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Home My WebLink AboutSWP272855 �errn � Poo 31 � - Short Plaa t' SHPL iff' ) REQUEST FOR PROJECT i f Prclim Plat (PP# ) CAG ) To: Technical Services Date a WO# (p d Green# From: Plan Review/Project Manager Jrj n _ I I ici n Project Name e �( n e— P,k : tV a c I Vf�!.-►� C70 characters n=) I vc,th �,_ Description of Project: u- M i -I cs --kc 04� t(,Q b u d d wq � ` � � W. �� 1� �fw�� agm L- , o-F 19�` �f m ��I Z I �' o �' �'` 1n1 hulk-t �ae art Vod-e Circle Size of Waterline: 8" 10" 12" Circle One: Mew or Extension Circle Size of Sewerline: 8" 10" 12" Circle One: New or Extension Circle Size of Stormline: '8")12" 15" 18" 24" Circle One: ce-w or Extension Address or Street Name(s) ' 5Z)a I` oy)Ql 1 a y e C,W Dvipr/Contractor/Owner/Cnslt:: 60!Sh _/I�OCCJ 1- Lh -milIOP — �pcainC Y-S (70 charade ) Check each discipline involved in Project Ltr Drwg #of sheets per discipline Trans-Storm - (Road way(Drairugc) (Off site improvemcnts)(ineludc basin name) (include TE.SC sheets) O Transportation (Sig alization,(hartnclizadon,Lighting) ❑ ❑ l� Wastewater �Q ] sanitary Sewer Main(ircludc basin name) Water (Maus,valve,Hydrants) (Include composite L:Horizontal Cui SlIecu) l}9, Suface Water ❑ Improvements (CLP ONLY)(includc basin name) TS Use Only 7-ED -40- ;Z S55 l�Z-a�55 wwP 3C1 - aS55 Vw-T - 'Al- -L�<6-s s vy - a SV,3 a-7-a�s5 _ F LR a-� - ag55 STORM DRAINAGE REPORT D FOR BLACKRIVER RIVERTECH LOCATED AT POWELL AVENUE SW NORTH OF SW 7TH STREET RENTON, WA F1 N D FOR APR 18 2000 BUILDING DIVISION BLACKRIVER RIVERTECH, LLC. BY Ronald G. Goldy, P.E. APR 1 7 2000 BUSH, ROED & HITCHINGS, INC. LPN Architects & Planners 2009 MINOR AVENUE EAST SEATTLE, WA 98102 (206) 323-4144 Q. �' BRH JOB NO. 99196.01 G�~ DATE: April 17, 2000 � �L�GI0703��v �sv' 4-. 1'7.�a I aLR11 12/I/d f U00 I w �1VQ 'l�CC1 TABLE OF CONTENTS • Page Project Overview 1 Core Requirements 2 Special Requirements 3 TI R Worksheet 4 Storm Drainage Calculations 6 Appendix A. Drainage Maps • PROJECT OVERVIEW The project site is located at Powell Avenue SW, north of SW 7"' Street, in Renton, Washington. The 5.0 acre site is currently undeveloped except for a paved access road to the existing Rivertech I development to the west. The existing surface consists of dense shrubs and trees. The site is generally flat with storm ditches and wetlands within the northern half of the site. The proposed Rivertech development consists of a new 13,141 s.f. building with associated parking, landscaping and utilities. Approximately 0.76 acres of new impervious area is proposed. The existing dense shrubs and trees will be removed within the project limits. A 25' min. and 50' avg. setback will be provided between the existing wetlands and the proposed new building and paving. Approximately 840 s.f. of wetlands will be filled, but is within the 10% threshold of wetland removal, per NWP Permit#1999-4-0044. Detention will not be provided at noted within the following Core Requirement#3. Water quality will be provided via a coalescing plate oil/water separator for the parking area around the building and a bio-filtration swale for the parking area to the west. These will discharge into the existing biofiltration swale previously designed for this development along the south property line. Erosion and sedimentation control measures will be implemented during construction activities per City standards. The following sections address the projects compliance with the storm drainage Core and Special Requirements as outlined by the City of Renton. • CORE REQUIREMENTS i1)_ Discharge at a Natural Location The proposed drainage system discharges to the natural site discharge location. An existing ditch within the western portion of the site conveys runoff from properties upstream of the site, including approximately 4.0 acres developed area from the adjacent Rivertech I site to the west. Runoff from the site and upstream properties is collected by an on-site ditch which outlets into an existing 8" dia. storm drain which discharges into an existing 36" dia. culvert along the south property line. This culvert outlets westerly into the existing biofiltration drainage ditch along the south property line of this development and ultimately reaches a fore-bay of the P-1 channel. 2) Off-Site Analysis Runoff from the site and upstream properties is collected by an on-site ditch which outlets into an existing 8" dia. storm drain which discharges into an existing 36" dia. culvert along the south property line. This culvert outlets westerly into the existing biofiltration drainage ditch along the south property line of this development and ultimately reaches a fore-bay of the P-1 channel. The P-1 channel is ultimately pumped by the City of Renton to Green River. 3) Runoff Control The property is part of the original Black River Corporate Park Plat. According to the plat agreements (as discussed with Michael Dodson of the City of Renton Engineering Dept.), storm drainage from the plat property would be discharged undetained into local surface ditches which outlet into a fore-bay of the downstream P-1 channel. The P-1 channel is ultimately pumped to the Green River. A coalescing plate oil/water separator is proposed to treat runoff prior to discharge from the site. 4) Conveyance System All storm conveyance pipe will be sized to accommodate a 25yr/24hr storm event. 5) Temporary Erosion and Sedimentation Control Erosion control measures such as perimeter filter fabric fencing, quarry spall construction entrances, interceptor ditches, sediment traps, etc., will be provided according to City requirements. 6) Maintenance and Operation Maintenance and operation requirements for the permanent storm drainage facilities will be provided with the final construction documents. 7) Bonds and Liability Bonds and Liability requirements will be addressed during the final permit process. • SPECIAL REQUIREMENTS 1) Critical Drainage Areas • The project is not within a City designated critical drainage area. 2) Compliance with an Existing Master Drainage Plan There is no known Master Drainage Plan for this project although the proposed drainage system complies with the intentions of the original Blackriver Plat. 3) Conditions Requiring a Master Drainage Plan There is no known Master Drainage Plan for this project. 4) Adopted Basin or Community Plans The project is not within an Adopted or Community Plan. 5) Special Water Quality Controls Since the proposed impervious area subjected to vehicle traffic is less than one acre, special water quality controls do not apply. 6) Coalescing Plate Oil/Water Separators The project proposes to use a coalescing plate oil/water separator for water quality control per Section 3 of the Core Requirements. The project does not propose petroleum storage or • transfer, high vehicular use (>2500 trips/day) or heavy equipment use, storage or maintenance. 7) Closed Depressions The project is not within a closed depression. 8) Use of Lakes, Wetlands or Closed Depressions for Peak Rate Runoff Control Detention and peak rate runoff control is not required as discussed in Section 3 of the Core Requirements. 9) Delineation of the 100 Year Floodplain According to the 1995 FEMA (provided within Appendix A), the site is within the 100yr floodplain (EL=15.0). Our proposed finished floor elevation has been set at 16.00 (1.0' above the FEMA flood elevation). 10) Flood Protection Facilities for Type 1 and 2 Streams The project does not contain or abut a Class 1 or 2 stream. 11) Geotechnicai Analysis and Report Although a geotechnical analysis and report is not required according to threshold criteria identified within the section, a general soils analysis will be provided with the construction • documents. 12) Soils Analysis and Report A general soils analysis will be provided with the construction documents. Page 1 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PROJECTPART I PROJECT OWNER AND PART 2 PROJECT LOCATION DESCRIPTIONAND Project Owner A l pe or Alo r 0 W ti"S V► C ; Project Name Address }CtG s tfe , (CAD, Pc,�f('E q?/Q`l Location Phone Cm:td> '+' Township a �Or'ca (o( C-r C Range K Project Engineer ��!o(y Section 12 Company kO project Size AC Address Phone BOG y rl='�dr r¢ve Upstream Drainage Basin Size AC (-I r '-� -q 0 q`f PART 3 TYPE OF • OTHER Subdivision DOF/G HPA Shoreline Management Short Subdivision 0 COE 404 Rockery Grading DOE Dam Safety 0 Structural Vaults ® Commercial ® FEMA Floodplain Other Other — 0 COE Wetlands HPA COMMUNITYPART 5 SITE DRAINAGE Community Drainage Basin PART 6 SITE CHARACTERISTICS River _ Floodplain 0 Stream Wetlands Critical Stream Reach Seeps/Springs Depress i o ns/Swales F--1 High Groundwater Table Lake Groundwater Recharge ( V ps-4 reek EST ' "NIl e Steep Slopes — Other Ct r c A, Lakeside/Erosion Hazard SOILSPART 7 Soi ype Slopes Erosion Potential Erosive Velocities • 1 I Additional Sheets Attatched 1/90 Page 2 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET REFERENCE LIMITATION/SITE CONSTRAINT Ch.4-Downstream Analysis I / a a 0 a Additional Sheets Attatched PART 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING 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 Clearing and Grading Restrictions Ensure Operation of Permanent Facilities Cover Practices Flag Limits of NGPES Construction Sequence Other Other PART 10 SURFACE WATER SYSTEM Grass Lined Channel = Tank Infiltration Method of Analysis Pipe System 0 Vault Depression -L��;H, 0 Open Channel = Energy Dissapator 0 Flow Dispersal Compensation/Mitigation 0 Dry Pond 0 Wetland Waiver of Eliminated Site Storage Wet Pond = Stream 0 Regional Detention Brief Description of System Operation (�� /J/C r' `` R% '�' 4-f ' V�'y Facility Related Site Limitations 01 scha'j e to l o c e / d l fc tl. 0 Additional Sheets Attatched Reference Facility Limitation / a �/ - _ specialPART 11 STRUCTURAL ANALYSIS PART 12 EASE MENTS/TR ACTS (May require .:Drainage Easement [71 Cast in Place Vault 0 Other 0 Access Easement 0 Retaining Wall 0 Native Growth Protection Easement Rockery>4'High E::] Tract Structural on Steep Slope 0 Other PART 14 SIGNATURE OF -• • I or a civil engineer under my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the i attatchments. To the best of my knowledge the information provided here is accurate. S19 d'O'°' 1/'90 4/17/00 10 :47 : 57 am Bush, Roed & Hitchings, Inc page 1 RIVERTECH II S : \WORKS4\99196 .BSN by: PAD --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: 100e NAME : 100yr existing SBUH METHODOLOGY TOTAL AREA. . . . . . . : 5 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : KC24HR PERV IMP PRECIPITATION. . . . : 3 . 90 inches AREA. . : 4 . 76 Acres 0 . 24 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 .00 TC. . . . : 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 1 . 64 cfs VOL: 0 . 95 Ac-ft TIME: 480 min BASIN ID: 25e NAME : 25yr existing SBUH METHODOLOGY TOTAL AREA. . . . . . . : 5 .00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : KC24HR PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 4 . 76 Acres 0 .24 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 . 00 TC. . . . : 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 1 .29 cfs VOL: 0 . 77 Ac-ft TIME: 480 min • BASIN ID: 2e NAME: 2yr existing SBUH METHODOLOGY TOTAL AREA. . . . . . . : 5 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : KC24HR PERV IMP PRECIPITATION. . . . : 2 . 00 inches AREA. . : 4 . 76 Acres 0 . 24 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 . 00 TC. . . . . 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 .43 cfs VOL: 0 . 31 Ac-ft TIME : 480 min • • OIUWATER SEPARATOR • • 4/14/00 3 :48 :46 pm Bush, Roed & Hitchings, Inc page 1 RIVERTECH II • S : \WORKS4\99196 .BSN by: PAD BASIN SUMMARY BASIN ID: 100dev NAME : 100yr developed - w.q. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .31 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : KC24HR PERV IMP PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0 . 00 Acres 0 .31 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 .00 TC. . . . . 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 30 cfs VOL: 0 . 09 Ac-ft TIME : 470 min BASIN ID: 2dev NAME: 1/3 2yr developed - w.q. SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 31 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : KC24HR PERV IMP PRECIPITATION. . . . : 0 . 66 inches AREA. . : 0 . 00 Acres 0 . 31 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 . 00 TC. . . . . 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 04 cfs VOL: 0 . 01 Ac-ft TIME: 470 min • 660-CPS • OIL / WATER SEPARATOR 788 SQ.FT.-EFFECTIVE COALESCING AREA 415 G.P.M.-MAXIMUM PROCESS FLOW COVER 4'-8" ;_ No.64-2-342P _;!=, =1 '�'=11,_ 1,200lbs. -1 1I1�1 1�111�1l1'1'1- 6'-8" _ -I-I-I-I- -I-I-I-I- -1-I-I I-I-I-I-I-1-I-I-I-1-I-I o'- I-I-I-I-I-I-I-I-1-I-I-I-I-I I-I-I-I-I-I-I-I-I-I-I-I-I-I-Ii-T_-Ty��'' -I-1- -I-I-I-I- -I-I-I-I-I-I-I- -1-1T-1 i-I-I-I-I-I-I- -I-I- - -I-I-- - -I-I-I -I- I-I-I-I-I- -I-I-I- -I-I-1-I-I-I-I-I-I-I- -I-I- -I-I-I-I-I- -I-I-I-I- -I-I-I-I-I-I-I-I -I-I-I-I-I- - -I-I-I- -I-i-I-I-I-I-I- -I-1-I-I-I- -I_I_I_I_i_I-I-I-I-I-1-I-I-I-I-1-1- -I-1-I-I-I-1-I- 1-1-1-1-I-I-1-I-I-1-1--I-I T I-1-1-I-I-i-I-I-I-I -I-I-I-I-I-I-I-I-I-I-I-I-I- 1_1_1_1_I_I_I_I_ -I-I-I-I-I-I-I-I-1-1-I-I- I-i-I-I-I- -1-I-I-I-I-I-I I-I-I-I-I-1-I-I-I-I-I-I--I-I---I---I I-I-I-I - -I-I-I - --1---- I-I ----II-I--II--I-II-II--1I--II-I-I - - --I-I--I-1--I-I--I-I-I--I-I--II-1-I-i-I-I--I-I-I-- 1I---I-III--I-- -- - ----------- - - T_ --I-I- -I-I I-1- TIT,-- -----I---- - - ---- o I-I-I-I-I-I-I-I-1-1-I-I-1-1-I- I-1-I-I-1-I-I-I-I-I-I-I-1-I -I-I-I-I-1-I-I-1-I-1-I-I-I- OUTLET PIPE —I—�Ii 41T-ii�i�i�i�—I WITH SAMPLING TEE —1-I-I-I-1-I-1-I- I-I-I-I-I-I-I BY OTHERS —I-I-I-I- - FIBERGLASS HOLD-DOWN CHANNEL BASE ASSEMBLY \ No. 660-CPS - 6,300 Ibs. 6 0" OUTLET WEIR _ � INLET PIPE a WITH ELBOW OIL RETAINING BAFFLE ;. BY OTHERS f D •.ii'M# 4'hV W Yr Y r %a S xis ->Fcv.s.�a fr r.. o o s�- i� 6'-0° D 0 COALESING MEDIA 4'-0 INLET WEIR • * ITEMS SHOWN ARE SUBJECT TO CHANGE WITHOUT NOTICE. FOR DETAILS SEE REVERSE SIDE. Copyright 1992 123 Issue:April,1992 660-CPS . OIL/ WATER SEPARATOR 788 SQ.FT.-EFFECTIVE COALESCING AREA 415 GPM-MAXIMUM PROCESS FLOW 6-8" 6'-0"-VAULT F- 9 ' U.V.Co.2-342P PLAN VIEW DIAMOND PLATE COVERS FIBERGLASS HOLD-DOWN CHANNEL 1 " -' _ OIL RETAINING BAFFLE FINISH GRADE EL. --�— — OUTLET PIPE INLET I.E. —— 1Ll WITH SAMPLING TEE BY OTHERS INLET PIPE I I �_ — OUTLET I.E. WITH ELBOW BY OTHERS o - D I I I a D (D 4'-0" o WATER DEPTH 0 D INLET WEIR D 0 COALESCING MEDIA SECTION AA OUTLET WEIR STRUCTURAL NOTES: INFORMATION NEEDED: 1.CONCRETE:28 DAY COMPRESSIVE STRENGTH Pc=4500 psi INLET PIPE SIZE- 2.REBAR:ASTM A-615 GRADE 60 OUTLET PIPE SIZE- 3.MESH:ASTM A-185 GRADE 65 GRADE ELEVATION- 4.DESIGN:ACI-318-83 BUILDING CODE INLET INVERT ELEVATION- ASTM C-857"MINIMUM STRUCTURAL DESIGN OUTLET INVERT ELEVATION- LOADING FOR UNDERGROUND PRECAST CONCRETE UTILITY STRUCTURES" 5.LOADS:H-20 TRUCK WHEEL w/30%IMPACT PER AASHTO BASIC DESIGN INFORMATION: • GENERAL NOTES: INFLUENT CHARACTERISTICS- 1.ALL BAFFLE/WEIR PLATES TO BE MILD STEEL,GALVANIZED OIL SPECIFIC GRAVITY=.83 2.WATER DEPTH=4'-0" OPERATING TERMERATURE=45' 3.CONTRACTOR TO: INFLUENT OIL CONCENTRATION=100 ppm GROUT IN ALL PIPES MEAN OIL DROPLET SIZE(MICRONS)=130 SUPPLY&INSTALL INLET&OUTLET PIPES(INCLUDING PIPE ELBOW&SAMPLING TEE) FLOW EFFLUENT FILL w/CLEAN WATER PRIOR TO"START UP"OF SYSTEM RATE QUALITY VERIFY ALL BLOCKOUT SIZES and LOCATIONS 4.REFERENCE U.V.Co.CATALOG MODEL 660-LA 125 GPM 10 ppm 123.1 BIO-FILTRATION SWALE • 4/14/00 3 :49 :27 pm Bush, Roed & Hitchings, Inc page 1 RIVERTECH II . S : \WORKS4\99196 .BSN by: PAD ------------- BASIN SUMMARY BASIN ID: 100dev-w NAME: 100yr developed - bioswale SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 10 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : KC24HR PERV IMP PRECIPITATION. . . . : 3 . 90 inches AREA. . : 0 . 00 Acres 0 . 10 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 .00 TC. . . . : 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 09 cfs VOL: 0 . 03 Ac-ft TIME: 470 min BASIN ID: 2dev-w NAME: 2yr developed - bioswale SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .10 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : KC24HR PERV IMP PRECIPITATION. . . . : 2 .00 inches AREA. . : 0 . 00 Acres 0 . 10 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 . 00 TC. . . . : 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 05 cfs VOL: 0 . 01 Ac-ft TIME: 470 min • • • Mannings Open Channel Flow Equation -For Biofiltration Swale Design -1990 King County Method Capacity (CFS) Form of Equation: 1.49/D8*(D9*D10+D11*D10^2)*((D9*D10+D11*D10^2)/(D9+2*D10/@SIN(@ATAN(1/D11))))AO.667*D12"0.5 0.0501721 CFS (Input these Variables) n= 0.35 (Required by King County) b1= (ft) 2 (Minimum Bottom Width) d= (ft) 0.1421082 (Maximum = 0.333) ss= 3 (Maximum side slope of Swale) s=(ft/ft) 0.02 Swale Slope Velocity (FPS) Form of Equation: 1.49/D20((D21*D22+D23*D22A2)/(D21+2*D22/@SI N(c@ATAN(1/D23))))^0.667*D24^0.5 0.1455105 FPS n= 0.35 b1= (ft) 2 d=(ft) 0.1421082 ss= 3 s= (ft/ft) 0.02 • Required Swale Length (1-1)= 200 feet Compensation for shortened swale: Site does not allows for the required length of swale: therefore, adjust for a shorter swale length (1-2) Top width of water surface in Biofiltration swale (T1) = b1 + 2*(3*d) T1 = 2.8526491 Feet Required surface area (SA) = T1 * L1 = SA = 570.52982 Square feet For a shortened swale length (1-2) = L2= 120 (Input this variable) Adjusted swale top width (T2) = SA/1-2 T2= 4.7544152 Feet Adjusted Bottom Width (b2) = b2= 3.9017661 Feet • • CONVEYANCE PIPE 4/17/00 10 :25 :0 am Bush, Roed & Hitchings, Inc page 1 RIVERTECH II • S : \WORKS4\99196 .BSN by: PAD BASIN SUMMARY BASIN ID: 25d NAME: 25yr developed SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 62 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : KC24HR PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 15 Acres 0 .47 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 83 . 00 98 . 00 TC. . . . : 50 . 00 min 6 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 .42 cfs VOL: 0 . 15 Ac-ft TIME: 470 min • CONVEYANCE SYSTEM DESIGN Project Name: Rivertech il, Renton,WA By: A:T M. Project Number: 99196.01 Date: 4/17/00 DRAINAGE CRITERIA: 1998 King County Surface Water Design Manual RAINFALL METHOD: Rational Method DESIGN STORM: 25YR t 24HR FROM TO A C CA CAtot Tc I Q C61 VAULT 0.47 0.90 0.42 0.42 6.O 0.4 0.18 DIA n s Qf Vf Q/Qf L. 12 0.012 0.0050 2.76 3.5 0.06 10 PIPE DIA. (FT) = 12 SLOPE (FT/FT) = 0.005 N = 0 Q = 1.49 X A X R12/3 X S^1/2/ N = 2.76 CFS • S�I�S GRb.�PS KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL • (2) CN values can be area weighted when they apply to pervious areas of similar CN's (within 20 CN points). However, high CN areas should not be combined with low CN areas (unless the low CN areas are less than 1 5% of the subbasin). In this case, separate hydrographs should be generated and summed to form one hydrograph. FIGURE 3.5.2A HYDROLOGIC SOIL GROUP OF THE SOILS IN KING COUNTY HYDROLOGIC HYDROLOGIC SOIL GROUP GROUP* SOIL GROUP GROUP* C Orcas Peat D FAlderwood C Oridia D Arents, Alderwood Material B Ovall C Arents, Everett Material C Pilchuck -C Beausite D Puget D Bellingham D Puyallup B Briscot D Ragnar B Buckley Renton -D Coastal Beaches Variable Variable Earlmont Silt Loam D Riverwash C Salal C Edgewick A/B D Everett 'Sammamish D Seattle Indianola A D Kitsap C Shacar C Klaus Variable Si Silt • Variable Snohomish D Mixed Alluvial Land A Sultan C Neilton D Tukwila Newberg B Urban Variable Nooksack C D Normal Sandy Loam D Woodinville HYDROLOGIC SOIL GROUP CLASSIFICATIONS A. (Low runoff potential). Soils having high infiltration rates, even when thoroughly wetted, and consisting chiefly of deep, well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. ls erate on B (Moderaconsisting tly low runoff ch chiefly of moderately)fineot10 moderatelydcoarse telxtur'es. rates thoroughly soils have moderate ate of water transmission. C. (Moderately high runoff potentiai). Soils having slow infiltration rates when thoroughly wetted, and consisting chiefly of soils with a layer that impedes downward movement of water, or soils with moderately fine to fine textures. These soils have a slow rate of water transmission. D. (High runoff potential). Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a hardpan or clay layer at or near the surface, and shallow soils over nearly impervious material. These soils have a very slow rate of water transmission. • From SCS,TR-55, Second Edition, June 1986, Exhibit A-1. Revisions made from SCS, Sol Interpretation Record, Form #5, September 1988. 11M 3.5.2-2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.2B SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type 1A rainfall distribution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SO GROUP LAND USE DESCRIPTION A B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed or older second growth 42 64 76 81 Wood or forest land: young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area 68 80 86 90 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 • Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 98 Open water bodies: lakes, wetlands, ponds, etc. 100 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre % Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, % impervious condominiums, apartments, must be computed commercial business and industrial areas. (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm system. • (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. l 3.5.2-3 11/92 • • • • Sm al do bill O VA's all 1 • • imp ► ' ff .9are r CD ll � • w��►ter; r 1 1 ns5 all Il �r FAF., N � .• ii ST UVOT-M! �_ fin. `fit '!s�/�� ►.�.'� �, �:.,� Iloilo IWARE im lumi WIN � �Ned• �. �� -`�� VIA 9 IV E ��a �� 'fir.■�t�_ �� a orfill � 1 _ /� APPENDIX A. DRAINAGE MAPS • UNINCORPORATED AREAS u afr wen IOn •••�•.•o.ew.ew a 5300EY � G a�x+ 530071 O OTNu AREAS S unoEVEEOrt['oc'o�.srnE eNuuEla('--� CI i 8 710 .r'wi°u new 12 F.e.w....a.,r.. r! � a I I W CRY OF RENPON KING COUNTY I tww. 5300EE` I CRY OF RENTON j -----513----- F'•y"'F' j ` I EL bw�wee m.. 1� D I (1 j { RM7LJI Of RENTON smm •rAT ^.�m`cwe ere s.Nos 9TST'S0".SM?'S0" av, An w.D>n NOTFS A,ow. S I Car w��:�Swew Ema ee p I I j �p 4rwP•tia � w Nana wav ds h U�SAfFT I 11. mw Rapow was o�w lwr+ �a YTw�na�Y - 1C I C�wa�.rt,Oar w aww:s e we�ia�so•d �D. 6 STNEEI I iuw euvs werown c l�w�nw I � RR YF M4P NEPOSTONY T4T SpOr a� j Nw1.b f�1ory lmTwq an NYp IrNe+ MfR S'RffT SENEf1 EFFEC DATE OF i COUNT W.YDE Flom RISOIINaCE NATc NAP / �W CORDORA7f LIMITS x.m.af.nre v EFFECTNE DAms,OF I W"KSI TO�TN-PPN1EE. 3 6T 14 ZONE X NOTE: AREA SHOWN ON THIS►ANSI 1LOCATEDTED xuvwQ C,pwn w��vrse 6 LOCATED WITHIN TOWNSHIP 22 NORTN,RAlY.E 4 EAST AND TOWNSHIP 23 NOUKRANGE 5 EAST CORPORgTE_LIMITS C�GO%jON rfh APPRo%MMTE SCJJ.E IM FFET KING COUNTY UNINCORPORATED AREAS I 530071 =f OF RENTON NATURAL ftm INSURANCE Pmw 7!Ty _ Im FIRM RA O NISUME RATE MAP 5 zowE x KING COUNTY, ZONE AE ZONE x I _ _ — WASHINGTON AND . /t,/ ; A ��r�� — I INCORPORATED AREAS j �� SOUMNES ! n�fT j ►AMEL IN Of 1725 NOT Pa. 1 RM3� 1 • � LONE X � r O � I I CbA11WTY N.II9EA YMFI 4F:Yi lam( CITY OF RENTON 53008E 5 1 I 19 �\ ap)?pqGBROOK CREEK ! g 1 ZONE x / WNTO4 WAST ATM TREATIL%,PUN' E I za Fs MAI NUMBER F oNE zIE O �� O A MAY 16 1l95 AT�•ror f `®� n�2sror ¢2-W=* Tarncr. Fcdu.I F_.S wcy M.p.g—T At-ly AL • �-��.. CITY OF RENTON SURFACE WATER DRAINAGE N SYSTEM „� ..., } M r S 'a .......�: ,=` �o•---, `-��- .::.��-:� LEGEND 1SGS- '.4 •�Isiah } 9S�o�: .6cs�._.,�.2 r': Qr '`- 9 f✓� O j'i � � �`J �•- GIs C+5- _ ' '^ STORM SEWER Ll�S ISGb- -j` CY ^ .� uc6- }sac6-1♦ i �Ft �•''y Iu6-, �SC� — G6=r J i 1SL6-� a .1sH6 n 3ry _ DITCH LINES Coal M ��a Beacon Rine Co Pa CATCH BASKS I� IV MANHOLES Ir y y r` - " Bur(• -- 'n9ton .. .. : ARROWS -- DRECTION 6 - CULVERT CROSSING •;y S�•4 .1 s6 1 `� `..`-._ ,/- ~•�\„ _ -, 16H6-2:.. —— REN 1 ON u H I L/MI S ti. _ (�: :. 16rH6 Swto .. (7 OD ••.. -.. �--.„...xr,..SDI n"Su--set B[ _ 16.H7-9•� - �+ 16H7-9 . -.` -. - 16.37- _ - 16H7-S ,•--•.,j487 3 i6,4;;-Z DISCLAIMER to; -i6H7-1 6,98-3 y; 16H9-s 1689-1 THIS INVENTORY INFORMATION F T STORM DRAINAGESYSTEM mcs-2 - ,y,g-6 - 6 .SIT VAS COMPILED FROM NUMEROUS SOURCES. -...""' '....... ��GB-D 6 IT I IS HE REST INFORMATION AVAILABLE AT THIS T[ -.,. --•-----. ---'-- :-_ _ - ME, AND SHOULD • _. - _� - _.._.,.f .,..1 - - - - - - - . .. BE USED FOR GENERAL GUIDANCE ONLY. THE CITY OF RENTON [9 L41 <1 ...... - IS NOT RESPONSIBLE FOR ERRORS OR OMISSIONS. VHEN THIS Q7 - INFORMATION IS USED FOR ENGINEERING PURPOSES. DESIGNERS •� -"8(l,. ARE TO FIELD VERIFY THIS INFORMATION- n9 f on i 13.L8-li d : -...... y ylwa-1 E9-2 ; } 0 400 800 ISE9-1 1 2orz-6 ti- ��...................�...,,... y ��++y - •-'„""""^-�W:�7 ll'1•.,J..L. - ?aY2-1 14a9-s 16.C9 7 okesdnle Ave f ?�.........,24M2-' _2 .. ::.......................... ._....... e IS r - _„ .... ..... ... . �_, :4 8 0 0 OF > 2� + „a + P/B/PW 'TECHNICAL SERVICES .... ......... 09/23/% - . ..... f 4........ 4324 NE V4 4313 SE 1/4 1