite wildlife habitats, and will not adversely impact the remaining wetland area. The GOAL of the wetland mitigation and buffer averaging plan is to ensure that proposed site development actions (I.e. the improvement of an existing right-of-way to meet King County health and safety standards) do not create a sh.art-term or long-term adverse impact to the onsite wetland or associated buffer areas. 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 08 TABLE OF CONTENTS INTRODUCTION ..................... u., ............... ,n,, ....................................... ,n,uouoo•••••••;··· .... 1 STUDY PURPOSE .................................................................................................... · 1 SITE DESCRIPTION ................................................................................................... 1 BACKGROUND INF.ORMATION ...•....... ; ........................................................................ 2 NATIONAL WETLAND INVENTORY MAPPING ......................................................... 2 STATE OF WASHINGTON PRIORITY HABITATS AND SPECIES ............................ 2 STATE OF WASHINGTON STREAM CATALOG ....................................................... 2 KING COUNTY SENSITIVE AREAS MAPPING ......................................................... 2 SOILS MAPPING ........................................................................................................ 2 AERIAL PHOTO ANALYSIS ....................................................................................... 3 ONSITE EVALUATION -WETLANDS ........................................................................... 3 WETLAND STUDY METHODS ................................................................................... 3 FIELD OBSERVATION ............................................................................................... 4 '.J Vegetation ..................................................................................... : ................. 4 c. Soils ................................................................................................................ 5 Ci Hydrology ........................................................................................................ 5 WETLAND AND STREAM DETERMINATION ............................................................... 6 WETLAND FUNCTION AND VALUE ASSESSMENT .................................................... 6 ONSITE WETLAND VALUATION ............................................................................... 8 ONSITE EVALUATION -WILDLIFE .............................................................................. 9 WILDLIFE STUDY METHODS .................................................................................. 9 ONSITE HABITAT TYPES ........................................................................ , .............. 10 PLANT AND ANIMAL SPECIES OBSERVATIONS .................................................. 10 MOVEMENT CORRIDORS ...................................................................................... 12 PRIORITY SPECIES ................................................................................................. 12 STATE CANDIDATE SPECIES ................................................................................ 12 REGULATORY CONSIDERATION .............................................................................. 12 U.S. ARMY CORPS OF ENGINEERS· SECTION 404 ............................................... 13 KING COUNTY -"ENVIRONMENTALLY SENSITIVE AREAS" ORDINANCE 21A.24 ............. 13 D Wetland and Stream Classes ........................................................................ 13 o Wetland/Stream Alteration ............................................................................. 14 D Roadway Improvements ................................................................................ 14 o Required Buffers ........................................................................................... 15 SELECTED ACTION PLAN ................................ ., ....................................................... 15 ELEMENTS OF THE COMPENSATORY MITIGATION PLAN ..................................... 16 DESCRIPTION OF THE COMPENSATORY MITIGATION PROGRAM .................... 17 GOAL AND OBJECTIVE OF THE MITIGATION PLAN ............................................. 18 PERFORMANCE CRITERIA ..................................................................................... 18 MITIGATION REPLACEMENT/ENHANCEMENT ..................................................... 19 SUMMARY TABLE OF WETLAND FUNCTIONAL BENEFITS ................................. 20 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 09 SELECTED PLANT COMMUNITIES ........................................................................ 20 CONSTRUCTION INSPECTION ............................................................................... 21 WATER QUALITY PROTECTIONS DURING CONSTRUCTION ............................. 22 CONSTRUCTION SEQUENCE ................................................................................ 22 PROJECT MONITORING ......................................................................................... 22 STANDARDS OF SUCCESS .................................................................................... 23 Vegetation Sampling Methodology and Monitoring Schedule ................................ 23 Vegetation Monitoring ........................................................................................... 23 Vegetation Monitoring Sequencing ............................. : .......................................... 24 .WILDLIFE OBSERVATIONS .................................................................................... 25 VEGETATION MAINTENANCE PLAN ...................................................................... 25 CONTINGENCY PLAN ............................................................................................. 26 PLANTING NOTES ....................................................................... , ........................... 26 FINANCIAL GUARANTEE ........................................................................................ 26 FIGURESREFERENCE LIST ..................................... ; ................................................. 27 REFERENCE LIST ....................................... : ............................................................. ,. 28 APPENDIX A .... ; ........................................................................................................... 29 APPENDIX 8 .................................................................................................................... 30 • 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 10 STANDARD OF CARE. Prior to extensive site planning, this document should be reviewed and the wetland boundaries verified by the appropriate resource and permitting agencies. Wetland boundaries, wetland classifications, wetland ratings, and all proposed wetland restoration and enhancement activities should· be reviewed and approved by King County and potentially other regulatory staff. The above consultants have provided professional services that are in accordance with the degree of care and skill generally accepted in the nature of the work accomplished. No other warranties are expressed or implied.· The consultant is not responsible for design costs incurred before this document is approved by the appropriate resource and permitting agencies. Mark Heckert Senior Wetla.nd Ecologist ' 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 11 INTRODUCTION This report details the culmination of activities and onsite evaluations undertaken to complete both a wetlands evaluation and a wildlife habitats assessment as an element of the planning and site development of the Evendell Project Site. The project area is approximately 14 acres in total size and generally located within a quickly urbanizing area east of the City of Renton, King County, Washington. The evaluation and delineation of onsite and adjacent wetlands; drainage corridors, and wildlife habitats is a vital element in the planning and selection of a site development action. The goal of this approach is to assure that planned site platting does not result in adverse environmental impacts to such areas. Wetlands are generally defined as "those areas of King County that are inundated or saturated by ground or surface water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions." (King County Environmentally Sensitive Areas). STUDY PURPOSE This purpose of this document is to present the results of the onsite assessment and evaluation of the wetland/drainage corridor areas and the wildlife habitats within the project area. Included within this report is an assessment of the proposed impacts and compensatory actions to be taken to ensure that proposed onsite actions do not adversely impact environmentally sensitive areas. This study was . designed to accommodate site planning and potential regulatory actions. This report is suitable for submittal to federal, state, and local authorities for wetland boundary verification and permitting actions. SITE DESCRIPTION The project site is generally square in shape, approximately 14 acres in total size, and located within a rapidly urbanizing area generally east of the City of Renton, King County, Washington (Figure 1). The project site is comprised of two adjacent parcels; Parcel A of 11.5 acres, and Parcel B of 2.5 acres directly to the west of Parcel A. The Parcel A portion of the project site is dominated by a mature Douglas fir (Pseudotsuga menziesi,) forest plant community on the periphery that has been planted following prior forest haivest activities. A single-family dwelling is located in the northern portion of Parcel A. The center of Parcel A has· been cleared and is dominated by a dense canopy of Himalayan blackberries (Rubus procera). The southern portion of Parcel A is dominated by active livestock pasture. Parcel B portion is dominated by an active livestock pasture which also contains a single-family dwelling and four associated buildings. Evendell -1 WetlandNVBdlife Report. 00062 ·> 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 12 The project site is generally flat and rolling and a narrow drainage corridor area is present generally through the northeast corner of tlie Parcel A portion of the site. This narrow drainage corridor had been impacted by prior forest harvest actions (i.e. clearing, harvest, roadways, slash piles), and subsequent clearing and grading as part of homesite development activity. Surface drainage within this corridor is conveyed as overland flow to tl1e southeast to the ditch that runs south along the western side of 1601h Avenue South. However, there is no evidence onsite of a continuous stream channel. BACKGROUND INFORMATION NATIONAL WETLAND INVENTORY MAPPING The National Wetland Inventory (NWI) mapping completed by the U.S. Fish and Wildlife Service was reviewed as a part of this assessment. This mapping resource did not identify any wetlands or drainage corridors on the project site. (Figure 2). STATE OF WASHINGTON PRIORITY HABITATS AND SPECIES Tl1e State of Washington Priority Habitats and Species (PHS) Mapping was reviewed as a part of this assessment. This mapping resource did not identify any Priority Habitats or Species orisite or within the immediate vicinity. STATE OF WASHINGTON STREAM CATALOG The State of Washington Stream Catalog for Puget Sound was reviewed as a part of this assessment. This mapping resource did not identify any streams within the project site. This mapping did identify the Green River to the south of the project site. The Green River was identified to provide habitat for a number of anadromous and resident salmonid fish species. KING COUNTY SENSITIVE AREAS MAPPING The King County Sensitive Areas Mapping was reviewed as a part of this assessment. This mapping resource did not identify any wetland areas or streams within or adjacent to the project site. (Figure 3). SOILS MAPPING A review of the mapping of soil types within the project area completed by the U.S. Soils Conservation Service (SCS) identified that the onsite soils consist primarily of Evendell -2 Wetland/Wildlife Report· 00062 ., 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 13 Alderwood gravelly sandy loam (Soils Survey of King County Area Washington, Nov. 1973) (Figure 4). This soil is described as: Age -Alderwood gravelly sandy loam: This series consists of moderately well drained soils that have a weakly consolidated to strongly consolidated substratum at a depth of 24 to 40 inches. This soil is on uplands and formed in glacial deposits. A typical pedon of Alderwood soils from O -12 inches is dark brown (10YR 4/3) gravelly sandy loam. From 12 to 27 inches the soil is grayish-brown (2.SYR 5/2) gravelly sandy loam with many medium, distinct mottles. This soil series is not listed as a hydric soil. AERIAL PHOTO ANALYSIS Recent aerial photos of the project site were used within the background data collection process. These aerial photos identified that a coniferous forest plant community which has been altered by prior forest harvest actions dominated the majority of the project site. A deciduous forest/shrub community was identified to pass generally within a narrow corridor north to south through the central portion of the project site. This deciduous forest/shrub community appeared to continue offsite to the south until reaching the top of slope leading in the Green River Valley. A few small pockets also dominated by a deciduous forest/shrubs were present in the north-central and west central portions of the site. The project site was within an area of large-Jot single-family homesites and a number of internal roadways were present through the site. ONSITE EVALUATION -WETLANDS WETLAND STUDY METHODS Presently accepted wetland identification is based on a three parameter criteria test as established within both the Corps of Engineers Wetlands Delineation Manual (1987 Manual) and the Washington State. Wetlands Identification and Delineation Manual (Wash. Manual). These criteria are: 1. A predominance of hydrophytlc vegetation. 2. The presence of hydric soils, and 3. The presence of wetland hydrology. Initial onsite assessment and evaluation was completed during several site visits in June and. July 2000. Specific identification of wetland boundaries was completed on July 17, 2000. Assessment transects were established on a north/south pattern through the project area. Wetland assessment within the project site followed the methods and procedures outlined in both the Wash. Manual and the 1987 Manual. Onsite assessment noted that there were no differences in the identified wetland boundaries as a result to using either the Wash. Manual or the 1987 Manual. Drainage corridors were Evendell -3 Wetland/Wildlife Report -00082 ' . 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 14 assessed and identified in accordance with the criteria established by King County and the State of Washington Department of Natural. Resources (WDNR) Forest Practice Rules (WAC 222-16-030). The boundary between wetland and non-wetland areas was established by examining the transitional gradient between wetland criteria along transects through the site. Delineation was performed using the routine methodology for areas greater than five acres as detailed in the 1987 Manual. Field data sheets are provided in Appendix A. Identified boundaries were marked in the field with number flagging. These boundaries were then surveyed and made a part of the site plan mapping. FIELD OBSERVATION o Vegetation ·A mature coniferous forest plant community that had been planted following prior forest harvest actions dominated approximately two-thirds of the project site. The dominant onsite species was Douglas fir (Pseudotsuga menziesi,). These mature trees formed open stands across the treed portion of the site. Additional tree species occurring onsite included Westem red cedar (Thuja p/icata), Western hemlock (Tsuga heterophylla), big leaf maple (Acer macrophy/lum), red alder (A/nus rubra), black cottonwood (Popu/us trichocarpa), cherry (Prunus spp), and cascara (Rhamnus purshiana). The understory included a wide variety of shrubs and herb species including vine maple (Acer circinatum), salal (Gaultheria shallon), Oregon grape (Berberis spp.), hazelnut (Cory/us comuta), salmonberry (Rubus spectabilis), Scot's broom (Cytisus scoparius), Himalayan blackberry (Rubus procera), evergreen blackberry (Rubus /aciniatus), Pacific red elderberry (Sambucus racemosa), snowberry (Symphoricarpus a/bus), bracken fern (Pteridium aquilium). and sword fern (Polystichum munitum). Throughout the project site this plant community had been altered by prior forest harvest actions. This plant community was identified as non-hydrophytic (i.e. typical of non-wetlands). The central area of Parcel A was dominated by dense stands of Himalayan blackberry. This area had apparently been cleared of the tree canopy in the recent past, and the blackberry had colonized after the clearing. The plant community within the central drainage corridor (Wetland A) that was identified to generally pass from north to south through the site was dominated by a young, mixed deciduous forest and emergent plant community. This plant community had also been altered by prior forest harvest and grading actions which had removed the mature trees, created slash piles, and created an internal drag-road across this drainage. Observed tree species included sapling red alder, Western red cedar, black cottonwood, Oregon ash (Fraxinus latifolia), and Pacific willow (Salix /ssiandra). The understory was dense and included salmonberry, Douglas spiraea (Spiraea doug/asil), Western crabapple (Pyrus fusee), Sitka willow (Salix sitchensis), slough sedge (Carex obnupta),horsetail Evendell-4 Wetland/Wildlife Report. 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 15 (equisetum arvensis), buttercup _ (Ranunculus repens), reed canarygrass (Phalaris arundinacea), softrush (Juncus effusus), and lady fern (Athyrium filix-femina). This plant association was identified as hydrophytic in character (i.e. typical of wetlands). o Soils As identified by numerous sample plot$ throughout the project site, the majority of the site exhibited a soil profile typical of the Alderwood _soil series. The soil was defined as gravelly sandy loam with a soil matrix color of dark brown (10YR 3/3) to brown (10YR 4/4). These soils did not exhibit redoximorphic features such as prominent soil mottles, oxidized root channels, or glayed soil layers within the first 20 inches of soil depth. The majority of the project site exhibited soil which would not be considered "hydric." Representative sample plots are identified on Figure 4. (Special note -many more sample plots were completed during the field assessment than are shown within Figure 4 or reported within Appendix A). Sample plots within the defined drainage corridor that was identified to generally pass from north to southeast through the northeast corner of the site exhibited a mixed gravelly loam soil texture. These soils appeared to be mineral in character. Soils ranged in color from very dark brown (10YR 3/1) to dark grayish brown (10YR 4/2). Redoximorphic features were present and often very prominent. Soils within these areas exhibited "hydric" characteristics. o Hydrology Onsite hydrology appeared to be the result of seasonal stormwater runoff from onsite and adjacent properties. In addition, the pattern of surface water movement appeared to have been modified by prior land use activities. These activities have included the development of offsite homesites, the development of roadways and. utilities, and the placement of culverts. The general movement of surface water runoff across the site was generally to the south. The movement of surface water through the central drainage corridor did not form a continuous drainage pattern and no areas within these swales exhibited characters typical of a "stream." This area had also been impacted by an internal roadway and draglines and logging slash piles. Based on field indicators (i.e. water stained leaves, drift lines, surface water, soil saturation, oxidized root channels, wetland drainage pattern) this drainage corridor met the wetland hydrology criteria of the 1987 Manual and the Wash. Manual. Wrthin an area located in the north-central portion of the site, directly south of the homesite and past the edge of the landscaping, pooled water was also documented. This area was in a small, isolated depression, and had been impacted by prior land use actions (i.e. root pull up, slash pile, compaction). However, based on field indicators (i.e. water stained leaves, drift lines, soil saturation, oxidized root channels, wetland Evendell-5 WetlandNl/ildlife Report· 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 16 drainage pattern) these isolated depressions met the wetland hydrology criteria of the 1987 Manual and the Wash. Manual. WETLAND AND STREAM DETERMINATION Wetland determination was based on sample plots which contained hydrophytic vegetation, hydric soils, and wetland hydrology in accordance with the 1987 Manual and the Wash. Manual. Based on these methods one wetland area was identified onsite (Figure 4). No area was identified onsite to exhibit characters typical of a "stream· (i.e. a continuous pattern of surface water movement, either permanent or intermittent). WETLAND SIZEONSITE CLASSIFICATION KING COUNTY FUNCTION STANDARD (square feet) (USFWS) RATING AND VALUE BUFFER RATING WIDTH A 17.162sqft PFOE, PEME 2 low 50 feet PFOE palustnne, forested, seasonally flooded/saturated PEME palustrine, emergent, seasonallY,flooded Wetland A: This wetland was identified within a topographic drainage that passed generally from the central northern boundary to southeast through the northeast corner of the project site. · This wetland complex was dominated by a young, mixed deciduous forest and emergent community that had formed following prior forest harvest and grading activities. This plant community was very dense in the southern end and open on the north end. This wetland complex exhibited shallow ponded surface water during the winter and early growing season as a result of topography, the internal logging road and draglines, a created berm, and an offsite roadway culvert. Soil saturation to the surface was noted to occur within a majority of this wetland complex into the early part of the growing season. As noted by a slash pile within this area forest harvest activities had been undertaken within this wetland complex. This wetland plant community ended adjacent to, but separated from, the roadside berm to 1601h Avenue South to the south. Wetland A was identified to meet the U.S. Fish and Wildlife Service (USFWS) criteria for classification as palustrine, forested, seasonally flooded(PFOC) and palustrine, emergent, seasonally flooded/saturated (PEME). Based on the young ·forested plant community this wetland complex was identified to meet the criteria for designation a King County Class 2 Wetland. WETLAND FUNCTION AND VALUE ASSESSMENT Wetlands are known to perform significant roles in the ecosystem, some of which are of immediate value to society. These roles vary greatly with the size, type, hydrology, vegetation, and location of wetland areas. Although.the ecological functions performed by this wetland are complex, interrelated, and difficult to assess and quantify, methods Evende/1-6 Wetland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 17 have been developed for the U.S. Army Corps of Engineers (Adamus et al. 1987: Reppert etal. 1979). The functions provided by wetlands include hydrologic support, shoreline protection, stormwater and floodwater storage, water quality, groundwater recharge, and provision of wildlife habitat. The HYDROLOGIC SUPPORT FUNCTION is defined by the measure of hydrologic stability and environmental integrity which the wetland provides. This function is measured by the frequency of inundation and saturation by tidal actions, stream flow, runoff, and precipitation. Wetlands permanently inundated or saturated, or intertidal wetlands are valued as high. Medium valued wetlands are seasonally flooded or are open water systems that remain saturated during most of the growing season. Wetlands that are intermittently flooded or hydrologically isolated are considered of low value. The SHORELINE PROTECTION FUNCTION is defined by the measure of shielding from wave action, erosion, or storm damage which a wetland provides. This function is measured by the location and width of the wetland along shoreline areas, types of vegetation present, and the extent of development along the shoreline. A high value is given to wetlands along a shoreline that have a width greater than 200 yards and dense woody vegetation. A medium value is given to a wetland with a width of 100 to 200 yards, sparse woody vegetation, and dense emergent vegetation. Wetlands less than 100 yards in width and emergent or lacking vegetation are considered of low value. The STORMWATER AND FLOODWATER STORAGE FUNCTION is defined by the ability of a wetland to store water and retard flow during periods of flood or storm discharge. Wetlands of larger size are generally considered to have greater ability to provide this function. In addition, wetlands nearer to urban or potentially develop-able areas are also considered to provide greater flood protections than wetlands which are in undeveloped areas. The WATER QUALITY FUNCTION is defined by the physical, biological, and chemical processes which wetlands provide to naturally purify water. This function removes organic and mineral particulates through natural filtration. In general, wetlands of greater size, more dense vegetation, and those which are close to point sources of pollution are considered to be of higher value. Wetlands which are small (<5 acres), lacking dense vegetation, and not close ta point or non-point sources of pollution are considered of low value. The GROUNDWATER RECHARGE FUNCTION is defined by the interaction of the underlying geology and soils, and the surface topography. This function provides for the movement of surface water into groundwater systems. Important to this function is wetland size, period of inundation, and depth of standing water within the wetland. High value is given to permanently inundated wetlands greater than 10 acres in size. Medium value is given to wetlands which are Evendell-7 WetlandNVildlife Report -00062 • 05/10/2004 15:08 2535390514 SDUNDBUILT HOMES PAGE 18 seasonally flooded and 5 to 10 acres is size. Wetlands less than 5 acres in size, isolated, and temporarily saturated are considered of low value. The NATURAL BIOLOGICAL FUNCTION is defined by the complexity of physical habitats and biological species within the wetland area. The value given to a wetland depends upon its ability to provide habitat for nesting (spawning), incubation, feeding, rearing, and cover of aquatic and terrestrial animal and fish species. In addition, the ability of a wetland to provide support for varying food chains is an important element in value assessment. Wetlands of high species diversity, three or more habitat types, unique habitat features, large in size, and . associated with a permanent stream or tidal marsh are considered of high value. Wetlands with moderate species diversity, two habitat types, moderate in size, and associated with an intermittent stream or high salt marsh are considered of medium value. A low value is given to wetlands of low species diversity, small size, and isolated. These six functions are rated low, moderate, or high, based on the criteria outlined above. These criteria are guidelines compiled from Adamus (1987)and Reppert (1979) and professional judgment must be exercised in assessing these criteria. Overall values for a wetland are assigned, based on a synthesis of individual values. In addition to intrinsic functions, extrinsic functions are also recognized. These extrinsic functions provide social values that have indirect benefits to wetlands. Education and recreational opportunities are most often mentioned as extrinsic functions. Associated values are often subjective and are thus difficult to evaluate. As such, these functions are not rated, but are nonetheless important when considering creation, restoration, or enhancement projects. ONSITE WETLAND VALUATION Following the function and value assessment process noted above Wetland A was rated as exhibiting a low rating: 0 Water Quality Benefits -This wetland was small, isolated, and had been impacte_d by prior forest harvest and clearing. This wetland appeared to retain less than 25% of the runoff which occurred within the local area. This wetland also exhibited a limited vegetation density as a result of prior forest harvest and grading. The primary water quality benefit provided by this wetland was a very limited amount of biofiltration of surface stormwater. o Stormwater Storage -This wetland appeared within a topographic depression and had been impacted by prior land uses. This wetland was located in a rapidly developing part of King County. This wetland was small and exhibited a very limited ability to store stormwater. Evendell-8 Wetland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 19 o Hydrologic Support -This wetland appeared small, isolated, and to pond a limited amount of surface water early in the growing season. Evidence of seasonal ponding and saturation to the surface was limited. o Groundwater Recharge -This wetland appeared small, isolated, and to pond a limited amount of surface water early in the growing season. Evidence of seasonal ponding and saturation to the surface was limited. o Natural Biological Function · This wetland was small, isolated, and exhibited a very limited range of plant diversity and vegetation complexity. Available habitat was dominated to young deciduous trees and a dense .shrub community. Unique habitat features (i.e. snags, fallen trees, mature trees along the wetland boundary) were absent. This wetland included a large slash pile resulting from prior forest harvest. ONSITE EVALUATION -WILDLIFE WILDLIFE STUDY METHODS The onsite assessment of wildlife species presence and available wildlife habitats was completed as a part of the onsite assessment of wetland characteristics. This assessment included both early morning and late afternoon observations. Species presence and habitat utilization were evaluated following the methods identified by Horner and Raedeke (1989) and within U.S. Fish and Wildlife Service Publication 80/58 (Mikol, 1980). In addition, the King County Wildlife Study Guidelines (Draft Wildlife . Management in King County, Issue Paper, 1993) were also followed to assure consistency with the King County permit process and documentation of habitat types. Onsite activities documented observations of individual species presence, the general location of the species sighting, and the life history activity being undertaken. Sample stations were established within the site for these observations. This range of observations were documented because for many of the smaller, less mobile species (i.e. small mammals, amphibians) the project site may provide all of their life history requirements (nesting, cover, feeding, and reproduction) while for the more mobile species (i.e. waterfowl, songbirds, medium sized mammals) the project site may be used for only a few of the life history requirements. These more mobile species may depend more upon adjacent habitat for more critical habitat needs such as nesting and cover from predators. It is unlikely based upon the existing site conditions, coupled with adjacent land uses, that species which require large areas of undisturbed habitat would exist onsite. Evendell-9 Wetland/Wildlife Report. 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 20 ONSITE HABITAT TYPES The site exhibited one primary habitat type that had been manipulated as a part of past land use activities. An upland coniferous forest plant community dominated this primary habitat type. This plant community had been retained following prior forest harvest activities. Included within this primary habitat type were two additional habitat types. As defined by King County, the "habitat type" best represented within the site was "Conifer Upland Forest -low understory. • The primary tree within this habitat type is Douglas fir that is 80 to 200 years old with a well developed understory. One additional habitat type was Persistent Lowland shrub. This upland habitat type has been manipulated and modified by prior forest harvest activities. In parcel B, and in the southern portion of parcel A, the areas were developed into active pastures, and qualify as Agricultural lands under the County designation. The adjacent properties also exhibited similar land use actions along with the development of single family homesites. The "deciduous forested wetland" habitat type was identified as present within the central drainage corridor (Wetland A). This habitat type had also been impacted by prior forest harvest activities and adjacent land uses. This habitat type included young deciduous trees (i.e. red alder, black cottonwood, Oregon ash, Pacific willow) and a wide variety of shrubs and herbs (i.e. Douglas spiraea, salmonberry, willows, sedges, rushes, reed canarygrass, lady fern, buttercup). PRIMARY HABITAT TYPES INCLUDED MINOR HABITAT TYPES Conifer Upland Forest Deciduous Forested wetland -low understorv . Aaricultural Lands Persistent Lowland Shrub PLANT AND ANIMAL SPECIES OBSERVATIONS Conifer Upland Forest: The majority of the 14-acre project site was identified to be dominated by a coniferous upland forest plant community. Total crown cover exceeded 60 percent. The primary tree species was Douglas fir that had been retained following prior forest harvest. Additional tree species include Western hemlock, big leaf maple, western red cedar, hawthorn, cascara, black cottonwood, and red alder. The understory was dense and composed of a wide variety of shrubs and herbaceous species. Avian species observed within this coniferous upland forest habitat type included tree swallow (Tachycineta bicolor}, song sparrow (Melospiza melodia), dark eyed junco (Junco hyema/is), American crow (Corvus brachynchos), American robin (Turdus migratorius), golden crown kinglet (Regulus satrapa), bushtit (Psaltriparus minimus), house finch (Passer domesticus), Steller's jay (Cyanocitta ste/fen), pine siskin (Cardue/is pinus), black-capped chickadee (Parus atricapillus), brown creeper (Certhia americana), ruffed grouse (Bonasa umbelfus). varied thrush (lxoreus naevius), rufous sided towhee (Pipi/o erythrophtha/mus), Northern flicker (Co/aptes auratus), and hairy woodpecker (Picoides vi//osus). These avian species were feeding throughout this Evendell -10 Wetland/Wildlife Report • 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 21 habitat type with the greatest number of observations noted along the edge between this upland forested habitat type and the mixed wetland areas. This habitat type also appeared to provide cover to many species that also used the adjacent areas, particularly the residential areas. A number of nests were observed onsite and appeared to have been used during the 2000 breeding season. A limited number of stumps and snag trees are present within this plant community. These stumps and snags appeared well utilized as feeding areas by a wide variety of avian species, particularly hairy woodpeckers, creepers, and Northern flicker. A few of these snags also exhibited a limited use by pileated woodpecker (Drpocopus pileatus). Mammal species observed within this habitat type included deer mouse (Peromyscus manicufatus), shrew (Sorex spp.), opossum (Dide/phis virginianus), Douglas squirrel (Tamiasciurus dougfasii), mountain beaver (Aptodontia rufa), raccoon (Procyon lotor), and black tailed deer (Odocoileus hemionus). Freshwater Deciduous Wetland: A deciduous wetland area was identified to pass generally from north to southeast through the northeastern portion of the project site. This wetland represented less than 5% of the total project area, had been greatly modified by prior forest harvest activities, and was dominated by a young mixed forest composed of red alder, black cottonwood, and Pacific willow trees. Crown cover exceeded 50% in some areas where dense thickets of sapling red alder trees, Douglas spiraea, and salmonberry dominated. The northern portion of this area had been cleared and graded and .was dominated by herbaceous species. This grading has enhanced an existing swale that ran through the property. Avian species observed within this freshwater wetland habitat type included tree swallow, violet green shallow (Tachycineta thal/assina), barn shallow (Hirundo rustica), song sparrow, dark eyed junco, American crow, American robin, golden crown kinglet, house finch, Stelle r's jay, pine sis kin, black-capped chickadee,· rufous sided towhee, Northern flicker, pileated woodpecker, and hairy woodpecker. These avian species were noted to use the "edge" between the mixed wetland habitat type and the upland young conifer forest habitat type. Many of these avian species were feeding, nesting, and seeking cover either within the forested portions of this wetland habitat type or within the adjacent upland forest plant community. This wetland plant community included . a number of downed logs and a-slash pile. These habitat features were noted as heavily used as feeding areas·, cover, and perches. A number of small cavities were also noted to be used by swallows. Mammal species observed within this habitat type included deer mice, opossum, black tailed deer, and raccoon. E11endell -11 Wetland/Wildlife Report -00062 • 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 22 Pacific tree frogs (Hyta regilla) were also noted within this habitat type. As identified the apparent length of surface water ponding resulting from water retention by the wetland would be inadequate to provide spawning habitat for this species. MOVEMENT CORRIDORS As identified by onsite wildlife trials, small and medium size mammals appeared to be moving throughout the project site and into the adjacent areas. The larger of these trails (many of which are loggir:ig roadways and draglines) also appeared to be used by domestic cats, domestic dogs, horses, and neighbors. Wetland A also appeared to serve as a movement corridor for a wide variety of wildlife species. PRIORITY SPECIES Two wildlife species identified by the State of Washington as "Priority Species" were observed onsite during this assessment. Black tailed deer and ruffed grouse are noted by the State of Washington as a "priority species" because these species are regulated as "game" species. The project site may also provides suitable habitat for other game species such as mourning dove (Zenaida marroura) and band-tailed pigeon (Columba fascfata). STATE CANDIDATE SPECIES A single "State Candidate" species -the pileated woodpecker -was observed to utilize the forested wetland area along with the adjacent upland forested areas onsite. State candidate species are presently under review by the State of Washington Department of Fish. and Wildlife (WDFW) for possible listing as endangered, threatened, or sensitive. WDFW has developed a list of recommendations for management of the pileated woodpecker that focused on the preservation of nesting habitat. As defined by WDFW the most popular nest trees are typically hard snags with bark and broken tops within riparian areas. , REGULATORY CONSIDERA TIOI\I The proposed alteration of lands defined by various federal, state, and local authority rules and regulations as "wetlands" raises environmental concerns that are generally addressed in the development review process. These concerns center around the development's potential adverse impacts to the structure, function, value,· and size of these "wetland" areas. Such adverse impacts may include a reduction in wildlife habitats, reduced surface water quality, reduced water retention, a reduced ground water recharge rate, reduced plant species diversity, and the reduction in the function and value of other associated wetland and non-wetland characteristics. Evendell -12 Wetland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 23 U.S. ARMY CORPS OF ENGINEERS -Section 404 Section 404 of the Clean Water Act (33 U.S.C. 1344) prohibits the discharge of dredged or fill material into 'Waters of the United States" without a permit from the Corps of Engineers (Corps). The Corps has jurisdiction over freshwater systems waterward from the ordinary high water line of a water body or waterward from the upland boundary of the adjacent wetland. The definition of fill materials includes the replacement of aquatic areas with dry land, grading which changes the surface contour of a wetland, and mechanized land clearing in wetlands. For the purposes of Section 404 permitting the Corps makes the final determination as to whether an area meets the wetland definition and would be subject to regulation under the Corps program. Currently the Corps has two specific types of permits which apply to wetland fill proposals. These two types are a series of specific Nationwide Permits and the Individual Permit. The Nationwide Permit process identifies specific categories of work that can be undertaken following a set of specific conditions applicable to each Nationwide Permit number. For example; NWP#12 allows for the limited, short term impacts to wetlands for the placement of utilities, and NWP#14 allows for a limited impact to wetlands as a part of the development of a roadway crossing. The Corps has noted several times within information papers, documents, and workshops that a project proponent that places fill within a wetland without specific Corps authorization does so at the proponent's own risk. The Corps requires an Individual Permit where a proposed activities within an identified jurisdictional wetland area can not be.authorized under one of the Nationwide Permits. Within the Individual Permit process the Corps undertakes a much more in- depth review of the proposed project and the proposed impacts. The Corps must evaluate whether the benefits derived from the project outweigh the foreseeable environmental impacts of the project's completion. · KING COUNTY -"Environmentally Sensitive Areas" Ordinance 21A.24 • Wetland and Stream Classes King County regulates activities in and around wetland areas. Such regulations also require that an undisturbed native vegetation buffer be retained along the upland side of the identified wetland areas. To assist in this regulation the County has defined classes by which to regulate wetlands, streams, and their associated buffer area. These categories are based on such features as size; the presence ·of endangered or threatened plants, fish, or animals; regionally rare wetlands; wetlands of local significance for wildlife or stormwater functions; the number of wetland classes and subclasses; and percentage of open water. A Class 1 Wetland means a wetland assigned the Unique/Outstanding rating in the King County Wetlands Inventory, or any wetland which meets any of the following criteria: Evendell -13 Wetland/Wildlife Report • 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 24 '·-· 1. The presence of species listed by the federal government or state as endangered, or threatened, or the presence of critical or outstanding actual habitat for those species; · . 2. Wetlands having 40% to 60% permanent open water in dispersed patches with two or more classes of vegetation; 3_ Wetlands equal to or greater than ten acres in size and having three or more wetland classes, one of which is open water; or 4_ The presence of plant associations of infrequent occurrence. A Class 2 Wetland means a wetland assigned the Significant #2 Rating in the King County Wetlands Inventory; or any wetlands which meet any of the following criteria: 1. Wetlands greater that one acre in size; 2: Wetlands equal to or less that one acre in size and having three or more wetland classes; 3. Wetlands equal to or less than one acre that have a forested wetland class; 4. The presence of heron rookeries or raptor nesting trees_ A Class 3 Wetland· means a wetland assigned a Lesser Concern #3 Rating in the King County Wetlands Inventory, 1983, or uninventoried wetlands that area equal to or less than one acre in size and that have two or fewer wetland classes. A Class 3 Stream means those streams that are intennittent or ephemeral during years of normal rainfall and are not used by salmonids. • Wetland/Stream Alteration King County allows a limited amount of alterations to wetlands provided all impacts are mitigated pursuant to an approved mitigation plan. For example, on a site larger than 20 acres in size, up to three isolated wetlands may be altered by combining their functions into one or more replacement wetlands pursuant to an approved mitigation plan (21A.24.330.K)_ The County defines an "isolated wetland" as those Class 3 Wetlands whose total size is less than 2,500 square feet and which area hydrologically .isolated from other wetlands or streams. • Roadway Improvements King County will allow a roadway to cross a wetland or associated buffer where the following are met (21A.24.330.N):. 1. King County determines that no alternative access is practical; 2. all crossings minimize impact to the wetland and provide mitigation for unavoidable impacts through restoration, enhancement, or replacement of disturbed areas; · Evendell • 14 Wetland/Wildlife Report -00062 ' 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 25 3. crossings do not change the overall wetland hydrology; 4. crossings do no diminish the flood storage capacity of the ~etland; and 5. all crossings are constructed during summer low water periods. o Required Buffers King County has established a standard buffer to be applied to a wetland or stream to assure protection of the wetland function and value. This buffer area is measured perpendicular to the defined wetland edge or perpendicular to the identified ordinary high water mark of a stream. WETLAND CLASS STANDARD BUFFER WIDTH 1 100 feet 2 50 feet 3 25 feet King County allows the standard buffer to be modified where such actions would provide additional protection to wetlands or enhance the wetland's functions (21A.24.320.B). Buffer averaging may be allowed as long as the total area contained in the buffer on the development proposal site does not decrease and the minimum width of the final buffer is not less than 65% of the standard buffer width. SELECTED ACTION PLAN The Selected Action Plan of the Evendell Residential Community focuses on the creation of independent lots suitable for the development of single-family homesites consistent with the King County Comprehensive Plan. An essential element of this process is the development of access roadways and utility corridors which both meet King County health and safety standards and meet the goal of avoidance and minimization of potential short-term or long-term adverse impacts to aquatic environments. A primary feature in the creation of these homesite lots will be the establishment of a protective buffer adjacent to the identified onsite wetland consistent with the King County Environmental Sensitive Areas Ordinance. The creation of these homesite lots will not require the adverse impact or placement of fill within identified wetland areas. To provide additional protection for the onsite wetland, the buffer in the northwest corner · will be increased by the addition of 15,495 square feet. Through averaging, the buffer on the west side of the wetland will be reduced to 32.5 feet, a total of 9,340 square feet. Through buffer averaging these unavoidable intrusions into the standard buffer areas will be fully compensated and will not adversely impact the adjacent wetland areas. ) The development of this residential community will require the creation of a public roadway access by extending the existing 1581h Avenue South roadway which presently Evendell -15 Wetland/Wildlife Report -00062 . , 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 25 ends at Southeast 136th. In addition, site development requires improvements to the existing right-of-way (SE 135th Street -a primary collector route for the area) which fronts the project along its northern boundary. This will require the unavoidable filling of the northern 200 square feet of Wetland A and the reduction of the buffer associated . with this area of the wetland by 4,649 square feet. Through restoration of the existing onsite wetland, additional of buffer area along the eastern side of Wetland A, and onsite erosion protections these unavoidable intrusions into the wetland and standard buffer areas will be fully compensated and will not adversely impact the remaining wetland area . ELEMENTS OF THE COMPENSATORY MITIGATION PLAN Site planning for the Evendell Residential Community project site has focused on the mandated hierarchy of wetland impact reduction: 1) avoidance, Z) minimization, and 3) compensation. These avoidance and ;minimization strategies included a site design to reduce impacts to onsite wetland systems . . The total amount of wetland area to be unavoidably modified by this project equals 200 square feet. As compensation for this unavoidable impact to Wetland A resulting from the development of SE 136th Street approximately 4,000 square feet of existing degraded wetland area will be enhanced through the planting of native trees and shrubs. The presently degraded buffer adjacent to the restored wetland area will also be restored and enhanced. Through buffer averaging the final protective buffer will be established to ensure that there is no reduction in the total area of buffer onsite and that the final buffer enhances the on site wildlife habitats and greater long-term protection of the wetland. PROJECT EL.EMENT IDENTIFIED IMPACT Reduction of the standard 50 9,340 sqft of buffer fool buffer along the western eliminated edge of Wetland A to 32.5 feet. Elimination of 4,649 square 4,649 sqfl of buffer feet of buffer along the eliminated northern edge of Wetland A to develop SE 136th Street. Elimination of 200 square feet 200 sqft of wetland of buffer along the northern eliminated edae of Wetland A to develop COMPENSATION PROVIDED 10,000 square feet of buffer will be added to the eastern side of Wetland A. This addition of buffer will provide greater protection to the wetland through the addition of mature trees and a very dense vegetation communitv 5,495 square feet of buffer will be added to the eastern side of Wetland A. This addition of buffer will provide greater protection to the wetland through the addition of mature trees and a very dense vegetation community The existing degraded part of Wetland A onsite will be enhancement with the Planting of native trees and shrubs. Evendell-16 Wetland/Wildlife Report • 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 27 I SE 1361" Street. DESCRIPTION C>F THE COMPENSATORY MITIGATION PROGRAM 1. As compensation for the unavoidable impact to 200 square feet of onsite King County Class 2 Wetland a presently degraded area of wetland adjacent the existing homesite equal to 4,000 square feet will be restored. Wetland restoration will be accomplished through the planting of native trees and shrubs. In addition, site design will ensure that there will be no adverse changes in the existing wetland hydrology patterns (Attachment 1). 2. The buffer associated with the identified onsite wetland will be established and identified onsite. The width of the protective buffer area shall be averaged so the total square footage surrounding the buffer does not decrease and that additional protection to the wetland is provided. Along the western buffer boundary the buffer width will be reduced to 65% of the standard buffer width for a Class 2 Wetland, to 32.5 feet as measured perpendicular for the identified wetland boundary. For the eastern buffer boundary, the buffer width will be increased to a maximum of 100 feet, and will encompass the entire comer to the project site. Once identified the wetlands and associated buffers will not be adversely modified by future land use actions. 3. As a part of the development of the required roadway improvements the actual encroachment into buffer area of Wetland A will be held to the minimum necessary to meet County roadway requirements along the SE 1361h Street Corridor. Following placement of the roadway improvements the roadway side slope within the buffer areas will be seeded with the defined grass seed mixture (Attachment 1). 4. As compensation for the unavoidable encroachment into the buffer associated with Wetland A as a part of the development of SE136th Street the standard buffer along the east side of this wetland will be increased. This buffer width increase is designed enhance the . wetland's function through improved visual and auditory blockage from the street crossing and greater wildlife habitat opportunities. 5. As a part of the development of the required roadway improvements the actual encroachment into buffer area of Wetland A will be held to the minimum necessary to meet County roadway requirements along.the SE 1361h Street Corridor. Following placement of the roadway improvements the roadway side slope within the buffer areas will be seeded with the defined grass seed mixture (Attachment 1). 6. All onsite activities will be monitored by the onsite biologist. The onsite biologist shall identify planting locations and planting patterns within the restored wetland and buffer. Following the completion of onsite planting activities a "record-drawing" plan will be prepared and submitted to King County .. A five-year monitoring program will be undertaken to assure the success of the compensatory mitigation plan. A project Evendell -17 Wetland/Wildlife Report -00062 ' 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 28 financial guarantees will also be implemented to assure that the proposed work is completed and is successful. 7. Temporary and long-term erosion control measures will be implemented .. These measures include silt fencing during site preparation and wetland construction, and seeding of exposed soil areas. B. The outer boundary of the wetland buffer will be marked and fenced to limit intrusion into these areas. GOAL ANO OBJECTIVE OF THE MITIGATION PLAN The GOAL of the Compensatory Mitigation Plan is to fully compensate for the unavoidable adverse impact to 200 square feet of wetland area and to enact a buffer averaging program that provides greater protection to the onsite wetland. This wetland area meets the criteria for designation as a King County Class 2 Wetland and presently exhibits a low function and value rating. The proposed restored wetland area will be within with the northern portion of Wetland A will provide full compensation for unavoidable project impacts while also enhancing the function and value of the wetland. Upon the completion of this mitigation plan there will be no net loss of King County regulated wetland functions or values, an increase in the potential for the buffer to protect aquatic habitats, and an increase in the potential to provide long- term protection of wetland and buffer areas through an enhancement of a degraded wetland. To achieve the defined GOAL, the following OBJECTIVES are defined: • Plant Community Structure A. The enhanced compensatory mitigation wetland area will total 4,000 square feet and will exhibit a scrub/shrub and sapling tree vegetation classes within five years following initial planting (palustrine, scrub/shrub, seasonally flooded -PSSC). • Natural Biological Attributes B. The compensatory mitigation wetland and the associated buffer will include the placement of snags and downed logs which provide nesting and cover habitat for passerine birds common to the area within five years. PERFORMANCE CRITERIA Evendell -18 Wetland/Wildlffe Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 29 To establish whether the defined project OBJECTIVES have been met by the wetland mitigation plan. the following PERFORMANCE CRITERIA have been established to apply to the compensatory mitigation wetland area. Objective A. The compensatory mitigation wetland· area will total 4,000 square feet in size and will exhibit scrub/shrub and sapling vegetation classes within five years following initial planting (palustrine, scrub/shrub, seasonally flooded -PSSC). Performance Criteria: As defined by Canopy Coverage Method sampling (0.25 m2 plot frame) the emergent plant community within the 4,000 square feet of the compensatory mitigation wetland area will exhibit at least an 80% coverage within five years following initial planting. As defined by Line- intercept Method sampling the scrub/shrub and sapling vegetation class will exhibit at least a 50% aerial coverage within five years following initial planting in those areas not identified as open water. · Performance Criteria: At the end of the first growing season 100% of the installed trees and shrubs will be alive and exhibit growth. Those species identified as dead will be replaced prior to the start of the second growing season. Performance Criteria: At the end of the fifth growing season 80% of the trees and shrubs (species combined) will be alive and exhibit growth. Objective B. The compensatory mitigation wetland and the associated buffer will include the placement of snags and downed logs which provide nesting and cover habitat for passerine birds common to the area within five years. Performance Criteria: A minimum of three (3) stumps (minimum 10 feet in length, minimum 20 inch diameter at the top, minimum 1 O foot diameter at bottom of rootball) and a minimum of three (3) downed logs (minimum 20 feet in length, minimum 20 inch diameter at 10 feet above root collar, minimum 10 foot diameter at bottom of rootball) will be placed within the compensatory mitigation area to provide habitat for passerine birds common to the area. (Appendix B). Performance Criteria: The compensatory mitigation area will be used for cover by at least two species of passerine birds common to the area within five years of completion of construction of the mitigation area.· This will be monitored through observations and photographs of individual birds and habitat utilization. MITIGATION REPLACEMENT/ENHANCEMENT Evendell -19 WetlandNVndlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 30 The selected mitigation area will make an improvement to the functions and values offered by the existing onsite wetland and buffer while also providing a wider range of functions and values not presently exhibited onsite. Primary features offered by the selected mitigation plan includes a higher functioning wetland area, greater water quality protection to downstream resources, greater opportunity for biofiltration of surface water, greater water storage capacity, greater diversity of plant species and plant community associations, greater diversity of wildlife habitats. Overall, the proposed mitigation plan will provide a higher quality and a wider range of functions and values per unit area that presently exiting onsite within Wetland A. The proposed mitigation plan offers the opportunity to replace existing low function wetland with an area of greater functions and values. In addition, provisions will be put into place that will allow for the long-term protection and preservation of the entire wetland mitigation area, together with monitoring to ensure that the plant communities and wetland hydrology features are established. SUMMARY TABLE OF WETLAND FUNCTIONAL BENEFITS MITIGATION ELEMENT WETLAND FUNCTION BENEFITS Establishment of a diverse plant community • Natural Biological Function and habitat features within the wetland and • Water Quality buffer areas. Enhancement of the mitigation wetland area • Hydrologic Support through selective site excavation. • Stormwater & Floodwater Storage • Water Quality • Natural Biological Function • Groundwater Rectiarqe Removal and management of invasive • Water Quality soecles. • Natural Biolo11ical Function Use of temporary and long-term erosion • Water Quality control technolonv. SELECTED PLANT COMMUNITIES The plant communities and plants selected for the created wetland and restored/ enhanced wetland and buffer areas will be obtained as nursery stock. These selected species are native and commonly occur in the local area. The plant species are selected to increase plant diversity, match present onsite communities, increase wildlife habitats, and enhance the aquatic environment. NUMBER COMMON NAME LOCATION SCIENTIFIC NAME 20 Western red cedar (THP) Wetland and Thuia n//cata buffer PROPOSED PROPOSED INDICATOR SPACING locl SIZE STATUS 12-15fl 5 ft height FAC minimum Evendell -20 Wetland/WIidiife Report -00062 05/10/2004 15:08 2535390514 :SOUNDBUILT HOMES PAGE 31 20 Sitka spruce (PIS) Wetland and 12-15/t 5 ft height FAC Picea sitchensis buffer minimum 10 Oregon ash (FRL) Wetland 10-15/t 4 ft height FACW Fraxinus /atifolia minimum 20 Black Winberry (LOI) Wetland and 4 ft 2 gal FAC"" Lonicera invo/ucrata buffer 20 Pacific ninebark {PHC) Wetland 4 ft 2 gal FACW- Ph=ocamus caoitatus 20 Red-osier dogwood {COS) Wetland 4 ft 2gal FACW Comus stolonifera 20 Salmonberry (RUS) Wetland 4 ft 2gal FAC+ Rubus soectabi/is 20 Sitka willow (SAS) Wetland 10-15/t 2 gal FACW Sa/ix sitchensis SEEDING MIXTURES Wetland Area Soil Moisture Conditions Common name Scientific name cercent b" welaht Redtoo Aarostis alba 50% Water foxtail Alooecurus oenicu/atus 50% apply at the rate of 120 pounds per acre Upland Buffer Area Soil Moisture Conditions Common name Scientific name nercent bv weiaht Colonial bentQrass Aorostis tenuis 15% Tall fescue Festuca arundinacea 40% Perennial rvearass Lolium perenne 30% Creeoina red fescue Feistuca rubra 15% apply at the rate of 120 pounds per acre CONSTRUCTION INSPECTION Essential to the success of the compensatory mitigation plan is the accurate inspection of onsite activities immediately prior to and during the construction phase. These activities include pre-construction site inspection, onsite inspection and technical direction during construction and planting activities, and post-construction site inspection and evaluation. The pre-construction site inspection allows the project proponent and the project biologist to evaluate and, if necessary, adjust the onsite construction steps. These steps include analysis of project site elevation features, project sequencing and timing, final grade analysis, unforeseen required minor modifications to the original establishment plan, and the establishment of environmental protections (silt fences, etc.) required during construction. Interaction with King County wetland staff is also an Evendell • 21 Weiland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 32 essential element during pre-construction site inspections and discussions. Onsite technical inspection during construction and planting activities will be implemented by the combined efforts of the project biologist and King County wetland staff. The project biologist will perform construction oversight and address minor unforeseen construction difficulties to assure that the intent of the buffer establishment plan is met The project biologist shall also be responsible for assuring that the species and sizes of native plants selected and noted within the final planting plan are utilized during construction. The project biologist shall also be responsible for the placement of all trees and shrubs. If selected native species become unavailable, the project biologist will consult with King County wetland staff for substitute plant _species to assure that the intent of the stream buffer establishment plan is met. Post-construction site inspection/ evaluation will include the preparation of a "record-drawings" which will be submitted to King County wetland staff. WATER QUALITY PROTECTIONS DURING CONSTRUCTION The project team will implement a wide range of water quality protective measures during and immediately following the construction of the compensatory mitigation area. This protective measures include the placement of appropriate silt fencing along the outer boundary of the buffer area to be established, short-term silt fencing adjacent to the specifically identified wetland and buffer excavation areas, work during the drier season of the year, the use of well maintained machinery, the seeding/mulching of all exposed soil surfaces within two weeks from the final completion of site excavation, and the irrigation of the wetland and buffer areas to ensure plant community establishment. In addition, best management practices as identified within the erosion control plan prepared for this project site will be used during the entire construction phase to protect water quality. CONSTRUCTION SEQUENCE TASK APPROXIMATE DATE OF COMPLETION Initial onsite team meeting to define final construction steps September 30, 2001 and oroiect team tasks. Onsite marking of wetland creation area and outer buffer October 15, 2001 boundaries. Placement of protective silt fencing and other erosion orotections as needed. Plantina of wetland and buffer areas. Final construction reoort PROJECT MONITORING November 15, 2001 November 30, 2001 Evendell-22 Wetland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 33 Following the successful completion _of the proposed compensatory mitigation plan a five-year monitoring and evaluation program will be undertaken. The purpose of this program is to assure the success of the selected mitigation as measured by an established set of performance criteria (see above). This monitoring will also provide valuable information on the effectiveness of mitigation procedures. STANDARDS OF SUCCESS Vegetation Sampling Methodology and Monitoring Schedule Permanent vegetation sampling plots will be located within each planting community in areas representative of the communities being sampled. These sampling plots will be located along specific transects and at stationary identified points. Observations and measurements will be recorded for all plant species in order of dominance based on the relative percent cover for each species within the various vegetation strata. Sampling for tree and shrub species will be completed in 30-foot radius sampling plots. Stratified methods will be used to increase the precision of sampling data while also maintaining elements necessary for statistical inferences. ,, The evaluation of the success of the enhancement program will be based on the expected cover percentages to be defined within the final compensatory mitigation plan and the selected 80% survival rate at the end of the fifth growing season following initial planting. The percent of aerial cover and the percent survival rate will be based on combined counts of existing and planted species during vegetation monitoring. Sample location will be shown on the design and the "record drawings" plans, and will correspond to identified photo points. Trees and shrubs will be visually evaluated to determine the rate of survivorship, health, and vigor of each plant. The categories to be used will include live, stressed, tip dieback, basal sprouts. not found, apparently dead, and dead. Vegetation ll/lonitoring 1. Upon the completion. of initial planting and as a part of each monitoring period the project biologist will count the number of plants which were planted within the wetland and buffer areas. -Plants will be identified to species and observations of general plant condition (i.e., plant health, amount of new growth) are to be recorded for each plant. 2. At identified sample plots within the created wetland and the enhanced buffer areas the project biologist will. determine percent coverage of vegetation using the Canopy Coverage Method sampling (0.25 m2 plot frame) procedure for emergent species and by using the Line-intercept Method sampling procedure for the scrub/shrub and sapling tree species. 3. Within the entire mitigation area the project biologist will count the number of undesirable invasive plants and estimate the aerial coverage (as if the observer Evendell-23 Wetland/Wildlife Report -00062 ' 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 34 were looking straight down from above) of these invasive plants. Undesirable plants include blackberries, Scot's broom, tansy ragwort, reed canarygrass, and other such plants listed in the Washington State Noxious Weed List 4. Within the entire mitigation area the project biologist will count the number of desirable "volunteer'' plants and estimate the aerial coverage of these plants. 5. The project biologist will take photographs that show the entire mitigation area. During the five-year monitoring period photos will be taken in the same direction and at the same location to provide a series of photos. These photos will show plant growth, plant species, and plant coverage. 6. Upon the completion of the initial project planting and upon the completion of each monitoring period the project biologist will prepare a report defining methods, observations, and results along with the date the observations were completed. Each report will be sent to King County wetlands staff. 7. The monitoring schedule is defined as: A. At the completion of initial project planting. This report will include a ·record drawing" defining the species used, locations, and general site conditions. This report will also include a "lessons learned" section to assist in future monitoring and final project assessment. This "record drawing' and report will be provided to the County within two weeks after the completion of onsite planting. B. Twice a year for years one through three following the completion of initial onsite planting. For each monitoring year, onsite monitoring will be completed once early in the growing season (late March to mid-April) and once again near the end of the growing season (mid-September). For each onsite monitoring activity a report will be prepared and provided to the County within two weeks after the completion of onsite monitoring. C. Once a year for years four and five following the completion of initial onsite planting. For each monitoring year, onsite monitoring will be completed once near the end of the growing season (mid-September). A report will be prepared and provided to the County within two weeks after the completion of onsite monitoring. MONITORING YEAR YEAR-1 YEAR-2 YEAR-3 Vegetation Monitoring Sequencing VEGETATION MONITORING On or about Aoril 15, 2002 on or about Sept. 15, 2002 On or about Acri! 15, 2003 on or about Sept. 15 2003 On or about Acri! 15. 2004 SUBMITTAL OF MONITORING REPORT Report due Mav 25, 2002 Reoort due Oct. 15. 2002 Report due Mav 25, 2003 Reoort due Oct. 15, 2003 Reoort due Mav 15 2004 Evendell • 24 Wetland/Wildlife Report· 00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 35 on or about Sept. 15. 2004 Reoort due Oct. 15. 2004 YEAR-4 on or about Sept. 15, 2005 Report due Oct. 15, 2005 YEAR-5 on or about Seo!. 15, 2006 Reoort due Oct. 15, 2006 The last monitoring report dated October 15, 2006 will include notification to the County biologist that the monitoring program has concluded and that County review and site inspection is required for project analysis and release of the financial guarantee. This final report will also include a . "lessons learned" section to assist and final project assessment and to potentially assist in the evaluation other mitigation projects. WILDLIFE OBSERVATIONS Observations of wildlife will coincide with the onsite activities undertaken as part of the Vegetation Monitoring Program. The onsite team will document the extent of bird species abundance, site utilization, nesting and feeding activities, and species diversity. In addition, documentation of terrestrial and aquatic reptiles, amphibians, and mammals observable without trapping will also be documented. Wildlife observations will be documented within the Vegetation Monitoring Reports noted above. VEGETATION MAINTENANCE PLAN Maintenance of the enhanced wetland and buffer plant communities may be required to assure the long-term health and welfare of the wetland's and buffer's environmental functions. Such maintenance would be identified during the monitoring period and undertaken only following discussion and coordination with King County wetland staff. The overall objective is to establish undisturbed plant communities that do not require maintenance. · Activities may include, but are not limited to, the removal of invasive non-native vegetation and the irrigation of selected areas. Established maintenance activities include the removal of any trash within the wetland and buffer. Temporary irrigation will be established (if necessary) to ensure one-inch of water from June through September of the first year following installation of the plantings. The need for temporary irrigation of these areas during subsequent years will be defined during the spring monitoring period. REMOVAL OF INVASIVE NON-NATIVE VEGETATION As a contingency, should the removal of invasive non-native vegetation become necessary, the project proponent will contact King County wetland staff to establish and define specific actions to be taken. Resultant contingency plan activities will be implemented when the ongoing vegetation monitoring program indicates that plants listed in the Washington State Noxious Weed List, blackberries, Scot's broom, tansy ragwort, or reed canarygrass are becoming dominant in the community. Evendell-25 Welland/Wildlife Report -00062 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 36 CONTINGENCY PLAN As a contingency, should the proposed compensatory plan fail to meet the performance criteria, the project proponent will undertake required remedial actions. Where plant survival is the failing component, the project proponent will replant and assure the success of this second planting which would be held to the same standard of success as measured by threshold criteria and monitoring processes. Should additional remedial actions be required, the project proponent will meet with King County wetland staff to establish and define actions to be taken to meet the desired goal of this program. PLANTING NOTES All plant materials shall be native to the Puget Sound Region. The onsite biologist shall inspect plant materials to assure the appropriate plant schedule and plant characteristics are met. The project proponent shall warrant that all plants will remain alive and healthy for a period of one-year following completion of planting activities. The project proponent shall replace all dead and unhealthy plants with plants of the same specifications. FINANCIAL GUARANTEE Financial guarantee will be provided for this project to ensure project completion and performance: This guarantee is defined using the standard King County Bond Quantity Worksheet (Appendix B). Evendell-26 WetlandNVildlife Report -00062 05/10/2004 15:08 2535390514 C=flAIBBTA 1r YECll=llN@ll.,@~8~$ SOUNDBUILT HOMES I t.s I "1 i I I I ST::;.!' ' l I vi/ SE/ 131ST / ST <Cl ~ ::1,1 . /' J 13lST i.., / <C ;,,.• I : PL Ul• ...:/ SE 132ND,_;E 132ND ~ f ni SE l PL /a ~ ; ;C ' C\J ;l;; c:: II J C-, I-" " .... <c ~:: ~, ~ SE 134TH ;e ST :c, ,.... I ::/ /~ ~! ST/ ,'~ .... , l i . ~6DOO / ::,:! /;51 ~~L ; ,....1SE LIBERTY ~ I HS I i I Lu V')' figuire 'ii Sfite Vecn1n16ey PAGE 38 05/10/2004 15:08 2535390514 ,; . ··.~ .. 'I ~SC.---*lli' i, .............. -1 '?-·-.... -· ......... ' \ IHIA~DTA¥ Tf!CHINIOlla@GHli:$ ', ' SOUNDBUILT HOMES PAGE 39 \ ' .,,., • . .;,,..,~ . I;!.. ,I, • ' • ..,,. __ ...... .. t -, ·~ -';,--- \ ·~ . '· __ ..._~.-- .- .. ~twe ------.. \,,,<-.••. ' --~ t ·? ,,. j IRgure 2 NWD ReSOl/!!i'C<e Mappili'llg 05/10/2004 15:08 2535390514 I I ! I I I I I I I f ---· ll=BA~DT.A'iF TEeHN@lbOGIES I I SOUNDBUILT HOMES PAGE 40 Fig11.B6"e 3 PHS Resource Mappiing • 05/10/2004 15:08 2535391:1514 .. ..... It .. • • • ~. o, tHI.AB BT AT TECHNOLOGHES • .. .. ... IS Iii', 111"-Q., .... • • .. SOUNDBUILT HOMES .. • ---- D'" 0 • a _DI D" -.;i:, .. • " • . .. ·Q •• :~ ·:. ~..,_:ir--:-'·\' ··;.:.;: .• . _.,.. :'.'.~-; _:-.:' --- ,: ; .. , '•';- ... a• ID 111 oaR .. •· • .. • • • tt; .. • a •• • • • • . .. . ··o:· ]:"a• ~f .· : aa·ao\~ • • a •. • • 0 0 D Fngl!.llli'e 4 D • Soil Mapping PAGE 41 B5/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 42 REFERENCE LIST Adamus, P.R., E.J. Clairain Jr., RD. Smith, and R.E. Young. 1987. Wetland Evaluation Technique (WET); Volume II: Methodology, Operational Draft Technical Report Y-87, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Office of Biological Services, U.S. Fish and Wildlife Service, U.S. Department of the Interior, FWS/OBS-79/31. Environmental Laboratory. 1987. "Corps of Engineers Wetlands Delineation Manual," Technical Report Y-87-1, US army Engineer Waterways Experiment Station, Vicksburg, Miss. Hitchcock, C.L., A. Cronquist. 1977. Flora of the Pacific Northwest. University of Washington Press. Seattle, Washington. Horner, R.R. and K.J. Raedeke. 1989. Guide for Wetland Mitigation Project Monitoring. Washington State Department of Transportation. contract number GC8286, task 6. King County Department of Natural Resources. 1993. DRAFT Wildlife Management in King County: Issue Paper. Mikol, S.A. 1980. Field Guidelines for Using Transects to Sample Nongame Bird Populations. U.S. Fish and Wildlife Service publication FWS/OBS -80/58. Reppert, R.T., W. Sigleo, E. Stakhiv, L. Messman, and C. Meyers. 1979. Wetland Values -Concepts and Methods for Wetland Evaluation. Research Report 79-R1, U.S. Army Corps of Engineers, Institute for Water Resources, Fort Belvoir, Virginia. U.S. Department of Agriculture, Soils Conservation Service. Soils Survey of King County Area Washington, Nov. 1973. Washington State Department of Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Publication Number 96-94. Washington State Department of Fisheries, Catalog of Washington Streams and Salmon Utilization, Volume 1., 1975 Evendell -28 Welland/WIidiife Report -00062 05/10/2004 15:08 2535390514 .. ,_. .. SOUNDBUILT HOMES APPENDIX A FIELD DATA FORMS Evendell-29 Wetland/Wildlife Report -00062 PAGE 43 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 44 SAMPLEPLOT_S~P~1:...-~~~~~- DATAFORM Projed/Site Applicant/Owner: Investigator: ROUTINE WETLAND DETERMINATION (1987 COE WETLANDS DELINEATION MANUAL) ....;;;E.;,;ve::.:n.:.;:d::::e::.11 ____________________ Date: ...;;;M~~~M~i~ke:.;.:R~om~a~no~------------------County. ...!.!H:::ab::!it:!!:a~t .:,T,:::ec::::h::.:n:::o:::I :ii:i:::es::._ _________ -=------State: Have vegetation, soils, or hydrology been disturbed? Is the area a potential Problem area? YES YES Community ID: Transect 10: . Plot 10: (If needed. explain on reverse) 17 July 2000 Pierce Washington SP1 VEGETATION (Note those species observed to have morphological adaptations to watlands with an•) no 1--~ Plan• "--c1-S•""u"' ln'""n•or I 0o""'"a"' p1 .. nt Soe...i .. ., Stratum 10 r1;,...,0 r 1. 2. Acer macronhvilum Tree FACU 3. Sao. Corvlus comuta Shrub FACU 4. Rubus snectabllls Shrub FAC+ 5. Rubus nrocera Shrub FACU 8. Rubus lacinatus Shrub FACU- 7. P1eridlum anuilium Herb FACU 8. I Percent of Dominant species that are OBL, FACW, or 0% C (except FAC-). Include species noted (") as showing .Jrphological adaptations to wetlands --------------------------1 I Describe Morphological Adaptations: Remarks: Near nraded roadbed HYDROLOGY Recorded Data (Desatbe in Remarks): -stream, Lake, orTide Gage __ Aerial Photograph __ Other _!_ No Recorded Data Avallable FIELD OBSERVATIONS: Depth of Surface Water: O' Depth to Fn:e Water Pit: O • ' Depth to Saturated Sot1: o• Remarks: Deciduous forest Wetland Hydrology Indicators: -Inundated --Saturated in upper 12" -Water Marks Drift Lines Sediment Deposits Drainage Patterns in Wetlands -2L_ Oxidized Root Channels in Upper 12 • Water-stained Leaves -Local Soll Survey Data -Other {Explain In Remarlcs) '• 05/10/2004 15:08 2535390514 iap Unit Name: Alderwood gravelly sandy , a)(Onomy (Subgroup):Oystrie Entlc Ourochrepts Profile Description: Depth (inches) Horizon Matrix Color (Munsell Moist) 0-18 10 YR 313 Hydric Soll Indicators: Hlstosol ---Histic Epipedon ---Sulfldic Odor ___ Probable Aquic Moisture Regime ___ Reducing Conditions ___ Gleyed or Low Chroma Colors Remarlcs: 41d indicators of hydric soil NOT pntsent WETLAND DETERMINATION Hydrophytlc Vegetation Present? Hydric Soils Present? Wetland Hydrology Present? Remarks: WETLAND CRITERIA NOT MET YES' YES YES SOUNDBUILT HOMES PAGE 45 SAMPLE PLOT _S_P __ 1 _____ _ Drainage Class: · Field Observations Confirm Mapped Type Yes No Mottle Colors (Munsell Moist) Mottte Texture, Concretions None AbUndance/Contrast Rhizospheres, etc. None Gravelly loam Concretions ------High Organic Content in Surface Layer ___ Organic Streaking ___ Listed on Local Hydric Solis List ___ Listed on National Hydric Solis Ust ___ Other (Explain in Remarks} Is this Sampling Poin~ within a ~ WeUand? c::.,,; Area appears to drain well following seasonal stonn events •• 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 45 SAMPLE PLOT SP 2 --------- DAT AF ORM ROUTINE WEllAND DETERIVIINA TION . (1987 COE WETLANDS DELINEATION MAI\IUAL) Project/Site Applicant/Owner: ...;:;Ev;.;.e:;;n;,;:d.;:;e;;.11..,. _________________ Date: 17 July 2000 ~M.r .... M..:l;;;ke=R;.;..;;om=an;;,;o_,.. ______________ County: ..,Pa.,;i,;.erce~---- Investigator: ...;.;H;:;ab:;.;il;;;at;;...;.Te;;.;Ch=n.;:;ol"'OQl .. ·;;;es;_ _____________ State: Washington Have vegetation, soils, or hydrology been disturbed? Is the area a potential Problem area? (If needed. explain on reverse) YES M YES '(!!!! Community 10: Transect ID: Plot ID: SP2 VEGETATION (Note those species observed to have morphological adaptations to wetlands with an •1 Dn nfnant Pia"' "'-cles s or I D0 ... 1n""' Pia"' <>-~ies Stratum fndfcator 1. 2. Sao. Pooulus trichocama Shrub FAC 3. Carex obnunta Hert, OBL 4. Juncus effusus Herb FACW 5. 6. 7. 8. t Percent of Dominant spacies that are OBL, FACW, or 100% C (except FAC.). Include species noted (") as showing Jrphological adaptations to wetlands I Describe Morphological Adaptations: --------------------------; Remarks: . swale deoression on edve of homesite area HYDROLOGY Recorded Data (Describe in Remarks): -Stream, Lake, orTide Gage Aerial Photograph --Other ..,..,.._ X No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water. o· Depth to Free Water Pit: o • . -Depth to Saturated Soll: _o_·_ Remarks: Depr,assionional swala on i!f of cleared lnomesite . Nelll to slash pile and root ~and Hydrology Indicators: Inundated -Saturnted lri upper 12" Y-Water Marks -X-Drift Lines --Sediment Deposits ~ Drainage Pattems in Wetlands --Oxidized Root Channels in UJJPBr 12 • -Y-water-Stained Leaves = Local Soil survey Data Other (Explain In Remerks) 05/10/2004 15:08 2535390514 lap Unit Name: Alderwood gravelly sandy raxonomy (Subgroup):Oystnc Entic Ourochrepts Profile Description: Depth (inches) Horizon Matrix Color (Munsell Moist) 0-6 10 YR2/1 ~18 10 YR 4/1 Hydrlc Soil Indicators: Histosol ------Hlstic Eplpeclon Sulfldlc Odor ---_x__ Probable Aquic Moisture Regime Reducing Conditions ...,.,. __ X Gleyed or Low Chroma Colors --- Remarks: . ,eld indicators of hydric soil presem WETLAND DETERMINATION Hydrophytic Vegetation Present? Hydric Soils Present? Wetland Hydrology Present? Remarks: WETLAND CRITERIA MET NO NO NO SOUNDBUILT HOMES PAGE 47 SAMPLE PLOT SP 2 ---------D ra In age Class: Field Observations Confirm Mapped Type Yes No Mottle Colors (Munsell Moist) Mottle Texture, Concretions Abundance/Contrast Rhizospheres, etc. None None Gravelly loam 10YR3/2 PromJcommon Clay loam X Concretions -------High Organic Content in Surface Layer ___ Organic streaking ---Listed on Local Hydric Soils Lisi ---Listed on National Hydric Soils Ust Other (l:xplain in Remarks) --- Is this Sampling Point within a ~ Wetland? ~ Area appears to drain poorly following seasonal storm events 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 48 ·-·· SAMPLE PLOT SP 3 --------- DATA FORM ROUTINE WEll.AND DETERMINATION (1987 COE WETLAIIIDS DELINEATION MAI\IUAL) Projed/Site Applicant/Owner: EvendeD Date: ...;;,,-;,a,,.;.;..,,..----------------17 July 2000 Pierce Investigator: .. M""""r. ,..;;M.i_k ee,R:-=om ... a n_o-e-______________ County: -"H"'ab_itc:a:.:.t.;..T.;;.eeh __ n_ol .. og.,.l"'e-s ______________ State: Washington Have vegetation, soils, or hydrology been disturbed? Is the area a potential Problem area? (If needed, explain on reverse) YES 'NO YES NO Community ID: Transect ID: Plot ID: SP3 VEGETATION (Note those species observed to have morphologlcal adaptations to wetlands with an •1 Oomjn,on+ Dh•nt $NO"l"S SI""""" I I Dom•"&"' Dlant ~="'es Stn»um lnd1-or 1. 2. Sa1>. Alnus rubra Shrub FAC 3. Carex obnuma Herb OBL 4. Phalaris arundinacea Herb FACW 5. Salix Sltehensls Scrub FACW 6. 7. 8. j Percent of Dominant species that are OBL, FACW, or 100% C (except FAC-). Include species noted (") as showing ,rphological adaptations to wetlands --------------------------; I Describe Morphological Adaptations: Remarlc:s: swale depression on Beige of llomesite area HYDROLOGY Recorded Data (Describe in Remarks): ---Stream, Lake, or ride Gage --Aerial Photograph Other ---_!._ No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water: o· Depth to Free Water Pit: O " _ Depth to Saturated Soil: O" --- Remarfls: Depl9Ssionional swale on edge of cleared llomeslte ~and Hydrology Indicators: Inundated Saturated in upper 12" X Water Marks --;c-Drift Unes -Sediment Deposits --X-D,ainage Patterns In Wetlands -O>cidlzed Root Channels In Upper 12 • Jt Water.stained Leaves Local Sotl Survey Data -Other (Explain ln Remerb). > 05/10/2004 15:08 2535390514 ap Unit Name: Alderwood gravelly sandy , axonomy (Subgroup):Oystrlc Entic Ourochrepts Proflle Description: Depth Qnches) Horizon D-6 6-18 Hydric Son Indicators: Hislosol ------Histlc Epipedon Sulfidlc Odor --- Malrtx Color (Munsell Moist) 10 YR 212 10 YR 3/4 ---Probable Aquic Moisture Regime ---Reducing Conditions ---Gleyed or Low Chroma Colors Aqmarks: r ,eld Indicators or hydric soil not present WETLAND DETERMINATION Hydrophytic Vegetation Present? ~~ Hydrlc Soils Present? ~.,. weuand Hydrology Present? YES Remarks: WETLAND CRITERIA NOT llllET Sample plot on edge of defined wetland SOUNDBUILT HOMES PAGE 49 SAMPLE PLOT SP 3 Drainage C~la_ss_: ------- Field Observations Confinn Mapped Type Yes No Mottle Colora (Munsell Moist) MotUe Texture, Concretions None None Abundance/Contrast Rhlzospheres, etc. None Gravelly loam none gravelly .loam Concretions ---High Organic Content In Surface Layer ___ Organic Streaking ___ Listed on Local Hydric Soils list Listed on National Hydric Solis list ------other (Explain In Remarb) Is this Sampling Point within a @ Wetland? Area appears to drain well following seasonal stann events • 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 50 --SAMPLE PLOT SP 4 ------------- Projed/Site ApplicanUOwner: Investigator: DATA FORM ROUTINE WETLAND DETERMINATION (1987 COE WETLANDS DELINEATION MANUAL) Evendell Date: ~,.-;,~'-:,-----------------.....,M"'~"'llni"''-k e,,,,_;..;R .. o m;.;..;;;a ;..no...,... _____________ ~ County: ___ H_abi;;:';;:tat::..;.T .. ech=n .. o;;;logai;,;;es;;;,_ _____________ state: Have vegetation, soils, or hydrology been disturbed? Is the area a potentlal Problem area? YES NO YES NO Community ID: Transed ID: (If needed, explain on reverse) Plot ID: 17 July 2000 Pierce Washington SP4 VEGETATION (Note those species observed to haw morphotoglcal adaptations to wetlands with an •1 On ,1nant Dlant S"""'es ,,,...,.um . f""f,....nr I Do · · Plant "'necies """"'um 1. 2. Sap. Alnus rubra Shrub FAC 3. Carex obnuma Hero OBL 4. Phalaris arundinacea Herb FACW 5. 8. 7. 8. j Percent Of Dominant species that are OBL, FACW, or 100% ~ (except FAC-). Include species noted (") as showing ,rphologlcal adaptations to wetlands I Describe Morphological Adaptations: Remarks: swale depression on edae of homesilll! a111a HYDROLOGY Recorded Data (Describe in Remarks): -Stream, Lake, orTide Gage Aerial Photograph --Other X No Recorded Data Available FIELD OBSERVATIONS: Wetland Hydrology Indicators: -Inundated Saturated in upper 12· X Water Merits -X-Drift Unes Sediment Deposits '""icator ,r-Drainage Patterns in Wetlands -Oxidized Root Channels In Upper 12 ' Depth Of Surface Water: O' Depth to Free Water Pit: O • Depth to Saturated Soil: __ o· __ Remartts: Depressioniom,I swale on edge of cleared llomesite X Water-Stained Leaves -Local Soil Survey Data -Other (Explain In Remar!ts) • 05/10/2004 15:08 2535390514 lap Unit Name: Aldeiwood graveny sandy <'axonomy (Subgroup):DySlric Entic Durochrapts Profile Description: Depth (inches) Horizon Matrix Color (Munsell Moist) 0-8 6-18 H)'dric SoD Indicators: ___ Histosol ___ Histic Epipedon ___ Sullidic Odor 10 YR 211 10 YR 411 ..;.:X__ Probable Aquic Moisture Regime ___ Reducing Conditions ,JC Gleyed or Low Chroma Colors Remarks: • .eld indicators of hydric soil present WETLAND DETERMINATION H)'droph)ltlc Vegetation Present? H)'dric Soils Present? Wetland Hydrology Present? Remarlts: WETLANID CRITERIA MET NO NO NO SOUNDBUILT HOMES PAGE 51 SAMPLE PLOT SP 4 ,.,------.:....._ ....... __ Drainage Class: Fleld Observations Conflnn Mapped Type Yes No Mottle Colors (Munsell Moist) Mottle Te,iture. Concretions Abundance/Contrast Rhizospheres, etc. None None Gravelly loam 10YR 3/2 Prom./common Clay loam X Concretions """"-----High Organic Content In Surface Layer ___ Organic Streaking ___ Listed on Local Hydrlc Soils List ___ Listed on National Hydric Soils List -----Other (Explain in Remarks) Is this Sampling Point within a ~ Wetland? L/ Area appears to drain poorfy following se4sonal storm events 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 52 ·sAMPLE PLOT SPS -=,;..;;. ______ _ Project/Site Applicant/Owner. Investigator. DATA FORM ROUTINE WETLAND DETERMINATION (1987 COE WETLANDS DEUNEA 110N MANUAL) Evendell Date: -===:.-.----------------_M;:;:,:.;r · ,.,M;::l :::ke;;,:R~o:;:m.;.;;:;a n::.:O;.,...--------------County: Habnat Technol ies State: ~=~=~------=,-.,..--- Have vegetation, soils. or hydrology been disturbed? Is the area a potential Problem area? CommunHy ID: Transect 10: (If needed, explain on reverse) Plot ID: 17 July 2000 Pierce Washington SP6 VEGETATION (Note those species observed to have morphological adaptations to wetlands with an •1 nft njnant C>necles (n .. lMlor I Do-inftM l:llant S-"'0 " -· -· fnd;c..tnr 1. 2. Alnus rubra Tree FAC 3. 4. 5. Rubus "'"C8ra Shrub FACU 8. Rubus laclnatus Shrub FACU· 7. Ptericlium aaumum Herb FACU 8. . J Petcent of Dominant species that are OBL, FACW, or 25% \C (except FAC-). Include species noted (") as showing Jrphological adaptations to wetlands -------------------------1 I Describe Morphological Adaptations: Remarks: Cleared homesite area HYDROLOGY Recorded Data (Describe In Remarks): -stream, Lake, orTide Gage __ Aerial Photograph __ Other _2L No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water: o· Depth to Free Water Pit: 0 • Depth to Saturated Son: o• -Remarks: Deciduous forest Welland Hydrology Indicators: -Inundated Saturated in upper 12' . __ Water Marks Drill Lines Sediment Deposils Drainage Pattems in Wetlands Oxidized Root Channels In Upper 12 • X-Water-Stained Leaves Local Soll Survey Data -Other (Explain in Remarks) 05/10/2004 15:08 2535390514 ap Unit Name: Afderwood gravelly sandy i'axonomy (Subgroup):Oystric Entlc Ourochrepts Profile Description: Depth (inches) Horizon 0-8 Matrix Color (Munsell Moist) 10YR2/2 8-18 10YR2/2 Hydric Soil Indicators: ___ Histosol ___ Histic Epipedon ___ Sullldic Odor ___ Probable Aquic Moisture Regime ---Reducing Condttions ___ Gleyed or Low Chroma Colors ~emarlt!I: .-meld indicators of hydric soil NOT present WETLAND DETERMINATION Hydrophytic Vegetation Present? Hydric Soils Present? Wetland Hydrology Present? Remarks: WETLAND CRITERIA NOT MET YES~ YES YES NO SOUNDBUILT HOMES PAGE 53 SAMPLE PLOT SP& ~---------Drainage Class: Field Observations Confirm Mapped Type Yes No Mottle Colors (Munsell Moist) Mottle Texture. Concretions Abundance/Contrast Rhizospheres, etc. None None Gravelly loam 10YR5/8 FainVuncommon loam Concretions ------High Organic Content In Surface Layer ___ Organic Streaking ---Listed on Local Hyd!ic Soils List ___ Listed on National Hydric Soils List ---Other (Explain In Remarks) Is this Sampling Point within a ~ Wetland? ~ Area appears to drain well following seasonal storm events 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 54 SAMPLE PLOT SP 8 _;;;;...;; ______ _ DATA FORM ROUTINE WETLAND DETeRMINA TION 11987 COE WETLANDS DELINEATION MANUAL) Project/Site Applicant/Owner: _E;:,,V::..:B:,:nd:;;.e;;;l;.,I -----------------Date: 17 July 2000 .... M~r-,..;,M .. l::.;.ke;;,;..;R.;;;om=an""o'---------------County: . _P_i_erce _____ _ Investigator: ...;H:.:a::b::::il::.at!..T:..:e:::ch:.::no:.:::.::I ::cies=--------------State: Washington Have vegetation, soils, or hydrology been disturbed? Is the area a potential Problem area? (If needed, explain on reverse) YES YES Community 10: Transed ID: Plot ID: SP 8 VEGETATION (Note those species observed to have morphological adaptations to wetlands WitfJ an •1 Domin•·• Plan• s•~cies ""'ratu-ncfl~ ... ft, I Oo • p1.n1 "'-cie" s•-·-'·"'cator 1. 2. Sao. Pnnuius trichocarna Shrub FAC 3. 4. Juncus effusus Herb FACW 5. Rubus laciniatus Shrub FACU- 6. 7. 8. I Percent of Dominant species that are OBL., FACW, or 66% c (except FAC.). Include species noted (*) as showing ,rphological adaptations to wetlands --------------------------1 I Describe Morphological Adaptations: Remarks: Sl"'ht deoression on edae of homeslte area HYDROLOGY Recorded Data (Desaibe in Remarlls): -Stream, Lake, orTide Gage __ Aerial Photograph __ Other . X No Recorded Data Available FIELD OBSERVATIONS: Depth of Surface Water: o· Depth to Free Water Pit O • Depth to satumted Soil: o• , -Remarks: Slight depression on edge of cleared homeslle Next to slaSh pile and root ball weuand Hydrology Indicators: -Inundated Saturated in upper 12" X-Water Maru Drift Unes Sediment Deposits Drainage Patterns in Wetlands OJdd~ed Root Channels in Upper 12 • X-Water-Stained Leaves Local Soll Sun,ey Data Other (Ellplaln in Remaru) 05/10/2004 15:08 2535390514 9P Unit Name: Aldenvood gravelly sandy • axonomy (Subgroup):Oystric Entic Durochrepts Profile Description: Depth (inches) Horil:on Matrix Color (Munsell Moist) 0-4 10YR3/2 8-18 Hydric Soil Indicators: Histosof --Hlsllc Epipedon Sulfidic Odor -- 10 YR 413 --Probable Aqulc Moisture Regime --Reducing Conditions --Gleyed or Low Chroma Colors "1&_marks: .Id indicators of hydric soil NOT present wen.AND DETERMINATION Hydrophytic Vegetation Present? Hydric Soils Present? Wetland Hydrology Present? Remarks: WETLAND CRITERIA NOT MET SOUNDBUILT HOMES PAGE 55 SAMPLE PLOT SP& Drainage C.:=:l~ass".'."'"": ------- Freid Observations Confinn Mapped Type Yes No MotUe Colors (Munsell Moist) Mottle Texture, Concretions Abundance/Contrast Rhizospheres, etc. None None None Gravelly loam none loam Concretions ------High Organic Content in Sulfaca Layer Organic streaking ---Listed on Local Hydric Soils List Listed on National Hydric Soils List ---other (Explain in Remar11S) Is this Sampling Point within a ~ Watland? \..J Area appears to drain well following seasonal stonn events 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 55 SAMPLE PLOT SP12 --------- Project/Sile Applicant/Owner: Investigator. DAT AF ORM ROUTINE WETLAND DETERMINATION (1987 COE WETLANDS DELINEATION MANUAL) Evendell Date: ~~-==--:------------------· ~M ... r.~M":"i~ke-=--R..,o_m_a~no....,. ______________ County: _...H ... abit""· .. at ...... T ... ech ...... n ... o_lOQ...._le ... s ______________ state: Have vegetation, soils, or hydrology been disturbed? Is the area a potential Problem area? YES~ YES @Ji) Commun~y ID: Transect ID: (If needed, explain on reverse) Plot ID: 17 Juty2000 Pierce Washington SP12 VEGETATION (Note those species observed to liava morphological adaptations to wetlands with an ") D . PJ:>nt Sner.i«~ 1n,tj<,:,tnr . l nnm1nant Plant ~-,,.es Slmtnm lndl.....tnr "' 1. 2. Alnus rubra Tree FAC 3. 4. 5. Rubus nmcera Shrub FACU 6. Rubus lacinatus Shrub FACU- 7. Pteridium aauifium Herb FACU 8. I Percent or Dominant speC!es that are OBL, FACW, or 25% c (except FAC-). Include species noted (") as shoWlng Jrphological adaptations to wetlands --------------------------i I Describe Morphological Adaptations: Remarks: Cleared homeslte area HYDROLOGY Recorded Data (Describe in Remarks): -Stream, Lake, or Tide Gage __ Aerial Photograph other 2._'""N.,..o""'R""ecorded Data AvaUable FIELD OBSERVATIONS: Depth of Surface Water. o· Depth to Free Water Pit O • Depth to saturated son: _o __ ·_ Remarb: Deciduous forest Wetland Hydrology Indicators: -Inundated -Saturated In upper 12" -Water Mar11s Drift Lines -Sediment Deposits -Drainage Patterns In Wetlands . -Oxidized Root ChannelS in Upper 12 • -Water-Stained Leaves -Local Soll Suniey Dabt -Other (Explain in Remarks) 05/10/2004 15:08 2535390514 ap Unit Name: Alderwood gravelly sandy laxonomy {Subgroup):Dystric Entic Durochrepts Profile Description: Depth (inches) Horizon Matrb( Color (Munsell Moist) 0-4 10YR 3/2 4-18 10 YR 413 Hydric Soil Indicators: Hlstosol ------Histic Epipedon Sulfidic Odor ------Probable A.quic Moisture Regime ---Reducing Conditions ___ Gleyed orlowChroma Colors Remarks: , .eld indicators of hydric soil NOT present WETLAND DETERMINATION Hydrophytic Vegetation Present? Hydric Soils Present? Wetland Hydrology Present? Remarks: WETLAND CRITERIA NOT 11/lET YES~ YES . YES 111.0 SOUNDBUILT HOMES PAGE 57 ... .,.· SAMPLE PLOT ,,,s ... P_1;;;;2 _____ _ Drainage Class: Field Observations Confirm Mapped Type Yes No Mottle Colors (Munsell Moist) Mottle Texture. Concretions None None Abundance/Contrast Rhizospheres, etc. None Gravelly loam None loam Concretions ------High Oiganic Content in Surface Layer ---Organic Streaking Usted on Local Hydric Solis Ust ---Listed on National H)dric sous List other (Explaln in Remarils) --- Is this Sampling Point within a ~ Wettand? ~ Area appears to drain well followlng seasonal stonn events • Herbs and Groundcovsrs I !lc.tentlf1c NUUi! CtllmMn Ma.me Unit Pric1 · Qtv U'nit: P~ici Qtv Unit Prio40tv 4" PClt 1 cra.llon Se«.ds/aa. Achlllea adlletol!um Yarr<>lf • ll,S2 AD.aohalis urnarltac Pearlv everlaat,11 , s ?.69 A:rctoatanhVJo,, uva-u JUnniltinnick $. l.l? • 33.~8 AnJnCUB dJ gj CUI/ Qoat • s bea:rd s 13 .S4 s 33,28 C.Hba oalustr1Y tie.Zeh fM.!:'J.gold $ 14. l9 s .o, 08 Ulc~tra formosa Bleed.Ina heai,t • 2.27 s ll.22 S 122. 88 R»Jlob1um aagustJlol Vireweed ~ U,44 Praaa.rJi111 ch1lot!J11ij.t Coa.et atra.Wbe~ $ 2,27 • S7,60 a.um macronhvJJum B.ia-leilf' avena s 2.27 ~ 51. 20 Hdracleum laz:tatum cow narsniu s l..45 hvllu10 tenujn, Pacific waterle.tf A J • .l? 4 11,91 liJnns:-.a boNal :ls Tlf!nUower s 2.27 • 143. 46 .LUDJtt\.ld llOl•rnb11JluS Sti:r-leat' lu1:>ine • 6,72 LYs.tah1~C'llJ. •tnar1ca~u Skunk cabbage s 13 .a, Na1antb.ttmum dil-atatr Wild lily or the •• 2.l7 lfJmulus n'11Ctat:us Yellciv monkev tl § l.27 $ llS.00 INOsot:JJJ lUa S'nlall foruet-me-not 8 2,. ea O..naatlul sa:rme.ntasa tl&te.t' DUSl!!IV ll 12 .58 s 44.80 OamarbJza ahJl0ttJ1si• !ilfa.et cic:ely .!I 44,·. BO Qx-a11B Ol:'80'.t»il 9'o-cd.-sot-rel $ 2.27 $ 89.GO Petasitep lrigiduu Coltafoot • 13.22 l'ol naniaaria i.a.tu 1s thumb Pot~nt11ls tn.itioosa Bush DOt:.ett.tilla SD.ilacins stalJata solc1n0n's Star ~ 2.27 Sta.c1rtna ccolevae area.t beitonv S 102,40 r<t!lJma aroncUllor• P'ringecup 4 lEL40 7Jarella trJroJiata foa•1Uower • 143,46 Tol~Jea rnen•JesJl Pi09rtu-baak ola.nt & 2.:t7 $ 102,40 VJol• <Jlaball.a Btreatn \riolat. $ 2.27 W<!b-llolldQ....,tityW-..iRnal,ldll Sansll:lve Arttas Bond Quantity wor/tsheet • Qtv 'total Coat • - s - s - g - s - $ . • . s . $ - s . ii - $ - s - A - $ . 5 . s . • - s . s - $ -• . s -• - $ . $ - $ - PoG• 4 Augu,t a, 1998 Q U1 -.... ,_. Q -.... "' Q Q A ,_. U1 Q CD "' U1 w U1 w <D Q U1 ,_. A I H r -< ! ~ ~ "' "' 05/10/2004 15:08 2535390514 SOUNDBUILT HOMES PAGE 58 ·-.~· APPENDIX B KING COUNTY BOND QUANTITY WORKSHEET Evendell-30 Wetland/Wildlife Report • 00062 -mu KilJgCcrwuy Oepuimec• afOtrclopn:i~t md l!nri.onmenr.d Su,ice, VOO 01..uldale AWAl:lc S0uthwts1 Rttttxm. WA taO:SS...1119 D<ltili //2--1/0L AppendixE: Bond Quantity Worksheet for Sensitive Area Mitigations l'rojoct Name, e:,,b/V/. I/ ~rojaot ~81'1 r.o~atiaa.1 Coutaet lfamo, Address, l'SJUl'.I' MA'l'BlltAJ.S , I I J»luc Hl.t•dmJ pr1c1111 Jaolude labor, 1MealJatJt3n, con~ai:::ton' mat'ho and aall!'& tu, but dOll't: include dsli~ry. (1:281 ot •hoJ,t1ule plar naas ScientU!c lla111e Coa:oum. Halite Unit Pric twv unit Pric Otv Gnit Pric Qtv CJnit. Pr.le Qty Tota:i. 4'll not l aallon l aallon '5 aallcn ~oat. Ab!es ,.....&ndi.•• "'""'and fir Acsr nracro»bYllum big leaf maple $ IJ, 54 ~ . AJnus rubr• sted alder ' l3 ,2l • . Ar'butua areai.!esjj Pa.citlc mad:rone s 14, 50 • . BetuJa. aantn'-J.te:r11 naner bJ.:rc:b s 13 ,23 $ . ""A Pr11.Jt1nus 1.at.it'olia Ore<1on ash s 13 ,22 s 2J.Sl ., -/. ~// //} • "17 ~ .(T) .?(~ic&a at~che~sis• Sitka Ul'lruce. ! ll .54 $ 24,lS ti 5.oo 1.(7 ~ '100 · Ocl PJ.JJUB COJ1torta* Sh.ore nine /J 13.54 $ 24 .15 " . PJnus mont1aola• Heste~n white cine s 13 .S4 • 24. lS s . Pom.olus t:remuloide• Miattir,,q ut1en $ 24.lS $ . »'ooulu• trtchocarPllil black cottonwood s ll .54 s 21.Sl s . PrwtLlB emanT.tn&ta bitter chsrrv $ 13.54 s . »seudotauga llMn~Jesf llnltnlae fir 8 L3 .SC $ 2j_5i s 44, 74 $ . 7axus brevjfolia• Pacific vsw s . >f Tbuja ,:,J.f(:',aca• M!tStern. r!!d. ceda s ll .54 s 21. 51 s 44. 74 7.n ii ')(' I i./ • •w rsuoa haterop.11ylla• weatol:'n hemlock $ lJ .54 ~ :Zl.82 $ 44.14 s . All Dlaut l)rJt"ss are frot1t. Youreh Corner Nu:rseri~s. Sound Native .Pl.m.t:s, storm Lake OroQi6ira. and Wabash Natives (contat and Abund'c1Dt LJ~e and Frostv Holl()W (teedsJ. I I I I I I ' WQI). ElofidQuan~tyWorbheet:Ai.t .xbl Sensitive Areas Bond Quantity WOl'lt'Shfft Pagel August 8, 1998 • CT) U1 '-.... CS) '- N CS) CS) "' .... U1 <S) ro N U1 w UJ CJ cD CS) U1 .... A § g C H r::; a { ffl ·. en -u ~ UJ cD SHRUBS U'nit Price unit Price ttni t Price Sclent.Hic Name C'ob'lllOn Na.me 4" Dot QtV 1 O"&llon QtV ::i aa11on Acu clrcinatum v.lne maple • l3.S4 s 23.Sl IL1!elaaahJ•r ala!foli aervlt:eber-rv s 13 .54 $ 23.92 Berberia a-41/oltum tall Oregon orace • 14.15 BQrberjs ner'll'Claa short ~...,.en ara1 e. s ll. 80 comas st"olo.oi tera red~o1ier dom.ioo, $ 13.22 in s 33.51 ('(J1"VJUS COl'llUta haaelnut • 13 .54 • al.s1 l".rataearJa douqla&1i blaok havthom s lJ.32 s .23.Sl Gau1ther1a ahallaa aal.al $ l. 89 !1. 13.9, Bolodiscus djecolo~ ocean -ra.v 9 l3 .54 s 2l.5L lio..aJ.ca.ra lavolUC"ra.ta black twin.berry s ll.54 Z.CI • 32.87 Mvrlce aa.le aweetgale r-.1ori41lSJr; horrJ.dus Devil's c:il\lb s 1J. a, • 24 .ls Qhlladal""us le~isli mock or"'""e s ll.54 s 32,87 Plw1111aaQl"ffUS CaDjtattJ Pacific ninebark s 13.:23 .., " $ 2l ,Sl Pru.qua viia1a1.taa ~oke cher%Y Pvn,s ~usca we.tern trabu,,.", • 13. l2 & 23.51 Rbumua JJursb.J a.ca CLISCU& $ u.n 4 23.51 ~ f>lmtli:IOJJ At.e-"·•lJWI PedUc rhcidcd•ndrllil s u.19 ~fbfts braeeeoeum stink: currant ~ 13.22 IUbes lacustre nt"icklv currant s 13 .8! Rlbes s~1.neu:m r~d-tlowQring crurrant s ll. 86 Rosa ........,""Ca "'"a Nood roae • lJ .34 s 2.4 , 15 Roa.t nutkana Bootka rose $ !l .54 $ 21.51. Ros.II Di•ooa-a clustered rose • ll,S4 e 22,87 lt1.1lN.r,1 leucoderm1s black rasobe:t>YV Rubus ...... rv.itlorua tbitllblehen,> .; ll , .S4 Rubus .meatab.llJs salt11onberrv s 13.22 1~ s 23.51 SalJx aevel"'J.4lta GeYer winow • 13 .22 $ 22.B7 saJtx hookeriaoa .l:lookar•s wil.lo'lf .. 12.91 $ 22,87 salJx las1Mcfra Pacitio willow • n.n • 2~. 87 Sa1Ja •coul~rlana S-cauler willow saljx sttchausls Sitka willow $ 13.22 1_ 0 • 22.87 S1mbucus racearosa red eld:erber-~ • 13.54 • ;13,51 Sorbus s1tcb.8ZJsJa Caacad~ mountain ash ~b.o~lcarntla albu• enowberty I • 13.23 -• 23.51 vaoct.ajt.Jtll ovatum eveP'Plre&tt huckleber.....u ~ 13.8' vacoJnJum osrvJtolJu nd hUcklebe~ I $ 2.91 $ 15.4'7 w•b-B<>ndQ"""til'IW-Anal.>hi Sensitlva Areas Bond Quantity worhhset Total lltY Othe:r ntv e.:iat. s . $ . • - $ . $ ll]Q. 7{' s . • . s - ; . s /ff'7-l/'0 $ - s . s . ,:-$ u 10-W 5 . $ . $ . • . ~ . $ - $ . • -• . $ . • . $ . ~ • u70 -z,. s . $ . a -• . $ ui:-,./Jr, s . ~ . s . $ . a . Pagel Augu;t a, 1999 • co lJl ..__ .... co ..... N co co "' .... (JI co CD N (JI w (JI w u, co (JI .... "' § ~ H r .... I . D I, ffl en ;g fj1 ()'1 co Seelaes and Rushe• I Scientilic Name oomu:m Mam.ei Unit Pric Qtv ll'nit Pric~otv Onl t Pric 411 nnt saeds/oz. 2 '10llon C'areJt aomosa Br.1.stlv sedae s 1.32 CSt'ex lent.tcular.ts Sbor& eel'lne $ 1.ll C'arex l ~ .... ··0 •uai Lvnaby BtMlne • 1.32 Carex ob.rUJi:,ta SlOUnh BddCJ~ s l.l2 s l!L20 Car«x rostrata (utrJ B&ake-d s e:dge $ 1.12 c..ux Bt1Data. Sa.Wb&a>i: seaae • 1.32 BleOCIUlrts actcu1ar1 solkerueb Bleochar1a »aluat.r1• CMmon Spik:erush $ l.32 -J\uJous a~Wldnatus 'l'a~ered rush s l.32 J\Jn(!Us art1aulatus .Jointed n1111h . ..tlmtnw &f"ct.raiu•lva.r. p.:,,dt Bott. rush $ 1,32 J'u.tiou• a.t1BJ~ol1us Dac'n'Jer leaf :ruab s 1.32 Juncus t'l1nlllMr J s Pointed rush s I.06 St!j r-nrn11 i!IICUtua ltardsts~ bulrush $ l.3J $ 23.04 Salrnua marittmus e&lt.,..rsh bulrusl s 1.n &aJ..-nua 111.icroearnua sr.au -ft'UJ ted tiul s 1, 32 Grasses Scientitic H~e t'Off'JnC.n Nam.e Ohit Pric Otv Unit Pric1 Qtv unit PrJ.01 4" got .8eeda/o.a. 2 aallon Alooecurus deduaJJs Sho:tt.-awn fo.)(tai AloDecurwr ae.lllculzu Wati,r foxtail s LOO 8aaltmi&ml1s sYz..1gach1J Au:lertcan alo~ang1 • 1.~o . a J .04 Cal.t1rruun"n&t1e c:anadana1 Bl~e1oillt reedr't'raaa Cfona lat.ito.J.la l(cod reed lJeB~hA111tist• aaeBDlto TU.fted bair9~ass s 1·. 06 s 9.60 Bl y,-,w, alauoua Blue wiJ.-....,a • 1., 36 Pescuca JdabCensJe Id.a.ha t•scue: /; 3.52 VsBtuc•'rubra va~. r Sled feScue $ 4.79 Gltmeria boreaJJg (o H'ortb.arn m.annaoraaa • 1.60 OlvcerJa •liu:a Tall mal'maora.., I $ 1,45 ~ l.60 PanJ.cwa oct:.1da1:1tale He:stern 1,1,anicaaTa.sa l'erns Sa:leacJ.Ltc Name CCCilllcm flame Unit Pric Otv U'ili t 13:ri C Qty Unit Pric 4n 1'0t l aallon 2 dallon Atb•~llllll tlllll•f•mJn lady fern ! l3, 86 Sl•chnum saicaat deer fe:rn $ ll ,U Drtn:JnterJ.s ~Ba abield tern < 13 .:it Polvstlallwlr l!IWlltum \Nteterh sword tern s 11.aG Nt•ridlum anu11JaJ1n bracken wob-BandQU11nll~Fl111l.idt Sensruve Areas Bond Quantity wol'ICrllleet Otv Otv Total Ot:her coat • . $ . • . • . • . s . $ . s . s . s . s . s . $ . s . $ . Qtv Qtv Total .,., .. $ . • . $ - s . • . 5 . • - s - A - $ - s . 8 . Qty O<V Total o::..n $ - f . s . $ . s - f'ago 3 Auaust e, 199& • CS) (JJ .._, ,_, CS) --"' CS) CS) " ,_, (JJ CS) m N (JJ w (JJ w U) CS) (JJ ,_, " gi ~ ~ H r -, ~ Ul -;], G) r, en .., INST"'··~~oN COST>i r I.ABOit. !OUil> . ow~.," ""'o I Ullit Filo Ollit Co'mllO•t. vegetable, delivered and 1ml' $ 37.88 C'{ D8camnactinn till/ha'l"ll~an, medium, to • 1.97 C'{ l>e~nfflflaCting till/bardhan, mediu~ to s I.S7 er Pe¥tilize, alow relea,e tablets, loam • l.21 Bach (tvdroaaadino I • O.Sl SY t,abor. ueneral (lan~•caoAn<rl s 25.00 "" Labor, .:1eneral tcOl'latruct ion) $ 37.00 H1I tabor, consultant, su1:1enieil'ln • 55.00 HR. Labor: Consultant, on•sice ra-deaitm. ~ 95.0D llR fLAIITS, Petted. 4" diameter. rnadium • 0,68 sacb Pl.Mn'St ~nteinar, l qallon, ·ntediutn s s 10. 02 Ba.ch PLIWTS1 Container, 2 gallon, mediums $ 16.47 each h 17 ian Pl.ANTS, Contatna:r, S aallon, med.iU?n • 29.lB Koch .. -,,, ~~ PLANTS, seed.1.na. by hand s 0.44 SY PLJIIITS: Slios (tirl.llow. red~csier) s l.l.2 S4cb ft.ANTS, stak.ea !"1llow) $ 0.9d Bach li.ental of deooffll'lactina tne.cb1ne..-v &, o"' s 70,65 !lcur Sand, co4~aa buJ.lder•B, delivered and s 42. 06 CT 8tak.ina ~at&rlal (sat 'O&r tree} • 7, oc Bach SUrvevinR, line & nrade s 605.H DAY survevtn~. lot locacloD ~ lines .$ 1,lSJ.60, ACR! 8\.lrvevina, ton-raab1c.tl .S 2 UO.og A= T(lllllld tnoaoil, i:,bJc: l:lan'OW, 20MI tr.t.etOt't s 1. 02 SY OTHn COSTS -1'111lOV!JHOU'J.' MONITORINQ ~BR!OD J'YJ>e O'nit Pr.le O'nit Inao&c1tion, annual S. 460. 00 BACH JftttnectiCl'J. final s S75, 00 BACH HaJntenance, setni-annual Maintenance, :am'I.Ual I MonitOl'inn. annual I W'aterini:a, 1~ or water, 60' agaker hos • 3.U 1-!SF IrriJ:retion -tem.n.Ornrv ! 1,000.00 Ac:re lrriqation. bUl:ie~ S 4,500.00 Acre I web-110m!Q1r.1n~ty\Vorlca/,oelflnal,•f1 S.nsltlve Area• Bond quantity Worltsheet jorITI 'total $ . ll . s - s . $ . • - s . • - a - s ,w~ .z.o ,&ilJ.01 .. rr $ - s - $ . $ . s - ! - $ . • . s - 'l'ot&l ~ iUt!O-ct) • ,;-7fi'.OO s . $ - s . • . Page 5 AuQtut 8, 1!198 • <S) U1 ...._ .... <S) ...._ 10 <S) <S) "' .... U) <S) co 10 rn w U) w U) <S) U1 .... "' ~ ~ H r -l ~ f'1 U) ,, ~ a, w HABITAT STRUCTUJl:!S (J.aolud•a ~eliverv\ ITBMS Uni: t'ost Unit faaoine.a iw1110~1 I iSc1cb Loga, (c:eda~), 'ti/ root wad•, 1~•-;.i:4• dia11.1 S 1,000.00 sach tog• {cad.Ir) li/o root 1t!lds, 1,•-24 11 di4111., $ U0.00 Bach r.oa •• tl/0 root wa.c:L!!, un-:24,~ 4iaiD., 10' lon $ 2415, 00 lfach Y.n.ot.9 w/ root Vada~ lf' .. 2.f" dhru., 40' long t' 46<1,lJ(I 3acb Rocke. . one ~man • 60,00 Ba.ch Rocks, two-man ' B5,00 B&eh Root wads • t63.00 liach RnawninQ' aravel, l:Vre l s ,2.00 (!'{ Ne.ir -l ..... $ 1,,00.00 saoh Weir -ad1Uatable ~ 4 000.00 Bac:b' :,, · woodv c!,,bris, laW18 $ 163. 00 Bach 3 Bnaae • a&nchorad S 400. 00 Bach. · SfiAd8 -on site o( s SO.DO Baell ~ sn.aa.s -i-rt!ld • 900.00 Bach DOSION CONTJIOL ITBl!S thl!t Cost Onit Backfill ana COIJ\Daction-embtmkllient G 4.B9 CY Crushed sut-facina, J 1/41' rrd.nua $ 7C.30 t"Y Ditc:h!na s 7.0l C'I 8xcant1on bulk $ 1.30 .CT .. , Fence, silt ·s 1.20 LP .:1 Oc..1 J\lte Mesh $ !. 26 SY MUlch, hv hand. straw, :il 1' deeo g l,27 SY Mulch, bv hand. wood chigs, ~· deep $ ~.25 SY Mulch, bv aiaohJne, straw, l" daen · s 0,3, SY Pl...,inn, t_..,orarv, CPP, 6" s 9.lO LP Plnl....,,.,, te-oruv, CPP, e• s 14. 00 LP Pininu, tefflnoray-U, CPP, 1•~ . s 18. 00 LP Plaat.ic covarina, Eil'lllll thick, d&JldnaCIC $ 2.00 SY a1o aao, tnac:hlne olaoed, alooes s H.98 t"Y Rock CQJJ&tr. Jfn.t~ance l00 1 ~1SJ:rtl $ l,545,68 ltach Rock Conat~. lntrance S0 1~1S'XL 1 $ 1,l71.l4 !!ach Sediment 1u:md :riser aeBemblv 9 1,695.U Saoh Sediment tZ"a"' 51 hiah berm s 15.51 LP' Sadilrei:i.t t.rap, 5 1 high bUlll w/ap!11wy ind. $ 59.EO "" Sodding, 111 deeo, level ground $ 5,24 SY ecddi.nq, 111 dasim., sl oned qround s Ei. 48 SY straw-bales, n1.ac:e and ramove $ <32 .00 'roll ToDsoil, delivez•d and sgrsad s lS. 73 CT I web-Bon0Qu1m1tyWoriahee1Fin1l.ldJ SensJttv., ANlllfl Band Quantity Worksheet Total $ . $ . s . s . $ . $ . s . $ . s . S Ul('i -CO J§'(l.0(7 'l'otal $ . $ . $ . $ . $ 6,~o-ro s . $ . $ . 4 . s . $ . ~ . s . s . s . $ . s . s . $ . $ . s - $ . $ . ?1ga6 August 8, 1998 • co u, ' .... co ' "' co co " .... u, co co "' u, w u, w "' co u, .... " CJ) ~ ~ H r -I I ~ Gl ~ en " G8N!lltAL ITDIB I Unit Cost Ul>it 'I'otal @encing1 cbain link, 6• biah s 18. 89 LP • . .renclnn cbatn link, corner ~osta S Ul.17 BacB • . tencinq, chain link, aata $ 211. il aach $ . Pencin.M snlit rail, l' hloh (2-rail) t 10.,4 LP -. . lencina, tem~ora:rv INGPB) s 1, :io LF s . Sirms, sensitive area bou:nda_, • 2.50 !a<:h • - STBBP SLOPS rsLOPB INSTABILIT'll . WRIT.B-IN I'l'BMS .... O'l"llllll NOTlr All plant pri<:ea tte t:rotn Storm Lake Orowers; Mabaab. Natives, Fourth Comer, and SoWld NatlV& "lants reontil1nttlfl, and tram rroatv Hol.low-a~d Abundant t,ife (seeds). lOl Clll>ITIIIOi!IICY & M08ILIZATtON, 1'01'l\L' web•l!GndQu.ontlty\Yotl<,heetFJn,1.>11 Setis,ltlve Areas Bond Quantify worl<,sheet i lZ76'· 'i/J $ l,<OO"J.11'L ~I /37(,, Jl. Paga 7 August 8, 1998 • CSI lJ1 ' .... CSI ' "' CSI CSI " .... lJ1 CSI (D "' lJ1 w U1 w U) CSI U1 .... " ~ g C H ,::; a r'li en <l :,;, ill "' lJ1 _,_ =I: __,_ ........ 05/10/2004 15:08 2535390514 SOIJNDBUILT HOMES SE 1./4 S14--T23N-R5E PAGE 55 ~ _ R-4 -1--~- - ~ '11:aOOlblial ...... TtlDl IUl!Ellt,lOla UAld~.IQ:lla __ .. ....... ......... 1NIII ....... ---_,_ Jltff'Gll.R _ ...... ..,_ "111114-tDWIE .., ....... .. . -I JDIIQ aJlllin' M -.. """""""' IDltal:fRQUII,:. --...... .....,, ... ...,.,. --"""" --'"'"" ---Cll'l'lll'Jll!llft:II ' 11:1110a»ffr....,fflllD8rR!tTa , -. OlltJ.IJIITJllll!!tlffllltl'III' .... -------- __ .... ---· _ ..... ... ..... scu r • ,on· es, 11, , . '"' 0 100 I R-4-j .... llll9IU,l:I alaf -------~-:::- 4 u, , . <a!), WE.Tl.ANO Fill. • 200 SO. FT. '&. ~ BUFFER Dl";TUA"B,,.NCE · A. El't' R.O.W. • 4,849 SO. .FT • n.. h' .t..O'!SI ... 0.340 so. rr . J, ~ 91.JF'Fffl 11:tf'V.cEMOO/.\~ AAtA • 1$.495 SQ, FT. ._ c:::> 8Um:A EN>W<CEMtNT Al<!:< • •S,ooo SQ. FT. (IF REll'O) {TO DE: 5U.EClm 6T BIOl.OG.31) . UT, 'O' A. 9Ul!ffrl ARl:A --$11,• SQ. FT. B, W£n.AN0 ARD-• 1~,'TCl2 SO. FT. PERMET!R ROW AAE4 • 24.llgJ SQ, n". ltMRIOFl PUBuC R1'Wl AR£A. .• M,.~i SO. n. INTDl:IOR PAIVA'R: RO'J> ARE11 • 17.SZS so. FT. ST'ORMWAJEJI Dl::TMCM lP.ACT '1(' ~ • 4,'21 SQ, FT • Sl'ORWW-.TER Dtl'Dl1'tON 1MCT V AR!1i • 35,835 SQ. FT. ~lJON 'TRACT ,. .. ~ • 14.871 SQ. "· ARt4 OF TRACT "U"' OUTSCE Of 100 'l'tAR WA'Tffl SLIRf"JoCE L£VEl • 11 Jloa so. n 3,ul !l li i ~ ., .. I • ! Pl 'Ii I .r t1. ! l-i ;1i' . 'Ji 1, " ;f © -;,- ·!" ,'i' :~ I ' " I " .. ' t-1 ' ~ ... ·" .if J t,--~---1 ..,,., ,r.. j i ~ 3 1 ~ .. / cr 0 i jj'. ~ i ~ I .,. '3 1. 0 I ' \p tr ' ' ,,. -- ' ., .•,.,. [t .<& f ,o-,r.. I ,~\ pit~ ~ f ,if I t I j -d ~ 0~ " ... }8 ~~('4, .,.._ J~ ~~ .. ~ > ~i @~ ,. ~ ~ - ;., .-~ :i ~ C "' r ,1· 'o 1 ·o '" ~$~ { & '? ;~© '\© -© ~~ I ' -a.:...t: "': ' ,. ,, ' ~ ' ,& w 'o ~ ... 1 .-"' ' "'i !;,_ .••• : ,-. (· " ?. ~ !C ~ ~t r.~ \_ ' ' I~ '. ' '" " I=; \J ,', " If ~ .... n·· ... ~ • ..... .. !! . --.~, JI .. o,~ .0,2..1 t ) ;1' 'cl' ~J 1 ; i C J . ~3 .. ~ ., :,-08 ' ' ""' w @ '~· -~, ,,. 1~ ~· J ... I I I I' I .I Ji 11 I ti ii' -l.1 II 11 11 =i] -- ... ._ 0 - "' % ti 0~ J ~ !i " ;l ~ ,. ~ I • I ' : 07/14/2004 13:07 2535390514 July!/:2004 Bruce and Joyce Osgoodby 13456 156" Ave. SE Renton, WA. 98055 206-200-6612 Dear Bruce and Joyce Osgoodby: SOUNDBUILT HOMES Confirming our conversation today, you grant the developer permission to enter your property for the purpose of installing a rockery on your South property line and re-grading your driveway to match the elevation of the new proposed roadway in the existing King County 136'h Ave. ROW. SBI Developing, LLC further agrees to re-gravel your dri'leway after the re-grading is completed and install a new 4ft tall chain link fence along top of the newly Installed rockery. Your signature below Indicates your agreement to grant the developer of"Evendell" permission to perform the work described above. We will do our best to minimize the impact to you during the construction and will communicate a timeline for construction to you as soon as one is defined. Your cooperation in this matter is greatly appreciated. ully, Kurt Wilson Land Acquisition, Mgr. PAGE 02 10/04/2004 17:10 2535390514 September 27, 2004 Bruce and Joyce Osgoodby 13456 156th Ave. SE Renton, WA. 98055 ·, Dear Bruce and Joyce Osgoodby: SOUNDBUILT HOMES PAGE 02 Confirming our conversation today, you grant SBI Developing,LLC and its contractor to enter your property for the purpose of reconstructing a keystone wall located at the Southwest comer of your property. As discussed, we will step the wall back to your fence. Your signature below indicates your agreement to grant SBI Developing and its contractor permission to perform the work described above. Your cooperatfo11 in this matter is greatly appreciated. Respectfully, ~-·· Land Acquisition Mgr. .JJ~2o~t; Bruce Osgoodby 09/01/2004 15:04 2535390514 SOUNDBUILT HOMES PAGE 02 Recording Requested By And When Recorded Mail To:Mark Sollitto CONFOIU1EII COP'i ~J) ~:~~?1i~0!~33 King County · S,~1 ~i~1v~4 i>i3 Transfer of Development Rights Program Water and Land Resources Division · CONFOR"ED COPY 201 So. Jackson St .. Suite 600 MS: KSC-NR-0600 Seattle. WA 98104 Transfer of Development Rights Certificate Number: 78 20 URBAN Development Rights Date Issued: July 29, 2004 Certificate Issued To: Name: SBI Developing. LLC . Address: PO Box 73790 City & Zip: Puyallup. WA 98373 E2061'142 lt~A 1 ~!5~1v!4 ~:a TAX ~373.80 SAL.& $21 , eee . ee PAGEeet OF 081 This development right(s) is/are transferred from the following certified sending site, pursuant to K.C.C. 21A.37: Sending site file number: ~V01.1.Q Granter: King County, a polltlcaJ subdivision of the State of Washington Parcel Numbers: 332305-9002: 332305-9062:282305-9101 This certifies that SBI Developing,LLC owns twenty (20) urban development rights removed from the sending site identified above, which has been qualified as a transfer of development rights sending site pursuant to K.C.C. 21A.37. Receiving site tax lots: 142305-9009 &142305-9022 ODES FIie # L01 P0016A & L03RE03B The official record of these developmc.tit rights is maintained by King County. If there Is any discrepancy between the numbe,· of rights identified on this certificate and !he official record, the official record shall control. If a_ny of the development rights identified on this certificate are sold, conveyed or transferred, the person acquiring the rights shall within ten (10) business days deliver to the King County Transfer of Developrnent Rights Program this original certificate. A new certificate In the buyer's name shall then be issued. The development rights may be used only on a receiving slte(s) that has/have been given final approval for additional residential density achieved through the transfer of development rights in accordance with King County Zoning Code (K.C.C. 21A.37). Approved by Representative of the King County Transfer of Development Rights Program fnteragency Review Coni"mlttee Signature Cenificate NumbeT ~ Date Issued 71 29104 ·, Page 1 of4 - 09/01/2004 15:04 2535390514 SOUNDBUILT HOMES PAGE 03 ii STATE OF WASHINGTON) )SS. COUNTY OF KING ) I certify that I know or have satisfactory eviderice that fiVkf,~ >o< ~, f'-'-1~. i_s the person who appeared before_ me, an.d said,person acknowledged that he srgned this instrument on oath stated that he is authorized to execute the instrument and acknowled~ed it as the Program Manager, Transferable Development Rights Program of King County to be the free and voluntary act of such party for the uses and purposes mentioned in the instrument. To Redeem Development Rights: State of Washington Residing at 1.4../'S7.JAI My appointment expires r,h~(o6 In applying for receiving site approval, the applicant shall provide the Department of Development and Environmental Services with either a copy of this certificate issued in the name of the applicant or a copy of this certificate with a signed option to purchase these development rlght(s). For receiving sites within incorporated municipal jurisdictions, the applicant shall provide the above documentation to the munlcipal jurisdiction and shall follow that jurisdiction's development application review process. Before building permit issuance or before final plat or short plat recording, the applicant shall deliver the appropriate TOR certificates issued in the applicant's name to the TranSfer of Development Rights Program. The applicant shall receive an extingulshment document showing that the development rights have been applied to an approved receiving site. The TDR Program shall confirm for ODES or the municipal jurisdiction that the requirements of K.C.C. 21A.37 have beer. met. Ceni.fieate Number 78 Date Issued 7/ 29104 !', Pae;c 2 of4 - - 09/01/2004 15:04 2535390514 'SOUNDBUILT HOMES . l ·,, CONFORIIED COPY Recording Requested By And , When Recorded Mall To:Mark Solllt10 ® 20040811001634 KC IJATER L Lt=lN ET"ISC m.09 -.. ,, 0~ 084 88111 2 ee~ 14:13 KtNG COUNT~, UA. King County Transfer of Development Rights Program Water and Land Resources Division 201 So. Jackson St., Suite 600 CONFORIIEtl COPY MS: KSC-NR-0600 Seattle, WA 98104 PAGE 04 Transfer of Development Rights Certificate Number: 79 PAGE001 OF 001 8 URBAN Development Rights Date Issued: July 29. 2004 Certificate Issued To: Name: SB! Developing. LLC Address: PO Box 73790 City & Zip: Puyallup. WA 98373 This development rlght(s) is/are transferred·from the following certified sending site, pursuant to K.C.C. 21A.37: ; , : Sending site file number: A98V011 o Granter: King County a poHtlcal subdivision of the State of Washington Parcel Numbers: 332305-9002: 332305-9062:282305-9101 • This certifies that SBI Developing, LLC owns eight (8) urban development rights removed from the sending site identified above, which has been qualified as a transfer of development rights sending site pursuant to K.C.C. 21A.37. Receiving site tax lots: 142305-9058 DDES File# L03P0015 The official record of these development rights is maintained by King County. If there is any discrepancy between the number of rights Identified on this certificate and the official record, the official record shall control. If any of the development rights identified on this certificate are sold, conveyed or transferred, the person acquiring the rights' shall within ten (10) business days deliver to the King County Transfer of Development Rights Program this original certificate. A new certificate In the buyer's name shall then be issued. The development rights may be used only on a receiving site(s) that has/have been given final approval for additional residential density achieved through the transfer of development rights in accordance with King County Zoning Code (K.C.C. 21A.37). Approved by Representative of the King County Transfer of Development Rights Program lnteragency Review Committee Vl,c~' Signature ~ Certificate Numbe,. 12 Date Issued 7/ 29/04 Page 1 of4 09/01/200~ 15:04 2535390514 SOUNDBUILT HOMES PAGE 05 STATE OF WASHINGTON) )SS. COUNTY OF KING ) I certify that I know or have satisfaciqry evidence that Mark S~Ultto Is th~ person who appeared before me, and said person acknowledged that he signed this instrument, on oath staled that he is authorized to execute the instrument and acknowledged it as the Program Manager, Transferable Development Rights Program of King County to be the free and voluntary act of such party for the uses and purposes mentioned In the instrument. :q/~ Notary P~bli:: and fort State of Washington .z ' d R~sicling at .!4=A-S7 • ,J M,y appointment expires coMC;, Tb Redeem Development Rights: In applying for receiving site approval, .the applicant shall provide the Department of Development and Environmental Services with either a copy of this certificate issued in the name of the applicant or a copy of this certificate with a signed option to purchase these development rlght(s). For recelvlng·sltes within incorporated municipal jurisdictions, the applicant shall pmV,ide tho above documentation to the municipal jurisdiction and shall follow that Jurisdiction's development application review process. Before building permit issuance or before final plat or short plat recording, the applicant shall deliver the appropriate TOR certificates issued In the applicant's name to the · Transfer of Development Rights Program. The applicant shall receive an extinguishment document showing t,hat the development rights have been applied to an approved receiving site. The TOR Program shall confirm for DDES or the municipal jurisdiction that the requirements of K.C.C. 21A.37 have been met. Certificate Number 79 Date Issued 11 29/04 ·, Page 2 of4 G COUNTY, WASHINGTON APPROVAL ~g~j~;~~N~INE Nd .. L03LOO 13 DEPAR™DIT Of OEVEl.OF'li!ENT ANO f/MRONMENTAL SERVIC, re~~'" "\Jl!l~--'"'* ~~G UNIT, LAND USE SERVICES OMSION KING COUNlY DEPARTMENT OF -"5SESSli!£NTS i APPROVAL NOTES: THIS REQUEST QUALIFIES FOR EXEl,WTION UNDER KCC 19A.28. IT DOES NOT GUAAANTE:E THAT THE LOTS WILL BE SUITAEL£ fOR DEVELOPMENT NOW OR IN THE FUTURE. THE LEGAL TRANSFER Of THE PROPERTY MUST BE DOt,JE l3Y SEPARATE INSTRUMENT UNLESS AU LOTS HEREIN ARE UNDER THE SAME OWNERSHIP. RECORDING NO VOL_.i'AG[ j4Jl.-'-'IU"li-f,vJCIWJU,<, I 1_7f! I .to? • PORTION or EX.WlNEO &. APPROVED THIS~ OAzof ~ •• 2o:21' 5;,qtt Mahk ffe .. 4ti,, ~rw • KING COUNTY ASSESSOR ~@!r_l<~Jm:.JSSESSOR !Y.[1;4 of _§.ff...,;., s.H. T._g~N .. R . .!:1£..w.M DECLARATION KNOW ALL: ,M~ IN TKi.sE PRESEITTS Tt,L.t,T 'II[ ;KE UNDERSIGNED" O\YNER{S) OF THE t.ANO 1:1-..G~IBEO 00 HERE8'f W;(E ~ 80lm°"81' lr<E ,l,DJUSTl,jEJ,if THER(OF PURSllO.'IT TO RCW 5e 17 040P+CVRE ;flS AWUSl}EtlT TO & THC GAAl'111C REPRESENTATION OF mt l>o'J,IE. N,O l>l;t.T SOJO .&dJuSl\o\fNT IS ~-~ ffiE'. f'liEE cotl5ENT ""10 ~-~ORDANCE ~,lHE D£SIRE:S OF THE OWNE!l(S) IN WITN£SS WHEREOF WE'. HAVE: SET OUR HN«lS »ID I t,t, lfl~. •' .... -.,• ... _, \ 0 ' " · · ~ m· ··· ,~ orru M1.I -. ~@ ~_;,, -~· Y~&__-, ------~ ,,.s,,,,P,,;i, Yd'.'* ~:.li ~ .-.,.~·~:'~r'!.<\, /~iON·~\ f t8~~~\ \ \ \ """' l _J l~~-r.;i~-·~.I STAlit'"6t'-~ASHI~T(IN': _./ ] ., f (~~~ \~~)'11,. $TATE OF WASHINGTON. •·.-.,~~.:~.o~,,,• /f!t'"~~-_}.;:=' / ~ f0 ti~y COl.ViTY CW f"{eY(:,e..~ J Y,,-' .,· I " / ~w,~, .,, J " On th1~·day per1om1.~!Y appuir~_!;l-"betor• H .-::• \ 111,\ ~ On thle day p1r11onally appearecl b1fo,,e me ROBERT ,.._ I.WR MIO _CL'TtJ[RA[ ~ •• ·•· \~-[~~.... 0.,,'w1) ,._ HY8LOM Al'fO OEBAA L ALBSO ..... ~..,....,. to 11• kno><n to_l>ol·tt,.• lndl.,tiduab d11c~1b1d in af'l?·wno ,~ t.o ae. kno-to b1_th1 1ndiY!dua1a ducrll,ed ,n and ...,0 executed the "' thln a...i. (c,'-ego,ng in'ltnnNlnt an11· .:· .. • °""'.._-eucuted tne wltrnn and ror,golng Jnltru .... nt and acknowledged that u,ey 5lilned tile•!!• H thel.<:'"frn .,· .,:· , ,,. eckno·dedg•c! that they signed the.a...., as tnelr /ree e:,d volunhry act ene: dud, tor i.r;hs .• GOd_,~\Jri;,:,.~u._,,· .Y :;/ and volunt•ry act and aeed, lar • use~-~Od purpa~n l'lereln m•ntlons~. , L,.,.'~·'c." 11,diJL-) ., r:/ ··. herein HnHanso. . (\t, . t, , ~~t";,~~~~c La,vn· . . 1./'l-JJ.t}..'r ,n O YUJ,1 ,17 .... • l·O'r ~pi~ntrr,enl 10.og · li c; <-.~::.::'/ .... I /0 ·Ok6f( -O<lte, oLo LEGAL .-rfEscR1P-TibNs LOT A (P.aRE... f!4Z30:5 0022J-".:· toJ.433 5q Ft \·. THAT POOT1CN Of nE 1-0RlH J'lll_.F Of Tl£-~ HALF CF TI-I;:. ~1™EST 111ARTEA CF THE ,um•IIES1 ll.J,O,Ri1:JI CF THE 50011-f.AST l).JAATI:llci:F SECTI!N t~-'TlJNtl9iIP 23 ~ RAN3E 5 E.-lST W.l,t, LYIN'.i EJ.STm.Y CF n£ EI.SleR.Y AARGIN CF 156th AVEN..E.st •s OCEIEl.'ltl KOO tp.my 6Y U;c--o IECCR:EQ U'aA KW. C(lJHY IECCRlil'G NJ. 1094243; TOGETI-EA WITI-J A tol-EXO.lBlYE EASEW0/1" Fo, Itq:ESS. €61£51; 00 UTILITIES OV8l I.KER AIO 4CRlS5 Tl£ ~TH l!i FEET CF U£ \E'ST.·±$7 FEET V.S.1£.lSl.RD FFO\ nE EASTffi..Y ~lN Q= CCUiTY OOlO F\IaiT-<F·W~Yl ll' LOT 2 Of SIO'lT PLAT l-0. 878~ l'ECCREl .lJIEl KOO q:µ,lTY flW:lll_.lµi t,{)_ 80022'3l639. IEa.Hl5 CF KOO crum. NJSlin;T(}t Al..9J T!XlETI-£R l!ri'H A ~I\IE ~: Fm ~· EGESS »o UTn.rrIES OVER \HSI ~ .lf.:RliS TI-E SOJl'H 15 FEET ._(F U£ E,.ST 22 FEET tF Tt£ IIIEST l99 F.Elc,, AS ~'ffOt TIE EAS?m..Y IIAA,lN IF SAlO 156th Aveu' SE. ci,::11"11.l PCFITIOt!'U' THE IOll:,,r t-11,l.F CF n1;:·rumtJ-el..F Of TI-E ~Si WNITEJ:I CF Tt£ romtEST ~y Of~l£p. ~Jl~\~·~~r::nttl I~}~--~ IDlTH lWa 5 051:_.~.II. LYIMi E.lSTE!l..Y IF TI-E r~;,;~~;~07:::,.f~:;,L,~f,~;·;;:;;·~··· .. E1CCl:J'T m.o.T PG!Tla-1 Of um EAST HALF CJ' TIE IG'ITHEST (JJ,/.ffl°El'l"tF Tt£ ~.l$'.f' IJ.IARTEA O:,s.utl:~ ~~ ~F~ CC1ffR CF $.UC EAST ~.(F TI-£ tamt£ST,~,:~ THE ~"T ~ / ~~ ~~~ ~CF~~25~~Jiff:i-~~=~l~~-~:,,,/ JEST LIIE CF" 51.ID EAST HALF CF n£ tam1£ST a.wlTUI CF TtE 6WTl£AST IJ.WA"EA; ~ SOJTK 0077U5" ~~£tt~\~Tt£E~1~.t:f~SA:o:~~ L~ ~~~~~ ~ 1';f~r-~ ::" ~ ~ ~y ~ml~ ~V:I~¥ ~~~;~C[KE) 1,wi ~w; -~,:£CXfOOO ~;,a;ii~\::.;: SITUATE IN fl,£ CD..HTY CF Kit«i. STATE CF IUS'llNGTcl'I. .,.,,., •.• ,• . '°.-. s.l;J·~~EY9.-~).··:-,c:'c)RR't<:r~~~, LEG..;~·,/~q~-l:1PrroN -. ~tj$f~#~~~?~~~l£-~~.:~~R .. ~·-;.,CTI04 14. ro.t&fII' 23 Wln{ FWa ~ . .. .. .. ~ n1ufkRmt1 IF. TI-£ SttrJ#"~ a.wrrei{ CF ~··"-iam~s1::~TER CF Tl£ SDJ1l£AsT WA!lTER Of' SA.IO SECTION 14 Clp,G &JJTll "CF"•i1¥ Fi:.u.owoo i;e'.DUeED:lltE: .,·: OMel:IMi A~·:tt-e·llffll;(IS>-·~ CF~-~ ~r ~ CF THE /Glnt£ST·QJAATEl1 CF TIE ~1 OOoRnJ1; Ttea. 500Tii 00~1· IEST ..q__(tG n£ EAST LIit? CF SI.IO &ul}£.lSJ C1.J1R1ER !35.66 Fm TO TIE !EiWm.G CF SAIC LDE; 1t£M:E ,amfoow.'51· IEST, eAAAU..a WllH Tl-£ ra:ntt LDE IF SAID SWl"1£lST 111ARTUI tF n£ N:RTaEST ~,tF Tt£ !µJTIEAST GUlF!TU\ ~.61 FEET TO Tl£ 1£51 LOC lf SAW EAST ::; :CEP7 =:a=!:::==.:=== ::w:: ::Ll:~lrl> ~. 2500004: SITUATE IN 11-E co..trn' CF K!Nl STATE CF II~. SURVEYOR'S NOTE Tl£ /el l.EGlL !EDIIPTilJ,I FCII UT/ 9 lil.s BEEN lflITTfiH l£IEtN WITH n£ INTENT tF S..lMlN.I.TIK: Tt£ POSSIEl.E HIATIJS BETiEEN 1rE SW1H L»E CF TI£ l'IU'EFITY 1-BEDi OfSCPJBEO NO ,l£ NJlJH LJIE CF TI--E ~ 14lIOt .l,().JJJNS TO 11-£ swrn. 11-£ POSSIBn.m CF A HIATW IS CAlaO BY A OIFFER;HT S1olAT?I-G P()Jt,T FCII Ir£ F.!11'.&Tm; 10 UT/ 9 THAN Tt£ 4C1Uo>L DEED teiCUFTlDi FOi TmT EXCVTICN. THIS JEW a::s:::JIIPrnJ,1 CIESCRI2£S Tt£ /OiTii Lit£ CF TI-£ EXtEPTD>I IN TI-£ 5.uE IWtER AS n£ CEED FCJ:I Tiil.T EXCEPTICN, Tl£Rc8Y Rl'.ITECTTo6 Tl-€ 1NTEGIITY N'IJ UM"IHJm CF 11-£ LEGAL IESCAIPT1CN5. ·· .. EASEMENT, COVENANTS, AND RESTRICTIONS, ,(iAOM ;;~·~!'1.&.HOt!.}ITLE INSURANCE COMPANY SUBO!VISION GUARANTEE No. 870890 ITEM -;: •' E..I.SEIENT: ._.'..GRANTEE; !<ING COIMTY WATER DISTRICT No. 90 .• ····•~· :~ .. :WATER AND SEWER MAINS _ .. ,· ·.. ·RE~~~t~Y ~~~~: ~~c~~I.% ,!~~~1~10551 .:"'iTEM a .. '-EASBIENT!--'iRANTEE: KING COLNTY WATER OISTRICT No. 90 ' ~POSE: lt.c:J"ER ANO_.SEWEB..>J•INS AFJ'i.A .I.FFE(;l°f:D; NCIATHERLV J"d-'·f~T OF P~RCEL A •. .. ef:COROEO:.~· ,XJJ,.¥'·11. 1975. i:ie:coRO.lf"G No. 7507170570 ~ "'"£MO&,;, II)' "''"'"-"'o. ITEM'.9. EASEMENT: ·."GRANTEE~·:Pu13ET SOUNO POWER & LIGH"J. 1r.oo-,.o._:t-,oe><:>1wo RECORDER'S CERTIFICATE .................... 11:f', FILED FOR RECORD. nHS a:!/ .... OAY DF f\!kr, 20 Q!,\. AT P,M, IN BOOK __ (JK.oFf.-.~ PAGEJ01.AT ntt1REOU£ST OF G. PHIL SARGENT ''Wi!AGtlC····· ,'1 . LL ,I! 1/-,d.4:-,;~i;·'· l.ANO SURVEYOR'S CERTIF!CATE THts 80llNDARY LINE ADJUSTMENT CORRECTLY REPRESENTS A SU~ MADE BY ME OR UNDER MY DIRECTION IN COHFOIU,•,ANCE W1rH STATE AND COUNTY STATUTES. ii QVC?.J G. f'HlL S>RGM J'J•1•s 1-tS-01{ ""' . . .·. PURPOSF!. ,afCTRIC Tf\A1$1USSION OR: OlSTRI~IlON AREA.:.l.i=fRt"TED: A!:; C!iilsJf!l,lt:TEO 0¥$1 PA.r:it!fl er·-,,.- ·· •. ;: •• REC_(]RDE!I{ FEBR~:?3_. ·1s~. REcttAoms Mo. 9.562~30.C'lf.i.. ITEM 10. RIG1:f1:TO IW<.E"NECE"SSAAY GUTS OR"¥-I.LJS UPOl:,1.Vn-fE.·.u.ND .~·.,,· ·•.... J1iREIN;!IESCAI!lal. AS ESTABtI~ W:·VOUJkE 31 OF ., .. •.=!~~~~~ ·~rn~r-it~?_E ·,ns_/. .;:'· .. , ..... ,, !" . .:.''':, ... ,,,· ~D S "· '., .... -····1···' . Marr/.Nyblom. Bound,y~Lin.:.-AdJus~me~.~ ryco urveyrng, nc. . , . ,.--, . , 1 2714 VALLEY AVENUE EAST OWN BY • 0.TE l;'ftlNTEO Joa NO SUMNER, WA 98390 LS 3,/~&/2:004 . 20030\'2 253-826-0300 fox 253-826..:.9703 CHl<O. 8Y P.S. SCALE ,·-100· ·.:!i.HEET j\, 2 ~ IG CO.LINTY, WASHINGTON sou£ibARY LINE ADJUSTMENT ::i • , ~ AREA '°' CLO -· R-ECOROlNG NO VOLt;·AGE ua:-e F••t lo 11 NEW 1-,wo· .... SCALE: Q;'2'Q NO .,,l,.D3L0013 .. A B """" ""'"' '9 ,00 0 LOO 200 •NOTE: PORTION OF Cent_e•_. '~tion_ ,i:~rner .r,:::·· I-_ ~ __ _ Sect,ll,n 14, .fncosed :.= I :S :;l ~ lHE:HGIRTH UN[ o, NI:Ml.Ol" a IS al 51.J--_ l'al!l0:11, WENOl<TH U11E Of'NNUlTA IS ~IIIIIIIJ.f;l.Wlffi iONOJOFWSIJl.l111 Of' THEEXISllf<• -o.otNTI.JMt.~ 1:in-lA'IEKll:U:• 1111:l'M-U. !fW 1/<1 of _§fl_ 1/4. s.J.:1-_, T.~J_N., R.Q.c: .. w.~. r.,rfon P!P;,:1" with 8~-9"9,S I ---... \. I I J ttrr· DERRl'HURS'..r t.·-Pin \t1SITE?" ~uly, :z904 .. / ,· .. I ··,·-:. I .. ,. I • cen;oo 0';oo VOL.166 PAGE 7,1 J" Bross Cop ln HELD peJ nm,rencild .·.· I e·-~ l ~ ~ j A~-:,. I 6D -,. c.,p & P\it? I I Concrete Cose pe survey;~~) ;_;-· · .-.=1 · I 1~!0ll ,. --.,. 3ll6C50 ~19 ,,,-,.·,,:-· J:iii<:D Of!Jd' ~ .. -. ~ 01~1 f...,.. 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I .-. · ELEVATIUN 468.87 / ;.,{,·:-' a'i.;',~,-·of sU1'.0~( · ·"""'" ----i •· LOlPo'oi'ii .,/· ~ ,_ -:-{ __ ,· ;!u~:'Es~: ~!E~om $JHION , ·'t°Jl,.,f-···nns SURVEY 15 ca~SEO DNA PAEVrous SliA'/l"Y OF : ""'"'"'"''"'E•s,...,o,H""'',oar ~IT-t<P-atesx DATA COLLECTOR co 1111s l'Rtf'ERTY. P.EcoRD OF ,SUIWl::v AfN 9s_oe099000 0 .... 1r : a """''"' ... 11£ :Dmbs, -~"' sm!tll.. I!-· 1 I il.) KI14G ,~a(M\. ~~lti:ii:-:w,• t<l.llS !E15! : "< I PROC(OUR£ USED ·:,. .q I ij; .,' _·.· ·' .. .. ' :S FlELO TJIAVEnSE Ii. EU:"CTRO!HC DATA COLLEt:TlONI ··-·.,~"J·-"'·llASIS Of B[ARINC .( /.' _. ..-· ·t-li!J:\I;~~-:-,;::i I I 11EETS OR EXCEEO:; J3.:-lClD-O',O I 8 MONUME.~TS::THE W!:Sf,UNE CJ",,TIE SOUTH!l-1.Sl_[JUJJITER ·::. : ;;cr~'?'9 CO v-, "'•lffi AFN950GO!i9008, ROT~'l'rn·:.0·1s·4g·_,; •: _,-:.. :·.:]II" .... ,..,... _ 1 ..!!2!l... C ,?; OF SECTlOl'I l4. AS -s-t[JIIN _or.I AECORO Cf.• SUlYEY, ·: ' ~-'""I J i'51SO 009Q °i ~ ·::,,_ ,,.•·' -7-:f--·',";".,--:.:> ,,,-~/-.::::;----~Of~~~~~~<F-~~°""':!:"--.._ ! tf lotONUlotENTfOUNOTH/SSURVEY Cl,) "'1 :;:!; ~SU!!-~ .,•' . '•· ... ,.,.:,• . :.' ><-x?S-~-><-~-J.-x-><-><-><-x _ 1 r--0 FtU<ll PFIIPERTY COONER AS JJ,(lJCAT£0 :, 'I~ PL.H Of CAROL~ood' . .''M'l4-·7t0h2110!!8~ •• .·. I . ,y .. . :: ::-,... . I • SET REl!AR i; CAP LSI 6228/3<1145 I q., 1v PLAT OF ROSE G~R~S. AFN 6?61014:: ''· J Lul 7 / ,:· -:·· 4• Bo.<5~d w·,;:.; 1 1 <J FIRE HYDRANT §::1 ~] ~ ~~~.,gFO~l~~~e~/~~N;B~~:~~:u.lJ'~-.5597966-·,f)p··-''s: . .t:,:l / ::·~ .-.-" feo_•.O .• lla'.'l·,. I ll. WATEl!VALVE: ~, -AECOFlO OF SURVEY, Afll 9~08099008 (R);._ 11, \.;-.·,., lot.a· -.:: 2e.t<"Jt ·'··.,. \!;J' WATER METER ~· "' 2,'. ··::-. .,•' W!!O(l."llCUI J '--1,' !f .-:·· I SL Ji. nECTRlCMEIER ' I el _ ~''..:_'_,,,_,,).;:.•V • . . ~-E -51¥f'Z/.'D"E"t;:,j-55,.... t-"o750~ 0 PHONE 011 CABl£ PEOESTAL 5 1 · \ · x-0< x-><--X I I m' CAS t,(ETfR \"I •-~ SE J38lh Place ---.,,, .. ..:· L 4;·11 ,.,,-;::, ~-::::-;. "=s~ _ 1·i -~-CHAIN u_NK 011 WIRE FENCE ~1 ""-' ~ j I .-. "9 .-:-~ ,•--......---,.. -,1, c.op t --IIOOCI F<eNCE \Q , _ _ _ _ ·;. ,... ;:Frnce .. Born . • 4'l-1og wi,-LB~ -__ ..::--.JI-IIATfRLlNE ? I ""-I ~ ] _ /, ·: •.•••. }··_..-, Encn,QClia .. r~.-..:e r-· I =BlJI.OING_S :.:1 'i<J G d Lot !I ;: 1 loot" .;: ..... ,,. (M) M£ASI.JR£0 ":! 1~ ar ens ' 1 •· 1~ _._. ,, .,:· 1 .J., ± § VOL tJ:J PAGE 69! lol 10 ' I .. . -PRf:JP~$ED p4.r 11 1::.aJ: 3 . I -, Nu:h:ols Place S' 8rcss Cap in t '------"-J J:iJ3POOJ-5 _ .. l,. Concrete Ccse per ; , -: • •· ROS 9508099008 . . t:.-._. .. . ··-.,.-Nat Visited ~-------------------------~~-_J_±_4_t!!-~t}"~'!.!.__ ----' -__ ·_ --:___ . -__:__.,,/~ ----~~··:,-· ·--i;l:i~~os,t4 c~;~;.sy South 1/4 Corner CONC MON W/COPPER PLUG Slla"56'56:E 2617.72 'Sil!l'111i'07:'( IRJ ::,-··~ ----,.--_.~ Section 14 VISITED March, 1999 •. . . ~ Survey & Map~lng-.. b( .. Dryco Surveying, Inc. 12714 VALLEY AV£NUE EAST SUMNER, WA 98390 253-826-0300 fax 253-826-9703 " .-:· .,-.-·· y ·=-,,, •. Mair/Nyblom.''lloundiy LirHt Ad justmenV ;: ,. ·. .-'"'=· ' OWN. 6Y -. I [»,fE f1llNT£ll I JQ6r NO_~-.. _.:- LS .. · .. ·.7/J-.°i/200•· (2003012,/ Ct.KO. FJY I sc,cc '[ s~_n.. .J,. P.S. 1·-100· ··::.2 or.:' 2 08/18/2004 12:29 2535390514 AFTER RECORDING MAIL TO: Name Address City/State SB! Developing LLC PO Box 73790 Puyallup, WA 98373 Document Tltle(s) (for transactions contained therein): -1. Temporary Construction Easement SOUNDBUILT HOMES Reference Number(s)-of Documents Assigned or released: Grantor( s): (Laot name flrsr, then fim name and mlddle Initial) 1. Mair, Robert 2. Mair, Clyderae [ J Additional information on page of document Grantee(s): (Last name Hrst. then first name and middle Initial) l. SBI Developing LLC, 2. [ J Additional Information on page of document Abbreviated Legal Description as follows: (I.e. lor/block/plat or sect!on/township/range/quartcr/quaitor) ptn of Nl/2 Nl/2 NW 1/4 NW 1/4 SE 1/4 Sec. 14 Twn 23 N R 5 E Assessor's Property Tax Parcel/ Account l\lumber(s): 142305902207 [ X J Complete legal description Is on page 4 and S of document PAGE 02 [ ] I am requesting an emergency nonstandard recording for an additional fee as provided in RCN 36.18.010. I understand the recording, processing requirements may cover up or otherwise obscure some part of the text of the original document. - 08/18/2004 12:29 2535390514 SOUNDBUILT HOMES PAGE 03 After recording return to: TEMPORARY CONSTRUCTION EASEMENT Reference#: N/ A Granter: ROBERT MAIR and CL YDERAE MAIR Grantee: SB! DEVELOPING, LLC . Ulgal Description: PTN ofNl/2 Nl/2 NW 1/4 NW 'A SEl/4 SEC.14 TWN 23 N RS£ Additici!!al Legal Description: Attachments l and 2 Assessor's Tax parcel ID#: 142305-9022-07 The Grantors, as named above, for and in consideration of mutual benefits, do hereby grant, bargain, sell, convey and warrant to the above named Grantee, its successors and assigns, a non-exclusive temporary construction easement for purposes of constructing, reconstructing. installing, enlarging, operating, maintaining, repairing and replacing an underground stonn drainage pipe and associated appurtenances over, under, through, across and upon the following described property in King County, Washington: . That certain perfectly square area of land, in the southeastern most corner of the property described in Exhibit A ("Parcel A"J, that has, as two of its sides, forty (40) feet along the south boundary line from the southea.qt comer of Parcel A and forty (40) feet along the east boundary line from the southeast comer of Partel A ("Temporary Easement Area"]. For the purpose of constructing, reconstructing, installing, repairing, replacing, enlarging, operating and maintaining .an underground storm drainage pipe and associated appurtenances, together with the right of ingress and egress thereto as required and approved by King County, for the purpose of providing drainage service to the property described in Exhibit B [~Property"). This easement is granted subject to the following terms and conditions: I. Grantee agrees to use reasonable care not to damage any structures or utilities on Parcel A and agrees to immediately repair the same at Grantee's cost and expense if Grantee, or Grantee's agents damage Parcel A structures or utilities. Grantee further agrees to use reasonable care not to damage the landscaping on Parcel A or the Temporary Easement Area and to return said landscaping to at least as good a condition as it was in on the date of this Amendment, prior to expiration of this Easement. 08/18/2004 12:29 2535390514 SOUNDBUILT HOMES PAGE 04 Construction Easement 2 2. Grantee further agrees to indemnify ancl defend Seller for any claims resulting from the acts or omissions of Grantee or Grantee's agents upon Parcel A. 3. This Temporary Construction Easement shall expire upon the date Grantee's construction of the storm system. and related appurtenances is complete and Granter has signed a non-exc.lusive permanent easement within the Temporary Easement Area as are required by King County with respect to the actually constructed stonn water system and appurtenances described above. Grantee agrees to use its best efforts to have such permanent easement area not exceed the south 18 feet of the east 25 feet of Parcel A, and to minimiz.e any above ground appurtenances on Parcel A. Notwithstanding the foregoing, Granter shall not be obligated to execute any permanent easement which so far exceeds the south 18 feet of the east 25 feet of Parcel A as to, (i) interfere with any structures or improvements located on Parcel A as of the date on which the easement is requested, or (ii) to materially diminish the fair market value of Parcel A. This easement shall run with the Property, and shall be binding upon the parties, their heirs, successors in ~~~ . ~ IN WITNESS WHEREOF, the Grantor has caused this instrument to be exeaited thiJJ.. day of July, 2004. c:~ a -zyezu,;_ ' Nl 111, D, Robert Mair 08/18/2004 12:29 2535390514 SOUNDBUILT HOMES PAGE 05 Construction Easement 3 COUNTYOF~e,yCQ.) ) ss STATE OF WASHTNGTON J On this day of J:JJ · day o , ~ before me, the undersigned, a Notary Publ.ic; in and for the State of Washin , duly commissioned and sworn, personally appeared ROBERT and CL YDERAE MAIR, to me known to be the individuals described in, and who eitecuted the within and foregoing instrument, and acknowledged that they signed the same as their free and voluntary act and deed for the uses and purposes therein mentioned. WITNESS my hand and official seal hereto affixed the day and year first above written. - - 08/18/2004 12:29 2535390514 Construction Easement SOUNDBUILT HOMES EXHIBIT A PARCEL A PAGE 06 4 THE WESTERLY 199 FEET OF THAT PORTION OF THE NORTH HALF OF THE NORTH HALF OF THE NORTHWEST QUARTER OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., L YJNG EASTERLY OF THE EASTERLY MARGIN OF I 56TH A VENUE S.E. AS DEEDED TO !GING COUNTY BY DEED TU:CORDED UNDER TU:CORDING NUMBER 1094243; TOGETHER WITH A NON-EXCLUSIVE EASEMENT FOR INGRESS, EGRESS AND lJfILITIES OVER, UNDER AND ACROSS THE NORTH l 5 FEET OF THE WEST 187 FEET (AS MEASURED FROM THE EASTERLY MARGIN OF SAID \56rn AVENUE S.E.) OF LOT 2 OF SHORT PLAT NO 878133, RECORDED UNDER KING COUNTY RECORDING NO. 8002250639, IN THE RECORDS OF KING COUNTY, WASHINGTON. SITUATE IN COUNTY OF KING, STATE OF WASHINGTON. 08/18/2004 12:29 2535390514 SOUNDBUILT HOMES PAGE 07 ) Construction Easement EXHIBITB PROPERTY 5 THE EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHWEST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH, RANGE 5 EAST, WILLAMETTE MERIDIAN, IN KING COUNTY, WASHINGTON; EXCEPT THAT PORTION OF SAID EAST HALF OF TIIB NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SAID SECTION 14 DESCRIBED AS FOLLOWS: . BEGJNNTNG AT THE SOUTHEAST CORNER OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER AS THE POINT OF TRUE BEGINNING; THENCE NORTH 25 DEGREES 21 MINUTES EAST 523.99 FEET ALONG THE EAST LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE NORTH 88 DEGREES 7 MINUTES 58 SECONDS WEST. 653.61 FEET TO THE WEST. LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE SOUTH 0 DEGREES 27 MINITTES S SECONDS WEST 525.82 FEET TO THE SOUTH LINE OF SAID EAST. HALF OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER; THENCE SOUTH 88 DEGREES 17 MINUTES 35 SECONDS EAST 653.84 FEET ALONG THE SOUTH LINE OF SAID EAST HALF OF THE NORTHWEST QUARTER OF Tll! SOUTHEAST QUARTER TO THE TRUE POINT OF BEGJNNING; AND EXCEPT COUNTY ROADS. THAT PORTION OF THE NORTH HALF OF THE NORTH HALF OF THE NORTHWEST QUARTER OF THE NORTHWEST QUARTER OF THE SOUTHEAST QUARTER OF SECTION 14, TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., LYING.EASTERLY OF THE EASTERLY MARGIN OF 156111 A VENUE S.E. AS DEEDED TO KUNG COUNTY BY DEED RECORDED UNDER RECORDING NUMBER 1094243; EXCEPT THE WESTERLY 199 FEET THEREOF, AS MEASURED FROM THE EASTERLY MARGIN OF SATD 156111 AVENUE S.E., LYING SOUfHERL Y OF THE NORTH 30 FEET THEREOF; TOGETHER WITH A NON-EXCLUSIVE EASEMENT FOR INGRESS, EGRESS AND UTILITIES OVER, UNDER AND ACROSS THE NORTH 15 FEE OF THE WEST 187 FEET (AS MEASURED FROM THE EASTERLY MARGIN OF SAID 1561 H A VENUE S.E.} OF LOT 2 OF SHORT PLAT NO 878133, RECORDED UNDER KING COUNTY RECORDING NO. 8002250639, RECORDS OF KING COUNTY, WASINGTON. ALSO TOGETHER WITH A NON-EXCLUSIVE EASEMENT FOR INGRESS, EGRESS AND ITTILITIES OVER, UNDER AND ACROSS THE SOUTH 15 FEE OF THE EAST 22 FEET OF THE WEST l 99 FEET, AS MEASURED FROM THE EASTERLY MARGIN OF SAID IS6 111 A VENUEN S.E., OF THAT PORTION OF THE NORTH HALF OF THE NORTH HALF OF THE NORTHWEST QUARTER OF THE NORTHWEST QUARTER OF THE SOITTHEAST QUARTER OF SECTION 14, 08/18/2004 12:29 2535390514 SOUNDBUILT HOMES PAGE 08 Construction Easement 6 TOWNSH1P 23 NORTH, RANGE 5 EAST, W.M., LYING EASTERLY OF THE EASTERLY MARGIN OF SAID 156TH A VENUE S.E. IN KING COUNTY, W ASHJNGTON. CORE DESIGN, INC. BELLEVUE WA 98007 Regarding Hearing Examiners Condition #19-a Core Project No: 04009 11/10/04 On Nov. 2, 2004, a field visit was performed to verify/review the drainage issue associated with the existing ditch in the vicinity of the easterly line of Lot 12, Rich Lea Crest (address 16046 S.E. 142nd Street). A drainage complaint was filed by the adjacent homeowner, Don Gregg, on Jan. 10, 1997 (complaint #97-206). A condition of approval of the Evendell Project includes stabilizing and re-grading approximately 50 to 100 feet of the existing channel to adequately resolve flooding that has occurred in this area. Based on field observations, this work appears to have been completed. See attached photos. The timing of the work performed is unknown, but probably occurred more than one year ago as the ditch excavation has naturally re- vegetated. The ditch is now approximately 5' wide and 5' deep in this location, which is substantially larger than upstream or downstream of Lot 12. 04009 HE Condition 19a, 11/10/04, page I :"t------~ ) ., ' +' ,, -?"IQF t,3.43 {. ' •,. 5 ; U ' j .. L6C"ft7t OIN f;:XL'77'IN (J· Dt7.1H ®. L-oo~,~{:. w&5-, e ~J;~7f;(Z.t,,vvx: () ~ ex15,,wf:> l:::>\TCH /tto..-.J6 -rr1E IYOf2.7rt /flo(,;~7y ltl'V'€ OF l-o-r l-Z../ fc.A-7 OF-"/-/CH ~FA (!flF"?i F/Z-On-IV..€. COa~~ll C:>1=-L.-01 11,. \/\i'~H lCr ftf'Pf>o:,(1V1t'i7t;t,-f ~ ' "t>E-Ef' ,, 5' w ,t;, e A7 -r,-.,t ~ o 77 oM A-r-> r> lf!l'-171 W, t7 G-A-7 ll-'1 ~ -?"c:::>P. T.;>,-rrH \N lb'Z.,...,( AvE Sf (Z..1C>"t7-OF-L.v~y ff{.,oM, 1\)_'f3;. l!e>(t~.At c,-F-WT LI , Pvt"r-r Of fZ..\CJ.1 l-~'4-Cfl~r, \ I ~ l O -1..0 ~· L ooic,~ 6 (\) 0 ~.,....., (!:! C 'f3 ,,•.rr F fZ t.1 w E Of-~)('.L5'7 J11Vf> 1:, \ ,(!)-t 1~ }b-Z..R f+vE 5£ f2.1 6'1'fT-Of=· Wl+y (Sit-;,, / OF-l-OT 10/11 0~ PLA-7 OF TZ-IC,t /....EA (!'p.£57, 1:::>1,('J.,( l'7 ft-ff ~oy_, M /t'7 &t-Y 5' °'t>Fr;p ft-vv'#i;> Io '--z.v · vJ •OE ffT -roP frwP 5' W 1t>E +/-lt7 "f.:!;o 77 DM, , - 11/03/2004 16:36 2535390514 11/03/2004 16: 56 4258275424 . SOUNDBUILT HOMES AES! Associated Earth Sciences. Inc:. Tecbnncal Memo:randUJ1m Date: November 3, 2004 To: From: Kurt Wilson SBI Developing, LLC 2S3·.S39-05l4 Melissa Magnuson. P.E. Bru~ Slyton, P.E. Subject: Off-Site Retaining Wall Project NIIJlle: Evendell Plat Project No: KE04323A PAGE 02 . PAGE lill/02 Associated Earth Sciences, Inc. (AESl) bas prepared this memorandum to prO'o'Jde geotechnical recommendations for construction oft.he proposed cast-in-place retaining wall located on the o.orth side of SE 136"' Street. The wall will be constructed as part ofrigh1-of-way improvements and will StJpport the neighboring property· to the north of the east-west trending wall. Based on plans prepared by Core Design, the retained heights will range from 2 feet at the ea..<rt end of the wall to 10 fe<et near the west end of the wall. AESI completed a report for the Evendell Plat titled "Subsurface Exploration and PreJimiriary Geotechnical Enginee,:ing Report-Evendell Plat" dated November 16, 2001. The wils encountered during the field study for this repo;t consfati:d ofV ashon lodgement till. It is anticipated, but should be confinned by AESI during oonstructi.on, that the subject cast-in-place retaining wall location will also comprised of this same aoil. TiJJ typically has high strength and low compressibility characteristics. As such, the temporary cut slopes necessa:y for1he cast-in-place wall can be planned for 4 vertical feet transi.tioning to a 'hH: IV (Hi:rrizontal:Vertical) slope. Horizont11,1ly backfilled walls that are free to yield laterally at least 0.1 percent of their height may be designed using an equivalent fluid equal to 3 5 pounds per cubic: foot (pcf). Fully restrain.ad, horizontally backfilled rigid walls that cannot yield should be designed for an equivalent fluid of 55 pcf. Surcharges due to traffic, foundations, or sloping ground muet be added t'O the above values. The lateral pressures presented above are based on tbe conditions ofa uniform backfill consisting of on-site soils .compacted to 90 percent of ASTM:D 1557. A higher degree of compaction ls not recommended, !IS this will increase the pressure acting on the wall. A. J.ower compaction may result in settlement behind the wall. Thus, the compaction level is critical and must be tested by our firm during placement. · 1 - 11/03/2004 15:35 2535390514 :1/03/2004 16:56 4258275424 SOUNDBUILT HOMES AES! PAGE 03 PAGE 02/02 Footing drains should be provided for all retaining walls. It is imperative that proper drainage be provided so that hydrostatic pressw:es do not develop against the wall. A minimum 1-foot-wide washed gravel blanket drain should be placed behind the wall. This wall drainage ~ould connect with the per.imeh:r footing drai.n and e,i:tend to within l foot of the ground surface. Lateral loads can be resi.sted by friction between the foundation and the natural glacial soils or ·supporting structural fill soils, or by passive earth pressure acting on the bmied ponions of the foundations and keyways. The foundations must be backfilled with structural fill compacted to at least 9S percent of the maximum dry density to achieve the passive resistance provided below. We recommend the following design parameters: o Passive equivalent fluid = 300 pcf o Coefficient of friction = 0.30 The above values are allowable and include a safety facto, of at least 1.5. If you should have any questions, or require further assistance, please do not hesitate to call. 2 11/09/2004 17:19 2535390514 SOUNDBUILT HOMES PAGE 02 Issaquah School District Ne. 411 565 NW Holly Street • Issa ueh, WA 98027.-2899 • Phone 425 837. 7000 Janet N. Barry, Ed. D. November 7, 2004 Kurt WIison, Land Acquisition Manager SBI Developing, LLC Box73790 Puyallup, WA 98373 RE: Pedestrian Access to Liberty High School Dear Kurt: The proposed pedestrian connection Via Tract "A' in the existing Liberty Lane subdivision has been reviewed and approved. · This should provide the necessary authorization reques1ed by King County and aUow your design work to proceed. Let me know If you need anything else to continue the process. If you need access to the school site to take measurements, gather information etc. contact the school office where you will need to signs in and sign-out. Please forward design drawings to me as they are developed for review.and approval. SI S Crawford D1 ctor of Capital Projects Board of Dlraclol'9 Constance L. Fletcher• Lany W. Ishmael • Mark Wamer • Mlctiael Winkler• Jan Woldaalh Superintendent ) .. 7. OTHER PERMITS: Permits from City of Renton and Water District 90 are required for the water and sewer design. 1 : I I I ' i I J ' I ! --·~ __ :_i_ __ ;r --~ _1 -~--.. ~ -~ -~ _ ~ -l . ;_ _ ! _ ·r-L _ ; . , ' j I ' I r ' i ' ! 1 , f j ! \ : I j I , ! ! --·r·~---1---i---l .L. --~ ·1 ·•·· · · ....... i ·i· r . I .L ~---i--·i--ewv• el ~-: -~~!-ui -!~-:··t .. : I ! l I . ' ) I I ' ' ' ' -·+ -;··•·! ---,-.J .. --. !9~-I.,~ I.,,• ' ,.,~, ~ ~ '"'" 'I •... :-... j · , , I 1 f ' . i , ! ~ . 1 "6iE \~/ti_/6f !WALL :Kr\\(<::, Go.···· ____ _j_ • . . . , I . :~ ; . . . ' ' , ·,· ---r· -~~@'t)·r"""\<tt·to:~-jo \''' /"•At· ·04 --L--· .... ~1.-... ~--~--\':'-!, L ~ v..r~ ~~~ .~ . __ ~ C J, -·---1 ... ' ' --1.. . ..... -! -· i.. Miles Consulting PO Box· 40143 Bellevue, WA 98015 . ' profec;t loclllon · c;11tnt fFUECIE~VIED ncr f Ii 2004 · ., .. KING COUNTY LAND USE SERVICES . } . ; .. checked date ·--\ ·- ··( . Design loads are for the actual dead loads,. soils loads as determined from the Civil Engineering·Plans and an HS20 vehicle AASHTO distributed. Construction should be in acciordance with latest edition of UBC and inspection should include; ' 1. All concrete work phases and strength. . 2. Provide special.inspection by Geotechnical Engineer confirming assumed soils parameters. 3. Any fill placed below footings or slab has sufficient ooll)paotion to.at least 95% ASTM D-1557. Prior to excavation the Contractor will determine if any· underground utilities exist in the area of work. -foundations have. been desi·gnE!d based on; Allowable Bearing '2.~00 PSF I // · Active Earth Pressure . ~ PCF (Ret·aining) Active Earth Pressure 5:0 ;PcF (R4;1s_tra.lned) Passive Earth Pressure 300' PCF · Soil Wt 120 PCF Coef. of Friction .4 (SF= 1.5) . . . Foundation exoavat.ion · shall extend into undisturbed soil. If.filling shoul(J occur it will. be place to 95% compaction and shall be.inspected for adequacy per ASTM D-1557. Back-filling of the walls shall be accomplished using a free draining material. When required, a· sub-drain should be installed to carry away any local ground wat'er which might accumulate. in th.e back-fill or pond· behind wall. Raise fill evenly around tank to prevent overlo~ding walls at any specific .point. · Concrete construction· for oast-in~plaoe ·concrete shall. be. inspected and tested. The concrete sh~ll attain a·minimum 28 day strength of fa'= 3000 psi. Use of add mixtures shall have OWner approval. (Strength required to back-fill.) Provide forms ·and falsework as ·required for construction. Reinforcing steel shall.conform to ASTM A..;615-68, Grade 60. Lap splices shall be a minimum of 30 bar diameters. Fy= 60,000 psi. All horizontal reinforcing bar·s in walls shall be lapped around the corners.. The reinforcing s_hall be protected by minimum cover as detailed on the plans, or when not detailed per UBC Concrete Construction. · I . TO[ 469.2 •' ·-'-' l-~- ·--, 'L ····-. ;.,- ·~~:-. J -/,--.;: .. k-,,,5, ·-~-<:.!·-·::c·j'" 1. ··. -. ~- ' STA. 0+5dF.G. TOP 479.6 , , · . . TOE 469.J' STA. 1 +odfF. c. TOR 484. o -. · TOE 471'' CONCR(lE RETAINING WALL, BY. 0 llj_f_RS \ "-'<.fJVtlnt•'71...'\.IV VL.I '-''-' \ \ STA. L. ., ('C. TOP 490. 0 f ' \[OE 480.2 -• ' •• -• --1 ---. END CONCRElE WALL BEGIN ROCKERY $TA. 2+50 F.G. TOP 492.0 TOP 492.5 F. G. 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ESC ANALYSIS AND DESIGN: Design of the erosion/sedimentation control plan was completed in conformance with Core Requirement #5 per the 1998 KCSWDM. Compliance with the 7 minimum requirements are summarized below. I. Clearing Limits: Clearing limits have been delineated on sheet C2.0I of the civil plans. The clearing limits extend only to those areas that will be disturbed during construction of the subject project. 2. Cover Measures: The Construction Sequence listed on sheet C2.0I of the civil plans specify specific times at which temporary and permanent cover measures will be installed. 3. Perimeter Protection: Per sheet C2.01 of the civil plans, silt fence will be used for perimeter protection. Silt fence will be installed along the perimeters of those areas that will be receiving silt-laden runoff. 4. Traffic Area Stabilization: A construction entrance will be installed. See sheets C2.0I and C2.31 for location of construction entrance and detail. 5. Sediment Retention: The wetpond will be used for sediment retention. Sediment retention will be designed per the 1998 KCSWDM Appendix D. Surface Area: East Basin Q2 (posteast.tsf) = 1.94 cfs SA= 2080 sf/cfs * Q2 SA= 2080 sf/cfs * 1.94 cfs = 4,035 SF Available Wetpond SA (Elev. 458.5) = 120'x35'=4,200 SF> 4,035 SF=> OK Riser Diameter: The riser diameter will be 18". Emergency Overflow Spillway: The emergency overflow spillway as designed in Section 4B of this report will be installed as part of the erosion/sedimentation ponds. Dewatering Orifice: A,= A,(2h)°5/(0.6*3600Tg05) D = 24(A,,/3.14)05 Pond A,= 4,200(2*2.0)05/(0.6*3600*24*32.2°5 ) = 0.029 SF Pond D = 24(0.029/3.14)05 = 2.31" Use 2-3/8" 6. Surface Water Control: Interceptor swales will be used to direct all sediment- laden runoff to the sediment retention facility. See sheets C2.0l and C2.31 for location of swales and details. 7. Dust Control: A note on sheet C2.0l addresses the procedure for dust control should soils become too dry. 9. BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT: The bond quantities worksheet and facility summaries will be completed upon engineering plan approval. A Declaration of Covenant will be completed prior to engineering plan approval. Site Improvement Bond Quantity Worksheet @ King County Department of Development & Environmental Services 900 Oakesdale Avenue Southwest Renton, Washington 98055-1219 206-296-6600 TTY 206-296-7217 Project Name: Plat of Evendell Location: SE 136th St & 157th Ave SE Clearing greater than or equal to 5,000 board feet of timber? X yes If yes, Forest Practice Perm~ Number: (RCW76.09) Page 1 of 9 no L04GF042 For alternate formats, call 206-296-6600. Date: 10-Nov-04 Project No.: t...ol Po-v tb Activity No.: LrJ I f"rJrJ 16Afl93RE838 Lo4-SRo2.f Note: All prices include labor, equipment, materials, overhead and profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database. R,uffe"'~dd r t2ffY~ ~~7 11 /3o/ZD01 040098QW03.xls Check out the DDES Web site at www.metrokc.gov/ddes Unit prices updated: 02/12/02 Version: 04/22/02 Report Date: 11/30/2004 Site Improvement Bond Quantity Worksheet EROSiON/SEDIMENT coNXROlli} { Backfill & compaction-embankment Check dams, 4" minus rock Crushed surfacing 1 1/4" minus Ditching Excavation-bulk Fence, silt Fence, Temporary (NGPE) Hydroseeding Jute Mesh Mulch, by hand, straw, 3" deep Mulch, by machine, straw, 2" deep Piping, temporary, CPP, 6" Piping, temporary, CPP, 8" Piping, temporary, CPP, 12" Plastic covering, 6mm thick, sandbagged Rip Rap, machine placed; slopes Rock Construction Entrance, 50'x15'x1' Rock Construction Entrance, 100'x15'x1' Sediment pond riser assembly Sediment trap, 5' high berm Sed. trap, 5' high, riprapped spillway berm section Seeding, by hand Sodding, 1" deep, level ground Sodding, 1" deep, sloped ground TESC Supervisor Water truck, dust control WRJT:E4N4TEMS1!!M{seeRii9iiir9I J r ' Concrete Vault Page 2 of 9 04009BQW03.xls ESC-1 ESC-2 SWDM 54.6.3 ESC-3 WSDOT 9-03.9(3) ESC-4 ESC-5 ESC-6 SWDM 54. 3.1 ESC-7 ESC-8 SWDM 5.4.2.4 ESC-9 SWDM 5.4.2.2 ESC-10 SWDM 54.2.1 ESC-11 SWDM 5.4.2.1 ESC-12 ESC-13 ESC-14 ESC-15 SWDM 5.4.2.3 ESC-16 WSDOT 9-13.1(2) ESC-17 SWDM 5.44.1 ESC-18 SWDM 5.4.4.1 ESC-19 SWDM54.5.2 ESC-20 SWDM 5.4.5.1 ESC-21 SWDM 54.5.1 ESC-22 SWDM 5.4.2.4 ESC-23 SWDM 5.4.2.5 ESC-24 SWDM 5.4.2.5 ESC-25 ESC-26 SWDM 5.4.7 I $ 5.62 CY 1 150001 $ 67.51 Each I 161 $ 85.45 CY $ 808 CY 275 $ 1.50 CY 15000 $ 1.38 LF 2400 $ 1.38 LF $ 0.59 SY $ 1.45 SY $ 2.01 SY $ 0.53 SY I 500001 $ 10.70 LF $ 16.10 LF $ 20.70 LF I 2001 $ 2.30 SY $ 39.08 CY I 51 $ 1,464.34 Each $ 2,928.68 Each 1 11 $ 1,949.38 Each I 11 $ 17.91 LF $ 68.54 LF $ 0.51 SY $ 6.03 SY $ 7.45 SY $ 74.75 HR I 101 $ I $120.000.00 I Each I 11 ESC SUBTOTAL:. 30% CONTINGENCY & MOBILIZATION: ESCTOTAL: COLUMN: Check out the DDES Web site at www.metrokc.gov/ddes 11 11 1 1 1 1 1 I 11 11 11 11 1 1 I 84300 1080 2222 22500 3312 26500 4140 195 29291 19491 120000 $ 270,852.62 $ 81,255.79 $ 352,108.41 A Unit prices updated: 02/12/02 Version: 04/22/02 Report Date: 11/30/2004 Site Improvement B d Quantity Worksheet Backfill & Compaction-embankment GI -1 $ 5.62 Backfill & Compaction-trench GI -2 $ 8.53 Clear/Remove Brush, by hand GI -3 $ 0.36 Clearing/Grubbing/Tree Removal Gl-4 $ 8,876.16 Excavation -bulk GI -5 $ 1.50 Excavation -Trench Gl-6 $ 4.06 Fencing, cedar, 6' high GI -7 $ 18.55 Fencing, chain link, vinyl coated, 6' hig GI -8 $ 13.44 Fencing, chain link, gate, vinyl coated, 2 Gl-9 $ 1,271.81 Fencing, split rail, 3' high GI -1 $ 12.12 Fill & compact -common barrow GI -11 $ 22.57 Fill & compact -gravel base GI -1, $ 25.48 Fill & compact -screened topsoil GI -11 $ 37.85 Gabion, 12" deep, stone filled mesh GI -14 $ 54.31 Gabion, 18" deep, stone filled mesh GI-H $ 74.85 Gabion, 36" deep, stone filled mesh GI -1E $ 132.48 Grading, fine, by hand GI -1 $ 2.02 Grading, fine, with grader GI -1! $ 0.95 Monuments, 3' long GI-H $ 135.13 Sensitive Areas Sign GI -20 $ 2.88 Sodding, 1" deep, sloped ground GI -21 $ 7.46 Surveying, line & grade GI ·2~ $ 788.26 Surveying, lot location/lines GI -2, $ 1,556.64 Traffic control crew ( 2 flaggers) GI -24 $ 85.18 Trail, 4" chipped wood GI -2~ $ 7.59 Trail, 4" crushed cinder GI -2E $ 8.33 Trail, 4" top course GI -2 $ 8.19 Wall, retaining, concrete GI -2 $ 44.16 Wall, rockery GI -21 $ 9.49 Page3of9 SUBTOTAL .. KCC 27 A authorizes only one bond reduction. 04009BQW03.xls CY I I I 20001 11,240.001 150001 CY j 35oJ. 2,985.5oj 6001 5,118 oq]_ 105qt SY Acre 2 17,752.32 2 17,752.321 9j CY 5750 8,625.001 CY 400 1,624.00 650 2,639.ool 11501 LF LF Each LF CY CY CY SY SY SY SY SY Each I 51 675.651 121 1,621.56 Each SY Day I i I 788.261 21 1,576.521 11 Acre HR SY SY SY SF T 2,sooT 11 o,400.ooT SF 11251 10,676.25 144,901.98 -~572.40 Check out the DDES Web site at www_metrokc_qovlddes 84,300.00 -~956.50 79,885.44 4,669.00 788.26 178,599.20 Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement B ' . .d Quantity Worksheet ·····•tt{fi@t{!'.®Ji§ ROAOIMPROVEMENt\t·••J••••··········· AC Grinding, 4' wide machine < 1 OOOs AC Grindirig, 4' wide machine 1000-200f RI -2 $ 5.75 SY AC Grinding, 4' wide machine > 2000s RI -3 $ 1.38 SY AC Removal/Disposal/Repair RI -4 $ 41.14 SY Barricade, type I RI -5 $ 30.03 LF Barricade, type Ill ( Permanent) RI -6 $ 45.05 LF Curb & Gutter, rolled RI -7 $ 13.27 LF I I I 3300\ 43,791.00 Curb & Gutter, vertical RI -8 $ 9.69 LF l 25001 24,225.ool Curb and Gutter, demolition and dispos RI -9 $ 13.58 LF Curb, extruded asphalt RI -10 $ 2.44 LF RI -11 $ 2.56 LF RI -1~ $ 1.85 LF Sawcut, concrete, oer 1" death Rl-13 $ 1.69 LF Sealant, asphalt RI -14 $ 0.99 LF Shoulder, AC, ( see AC road unit price 1'1-H $ . SY Shoulder, gravel, 4" thick RI -1€ $ 7.53 SY Sidewalk, 4" thick RI -1i $ 30.52 SY I 11001 33,572.001 9251 2!3,231.00 Sidewalk, 4" thick, demolition and disnns RI -1: $ 27.73 SY Sidewalk, 5" thick Rl-19 $ 34.94 SY Sidewalk, 5" thick, demolition and dispos RI -20 $ 34.65 SY Sign, handiCap RI -21 $ 85.28 Each Striping, per stall RI -2 $ 5.82 Each Striping, thermoplastic, ( for crosswalk RI -2: $ 2.38 SF I 1201 285.60\ I I 50\ Striping, 4" reflectorized line RI -24 $ 0.25 LF I 5600\ 1,400.00 Page4of9 SUBTOTAL 59,482.60 72,022.00 *KCC 27 A authorizes only one bond reduction. 04009BOW03.xls Check out the ODES Web site at www.metrokc.gov/cldes 119.00 119.00 Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement B ,d Quantity Worksheet For KCRS '93, (additional 2.5" base) add RS -1 $ 3.60 AC Overlay, 1.5" AC RS -2 $ 7.39 AC Overlay, 2" AC RS-3 $ 8.75 AC Raad, 2", 4" rock, First 2500 SY RS-4 $ 17.24 AC Road, 2", 4" rock, Oty. over 2500S RS-5 $ 13.36 AC Road, 3", 4" rock, First 2500 SY RS-6 $ 19.69 AC Road, 3", 4 .. rock, Qty. over 2500 S !RS -7 $ 15.81 AC Road, 5 .. , First 2500 SY RS-8 $ 14.57 AC Road, 5", Qty. Over 2500 SY RS-9 $ 13.94 AC Road, 6", First 2500 SY RS -1( $ 16.76 AC Road, 6", Qty. Over 2500 SY RS -1 1 $ 16.12 Asphalt Treated Base, 4" thick <S-1 $ 9.21 Gravel Road, 4" rock, First 2500 SY ,5 .1 $ 11.41 Gravel Road, 4" rock, Qty. over 2500 S RS-1• $ 7.53 PCC Road, 5", no base, over 2500 SY RS-11 $ 21.51 PCC Road, 6", no base, over 2500 SY RS-11 $ 21.87 Thickened Edge RS -1· $ 6.89 Page5of9 SUBTOTAL "KCC 27 A authorizes only one bond reduction. 04009BQW03.xls I1il11111I••••• SY I 35001 12,600.001 27701 9,972.00\ 14501 SY SY SY 25001 43,100.001 1450\ SY 27oJ. __ 3,607.201 SY 2500 49,225.00 SY 1000 15,810.00 SY SY SY SY SY SY SY SY SY LF t t T T 1 6401 77,635.00 -~.679.20 Check out the DOES Web site atwww.metrokc.gov/ddes 5,220.00 24,998.00 4,409.soi 34,627.60 Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement B .d Quantity Worksheet bMlNAGe 1¢\:i!Jiili~~liii ili~i;iii; ifa¥: M?~i~~i4~ii i iit;B&&~Ui&J! i;w~&.~i~;;:;;;;;;;;;;;.;~;;;~~;;;;;;;;;;;wlt\;id~£;;;;~ J;;;;;;;;; ihi1ii~;,;;;;i AccessRoad,R/D .... J D-1 J $ 16.74 J SY J I I J I J J I Bollards -removable I D -3 I $ 452.34 I Each 481.481 I I 452.34 Bollards -fixed I D -2 I $ 240.74 I Each I 2 * (CBs include frame and lid) 257.64 CBTypel ID-41$1,r-Each 15,091.68 22 27,668.08 CB Type IL D-5 $ 1,433.59 Each CB Type II, 48" diameter D-6 $ 2,033.57 Each 8 16,268.56 9 18,302.13 for additional de.e_th over 4' D-7 $ 436.52 FT 29 12,659.08 9 3,928.68 CB Type II, 54" diameter D-8 $ 2,192.64 Each for additionat de_e_th over 4' D-9 $ 486.53 FT CB Type II, 60" diameter D-10 $ 2,351.52 Each 1 2,351.52' for additional depth over 4' D -11 $ 536.54 FT 536.54 -D-12 $ 3,212.64 Each CB Type_J_L_ 72" diameter -D-13 $ 692.21 FT for additional de.e_th over 4' 1,098.27 -, D -14 $ 366.09 Each D-15 $ 130.55 Each Throu~h-curb Inlet Framework (Add) Cleanout, PVC, 4" 3 ' Cleanout.!. PVC, 6" D-16 $ 174.90 Each Cleanout, PVC, 8" D-17 $ 224.19 Each Culvert. PVC, 4" D-18 $ 8.64 LF Culvert, PV9, 6" D-19 $ 12.60 LF Culvert, PV_C, 8" D-20 $ 13.33 LF Culvert, PVC, 12" D-21 $ 21.77 LF Culvert, CMP, 8" D-22 $ 17.25 LF Culvert! CMP, 12" D-23 $ 26.45 LF Culvert,~~£'! 15" D-24 $ 32.73 LF Culvert, CMP, 18" D-25 $ 37.74 LF Culvert, C_~P ~ 24" D-26 $ 53.33 LF Culvert, CMP, 30" D -27 $ 71.45 LF Culvert, C~~. 36" D -28 $ 112.11 LF Culvert, CMP, 48" D -29 $ 140.83 LF Culvert! CMP, 60" D-30 $ 235.45 LF Culvert, CMP, 72" D-31 $ 302.58 LF Page 6 of9 SUBTOTAL 46,587.95 52,250.41 *KCC 27 A authorizes only one bond reduction. 04009BOW03.xls Check out the DOES Web site at www.metrokc.gov/ddes 2 2 11 3 17 53 481.48 904.68 13,834.04 6,100.71 7,420.84 2,351.52 9,269.70 40,362.97 Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement B .d Quantity Worksheet Culvert, Concrete, 8" D • 32 $ 21.02 Culvert, Concrete, 12" D-33 $ 30.05 Culvert, Concrete, 15" D -34 $ 37.34 Culvert, Concrete, 18" D -35 $ 44.51 Culvert, Concrete, 24" D -36 $ 61.07 Culvert, Concrete, 30" D -37 $ 104.18 Culvert, Concrete, 36" D -38 $ 137.63 Culvert, Concrete, 42" D-39 $ 158.42 Culvert, Concrete, 48" D -40 $ 175.94 Culvert, CPP, 6" D -41 $ 10.70 Culvert, CPP, 8" D-42 $ 16.10 Culvert, CPP, 12" D -43 $ 20.70 Culvert, CPP, 15" D-44 $ 23.00 Culvert, CPP, 18" D-45 $ 27.60 Culvert, CPP, 24" D-46 $ 36.80 Culvert, CPP, 30" D-47 $ 48.30 Culvert, CPP, 36" D-48 $ 55.20 Ditching D-49 $ 8.08 Flow Dispersal Trench (1,436 base+) D -50 $ 25.99 French Drain (3' depth) D • 51 $ 22.60 Geotextile, laid in trench, polvpropylem D -52 $ 2.40 Infiltration pond testing D -53 $ 74.75 Mid.tank Access Riser, 48" dia, .6' dee D-54 $ 1,605.40 Pond Overflow Spillway D-55 $ 14.01 Restrictor/Oil Separator, 12" D • 56 $ 1,045.19 Restrictor/Oil Separator, 15" D -57 $ 1,095.56 Restrictor/Oil Separator, 18" D -58 $ 1,146.16 Riprap, placed D • 59 $ 39.08 Tank End Reducer (36" diameter) D-60 $ 1,000.50 Trash Rack, 12" D-61 $ 211.97 1Trash Rack, 15" D-62 $ 237.27 Trash Rack, 18" D -63 $ 268.89 [Trash Rack, 21" D-64 $ 306.84 Page 7 of9 SUBTOTAL ·KCC 27A authorizes only one bond reduction. 04009BQW03.xls LF LF LF LF LF LF LF LF LF LF LF LF ·1 51a] LF I 501 LF LF I 5891 LF LF CY I 501 LF LF SY HR Each SY Each Each Each CY Each Each Each Each Each Jrnrra1t~mgmt~1f]JI1It ...... . ••••·t•·•·•fg~!ml/mYm\iimlf I••• ····•·ttiraiiiiigl/,fi.icmt;_.,, > • =?:94~6W+ 10722.sl 2181 45146.7 11501 73 1679 21675.2 404 33951.8 46825.7 Check out the DOES Web site atwww.metrokc.gov/ddes 2700 935 165 50 28890 19354.5 4554 700.5 1146.16 268.89 54914.05 Unit prices updated• 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement B .d Quantity Worksheet No. 2" AC, 2" top course rock & 4" borrow PL -1 $ 15.84 SY 2" AC, 1.5" top course & 2.5" base cou PL-2 $ 17.24 SY 4" select borrow PL -3 $ 4.55 SY 1.5" top course rock & 2.5" base coursE PL -4 $ 11.41 SY rteJWJ:ti:MS@t•••' n nr t l(Such as detention/water quality vaults. No. !School Walkway WI -1 Each Concrete Sidewalk Wl-2 $ 30.52 SY Grading Wl-3 $ 5,000.00 LS Concrete Stairs Wl-4 $ 5,000.00 LS Metal Handrail Wl-5 $ 50.00 FT Wl-6 Wl-7 Wl-8 Wl-9 Wl-10 SUBTOTAL SUBTOTAL (SUM ALL PAGES): 30% CONTINGENCY & MOBILIZATION: GRANDTOTAL: COLUMN: Page 8 of9 I 140 4272.8 500 15,260.00' 5,000.00 4,272.80 20,260.00 366,832.13 v 296,609.71 ,- 110,049.64 88,982.91 476,881.77 385,592.62 _,, B C *KCC 27 A authorizes only one bond reduction. 04009BQW03.xls Check out the ODES Web site at www.metrokc.gov/ddes 50 60 1,526.00 5,000.00 3,000.00 9,526.00 318,148.82-/ 95,444.65 413,593.47 ,/ D E Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: Plat of Evendell Date: 1 O-Nov-04 PE Registration Number: 33713 Tel.#: 425-885-7877 Firm Name: Address: Core Desi_g_n, Inc. 14711 NE 29th Place, Suite #101 Project No: LO IF OOib ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND· AMOUNT Stabilization/Erosion Sediment Control (ESC} (A) $ 352.108.4 Existing Right-of-Way Improvements · (8) $ 476,881.8 Future Public Road Improvements & Drainage Facilities (C) $ 385,592.6 Private Improvements (D) $ 413,593.5 Calculated Quantity Completed Total Right-of Way and/or Site Restoration Bond•r (First $7,500 of bond· shall be cash.) (A+B) $ 828,990.2 Performance Bond• Amount (A+B+C+D) =. TOTAL Reduced Performance Bond* Total*** Maintenance/Defect Bond• Total (T) $ 1,628,176.3 Minimum bond" amount is $1000. BOND.AMOUNT REQUIRED AT RECORDING OR TEMPORARY OCCUPANCY ••• (E) $ TX 0.30 $ 488,452.9 (T-E) $ 1,628,176.3 Use larger of 1 x30% or { 1-E) OR NAME OF PERSON PREPARING BOND• REDUCTION: Date: * NOTE: The word "bond" as used in this document means any financial guarantee acceptable to King County. "'* NOTE: KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. PUBLIC ROAD & DRAINAGE MAINTENANCE/DEFECT BOND• (B+C) x 0.25 = $ 215,618.6 The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on-and off-site needs to be included. Quantities shatl reflect worse case scenarios not just minimum requirements. For example, if a salmon id stream may be damaged, some estimated costs for restoration needs to be reflected in this amount. The 30% contingency and mobilizatior:, costs are computed in this quantity. -NOTE: Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes. SURETY BOND RIDER NOTE: If a bond rider is used. minimum additional performance bond shall be ! $ 799,186.1 !(C+D)-E REQUIRED BOND' AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DOES Page 9 of 9 04009BQW03.xls Check out the DDES Web site at www.metrol<c.gov/ddes Unit prices updated: 02/12/02 Version: 4/22/02 Report Date: 11/30/2004 V 10. OPERATIONS AND MAINTENANCE MANUAL: A maintenance and operations manual is not required since all drainage facilities will be public.