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Home My WebLink AboutSWP272107 L t !` SEC 10, TWP 23 N• RGE 5 E, GYM _ NOTES: A. o t. FOR STOW DRAIN S 3E 9fE£T v. 2. FIXt STORM DRAIN Usutt PR6TIE5 SEE SkTi 1Q ---� x FOR ROAD 1 SIDIW DRAIN N6ftt NOIFS!DETA85 \� •\ \ SEE SHEET 11. I1— BNI.RNFR\ t SEE OETAx 11 MATCMINE - SEE SHEET 6 \ \/ CER 0 ICAL OA ENTON : nm OF RENTW v K ` u.n3D.FS FOB LOTS a 10 i0 *ieu SCu ico oeYM I I t / Tif 1/2XI"EXPANSION tNITERIAL SW(]A.G Y12AGH (M) �Y 1 r \\ S!F/'G� at0.0 I 1 1/t"R AT ANi$ }WSuM ':, RDOF WAM SIIB /1 P Q'M. CWC CINJB Afro QTITEF 50® a I_l��\£. 1IIEIIT mwnw STA 4 j^ / R 4030 �A "" U" t S. a00J FT/FT /igl IBB.Eirel/® sLCRE LINES TO BE RAgAL 2I _ 1 e+ae srr:a: Y sEccvn To'Fm�s+olr iWt. I ro wRe AND d/rrER 1 W uaHtt LOT tt .� >,\ _ a►A0=E®t � i/TXa"EXPANyW MA rEHIAL Ir I EASFIXT 4i0.0 .Y\ q/e5 e� i/s"R AT A➢I15 sGYWE[LYIES I Wr r � I 1 ya Lar Pf 6]YP d•O�ROff �® TYPE 1 WY \\ _ ' , Pr TONE I I rrE DRAM COUM 1x! Sd '"'a. `'�'� \,_:: v _"E i IfE'LV. tO5.5 vM.rt _ p s.:?ot:.. T¢5 ' ��tMW loa.'bOpL1� S i n010 TT/TT {BLit ��'[•X'".': \%'t;:�•::: \.� IAr 3 .1 . J W-moTf OT WDMW I FtQ2M ICI a�>_aa '� �a7 - t 8TY Rfllafl tP er �� k aaR v n x Sz � 01 Y�O�RAM�SIIIB I � RaU _.- _-- �°�•I=` � I satEr RwrE �y� ; t _ mExnan PrE IF I-aRFP sa l�z.ao Y 4wo IOxaa o DRAM ryy'tOSgp IaLN s �» :- e . . I/+•/Fr. aroE r/2 x �1/+ .srnvE q I ,TT Lf{' "AR AL 1/2"R W9 . ' YYY .y P ROti f1aW / RB RENRN ONLY PAVEMENT AS PER PLANS +. PAVEIfENT As PER PLANS S 6'�9� Y - ' r PARKWAY STANDAK)LE% coma T T v" 9M091 MR1tlLKPL,gCE M>' R�Pi Tr y.�� - sTANOAPO CAI. CONG mm AND wlT Y (�- ^-4�-dOIO�>�'�,... -i-,�' 1-q1a,y.C•;' - CURB AND GUTTER 7 . k SU SP .os PL$ E aTUD � SECTION.A-A SECTION 8-B w- :. ' SIDEWALK NOTES: 5! $2Y LT _ .C\'N1S WNMY NON SHALL 6E PLACED NOT TO EXCEED "I" _:[• ' jM{T .� I!I Y- -{O iS LESS NON LESS -IN 10'C/a THEY SHAL NOT I - B£LESS iHAN J/1B"W 1HICKNESS AND SHALL BE RV A' ^I[6 +•.^' .^`-':-. I06 .> - - - 2 I EXTENDED 2-BELOW RIE CUTTER LINE 1/r Ti011/ ROOT Ma II r MUTS SHALL BE PLACED AT ALL COLD. M A5 ' I ME=BY MOVED?AND SHALL EXTEND I"BELOW mB\/t2 MEI B'WEP .\: CONCPETE —_ IETAL LOYTYI __M W I'IFEP I2 W 4-OPEP IF IW.Y3 .•.,.::- ..•.: , W _I _ THE��]j ROLE IMAM�� sIm M a f.T ::' w: r•� . EIZE AM OTTER. .TO B PLA_S BE A COLT 8/ENIOII f I '>. x? meµ I t/y�(5'EIIPANSTW MATFFIAL SHALL BE PLACED FROM I 50®Pn rYPE 1 11 ' —ID� P.aS TO P,T.'S AT ALL WRB RETURNS I/TXI"RN6 BIS! 5FA 12M0 1PII LF 8"6EP ROOF o--•... __ .129 = EXPANSION NATERTAL SHALL BE PLACED AT EVERY (IEAi7B1E�11 f=>:ir LRMI COIII3IOR MAILBOXES FOR � /'� ?7 V THIRD SIDEWALK PANEL. THE CONCRETE MIX FOR SIOEWALYS LIE+BSBB Y•5.a I I 5.aal0 R//T I LOTS 6-11 A 21-23 - SHALL CWIFQW TO THE REOUIREIIENTS OF CUSS B (J/f7 I At, tl '':. TIV �h::: "N —~ MITH AW ENTRAINMENT. mm n T,r�I '[ -; :: Tr aeAR1.ea�EicDo1T - STA 6aSp +yt..:.-...;_'r.�Yc':% v �A�� THE CWOi-1 2HNl HAYS A BROOM FINISH N91H ALL EDOES � I TFR imY. /. ✓} HAWJO A 2-1/P" TOp.ED FINISH. SUWWE COAWAGNW SHALL BE DOS(MODI PROCT(XR) smonl >r amIX" �� BCAB SO } IIaD iT �1 TYPICAL SIDEWALK DETAIL '•I I I I N S FT/}7 fl•3lENr �\ P IE t : N 2 AEI b 7 SCALE' NONE 10'Ururr �' \ Lora ljlj �n+t mow 1� (OAS _ _ 1 I10.0 � 1F E i - Y.CC �• a WT 11 i I2BS I i 4F 60 I / �MOD1MP>TEMORE�fa16H�EP 12' Fr J V. a 'gofC _ I E f02t0 EDn LF• F-% Q y }. L SEE OETAL ♦ J M••a55 fJS OVO31* j J I � 31r M1 I♦�� - .a[Ps •. �..�,�� ` , '-. NE iBFH' TREET �' �'�• i ? •> � .s.='=" END aF NE 81N SiAEET 7'£Y PLAN t PS Ba743! E .. - A:." mE I41zw �1 O� Y TOO - r 1 I BYPASS PW LF IxCFILiRA1KW - .;: - . .. ., LIA .TI O`> I {PPELWE SEE DETAL 8 m7 TYPEI ' If U]211 fjI TYPEL cam sce. EN'D OF ANACORIES eYNau , $ x I 1 1 BTO�LIER 11 S E ILb.00 AWNY StA "7> 58 ` STA 6++5�� I II ' Euv+oLJa �=z.•E CITY OF RENTON E IOa.BO veY yy z Rs-ervi<f recl a-,-o-ts DEPARTMENT OF PUBI-IC WORKS ISSUED FOR RXSIRUCTlW PRC PRC 3-t-BJ tmED FUR cITY wv1Ew PItL 1wc +-ra-BJ MISSION I3I1,L.S SUBDIVISION AD AND STORM N PLAN A I SUED Fa CITY REVIEW WW MC 12 11-02 scALE I 2D' YY ANL BATE ROAD & STORM DRAW UT)UTY PLAN If HARMSEN & ASSOCIATES INC. ^�*'m RRG pA {µt Hp, 1a0.0>-9t o hiN PAPF rh.'i .,� ,�. wl •. wM,tsp PAOP69IDNAL CTYLL zwng RQIO AND LAND 3ORVBYA'G wuWx '' r.a MX sa ».-Yau artaLo se 1'. ZO' IaD w:34$r.n-EZ_ W y - Z 1 O� •` "i�'- �-'--"s/.v : cats mR�M fso m voae IYAp I..T 25 1 A I I I A I A I E I A I 1 I A • NI ' m NOTES �"TT r ry mMARYYOIfdN1111fK. J L—�" 1-.� 4y I i rJ a vrc�v ieuv mu urn �711 err I w ®,a R-r 2 o CITY OF RENTON rwmEaa-a azn v ir4 �- — — rn —— ,.'s LL59fox HILi3 SUB➢fvL4I0N ..��•yy�� .�,�we� r— , Y 'CIlEDAB ANO STORY GRAIN I AU _ ma a m ay. -N^ rwr RPN @ 51[NN CR.IN UIILIlY IW!I I.r•`�1V Z�Q7 �1�• \Q/rue ..a r..'.yuy � •Br1R16d!lk 11^3�pCw r EShortPlatF PL 9REQUEST FOR PROJECT N (PPff To Technical Services Date 5 3 W04 GreemY From: Plan Review/Project Manager /�i r>7e.lc,l� Project Name Mllsslci 1 "ILLS Su@DIVISION3 (70 charace max) Description of Project: WATE;FI S ll,)Me4 SWIM, D"lQ G_ 4- 2oRIJ I.uPROYtr:LI67U}^S FOX t"L uopi N/cts SUBO/V/SIGN LOCq ntril GT /0 .4.y-0 40124Goe76c Circle Size of Waterline: ! 8� 10" 12" Circle One: New or Extension Circle Size of Sewerline: 10" 12" Circle One: ew or Extension Circle Size of Stormline: 12" 15" 18" 24" Circle One: ew or Extension Address or Street Name(s) i((E /0v11 §MM /AAWA9.73M .at/6A/46/ Dvlpr/Contractor/Owner/Cnslt: Aeu6D, /NV S7ucy78/ /VG (70 charactus n=) Check each discipline involved in Project Ltr Drwg 9 of sheets per discipline CY•Trans-Storm CS-cm K_ (Roadway/Drainage) (Offs, t nprovernenuXinclude basin name) (include TESC sheets) Q Transportation (Signalization,Channelizatiou,Lighting) _ T l Wastewater Nouc�i - -- 5 (SakuLazy Sewer Main)(include basin name) la' Water (Mains,valves,Hydrants) t/ (Include composite&Horizontal Ctrl Sheers) _ TS Use Only /Q 7 a�O 46 K71T � - yl - � 1o7 T- a102 w1.c)4p— Approved by TSM _ Date: fonrtslmisct92-090.DOC/CD/bh 1 1 1 1 MISSION HILLS SUBDIVISION 1 RENTON, WASHINGTON FINAL DRAINAGE PLAN 1 1 1 1 s 1 Developer: Allied Investments, Inc. 2817 Horsehead Bay Drive NW d Gig Harbor, AA 98335 1 Contact Person : Gary Senescu (206) 265-6042 1 Engineer. Harmsen &Associates, Inc. 0 17614 - 162nd Street SE Q P. O. Box 516 �b 1 Monroe, WA 98272 Project. Engineer: Perry R. Cole, PE + ' (206) 794-7811 a � , s 1 April 1, 1992 Revised June 25, 1992 t q G ^J 1 HARMSEN & ASSOCIATES, INC Professional Civil Engineering and Land Surveying May 4, 1993 Plan Review Section Development Services Division City of Renton 200 Mill Avenue South Renton, Washington 98055 Attention: Mr. Neil Watts SUBJECT: MISSION HILLS SUBDIVISION PP 169-91 -PLAN REVIEW NO. 2 Dear Neil, Gary Senescu asked me to address the flow capacity of the bypass pipeline that is to be installed on lots 21 and 11. This bypass pipeline is replacing an open channel and a 12" csp pipeline. The open channel is a natural Swale without a constructed centerline or defined side slopes. The 12" csp is currently functioning in a distressed condition, that is the ends have been partially collapsed. The proposed bypass pipeline has a full flow capacity of 2.11 cfs, and a maximum capacity of 227 cfs. The discharge at water surface elevation 404.00 is 1.93 cfs. The water surface elevation corresponding to the 100- year discharge is 403.63. The upstream off-site storm water runoff is shown on page 5 of the FINAL DRAINAGE PLAN, and is summarized below. Sub-basin Return Period Peak Rate Discharge E 2 - year 0.26 cfs E 10- year 0.44 cfs E 100- year 0.66 cfs The flooding experienced by the owner of Lot 8, Honey Dew Estates, Division 3, should be relieved by the installation of the bypass pipeline. The invert elevation of the upstream end of the pipeline is at elevation 403.25 which is 0.75 feet below all but the Southwest corner of Lot 8. Currently the water surface must exceed elevation 404.00 to continue flowing South. Upon completion of the proposed bypass pipeline, it will be discharging approximately 3 times the 100 - year storm inflow when then lot begins to flood. As such the water surface elevation is not expected to rise above 403.63, and the lot is not expected to flood. If you have additional comments and concems that I can address with a phone conversation, please call. My Renton local phone number is 343-5903. 1 appreciate your effort on behalf of the project and I look forward to receiving approval of the construction drawings. Sin Perryl Cole, P.E. Project Manager encl. cc: Gary Senescu f:yabstalliedVmh 11.doo 17614-162nd Street SE'PC Box 516'Monroe,Washington 98272'(206)794-7811 [Fax 743-2737] Circular Channel Analysis & Design Solved with Manning's Equation Open Channel - Uniform flow Worksheet Name: MISSION HILLS Comment: BYPASS PIPELINE - WS EL 404.00 Solve For Actual Discharge Given Input Data: Diameter. . . . . . . . . . 1.00 ft Slope. . . . . . . . . . . . . 0.0030 ft/ft Manning's n. . . . . . . 0.012 Depth. . . . . . . . . . . . . 0.75 ft Computed Results: Discharge. . . . . . . . . 1.93 cfs ICG y04100 Velocity. . . . . . . . . . 3.05 fps Flow Area. . . . . . . . . 0.63 sf Critical Depth. . . . 0.59 ft Critical Slope. . . . 0.0058 ft/ft Percent Full. . . . . . 75.00 8 Full Capacity. . . . . 2.11 cfs QMAX @.94D. . . . . . . . 2.27 cfs -9 - AA ,4Ae Froude Number. . . . . 0.63 (flow is Subcritical) Open Channel Flow Module, Version 3.21 (c) 1990 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Circular Channel Analysis & Design Solved with Manning's Equation Open Channel - Uniform flow Worksheet Name: MISSION HILLS Comment: BYPASS PIPELINE - 100 YEAR INFLOW Solve For Actual Depth Given Input Data: Diameter. . . . . . . . . . 1.00 ft Slope. . . . . . . . . . . . . 0.0030 ft/ft Manning' s n. . . . . . . 0.012 Discharge. . . . . . . . . 0.66 cfs f��fz_,ti/�TyO�✓ ��yg 'L� Computed Results: Depth. . . . . . . . . . . . . 0.38 ft ll Velocity. . . . . . . . . . 2.38 fps Flow Area. . . . . . . . . 0.28 sf Critical Depth. . . . 0.34 ft Critical Slope. . . . 0.0048 ft/ft Percent Full. . . . . . 38.37 % Full Capacity. . . . . 2. 11 cfs QMAx @.94D. . . . . . . . 2.27 cfs Froude Number. . . . . 0.78 (flow is Subcritical) Open Channel Flow Module, Version 3.21 (c) 1990 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 1 MISSION HILLS SUBDIVISION RENTON, WASHINGTON CONCEPTUAL DRAINAGE PLAN 1 ' Developer: Allied Investments, Inc. 9512 State Highway 16 Gig Harbor, WA 98335 tContact Person : Gary Senescu (206) 851-6040 Engineer: Harmsen &Associates, Inc. 17614 - 162nd Street SE ' P. O. Box 516 Monroe, WA 98272 Project Engineer: Perry R. Cole, PE �4 ASf (206) 794-7811 0 a • x April 1, 1992 Revised June 25, 1992 'FCrsrt n� CONTENTS Page ' INTRODUCTION ................................... ..........................................................................................1 TIRWORKSHEET ...............................................................................................................................2 ' PROJECT DESCRIPTION ................................... .............................................................................4 CORE REQUIREMENT# 1: Drainage Discharge at Natural Location ..................................................4 CORE REQUIREMENT#2: Off Site Drainage Analysis ......................................................................5 CORE REQUIREMENT#3: Run Off Control ....................... . ..........................................................7 CORE REQUIREMENT#4: Conveyance System ...............................................................................9 CORE REQUIREMENT#5: Erosion/Sedimentation Control Plan ........................................................9 CORE REQUIREMENT#6: Maintenance and Operation ..................................................................10 CORE REQUIREMENT#7: Bonds and Liability ................................................................................10 SPECIAL REQUIREMENT# 1: Critical Drainage area .......................................................................11 ' SPECIAL REQUIREMENT#2: Existing Master Drainage Plan .........................................................11 SPECIAL REQUIREMENT#3: Master Drainage Plan .......................................................................11 SPECIAL REQUIREMENT#4: Basin/Community Plan .....................................................................11 SPECIAL REQUIREMENT#5: Water Quality Controls .....................................................................11 SPECIAL REQUIREMENT#6: Coalescing Plate Separator ..............................................................11 SPECIAL REQUIREMENT# 7: Closed Depression ...........................................................................12 SPECIAL REQUIREMENT#8: Water Bodies for Run Off Control .....................................................12 ' SPECIAL REQUIREMENT#9: 100 year Flood plain .........................................................................12 SPECIAL REQUIREMENT# 10: Type 1/2 Streams ...........................................................................12 ' SPECIAL REQUIREMENT# 11: Geotechnical Analysis ....................................................................12 SPECIAL REQUIREMENT# 12: Soils Analysis .................................................................................12 ' APPENDIX A Figures...................................................................................................................... APPENDIX B Hydraulic Calculations............................................................................................... APPENDIX C Geotechnical investigation for Storm Water infiltration . ................................................................................ APPENDIX D Need for Regional Detention Facility ........................................................................ ' APPENDIX E Letter concerning downstream conveyance facilities ................................................ HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-140-07-91 Page- 1 ' INTRODUCTION The MISSION HILLS SUBDIVISION DRAINAGE ANALYSIS has been prepared by HARMSEN& ASSOCIATES INC. at the request of Allied Investments Inc. The purpose of the analysis is to satisfy the requirements of the City of Renton's Storm and Surface Water Drainage Ordinance. This report analyses the drainage system for the proposed project with respect to the seven core requirements and twelve special requirements of the King County Surface Water Design Manual and provides recommended measures for meeting those requirements. This report conforms to the requirements for a Level 1 Analysis. The following sources have been relied upon in the preparation of this report and their use is hereby acknowledged. Couvrette Geotechnical Engineering, Data Report: Geotechnical Investigation for Storm Water ' Infiltration, Mission Hills Residential Community, King County, March 31,1992. City of Renton, Comprehensive Plan. City of Renton, Zoning Code and Zoning Map. ' City of Renton, Storm and Surface Water Drainage Ordinance. City of Renton, Sanitary Sewer Plans. City of Renton, Storm Drainage System Maps. City of Renton, Water System Plans. Harmsen &Associates, Inc, Field Notes of Surveys, Field Book 269. King County, Surface Water Design Manual, January, 1990. US Department of Agriculture Soil Conservation Service, Soil Survey ' King County Area, Washington, 1973. US Geological Survey, Renton Quadrangle, 7.5 Minute Series (Topographic), 1949 (photo revised 1968). 1 US Geological Survey, Mercer Island Quadrangle, 7.5 Minute Series (Topographic), 1950 (photo revised 1968). ' In addition to reviewing the resources listed above, informal discussions were held with the Renton School District No. 403 maintenance and facilities staff and the City of Renton Public Works and Planning Department staffs, and a field investigation of the on-site and off-site drainage features was conducted to identify the boundaries of the upstream tributary drainage area, the nature of the surface ' water runoff, flow patterns and conveyance methods. ' 17614-162nd Street SE•PO Bar 516•Monroe,Washington•(206)794-7811 [Fax 7432737] 1 ' Page 1 of 2 King County Building and Land Development Division ' TECHNICAL INFORMATION REPORT (TIR) WORKSHEET !1! Alli d Inv stments,Tor Project Name Mission Hills ' SR 16, NW. Gag Harbor, WA Location ) 851-6040 Township 23N gr Pprry R_ Col _pF Range SE Section 10 Company Harmsen & Assoc. . Inc. ProjectSze 25 lots AC 6 ' Address Phone 17614-162nd st.SE.Monroe.WA Upstream Drainage Basin Size AC 7 - ® Subdivision 0 DOF/G HPA Shoreline Management ' Short Subdivision COE404 0 Rockery C] Grading 0 DOE Dam Safety (] Structural Vaults Commercial 0 FEMA Floodplain Other ' (] Other C^J COE Wetlands HPA 1PAFrrS SITECOMMUNITY . DRAINAGEHASIN Community City of Renton (Proposed annexation) ' Drainage Basin Cedar Ri Ver/L()WPr ('Pllar River Suh—Raci n 't « 7• A ' 0 River 0 Floodplain 0 Stream Wetlands ' 0 Critical Stream Reach 0 Seeps/Springs Depressions/Swales 0 High Groundwater Table Lake Groundwater Recharge ' 0 Steep Slopes Other Lakeside/Erosion Hazard 1 • 1 Soil Type Slopes Erosion Potential Erosive Velocities Al tlorvnnd/Ag r ay Moderate ' Additional Sheets Attatched 1/90 1 Page 2 of 2 ' King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET REFERENCE LIMITATIONISITE CONSTRAINT ' xx Ch.4-Downstream Analysis Level_ 1 Analysis ta 0 a 0 Additional Sheets Attatched ' PARr9, ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS ' DURING CONSTRUCTION FOLLOWING CONSTRUCTION Sedimentation Facilities ® Stabilize Exposed Surface Stabilized Construction Entrance KI Remove and Restore Temporary ESC Facilities ' xx Perimeter Runoff Control ® Clean and Remove All Silt and Debris Clearing and Grading Restrictions Ensure Operation of Permanent Facilities 0 Cover Practices 0 Flag Limits of NGPES ' Construction Sequence 0 Other Other ' PARr1G SURFACE WATERSYSTEM ® Grass Lined Channel = Tank Ej Infiltration Method of Analysis t CE Pipe System © Vault Depression 0 Open Channel Energy Dissapator Flow Dispersal CompensationlMitigation Dry Pond Wetland Waiver of Eliminated Site Storage ' Wet Pond Stream Regional Detention Brief Description of System Operation Collection, Convevance, Biofiltration, Detention, and Infiltration. ' Facility Related Site Limitations Additional Sheets Attatched Reference Facility Umitation ' (May require special structural review)PART11 STRUCTURAL ANALYSIS7 0 Drainage Easement 0 Cast in Place Vault Other Access Easement ' Retaining Wall Native Growth Protection Easement Rockery>4'High Tract Structural on Steep Slope 0 Other SIGNATUREOF PROFESSIONALENGINEER I or a civil engineer under my supervision have visited the site. Actual ' site conditions as observed were incorporated into this worksheet and the altatchments. To the best of my knowledge the information provided �/-/- 92 here is accurate. ' HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-140-07-91 Page- 4 PROJECT DESCRIPTION The proposed Mission Hills subdivision is a 25 lot development on 6.02 acres of land adjacent to Honeydew Estates Divisions 2 and 3, at the intersection of Anacortes Avenue and NE 10th Street. The site is currently in the process of being annexed to the City of Renton from unincorporated King County. The proposed zoning is R-1 and the proposed lot size is 7200 square feet, with an average lot size of 8037 square feet. There will be 24 new single family houses constructed and an existing house on the site will be relocated to one of the new lots. The site will be graded to allow the installation of a gravity sanitary sewer system and the plat road. Water supply will be extended from NE 10th Street for a distance of approximately 1260 feet and will include all associated fittings, valves, hydrants, and thrust blocking. The gravity sanitary sewer extension will consist of approximately 1060 feet of pipe with associated fittings, manholes, and cleanouts. The sanitary sewer from the site will discharge into the ' existing manhole No. 32 in the intersection of NE 10th Street and Anacortes Avenue. Approximately 1045 feet of 32 foot wide roadway with sidewalks, curbs and gutters will be built for the subdivision. ' CORE REQUIREMENT # 1: Drainage Discharge at Natural Location All surface and storm water run off from all pervious and impervious surfaces from the proposed project Will be discharged at the natural location and will not be diverted onto, or away from, the adjacent downstream property. Existing Drainage Features The existing on-site storm drainage features consist of a natural open channel draining south from Lot 7 of the Honey Dew Estates Subdivision No. 3 to a 12 inch CMP culvert under a gravel access road. The discharge from the culvert continues southeasterly in a natural open channel to the southern property boundary. The drainage path continues southeasterly through the eastern third of a wooded field owned by the Renton Church of the Nazarene. There is currently no biofiltration or detention of storm water ' runoff on-site. Proposed Drainage Features ' The proposed storm drainage facilities will collect, detain, and biofiltrate the storm water runoff from the site. Storm water runoff from the roadways will be collected with curb inlets and conveyed in a pipe detention system to the biofiltration swale along the southern boundary of the site. The detention facility ' will provide for staged release at the natural point of discharge. Storm water runoff from the roofs, parking and footing drains of the individual dwelling units will be ' collected and conveyed to the storm drain collection system for detention and release to biofiltration. The proposed drainage facilities will accommodate the existing local drainage patterns as well. The existing discharge onto the site from the Honeydew Estates Division No. 3 and from the adjacent ' unplatted areas will be collected at the north boundary of the site, conveyed in a pipe across the site, and discharged at the existing natural discharge location on the southern property line. t ' 17614-162nd Street SE•PO Box 516.Monroe,Washington.(206)794-7811 [Fax 743-2737] HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-140-07-91 Page - 5 CORE REQUIREMENT # 2: Off Site Drainage Analysis The project site lies just inside the northern boundary of the Cedar River drainage basin. The general ' flow direction is southeasterly. Upstream Tributary Drainage Analysis In general, the runoff from areas north and east of the site is intercepted by the existing storm drainage system within NE 10th Street, Anacortes Avenue NE and Anacortes Court NE and discharges away from ' the site to the north and west. Runoff from the unplatted areas west of the site, except for a portion of the two lots immediately adjacent to the western boundary of the site (fax Lots 159 & 255) discharges by sheet flow in a southerly direction without crossing the site. The runoff from the 0.50 acre area of Tax Lots 159 &255 (sub-basin F), and the 1.60 acre area of Lots 5-10 of Honeydew Estates Div 3 lying south ' and east of Anacortes Court NE (sub-basin E), and the 0.48 acre area of Tax Lot 110 along the northwesterly boundary of the site, as well as the runoff from the 0.70 acre area of three unplatted lots (Tax Lots 228, 299 & 302) (sub-basin D) along the northeasterly boundary of the site, discharges by sheet flow onto the site. The runoff from sub-basin E will be collected in an open channel and conveyed through the bypass pipeline to the natural point of discharge. The runoff from sub-basin F will be collected in a biofiltration Swale and conveyed to the natural point of discharge. The runoff from sub- basin D will be collected in the site drainage facilities, conveyed, detained, biofiltered, and released at the natural point of discharge. The off-site contribution of storm water runoff is summarized below, for calculations see Appendix B, Hydraulic Calculations- Sub-basin Recurrence Peak Q Peakt Interval (cfs) (hours) D 2-year 0.11 8.00 D 10-year 0.20 8.00 D 100-year 0.29 8.00 E 2-year 0.26 8.00 tE 10-year 0.44 8.00 E 100-year 0.66 8.00 ' F 2-year 0.07 8.00 F 10-year 0.13 8.00 F 100-year 0.20 8.00 Downstream Analysis Currently the site drains to a 6.42 acre tract of land consisting of two tax lots (78 and 95)that are owned ' by the Renton Church of the Nazarene. The church development is on the western half of the tract. The eastern half of the property is a wooded field. The storm water runoff discharging from the project site is conveyed in sheet flow and open channels across the wooded field. After a two to three week period ' without rain there was standing water in the wooded field. ' 17614-1 62nd Street SE•PO Box 516•Monroe,Washington.(206)794-7811 [Fax 743-27371 1 1 1 1 HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI#E-140-07-91 Page -6 ' The storm drainage facilities for the church consist of approximately 2.5 acres of roof tops and pavement, and 0.5 acre of landscaping draining to 2 catch basins. The catch basins discharge into a detention pond area. The detention pond area was constructed with an outlet grate and pipe discharging east to the approximately 3 acres of wooded field. There are no provisions for biofiltration in the constructed system. This drainage system has been very poorly maintained and it's utility is, at present, severely compromised. The discharge ends of the pipes from the catch basins have been crushed. The detention pond has been partially filled with construction and landscape debris. The outlet structure has been filled and the grate removed. The discharge end of the outlet pipe has been crushed. During our site inspection of March 24, 1992 there was no evidence that the system could function or had functioned ' in recent history. The church property drains south to the Honey Dew Elementary School site. The school site consists of Tax Lots 121, 7, and 10. The north lot is 3.23 acres, the middle lot is 9.62 acres and the southern lot, ' which is south of and adjacent to the eastern 652.85 feet of the middle lot, is 9.84 acres. The natural drainage course continues southeasterly through the eastern third of the school property. The Renton School District has constructed baseball and soccer fields over the natural drainage course on Tax Lots t 121 and 7 with fill ranging from approximately 3 feet to 4 feet above original grade. A 12 inch concrete bypass pipeline was installed during the original construction. The bypass pipeline has an inlet catch basin, rim elevation 400.00, an intermediate catch basin, rim elevation 401.00, and a discharge catch ' basin with rim elevation 399.00. Invert elevations of the bypass pipeline were not available from the Renton School District maintenance office. The bypass pipeline discharges on the south side of the ball fields into an open channel which continues south and east. We uncovered the inlet to the bypass pipeline during our site inspection on March 24, 1992. It was a standard catch basin frame and grate that was completely covered with leaves, silt and organic debris. It appeared to be infrequently and poorly maintained. We found evidence of an outlet but were unable to actually find an outlet catch basin or pipe end. In its current condition the ballfield fill constitutes a dam which impounds water on the church's ' property. Gary Popovich, Renton School District No. 403 maintenance office, reported that the bypass pipeline ' drains well when it is not plugged but that the neighborhood kids plug the inlet to create a lake to play in. However, from our observation it would appear that the catch basin will plug very readily by itself. Replacing the standard grate with a bar cone top would greatly enhance the function of the inlet. The calculated capacity of the bypass pipeline is 1.81 cfs, see appendix B, "Hydraulic Calculations." ' As designed, the downstream drainage systems convey site runoff via natural open channels, through the church property, and in a bypass pipeline,through the school property,to the continuation of the natural open channel. In its current condition the downstream drainage system has the potential to impound storm water runoff on the church property to a depth of approximately 3 feet, flooding the church's wooded eastern field. Should the impounded water overtop the ballfield embankment, the flow would continue southeasterly across the fields to the original natural channel. The developer, Gary Senescu, has approached the School District with an offer to replace the existing bypass pipeline and inlet/outlet structures with a system that will convey the expected storm water flows ' without back up. The School District has accepted his offer. City Staff is currently reviewing a proposed subdivision called the Orchards, which is directly downstream from the discharge of the School District's bypass pipeline. We have received correspondence, enclosed as APPENDIX E, confirming that the ' conveyance system for that development will accommodate the flows generated from this development and those tributary to it. The proposed construction on the school site will eliminate the problems described in the previous paragraph. ' 17614-162nd Street SE.PO Box 516.Monroe,Washington.(206)794-7811 [Fax 743-27371 ' HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 HAI #E-140-07-91 Page- 7 ' CORE REQUIREMENT # 3: Run Off Control The proposed project will provide surface water runoff control through a combination of peak rate runoff control facilities and biofiltration measures. The proposed storm drainage facilities will collect, detain, and biofiltrate the storm water runoff from the site. The runoff from the adjacent off-site areas that currently flows onto the site will be collected in swales or pipes and bypassed to the natural point of discharge on the southern property line of the site. Storm water runoff from the proposed subdivision roadways will be collected with curb inlets and discharged into the detention facility along the south property line. Runoff from the impervious surfaces at the individual dwelling units will be collected and discharged into the on-site drainage facilities for detention and biofiltration. ' Biofiltration of Runoff The King County Surface Water Design Manual gives specific requirements for water quality treatment of ' surface water runoff based on minimum criteria. Section 1.2.3, Core Requirement#3: "Runoff Control", requires projects proposing more than five thousand square feet of impervious surface subject to vehicular use or storage of chemicals to utilize biofiltration measures prior to discharging off-site. ' Since this project proposes discharging surface runoff from more than five thousand square feet of parking surface, biofiltration will be provided to enhance or maintain water quality prior to discharging off- site. ' The principal mechanism of treatment provided by biofiltration swales is the slowing of runoff so the particles to which pollutants are attached are allowed to settle out. This treatment is also enhanced by the uptake of the dissolved fraction of pollutants by the vegetation lining the Swale. In order to achieve the maximum benefit of biofiltration, the design of the Swale must meet certain geometric criteria. The King County Surface Water Design Manual recommends a trapezoidal shaped Swale with 3:1 side slopes and a length of 200 lineal feet, or the equivalent water surface area, with a design flow rate equal to the ' 2-year 24-hour duration design storm event. Additional design criteria for the design of biofiltration swales and filter strips were presented by Richard Homer, Ph.D., at the October 17, 1991 University of Washington, College of Engineering seminar, "Biofiltration for Storm water Runoff Quality Enhancement." These criteria addressed design for residence time and cross section stability. Storm water runoff from the roadways in this project will be collected with curb inlets, detained in a pipe system, and discharged into a biofiltration Swale along the site's southern boundary. The biofiltration ' Swale will be constructed according to the parameters set forth by the King County Surface Water Design Manual and the recommendations presented by Richard Homer. With the use of this method for water quality control, the surface runoff from this site will be improved and subsequently have no adverse ' impact on the surrounding area. Design of the Detention Facility ' In addition to runoff control, detention facilities which are well designed will provide for valuable water quality enhancement to the surface water runoff. By restricting the release of the smaller, more frequent storms, the detention system promotes gravity sedimentation and becomes particularly effective in the removal of pollutants that are common in urban storm water. ' 1 761 4-162nd Street SE.PO Box 516.Monroe,Washington.(206)794-7811 [Fax 743-2737i ' HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-140-07-91 Page- 8 ' The City of Renton Drainage regulations provide for designing the detention facility according to the King County Surface Water Design Manual. ' Hydrologic Analysis Using the Santa Barbara Unit Hydrograph Method and the King County Surface Water Management Division's HYDROGRAPH computer program routines, runoff hydrographs for the Proposed Mission Hills Subdivision site were calculated for the 2-, 10-, and 100-year, 24 hour, storm events for both existing and developed conditions. ' The existing site consists of two drainage sub-basins. The first is the site proper with 5.7 acres of pervious area, CN=85, and 0.3 acres of impervious area with CN=98 and the second is sub-basin D, from the off-site analysis, with 0.4 acres of pervious, CN=86, and 0.3 acres of impervious, CN=98. ' The developed site has three sub-basins. Sub-basin A has 1.0 acres of pervious area, CN=86, and 0.2 acres of impervious area, CN=98, for a total of 12 acres. Sub-basin B is the plat road with 0.22 acres of previous area, CN=0.86, and 1.38 acres of impervious area, CN=98. Sub-basin C is 3.2 acres with 1.6 ' acres pervious, CN=86, and 1.6 acres impervious, CN=98. SITE HYDROLOGIC CHARACTERISTICS Recurrence Precipitation Q Exist t Exist Q Dev. t Dev ' Interval (inch) (cfs) (hours) (cfs) (hours) 2-year 2.0 0.54 8.00 1.35 7.83 ' 10-year 2.9 1.10 8.00 2.19 7.83 100-year 3.9 1.64 8.00 3.16 7.83 In an iterative process, using the King County Surface Water Management Division's HYDROGRAPH computer program routines, various designs were tested for the detention facility and flow control device. The resulting solution selected forthe design provides for approximately 12,535 cubic feet of storage ' volume in 1000 feet of 48"-diameter culvert pipe (or its equivalent) with staged release of the discharged runoff, as described below, through multiple orifices. Due to site constraints a 57"x 38" corrugated steel pipe arch was selected as the detention tank. Bottom orifice: 3.04"-diam. Middle orifice 5.04" diam. Top orifice: 2.27"-diam. Performance Inflow Target Actual Storage Curve (cfs) Outflow Outflow Volume ' (cfs) (cfs) (cf) 2-year storm 1.35 0.54 0.55 6240 10-year stone 2.19 1.10 1.02 8980 100-year stone 3.16 1.64 1.64 12535 ' 17614-162nd Street SE•PO Box 516.Monroe,Washington•(206)794-7811 [Fax 743-2737] HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 HAI #E-140-07-91 Page- 9 CORE REQUIREMENT # 4: Conveyance System The storm drainage system will be designed to convey the peak rate runoff from the 100-year storm originating on-site and the off-site contribution through the project site. As previously mentioned, sub- basins E and F, off-site, will be conveyed through the site in a bypass pipeline and biofiltration Swale, respectively. Sub-basin B. the subdivision road, will be collected and piped to the detention tank. The detention tank has been designed to accommodate the 100-year peak rate runoff. The biofiltration swales will be designed to treat the water quality stone and to be stable during the 100-year peak rate runoff. ' CORE REQUIREMENT # 5: Erosion/Sedimentation Control Plan ' All sedimentation/erosion facilities must be in operation prior to site clearing and building construction, and they must be satisfactorily maintained until all construction is completed and the potential for on-site erosion has passed. Individual lot infiltration systems will not be connected to until the house construction is complete and the lot stabilized. Temporary sedimentation and detention facilities will be ' provided on each lot during construction. These measures shall conform to the requirements of the City of Renton and include the following. Erosion/Sedimentation Control Provisions 1). Before any construction or development activity occurs, a pre-construction meeting must be held with the City of Renton Department of Public Works, Design Engineer. 2). A clearing control fence shall be installed prior to construction at the boundaries of clearing limits shown on the plats. No disturbance or removal of any ground cover beyond the clearing limits shall be allowed. 3). All areas stripped of vegetation, where no further work is anticipated for 15 days, shall be immediately protected with approved ESC methods. Grass seed may be applied by hydroseeding. The grass seed mixture shall be approved by the City of Renton. 4). Stabilized construction entrances and wash pads shall be installed prior to construction and maintained throughout the duration of the project. ' 5). Off-site streets must be kept clean at all times. 6). All catch basins collecting water from the site shall have their grates covered with filter fabric during construction. 7), At no time shall more than one foot of sediment be permitted to accumulate in catch basin sumps prior to removal. 8). Whenever possible, natural vegetation will be maintained for silt control. 9). A filter fabric fence shall be constructed on the downhill boundaries of all disturbed areas to ' intercept sheet runoff from the site during construction. 10). Washed gravel backfill adjacent to Filter Fabric Fences shall be replaced and the filter fabric cleaned or replaced if made non-operational by silt. ' 11). Interceptor swales shall be cleaned when silt accumulation exceeds one-quarter depth. Pollution Control Provisions ' No significant pollution, either in amount or nature, will be generated by the proposed development of this property. ' 17614.162nd Street SE.PO Box 516.Monroe,Washington.(206)794-7811 [Fax 743-2737] ' HARMSEN&ASSOCIATES,INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI#E-140-07-91 Page - 10 t 1). Oil drippings from automobiles using the streets and driveways will be washed into the catch basins. The design of the catch basins with submerged outlets will separate oil and grit by gravity. 2). Periodical cleaning will be required to remove sediment from the catch basin sumps and floating ' oil and scum from the water surface. 3). Solid waste construction debris will be removed regularly from the site. 4). Construction chemicals (paints, paint thinners, solvents, fuel and lubricating oils, soil sterilizers, ' pesticides, etc.) shall be handled as toxic wastes and shall be disposed by a DOE approved method. ' CORE REQUIREMENT# 6: Maintenance and Operation The plat of Mission Hills will be designed and constructed to meet all requirements of the Renton Storm and Surface Water Drainage Ordinance. The collection, conveyance, biofiltration, infiltration, and detention facilities will be regularly inspected and maintained in good working order. After the first year of operation it will be requested of the Public Works Department of the City of Renton that an inspection be performed and that the Department approve the drainage facilities. At that time the required surety bond will be extended for one year to cover the City's first year of maintenance. The plat map will be prepared and recorded which conveys all easements necessary for maintenance of the storm drainage system to the City of Renton. ' At the end of a three year maintenance period the Plat of Mission Hills will request that the Public Works Director recommend, and that the City Council concur with the recommendation, that the City of Renton assume the maintenance of the storm drainage facilities, in accordance with Section 4-22-13 of the City Code. ' CORE REQUIREMENT# 7: Bonds and Liability The Plat of Mission Hills will post with the Director of the Department of Public Works surety and cash bonds or certified check for the construction of the storm water facilities. The following bonds will be posted: Construction Bond, covering the cost of conforming said construction to the approved drainage plans; and Maintenance Bond, a three year bond posted upon release of the Construction Bond. The Plat of Mission Hills will also maintain a liability insurance policy during the private ownership of the ' storm water drainage facilities which names the City of Renton as an additional insured, without cost to the City. All bonding and insurance will be in accordance with the requirements of Section 4-22-12 of the City Code. t 17614-162nd Street SE.PO Box 516.Monroe,Washington.(206)794-7811 [Fax 743.27371 HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 HAI #E-140-07-91 Page- 11 ' SPECIAL REQUIREMENT # 1: Critical Drainage Area This Special Requirement does not apply. ' SPECIAL REQUIREMENT # 2: Existing Master Drainage Plan tThis Special Requirement does not apply. ' SPECIAL REQUIREMENT # 3: Master Drainage Plan This Special Requirement does not apply. ' SPECIAL REQUIREMENT # 4: Basin/Community Plan ' This Special Requirement does not apply. SPECIAL REQUIREMENT # 5: Special Water Quality Controls The proposed Mission Hills subdivision does not meet the threshold requirements for this Special Requirement. The subdivision will construct more than 1 acre of impervious area which will be subject to ' vehicular traffic but does not discharge to a regional facility, receiving water, wetland or closed depression without on-site peak rate runoff control. The project also does not discharge to a Type 1 or 2 stream or Type 1 wetland within 1 mile from the project site. Although not required by the threshold requirements for a Water Quality Swale, the City of Renton requires biofiltration for projects creating ' more than 5000 square feet of impervious area subject to vehicular use. The discussion of the biofiltration Swale can be found in Core Requirement# 1, Proposed Drainage Features, and Core Requirement#3, Biofiltration of Runoff. ' The downstream analysis, Core Requirement#2, identified deficiencies in the downstream facilities that create a potential for a constructed closed depression condition. In recent discussions with City Staff it ' was determined that the replacement of the bypass pipeline at the Renton School District's Honey Dew Elementary School would eliminate the constructed closed depression condition. Correspondence with Mr. Edgar T. Jones, PE of DODDS ENGINEERS, INC. confirms that the Orchards Development, adjacent and downstream from the school, has sized conveyance facilities to accommodate the storm ' water discharge from the Mission Hills subdivision and it's off-site tributary areas. Additionally we have identified the opportunity for the City of Renton to investigate the creation of a regional detention facility to help eliminate the recurring flooding that the area experiences. A separate letter to Mr. Tom Kress, ' PE has been included in Appendix D. SPECIAL REQUIREMENT # 6: Coalescing Plate Separator This Special Requirement does not apply. t 17614-162nd Street SE.PO Box 516•Monroe,Washington•(206)794-7811 [Fax 743-27371 HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 26, 1992 HAI #E-140-07-91 Page - 12 SPECIAL REQUIREMENT # 7: Closed Depression The existing embankment and bypass pipeline at the Honey Dew Elementary School obstructs the natural flow path thus creating a potential closed depression condition downstream from this project. We have prepared a design and have received approval from the School District to replace the existing bypass pipeline with a new pipeline as part of the School's maintenance program. The pipeline is designed to convey the storm water flows and minimize maintenance problems. Additionally we have received notification stating that the property being developed immediately downstream from the discharge of the bypass pipeline, the Orchards Development, has been designed to receive the flows from the Mission Hills Subdivision project. This maintenance eliminates the potential for a closed depression condition, therefore this Special Requirement does not apply. SPECIAL REQUIREMENT # 8: Water Bodies for Run Off Control This Special Requirement does not apply. SPECIAL REQUIREMENT # 9: 100 year Flood plain This Special Requirement does not apply. SPECIAL REQUIREMENT # 10: Type 1/2 Streams This Special Requirement does not apply. SPECIAL REQUIREMENT # 11: Geotechnical Analysis This Special Requirement does not apply. SPECIAL REQUIREMENT # 12: Soils Analysis The discussion of soil conditions in this report is informed by data contained within the Soil Conservation Service (SCS) Soil Survey of King County- 1973. According to the SCS, the project site is underlain by the Alderwood (AgC) series of soils. For specific technical information regarding the soils on the project site, please refer to the Couvrette Geotechnical Engineering Data Report Geotechnical Investigation for Storm Water Infiltration, Mission Hills Residential Development, dated March 31, 1992, which is included in Appendix C hereto. The proposed Mission Hills subdivision is in Zone 2 of the City of Renton's Aquifer, which is a designated ground water recharge area. The initial storm drainage system proposed in December of 1991 was an infiltration system designed to provide collection, biofiltration, and infiltration of the storm water runoff. The design was based on information provided by the U S Department of Agriculture, Soil Conservation Service. A site investigation was performed by Couvrette Geotechnical Engineering to verify the design parameters for the infiltration system. The results of the infiltration tests indicated that an infiltration system is not feasible for this site. 1 17614-162nd Street SE•PO Box 516•Monr ,Washington.(206)794.7811 [Fax 743-27371 ' HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-140-07-91 1 APPENDIX A-FIGURES 1 ' Figure 1 - DRAWING 3- CONCEPTUAL STORM DRAINAGE PLAN Figure 2 - DRAINAGE SUB-BASINS ' Figure 3 - DOWNSTREAM ANALYSIS 1 1 1 1 ' 17614-162nd Street SE•PO Box 516.Monroe,Washington•(206)794-7811 [Fax 743-2737] �mYaw .m..$� STORM WATER ORAINACF NOTES: p m� — — _ 0 ooi[.rv+im e..[aur.wo x..oxw IT v.. um aw I I I I � _.• ry RENSIDN� ♦ a, Ys mme,[n,m.m..<m°„ aaCa y � ' ! :. ram.[ B .roo�n��.'""mvr-i mim-m.�.cw�a'�.vu[•m e mn.m. •swam mM[. ..�W p _ avw.v.nw n. rr ♦ Mai im[pi[��Kmi�V ? M.♦ a ' ` a ♦ A §a[ � n b ! �� "O1 e[ow.aawrv°`oun°p"GN°� O 2 Q OY w w m�.mwoew¢am roriu'�01n i[� z<¢ 2 , a �TORM ORAINA E PLANORAINA E PLAN O 3 ' Figure 2 - DRAINAGE SUB-BASINS Z l5 70 7C 6 ,,,��,,, rvr4,s 15 c 6 �• 10 1 iuo 16b A. Nev z - 2.25 saos 18 I7 16 14 1.3 r iZ Q 1 ,�- Yp 70 65 rn ' 80 328. n D N.E. 10TH ST- la 81 11 100 bib v05 z 198.93 f {t o n — �t2 ' SO 10%us v — U 0.21 A 14 0.41 A<. s' >aza 0 NE E o 6 �.1 ' �0,23 4 ' ANACO Mike S iler A Ilia Ac. 35 Ac .1z �•� Ac. EST ESQ IV. Q. 3 W 100. rnIcr •A• g 71 5 . 6 a 7411 2 . rlao B3 DS G .i� 4. 7 0.99Ac. �� n O � R. Cumber 316.71 as e gP^ QAA C. t�si sz 42 Ac. a ph R. Newton law 1.32 Ac. q �Z 316.38 14 100 RENT ON 127 C PORATE LIMIT Fred Alberts et ux . 2.54 AC. 1278.19 - 95— Fred Alberts et ux 3.48 AC. m I78 1278.85 School District 403 3.23 Ac. Antonio 12TZ32 ✓1 4.9= 61 L' 15- 4 A. Nev � --3 Figure 3 - DOWNSTREAM ANALYSIS ^`"® Ne 11 ' 10 (� N.E. JOTH ST ro xn c+I nx lse.51 .2SAc. \I ni �, c, 0.21 015 2 j Ac 0.41Ac. I N E �,75 0.23 4t aAN�CO Mike S ilea j; Ac. . 6 P .35A N ICZ IN sts*. = 8 -1Im l 0.21 EST 1 ^ S LIV 0. 3,.... •.• k �n s x 7 z . r . !a R4-,0`AC.10.99Ac. e s /z4.7r R. Cumber 116t{ �u 0.42 A 1 f 1"' .3s Ralph R. Newton -= 0.46Ac. 1.32 Ac. 1 I s 4 kb9_I 116.38 ,00 i4 7' RENTON 1 � e � Fred Alberts et ux . ( 2.94 AC. e Fred A ert5 et ux � .46 Ac. drool District 403 5.23 Ac Antonio 127 . •{' I 1 1 1 HOE Et A91 s w A it G O 3 iPi?c School Oii5 t'ct 403 9.62 AC m �• I 111 / I �s� s� � � 1 � x+n2r^cc— ,r �F— :v�+i+..,.. }2757 �.e .�.: -�-=•e. -�. ..er-r '116 .9E iIlpNf ®TH ISO 0.32 Ac 1\� �-� t ` 0.25 6 A 2 $r 0.26AE 1 I I 600.25 Ac 0.'1'IWs $ 14. \,`I i.✓i9ri � A2s UlAc. 030Ac. �� :O.dlAc^ \\\ ' S6 52� 14 o.Li 10 176 D3 1So Is `% - e . School D.i;trlct 403 '9.84 Ac. - N t • Sr. 4.68AG William J. Bonds. ' HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 ' HAI #E-14D-07-91 APPENDIX B - HYDRAULIC CALCULATIONS 1 ' SBUH Hydrographs Detention Facility Sizing ' Downstream Hydraulics 17614-162nd Street SE•PO Box 516•Monroe,Washington•(206)794-7811 [Fax 743-27371 1 S .C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES ) ' 2, 24 ,2 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******* ** *****ssss 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV ) , CN( IMPERV) , TC FOR BASIN NO. 1 5. 7,85 ,0. 3 , 98, 92 .5 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN W �• 6. 0 5 . 7 85 .0 . 3 98. 0 92. 5 ' PEAK-Q(CFS) T-PEAK(HRS ) VOL(CU-FT) . 43 8. 50 18174 ' ENTER [d: ] [path] filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: J :\site2ex Si TTz F'x �si-7'i✓G Q z 1 1 1 1 1 1 1 1 ' n.unv.rnnrn i . rarfn-q•- . ai ura 1-rnAa= 0. 11 nmo 11= u rillNuir.a HYDROGRAPH 2 : PEAK-Q= .20 CFS T-PEAK= 8.00 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= 1 . 10 CFS T-PEAK= 8 .00 HRS TOTAL VOLUME: 38616CU-FT SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \sitel0ex 15"� ��S��riJ ' ENTER: TRAVEL TIME ( MINUTES) OF HYDROGRAPH 1 0 ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 2 c:\d100 1 ENTER: TRAVEL TIME (MINUTES ) OF HYDROGRAPH 2 0 ' DATA PRINT-OUT: HYDROGRAPH 1 : PEAK-Q= 1 . 36 CFS T-PEAK= 8. 17 HRS TT= 0 MINUTES ' HYDROGRAPH 2: PEAK-Q= .29 CFS T-PEAK= 7.83 HRS TT= 0 MINUTES HYDROGRAPH SUM: PEAK-Q= 1 . 64 CFS T-PEAK= 8.00 HRS ' TOTAL VOLUME: 55698CU-FT SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \sitel00ex c: \d100 ENTER: TRAVEL TIME (MINUTES ) OF HYDROGRAPH 2 0 DATA PRINT-OUT: ' HYDROGRAPH 1 : PEAK-Q= 1 . 36 CFS T-PEAK= 8. 17 HRS TT= 0 MINUTES HYDROGRAPH 2 : PEAK-Q= .29 CFS T-PEAK= 7 .83 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= 1 . 64 CFS T-PEAK= 8.00 HRS TOTAL VOLUME: 55698CU-FT ' SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\sitel00ex FILE ALREADY EXIST; OVERWRITE (Y or N) ? 1 p SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP s DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN n 6.0 5. 7 85 .0 .3 98.0 92. 5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) .91 8. 17 33560 1 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c :\sitel0ex 5�� ' ��"X�sTli'✓G Q i r7 ' c: \sitel0ex SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP ' n STORM OPTIONS: ' 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE ' SPECIFY STORM OPTION: 1 t S.C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 100, 24, 3 .9 ' ---------------------------------------------------------------------- ******************** S.C. S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3. 90" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 5. 7,85 ,0, 3 ,98, 92. 5 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 100,24 ,3. 9 ---------------------------------------------------------------------- ' ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3 .90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 5 . 7,85 ,0, 3, 98,92 .5 DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN W/ 5 . 7 5 . 7 85 .0 .0 3.0 98 .0 / J �✓ PEAK-Q(CFS ) T-PEAK(HRS) VOL(CU-FT) ' 1 .36 8. 17 48266 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\sitel00ex ' S/Z;5 'e'X/s/7i✓G C::� /©0 ' SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP c ' ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 3 c:\c100dev ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 3 0 DATA PRINT-OUT: ' HYDROGRAPH S: PEAK-Q= 1 .84 CFS T-PEAK= 7. 83 HRS TT= 0 MINUTES HYDROGRAPH 3 : PEAK-Q= 1 . 34 CFS T-PEAK= 8.00 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= 3. 16 CFS T-PEAK= 7.83 HRS W/o �J TOTAL VOLUME: 66971CU-FT SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\sitel00dev IV O .VV YOJO ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\f100 ' c:\f100 SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: ' 1 - S.C.S. TYPE-IA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE ' SPECIFY STORM OPTION: 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 2 , 24 ,2 ----------------=----------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2. 00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 1 .0,86,0.2, 98, 57. 4 ' 1 S.C.S. TYPE-IA RAINFALL DISTRIBUTION ' ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 2,24,2 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 1 . 0,86, 0. 2, 98 , 57.4 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN 1 .2 1 .0 86. 0 . 2 98.0 57.4 ' PEAK-Q(CFS) T-PEAK(HRS ) VOL(CU-FT) . 14 8.00 4330 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \a2dev 1 ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 1 .0 ,86 ,0 .2 ,98, 57.4 DATA PRINT-OUT: AREA(ACRES ) PERVIOUS IMPERVIOUS TC(MINUTES ) I N li1V N tiv 1 .2 1 .0 86 .0 .2 98.0 57 .4 ' PEAK-Q(CFS) T-PEAK(HRS ) VOL(CU-FT) . 14 8.00 4330 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c :\a2dev FILE ALREADY EXIST; OVERWRITE (Y or N) ? Y SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 0 .22 ,86, 1 .38, 98, 5 .5 t . 14 8.00 4330 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: ' c:\a2dev FILE ALREADY EXIST; OVERWRITE (Y or N) ? 9 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 0. 22,86, 1 .38 ,98 ,5. 5 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN ' 1 . 6 . 2 86 .0 1 .4 98 .0 5. 5 PEAK-Q(CFS ) T-PEAK(HRS) VOL(CU-FT) . 73 7.67 9566 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \b2dev SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 2 0.22 ,86 , 1 . 38, 98, 5 . 5 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 .6 .2 86 . 0 1 .4 98.0 5 . 5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 73 7.67 9566 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\b2dev SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP ' ---------------------------------------------------------------------- carman. n /nVnlr% n.,i nvmry . irv..vnv% "II T........... ...... ...... -.-. .._. .. 1 L S .C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ( YEAR) , DURATION(HOUR) , PRECIP(INCHES) 2-24----------------------------------------------------------------- - ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ----------------------------------------------------- ENTER A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 ' 1 .6,85.0,98,92.5 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 .6 1 .6 85.0 .0 98.0 92.5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 10 8.50 4563 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH : c: \b2ex ' 1 S .C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10,24,2.9 ----------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2.90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A( PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 1 .6.85,0,98,92.5 DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 .6 1 .6 85.0 .0 98.0 92.5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) .23 8. 17 8625 t ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH : . c:\blOex tSd5-6i9s..✓ �3 - x �s�-7i 1 ' 1 S.C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ( YEAR ) , DURATION(HOUR) , PRECIP(INCHES) ' 100_24-3-9------------------------------------------------------------ ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3.90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A( PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 ' 1 .6.85, 0,98,92.5 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 .6 1 .6 85.0 .0 98.0 92. 5 PEAK-Q(.CFS) T-PEAK(HRS) VOL(CU-FT) .39 8. 17 13554 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH : c:\.b100ex 1 ui.♦cn. of%rnnv I , Vn krznv I , Hl 1PlY6Mv ) , l./vl 1P1Y6MV ) , '1'U NUM 15ab114 NU. J 1 .6 ,86, 1 .6, 98,60 .4 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' . 73 7.67 9566 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\b2dev ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 3 1 . 6,86, 1 .6, 98,60.4 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN ' 3 .2 1 . 6 86 .0 1 .6 98.0 60.4 PEAK-Q(CFS ) T-PEAK(HRS) VOL(CU-FT) t .55 8.00 15055 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c :\c2dev c :\c2dev t SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM ' 3 - STORM DATA FILE SPECIFY STORM OPTION: tS.C.S.S TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 10,24, 2 .9 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2. 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 ' 1 .0,86,0 .2, 98 ,57. 4 1 ' S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10, 24 ,2. 9 ------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2 .90" TOTAL PRECIP. ********* ------------------------- ------------------------------------------ ' zalmn; nkraav ) , v.n�ranvj , nktMrntcv / , l'1V� LMYCIYYf , i� rvn tsN.a uv rv�. i 1 . 0,86 ,0 .2, 98, 57 .4 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) ' A CN A CN 1 . 2 1 .0 86 .0 .2 98 .0 57.4 PEAK-Q(CFS) T-PEAK(HRS ) VOL(CU-FT) ' . 28 8.00 7588 ENTER [d: ] [path] filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: ' c : \alOdev . 28 8 . 00 7588 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c :\alOdev ' FILE ALREADY EXIST; OVERWRITE (Y or N) ? Y SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 0 .22,86 , 1.38, 98, 5. 5 ' DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 .6 . 2 86. 0 1 .4 98.0 5.5 ' PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) 1 . 10 7.67 14627 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \blOdev ENTER [d: ] [path] filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\blOdev . ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP 1 .6, 86, 1 . 6,98 , 60.4 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 3 ' 1 .6, 86, 1 . 6 ,98 ,60.4 DATA PRINT-OUT: t AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 3 .2 1 . 6 86.0 1 .6 98.0 60.4 ' PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 92 8.00 24383 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: clOdev 1 ' S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 100 ,24 , 3 . 9 ' ---------------------------------------------------------------------- ******************** S.C.S. TYPE-IA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3.90" TOTAL PRECIP. ********* ' ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 1 . 0,86, 0.2, 98, 57. 4 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN 1 .2 1 .0 86. 0 .2 98.0 57.4 ' PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) .44 8 .00 11450 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: tc:\a100dev ' .44 8.00 11450 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \al00dev ' FILE ALREADY EXIST; OVERWRITE (Y or N) ? s410 -,6rh y Qom ✓ q /00 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c 1. ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 2 0.22 ,86, 1 . 38, 98, 5. 5 DATA PRINT-OUT: AREA(ACRES ) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN 1 .6 .2 86. 0 1 .4 98. 0 5 .5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) 1 . 53 7 .67 20322 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \b100dev � _ -f�/ J /�/ ENTER [d: ] [path] filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\b100dev ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP c ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 3 1 . 6,86, 1 .6, 98,60.4 t DATA PRINT-OUT: T,rTTT•,Tn'*n mM1"`T,."m^^ , e nr!s I � nc l nv.nvrnrts. ' HnGn\e11�[LbJI C8nv1VVJ Imr nv1VV.7 It,�fi1N UIGJ! A CN A ON 3 .2 1 .6 86. 0 1 .6 98.0 60.4 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' 1 . 34 8. 00 35168 ' ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \c100dev ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 1 c: \a2dev ' ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 1 5. 5 ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 2 c:\b2dev ENTER: TRAVEL TIME (MINUTES ) OF HYDROGRAPH 2 ' D DATA PRINT-OUT: ' HYDROGRAPH 1 : PEAR-Q= . 14 CFS T-PEAK= 8.00 HRS TT= 5 MINUTES HYDROGRAPH 2: PEAK-Q= . 73 CFS T-PEAK= 7 .67 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= .82 CFS T-PEAK= 7 .67 HRS TOTAL VOLUME: 13764CU-FT ' SP_ECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT , S - STOP c HYDROGRAPH SUM: PEAK-Q= .82 CFS T-PEAK= 7. 67 HRS TOTAL VOLUME: 13764CU-FT SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP c ENTER: [d: ] [patb]filename[ .ext] OF HYDROGRAPH 3 c:\c2dev ' ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 3 0 DATA PRINT-OUT: tHYDROGRAPH S: PEAK-Q= .82 CFS T-PEAK= 7. 67 HRS TT= 0 MINUTES HYDROGRAPH 3: PEAK-Q= . 55 CFS T-PEAK= 8 .00 HRS TT= 0 MINUTES tHYDROGRAPH SUM: PEAK-Q= 1 . 35 CFS T-PEAK= 7.83 HRS TOTAL VOLUME: 28752CU-FT ' SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 1 c: \alOdev ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 1 5. 5 ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 2 c:\bl0dev ' ENTER: TRAVEL TIME (MINUTES ) OF HYDROGRAPH 2 0 DATA PRINT-OUT: HYDROGRAPH 1 : PEAK-Q= . 28 CFS T-PEAK= 8. 17 HRS TT= 5 MINUTES HYDROGRAPH 2 : PEAK-Q= 1 . 10 CFS T-PEAK= 7 .67 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= 1 . 29 CFS T-PEAK= 7.83 HRS TOTAL VOLUME: 22134CU-FT ' SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP c HYDROGRAPH SUM: PEAK-Q= 1 .29 CFS T-PEAK= 7 . 83 HRS ' TOTAL VOLUME: 22134CU-FT SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP c ' ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 3 c :\clOdev ' ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 3 0 ' DATA PRINT-OUT: HYDROGRAPH S: PEAK-Q= 1 .29 CFS T-PEAK= 7.83 HRS TT= 0 MINUTES HYDROGRAPH 3: PEAK-Q= . 92 CFS T-PEAK= 8 .00 HRS TT= 0 MINUTES ' HYDROGRAPH SUM: PEAK-Q= 2. 19 CFS T-PEAK= 7 .83 HRS ' TOTAL VOLUME: 46589CU-FT iQ,.r v �J9 (� SPECIFY: C - CONTINUE, N - NEWJOB, F - FILE, P - PRINT, S - STOP f 1 ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 1 tc:\alOOdev ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 1 ' 5 . 5 ENTER: [d: ] [path]filename[ .ext] OF HYDROGRAPH 2 c:\bl00dev ' ENTER: TRAVEL TIME (MINUTES) OF HYDROGRAPH 2 0 ' DATA PRINT-OUT: ' U : \slLeivvex SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP STORM OPTIONS: 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE ' SPECIFY STORM OPTION: 1 ' S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 2 ,24,2 ---------------------------------------------------------------------- ' ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2 .00" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 0 . 4, 86, 0. 3 , 98 ,57.4 ' ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 2 ,24 ,2 ---------------------------------------------------------------------- ' ******************** S.C.S. TYPE-IA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2 .00" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0. 4,86, 0.3 ,98 ,57.4 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) ' A CN A CN . 7 .4 86. 0 . 3 98.0 57 .4 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' . 11 8. 00 3130 ENTER (d: ] [path] filename( .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: t c: \d2 SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' c: \d2 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: 1 - S.C.S. TYPE-IA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE SPECIFY STORM OPTION: ' 1 .. I m.,,,,- , . .,. ..,,,.. . ' O.U.a. llrr.-lea RM ArMLL L1J1n1DV11 Vlv ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 10, 24,2 . 9 ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2. 90" TOTAL PRECIP. ********* ' --ENTER:----------A(PERV)---,--------CN(PERV)--,--A(IMPERV)---------,---------CN(IMPERV)---,--TC----FOR---BASIN-------N0.---1--- 0.4 ,86 ,0. 3 , 98,57.4 ' 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10,24,2 . 9 ---------------------------------------------------------------------- ' ******************** S.C.S. TYPE-IA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2 .90" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0.4,86,0. 3 , 98, 57. 4 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) ' A CN A CN . 7 .4 86.0 . 3 98.0 57 .4 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' . 20 8.00 5142 ENTER [d: ] [Path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\d10 c: \dl0 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: 1 - S.C.S. TYPE-lA ' 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE SPECIFY STORM OPTION: ' 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) ' 100 ,24,3 . 9 ---------- S.C. S. TYPE-lA DISTRIBUTION ******************** 100-YEAR 24-HOUR STORM **** 3. 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 ' 0.4,86,0.3,98, 57 .4 ' A.U:a. 1TCE-IA NAINVALL 1J1011louilvN ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 100 ,24 ,3.9 ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3 .90" TOTAL PRECIP. ********* ' --ENTER:------A(PERV)-------,---CN(PERV)-------,--A( IMPERV)---------,---CN(-------IMPERV)--,--TC---F-OR---BASIN------NO.-----1-- 0. 4,86,0.3 , 98,57.4 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN . 7 .4 86.0 . 3 98. 0 57 .4 PEAK-Q(CFS ) T-PEAK(HRS) VOL(CU-FT) . 29 8.00 7468 ENTER [d: ] [Path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\d100 ' c :\d100 SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n STORM OPTIONS: 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE SPECIFY STORM OPTION: 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ' ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 2 , 24,2 ---------------------------------------------------------------------- ******************** S.C. S. TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0. 9,86,0. 7,98, 58.8 ' 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ' ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 2 , 24,2 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 ' 0.9,86 ,0. 7,98, 58.8 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A WN A un 1 .6 .9 86 .0 . 7 98.0 58. 8 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 26 8 .00 7198 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \e2 ' c:\e2 SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP STORM OPTIONS: 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE SPECIFY STORM OPTION: 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10,24 , 2 .9 ---------------------------------------------------------------------- ' ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2. 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- 1 ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0.9,86, 0.7, 98,58.8 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ' ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10, 24,2 .9 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** 10-YEAR 24-HOUR STORM **** 2 .90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TO FOR BASIN NO. 1 0. 9,86,0. 7, 98, 58.8 DATA PRINT-OUT: tAREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN ' 1 .6 .9 86. 0 . 7 98 .0 58.8 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) .44 8. 00 11803 ENTER [d: ] [path]filename[ . ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\e10 s ve- � 916 c:\e10 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: ' 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE ' SPECIFY STORM OPTION: 1 ' S.C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 100, 24, 3.9 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3. 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0. 9,86,0. 7, 98,58.8 ' 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 100,24,3 . 9 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** 100-YEAR 24-HOUR STORM . **** 3 . 90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 0. 9,86 ,0. 7,98 ,58.8 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN ' 1 . 6 .9 86.0 . 7 98.0 58.8 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 66 8. 00 17156 ' ENTER [d: ] [Path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c: \e100 c:\e100 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n STORM OPTIONS: ' 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM ' 3 - STORM DATA FILE SPECIFY STORM OPTION: 1 ' S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) ' 2 , 24 ,2 --------------------------------------------------------------------- 'J']k'�"Y C MVnr_lA nTCTVTVTTTT^%f ♦....♦.... ' .............. -�.-....T..--...'....-...--. . .v. .. aarc-1M uluinlavalvlr +-- --- -�.-..-- -..--r- - -- --- ********* 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 0.4 ,86, 0. 1 ,98,48.0 1 ' S.C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 2 ,24 ,2 ---------------------------------------------------------------------- ' ******************** S.C. S. TYPE-lA DISTRIBUTION ******************** ********* 2-YEAR 24-HOUR STORM **** 2.00" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ' ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0. 4,86,0 . 1 , 98,48 .0 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN ' . 5 .4 86. 0 . 1 98.0 48.0 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' .07 8.00 1860 ENTER [d: ] [pathlfilename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: c:\f2 c:\f2 ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n ' STORM OPTIONS: 1 - S.C.S. TYPE-lA 2 - 7-DAY DESIGN STORM ' 3 - STORM DATA FILE SPECIFY STORM OPTION: 1 S.C.S. TYPE-IA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 10 ,24, 2.9 -------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 10-YEAR 24-HOUR STORM **** 2 .90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0.4, 86, 0.1 , 98,48.0 1 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) ' 10, 24, 2 .9 -- ------- -------------- ------------------------------------ •r.Y4Y-W Yr--J--I----i---- I I. ....rPv I . Y......... ...... ' TTTTTTTTTTTT}}TTTT}T ,.V.�. lien.•—lA 111A1'AltsU11V14 TTTTTTT}TTTTT---TTTT ********* 10-YEAR 24-HOUR STORM **** 2 . 90" TOTAL PRECIP. ********* ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 0.4 ,86,0. 1 ,98,48.0 ' DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) ' A CN A CN . 5 .4 86 .0 . 1 98.0 48.0 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) ' . 13 8.00 3227 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 0: \f10 a :\flo ' SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP n STORM OPTIONS: 1 - S.C.S. TYPE-lA ' 2 - 7-DAY DESIGN STORM 3 - STORM DATA FILE SPECIFY STORM OPTION: 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 100 ,24, 3 .9 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** t ********* 100-YEAR 24-HOUR STORM **** 3 .90" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 ' 0. 4,86,0. 1 ,98,48. 0 ' 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) ' 100,24 ,3. 9 ----------------------------------------------------------------- ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3 ,90" TOTAL PRECIP. ********* ' ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 1 ' 0. 4,86 ,0. 1 ,98,48.0 DATA PRINT-OUT: ' AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN . 5 . 4 86.0 .1 98 .0 48 .0 PEAK-Q(CFS T-PEAK(HRS4 J,J VOL(CU-FT)yesZ 7!1 � O /�/� A0C.1 ' For two 4 foot diameter pipes: SUMMARY OF INPUT ITEMS ' 1) TYPE OF FACILITY: TANK 2) TANK DIAMETER(ft), STORAGE DEPTH(ft): 4.00, 4.00 3) VERTICAL PERMEABILITY(min/in): .00 ' 4) PRIMARY DESIGN HYDROGRAPH FILENAME: b:Sitel00d 5) PRIMARY RELEASE RATE(cfs): 1.64 6) NUMBER OF TEST HYDROGRAPHS: 2 TEST HYD 1 FILENAME: b:sitel0de TARGET RELEASE(cfs): 1.10 1 TEST HYD 2 FILENAME: b:site2dev TARGET RELEASE(cfs): .54 7) NUMBER-OF-ORIFICES, RISER-HEAD(ft), RISER-DIAM(in): 3, 5.00, 12 8) ITERATION DISPLAY: NO ' BOTTOM ORIFICE: ENTER Q-MAX(cfs) 0.5 DIA.= 3.04 INCHES t MIDDLE ORIFICE: ENTER Q-MAX(cfs), HEIGHT(ft) 1,1.9 DIA.= 5.04 INCHES ' TOP ORIFICE: ENTER HEIGHT(ft) 3 DIA.= 2.27 INCHES ' PERFORMANCE: INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD (Q100): 3.16 1.64 1.64 3.99 12535 TEST HYD 1: (Q10) 2.19 1.10 1.02 2.70 8980 ' TEST HYD 2: (Q2) 1.35 .54 .55 1.99 6240 STRUCTURE DATA: R/D TANK (FLAT GRADE) ' RISER-HEAD TANK-DIAM STOR-DEPTH TANK-LENGTH STORAGE-VOLUME 4.00 FT 4.00 FT 4.00 FT 998.4 FT 12535 CU-FT TRIPLE ORIFICE RESTRICTOR: DIA(INCHES) HT(FEET) Q-MAX(CFS) BOTTOM ORIFICE: 3.04 .00 .500 MIDDLE ORIFICE: 5.04 1.90 1.000 TOP ORIFICE: 2.27 3.00 .140 ' ROUTING DATA: ' STAGE(FT) DISCHARGE(CFS) STORAGE(CU-FT) PERM-AREA(SQ-FT) .00 .00 0.0 .0 .40 .16 653.0 .0 .80 .22 1786.3 .0 ' 1.20 .27 3165.6 .0 1.60 .32 4686.4 .0 1.90 .34 5874.0 .0 ' 2,00 .57 6273.2 .0 2.40 .88 7859.9 .0 2.80 1.07 9380.7 .0 3.00 1.16 10093.5 .0 ' 3.20 1.30 10760.0 .0 3.60 1.48 11893.4 .0 4.00 1.64 12546.4 .0 AVERAGE VERTICAL PERMEABILITY: .0 MINUTES/INCH 1 t t 1 _ - 1 Ii2 �i�/7ai^/ S c�/D O� OiSTR/c% - - - - _- 0, 07 svBr�rAa c — --- - - - ----_fig. _ _�,—y z .01 / 5 19 l Q cp , 00� t 9 . 6z /3c I'v �-Q - 7- 7v —IL — 3 6 ��,8_ .Aiz�.-� 7 Z---s-c y d y JJ5•�' 1-8 �-� ��E ON , I I � I I I I I I I I I I II � V1 I I I I I I I II I N I i I I I I I /dj�xi 117^1G I I i I I I ' I I N I i ! � ,2 �9�..�:�p !��4r, � �r3 rrs� .r��.,'J�ice✓ ' iI II I � I I I I I I i I I I I •'i li I ILI, Pressure Pipe Analysis & Design ' Circular Pipe Worksheet Name: Mission Hills Comment: Honey Dew Elementary School bypass pipeline ' Solve For Diameter Given Input Data: 400 . 00 ft ' Elevation @ 1• • . . . .00 psi 390 .00 ft Pressure @ 1. • . . • ' Elevation @ 2 • • • • ' 0 .00 psi Pressure @ 2 • " 1938 . 95 gpm Discharge- 5 .00 ft Length. . . . . . . . . . " 45 455 .00 Hazen-Williams C. . ' Computed Results: 16 . 66 in Diameter. . . . . . . . • 2. 86 fps ' Velocity. . . . . . . . . . 1 . 00 ft Headloss ad e @• • 1"" • 400 . 13 ft Energy Grad 399 . 13 ft Energy Grade @ 2 . • Friction slope. . . . 2. 198 ft/1000 ft 1 1 en Channel Flow Module, Version 3 .21 (c) 1990 Op ' op Methos, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 e n Channel ' HARMSEN&ASSOCIATES, INC. June 25, 1992 MISSION HILLS DRAINAGE ANALYSIS HAI #E-140-07-91 APPENDIX C -GEOTECHNICAL INVESTIGATION FOR STORM WATER INFILTRATION ' Data Report Geotechnical Investigation for Storm Water Infiltration Mission Hills Residential Development ' King County Prepared by Couvrette Geotechnical Engineering 1 1 17614-162nd Street BE•PO Box 516•Monroe,Washington•(206)794-7811 [Fax 743-27371 DATA REPORT GEOTECHNICAL INVESTIGATION FOR STORM WATER INFILTRATION MISSION HELLS RESIDENTIAL DEVELOPMENT KING COUNTY FOR ALLIED INVESTMENTS INC. 1 1 COUVRETTE ' GEOTECFIN cAL ENGINEERING 1' 17406 - 133RD AVENUE NORTHEAST WooDINva.LE,WASHINGTON 98072 (206)486-1669 March 31, 1992 Gary 5enescu Allied Investments Inc. 9512 State Highway 16 Gig Harbor, Washington 98335 Dear Sir: Data Report Geotechnical Investigation for Storm Water Infiltration Mission Hills Residential Development King County CGE File No. 316-01 INTRODUCTION This report presents the results of my geotechnical investigation at your planned Mission Hills development located at the east side of Renton. The site is located south of NE loth Street between Union Avenue NE and 138th Avenue SE in unincorporated King County. You have retained me to investigate the site and to provide data to be used for the design of storm water infiltration trenches. A site layout map by Harmsen and Associates, Inc. dated December 12, 1991 has been provided to me for use in this study. The development consists of 25 lots and associated roadways that access onto NE loth Street. The planned storm water system would have used infiltration trenches to dispose of all of the storm water on site. Preliminary data has been presented verbally to you and you have done some redesign, eliminating some of the infiltration trenches. SCOPE The purpose of my services on this project is to explore site infiltration characteristics and to provide you with geotechnical engineering recommendations for the infiltration system. The review of other geotechnical aspects of site development were not requested. Specifically, my services include: 1. Explore subsurface conditions at the site by excavating eight test pits. 2. Perform sub-surface infiltration tests at three locations. ' 3. Present the geologic and infiltration data in a written report. Data Report Mission Hills Development File No. 316-01 March 31, 1992 Page 2 ' SITE CONDITIONS SURFACE CONDITIONS The site contains four characteristically different areas with respect to general topography, vegetation and subsurface conditions. The central portion of the site surface is near-level to gentle sloping down to the south. The site to the west and east of this area slope gently to moderately up to the west and east respectively. The northern portion of the site is nearly level. Elevation differences of up to 15 to 20 feet exist on the property. The ground surface appears generally to be native with surficial disturbances due to logging and gardening. Vegetation on the central portion of the site consists of grass, brush, some isolated trees and scattered areas with evergreens. The higher western and eastern parts have mainly evergreen forest and the northern part contains a residential structure and garden. The south central portion of the site had an area of standing water at the time of the field inspection. SUBSURFACE CONDITIONS Subsurface Explorations: The subsurface conditions were explored by excavating eight test pits using a backhoe. The test pits were located in areas where the infiltration trenches were to be located. The test pits ranged in depth from 3.5 to 8.0 feet below the ground surface. A subcontracted geologist was used to monitor the excavations, maintain logs of the soils encountered and perform infiltration tests. The location of the test pits are shown on the Site Plan, Figure 1. The soils were visually classified in general accordance with the Unified Soil Classification System, a copy of which is shown on Figure 2. The logs of the test pits are presented on Figures 3 through 8. The elevations of the test pits are estimated based on contours shown on the Site Plan. Test pits 1, 2 and 5 were excavated at or near the three proposed infiltration pipe locations. These locations appeared to be unsuitable for the infiltration trenches because of soil and/or groundwater conditions. Other test pits were excavated to locate areas better suitable for infiltration ' tests. The conditions observed near Test Pits 3, 4 and 7, appeared favorable for infiltration. A test pit was excavated 6 to 7 feet horizontally from these three test pits and infiltration tests were performed according to the King County, Washington, Surface water design manual, Section 4.5.2: Sub-Surface Infiltration Test. The initial test pit data was used to determine the depth of the infiltration test. The excavation adjacent to TP-7 was further excavated after the infiltration test had been completed. A large water truck was used during our testing to provide water for presoaking and testing. ' COUVRETTE GEOTECHNICAL ENGINEERING Data Report Mission Hills Development File No. 316-01 March 31, 1992 Page 3 Subsurface Conditions: The subsurface conditions observed in the test pits consist of outwash or drift over till with local areas of fill on top. The thickest fill was observed in Test Pit 2 at 4.5 feet thick. The fill consists of a medium dense to dense silty sand with gravel and organics. The outwash was encountered west of the central area to a depth of 4.2 feet in Test Pit 3 and consists of a medium dense layered sand with gravel. The drift which extended to a maximum depth of 5.9 feet in Test Pit 7 consists of a medium dense to very dense sand and gravel with intermediate layers with variable amounts of silt. The till is a very dense sand with gravel and silt. The upper parts of the drift or till are typically weathered and less dense. ' Groundwater or seepage was observed in all but two of the test pits. The groundwater appears to be perched on the till or silty layers in the drift. The outwash soils and portions of the drift would be suitable for use with the infiltration trenches. The problem with the drift is whether it is consistent enough to maintain infiltration characteristics needed over the length of the trench. DESIGN DATA AND RECOMMENDATIONS The infiltration data is presented on graphs which are attached to this report as Figure 9. The till should be considered essentially impermeable and not capable of supporting an infiltration trench. The drift should be considered to have varying characteristics. A design using the test data in the drift should include an additional factor of safety to allow for variations. The alternative would be to conduct large scale infiltration tests. The elevation of the top of the till and underlying impervious soils will be critical for design. This should be used to determine final site grading and building crawl space elevations. Crawl space ' elevations that are below or near the elevation of the till should be expected to have some ground water during the wet time of the year. USE OF THIS REPORT This report has been written for Allied Investments Inc. and its designers for their use on a ' portion of this project. The final design was not available at the time this report was written. I recommend that I be retained to review the final plans with respect to my conclusions and recommendations and other potential geotechnical considerations. The data and report should be provided to prospective contractors for their bidding or estimating purposes, but my report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. The scope of my services does not include services related to construction safety ' COUVRETTE GEOTECIINICAL ENGINEERING Data Report Mission Hills Development File No. 316-01 March 31, 1992 Page 4 ' precautions and my recommendations are not intended to direct the contractors' methods, techniques, sequences or procedures, except as specifically described in this report for considerations in design. There are possible variations in subsurface conditions between the explorations and also with time. A contingency for unanticipated conditions should be included in the budget and schedule. I should be retained to provide monitoring and consultation services during construction to confirm that ' the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork and foundation installation activities comply with contract plans and specifications. Within the limitations of scope, schedule and budget, my services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No other conditions or warranty, express or implied should be understood. It has been a pleasure to provide service to you on this project. If you have any questions or require further information, please call. 45 WASDLG Yours very truly, eof k��cAa Couvrette Geotechnical Engineerin a vq9z zozas Charles P. Couvrette SS��NAL ECG ' EXPIRES ' Three copies submitted Nine Figures ' COUVRETTE GEOTECHNICAL ENGINEERING 1 1, SITE PLAN SCALE I INCH c 100 FEET 1 NE Io-rK STREET ! rESTPIT NUNB1<P. 1 NNa APPILDXI MATE LDch71oN 5 1 pG 2 TeVr -A S T P•r ET Test / 2 s �S 1 Tel 3 1 7 1 REFERENCE : r11SiION HILLS PRELIHINARy 1 PLAT UTILITY PLAN COUVpF-TT-E GEOTECHNICAL- ENCHNEERINC- CHf=GT 'a--OF 3 h-11-91 FILE No . 31 6 -01 1 NY HARNiEN AND hSioLIATES ,=Nc. FI Ca IA (kF- I 1 t '1 e SOIL CLASSIFICATION SYSTEM 'I MAJOR DIVISIONS GROUP GROUP NAME SYMBOL ' COARSE GRAVEL CLEAN GW WELL GRADED GRAVEL, FINE TO' COARSE GRAVEL GRAINED GRAVEL MORE THAN 50% OF GP POORLY-GRADED GRAVEL SOILS COARSE FRACTION '- RETAINED ON NO. 4 GRAVEL WITH GM SILTY GRAVEL SIEVE FINES MORE THAN 50% GC CLAYEY GRAVEL RETAINED ON THE WELL-GRADED SAND, FINE TO NO. 200 SEIVE SAND CLEAN SAND SW COARSE SAND SP POORLY-GRADED SAND ,•: MORE THAN 50 % OF SAND WITH SM SILTY SAND COARSE FRACTION FINES PASSES NO. 4 SIEVE Sc CLAYEY SAND FINE SILT AND CLAY ML SILT GRAINED INORGANIC CL CLAY SOILS LIQUID LIMIT LESS THAN 50% ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT MORE THAN 50% SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC PASSES ON THE INORGANIC NO. 200 SEIVE CH CLAY OF HIGH PLASTICITY, FAT CLAY LIQUID LIMIT 50% OR MORE ORGANIC OH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: SOIL MOISTURE MODIFIERS: 1. FIELD CLASSIFICATION IS BASED ON VISUAL EXAMINATION OF SOIL IN GENERAL ACCORDANCE DRY- ABSENCE OF MOISTURE, DUSTY, DRY WITH ASTM D2488-83. TO THE TOUCH 2. SOIL CLASSIFICATION USING LABORATORY TESTS MOIST- DAMP, BUT NO VISIBLE WATER IS BASED ON ASTM D2487-83. 3. DESCRIPTIONS OF SOIL DENSITY OR CONSISTENCY WET- VISIBLE FREE WATER OR SATURATED, ARE BASED ON INTERPRETATION OF BLOWCOUNT USUALLY SOIL IS OBTAINED FROM BELOW WATER TABLE DATA, VISUAL APPEARANCE OF SOILS, AND/OR TEST DATA. 1 '. COUVRETTE GEOTECHNICAL ENGINEERING FILE NO. 316-01 ' FIGURE 2 LOG OF TEST PITS DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION TEST PIT ONE ELEVATION: <405 FEET 0.0- 1.2 SM DARK BROWN SILTY SAND WITH SCATTERED GRAVEL AND ORGANICS (LOOSE, SATURATED) 1.2- 3.5 SP-SM GREY AND BROWN SAND WITH SILT AND GRAVEL (DENSE TO VERY DENSE, WET) (WEATHERED TILL) 3.5 -4.0 SM GREY SAND WITH SILT AND GRAVEL(VERY DENSE, WET) (TILL) TEST PIT COMPLETED AT 4.0 FEET ON 312/92 WATER AT SURFACE TEST PIT TWO ELEVATION: 407 FEET 0.0 -4.5 SM GREY BROWN WITH DARK BROWN TO BLACK SILTY SAND WITH GRAVEL AND WOOD (MEDIUM DENSE TO DENSE, MOIST) (FILL) ' 4.5 - 8.0 SM BROWN SILTY SAND WITH GRAVEL CHANGES TO SP-SM GREY SAND WITH GRAVEL AND SILT AT 6.0 FEET (DENSE, WET TO SATURATED) (DRIFT OR TILL) 1 TEST PIT COMPLETED AT 8.0 FEET ON 312192 VERY STRONG WATER SEEPAGE FROM 4.5 FEET ' DOWN, FILLS UP TO 3.8 FEET ' COUVRETTE GEOTECHNICAL ENGINEERING FILE NO. 316-01 ' FIGURE 3 LOG OF TEST PITS DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION 'I PIT THREE ELEVATION: 408 FEET 0.0 - 0.2 DARK BROWN ORGANICS(LOOSE, MOIST) 0.2 - 4.2 SW BROWN LAYERED MEDIUM SAND WITH FINE AND COARSE SAND AND SCATTERED GRAVEL GRADING INTO MEDIUM TO COARSE SAND WITH FINE SAND AND SCATTERED GRAVEL, LAYERS SAND WITH GRAVEL(MEDIUM DENSE, LOCALLY DENSE, DAMP TO WET AT 3.6 FEET) (OUTWASH) 4.2 - 4.5 SM GREY SAND WITH SILT AND GRAVEL(VERY DENSE, DAMP)(nl L) TEST PIT COMPLETED AT 4.5 FEET ON 312/92 GROUND WATER FILLS UP TO 3.7 FEET INFILTRATION TEST# 1 AT 3.1 FEET, 6 FEET FROM TP-3 COUVRETTE GEOTECHNICAL ENGINEERING FILE NO. 316-01 ' FIGURE 4 LOG OF TEST PITS DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION TEST PIT FOUR ELEVATION: 407 FEET 0.0-0.2 SM DARK BROWN SILTY SAND WITH SCATTERED GRAVEL AND ORGANICS (LOOSE, MOIST) 0.2-2.8 SM BROWN SILTY SAND WITH GRAVEL AND ROOTS (MEDIUM DENSE, MOIST) 2.8 - 3.5 GP BROWN LAYERED GRAVEL WITH FINE TO COARSE SAND AND TRACE SILT (DENSE, WET) (WEATHERED DRIFT) 3.5 -4.1 GP/SP BROWN GRAVEL AND SAND WITH TRACE SILT (VERY DENSE, WET) (DRIFT) 4.1 -5.2 SM GREY SAND WITH GRAVEL AND SILT(VERY DENSE, DAMP) (TILL) TEST PIT COMPLETED AT 5.2 FEET ON 3/2/92 WATER SEEPAGE FROM 4.1 FEET DOWN, FILLS UP TO 3.3 FEET INFILTRATION TEST#2 AT 3.0 FEET, 6 FEET FROM TP-4 TEST PIT FIVE ' ELEVATION: NO CONTOUR DATA 0.0 - 1.0 SM DARK BROWN TO BLACK SILTY SAND WITH ORGANICS (LOOSE, MOIST) (FILL) ' 1.0 -2.0 SM BROWN TO GREY BROWN SILTY SAND WITH GRAVEL(DENSE, WET) (WEATHERED TILL) ' 2.0 -3.8 SM BROWN GREY TO GREY SAND WITH GRAVEL AND SILT(VERY DENSE, DAMP) (TILL) ' TEST PIT COMPLETED AT 3.8 FEET ON 3/2/92 MODERATE SEEPAGE FROM 1.7 FEET DOWN 1 ' COUVRETTE GEOTECHNICAL ENGINEERING FILE NO. 316-01 ' FIGURE 5 LOG OF TEST PITS ' DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION ' ELEVATION: 407 FEET TEST PIT SIX 0.0 -0.3 SM DARK BROWN SILTY SAND WITH SCATTERED GRAVEL AND ORGANICS (LOOSE, MOIST) 0.3 - 1.2 SM BROWN SILTY SAND WITH SCATTERED GRAVEL AND TRACE ROOTS (LOOSE, WET) 1.2 -2.5 SM GREY WITH BROWN SILTY SAND WITH SCATTERED GRAVEL AND THIN SAND LENSES (DENSE, WET TO SATURATED)(DRIFT) 2.5 -3.5 SM GREY SAND WITH GRAVEL AND SILT(VERY DENSE, MOIST)(TILL) TEST PIT COMPLETED AT 3.5 FEET ON 312/92 WATER SEEPAGE AT 2.2 FEET, FILLS UP TO 2.6 FEET 1 ' COUVRETTE GEOTECHNICAL ENGINEERING FILE NO. 316-01 ' FIGURE 6 ' LOG OF TEST PITS DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION 1 ' ELEVATION: 407 FEET TEST PIT SEVEN ' 0.0- 0.6 SM DARK BROWN SILTY FINE SAND WITH SCATTERED GRAVEL AND ORGANICS/ROOTS (LOOSE, DAMP) 0.6 - 3.2 SM BROWN SILTY SAND WITH GRAVEL AND TRACE ' ROOTS (MEDIUM DENSE TO DENSE, DAMP) 3.2-4.9 SM/GP-SM BROWN LAYERED SILTY SAND WITH GRAVEL AND WITH LAYERS OF GRAVEL WITH SAND AND SILT BELOW 4.2 FEET (MEDIUM DENSE TO DENSE, MOIST) (DRIFT) 4.9 -5.9 SW GREY COARSE SAND WITH MEDIUM SAND AND FINE GRAVEL(DENSE TO VERY DENSE, MOIST) (OUTWASH OR DRIFT) 5.9 - SP-SM GREY SAND WITH GRAVEL AND SILT(VERY DENSE, DAMP) (TILL) TEST PIT COMPLETED AT 5.9 FEET ON 312/92 NO SEEPAGE OBSERVED 1 t 1 1 1 ' COUVRETTE GEOTECHNICAL ENGINEERING ' FILE NO. 316-01 FIGURE 7 ' LOG OF TEST PITS DEPTH UNIFIED SOIL SOIL DESCRIPTION (FEET) CLASSIFICATION ' TEST PIT SEVEN-A (LOCATED 7 FEET EAST OF TP-7) ELEVATION: 407 FEET 0.0-0.9 SM DARK BROWN SILTY SAND WITH SCATTERED GRAVEL AND ORGANICS(LOOSE, DAMP) 0.9-2.3 SM BROWN SILTY SAND WITH GRAVEL AND TRACE ROOTS(MEDIUM DENSE, DAMP) 2.3 -5.0 SM/ GREY BROWN TO BROWN GREY LAYERED SILTY SP/GP-SM SAND AND GRAVEL TO SAND AND GRAVEL WITH SILT, GRAVEL LAYERS FROM 4.5 TO 5.0 FEET (DENSE, LOCALLY MEDIUM DENSE, MOIST)(DRIFT) 5.0-5.3 SW GREY AND BROWN COARSE SAND WITH TRACE SILT(VERY DENSE,WET)(OUTWASH OR DRIFT) TEST PIT COMPLETED AT 5.3 FEET ON 3/2192 NO SEEPAGE OBSERVED INFILTRATION TEST#3 AT 3.0 FEET r 1 ' COUVRETTE GEOTECHNICAL ENGINEERING ' FILE NO. 316-01 FIGURE 8 C? I F(£ M 7M'1 MJN�1 Y�7M'' 9 z W i Q Y % / �Sz-c=rh7VV c1 SI'E-onyy °z c '" Cl'4 =("04tl 16•o y°uy.. ho 1 o 9 r -6 � J 0 5 ^ r N�-d1 h-dt E d1 1 HARMSEN&ASSOCIATES, INC. MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 HAI #E-140-07-91 APPENDIX D - NEED FOR REGIONAL DETENTION FACILITY t Letter to Tom Kress, PE City of Renton 1 1 1 17614-162nd Street SE•PO Box 516•Monroe,Washington•(206)794-7811 (Fax 743-2737] HARNISEN & ASSOCIATES, INC. Professional Civil Engineering and Land Surveying ' June 25, 1992 Tom Kress, PE City of Renton ' Utility Engineering Supervisor Storm water/Waste water Planning/Building/Public Works Department Municipal Building 200 Mill Avenue South Renton, Washington 98055 REFERENCE: REGIONAL STORM WATER DETENTION FACILITY ' Dear Mr. Kress, I have prepared a Conceptual Drainage Plan for the proposed Mission Hills subdivision located south of NE 10th Street at the southern end of Anacortes Avenue. During my field investigation of the site and the upstream and downstream drainage systems I identified general deficiencies in the storm drainage facilities for the area. I was also approached by a resident of Honey Dew Estates Division No. 2, Mrs. ' Key, who described the flooding problems in the area. Mrs. Key has been in contact with City Staff and has provided photographs of recent flood events. Currently the drainage facilities downstream of our project are severely compromised. The detention pond for the Renton Church of the Nazarene has been partially filled with land clearing debris. The inlet and outlet pipes have had their ends crushed and the outlet structure has had the grate removed and has been filled in. The Renton School District has built play fields in the natural drainage channel and has ' installed a bypass pipeline which has its' inlet and outlet structures buried. There are no provisions for biofiltration in either of the system. The play field functions as a dam, impounding storm water to a depth of approximately 3 feet, approximate elevation 403, which backs water up across the church ' property, to the south boundary of the Mission Hills site. Installation of a bar cone grate rather than a standard catch basin grate would decrease the impoundment but would not eliminate it. The school's bypass pipeline has a capacity of approximately 1.81 cfs which is less than the calculated runoff from the t Mission Hills site. In addition to the runoff from the Mission Hills site, the bypass pipeline also needs to have the capacity to transmit the runoff from the church property and the off-site inflow to the Mission Hills site. The developer, Mr. Gary Senescu, has approached the School District with the offer to replace the existing bypass pipeline and catch basins with a system designed to accommodate the storm water flow and to minimize the potential for burial of the inlet and outlet. Additionally we have contacted the ' developer of the Orchards development which is adjacent to the southern boundary of the School District's play fields. Their Project Engineer has reviewed my calculations for the School District's bypass pipeline and have sized their conveyance facilities to accommodate the storm water flows. While the developments proposed for this area will be designed and constructed in accordance with the City of Renton's Drainage Ordinance there is still the potential for an enhancement of the regional storm water drainage system. The creation of a regional storm water biofiltration and detention facility on the ' southern most parcel of the Renton School District's property, in conjunction with the replacement of the school's bypass pipeline would provide the opportunity solve the regional storm water problems. The ' 1 761 4-1 62nd Street SE' PO Box 516'Monroe,Washington 98272'(206)794-7811 [FAX 743-2737] 1 TOM KRESS, PE June 25, 1992 Page 2 ' parcel is 9.84 acres of wooded field with the confluence of two natural open channels. The areas adjacent to our site and the area east of our site both drain via open channel flow to this parcel. The parcel is earmarked as the Apollo School site by the School District. I would like to suggest that the feasibility of purchasing the property from the School District and ' constructing a wetland park which includes the functions of biofiltration, sedimentation, detention, and controlled release be investigated. This facility could be similar to the North Creek Regional Storm Water Detention Facility currently being designed for the Snohomish County Parks and Recreation Department. The North Creek facility is to be constructed adjacent to the southern boundary of the City of Mill Creek in an area that is very similar to this location. The school site is currently vacant and is logically located to solve the flooding in two upstream sub basins in addition to attenuating the runoff peaks experienced by the systems downstream. The present bypass pipeline should be replaced or ' abandoned and the flow directed to the eastern boundary of the play field area and then south to the biofiltration swale, in a constructed open channel. During the final design of the Mission Hills subdivision I will be calculating outflow hydrographs from the ' site. Additionally I will be calculating the off-site runoff which enters, and is bypassed through, our site. These hydrographs could be combined with hydrographs calculated forthe church property and the northern two parcels of school district property. This combined hydrograph would be the design inflow ' from the western upstream sub-basin. The eastern upstream sub-basin inflow hydrograph could be similarly calculated. HARMSEN&ASSOCIATES, INC. would be available to assist in the determination of design inflows, performance criteria, and site surveying and layout for the facility. ' Thank you for the consideration of this solution to the flooding in the area between NE 1 Oth and NE 4th Streets and Union (132nd) and Duvall (138th) Avenues SE. ' I look forward to your review of my Conceptual Drainage Plan. Sincerely, ' HARMSEN&ASSOCIATES, INC. 1 Perry R. Cole, PE Project Engineer cc: File E-140-07-91 t 1 1 HARMSEN&ASSOCIATES, INC. ' MISSION HILLS DRAINAGE ANALYSIS June 25, 1992 HAI #E-140-07-91 1 1 APPENDIX E - LETTER CONCERNING DOWNSTREAM CONVEYANCE FACILITIES 1 1 ' Letter from Edgar T. Jones, PE DODDS ENGINEERS, INC. 1 ' 17614-162nd Street SE• PO Box 516•Monroe,Washington•(206)794-7811 [Fax 743-2737] t DDDDS ENGINEERS, INC. CIVIL ENGINEERING S U R V E Y I N G RLANNING t June 16, 1992 J04 F a DEI Project No. 88008 ' Mr. Perry Cole Harmsen & Associates ' PO Box 518 Monroe WA 98272 Subject: Mission Hills tDear Mr. Cole: ' We have reviewed your calculations dated June 5, 1992 for upsizing the existing storm drain beneath the Honey Dew Elementary School for the above-subject project. You have proposed an 18 inch culvert to convey a 25 year flowrate of 4.32 cubic feet per second (cfs). We have preliminarily sized the Orchards conveyance system to ' convey a flow in excess of 4.32 cfs and thus are proposing to accommodate this flowrate. ' In order for the Orchards development to convey this flow by gravity while not creating excess fill for the extension of NE 8th Street, we request the invert elevation of the proposed 18 inch culvert be set at 399.50 (City of Renton vertical ' datum) in the vicinity of the NE 8th Street right-of-way. Please contact me if you have any questions regarding the above or if I may be of further assistance. ' Very truly yours, ' DODDS ENGINEERS, INC. JjEar on e E. .] nn eer ' ETJ:sab ' cc: Craig Krueger Northward Properties 1 1 ' 4205 148TH AVE. N.E., SUITE 200-BELLEVUE. WA 98007 [206] SS5-7677 OR 454-3743 FAX:[206]665-7963 t i i i 1 1 1 1