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HomeMy WebLinkAboutSWP272975 ' DRAINAGE REPORT AND LEVEL 1 DOWNSTREAM ANALYSIS Proposed ARCO AM/PM Facility ' - South and Rainier Avenue North NWC Renton Avenue ' Renton, Washington 1 Prepared for: 1 2.-7--o2, Atlantic Richfield Company ,I JACOed' 4 Centerpointe Drive La Palma, California 90623-1066 1 t ' June 22, 2001 EXPIRE Revised: February 7, 2002 ' Our Job No. 7816 1 CITY OF PENTON RECEIVED MAR 0 4 2002 ' BUILDING DIVISION CIVIL ENGINEERING, LAND PLANNING,SURVEYING, ENVIRONMENTAL SERVICES 18215 72ND AVENUE SOUTH, KENT,WA 98032 . (425)251-6222 . (425)251-8782 FAx u www.barghausen.com 0 �0",� r S y, DRAINAGE REPORT AND LEVEL 1 DOWNSTREAM ANALYSIS Proposed ARCO AM/PM Facility NWC - Renton Avenue South and Rainier Avenue North 1 Renton, Washington ' Prepared for: 2-�--o 2. Atlantic Richfield Company �o���5 °es 4 Centerpointe Drive hl La Palma, California `- 90623-1066 1 r June 22, 2001 EY.PIiRE3 Revised: February 7, 2002 Our Job No. 7816 1 CIVIL ENGINEERING, LAND PLANNING,SURVEYING, ENVIRONMENTAL SERVICES _ 18215 72ND AVENUE SOUTH, KENT,WA 98032 . (425)251-6222 . (425)251-8782 FAX sue , www.barghausen.com �?tNG rNGttt��v ' TABLE OF CONTENTS 1.0 INTRODUCTION AND GENERAL INFORMATION 2.0 ANALYSIS OF THE SEVEN CORE REQUIREMENTS 3.0 ANALYSIS OF THE TWELVE SPECIAL REQUIREMENTS APPENDIX APPENDIX"A" TECHNICAL INFORMATION REPORT WORKSHEET APPENDIX"B" WATER QUALITY AND FLOW CONTROL CALCULATIONS ' APPENDIX"C" LEVEL I DOWNSTREAM ANALYSIS 1.0 INTRODUCTION AND GENERAL INFORMATION 1 1 1 1 1 1 1 1 ' 1.0 INTRODUCTION AND GENERAL INFORMATION ' The proposed ARCO AM/PM facility is located in the Northeast quarter of the Northwest quarter of Section 18,Township 23 North,Range 5 East,Willamette Meridian,City of Renton,King County,State of Washington, more particularly described as located on the northwest corner of the Renton Avenue extension and Rainier Avenue North. See the enclosed Vicinity Map(Exhibit"A")within Appendix"C" of this report,the Level 1 Downstream Analysis. ' The existing topography of the site is flat in nature,with a fairly constant slope of 3 to 4 percent from the northwest to the southeast corner of the site. The site is currently covered with tall grass over the entire site and was previously developed;however,all evidence of previous structures is nonexistent. The site ' currently sheetflows into a catch basin and pipe conveyance system that collects runoff along the southern property line and conveys it into a 48-inch diameter pipe system in the Renton Avenue extension. When developed,the site will discharge into the same collection system after runoff is routed to the proposed ' water quality and detention facilities near the eastern property line of the site. This project proposes improvements to Hardie Avenue N.W. which forms its western boundary on the project site. The northern boundary of the site is an existing one-story building, currently fully developed. The improvements proposed for Hardie Avenue N.W. are the inclusion of curb, gutter, and sidewalk along the eastern side of the street which forms the western right-of-way of the site. The runoff ' from these improvements will be routed into a collection and conveyance system, located in Hardie Avenue N.W., which will ultimately discharge to the same 48-inch diameter culvert in Renton Avenue South that the site does. The development of this project site will be in accordance with the 1990 King County, Washington Surface Water Design Manual, as modified by the City of Renton requirements. ' In particular,detention will be sized to match the 2-year and 10-year pre-developed to the corresponding post-developed 24-hour storm events and then routing the 100-year post-developed 24-hour storm event through the detention system after it has been increased in size by 30 percent to determine an actual ' performance standard for the site. In lieu of biofiltration, the site proposes to install a combined wet/detention vault with water quality and dead storage in the vault below the live storage, which was sized to the requirements of the 1990 King County, Washington Surface Water Design Manual so that one third of the precipitation value for the 2-year storm developed site hydrograph was determined yielding a volume that will be stored as dead storage in the combined wet/detention vault. This site does not create more than one acre of new impervious surface subject to vehicular traffic. Therefore,the water ' quality portion of the project is not required to be upsized by 150 percent. ' 7816.010 [JPJ/ath/rh] ' 2.0 ANALYSIS OF THE SEVEN CORE REQUIREMENTS 1 1 1 1 1 1 1 ' 2.0 ANALYSIS OF THE SEVEN CORE REQUIREMENTS Core Requirement No.1-Discharge at the Natural Location: The discharge from a proposed project site must occur at the natural location. Response: This project proposes discharge at the natural location in accordance with Core Requirement No. 1. No diversion of runoff will be allowed at the development of this project. Core Requirement No. 2 - Off-Site Analysis: All proposed projects must identify the upstream tributary drainage area and perform a downstream analysis. Levels of analysis required depend on the problems identified or predicted. At a minimum a Level I Analysis must be submitted with the initial ' permit application. Response: This drainage report incorporates a Level 1 Downstream Analysis as Appendix"C." Please refer to that document for fulfillment of this requirement. Core Requirement No.3-Flow Control: Proposed projects must provide runoff controls to limit the developed conditions,peak rates of runoff to the pre-development of peak rates for specific design storm events based on the runoff from defined existing site conditions and install biofiltration measures. Response: This project proposes to provide detention in accordance with the 1990 King County, Washington Surface Water Design Manual,which matches the 2-year and 10-year/24-hour pre-developed peak runoff rates to the 2-year and 10-year/24-hour post-developed design storm,increasing the detention volume by 30 percent and routing the 100-year developed condition 24-hour design storm through the ' upsized detention system. This project proposes a wet/detention vault as a means of runoff treatment. Core Requirement No.4- Conveyance System: All conveyance systems for proposed projects must ' be analyzed, designed and constructed for existing tributary off-site runoff and developed on-site runoff from the proposed project. Response: This project proposes for new pipe systems to be designed to sufficient capacity to convey and contain at a minimum the 25-year peak flow assuming developed conditions for on-site conditions for tributary areas and existing conditions for any off-site tributary areas all in accordance with the 1990 King County, Washington Surface Water Design Manual. Core Requirement No.5-Temporary Erosion and Sedimentation Control: All projects that require engineered drainage plans shall provide temporary erosion and sedimentation control measures that minimize the transport of sediment to drainage facilities, water resources and adjacent properties. Response: This project proposes to prevent the transport of sediment to streams, wetlands, lakes,and adjacent properties using the methods described in the 1990 King County, Washington Surface Water Design Manual, including establishing clearing limits, cover measures, and providing perimeter ' protection in the form of silt fences. In addition,traffic area stabilization will be constructed in the form of rock construction entrances, and the proposed wet/detention vault will be the first order of construction, so that all on-site runoff will be routed through it prior to discharge of runoff from the site during construction. ' 7816.010 [JPJ/ath/rh] ' Core Requirement No. 6 - Maintenance and Operations: q p Maintenance of all drainage facilities ' constructed or modified by a proposed project is the responsibility of the property owner,except the City of Renton may assume maintenance of drainage facilities constructed for formal plat subdivisions, planned unit developments, and some short plat subdivisions two years after construction approval. Response: All drainage facilities,including catch basins and conveyance systems,detention and water quality facilities will be located on site, except for those constructed in Hardie Avenue N.W. Those constructed in Hardie Avenue N.W.will be maintained in perpetuity by the City of Renton. All on-site ' facilities will be maintained by the property owner and a maintenance operations manual will be prepared for their use. ' Core Requirement No.7-Bonds and Liability: All drainage facilities for the proposed projects must be constructed in conformance with the bond and liability requirements of the City of Renton. ' Response: This project concurs with all bonds and liability requirements as dictated by the City of Renton. 7816.010 [JPJ/ath/rhl 1 3.0 ANALYSIS OF THE TWELVE SPECIAL REQUIREMENTS 1 1 1 1 1 1 1 3.0 ANALYSIS OF THE TWELVE PE S CIAL REQUIREMENTS Special Requirement No. 1-Critical Drainage Areas: If a proposed project lies within a designated critical drainage area as indicated on critical drainage area maps, then the proposed project drainage review and engineering plans shall be prepared in accordance with the special critical drainage area requirements that have been formally adopted by public rule. Response: The proposed project site does not lie within a critical drainage area. Special Requirement No. 2 - Compliance with an Existing Master Drainage Plan: If a proposed project lies within an area covered by an approved master drainage plan as listed at the City of Renton Division Permit center, then the proposed projects drainage review and engineering plan shall be prepared in accordance with any special requirements of the master drainage plan. Response: The project site does not lie with an existing master drainage plan. Special Requirement No.3-Conditions Requiring a Master Drainage Plan: If a proposed project is a master plan development as described in an adopted community plan or is a subdivision or planned unit development that will eventually have more than 100 single family residential lots or is a commercial development or planned unit development that will eventually construct more than 50 acres of impervious surface or will clear an area of more than 500 acres within a contiguous drainage area subbasin, then a master drainage plan must be prepared. Response: This site does not meet any of the conditions requiring a master drainage plan. Special Requirement No.4-Adopted Basin and Community Plans: If a proposed project lies within an area with an adopted basin or community plan as listed at the City of Renton Permit Center, then the proposed project drainage review and engineering plan shall be prepared in conformance with the special requirements of the adopted basin plan or community plan. Response: This project site does not lie within an adopted basin or community plan area. Special Requirement No.5-Special Water Quality Controls:If any threshold area of the proposed project contains more than one acre of new impervious surface that will be subject to vehicular use or storage of chemicals and proposes direct discharge of runoff to regional facilities, receiving water,lake, wetland or closed depression without on-site peak rate runoff control or proposes discharge of runoff ' through overland flow or on-site infiltration into a Class 1 or 2 stream or a Class 1 wetland within a one mile radius downstream from the project site, then the threshold discharge area shall have a wet pond meeting the standards of the City of Renton employed to treat a projects runoff prior to discharge from the site. Response: The proposed project site does not contain more than one acre of new impervious surface that will be subject to vehicular use or storage of chemicals, therefore, this requirement does not apply. However, this project is proposing a wet/detention vault of the methodology for stormwater quality treatment, therefore, it meets this requirement without necessarily having to. Special Requirement No. 6 - Coalescing Plate OH/Water Separator: If a proposed project will construct more than five acres of impervious surface in any threshold discharge area,that will be subject r7816.010 [JPJ/ath/rhl to petroleum storage or transfer,or high vehicular use g .f g ,or heavy equipment use storage or maintenance, then a coalescing plate or equivalent oiVwater separator shall be employed in the threshold discharge area to treat the project's runoff prior to treatment by a wet pond, wet vault or water quality swale. Response: This project does not meet the threshold of this requirement,therefore, no coalescing plate oil/water separator is required. Special Requirement No. 7 - Closed Depression: If a proposed project will discharge runoff to an existing closed depression that has greater than 5,000 square feet of water surface area at overflow elevation, then the project must meet the requirement of closed depression. Response: This project does not discharge to a closed depression in any of its downstream drainage course. Special Requirement No.8-Use of Lakes,Wetlands or Closed Depressions for Peak Rate Runoff Control: If a project proposes to use a lake, wetland or closed depression for peak rate runoff control consistent with Core Requirement No. 3 or use a lake, wetland or closed depression to receive a direct discharge consistent with an exemption from Core Requirement No. 3 or increase the volume of runoff to an off-site closed depression, then the project must meet all the requirements of the sensitive areas ordinance and rules for such use and include water quality controls consistent with Special Requirement No.S and observe limits on any increases to the floodplain as described in the 1990 King County Surface Water Design Manual. Response: This project does not plan the use of a lake, wetland or closed depression for peak rate runoff control. Special Requirement No.9-Delineation of 100-year Flood Plain: If a proposed project contains or abuts a stream, lake, wetland or closed depression, or if other King County regulations require study of flood hazards, then the 100-year floodplain boundaries based on an approved flood hazard study as described in the 1990 King County Surface Water Design Manual shall be delineated on the site improvement plans and profiles and on any final subdivision maps prepared for the proposed development. Response: This project does not contain or abut a stream, lake, wetland or closed depression. Special Requirement No. 10-Flood Protection Facilities for Type 1 and 2 Streams: If a proposed project contains or abuts a Class l or 2 stream that has an existing flood protection facilities such as a levee, revetment or berm or proposes to construct or modify an existing flood protection facility, then the flood protection shall be analyzed and/or designed as described in the 1990 King County Surface Water Design Manual to demonstrate conformance with the Federal Emergency Management Administration Regulations. Response: This project does not contain or abut a Class I or H stream and is not proposing to modify an existing flood protection facility. Therefore, no flood protection facility needs to be analyzed and/or designed as described in the 1990 King County, Washington Surface Water Design Manual for this special requirement. 7816.010 [JPJ/adVrhl Special Requirement No.q Geotechmcal Analysis and Report: If a project proposes to construct a pond or an infiltration system within 200 feet from the top of the steep slope or on a slope with a gradient steeper than 15 percent or using a berm higher than 6 feet or modify existing flow protection facilities, then a geotechnical analysis and report shall be prepared and stamped by a geotechnical professional and civil engineer that shall address at minimum the analysis described in the 1990 King County Surface Water Design Manual. Response: This project does not meet any of the threshold requirements for this Special Requirement No. 11. Special Requirement No. 12-Soils Analysis and Report: If the soils underlying a proposed project have not been mapped or if the existing soil maps are in error of not a sufficient resolution to allow the proper engineering analysis of the proposed site to be performed, than a soils analysis and report shall be prepared and stamped by a professional civil engineer with expertise in soils to verify and/or map the ' underlying soils by addressing the minimum as described in the 1990 King County Surface Water Design Manual. Response: The soils report for this project is attached as Exhibit "I" in Appendix "C," the Level 1 Drainage Analysis. 7816.010 [JPJ/ath/rh] I 1 APPENDIX "A" TECHNICAL INFORMATION REPORT WORKSHEET 1 1 1 1 King County Department of Development and Environmental Services TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND PROJECT ENGINEER DESCRIPTION Project Owner Atlantic Richfield Company Project Name Address 4 Centerpointe Drive La Palma CA ARCO AM/PM and Car Wash Phone_(714) 670-5300 Location Project Engineer Jay Grubb Township 23 North Company Barghausen Consulting Engineers Inc Range 5 East Address/Phone 18215 - 72nd Avenue South NW Quarter Section 18 Kent, Washington 98032/ (425) 251-6222 Part 3 TYPE OF PERMIT Part 4 OTHER REVIEWS AND PERMITS APPLICATION ❑ Subdivision HPA ❑ DFW HPA ❑ Shoreline Management ❑ Short Subdivision ❑ COE 404 ❑ Rockery ❑ Grading ❑ DOE Dam Safety ■ Structural Vaults ■ Commercial ❑ FEMA Floodplain ❑ Other ❑ Other ❑ COE Wetlands Part 5 SITE COMMUNITY AND DRAINA GE BASIN Community City of Renton Drainage Basin Lake Washington Part 6 SITE CHARACTERISTICS ❑ River ❑ Floodplain ' ❑ Stream ❑ Wetlands ❑ Critical Stream Reach ❑ Seeps/Springs ❑ Depressions/Swales ❑ High Groundwater Table ❑ Lake ❑ Groundwater Recharge ❑ Steep Slopes ❑ Other i 7816c.012[JPJ/rh] Part 7 SOILS Soil Type Slopes Erosion Potential Erosive Velocities Beausite 3 to 4% Moderate ❑Additional Sheets Attached Part 8 DEVELOPMENT LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT ■Ch. 4 - Downstream Analysis ❑Additional Sheets Attached Part 9 ESC REQUIREMENTS QU REMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION ■ Sedimentation Facilities ■ Stabilize Exposed Surface ■ Stabilized Construction Entrance ■ Remove and Restore Temporary ESC Facilities ■ Perimeter Runoff Control ■ Clean and Remove all Silt and Debris 1 ❑ Clearing and Grading Restrictions ■ Ensure Operation of Permanent Facilities ■ Cover Practices ❑ Flag Limits of SAO and open space preservation ■ Construction Sequence areas ❑ Other ❑ Other Part 10 SURFACE WATER SYSTEM i ❑ Grass Lined Channel ❑ Tank ❑ Infiltration Method of Analysis ■ Pipe System ■ Vault ❑ Depression SBUH ❑ Open Channel ❑ Energy Dissipater ❑ Flow Dispersal Compensation/Mitigation ❑ Dry Pond ❑ Wetland ❑ Waiver of Eliminated Site Storage ❑ Wet Pond ❑ Stream ❑ Regional Detention Brief Description of System Operation Catch basin collection and pipe conveyance system to wet/detention vault with metered release. Facility Related Site Limitations Reference Facility Limitation 7816c.012[JPJ/rh] Part 11 STRUCTURAL ANALYSIS Part 12 EASEMENTS/TRACTS ■ Cast in Place Vault ❑ Drainage Easement ❑ Retaining Wall ❑ Access Easement ❑ Rockery>4' High ❑ Native Growth Protection Easement ❑ Structural on Steep Slope ❑ Tract ❑ Other ❑ Other Part 13 SIGNATURE OF PROFESSIONAL ENGINEER 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 attachments. To the best of my knowledge the information provided here is accurate. ' o 01 Signed/Date 7916.012[JPJ/rhl T 1 1 APPENDIX °B" WATER QUALITY AND FLOW CONTROL CALCULATIONS 1 6 14 01 4 : 4 : 23/ / pm Shareware Release page 1 ARCO-NWC OF RAINIER AVE AND RENTON AVE JOB NO . 7816 WORKS4 FILE NO. 7816 .BSN ----------------------------------------------------------- BASIN SUMMARY BASIN ID: WQDEV NAME : 1/3 2 YR PRECIP. W.Q. DEV SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 0 . 67 inches AREA. . : 0 . 38 Acres 0 . 89 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 TC. . . . : 7 . 96 min 7 . 96 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L : 55 . 00 ns : 0 . 1500 p2yr: 2 . 00 s : 0 . 0360 TcReach - Shallow L: 120 . 00 ks : 27 . 00 s : 0 . 0050 TcReach - Channel L : 150 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE : 0 . 10 cfs VOL: 0 . 04 Ac-ft TIME : 480 min r r r r r r 53' / TAX LOT. . i)"(143CC° _ '• o OD Z u; i,IOR AVE.It ,% I SURVEY INFORMATION 2 `. Ea D CH0 .,39AO > I I PROCEDURE/NARRATIVE O 2 f / c K e F 12'ULC N.38,47 % } y A FIELD TRAVERSE USING A SOKKLA 3100"TOTAL STATION,AND^SDR-33'DATA V _ COLA-ECfOR SUPPLEMENTED WITH FE1D NOTES WAS PERFORMED.ESTABLISHING W W OD ` ; 1 )-. - YMCA ENC�NQn o `1 THE ANGULAR, DISTANCE.AND VERTICAL RELATIONSHIPS BETWEEN THE MONUMENTS, • 6 m+ PAIiEI./ BUIIDIIG P #£l A BEc.J-60x ___ -- HE7FR ON 94't _ ._- - P ONES,AND TOPOGRAPHIC FEATURES AS SHOWN HEREON.A IM B-2A' TIC LEVEL W!5 USED TO CHECK AND ESTABLISH THE ELEVATION OF ; I I BENCHMARKS AND CONTROL POINTS.THE RESULTING DATA MEETS OR E:KaEDs THE O E STANDARDS FOR LAND BOUNDARY SURVEYS AS SET FORM IN WAD 332-130-090. _ (� ApD.^ Y4 i OF DiIt6�lam€ BLOC. _ x"� TEL is 0 _ SSISI r/VACATED i/M/9848 pyyN soulN VAUL -ff- '>s`}}y,, ''. 7 GATES OF SURVEYS ral-.7.M FIELD SURVEYS BY BARGLWSEN CONSULTING ENCINEF7tS.INC. „Wj ( £(j4 E 10'CNC IIM2 A f O.e't SOU1N FOUND NAL f° I CONDUCTED APRIL,ROOT aD 7 1 CC 5.4 ♦ / !WASHER ; f ALL MOfA1MEN15 Sf10VM AS FOUND WERE V15fTED AT THAT TIME 2 • HORIZONTAL DATUM-BASIS OF BEARINGS e W } } ♦ > r1 \ NORM AMERICAN DATUM OF 1 gdT 1O (( 0 983(91)- NAD 8o(BU s O c €1 / / f AS ADOPTED!DEVELOPED BY Cltt OF RENTON PUBLIC WORKS DEPARTMENT R Z e t} WASHINCIDN STATE PLANE By SYSTEM-NORM ZONE g Q fi d ell 1 pL THE 8EAF0NC OF THE LINE BETWEEN RENTON CONTROL Pt./205!PL/884 ' ¢ O / i k TNNGNN AS Noftlt SC00'S9 W.0 AS CALCULATED FROM THE GRD COORDINATES. 1 / F JA„` f4 4 I } ° OWANCES SHOWN HEREON ARE GROUND. _ , VERTICAL DATUM -BASIS Of ELEVATION$ O W € ]C NORTH AMERICAN VERTICAL DATUM OF INS-NAVD 88 V Z Z AS ADOPTED h DEVELOPED BY Cltt OF RENTON PUBLIC WORKS DEPARTMENT e Z PROJECT BEIICWARK N O T i. f FD.3•BRASS DISK STAMPED'KING COUNTY SURVEY MONUMENT EN-80 1973- p Z I I! '/+I I J ....- gyp✓ Z I SET IN RD(t J(NORM SIDE OF AIRPORT WAY.30'+WEST FROM RUNWAY MARKER. y O t UA F ELF HNRNR CORER Cfil'of RENION BM/212e ELEV. ao.as FEET s Z p E1Fr..41.e)FEET .Y I J J4 }y ` 817E BENCHMARK F It O RY .it rrL �Ji Dy� t CHISELED'X'CENTER BOLT TOP OF FIRE HYDRANT O F r 2-CNC N.4415 %( j Ci_vyl�� , E 10'TOES W47SU } NfLSE 2 FT.WEST OF BACK(OF SIDEWALK WEST SIDE RMNIER AVE N. Q O iz•CNc s-44.n I I , - = lLEV.•41.Bo FEET CALCULATED LAND AREA z50 �� CB M�L0 WD)< It '}}j� " I8.615 t SD.R.(w 1.116 t Acrse) i �: 2 E 12'ADS 5.341i,_ Sit NOTES IE tY.05 31� I S y / l I.UNDERGROUND UTILITIES AND FEATURES DEPICTED HEREON ARE BASED ON 7'fi---Ya b T FIELD OBSERVATION.MARKINGS,DEVELOPMENT PLANS,MID/OR AVAILABLE T A v t TIT In n 70 e A n ♦ ;Pt ♦ ♦ RECORD DOCUMENTS ONLY.THE TRUE LOCAT)W NATURE 5' 1 r r. L_v I Vv. rw r r / 7; ?i i OF BELOW GROUND FEATURES.DETECTED ORUNDETECTEDAND/OR i OIAD BE EVT:RIRED. 101 ell YAUL7 I 1E 10'CNC � ek PROJECT INFORMATION > m 1`IO'J f; ) SteNft 1 LEGAL DESCRIPTION d O 'I3UILDIIJGS ON SITE Q$ OF DATOF SURVEY Ce(TTPE q f/ _ BLOCK Bz OF N.H.unLEx•s LAKE wA91NcrON Pur.ACCORnNc ro THE PLAT THEREOF !s fi / lY CNC w� r FALL �I{,,'i RECORDED IN VOLUME 6 OF PLATS.PARE 70.IN KING COUNTY,WASHHGTOft Q N O ROCKERYs'S1.05 nIC E�1.� / F i\ IXEXTET610N ROAD,RECORDED UNDER RECORgNG N0.35CEPT PORTION THEREOF DEMM TO THE STATE OF ASH FOR RENTON AVEM/E C� O M TOGETHER WITH SOUTH KW OF VACATED SOUTH 131ST.STREET ADJOINING. CA Z W `I FOUND CB 2.0'2 NOWD4 NC NW�9.75 1 r' lr, � `� Ij I S` IrM=ca XSe') � w )} $ TAX LOT NUMBER 817E ADDRESS Q Q C !s 3 N ppESE�Z,Agy i 420M0-0355NC 251 RARER AVENUE W NO E_TI.e0 1 f y1' T I E tr CNC W-1146 Wes.5.42 t -IE iY ENC 9.J0. RFNTON.WA 98OW I r, E 8,CNC W-W 4e E 12•OI: Q. NC St.45 g ( 1 %:� � Eta'CNC I1N.31.25 d Z„� o E 1Y CNC E 33.e1 l E fY piC� 1 CURRENT OWNER i l CMC EOT W t ROOM A MNKLER AND PAMELA W.YNKL_ER,TRUSTEES OF THE Q (,) ROBERT A AND PAMELA(.ia)W.WNKLER TRUST,AND SUCCESSORS,AS AMENDED {£ I LAND USE GOVERNING JURISDICTION CITY OF RENTON ZONING COMMERCIAL ARTERIAL CA 1 /�Yr ri,.✓ "� FLOOD INFORMATION Y. MANAGFAIIENT)MAPAGENCY(FEMA)INFORLIATION: ^✓:, ' `I Wyr"JA(, sd`ZFIRM OF 1 TED MA IB 1995. .53b33C0977 F if l N Z I. DETE TO E 500- I Z NOTES T � a� 1.COMMONWEALTH LAND TITLE INSURWICE Cwwy COMMITMENT NO.H905513, I� c t „ - (DATED OCTOBfft 2,2001 AT 5:00 AM.)WAS RQ1ED UPON FOR TIRE INFORMATION AEllI SUPPORTING DOCUMENTATION.PIFASE REFER TO THAT REPORT FOR fURT ER �) g INFORMATION REGARDING FINANCIAL MATTERS BEYOND THE SCOPE OF THIS SURVEY. IY-46.18 I TInN FlPES 9 / �L �� N4T.79 �r OI s E 8'CNC E_36.30� ,'�.:- 5-13.79 �' E e'CHC E-3630 INS 6� f2 _ J-sox Py� 1 SCALE: 1'.20' � 1 f v"u F rD.ibfl 3.L3•�1vf�- � .._� �O / ALTA / AGSM LAND TITLE SURVEY For: ARCO PRODUCTS COMPANY PORTION /4 of the N.W. 1/4 of SECTION 18, P of the N E. 1 \ SSW , Township 23 Nolth, Range 5 East, Willamette Meridian 9,'s a )E 10 RfM-12.72 3 1►leant ``a+-uses ff o, p er' City of RENTON KING County State of WASHINGTON .v t,-fasl F 10'a+c N'3a,ao aD F 1O CNc E-3s es -ia�a' l/ SITE a c MI OD DM1.-ZTaYst� E io'CHC w-7Bss tE ra•CHC N a70 ,� a 1 ' Cq I I - #�•aw 14-3679 LEGEND 1 The undersigned hereby certifies to: 1 1E 1�CNC N-76.39 9 Y ,FO N N 1 / Lau+uLr B 9AV Ip,�Us NMI ATLANTIC RICHAELD COMPANY,A Delaware Corporation, and 14 N N �t1 p F0 1E7�) I K.f COMMONWEALTH LAND TITLE INSURMICE COMPANY of Bellevue Washington, 5.Y �n o POIFR POLE + BtmN am" Moral as of the date hereof, that this survey correctly depicts the conditions E nA�� ® 'MINI tglm) tOIIa IFIIW/rX W No p) of this site on the basis of a Field survey performed in April 2001. �p / ❑ awl Do(CB) 0 LOUD IGD/E1LI in accordance with current ' inimum Standard Detail Requirements P Oh S I / ® SWIM MVIIaE(SOW) for ALTA/ACSM Land Title Surveys'jointly established and adopted by ,TA r s 926 _ � 40 0 �.�=� '�T ALTA ACSM and NSPS in 1999. ` 6� f lEl@IDNE W4D - NOW MEN IMLIMA TIE 1 V WOG WOLF _O_O_ LIE _ Bi Mo KIER WIBIDE MY1oCWD ~ z SLW Par#IFeet9ono S W"MIL -r(MI- alWl Q*]NW TO" ,v.:. Date: 1 OON I6 �� i Y@IW OF WNpE WAILV/ Y iOp/I Sl OQ' m F. Professional Land SurveyorCO l T rmr®08- -02 s Washington Registration No.3D582 Ar• ' 2/11/02 12 : 6 : 56 am Sha reware Release page 1 ARCO-NWC OF RAINIER AVE AND RENTON AVE ' JOB NO. 7816 WORKS4 FILE NO. 7816 .BSN ----------------------------------- ' BASIN SUMMARY ' BASIN ID: 100DEV NAME: 100 YR DEVELOPED SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP ' PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0 . 38 Acres 0 . 89 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 ABSTRACTION COEFF: 0 . 20 TC. . . . : 7 . 96 min 7 . 96 min ' TcReach - Sheet L: 55 . 00 ns : 0 . 1500 p2yr: 2 . 00 s : 0 . 0360 TcReach - Shallow L: 120 . 00 ks :27 . 00 s : 0 . 0050 ' TcReach - Channel L: 150 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE: 0 . 92 cfs VOL: 0 . 35 Ac-ft TIME: 480 min BASIN ID: 10DEV NAME: 10 YR DEVELOPED ' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP ' PRECIPITATION. . . . : 2 . 90 inches AREA. . : 0 . 38 Acres 0 . 89 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 ABSTRACTION COEFF: 0 . 20 TC. . . . : 7 . 96 min 7 . 96 min ' TcReach - Sheet L: 55 . 00 ns : 0 . 1500 p2yr: 2 . 00 s : 0 . 0360 TcReach - Shallow L: 120 . 00 ks :27 . 00 s : 0 . 0050 TcReach - Channel L: 150 . 00 kc :42 . 00 s : 0 . 0050 ' PEAK RATE: 0 . 65 cfs VOL: 0 . 25 Ac-ft TIME: 480 min BASIN ID: 10PRE NAME: 10 YR PREDEVELOPED ' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 90 inches AREA. . : 1 . 27 Acres 0 . 00 Acres ' TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 85 . 00 0 . 00 ABSTRACTION COEFF: 0 .20 TC. . . . : 29 . 70 min 0 . 00 min ' TcReach - Sheet L: 250 . 00 ns : 0 .2400 p2yr: 2 . 00 s : 0 . 0360 PEAK RATE: 0 . 29 cfs VOL: 0 . 16 Ac-ft TIME : 490 min 2/11/02 12 : 6 : 56 am Shareware Release page 2 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO. 7816 .BSN BASIN SUMMARY ' BASIN ID: 2DEV NAME: 2 YR DEVELOPED SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs ' RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 00 inches AREA. . : 0 . 38 Acres 0 . 89 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 ' TC. . . . : 7 . 96 min 7 . 96 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 55 . 00 ns : 0 . 1500 p2yr: 2 . 00 s : 0 . 0360 TcReach - Shallow L: 120 . 00 ks : 27 . 00 s : 0 . 0050 TcReach - Channel L: 150 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE: 0 .42 cfs VOL: 0 . 16 Ac-ft TIME : 480 min ' BASIN ID: 2PRE NAME: 2 YR PREDEVELOPED SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 00 inches AREA. . : 1 . 27 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 85 . 00 0 . 00 TC. . . . . 29 . 70 min 0 . 00 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 250 . 00 ns : 0 . 2400 p2yr: 2 . 00 s : 0 . 0360 PEAK RATE: 0 . 14 cfs VOL: 0 . 08 Ac-ft TIME: 490 min ' BASIN ID: WQDEV NAME: 1/3 2 YR PRECIP. W.Q. DEV SBUH METHODOLOGY ' TOTAL AREA. . . . . . . : 1 . 27 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 0 . 67 inches AREA. . : 0 . 38 Acres 0 . 89 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 98 . 00 TC. . . . : 7 . 96 min 7 . 96 min ABSTRACTION COEFF. 0 . 20 TcReach - Sheet L: 55 . 00 ns : 0 . 1500 p2yr: 2 . 00 s : 0 . 0360 ' TcReach - Shallow L: 120 . 00 ks :27 . 00 s : 0 . 0050 TcReach - Channel L: 150 . 00 kc :42 . 00 s : 0 . 0050 PEAK RATE: 0 . 10 cfs VOL: 0 . 04 Ac-ft TIME: 480 min r ' 2/11/02 12 : 6 : 56 am Shareware Release page 3 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO, 7816 .BSN HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres ' 1 0 . 136 570 6904 cf 1 .27 2 0 . 294 520 10797 cf 1 . 27 ' 3 0 . 124 570 6904 cf 1 .27 4 0 . 253 550 10797 cf 1 . 27 5 0 . 363 550 15229 cf 1 .27 ' 2/11/02 12 : 6 : 56 am Shareware Release page 4 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO. 7816 .BSN STORAGE STRUCTURE STRUCTURE LIST ' RECTANGULAR VAULT ID No. 1 Description: INITIAL VAULT ' Length: 30 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 RECTANGULAR VAULT ID No. 2 ' Description: VAULT WITH 30 % EXTRA Length: 40 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 t 2/11/02 12 : 6 : 56 am Shareware Release page 5 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO. 7816 .BSN ------------------ STAGE STORAGE TABLE ' RECTANGULAR VAULT ID No. 1 Description: INITIAL VAULT Length: 30 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 ' STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 32.00 0.0000 0.0000 33.60 960.00 0.0220 35.20 1920 0.0441 36.80 2880 0.0661 32.10 60.000 0.0014 33.70 1020 0.0234 35.30 1980 0.0455 36.90 2940 0.0675 32.20 120.00 0.0028 33.80 1080 0.0248 35.40 2040 0.0468 37.00 3000 0.0689 32.30 180.01 0.0041 33.90 1140 0.0262 35.50 2100 0.0482 37.10 3060 0.0702 ' 32.40 240.00 0.0055 34.00 1200 0.0275 35.60 2160 0.0496 37.20 3120 0.0716 32.50 300.00 0.0069 34.10 1260 0.0289 35.70 2220 0.0510 37.30 3180 0.0730 32.60 360.00 0.0083 34.20 1320 0.0303 35.80 2280 0.0523 37.40 3240 0.0744 32.70 420.00 0.0096 34.30 1380 0.0317 35.90 2340 0.0537 37.50 3300 0.0758 32.80 480.00 0.0110 34.40 1440 0.0331 36.00 2400 0.0551 37.60 3360 0.0771 32.90 540.00 0.0124 34.50 1500 0.0344 36.10 2460 0.0565 37.70 3420 0.0785 33.00 600.00 0.0138 34.60 1560 0.0358 36.20 2520 0.0579 37.80 3480 0.0799 33.10 660.00 0.0152 34.70 1620 0.0372 36.30 2580 0.0592 37.90 3540 0.0813 33.20 720.00 0.0165 34.80 1680 0.0386 36.40 2640 0.0606 38.00 3600 0.0826 33.30 780.00 0.0179 34.90 1740 0.0399 36.50 2700 0.0620 38.00 3600 0.0826 33.40 840.00 0.0193 35.00 1800 0.0413 36.60 2760 0.0634 33.50 900.00 0.0207 35.10 1860 0.0427 36.70 2820 0.0647 ' 2/11/02 12 : 6 : 56 am Shareware Release page 6 ARCO-NWC OF RAINIER AVE AND RENTON AVE JOB NO. 7816 WORKS4 FILE NO. 7816 .BSN STAGE STORAGE STORAGE TABLE RECTANGULAR VAULT ID No. 2 Description: VAULT WITH 30 % EXTRA Length: 40 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---Cf--- --AC-Ft- (ft) ---cf--- --AC-Ft- (ft) ---Cf--- --AC-Ft- (ft) ---Cf--- --AC-Ft- --------------------- 1 32.00 0.0000 0.0000 33.60 1280 0.0294 35.20 2560 0.0588 36.80 3840 0.0882 32.10 80.000 0.0018 33.70 1360 0.0312 35.30 2640 0.0606 36.90 3920 0.0900 32.20 160.00 0.0037 33.80 1440 0.0331 35.40 2720 0.0624 37.00 4000 0.0918 32.30 240.00 0.0055 33.90 1520 0.0349 35.50 2800 0.0643 37.10 4080 0.0937 32.40 320.00 0.0073 34.00 1600 0.0367 35.60 2880 0.0661 37.20 4160 0.0955 32.50 400.00 0.0092 34.10 1680 0.0386 35.70 2960 0.0680 37.30 4240 0.0973 32.60 480.00 0.0110 34.20 1760 0.0404 35.80 3040 0.0698 37.40 4320 0.0992 ' 32.70 560.00 0.0129 34.30 1840 0.0422 35.90 3120 0.0716 37.50 4400 0.1010 32.80 640.00 0.0147 34.40 1920 0.0441 36.00 3200 0.0735 37.60 4480 0.1028 32.90 720.00 0.0165 34.50 2000 0.0459 36.10 3280 0.0753 37.70 4560 0.1047 33.00 800.00 0.0184 34.60 2080 0.0478 36.20 3360 0.0771 37.80 4640 0.1065 33.10 880.00 0.0202 34.70 2160 0.0496 36.30 3440 0.0790 37.90 4720 0.1084 33.20 960.00 0.0220 34.80 2240 0.0514 36.40 3520 0.0808 38.00 4800 0.1102 33.30 1040 0.0239 34.90 2320 0.0533 36.50 3600 0.0826 38.00 4800 0.1102 33.40 1120 0.0257 35.00 2400 0.0551 36.60 3680 0.0845 33.50 1200 0.0275 35.10 2480 0.0569 36.70 3760 0.0863 1 t i 1 1 2/11/02 12 : 6 : 56 am Shareware Release page 7 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO. 7816 .BSN - -- ---------- DISCHARGE STRUCTURE LIST ' MULTIPLE ORIFICE ID No. 1 Description: ORIFICE DESIGN Outlet Elev: 32 . 00 ' Elev: 30 . 00 ft Orifice Diameter: 1 . 8223 in. Elev: 34 .40 ft Orifice 2 Diameter: 2 . 1680 in. 2/11/02 12 : 6 : 56 am Shareware Release page 8 JOB NO. 7816 ARCO-NWC OF RAINIER AVE AND RENTON AVE WORKS4 FILE NO. 7816 .BSN STAGE DISCHARGE TABLE ' MULTIPLE ORIFICE ID No. 1 Description: ORIFICE DESIGN Outlet Elev: 32 . 00 Elev: 30 . 00 ft Orifice Diameter: 1 . 8223 in. Elev: 34 .40 ft Orifice 2 Diameter: 2 . 1680 in. i 11. If ' STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---cfs-- ------- (ft) ---cfs-- (ft) ---cfs-- ------- (ft) cfs-- ------ 32.00 0.0000 33.60 0.1140 35.20 0.2753 36.80 0.3950 32.10 0.0285 33.70 0.1175 35.30 0.2847 36.90 0.4011 32.20 0.0403 33.80 0.1209 35.40 0.2937 37.00 0.4072 ' 32.30 0.0494 33.90 0.1242 35.50 0.3024 37.10 0.4131 32.40 0.0570 34.00 0.1274 35.60 0.3107 37.20 0.4189 32.50 0.0637 34.10 0.1306 35.70 0.3188 37.30 0.4247 ' 32.60 0.0698 34.20 0.1337 35.80 0.3266 37.40 0.4303 32.70 0.0754 34.30 0.1367 35.90 0.3342 37.50 0.4359 32.80 0.0806 34.40 0.1396 36.00 0.3416 37.60 0.4414 32.90 0.0855 34.50 0.1828 36.10 0.3488 37.70 0.4468 33.00 0.0901 34.60 0.2023 36.20 0.3558 37.80 0.4522 33.10 0.0945 34.70 0.2179 36.30 0.3627 37.90 0.4575 33.20 0.0987 34.80 0.2315 36.40 0.3694 38.00 0.4627 33.30 0.1027 34.90 0.2436 36.50 0.3760 33.40 0.1066 35.00 0.2549 36.60 0.3825 33.50 0.1104 35.10 0.2654 36.70 0.3888 1 ' 2/11/02 12 : 6 :58 am Shareware Release page 9 ARCO-NWC OF RAINIER AVE AND RENTON AVE JOB NO. 7816 WORKS4 FILE NO. 7816 .2SN LEVEL POOL TABLE SUMMARY ' MATCH INFLOW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id (cfs) VOL (cf) 2 YR EVENT ................... 0.14 0.42 1 1 34.27 1 0.14 1364.35 cf 10 YR EVENT ....... ........... 0.29 0.65 1 1 35.41 2 0.29 2045.20 cf 2 YR FINAL ROUTED 0.00 0.42 2 1 33.88 3 0.12 1507,82 cf ' 10 YR FINAL ROUTED .......... . 0.00 0.65 2 1 34.99 4 0.25 2389.25 cf 100 YR FINAL ROUTED .......... 0.00 0.92 2 1 36.30 5 0.36 3439.41 cf APPENDIX "C" LEVEL 1 DOWNSTREAM ANALYSIS 1 1 ' LEVEL 1 DRAINAGE ANALYSIS Proposed ARCO AM/PM Facility NWC - Renton Avenue Extension and Rainier Avenue North Renton, Washington 1 1 Prepared for: Atlantic Richfield Company ' 4 Centerpointe Drive La Palma, California ' 90623-1066 1 June 22, 2001 ' Our Job No. 7816 1 (BHA(dam CIVIL ENGINEERING, LAND PLANNING,SURVEYING, ENVIRONMENTAL SERVICES 18215 72ND AVENUE SOUTH, KENT,WA 98032 . (425)251-6222 • (425)251-8782 FAX www.barghausen.com TABLE OF CONTENTS ' 1.0 PROJECT OVERVIEW 2.0 UPSTREAM DRAINAGE ANALYSIS 3.0 DOWNSTREAM DRAINAGE ANALYSIS AND PROBLEM SCREENING 4.0 RESOURCE REVIEW ' 4.1 Basin Reconnaissance Summary Report 4.2 Floodplain and Floodway FEMA Maps 4.3 Other Off-Site Analysis Reports ' 5.0 SENSITIVE AREAS FOLIOS ' 6.0 CONCLUSION ' EXHIBITS EXHIBIT"A" VICINITY MAP ' EXHIBIT`B" DOWNSTREAM DRAINAGE MAP ' EXHIBIT"C" OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE EXHIBIT"D" FEMA MAP ' EXHIBIT"B" UPSTREAM BASIN MAP EXHIBIT"F" SCS SOILS MAP EXHIBIT"G" ASSESSOR'S MAP ' EXHIBIT"H" BASIN RECONNAISSANCE SUMMARY REPORT ' EXHIBIT"I" SOILS REPORT EXHIBIT"J" SENSITIVE AREAS FOLIOS 1 1.0 PROJECT OVERVIEW 1 1 1 1.0 PROJECT OVERVIEW The proposed ARCO AM/PM project is to develop approximately 1.116 acres into a gasoline station, with appropriate drive aisles, fueling areas, gasoline storage tanks,water quality/detention,catch basin ' collection and conveyance system,and paving. The project is located within a portion of the Northeast quarter of the Northwest quarter of Section 18,Township 23 North,Range 5 East,Willamette Meridian, City of Renton, King County, State of Washington. For a more localized description,the project site is ' located at the northwest corner of Renton Avenue South and Rainier Avenue North. The enclosed Vicinity Map, Exhibit "A," depicts the approximate location of the proposed site. The existing topography of the site has slopes ranging from 3 to 4 percent and is fairly constant across the site,sloping from the northwest to the southeast portion of the site. The site had previous development located on it; ' however,all evidence of it is removed at this time. The facility is currently served by six driveways along the frontages of Renton Avenue South and Rainier Avenue North. There is no curb and gutter along the western property line of the site,which is bordered by Hardie Avenue N.W. A small half-acre upstream ' basin contributes runoff to the site,which sheetflows across the western property line from the northwest. This basin will not be contributing to the site once it is developed, as curb,gutter, and sidewalk will be installed along the frontage of Hardie Avenue N.W. All upstream runoff will be routed to the collection ' and conveyance system in Hardie Avenue N.W., which ultimately discharges to the same culvert in Renton Avenue South that the site does. ' 7816.011 [JPJ/ath/rh] 1 2.0 UPSTREAM DRAINAGE ANALYSIS 1 1 1 1 1 2.0 UPSTREAM DRAINAGE ANALYSIS Based on topographic maps(1 inch equals 200 feet)provided by the City of Renton and from our site visit,it appears that there is a small portion of upstream flow onto and through the site. This flow is very ' minimal in size and consists of one half of an acre which sheetflows ultimately in the gutter flow line of the property to the north within the right-of-way of Hardie Avenue N.W., and sheetflows onto our site because no curb and gutter is installed in Hardie Avenue N.W. along our property frontage. Once this curb, gutter, and sidewalk are installed at this development, this upstream flow will not enter the site. ' It will ultimately course down Hardie Avenue N.W. and discharge into the same 48-inch culvert in Renton Avenue South that the site drains into. Please refer to the Upstream Basin Map for further description of the upstream basin. 1 1 i i i 1 1 1 1 1 1 7816.011 [JPJ/ath/rh] t 3.0 DOWNSTREAM DRAINAGE ANALYSIS AND PROBLEM SCREENING 1 1 1 1 1 1 i 1 3.0 DOWNSTREAM DRAINAGE ANALYSIS AND PROBLEM SCREENING The Off-Site Analysis Drainage System Table lists the downstream conveyance from the site (Exhibit "C"). The Off-Site Analysis Drainage System Table is shown pictorially on Exhibit `B." Apparently the site is part of a much larger drainage basin contributing to Lake Washington via the large diameter culvert and reinforced box culverts which flow in a northerly direction along the western frontage of the Renton Municipal Airport, from the southwest corner of the airport all the way to the north,discharging into Lake Washington. Please refer to the Off-Site Analysis Drainage System Table for a complete description of the downstream drainage course. 7816.011 [JPJ/ath/rh] w W U w O d' ■■�r � � � r � � � � � � � r � � � s � � 4.0 RESOURCE REVIEW The following is a description of each resource reviewed in preparation of this Level 1 Drainage Analysis: ' 4.1 Basin Reconnaissance Summary Report The site is located within the lower Cedar River Basin. However,runoff from the site does not ' enter the Cedar River. Instead it is conveyed directly into Lake Washington. 4.2 Floodplain and Floodway FEMA Maps Please see the enclosed FEMA Map utilized for this analysis,Panel No.977 of 1725,and Map No. 53033CO977 F, revised May 16, 1995. As indicated by this map, the proposed project site does not lie within a floodway or a floodplain. Refer to Exhibit"D." 4.3 Other Off-Site Analysis Reports A US Department of Agriculture Soil Conservation Service map is provided. The soils of this site were mapped as BeC, Beausite, 6 to 15 percent slopes. A soils report is also included, see Exhibit"I." 7816.011 [JPJ/ath/rh] 5.0 SENSITIVE AREAS FOLIOS 1 1 1 5.0 SENSITIVE AREAS FOLIOS Based on review of the King County Sensitive Area Folios, it was found that the site discharges to the downstream drainage course of an unclassified stream. The site itself,however, is not located within a Sensitive Area. 7816.011 (JPJ/ath/rhl �/1 U O `C r 6.0 CONCLUSION We are not aware of flooding, siltation, or erosion problems in the downstream drainage course. Therefore,by providing the detention and water quality facilities in accordance with the City of Renton requirements, this project is developable as proposed. r r r r r r r 1 r7816.011 [JPJ/ath/rh] N w M EXHIBIT "A" VICINITY MAP 1 AV L(3 rl d' t �°"..,r a .. 1V �•3" N 4 W � � r�^N1,Av+ I MJAWI I I _ } rc HISET 3N AYyWJ $ 'kxU N 3g yr. I Y,:,, ! .-. 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M � 1500 � �E N N N �� V ALLEY o cs AY M ^C w Q G y K+ i A to G b Ail vn 0 p N �6, c eo F- MN 0, AY ON NS nv an hr Ar r 3l �.. J W to AY SN9A315 Ni r 001 s3/l K1 Nv3i OO6I ` b ~ ©NI1 Ay Av YJ3N3S MS AY Vo N S 398 001 `� MS AV FF ON Ytl � �_ _ ' () Ay $h _MS—A_Sr1A]Nl 6 P/ - ONONAYtl ONZBOOL d 'is A4 T13NOd - r. 1 1 1 1 1 1 EXHIBIT "B" DOWNSTREAM DRAINAGE MAP 1 1, PIRM vuXIIy� v�, 1 B,t\- \\�\ jl'n�jj 1�� 1�1 �Ti?,rfartllAli�gti - - >rn r ,-tee•�, �/�11 �Z;�� ��y a�,1 CM )/ PS laws 711 JU MIR r 1 1 • _� M, y �.Sil IP 1 41ri�i a r'% � ir, ilr1I All 1 /l AID F 1 b�1r��A/ • rv1 .,i I eau *�°o���'aNii�:H���'!� �z' I,�11f)t-`�� 16 f • r \7� y1�4�'��' \�!I \��r� ap��r1t✓/�ICI !111�m-. np{. - ;,,1 �) s,, �� � �`)I ' :l I' u ',rr'1Ir1�1 q�4()hl��ji�►1� ��i I 1A - i ck t•w1�'ir' I�l 11 i,A��rs3ltr sfRNQ•�� IV `�tr 66 u /, ■II rl A'"�i d��AA�( 9r 11�l NI I iG.hll� �i 11 MI q ,NIA {�ir'NJ�r'•,r I�,�\J��1 � ��'� �� r, l� �i R I,n�mnn»1��h I iul ''Iprop, - to>'��—a . �I t 4 � � ' firs l'� •�'��`� ♦ r !„� 4~so► �.df�/r �I,�I. In �ox7ti�itlr] !'Ili'JM �A�)•J� n g MIS 1�) m rN! 3• RI NOW r m•,�IM� �y//��� ��� �►.� 14 MY '..■��``� ' • � {:Y� t 4r� 4ab Max fill \\\\`1. �`��\■`V�/•- .•y v 11•JPool II ? ��ll I 'i ;✓'Srf ,,{h ���� • ��l 6�=+•` 11 I'• � �:, �r� :�..1} ��. � _� �- ��' p ICI.. � 'CIyK�. .• �l4 ���'"�� �� ��� ,��: n,r r`Mi Il �ll %/.•SJ� 1� IXPI • �ai(j `�"' .�/�r�•����r-' r\ \ 'I��i��3�, IIJA����IIr11�� IanY✓I� �i��Jr��' r',1!I NIQ C.r� 1b,� �� ,���� �;�r,r�)J ,•i '`�I� //e� r��1111� c w -`� .-,�.v..:ate�.:f,sri ✓ 'L"":- i I li - r � , ' EXHIBIT "C" OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE 1 1 OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE ARCO AMIPM Facility Located at NWC - Renton Avenue and Rainier Avenue North Basin:Lake WashinetonSubbasin Name:Subbasin Number: Symbol Drainage Component Drainage Component Slope Distance Existing Potential Observations of Field Type,Name, and Size Description from Site Problems Problems Inspector Discharge Resource Reviewer,or Resident See Map Type:sheet flow,Swale,stream, Drainage basin,vegetation,cover, I Ft Constrictions,under capacity,ponding, Tributary area,likelihood of problem, channel,pipe,pond;size,diameter, depth,type of sensitive area,volume overtopping,flooding,habitat or overflow pathways,potential impacts surface area organism destruction,scouring,bank sloughing,sedimentation,incision, other erosion 1 12" RCP From site to SDMH in Renton 9.5�i 0' to 20' None noted None noted Drains entire site Avenue 2 48" RCP Flows to east under Rainier 1.7% 20'to 255' None noted None noted Flows to MH at airport Avenue North 3 60"RCP Pipe curves to north 0.23% 255'to 489' None noted None noted Under west road at airport 4 60"RCP Flows north 0.23% 489'to 2,127' None noted None noted Under west road at airport 5 Tx 5'RCB Culvert flows north 0.1% 2,127'to 4,310' None noted None noted Under west road at airport 7816.011 1JPJ/ath] a Q H ww LEGEND SPECIAL FLOOD HAZARD AREAS INUNDATED BY 100—YEAR FLOOD ZONE A No base flood elevation,determined. ® NATIONAL FLOOD) INSURANCE PROGRAM ZONE AE Base flood elevations determined. ZONE AM Flood depths of 1 to 3 feet (usually areas of prmdinpl; base flood elevations determined. ' ZONE AO Flood depth,of 1 to 3 feet (usually sheet Row rm sloping terrain); average depths FIRM determined.For areas of alluvial fan flooding velocitiex also determined. FLOOD INSURANCE RATE MAP ZONE A99 To be protected d from 100 year flood by ' Federal flood protection elevations system under ca,huction;no base elevation,determined. ZONE v Coastal flood with velocity hazard (wave KING COUNTY, action);no base Rood elevatior,determined. WASHINGTON AND ZONE W Coastal Rood with velocity hazard (wave action); base flood elevations determined. INCORPORATED AREAS FLOODWAY AREAS IN ZONE AE OTHER FLOOD AREAS PANEL 911 OF 1125 ZONE X Areas of 500-year Rood;areas of 100.year Rood with average depth, of less than (SEE MAP INDEX FOR PANELS NOT PRINTED) 1 foot or with drainage are. less than 1 square mile; and are. protected by levees from 100-year flood. OTHER AREAS CONTAINS: ZONE X Arm determined to be outside 500-year COMMUNITY NUMBER PANEL SUFFIX floodplam. ZONE D Are. in which flood hazards are KING COUNTY, undetermined. UNINCORPORATED AREAS 530071 ego F REMON.CRY OF 5300e8 og» F UNDEVELOPED COASTAL BARRIERS Identified Identified Otherwise 1983 1990 Protected Arco ' Coss tat bamer areas we nomully, located within or adjacent to Special Flood Hazard Areas. Flood Boundary Floodway Boundary MAP NUMBER _ _ Zone D Boundary 53033CO971 F Boundary Dividing Special Flood Hazard Zones, and Boundary MAP REVISED, Dividing Areas of Different ydN Coastal Base Flood Elevations MAY 16,1995 Z Special Flood Hazard Base Flood Elevation Line; ' 513 Elevation in Feet. See Map Index for Elevation Datum. Cross Section Line ' (EL 987E Base Flood Elevation in Feet Federal Emergency Management A enc Where Unlorm within Zone. g y RM7 See Map Index for Etevation Datum. X Elevation Reference Mark 0 M2 River Mile ' Horizontal Coordinates;Based on North 97007'30",32022'30" American Datum of 1927(NAD 27) Projection. ' coTAuS S y FEMA MAP NORTH ' Mar♦ ..... ......... .�N....w..•• ...: :... i........ ...... ua.• Er.a s ........ 1 ra.. • .... •i• ....E.....n �4 ii s ZONE Z 7 !! r•r.. ... ..�........ U ZLl GiiY OF RENTON 53008E r LONE k � •x.lr f anH. p[O 5 F i 1 n 18 sxff ` LONE k L ' LONE k pm .x�a zoNe q� ra«E x ZONE i i LONE Z- ' .� .+ CITY OF RENTON 53 5300E8 LONE k n� aER� AML6 20 ws r.NN rc wcEno .EEIEIEE TOwNiaEE 1]EEOBIH,BNVOE 5 L.A. - FEMA MAP 1 NuJO,o� NORTH EXHIBIT "E" UPSTREAM BASIN MAP 1 1 1 1 1 1 1 1 1 � '— `���_--� ■ irk �— ■ � ■ ■ ■ m ------f 27 \\ rn S•— i 25o f co 2 _ _S 88 th.=--AVEit . �- -2p —�- -- - --- -1 - E 1,657 I � t 06 x �} i125 r — It D ' f _ - -_ _ loo i 1 �• I — � II I - - - ___ ---- ------ -- C 1,658 a- -— x -- mz ALW i I I + _ I I I � I � � I I � 1 i X ► � L.��-- -- — 1I p L-- Irn cp doom dw I ►� II; 1 � ► I I -� X X N — 1I -- II � t _ _� I 1 I, i i I I �— • W I I 1 ..y�� /... ' EXHIBIT "F" SCS SOIL5 MAP 1 1 1 1 i 1 1 1 i RE 1 405, R.4 E. R.5 E. SEATTLE(CITY P.O.)IO MI.12'30" 6 M, TO INTERSTATE 90 �/��` (Joins sheet 5) A,c ISSAQU, SuOstat n7. Ur ae ~ `K� •� ,, i 'Ml AgD • 1 AgC• •.fit ,�a� a NI �; r o• •�--�'•'�� -� A 3 I y gC :BM .......::.«.:I a••. 64 Athletic ubsta' '• 1� `field I In t . I�' BM Ll11 0 I • EvD I r Ur •AkF I I 1 BeC 0eG ` • r �� • BeD ,� I 'aim-t L, ` I EvC I I . ' Cemi asebatt I yGRAVEL ' PIT . •• � .y Park PC ' • 6> I'. BM Ml an I ��� Rh• BeD BeC `f•..` ,• P kFaf i•��r ➢ i A EvC RA ROAD TU L' a F• d r y.• -��..' +��� ....... �e f ,Rq0 f ti •L \/7 L h ' UrUr1 P �� �ti I - I m • AkFInC I Y wo I I �I - ------ -- - 13 --- — I `•, -I •� i. • 5F Age BM137 Ak PY f i • 1 I -t sta I - AmC .- \\� � Golf urse �'1•-- - \ AgC PA IFS • t • I' -'Q - InC Sew ge ppTNE , . •' �' \ --- yo's�6� < \\\\, 'F IF Disp sal ACi o.:d r`Q l •n`. -�- 1�-•,• __'1- - Substa rn I ,11 `` Ak 20 •ti �J��. M 16 i .i 455 o i : i ' \\':�• Ur PU •' �79' 4 11 i !Longacrey;pi�' I Pu - .•� \ 515 '/) AavE / i Rom'i PY ui' ,,BeC I 1 a Wo BeD L/ ° 1:P Ur ��� I 'ii' 1 AgD 1, Wracks B 1 29 "' 31 w AgC r/ Ng ❑ R S rvOir t O 2 W as Pu ( m Sk W o I� \� u 2 MCfl u I '! L "nic 25 0 = pIBM 29 . Ag6 169 i203 AgC 2 n py I 1 ° 451 S k I •1. . i� �' --- I 0 IAgC d Some areas are up to 30 percent included soils to dark yellowish-brown gravelly sandy loam that that are similar to this soil material, but either extends to a depth of about 19 inches. The lower shallower or deeper over the compact substratum; part of the subsoil is olive-brown very gravelly and some areas are 5 to 10 percent very gravelly sandy loam. Fractured sandstone is at a depth of Everett soils and sandy Indianola soils. about 38 inches. Runoff is medium, and the erosion hazard is Beausite soils are used for timber and pasture. moderate to severe. Some areas have been used for urban development. This soil is used for urban development. Ca- pability unit IVe-2; woodland group 3d2. Beausite gravelly sandy loam, 6 to 15 percent Arents, Everett material ) .--'This is a level An slopes (BeC) .--Areas of this soil are 20 acres or ( - to gently sloping, dark-brown gravelly or very more in size. Slopes are long and convex. gravelly sandy loam. It is very similar to Everett Representative profile of Beausite gravelly gravelly sandy loam (see Everett series) , but it sandy loam, 6 to 15 percent slopes, in woodland, has been disturbed and altered through urban de- 570 feet south and 800 feet east of the northwest velopment. Multicolored very gravelly coarse sand corner of sec. 29, T. 24 N., R. 6 E.: is at a depth of 8 to 40 inches. Areas are common- ly rectangular in shape, and range from 1 to 120 01--2 inches to 1/2 inch, undecomposed leaf litter. acres in size. 02--1/2 inch to 0, black (IOYR 2/1) decomposed Representative profile of Arents, Everett mate- leaf litter. rial, in a homesite, 440 feet west and 100 feet Al--0 to 6 inches, dark-brown (IOYR 3/3) gravelly north of the center of sec. 11, T. 24 N., R. 6 E.: sandy loam, brown (10YR 5/3) dry; weak, fine, • granular structure; soft, very friable, 0 to 8 inches, dark-brown (7.5YR 3/4) gravelly nonsticky, nonplastic; many roots; slightly sandy loam, brown (7.5YR 5/4) dry; massive; acid; clear, wavy boundary. S to 7 inches soft, very friable, nonsticky, nonplastic; thick. few roots; 30 percent gravel content; B21--6 to 19 inches, dark yellowish-brown (10YR 4/4) slightly acid; clear, smooth boundary. 8 to gravelly sandy loam, light yellowish brown 14 inches thick. (IOYR 5/4) dry; massive; soft, very friable, 8 to 60 inches, grayish-brown and light olive-brown nonsticky, nonplastic; many roots; slightly (2.5Y S/2 an& 5/4) very gravelly coarse acid; clear, irregular boundary. 10 to 15 sand, light gray and light yellowish brown inches thick. (2.5Y 7/2 and 6/4) dry; single grain; loose, B22--19 to 38 inches, olive-brown (2.5Y 4/4) very nonsticky, nonplastic; few roots; 55 percent gravelly sandy loam, light yellowish brown gravel and 10 percent cobblestone content; (2.5Y 6/4) dry; massive; soft, very friable, medium acid. nonsticky, nonplastic; common roots; medium acid; abrupt, irregular boundary. The upper part of the soil ranges from dark IIR--38 inches, fractured sandstone; medium acid. brown to olive brown and from gravelly sandy loam to very gravelly loamy sand. The substratum ranges very dark The A horizon ranges from from black to olive brown. g Y grayish This soil is somewhat excessively drained. The brown to very dark brown and dark brown. The B effective rooting depth is 60 inches or more. horizon ranges from dark grayish brown to dark Permeability is rapid, and available water capacity Yellowish brown and olive brown. It is gravelly is low. Runoff is slow, and the erosion hazard and very gravelly sandy loam and gravelly loam. is slight. Depth to sandstone ranges from 20 to 40 inches. This soil is used for urban development. Ca- Some areas are up to 20 percent included Alder- pability unit IVs-l; woodland group 3f3. wood soils, which have a consolidated substratum, and Ovall soils, which are underlain by andesite; some are up to 5 percent the wet Norma and Seattle Beausite Series soils; some are up to S percent Beausite soils that ' have a gravelly loam surface layer and subsoil; and The Beausite series is made up of well-drained some are up to 10 percent soils that are similar to soils that are underlain by sandstone at a depth Beausite soils, but are more than 40 inches deep of 20 to 40 inches. These soils .formed in glacial over sandstone. deposits. They are rolling to very steep. Slopes Roots penetrate easily to bedrock and enter a are 6 to 75 percent. The vegetation is alder, fir, few cracks in the bedrock. Permeability is cedar, and associated brush and shrubs. The annual moderately rapid. Available water capacity is low. precipitation is 40 to 60 inches, and the mean Runoff is medium, and the hazard of erosion is annual temperature is about 50° F. The frost-free moderate. season is used for timber and pasture and for . 600 to 2,000 feet. P Capability season ranges from 160 to 190 days. Elevation is urban development. Ca abilit unit IVe-2; woodland In a representative profile, the surface layer group 3d2. ' and the upper part of the subsoil are dark-brown 11 GUIDE TO MAPPING UNITS ' For a full description of a mapping unit, read both the description of the mapping unit and that of the soil series to which the mapping unit belongs. See table 6, page 70, for descriptions of woodland groups. Other information is given in tables as follows: Acreage and extent, table 1, page 9. Town and country planning, table 4, page 57. Engineering uses of the soils, tables 2 and 3, Recreational uses, table 5, page 64. pages 36 through 55. Estimated yields, table 7, page 79. ' Woodland Described Capability unit group Map on symbol Mapping unit page Symbol Page Symbol AgB Alderwood gravelly sandy loam, 0 to 6 percent slopes---------- 10 IVe-2 76 3d2 AgC Alderwood gravelly sandy loam, 6 to 15 percent slopes--------- 8 IVe-2 76 3dl AgD Alderwood gravelly sandy loam, 15 to 30 percent slopes-------- 10 VIe-2 78 3dl AkF Alderwood and Kitsap soils, very steep------------------------ 10 VIIe-1 78 2d1 ' AmB Arents, Alderwood material, 0 to 6 percent slopes 1/---------- 10 IVe-2 76 3d2 AmC Arents, Alderwood material, 6 to 15 percent slopes 1/--------- 10 IVe-2 76 3d2 An Arents, Everett material 1/------------------------------------ 11 IVs-1 77 3f3 BeC Beausite gravelly sandy loam, 6 to 15 percent slopes---------- 11 IVe-2 76 3d2 BeD Beausite gravelly sandy loam, 15 to 30 percent slopes--------- 12 VIe-2 78 3dl BeF Beausite gravelly sandy loam, 40 to 75 percent slopes--------- 12 VIIe-1 78 3dl Bh Bellingham silt loam------------------------------------------ 12 IIIw-2 76 3w2 Br Briscot silt loam--------------------------------------------- 13 IIw-2 75 3wl ' Bu Buckley silt loam--------------------------------------------- 13 IIIw-2 76 4wl Cb Coastal beaches----------------------------------------------- 14 VIIIw-1 78 --- Ea Earlmont silt loam-------------------------------------------- 14 IIw-2 75 3w2 Ed Edgewick fine sandy loam-------------------------------------- 15 IIIw-1 75 2ol EvB Everett gravelly sandy loam, 0 to 5 percent slopes------------ 15 IVs-1 77 3f3 EvC Everett gravelly sandy loam, 5 to 15 percent slopes----------- 16 VIs-1 78 3f3 EvD Everett gravelly sandy loam, 15 to 30 percent slopes---------- 16 Vle-1 77 3f2 EwC 'Everett-Alderwood gravelly sandy loamy, 6 to 15 percent slopes------------------------------------------------------ 16 VIs-1 78 3f3 InA Indianola loamy fine sand, 0 to 4 percent slopes-------------- 17 IVs-2 77 4s3 InC Indianola loamy fine sand, 4 to 15 percent slopes------------- 16 IVs-2 77 4s3 InD Indianola loamy fine sand, 15 to 30 percent slopes------------ 17 VIe-1 76 4s2 KpB Kitsap silt loam, 2 to 8 percent slopes----------------------- 17 IIIe-1 75 2d2 KpC Kitsap silt loam, 8 to 15 percent slopes------------------ 18 IVe-1 76 �d2 KpD Kitsap silt loam, 15 to 30 percent slopes------------------ 18 VIe-2 78 2d1 KsC Klaus gravelly loamy sand, 6 to 15 percent slopes------------- 18 VIs-1 78 3f1 Ma Mixed alluvial land------------------------------------------- 18 VIw-2 78 2ol NeC Neilton very gravelly loamy sand, 2 to 15 percent slopes------ 19 VIs-1 78 3f3 Ng Newberg silt loam--------------------------------------------- 19 IIw-1 74 2ol A Nooksack silt loam-------------------------------------------- 20 IIw-1 74 2ol No Norma sandy loam---------------------------------------------- 20 IIIw-3 76 3w2 Or Orcas peat---------------------------------------------------- 21 VIIIw-1 78 --- Os Oridia silt loam---------------------------------------------- 21 IIw-2 75 awl OvC Ovall gravelly loam, 0 to 15 percent slopes------------------- 22 IVe-2 76 3d1 OvD Ovall gravelly loam, 1S to 25 percent slopes------------------ 23 VIe-2 78 3dl OvF Ovall gravelly loam, 40 to 75 percent slopes------------------ 23 VIIe-1 78 3dl ' Pc Pilchuck loamy fine sand-------------------------------------- 23 VIw-1 78 2sl Pk Pilchuck fine sandy loam-------------------------------------- 23 IVw-1 76 2sl Pu Puget silty clay loam------------------------------------ ----- 24 IIIw-2 76 3w2 Py Puyallup fine sandy loam-------------------------------------- 24 IIw-1 74 2ol ' RaC Ragnar fine sandy loam, 6 to 15 percent slopes---------------- 25 IVe-3 77 4sl RaD Ragnar fine sandy loam, 1S to 2S percent slopes--------------- 26 VIe-2 78 4sl RdC Ragnar-Indianola association, sloping: 1 -------- -- Ragnar soil--------------------------------------------- -- IVe-3 77 4sl Indianola soil------------------------------------------- -- IVs-2 77 4s3 RdE Ragnar-Indianola association, moderately steep: 1/------------ 26 -------- -- Ragnar soil--------------------------------------------- -- VIe-2 78 4sl Indianola soil------------------------------------------- __ VIe-1 77 4s2 U. S. GOVERNMENT PRINTING OFFICE:1973 0-468-266 GUIDE TO MAPPING UNITS--Continued Woodland Described Capability unit group Map on symbol Mapping unit page Symbol Page Symbol Re Renton silt loam-------------------------------------------- 26 IIIw-1 75 3w1 Rh Riverwash--------------------------------------------------- 27 VIIIw-1 78 --- Sa Salal silt loam--------------------------------------------- 27 IIw-1 74 2ol Sh Sammamish silt loam----------------------------------------- 27 IIw-2 75 3wl Sk Seattle muck------------------------------------------------ 28 IIw-3 75 --- Sm Shalcar muck------------------------------------------------ 29 IIw-3 75 --- Sn Si silt loam------------------------------------------------ 29 IIw-1 74 2ol So Snohomish silt loam----------------------------------------- 30 IIw-2 75 3w2 Sr Snohomish silt loam, thick surface variant------------------ 31 IIw-2 75 3w2 Su Sultan silt loam-------------------------------------------- 31 IIw-1 74 3w1 Tu Tukwila muck------------------------------------------------ 32 IIw-3 75 --- UrUrban land-------------------=------------------------------ 33 -------- -- --- ' Wo Woodinville silt loam--------------------------------------- 33 IIw-2 75 3w2 1/ The composition of these units is more variable than that of the others in the Area, but it has been controlled well enough to interpret for the expected use of the soils. 1 EXHIBTT "G" ' ASSESSOR'S MAP 1 1 1 1 1 SON,'Q CN"UN —� ]ty ��.R i0 » 0 S 14� 0 �Q ose ai - i k �� I;E r { e 4,{ ��,•w ... 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Simmler, Division Manager Russ Cahill, Division' Manager Jim Kramer, Assistant Division Manager Bill Jolly, Acting Division Manager Dave Clark, Manager, River R Water Derek Poon, Chief, Resources Planning Section Resource Section Bill Eckel, Manager, Basin Planning Program ' Larry Gibbons, Manager, Project Management and Design Section Contributing Staff Contributing Staff Doug Chin, Sr. Engineer Ray Heller, Project Manager & Team Leader Randall Parsons, Sr. Engineer Matthew Clark, Project Manager Andy Levesque, Sr. Engineer Robert R. Fuerstenberg, Biologist S Team Leader Bruce Barker, Engineer Matthew J. Bruengo, Geologist Arny Stonkus, Engineer Lee Benda, Geologist Ray Steiger, Engineer Derek Booth, Geologist Pete Ringen, Engineer Dyanne Sheldon, Wetlands Biologist Cindy Baker, Earth Scientist ' Di Johnson, Planning Support Technician Robert Radek, Planning Support Technician Randal Bays, Planning Support Technician ' Consulting Staff Fred Bentler, Planning Support Technician Mark Hudson, Planning Support Technician Sharon Clausen, Planning Support Technician ' Don Spencer, Associate Geologist, Earth David Truax, Planning Support Technician Consultants, Inc. Brian Vanderburg, Planning Support Technician John Bethel, Soil Scientist, Earth Carolyn M. Byerly, Technical Writer Consultants, Inc. Susanna Hornig, Technical Writer Virginia Newman, Graphic Artist Marcia McNulty, Typesetter Mildred Miller, Typesetter ' Jaki Reed, Typesetter Lela Lira, Office Technician Marty Cox, Office Technician P:CR 1 ' TABLE OF CONTENTS I. SUMMARY I II. INTRODUCTION 1 III. FINDINGS IN LOWER CEDAR RIVER BASIN 2 A. Overview of Basin 2 B. Effects of Urbanization 4 ' C. Specific Problems 5 1. Drainage and flooding problems 5 ' 2. Damage to property 6 3. Destruction of habitat 6 IV. RECOMMENDATIONS FOR ACTION 7 A. Reduce landslide hazards 7 B. Reduce erosion and flooding C. Prevent future erosion and flooding with appropriate analysis, g ' planning, and policy development D. Stop present (and prevent future) damage to habitat g by addressing specific problems in stream systems V. MAP 11 APPENDICES: ' APPENDIX A: Estimated Costs A-1 APPENDIX B: Capital Improvement Project Ranking B-1 APPEDDIX C: Detailed Findings and Recommendations C-1 ' I. SUMMARY The Lower Cedar River Basin, in southwest King County, is unique in its development pat- terns and the associated environmental problems that appear throughout the basin. Except for the city of Renton and areas on the Cedar River Valley floor, most of the development in the basin has occurred on the upland plateaus. Most of this development is recent and primarily residential. In addition, the plateau is the site of numerous sand and gravel mining operations and, in the southern uplands, an abandoned coal mine. Peat is also being mined north of Otter Lake. In some areas livestock are being raised on small farms; there are no major crop-related agricultural activities in the basin. The effects of development are most apparent where storm drainage is routed over the valley walls. Impervious surfaces on the plateau have increased the rate and volume of ' storm runoff, resulting in substantial erosion, siltation, and flooding below. In addi- tion, erosion and siltation have damaged or destroyed habitat in many tributaries, threatening the survival of fish. Habitat and water quality throughout the basin are also threatened by the filling of wetlands and the presence of large amounts of domestic trash in some streams. ' The reconnaissance team noted that the Peterson Creek system has so far remained in its natural, nearly pristine condition. Maintaining this quality should be a high priority in future basin planning capital project programs. Recommendations in the Lower Cedar River Basin include 1) designing and constructing appropriately sized R/D and other drainage facilities; 2) establishing stricter land use policies regarding floodplains, wetlands, and gravel mining; 3) conducting more detailed and comprehensive hydraulic/hydrologic analyses of proposed developments; and 4) preventing damage to the natural drainage system. The field team also recommends 5) restoring the habitat of several tributaries (e.g., cleaning gravels, revegetating stream banks, and diversifving streambeds for spawning and rearing) as well as 6) protecting the nearly pristine quality of Peterson Creek- , II. INTRODUCTION: History and Goals of the Program In 1985 the King County Council approved funding for the Planning Division (now called the Natural Resources and Parks Division), in coordination with the Surface Water Management Division, to conduct a reconnaissance of 29 major drainage basins located in King County. The effort began with an initial investigation of three basins -- Evans, Soos, and Hylebos Creeks -- in order to determine existing and potential surface water problems and to recommend action to mitigate and prevent these problems. These initial investiga- tions used available data and new field observations to examine geology, hydrology, and habitat conditions in each basin. Findings from these three basins led the King County Council to adopt Resolution 6018 in ' April 1986, calling for reconnaissance to be completed on the remaining 26 basins. The Basin Reconnaissance Program, which was subsequently established, is now an important ele- ment of surface water management. The goals of the program are to provide useful data with regard to 1) critical problems needing immediate solutions, 2) basin characteristics for use in the preparation of detailed basin management plans, and 3) capital costs associated with the early resolution of drainage and problems. The reconnaissance reports are intended to provide an evaluation of present drainage con- ditions in the County in order to transmit information to policvmakers to aid them in developing more detailed regulatory measures and specific capital improvement plans. They are not intended to ascribe in any conclusive manner the causes of drainage or erosion ' P:LC I f ' Lower Cedar River Basin (continued) problems; instead, they are to be used as initial surveys from which choices for subsequent detailed engineering and other professional environmental analyses may be made. Due to the limited amount of time available for the field work in each basin, the reports must be ' viewed as descriptive environmental narratives rather than as final engineering conclusions. Recommendations contained in each report provide a description of potential mitigative measures for each particular basin; these measures might provide maximum environmental protection through capital project construction or development approval conditions. The appropriate extent of such measures will be decided on a case-by-case basis by County offi- cials responsible for reviewing applications for permit approvals and for choosing among -competing projects for public construction. Nothing in the reports is intended to substitute for a more thorough environmental and engineering analysis possible on a site-specific basis for any proposal. �. F1NDINGS IN LOWER CEDAR RIVER BASIN The field reconnaissance of Lower Cedar River Basin was conducted in January 1987 by Robert R. Fuerstenberg, biologist: Brice L. Barker, engineer: and Lee Benda, geologist. Their findings and recommendations are presented here. A. Overview of Lower Cedar River Basin The lower Cedar River Basin is located in southwest King County and is 27 square miles in area. It extends southeast from the mouth of the Cedar River on Lake Washington to approximately river mile 14.0. The boundary to the northeast is marked by a ridgetop connecting the city of Renton to Webster and Franklin Lakes: the boundary to the southwest runs along Petrovitsky Road to Lake Youngs. Renton is the only incorporated area in the basin. Other population centers include Fairwood, Maplewood Heights, and Maple Valley. Except for the city of Renton, most of the residential concentrations are located on the upland plateaus overlooking the Cedar River Valley. These upland developments are recent compared to the smaller established communities on the valley floor. The basin lies within portions of three King Countv planning areas: Newcastle in the northeast (which includes Renton), Tahoma-Raven Heights in the east, and Soos Creek (the largest of the three) in the west. Rural areas exist on the valley floor on both sides of the Lower Cedar River, from approximately river mile 5.50 to 13.00. These are limited to pastureland for horses. cows, and some sheep and several small "u-pick" fruit and vegetable farms. Similar areas are located on the southern uplands above the reach from river mile 5.50 to 7.00 and in the Lake Desire-Otter Lake area. The plateau is also the site of sand and gravel mining operations and, in the southern uplands, of the abandoned Fire King Coal Mine. Peat deposits exist west of Lake Desire and north and south of Otter Lake, and peat mining is being carried out north of Otter Lake. Present zoning allows for urban and suburban densities throughout much of the basin, particularly on the upland plateaus and in the Cedar River Vallev from its mouth to appoximately river mile 6.50. Population projections for the year 2000 in the three plannign areas containing the Lower Cedar Basin are over '11.000. an increase of 47 P:LC � Lower Cedar River Basin (continued) percent from the present. Most of this growth will occur in the Soos Creek Planning Area. ' Dominant geological and geomorphic features. The geology of the Lower Cedar River Basin is diverse. Geological formations exposed along the valley include sedimentary rocks, undifferentiated older glacial drift, extensive ground moraine deposits, recent ' alluvium along the Cedar River, and landslide deposits along the river and its tribu- taries. The sedimentary rocks, composed of moderately dipping sandstones, con- glomerates, mudstones, and shales, are exposed locally along the cliffs of the Cedar ' River Valley near the mouth of the Cedar River. In addition, the Renton formation, composed of sandstones, mudstones, and shales with periodic deposits of coal, is also exposed along the lower portion of the Lower Cedar River Valley. ' Undifferentiated glacial deposits found here are composed of three or more till sheets, glacio-fluvial sand and gravel, glacio-lacustrine clav, and sand, and non-glacial sand, clay and thin peat. These lie over the sedimentary rock formations and are best exposed ' in cross-section along the cliffs of the main valley and major tributaries. The morphology of the Lower Cedar River Basin is dominated by the valley formed by the Cedar River. Vallev walls are steep cliffs formed by landslides in glacial sedi- ments. A once extensive and meandering River, which created a wide vallev floor as it cut its way westward, the Cedar today is diked for most of its length through the lower valley. A narrow but extensive band of landslide deposits exists along the steep cliffs of the main river and its major tributaries. The landslide deposits consist of deformed blocks of glacial sediments and colluvium derived from slides or mass flowage, such as landslides and debris flows. Recent alluvial deposits fill the valley and ' major tributaries. Small, composite, alluvial debris fans exist at the mouths of the' largest tributaries. Closed depressions, principally in the uplands, have lacustrine and peat deposits. ' The Lower Cedar River Valley has a high potential for erosion due to steep slopes and the existence of a clay laver that promotes soil failures. In addition. the confined nature of tributary channels between steep hillslopes promotes bank erosion' during high flows. Numerous recent landslides are evident along cliffs of manv of the steep tributaries and along the main stem of the Cedar River. These have been accelerated by the removal of vegetation and the routing of concentrated storm flows over steep tslopes in areas where development has occurred. Hydrologic and hydraulic characteristics. The Cedar River Basin is composed of a ' complex drainage network consisting of the Cedar River and 17 tributaries. The larger tributaries begin in lakes or wetlands on the bluffs and flow through relatively flat, stable channels to the edge of the Cedar River Valley, then plunge down to the vallev floor through steep, erodible ravines. Tributaries of this type such as Tributary 0304 ' (with headwaters at Wetland 3111) and Tributary 0323 (which begins at Lake Desire), are found on the south side of the Cedar River. Another type of tributary collects surface ninoff from urbanized areas, pastureland, and wooded areas. Tributaries 0302, 0307, and 0312 are examples of this type of tributary. Thev are intermittent (depending on rainfall), shorter in length, flow through shallower channels that are steeper at the bluffs and transport more material during times of ' P:LC 3 1 ' Lower Cedar River Basin (continued) high flows. Some of the worst problems located during field investigation (see Appendix C for a full listing) occur on this type of tributary. Catchments 5, 6, and 12 have very infiltrative soils. Urban developments hvae utilized R/D poinds to effectively infiltrate all urban runoff before it reaches the valley hillslopes. The infiltrated runoff then reappears as springs. ' Two large lakes (Desire and Otter), together with four smaller ones (Shady, Peterson. Webster, and Francis) lie in the southeast third of the basin. Numerous large wetland ' areas exist in this section as well. The field team identified 10 potential wetland sites that had not been previously identified in the Sensitive Areas Map Folio (SAMF). The system of lakes and wetlands in this area effectively buffers the high flows draining to these tributaries. Habitat characteristics. With few exceptions, usable fish habitat exists only in peren- nial streams (i.e., Trib. 0302, 0304, 0305, 0323, and possibly 0303). In other streams (e.g., Trib. 0303 and 0310), steep gradients preclude fish use. Steep gradients also reduce fish use in the perennial systems (except for Trib. 0323). Habitat is in various stages of degradation in these systems; pools are being filled and gravels and debris shift regularly. In Tributary 0323 (Peterson Creek), however. habitat diversity is extensive, and the channel is not seriously degraded. At this location the field team observed at least three species of salmonoids. ' In general, the most diverse and least disturbed habitat in a tributary system occurs in the large wetland areas in the southeast third of the basin. Usable habitat for anadromous fish is found in the low-gradient portions of streams where channels cross ' the Cedar River Valley floor. In these reaches, however. only spawning habitat is likely to be available, as the pools and woody debris necessary for successful rearing either do not exist or are quite limited. Excellent spawning and rearing areas exist ' where pools and riffles are extensive, instream cover and bank vegetation are intact, and diversity of habitat types is abundant. B. Effects of Urbanization in the Basin tFlooding, erosion, and the degradation of habitat associated with development in the Lower Cedar River Basin are most apparent where development has eliminated vege- tation along the edges of the valley and where stormwater has been routed down channels and swales. The removal of vegetation. such as trees. above and below the edges of valley walls, as well as the discharging of stormwater over the vallev wall. has resulted in tension cracks and landslides that are' endangering some houses. The sedi- ments from these failures are depositing in streams and on valley floors and damaging fish habitat and private property. Discharging stormwater from increased impervious areas into steep tributary channels and swales is seriously destabilizing channels and ' valley walls, this in turn results in channel downcutting, bank erosion, and landslides. The sediments from these problems often degrade fish habitat and settle out on pri- vate property along the valley floor. Two serious instances of development-related erosion occurred during the November 1936 storm: 1) culverts rerouting the stream were plugged, causing the formation of a new channel that destroyed portions of roads on Tributary 0314; and 2) new, uncom- P:LC 4 Lower Cedar River Basin (continued) pacted fill adjacent to new residences near collection point 5 was washed partly away during the storm, causing landsliding and gullving. Future problems will be similar to these, as commercial and residential developments increase flow rates and volumes by decreasing natural storage and infiltration. This is expected to occur if wetlands on the upper plateau are encroached upon or lost (e.g., on Trib. 0304 at RM 2.30 and on Trib. 0304A at Rm 1.60). The preservation of wetlands and streambank vegetation and the attenuation of storm flows are essential in this basin. C Specific Problems Identified The steep valley sideslopes through which streams pass and the often dense upland development result in a number of similar problems that repeat themselves throughout the Lower Cedar River Basin. The most significant of these are outlined and discussed below. 1. Drainage and flooding problems are often the result of several conditions: a. Undersized culverts and inadequate entrance structures. The most notable area is on Tributary 0306 at river mile .30, where a culvert here was blocked by debris carried downstream by the stream and caused erosion and flooding of Fanwood Golf Course. The blockage was compounded' by the fact that the culvert was undersized. the problem will worsen as flows increase from upstream development. ' b. Serious instream erosion and subsequent downstream sedimentation. These have been caused by three main factors: 1) runoff from residential developments on the bluffs above the valley, 2) compacted pastureland due to livestock, and 3) runoff from impervious areas originating at gravel pits. These problems will continue and worsen until mitigative measures are taken. (See Appendix C for specific examples.) c. Undersized rechannelized streams. Tributaries on the vallev floor are too small to carry the increased flows originating in developed residential areas along the top of the bluffs. For example, Tributary 0302 at river mile .25. ' the channel along Maplewood Golf Course, overtops and floods during storms. ' d. Construction in wetland and floodplain areas, Manv of the wetlands on the south side of the Cedar River are peat bogs, and roads built through them continue to settle each year, increasing the amount of flooding on the road. For example, the road crossing with Tributary 0323B north of Lake Desire will experience more severe flooding as the road settles. C. Discharging of stormwater at the top of steep banks. At river mile 2.20 on the Cedar River, a trailer park (constructed on the edge of the cliff) discharges its drainage down the vallev wall. Increased flows erode the steep valley, depositing sediments on the valley floor, blocking channels and causing flooding. These problems will eventually stabilize, but only after a large quantity of soil has been eroded. ' P:LC 5 Lower Cedar River Basin (continued) 2 Damage to property is being caused by three factors: ' a. Landslides and potential landslides. Landslides are accelerated by the removal of vegetation on steep slopes in preparation for residential construction and/or by the routing of storm flows over hillslopes. For example, a large landslide has already occurred in the front yard of a resi- dence on the Cedar River at river mile 7.80. b. Sedimentation (from landslides). Sedimentation and channel and bank ero- sion are damaging private property along the valley floor (Trio. 0299 and 0310). ' c. Flooding during storms. Flooding has been brought on by the effects of development and associated changes to the natural drainage systems in the basin. (See "B" above.) ' 3. Destruction of habitat is being caused by four conditions: a. Sedimentation of pools and riffles and cementing of gravels. These problems, the result of severe erosion and the transport of bedload material, have been caused by upland developments in the basin and the presence of associated impervious surfaces, which increase the rate and ' quantity of surface runoff. Sedimentation and cementing of gravels in streambeds destrov natural spawning and rearing habitat. On Tributary 0307 at river mile .40 and Tributary 0305 at river miles .95, 1.20, and 1.70. recent high flows have eroded the streambed at least one foot, contributing ' to a serious siltation problem downstream. Heavy bedload transport is evi- dent in all systems of the basin except Tributary 0328. In Tributary 0303 at river mile .25, fine sediments are accumulating in gravels that may be used by resident fish. In Tributary 0304 between river miles .95 and 1.20. pools are being filled by sands and gravels and rearing habitat is being rapidly lost. b. Channelization of stream beds. Loss of habitat through channelization has occurred in all the major streams of the basin, but most noticeably in those reaches that cross the valley floor. These reaches lack habitat diversitv. reducing fish use for spawning and rearing. Channelization has damaged or destroyed. habitat in several reaches that were once heavily used by fish; these include Tributary 0302 between river mile .30 and 40. Tributary 0304 between river miles .05 and .18, Tributary 0305 between river mile .20 and .75, and Tributary 0328 from river mile 1.10 to 1.40. These systems cannot afford a further reduction of habitat and still remain viable fishery resour- ces. ' C. The accumulation of trash in stream beds. This problem occurs in close proximity to residential areas. Trash degrades water quality and is visually ' unpleasant. Tires, appliances, furniture, and other trash have been thrown into Tributary 0302 at river miles 1.00 and 1.10 and in Tributary 0303 at river mile .35. ' P:LC 6 ' Lower Cedar River Basin (continued) ' d. Wetland encroachment. Encroachment destroys habitat and eliminates natural water filtration and storage for surface runoff. Examples of this problem were observed on Tributary 0304 at river mile 2.30, Tributary 0303 at .30, and Tributary 0304A at river mile 1.30. Many wetlands have already been completely lost through filling, for example on Tributary 0306A at river mile .55. Suspected violations were forwarded to Building and Land Development for enforcement. IV_ RECOMMENDATIONS FOR ACTION ' The primary recommendations for action in the Lower Cedar River Basin addresses current severe problems related to erosion, habitat destruction, and flooding. Prevention of these problems will be accomplished by controlling locations and densities of new development and ' providing adequate R/D facilities for stormwater. A_ Reduce landslide hazards by. 1. Including sensitive areas not previously mapped on the Sensitive Areas Map Folio (SAMF). See Appendix C for a full listing of sensitive areas. ' 2. Establishing building setbacks along cliffs and native growth protection easements along steep ravines. 3. Discouraging or eliminating the muting of stormwater over cliffs, unless adequate tightline systems can be constructed to convey flows in a safe, nonerosive manner to the bottom of cliffs. ' 4. Decreasing peak flows by constructing larger R/D facilities to lessen the landslide and erosion occurrence along tributary slopes. ' B. Reduce erosion and flooding in the basin by improving surface water management: 1. Direct the Facilities Management Section of the Surface Water Management ' Division to evaluate existing storm-detention and conveyance facilities to deter- mine whether they are properly sized to meet current standards. Evaluation should begin with all single-orifice R/D facilities. 2 Consider areas other than wetlands as regional storm-detention facilities_ Tributary 0300 at river mile .42 is the site for a proposed dam, for example. 3. Utilize existing lower quality wetlands (those rated other than #1) as regional storm-detention facilities. Wetlands 3102 and 3142 could provide more live storage, for example. 4. Review channel and culvert capacity for conveying existing and future runoff, and establish floodplain areas in regions of slight gradient for existing and future ' runoff conditions. 5- Promote the infiltration of surface water through the use of retention facilities and open channels instead of pipes where the soil and slope conditions permit. Collection points 5. 6, and 12 on plateaus have such soil conditions. ' P:LC 7 Lower Cedar River Basin (continued) ' C. Prevent future problems of erosion and flooding with appropriate analysis, planning, and policy development related to surface water management: ' 1. Conduct a detailed, comprehensive hydraulic/hydrologic analysis of any proposed developments to determine impacts on the drainage courses downstream. This is especially critical for areas on the upper bluffs and plateau, which drain over steep, sensitive banks above the Cedar River. 2. Conduct a study of the impact of locating infiltration ponds utilized near the edge ' of the bluffs to determine their effect on seepage faces on the lower face of the bluffs. This might be accomplished with a computer-based numerical model of the groundwater flow. ' 3. Require the tightlining of storm drainage down steep or sensitive slopes when they cannot be directed away from m the slopes. This is done by piping the flow down the slope and discharging it at the bottom with adequate energy dissipation. Manv of the intermittent tributaries flowing down the banks should be tightlined as urban development increases flow to them. ' 4. Construct new R/D ponds with filter berms to improve water quality and reduce fine sediment loads. New R/D ponds should have two cells with gravel-berm filters and vegetated swales at the inlet and outlet. Consider Tributaries 0304, ' 0304A, 0302, and 0303 as sites for this type of facility in order enhance water quality. 5. Maintain natural vegetation on streambanks and floodplains. This is especially ' important for relatively fl flat channels flowing on the plateau before they reach the steep bluffs because these channels and their oodplains will attenuate flows during times of heavy runoff. ' 6. Maintain buffer areas around wetlands. Many of the tributaries on the south side of the Cedar River headwater at wetlands. These wetlands act as natural storage areas during storms. 7. Reevaluate King County policy regarding permitting for gravel mining on steep, sensitive slopes. & Include the city of Rention in future interlocal agreements for planning and capi- tal improvement projects where city and county interests overlap. D. Eliminate present damage to habitat and prevent future damage by addressing specific problems in the stream systems. The following activities should be coordinated among King County, the Muckleshoot Indian Tribe, and State Departments of Fisheries and Game: 1. Reduce damaging storm flows with greater detention volume and lower release ' rates at upstream developments. 2 Implement restoration projects on Tributaries 0304 (river mile .00-.20). Tributary 0305 (river mile .20-.30), Tributary 0303 (river mile .25-.35), and Tributary 0323 (river mile 1.10 -1.40): ' P:LC 8 Lower Cedar River Basin (continued) ' a. On Tributary 0304: Clean streambed gravels, add habitat and bed-control weirs, and plant bank vegetation for shade. b. On Tnbutary 0305: Construct a new channel and move stream from road- side channel to its new location on adjacent lands. Implement a full restoration project to provide channel meanders, habitat structures, pool/riffle enhancement, streambed gravel replacement, and revegetation. C. On Tributary 0303: Move stream from present channel to a location further north, away from the roadside. If relocation is not possible, these minimum steps should be taken: Add habitat structure to existing channel with root masses, deflectors, boulder clusters, and other features; revegetate channel banks with shrubs and small trees; enhance stream crossings with bottomless pipe arches. d. On Tributary 0328 (Peterson Creek): Add habitat structure by replacing the straight, shortened channel with a more natural, meandering one: place habitat structures (such as root masses. deflectors, cover logs. and boulder clusters) throughout the channel; and revegetate banks with shrubs common to adjacent riparian zones (salmonberry, ninebark, or dogwood, for example). 3. Protect the Peterson Creek system (Trib. 0328) in its present, near-pristine state. ' This will include not only the restoration outlined in section A above, but also the adoption of land use management regulations to prevent future habitat destruction: ' a. Protect all existing wetlands within the subcatchments of Peterson Creek. Employ wetland buffers at least 100 feet wide without exception. b. Restrict development in the critical headwater area (drainage, habitat, water quality) bounded by Lake Desire, Otter Lake, and Peterson Lake to rural densities. ' C. Designate and protect streamside management zones of at least 100 feet from the ordinary high-water mark (OHWM) along the main stem of the creek. Use 25 feet from the OHWM on tributaries. ' d. Preserve floodplains and their forests for dynamic retention of sediments and water. C. Restrict vegetation removal in streamside/wetland management zones. f. Size R/D facilities to store the 100-year storm at a two-to-five-year release rate. Use the two-cell type of pond with a forebav, a gravel filter, and a vegetated Swale outflow where feasible. ' g. Regulate more closely all septic tank and drain-Geld installations, as well as maintenance schedules, particularly in the Lake Desire, Otter Lake. and Peterson Lake drainage areas. P:LC 9 Lower Cedar River Basin (continued) h. Work with the State Department of Ecology to establish minimum stream- flow requirements for Peterson Creek and Lake Desire tributary. 4. Develop and promote public education and involvement programs for basin awareness. Work with schools, environmental groups, and the civic and business communities to conduct educational and restoration programs. S P:LC 10 , i LOWER CEDAR RIVER BASIN nn�' . Basin Boundary T Subcatchment Boundary 2 Collection Point �E ,., � - ..' I ,� -- .✓ Stream 0299 Tributary Number 03115 Proposed Project I 0 2 Miles July,1987 O , x \I . apt i 19 .. LL 20 y O O r— 1� ,r y \ i3J09 wo w "7� O I ov 0 a 311 , , 3121 3118 wo 3122 1 3116 p3 1 O .. f' 1, e f 21 o M w a � v o �3�ry 3115 ntsrnr,lr.v� ,Ir.aw C31 O I I i e ' g Maple Valley 1 s APPENDIX A ESTIMATED COSTS: PROPOSED CAPITAL IMPROVEMENT PROJECTS LOWER CEDAR CREEK BASIN Indicates project was identified by surface Water Management office prior to reconnaissance. NOTE: All projects are located on map included in this report Project Collect. Number Point Project Description Estimated Costs Problem Addressed and Comments 3105' 10 Enhance 2200' of Trih. 0305 from Mitigates flooding $115,000 of King Cedar River to Elliot Bridge. County park land. (NOTE: This project was proposed by Surface Water Management, is in the design phase, and will be constructed by 1939.) 3109° 10 Secure casements to wetland located Better utilizes wetland's storage $136 000 in Cascade Park and construct a berm capacity to address peak flows from at the outlet. Replace existing surrounding urban area. catch basins with control structures. Project should he justified by a hasin study. Wetland rated #2. (This wetland will require further biological evaluation before R/D design and construction.) E P:LC.APA A-1 Project Collect. Number Point Proiect Description Estimated Costs Problem Addressed and Comments 3111 Secure easements to outlet to Francis(Wetland Will provide additional storage Lake and 1100' of channel from lake $175,000 3136 to mitigate anticipated future to SE 184th St. Construct a weir to increased flows. raise lake level F, and enhance 1100' of Trib. 0317. Should be justified by a basin plan. Wetland rated #1. ('Phis wetland will require further biological evaluation before R/D design and construction.) 3112 19 Secure easement for outlet to wetland Will provide additional storage (Wetland and replace existing weir with a $117,000 3142) for anticipated future peak flows. concrete-slotted weir. Should be justified by a Basin plan. Wetland rated #2. ("This wetland will require further biological evaluation before R/D design and construction. 3114* Secure casement to Wetland 3150 and Wetland Addresses anticipated increases in $134,000 ( construct a containment berm and flow caused by development. 3150) control structure at the outlet. Project should be justified by a basin plan. Wetland rated #2. ('Phis wetland will require further biological evaluation before R/D design and construciton.) 3115 18 Install detention pond and 1,000' Mitigates $361,000 severe erosion and of tightlinc. Project is indcpen- flooding during times of high dently justifiable. flows. P:LC.APA A-2 4 Project Collect, Number Point Project Description Estimated Costs Problem Addressed and Comments 3116 21 Raise existing road embankment Mitigates seasonal flooding of I-ake $73 000 2-4'. Project should be indepen- Desire Dr. SE caused by road bed dently justifiable. (Refer to settling in the peat bog. Roads Division.) 3117 16 Install 1,400' of tightline, a Mitigates severe erosion, sediments sediment trap, and 700' of channel deposited on County roads, and $501,000 from Jones Rd. to Cedar River. flooding during times of high Project is independently justi- flows. fiable. 3113 10 Install 300' of 36" culvert, a new Will prevent blockage of culvert inlet structure manhole and catch $37,000 and the accompanying flooding and basin. Project is independently erosion of Fanwood Golf Course and justifiable. mobile home park below. 3119 4 Construct a detention dam and Project location is ideal because control structure in a deep $159,000 it addresses flows from a large channelized section of Trib. residential area before they reach 0300. Project is independently the steep, sensitive area next to justifiable. the Cedar River. 3.120 15 Construct a -sedimentation and and P Mitigates flooding of residence and $163,000 1,000' of channel from Jones Rd. to sediment deposition on Jones Rd. Cedar River. Project is indepen- dently justifiable. 4 P:LC.APA A-3 Project Collect. Number Point Project Description Estimated Costs Problem Addressed and Comments 3121 7 Secure easement to wetland and con- Addresses increased flows in Trib. Wetland $371,000 struct a containment berm and concrete 0304 and 0304A from residential 3102) weir at outlet. Project should be Project developments. justified by a basin plan. Wetland rated #2. Biological assessment is needed to assure that this project does not decrease habitat values. 3127 ll Purchase existing ponds on rairwood Mitigates flooding and erosion Golf Course and expand to provide downstream. $34_,000 greater flow detention. Project is independently justifiable.. P:LC.APA A-4 APPENDIX B CAPITAL IMPROVEMENT PROJECT RANKING LOWER CEDAR RIVER BASIN Prior to the Lower Cedar River Basin field reconnaissance, 12 projects had been identified and rated using the CIP selection criteria developed by the Surface Water Management (SWM) and Natural Resources and Parks Divisions. Following the reconnaissance, 13 projects remain proposed for this area. They include eight new, previously unidentified and unrated projects. These displace seven previously selected projects, which were eliminated based on the consensus of the recon- naissance team. Projects were eliminated for several reasons: two sites were annexed by the city of Renton, two projects were found to be unnecessary, two sites were categorized as #1 wetlands (and are'ineligible), and one project was determined to be infeasible. ' The previous SWM capital improvement project list for the Lower Cedar River Basin had an esti- mated cost of $2,710,000, while the revised list increases to an estimated cost of $2,734,000. This 3 percent increase in estimated capital costs is due to the addition of projects after the reconnaissance. The following table summarizes the scores and costs for the CIPs proposed for the Lower Cedar River Basin. These projects were rated according to previously established SWM Program Citizen Advisory Committee criteria. The projects ranked below are those for which the first rating question, ELEMENT 1: "GO/NO GO," could be answered affirmatively. Projects with scores of 100 or higher can be considered now for merging into the "live" CIP list. RANK PROJECT NO. SCORE COST 1 3122 103 $342.000 2 3113 90 47.000 3 3120 75 163,000 4 3109* 67 186.000 5 3121 65 371,000 6 3117 60 501,000 7 3115 60 361.000 3 3116 55 73.000 9 3114* 23 134.000 10 3111* 25 175.000 11 3112* 17 117.000 12 3119* 15 159.000 13 3105 12 115.000 TOTAL $?7g4,000 * Projects proposed prior to the Reconnaissance Program P:LC.APB B-1 APPENDIX C DETAILED FINDINGS AND RECOMMENDATIONS LOWER CEDAR RIVER BASIN All items listed here are located on final display maps in the offices of Surface Water Management, Building and Land Development and Basin Planning Trib. & Collect. Existing Anticipated Item* River Mile Point Category Prop. Proi. Conditions and Problems Conditions and Problems Recommendations 1 5 Geology Gullying and landslides in Continued erosion. Recompact fill, revegetate, uncompacted fill in new and drain adequately. development near edge of steep hillslope. -- 18 Geology Small landslide has formed None (natural failure). None. debris flow (11/86). Sedimentation in yard of residence. .3 0299 4 Geology Landslides in sedimentary Natural failure. RM 2.6 None. rock in cutbanks adjacent to railroad. 4 0299 16 Geology Drainage from residential Increasing erosion. RM 9.65 o area is resulting in Provide adequate R/D to attenuate flows. gullying in Swale. P: LC.APC C-1 Trib. & Collect. Existing Item River Mile Point Anticipated Ca- ory Prop`Proi_ Conditions and Problems Conditions and Problems Recommendations 5 0299 18 Geology Horse farm in uplands has Continued high erosion and Develop R/D at horse farm RM 12.1 created extensive imper- sedimentation. to attenuate peak flows. vious surfaces, resulting See Project 3115. in channel scour, bank erosion, landslides, and sedimentation at mouth of basin. Residence overcome with sediment. 6 13 Geology Landslide terrain for sale Site of future mass erosion. Prohibit development here. by realtors. High risk for Notify Building and Land landslides, flooding (from Development. Add area to springs). SAME 7 -- 7 Geology Large-scale landsides g Natural process. None. adjacent to Cedar River due to springs and cutting of toeslopes by streams. Appears to be natural. 8 2 Geology Gullying in valley wall, Unknown. None. possibly from natural springs. 9 -- 14 Geology Landslide debris flow from Existing tension cracks residence on SE 147th PI., indicate future instability. ttrrees and shrubs.evegetate with Renton. P: LC.APC C-2 Trib. & Collect. Existing Anticipated Item River Mile Point Cate}7ory Prop. Proj. Conditions and Problems Conditions and Problems Recommendations 10 0299.1A 21 Hydrology 3116 Frequent flooding of Road located on top of peat Elevate the road 3-4' by RM .08 county road caused by low bog and will continue to filling on top of the road embankment. settle, aggravating flooding present road embankment. problem. Also stabilize embankment. 11 0300.00-.40 4 Geology Extensive channel and Problems will continue. Provide adequate R/D in RM bank erosion and numerous uplands. (See Project landslides due to 3119.) development-related stormwater. 12 0300 4 Hydrology 3119 Development-related peak Increased erosion on Construct detention dam in flows have caused sig. hillslopes below. deep, channelized reach of nificant bank erosion. Trib. 0300. 13 0300 4 Hydrology 3109 Collection point 4 has Degradation of Trib. 0300 Construct berm and standard RM 1.40 been nearly completely from RM .42 downstream. This control structure at outlet urbanized. section is very steep and to Wetland 3120 in Cascade susceptible to erosion. Park. 14 0302 6 Geology Channel downcutting and Will continue at same level Control storm flows from RM .50 bank erosion. or increase. uplands. 15 0302 6 Geology Bank erosion (medium den- Increasing erosion with Provide adequate R/D in RM .80-1.00 sity) at meanders and increasing flow from devel- uplands as area develops. obstructions. opments. P: LC.APC C-3 Trib. & Collect. ven Mile Point Category Existing Item Ri Anticipated Prop. Proi` Conditions and Problems Conditions and Problems Recommendations 16 0302 6 Geology Gully erosion from broken None. Culvert has been 17 0302 culverts. None. repaired. RM .60-.40 6 Geology Severe gully erosion Continued erosion. creating small valleys Tightline flows to from daylight culverts. main stem. 1s 0302 6 Habitat RM.35 Stream channeled along While fish now use this golf course road. No reach, lack of habitat will Add habitat diversity overhead cover. No habi- eventually reduce p p o ula- (e.g., structures, overhead tat diversity. tions. vegetation). Gain easement to restore mean- 19 0302 dens, if possible. RM .45 6 Hydrology Tributary drains down Problem will worsen as steep bluffs on north Construct detention dam development upstream upstream of golf course. side of Cedar River, continues. carrying debris and flooding Maplewood Golf Course. 20 0302 6 Habitat RM .50 Water supply dam. Full As impoundment fills, storm- b Dredge pond and maintain arier to upstream p water will flood over bank. it as sediment catch. Migration. Impoundment Structure may fail. is filling with sediment. 21 0302 6 Habitat RM .90 Severe gullying from right Will continue to erode until bank corregated metal reaches till layer. - Tightline downslope. pipe. Heavy sediment - Add velocity attenuator at delivery to stream. stream. P: LC.APC C-4 Trib. & Collect. Item River Mile Point Catc�o Existing Anticipated ry Pro_ p. Proj._ Conditions and Prohlems Conditions and Problems Recommendations 22 0302 6 Habitat RM 1.00 Trash in stream (auto, Area adjacent to corridor, tires, appliances). will continue to collect ' Remove trash. - Distribute educational trash and debris. Further worsening of water quality, materials to streamside q Y� residents. sedimentation, erosion. - Cite violators if problem 23 0302 6 Habitat persists. RM 1.10 Trash in stream. Water Area adjacent to corridor, quality problem, will continue to collect Remove trash. unsightly. - Distribute educational trash and debris. Further materials to streamside worsening of water quality. residents. Cite violators, if problem persists. 24 0303 6 Geology Extensive bank erosion in None. upper portions of tribu- Increase R/D volumes, slow release tary. rate to nonerosive levels. 25 0303 6 Habitat RM .25 Habitat suitable for resi- Sediments will eventual! dent fish. Sediment accu- Y - Control stormwater volumes cover gravels. habitat mutating. and discharge rates from will become unsuitable for developments. fish use. - Manually clean gravels when necessary, 26 0303 6 Habitat RM .35 Trash and litter in when decreases in water channel affecting water - Remove trash and litter. quality, causing erosion. quality. - Distribute educational materials to streamside residents. - Cite violators, if problem persists. P: LC-APC f C-5 Trib. & Collect. Existing Item River Mile Point Cate ory Prop. Proi. 27 0304 7 Habitat Conditions and Problems Condition Anticipated and Problems Recommendations RM .40 Landslides contributing Sediment will continue to sediment to channel. Heavy enter system until landslide with nsetbacks attain nleast 1150'r deposition in pools, at stabilizes. obstructions, even in from tops of banks. riffles. 28 0304 have access to 3 Habitat Horses h RM 2.10 Further decreases in water - Encourage residents to fence stream, causing some bank duality, bank erosion likely. channel back 15' from deterioration and possibly affecting water duality. high-water mark. ordinary Limit access to livestock to one or two points along stream. 29 0304 3 Hydrology Flooding 176th St. & 146th outlet structure s caused b failing RMProblem continue until - Problem referred to Main- 2.30 R/D at Ave SE. tenance section of Surface modified. Water Management Division. 30 0304 4 Habitat RM 2.40 Encroachment occurring Wetland likely to be - Require encroaching fills along all boundaries of reduced slowly until it is to be removed. this headwater wetland. completely destroyed. Loss - Establish specific buffer Of storage, filtration, around this wetland. organic production, and - Enforce sensitive areas wildlife habitat. ordinances and regula- 31 0304 tions. RM .30 7 Geology Several gullies due to Problem will continue. daylight culverts; a few - Tightiine drainage. have recent landslides. P: LC.APC C-6 rr r rr rr rr r rr r r r r r rr r r r rr rr rr Trib. & Collect. Existing Item Rive_ r Mile Point _Cateroiy Prop, prof` Conditions and Problems Anticipated Conditions and Problems Recommendations 32 0304 7 Habitat RM .00 Extensive riffle (to RM Gravels risk becoming .15. Crcek channeled. No cemented. Few restingareas - Enhance habitat by addi- woody debris, little bank for upstream migratingfish. Lion of woody debris in vegetation. Steelhead, stream. coho spawners here. - Revegetate bank. - Enhance pool/riffle ratio. 33 0304 7 Habitat Debris am may be a RM .20 1 Y Debris will continue to - Selectively remove debris partial migration barrier. accumulate. Channel will to allow fish passage. likely divert or jam will - Stabilize large woody fail, releasing accumulated debris. sediment. 34 03I04 5, 7 Habitat Debris jam. Bed dro s 3' P Debris will continue to - Selectively remove debris over jam and sediment, accumulate. Channel will to allow fish passage. forming anadromous likely divert or jam will - Stabilize large woody barrier. fail, releasing accumulated debris. sediment. 36 0304 7 I-Iabitat RM .80 Water turbid; oily sheen Water quality will continue and odor present. Storm to decline as runoff and Educate residents about ham' to maintain water quality. drains empty directly into waste enter stream. stream. - Mark storm drains with "Dump no oil" signs. - Emphasize recycling of oil. 37 0304A 7 IIydrology 3102 Existing RM 1.30 b forested wetland Additional storage could be Construct a proportional weir Provides detention for utilized by constructing Trib. 0304A and 0304 in berm and weir at outlet. Prject couldand berm at wetland outlet. heavily developed area. This could be done to atten- ofoProjectt 3107etosrpesecve insteadthe uate increased peak flows #1 rated wetland (where project as upstream area develops. would be built). P: LC.APC C-7 a Trib. & Collect. Existing Item River Mile Point Cate�o Anticipated rY Prop. Proj. Conditions and Problems Conditions and Problems Recommendations 33 0304A 13 Hydrology 3115 Runoff generated on top of Flooding will continue as RM .40 bluffs on southwest side - Construct detention pond long as land use remains the at top of bluffs. of Cedar River is causing same on top of bluffs or - Tightline drainage down severe bank erosion, until mitigating measures bluffs, then channelize it flooding and debris flows are taken. Runoff origin- to an existing ditch onto several residences ates from highly compacted alongside SR 169. of valley floor, pastureland on uplands.P - Prevent similar problems elsewhere with land use regulations, including provisions for preservation of vegetation buffers near tops of cliffs. 39 0305 10 Geology Extensive bank erosion, Susceptible to increases Attenuate high flows. partly due to subsurface with increasing storm flow. clay layer and landslide topography. 40 0305 10 Geology Local severe bank RM 1.10 erosion. Problem will continue. Existing rock-filled gabions are deflecting 41 0305 10 Geolog y flow. RM 2.10_ Extensive channel down- Continued erosion. cutting and bank erosion. Attenuate high flows with 1.75 adequate R/D. (R/D currently exists.) 42 0305 10 Geology Several gullies and asso- RM 2.15- �' Erosion will continue. Tightline culverts. 1.75 ciated landslides due to daylight culverts on steep slopes adjacent to chan- nels. P: LC.APC C-8 f Trib. & Collect. Existing Item River Mile Point Category Prop. Proi. Conditions and Problems Conditions andProblems Recommendations 43 0305 10 Habitat Madsen Creek in ditch along RM .20 Potential for fuel entry in- Acquire 30' easement away SE Jones Rd. Heavy silt; to creek. Further decreases from roadside. Construct road runoff; water quality in water quality can be ex- new stream channel. adversely affected. pected. 44 0305 10 IIabitat Creek in ditch along south Further decreases in water Acquire 30' easement away RM .35 side of SR 169. Heavy quality can be expected. from roadside. Construct inputs of oils, anti- Potential for autos to enter new stream channel. freezes, heavy metals, channel. Lack of habitat. organic pollutants likely. Sand, silt from roadside 45 0305 (of SR 169) enters also. RM .00- 10 Hydrology 3105 Section of Trib. 0305, Flooding will continue. _40 Construct and enhance 2200' of RM .00-.40 is experiencing (See Appendix A, Project channel through undeveloped extensive flooding. 3105.) King County Park Land. 46 0305 10 Habitat Channelized along dri- Further siltation, water RM .50 Acquire easement; move veway; lacks habitat quality degradation can be creek from driveway diversity. Driveway sedi- anticipated. Lack of habitat 10-15'. Add meanders and ments enter channel, and precludes optimum salmonid habitat structures to oil placed on driveway use, increase diversity, enters stream. 47 0305 10 Habitat Channelized tributary RM .65 Little s<�Imonid use Add structures to increase lacks habitat diversity, anticipated. Spawning and diversity in stream. cover for salmonids. rearing success limited Manually clean gravels by Gravels compacted. (unless reach is restored). churning them. P: LC.APC C-9 Trib. & Collect. Existing Item River Mile Point Cate-o iAnticipated ry _Prop. pro-. Conditions and Problems Conditions and Problems Recommendations 44 0305 10 Habitat Good spawning riffles occur Increased flows may cause RM .90 here. 1/2-3" ravels, few y Control flows into system el r►avcl bar movement. from developed areas fines, not compact. High Suitable gravels may be upstream. If necessary, flows are moving material, transported downstream to add bed controls to hold however. unusable areas for spawning gravels or "vee" struc- salmonids• tures to recruit them. 49 0305 10 Habitat Severe bank cutting and Further erosion/scouring can Control high flows by RM .95 erosion occurs here. Bed be expected. Channel p � increasing upper basin R/D scouring evident. Reach deterioration will continue. facilities, lowering subject to high, rapid Flows appear to be generated discharge rates to stream. flows. at developments. SO 0305 10 Habitat Much wood debris RM 1.20 y Debris jams will occur with Control upstream flows movement and numerous greater frequency as flows with greater R/D volume, debris jams. Reach is increase. Sediments will lower discharge rates. subject to high, rapid build up and channel will flows. divert. Selectively remove debris. 51 0305 10 Habitat Channel erosion, bank Further channel deteriora- RM 1.70 failures, downcutting oc- - Increase R/D capacity, o tion may be expected. Silt, - Decrease discharge rates. curring. Reach subject to sand transport to mainstem high, rapid flows. will increase. 52 0306 RM .40 10 Geology Failure of manhole during Not applicable. Repair manhole. 11/86 storm has resulted in gully erosion. P: LC.APC C-10 F Trib. & Collect. Existing Anticipated Item River Mile Point Category Prop. Proj. Conditions and Problems Conditions and Problems Recommendations 53 0306 10 Geology Channel downcutting, bank Erosion will increase. Clay Further increase in runoff RM .20 erosion and several layer in valley makes area should be attenuated; this landslides, due both from sensitive to landslides. is a sensitive channel. increased storm flows and development along edge. 54 0306 10 Geology Undersized culvert in arti- Possible fill failure: Lake Enlarge the corregated RM .30 ficial fill in golf course ponded behind culvert in metal pipe and/or threatens to build lake and in 1931 and threatened construct adequate trash Possibly overtop bank. the fill. rack. Breach flood possible. 55 0306 11 IIabitat Channel subject to high, Further channel damage can Increase R/D capacity, RM .25 damaging flows. Erosion be expected. Sediment decrease discharge rate. evident. transport downstream will continue. 56 10 Geolog RM .30-.45 y Downcutting, bank erosion Will continue or increase in Attenuate storm flows. RM and landslides. future. 57 0306 Hydrology 3118 Trib. 0306 connects with Problem will worsen as RM .30 - Replace existing pipes large tributary at manhole development upstream with larger diameter pipes here. Debris from 0306 continues. p (if downstream analysis clogs this manhole, causing allows for increased flows). severe erosion of Fairwood - Install new inlet struc- Golf Course. tures with trash racks. 53 0306A 11 Hydrology 3122 Existing small ponds on Area upstream is developing - Acquire easements for ponds RM 1.30 0306A are overtopped and quickly, thus worsening the and additional area around ponds receive considerable silt problem. and construct detention pond, during high flows. The - Location is ideal for addressomg ponds are located on peak flows before they reach Fanwood Golf Course. the sensitive Cedar Reiver bluffs. P: LC.APC C-1I Q S S = = = M M M M = = M ' i M i M = S Trib. & Collect. Existing Item River Mile Point _Prop. Proj. Conditions and Problems Conditions and Problems Recommendations 59 0306A 11 Habitat Some usable habitat exists Further habitat deterioration - Increase R/D capacities. RM .25 for resident salmonids. likely. Channel erosion will - Decrease discharge rates. Water quality is poor. increase. - Encourage use of 2-cell Channel subject to high detention ponds, swales. flows. - Prohibit filling of existing wetlands, ponds in upper basin. 60 0307 12 Geology Extensive bank erosion at Increased erosion will RM .10-.40 lopment- all meanders and obstruc. result with increased flows. - related hi heflows. tions (trees, cars) due - Provide adequate R/D. to increased flows from development. 61 0307 12 Geology Stream eroding toes of Increasin erosion with RM .10-.60 g - Mitigate development slopes resulting in increasing flows. related high flows. landslide failures. - Provide adequate R/D. 62 0307 12 Habitat Stream channel pushed to Erosion will worsen as - Increase R/D capacity at RM .30 one side of ravine for stream flows increase. roadway. High energy all delivery points. Y b gy May threaten Reduce release rate below road bank at - system. Much bank cutting, toe of slope. channel scour level. sediment transport, debris movement. 63 0307 13 Hydrology Area on top of bluffs near Infiltration sites should RM .60 Construct retention faci- Trib. 0307 has excellent be used whenever possible. lities for new develop. infiltrative capacity. These would provide ground- ments in area at these sites. water recharge. P: LC.APC C-12 Trib. & Collect. Existing Item River Mile Point Category Prop. Proj. Conditions and Problems Conditions and Problems Recommendations 64 0309 15 Habitat Subject to heavy, ra id RM .10 P Erosion, deposition will - Control storm flows flows. Channel erosion, increase. Sediments will upstream. deposition bars migration. migrate downstream, creating - Control volume and discharge a water quality problem. rates. 65 0310 15 Geology Sedimentation upstream from Continued sedimentation.RM .60 - See "Hydrologic and hydraulic culvert due to debris and characteristics" section in undersized culvert. New this report. corregated metal pipe con- tinues to pass water through. 66 0310 15 Geology Severe erosion below RM .05 Continued erosion and - Install energy dissipator culvert, severe sedimen- sedimentation. below corregated metal pipe. tation in residence yard. - Excavate channel through yard where original channel was located. 67 0310 15 Geology Road drainage forming gully Continued erosion. RM 1.50 adjacent to road; road bed Reroute drainage. Refer problem in danger. to Roads Maintenance. 63 0310 15 1labitat 3120 Corregated metal pipe is Problem will continue. RM .25 Reinstall corregated metal anadromoi►s barrier. pipe at or below bed level. P: LC.APC ` C-13 M S M M M M M ! M M M M M ! M M M M M Trib. & Collect. Existing b Anticipated Item River Mile Point Catego ry Prop. Proi. Conditions and Problems Conditions and Problems Recommendations 69 0310 15 Iydrology 3120 Existing channel draining RM .40 o Frequency and severity of Construct detention pond off bluffs on north side problem will worsen as on upstream side of Jones Of Cedar River, causing development on bluffs Rd. to trap sediments, and flooding of residences and increases. enhance 1,000' of creek debris flows onto Jones Rd. from Jones Rd. to Cedar during peak flows. River. 70 0310 15 Habitat Corre ated metal RM .60 g pipe Problems will continue and Remove new and old pipes; outlet approximately worsen as outfall velocities replace at lower level 9' above bed level. will scour bed and banks. with oversized pipe with Complete barrier to fish. Upstream has recent (11/86) trash rack. Old culverts at bed level deposition up to 4' deep. are plugged. 71 0311 13 Geology Gully erosion in drainage Continued accelerated ero- RM 1.70 swale due to outflow of sion. If possible, enlarge R/D wetland that partly seems prior to its outlet in the to act as an R/D facility. wetland. 72 0314A 16 Hydrology 3117 Severe erosion, flooding, RM .20 ng, Problem will be aggravated - Tightline drainage between damage to County and as area above develops. detention ponds in gravel it, private roads from P increased runoff from - Construct detention pond gravel pit operations on next to Jones Rd. to trap hillside. sediments. - Construct channel from Jones Rd. to Cedar River. 73 0314A/ 16 Geology Inadequate R/D, plugged Not applicable. 0314BSee hydrology comment culvert caused by exten-RM .10-.40 sive channel and bank above. erosion and landslides. Water has cut a new channel. P: LC.APC C-14 a = M = = = = M = M M = = = = = M M Trib. & Collect. Existing Item River Mile Point Cate�oiy _Prop. Pro'` Condit ons and Problems Condi on-s and Problems Anticipated Recommendations 74 0317 Hydrology 3111 Francis Lake is only RM 1.60 Y Trib. 0317 flows through - Construct proportional hydraulic control for steep area downstream of Trib. 0317. weir at outlet. lake. If area around Francis - Enhance 1,100' from Lake develops, increased Francis Lake to SE 184th St. peak flows could cause severe damage to Trib. 0317 in the steep region. 75 0320 Hydrology 3114 Existing forested wetland RM 2.40 If surroundingarea urban- with large amount of un- If this would re a good Construct containment berm utilized storage. Wetland site to attenuate peak and control structure at currently detains flows on flows. p outlet of wetland (if bio- Trib. 0320. logical analysis permits). 76 0313 19 Habitat Salmonid parr in man YRM .10 Decrease in water quality Establish and maintain Pools. Large pools up to with increasing develop- adequate buffers, 100, 1.75' deep. Some deposi- ment. Loss of habitat. tion in ool behind from ordinary high-water obstructions. Decrease in fish use. mark or 25' from top fo slope break, whichever is greater. 77 03,82 19 Habitat Salmonid use apparent from System is most) in natural RM .35 carcasses. Sockeye, Y - Maintain adequate stream Y', condition. As development corridor buffers. Chinook spawners. Some increases, higher flows and - Reduce discharge rates to sedimentation occurring. worse water quality can be pre-development levels. expected. Prevent clearing, grading within buffers. P: LC-APC C-15 = = = = = M = = M Trib. & Collect. Existing Item River Mile Point Category Prop. Proi. Conditions and Problems Conditioned and Problems Recommendations 78 0328 19 Geology Medium-density landslides None. RM .50 and high-density bank Limit development in the basin. erosion occurring due to natural causes. This indi- cates channel and valley sensitive to effects of development. (Sensitivity due to clay layer. Basin hosts some of best fish habitat in upper reaches.) 79 0328 19 IIabitat Significant s<1lmonid use Sedimentation from upstream Maintain leave strips RM .70 throughout. Sockeye reach possible. Adjacent adjacent to stream at spawners, carcasses present. development will likely least 100' from ordinary Coho, steelhead parr in reduce diversity and duality high-water mark. Restrict pools. Excellent habitat of habitat. use/development within this for spawning and rearing streamside management zone. (a redd site). Much diversity -- most exemplary in basin. Channelized reach. Uniform May cause thermal problems Restore stream habitat 80 0328 19 Habitat channel, no habitat diver- as water temperatures rise. throughout: add structure, RM 1.10 sity. Heavy sand deposition. No useful habitat. 1.40 diversity, bank vegetation, Little overhead canopy or and canopy. Cost should be bank vegetation. borne by party(ies) who channelized this reach. 81 0328 19 flydrology 3112 Lake Peterson is small, Lake provides good peak flow Replace weir at outlet RM 1.40 open-water wetland with a attenuation and will become with a higher weir in weir at outlet. more important as upstream order to gain additional tributary area develops. storage. P: LC.APC C-lb f EXHIBIT "P' SOILS REPORT 1 1 1 1 1 1 1 1 EXHIBIT "J" SENSITIVE AREAS FOLIOS 1 1 1 1 1 1 1 1 i 1 ij y i 1 � >i t r ''�:. may!• 1 �:- 's! t l l T s hi- till t�'... ...� lkb i t _T. 1 , { I.. f!2I`1I -- s rut t / ! �, dive areas dis- See wetlands and landslide hazard maps for �=� ����� approximate. additional potential seismic hazard areas. �eis rm that have not Wetlands and landslide areas are susceptible e5ent on a devel- to failure during earthquakes. Other seismic Areas Nhere differences hazard areas not shown on this map are traced on these shorelines underlain by lacustrine sediments; fire actual pre- these are susceptible to liquefaction. r)f the 5e n5i tive Sensitive Area I. 1 1/2 0 1 MILE ��1HAV� SEISMIC HAZARD AREAS NORTH SOURCE: 1990 KING COUNTY SENSITIVE AREAS FOLIO L.L s f Zz s I. I I ` a v if 1 „ \ One- hundred-year floodplains extend be- Class 1 DuwamiSh yond those shown on maps. Flood In streams and 100- •-•-•-o-� Class 2(with salmonids surance Rate Maps do not always show the Year �N g� 1 ( ) loodplain to the headwaters of streams. y eal 1 loodplainS - i 1 Class 2(perennial;salmonid 2* :t3; use undetermined) Class 3 g 114;: • • • • • s 100 Year Floodpia[ns 10_ Unclassified sue11_ — — •1 1"2 1 vz o 1 MILE - - STREAMS AND FLOOD HAZARD AREAS ' NORTH SOURCE: 1990 KING COUNTY SENSITIVE AREAS FOLIO IL , ir N. .r. LLJ Cc �; U •�-, 1 �I � ,t ' I 7 � •""'»11 I J 7 { lil F r ` ` �' 1' ��^+r!�0 y�'�� ,� �.�.l.- I ire\ � J' 1► .'1'v*"P.' , y '�p,�r'i i } � z Il co Cc liv >k i L 1 i >'I A ui iYh..E"� 4 � , r -% ,.F.'�-._' t i a:. {.Y`•� I"'"L.t .�,�..�,-�+- � �� _ 7 � y� -p m�'—' www.ww w w■wson wtL"ANIa14=3. `rrc vsl�, y .ate -ww.a � ';��wcrte av�.►�-rsc- �i yr " t � �t« ■ www/■I' t d € i gl��fi s11-rwrw��a. �r � ✓�, _ MW YYt � ��xf -"rim kq TRA Rm MDR w in Suo- rib, `, .i �iif� ■ �' e rplif h 5 a aerCR► In Ulu g ON gill all mi �! -, ;- lipw -` WPM WIN SHE Ali ily ��� � Iv uE ` ' �,� vp _ _�ii� �: s.�i,���!��A►���--"_����� � f�. �ai1�A�iR���r�ef��g�. ��- sty ,;«►✓`!�: s, f �, ,. a �_��_t_-�—� �,' ,��-� \ _,j,� y'--:-,•:' �.aF'- > r _ y r Oil e•. .J � ✓ \\ !! 3cr, LU M - 1 � � � o.. ♦ .w��+''f t � iw'`I ? +a eat k �� �, It � ... '' I, ..� 11'' °"-1 `• „r� ,�`:':` r, ;, r �,.,.' a 2 lY-k' �t xM / . .I I /a•,';�i, �' IL M��` r� ,y._.,,,.1. �VM�✓�+�K'..x�,: :!F S./� / 1. /�;�A1h7�1-�� .mil .� j h .L1--�-i. .._.� ��,.•: +�n� I••,Y''' �^�-fi'4�'a�,' i x � � :� �t'•I••i<-�'I :'I'-�-�(-�'�'�v `+<,�t i j f, ' --vU I ,.:.r•aK°y '',+.m9' ✓r 1 r E I R r,�S W r Sr t .3r\-'6"Y°t•ttndy?e' -' �0<�' �t �1 d-� `� � rs^h 4� r� •+_ t I "` t•�cr3, i.� `*dw"�' t�- -' -r a .;rr t a�,,Fvx,,,.:sq,.a I, �' „r �+ •'�'� i Ifyl ,R*. 0�...1:_? .....� ^-;. ,l4 I.,.,,��-• 1 �1�'"`•w,�_l Lv..."._�. •'" 1,..Iy R..'" I, ;s4' :z .i... ♦// •w+I- �,•,,,,�d�^""-... I� E ., � � s + ,<�} rg� ;4 }��,,.. f� IK,�� � f s F�� ,1,t � I �' / ���;ix• t�/ z O Ar LL cc CO :.1..: .` r /,�; 1 ��' �y1 s••� '� _r1 i I �,.,,...v:�'L..�, '.h:�_'`._`f ' 1 f lid i I�I II /rr n. Q O JJ r mc 'o'°'0 L -. r.i • „,, r 3 ,'� t 4 }"Wr. .w. ° " -'4".�.: I,'tri '-Lam.... .i:.- n,n...° m,. C7 • . +�.�:-�.._„ 1 ,.e..�'..♦�'M ,, �' I ]' �_.""_ 1 �'E I 4 1 ,�S�"•,a •J""t7��• ., - ro 13 s 4 } �`} � i jS- �l. M "•tea:. �'` rn �,r'1 ,. .-n*, t� :.b•,»� I 't I III ,�,u�. r r t.. %� , �t'�L w a' •- l� ° LLJ Ifill". � 0.cc '`i ¢ t IT y. •....,....A«.,,a+•,:e•F::. �.Y•r-•t� —f-",c -X f. r., A�a ..•. -..Y.r ,�L '. ." ;,c•^U:l y_ ��i.•;...�.p.:r ..._ _. - .1--1L- '.I. . - .I .�-r. I 1 "�� .a rt.. 't ..4� - t. t� _C L a 3.+. :.',4. - -, 4 Y I '' I V +L r•. fi r_ C O c L,C� •nU� , I -IruA�+ �" ._+. _ ,�..,.�-.;. ' ,y- _ r �_---t�' t�.t T':•l,�.l 1'"1'I"� i •� �� �Y` � �`• � .i y `. ate\ } �` �. ' Vl �. �I LL ` " _ J Lt 1� I 2 4� 75, t f a- 1 fflTin ; r' i .f r•-3 f p." r :i.�" _ i - -_,, t+ �i`., ' s y �t, i• i \i , ;�� f� ..A 1� ts A R i q Le 1 y l: `a t e - yl 1 LS I \ J i y �9 :f� ' I I J �'. F 25 � �- S] _ +uer- 9 '•. v nsiti•ve areas dis- Nu,;, eyed avetlands, except those 4vit ar. Wetlands �r--� Wetiands re approximate. "a" br "b" desi99r:atio- are included in the that have not Ki!zg Coun:`v 1t'Ftiands Inuentory. The sent on a Bevel• Ixations of wettards designated "a" have Open Water 1.here differences been verified on the site by a variety of illustrated on these sources. 'Wetiands designated "b" are map- s,the actual pre- ped in the U.S. Fish and ;Nildiife Service ��� Basin Boundaries e cf the sensitive National Wct!ands Inventory, but Their loca- Sensitive Area tions have not teen field verified. Sub-basin Boundaries trcl. There may be gaps in the numbering se- ouence within individual drainage basins. 1 1/2 0 1 MILE �CyHAG�� - - WETLANDS NORTH SOURCE: 1990 KING COUNTY SENSITIVE AREAS FOLIO CIVIL- SITE PLAN ,x SITE I; I-' $ 13 ASPHALT ; '� I „f z AIRPORT :• t ~`' 18 L/S -BUILDING ENCROCHMENT I 1 1 i 17 ID M: ... 1 C 4 LOT LIGHT � EXISTING BUILDING i i o ' '�' 4 LOT LIGHT l 22 APP ROACH AIRPORT WAY S. 1 "=20' M TCH EX. 101' - - � 1 1 0 1 _ II --- rr 11 DEWALK -- - ----- �I V., - -------- ---- ----- - - - - 0 10 20 40 N/ s - CUR � n yt:� ��,5� 12 CURB ASPHALT 13 NEW WATERMA{N ESMT. 12 � ' ._ 0 .... ... .. - C HEE C2If SON FEE• U o > "' SEES T - :. o REN O Fti: I e ( 18' R R=2 5 TRASH ENCLOSURE 42.4:; r ASPHALT `ices •• 13 q � nn � • L- L_t_ , o I ........ .. 13 ASPHALT 13 �-' a a t '',Y =': I I: ASPHALT � ' R=20 Z _ 0 I / 0 CONC. t ,.... �+► n -�--- Z i : 15.�'' S.5 SW ALE _ co r v 15 11 S _J --- ----- �� 2c► 10.29' 12' ° , 3 ASPHALT Z _ ��-- { I ° �. ° VICINITY MAPI` � o 1 11 I V, U n --------------- OW € p SIGN ° i. PROPERTY LINE € ARR m L Q II m �' I .� / AND BUILDING I' ='_ W I i 18' ' ` 6 CD x ; °°. O II �' � ,�.. .. '"` I' SETBACK LINE . 111 � _ � : : „ N 23 °FRB •Y �. SIDE DEVELOPMENTSCHEDULE } I 4 i1) �.� In e i 0- �_ ;, N CURB 12 ► 'li E ) ii i 3�, 8 ° ° 1 NEW AM/ MMINI-MARKET (3600 RECTANGLE BLDG. UBC TYPE VN. SEE ARCH. PLANS Al-1 m �� IN U f, 18 L/S ' RAMP y T A l ` - PER DETAIL 2-1 i RANT NEW HANDICAP ACCESS RAMP '•' EX. UNDER GROUND ' - - 11 EX. FIRE HYDRANT • 2 Q 0 TYP. ° "� REMAI -1. -4- TO O=1 POWER B (TYP.) r :. , o t; a 15' 12.5' 3 H.C. PARKIN �"' -� ONEW HANDICAP PARKING SIGN AND PAVEMENT SYMBOL PER DETAILS 4 AND 5/AS2 MOUNTS ON BLDG _ u ;; I :crds. n' 31 41 3.5' -1 `; SIGN v W U I is• > �t 18' t • ' 40' z , , 18 L/S ', s 4 NEW LOT LIGHT PER DETAIL 7/AS2-1 (HIGH LEVEL TYP. OF 5). MOUNTING BASE TO ;; i ° 3LDG. N a ° ° C �� tt Yvr '�A7... BE SET 3 CLR. OF CURB. (1000 WATT METAL HALIDE LAMP). •_ CUR 12 TIE Ik : 30' 18 6' } 6_- CONC. S/W L :CANOPYI a o (�J 5 NEW 13'-4"x10'-2" TRASH ENCLOSURE W/CONC. PAD PER DETAIL, SHEET AS2-2. C/L II SAWCUT 13 € 2! BLD _ 8 PI 13 ASPHALT CD "'' �`' B SIGN C TYP. ° ° ° 48.35' ° a �XISTING CURB ' 6 NEW 4" THICK CONCRETE SIDEWALK (WIDTH AS SPECIFIED ON SITE PLAN). +� Q� O ASPHALT FCn SAWCUT r ���j j "° • I JJ GUTTER, AND SIDEWALK w w II' �, 1 NEW AM/PM I ,� ._. ° � I`• ; 7 NEW 41 x I - MINI-MARKET 'I " ' ' 18' S" ISLAND CANOPY WITH EIGHT -0 x4 -6 PUMP ISLANDS, ELECTRONIC _ r m ' O MULTIPRODUCT DISPENSERS AND I.I.P. SIGNAGE.11 NON-ILLUMINATED FASCIA (PREFABRICATED) ED .. .: l 11; ` `� , ,�, - r- .Z� R-2 ° " `: ...:IQ �' �' ';,_ ':'�. �' ES OF CANOPY. CONSTRUCT 48'x124'-6" REINFORCED CONCRETE SLAB CENTER U Q n:1 I s ° o I I ON ALL SIDES ' ° - - , '' ' 1, '� ,, �'' NOPY ALL PER DETAILS, CA1-1, CA1-2, CA2-1, CA2-2, AItiD CS 1-1 THRU CS2-1. - ------ a ��� 11: T�., y., BENEATH CA 3 .:,fl ASPHALT 13 r (1) ® °° 18' rn N ° EX. TEL'1 HOME SOX ' ° e FOR FUTURE PIC EQUIPMENT. SEE CANOPY DRAWINGS. INC'_UDE CONDUIT TO LOT LIGHT 7.5 yy .. OBUILDING.� STUB UPo - - I TYP. OF 2 DOUBLE SIDED UNITS = 4 TOTAL) a+� Ln ._ �� CANGPY I ° /�r /._.... ( D SIGN ;r; 11 1 ;;% I ° 20,00 AL COMPARTMENT 12,000 10,000 GALLON rn 22 APPROACH 1, NEW (1) ISINGLE 0 GALLON AND (1) DU / 3 5' ° :; VI'C ° • '` � ' GROUND GASOLINE STORAGE TANKS WITH REINFORCED CONCRETE SLAB CENTERED B - ° © ° OVERT TANKS. INSTALL PER "WET HOLE" INSTALLATION SPECIFICATIONS. SEE I- 19 ° ASPHALT 16 STALLS ° (' ° ° tWAL m _ a nP. ' ° CURB 12 "` DETAILS SHEET TK1-1 THRU TK4-3. °' ° -•- O CONC • • � � '` � ''I�'"'�`%� '' -' ii 10 N THREE VENT RISERS FOR UNDERGROUND LINE STORAGE TANKS. SEE TANK PLANS. • -0�'-! W �, F H 15 SWALE R=20 0 ° > " PER �C `,1 I "• « ;'\jf- ° N 6 CONC. S/W V¢, LD• ��' s ./i'/r �� „ , i i;�.�'1 .,tti w w w 0_4 Y� 18 L/S A SIGN 11 NEW 40 �:80 x4 THICK CONCRETE PHONE BOOTH PAD P DETAIL 8/AS2-1. �_T.------ .° ,' '� .•i NEW CON • I N D�:)HON ' CRETE CURB AND GUTTER (ON-SITE) PER DETAIL 1/C4-1.AD °° ° .. Z s, ! I i,M; O E U� �� ° DOA O �o �/ v ',. r ,, '6_, -. i".'` tl / Q V/ E 31 a 18 L/S A. F O °° ` �'.' ' `' ; 13 NEW ASP'IALT PAVEMENT PER DETAIL 2/C4-1 a, ASPHALT 13 AIR ATER N , , .• I ° C14 21 .. ° �' Al ° °a ; / N ! 3 %` 14 NEW AIR/WATER DISPENSER W/TWO GUARD POSTS PER DETAIL 9/AS2-1. -+--� -.� C Q, I�..: I UNIT . ° _ R=20 ;; •:' N CAR °o :! o O . a F!`' pr' i �\ l ,. AIL 4 C4-1. • - ;, SAWCUT - _-, ° ___ ° ND SLAB PER DETAIL we ` .. . - - 15' J R=3 /, '"�� i :�+ WASFI,BLDG ; ° P�� 15 NEW CCF,,RETE GUTTER SWALE ALONG PUMP ISLAND / - `P' �" \ h D � . / /'r•-,/` e 16 PARKING STALL MARKING SHALL BE 4" WIDE WHITE STRIPES TO DIMENSIONS SHOWN. U LOAD 48 '<;!'---. 26 �� S� INSTALL ER BP STANDARD SPECIFICATIONS. -__ , •.......:. ° UNLOAD �;.,;;',�, ,'` w LL SAWCUT O �' '' '� 9 00 TANKS %' SF-F ,,;'! - / 17 PEDESTRIAN ACCESS PAINT MARKING SHALL BE 4 WIDE WHITE STRIPES O 2 O.C./45' ANGLE. I \ 15 �• R=15' % ;- f,, ' ! INSTALL PER BP STANDARD SPECIFICATIONS. LL 4p� r ! Z 18' 6' 15 9' 9' R=2' ' ,+ - ,' t Itx , t 8 LANDSCAPE PLANTER AREA. SEE SHEET L1-1 FOR PLANTING PLAN. o I �'I 22 APPROACH r*` �....... . Z 1 t. I t e \ • 2 RAMP 18 L/5, O- 19 NEW CONCRETE CURB, GUTTER AND SIDEWALK (OFF-SITE) PER CITY OF RENTON STANDARDS. ' ,_ . ' • F R=3 G R`s/ o,�` 12 CURB �' SEE DETAIL SHEET C4-3. • ° GINSTALL TYPE 1 PAINTED DIRECTIONAL ARROW PER WSDOT STD. PLAN H-5c. ^ 17 STRIPING Q �- r,I± � , I ,�r•- >- cc) 12 CURB CUR 12 DEPR R=20 ,- r 0It ° Q CURB 23 ,- 19 / \ o E I a Lam..w w 0 13 ASPHALT CON f 21 NEW CAT! WASH BLDG. (22 x44 ). SEE ARCH. PLANS CW1, CW2, AND CW3. % c- z 4 LOT LIGHT SWAL • ;�;`. O II I, o 2 RAMP ,: VENTS 13 ASPHALT 22 NEW 6" THICK CONCRETE DRIVEWAY APPROACH (ALTERNATE 2) PER RENTON STANDARDS. Q 12' 4' 12' 12' 4' 12' �'" f G SEE DETAIL SHEET C4-3. _ ! ,! 4 LOT LIGHT (� °i R=2� R=2 r P OSSIBLE EXISTING 18" STORM LINE 23 NEW 1" HIGH DEPRESSED CURB FOR RAMP ACCESS. 0 •D R=5 Z 11 W i 7.5' \ R=1O' 12 CURB i�� r R=30' r :�; 20 ARROWS PER 1962 CITY UTILITY MAP. ° 24 NEW VACUUM UNITS (4 EA) SUPPLIED BY OWNER. PROVIDE (2 EA.) 3'Wx10'Lx4" THICK I l i . . 20 ARROWS / \� / EXACT LOCATION UNKNOWN. CONC. PADS FOR MOUNTING VACUUMS. REFER TO MANUFACTURE'S SPECS. FOR ° 22 APPROACH MOUNTING INSTRUCTIONS. nl (, O - tI t \ �" `O 25 NEW HANDICAP RAMP PER DETAIL 2/AS2-1. W VAC U U M 24 VAC VAC VAC VAC 6 a' C�� J . PROJECT SIGNAGE SCHEDULE 0 .- P , I , CONC. , :-- , 'S ��G��J� / W/150 S.F. 26 STALL TO BE MARKED FOR LOAD/UNLOAD ZONE AS REQUIRED BY CITY. Z U ° 'L O MAXIMUM NEW SPECIAL FACE AND CE I 40' MAX.EHE HEIGHT (BY SIGN CRNALLY DONTRACTOR) PER DETAIL, STRIPE PER NOTE 17 ABOVE. 1 , °''. VACUUM 24 .�O/ G� _ G V p SHEET SNA1 1. R C° t ',` ,'%, B NEW AM PM FASCIA SIGN, INTERNALLY ILLUMINATED, (BY SIGN CONTRACTOR), LEGEND : s a 1i ; { ''�°� 19 G _• O PER DETAIL SHEET A6-1. - -71 a 1t ° LATCH EX. E :< :x> S ='; s;- �\ V "SPARK" Q� .,. V O NEW ARCO SPARK LOGO SIGN, INTERNALLY ILLUMINATED W/10.56 S.F. SIGN AREA, PROPOSED ASPHALT PAVEMENT SIDEWALK fi , ' ,' !' P (BY SIGN CONTRACTOR) PER DETAIL SHEET CA 2-1 (TYP. OF 4). uJ Q ' I i 15' BSBL ,;�°� PROPOSED CONCRETE L; o I t: L I:, F ., D NEW ADVERTISING SIGN, INTERNALLY ILLUMINATED, W/41 S.F. SIGN AREA, '1 (BY SIGN CONTRACTOR) PER DETAIL SHEET A6 1. (TYP. OF 2). `1' " I ' `� ~ NDI.D./PRICESIGN, EXTERNALLY ILLUMINATED, W/ EXISTING CONCRETE tb G`T�NC y N t } Ir, r - EX. UNDER GROUND NEW SPECIAL S G E N 54"W / O 150 S.F. MAXIMUM TOTAL FACE AND 40' MAX. HEIGHT (BY SIGN CONTRACTOR) PER DETAIL, .., t�0 - _______ _ _ __ POWER BOX (TYP.) 1 �i�t ° �, "'9 // SHEET SNA1-1. EXISTING CURB AND GUTTER -uNo PLANNING AND DESIGN SPECIALISTS- ' +t`' \� `` i'..:�a`d'f ��• / w w �,.Nllt D .� ni \ `\ ^r�< W/3.2 S.F. SIGN AREA, 1KENT 7 AS AVENUE SOUTH ? I ° :, OF NEW AM/PM SPARK LOGO SIGN, INTERNALLY ILLUMINATED, -- _ (BY SIGN CONTRACTOR) PER DETAIL SHEET CWA.2 (TYP. OF 3). KEN(42sj 251 60�298032 �, ,��, ,L:�t�; EX. STREET A A PROPOSED CURB AND GUTTER l r�` !'-,' ' LIGHT (TYP. O NEW "CAR WASH" SIGN, EXTERNALLY ILLUMINATED, W/13 S.F. SIGN R , eg'v F� consultant job# PROPOSED LOT LIGHT ©O 7816 19 (BY SIGN CONTRACTOR) PER DETAIL SHEET CWA.2. (TYP. OF 1). I I IUD dr I�, UtJbC' U LU �`fi;y O NEW "ENTRANCE" SIGN, EXTERNALLY ILLUMINATED, W/3 S.F. SIGN AREA, `✓ (BY SIGN CONTRACTOR) PER DETAIL SHEET CWA.2. (TYP. OF 1). PROPOSED SIGN �.. NEW -EXIT- PER DETAIL SHEET CWA.2. P. OF1). xe date drawn y :�• : �: : / O N T" SIGN, EXTERNALLY ILLUMINATED, W/3 S F SIGN AREA project d master b ' (BY SIGN CONTRACTOR) (N ,I BY PROJECT RELEASE zo I OJ NEW ADVERTISING SIGN, INTERNALLY ILLUMINATED, W/12 S.F. SIGN AREA NO REVISIONS { P GR� (BY SIGN CONTRACTOR) PER DETAIL SHEEP CWA.2. (TYP. OF 2). y Filename �P 1 2-28-02 PERMIT RESUBMITTAL OL PERMIT - WG c�F WAsy B� Facility/Project 6530 BID . -oZ CONST. sheet nam�tte /1J ' C/SCI L .TOP ONA L E 4•l j' - - '^1d AS-BUILT I ; EXPIRES 6-10-03 III B 10535 1 SE E 3 2002 o SCANNED P 1 to