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Home My WebLink AboutSWP272901(2) f 1 STORM DRAINAGE REPORT STONE LANE PLAT CITY OF RENTON NO. PP-00-082 FOR WEST-TIER DEVELOPMENT CORP. DATE: November 16, 2000 . \Ft H A pF V4A,, "i g 70 BY: TOUMA ENGINEERS 6632 S. 191st PI. Suite E-102 KENT, WA. 98032 PH. 425-252-0665 c REOF ROC" a� FAX 425-251-0625 g) �� GUSTOWVM SOVIGE S7 L_�Uf) 00 - 0 S � TABLE OF CONTENTS CHAPTER. PAGES . I . PROJECT OVERVIEW . . . . . . . . . . . . . 1-4 II . PRELIMINARY CONDITIONS SUMMARY . . . . . . 5-6 Core and Special Requirements III . OFF-SITE ANALYSIS . . . . . . . . . . . . . 7-8 IV. RETENTION/DETENTION ANALYSIS AND DESIGN . 9-26 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN .27-30 VI . SPECIAL REPORTS AND STUDIES . . . . . . . 31 Bio-filtration . . . . . . . . . . . . . VII . BASIN AND COMMUNITY PLANNING AREAS . . . . 32 VIII . OTHER PERMITS . . . . . . . . . . . . . 33 IX. EROSION/SEDIMENTATION CONTROL DESIGN . . . 34 X. BOND QUANTITIES WORKSHEET, . . . . . . . 35 XI . MAINTENANCE AND OPERATIONS MANUAL . . . . . 36 XII . APPENDIX 37 T. PROJECT OVERVIEW The subject property covers an area of approximately 1 . 55 acres With 0. 16 acres to be dedicated for right of way. The property is situated in the northeast portion of the city. The site is bounded on the south by the Stone Court Apartments, bounded on the east by Queen Ave. NE and "The Village On Union" , on the north by single family residences, and on the west and northwest by Hilltop apartments and plat. Access to the property will be from Queen Ave. NE. The existing street improvements on the east side of Queen Ave NE, consist of 16 feet of asphalt pavement with curb and gutter. The Existing storm drainage along Queen Ave. NE. is directed south to a detention/infiltration system for "The Village On Union" project. Storm sewer, sanitary sewer, and water mains exist in the adjacent streets. The present zoning is residential - 10 dwelling units per acre (R-10) . This zoning designation allows for a minimum lot size of 3000 square feet and a maximum density of ten (10) dwelling units per developed acre. The proposed development of the subject property is consistent with the (R-10) zoning requirements. The entire neighborhood surrounding the property is designated with similar or supportive zoning. The project area has moderate slopes ranging generally from 5% to 16% sloping down from northeast to southwest. The soils are designated as Alderwood (AgC) in the King County Soil Survey. The soils are quite sandy around the old house site. The exiting residence and foundation has been removed. The proposed street section will consist of widening Queen Ave. NE to 32' of paving with curb gutter and sidewalk on the west side of the street. A dedication of 20 feet will make a total of 46 feet of right of way. This project will develop 14 lots in two tiers, 1 through 7 adjacent to Queen Ave N. The second tier of lots (8 through 14 will be served with 16 foot minimum of asphalt paved driveways within a 20 foot access easements. The north portion of the project site is covered with native brush and second growth, 12" to 24" fir trees. There was a single family residence that has been removed. A water meter box is still present along the west edge of the existing asphalt half street. The flow of any surface water on the site will be sheet flow. During a site visit in April 2000 we did not note any concentrated flows or streambeds entering or exiting the site. Surface flow will generally drain west and southerly. The newly constructed street, Queen Ave NE, has storm drainage catch basins and conveyance pipes directing developed runoff south. A detention/infiltration pond is located on the east side of Queen Ave. NE. at the southwest corner of The Village On Union. This proposed project will design and construct required detention and water quality facilities required by the City of Renton development codes. Pg. - 1 Will) ".v\ 2 I NC RI)SI 'IV IElsr NE ji,22NO sr 2210)PL IN z n�, cT 23Rn s h s T 2?NP ST t�, VO INE Is! $1 - Ife .7 RE 20TH 4 1-�qcx) ki T" S, 2300 WE 0 ,gill ST ve St 105111 Pt OPEO SPACE i HE 'y 20 ST OR, sr 1):1. - -Q 4111 sl !,- j.. I --p St 511t NIF TH ST " 5"'CREEK I "' 9 b i NE 19 1 ME. IB I ST F(AV V) PARK PA. ST NOME PI H C=3 .416 111 S, t 16 ST, __--- mrm:v 1� / - I —SUNSET kf PLGO 00 1 ME 1410 IV -itZ HE 14111 ST P to WE, 3TH PL ji HE .Av k 13111 ST __-to 15 121H ST IM: Sil NE 121.11 1 11-1 ". 2S1 ) =, ?I �0 Q w T 3700 St 14100 PL -1 1 .1 "1 1.. - va N OLIVI T H 111W tldil ME 11Y HAZI N a -1. 11 04 c.7 % w - ki, %IT" St HIS IVROY(I 1 4 111..I I;_-. !1.11 1 !-�j HE IH 3110 Me lows P( :I- ss ---T---- __ < RE 1010 ME t, i- HE 101" ST -Nt-ff-4 k-- .... ...7C r,4 51 fi KWIUTH LET J '00 ST ."1 "4 W ME ME 91" T06 M 91H ST p 9 NIS A FS ME a 16 film !LL 10 HI�ILA I) if cl E 8TH HE BTH 71H 11 PARK w 7 T.--At -7 1. VIO . ae 11 z'-p- NE 7fH HE st INS1 I ME 6TH �y RE IT ME-71.!1 a Aslll Sii- .1 WHO $2 1 t,ji, p e as I!� R ME c:f_ It I I" THE --w 7 6i H 61" STY. ME ME T at 1 NIAll! NE 014 Ali F. Siff S; 56,Vi Ilk, ME ki i. A�r,� I TIM AV 11 X RfNIf CD SE FFCIIJV CA f IfIVE'SM sl HILLS NE ■w COLUM 4T" SF 128111 Si ;ID&S ai i H'i I S r!Rk GREEI Woo oN j I T)111 HE 40RIAt < NE 3Rq_CT__ _P!ARKn"tu RAN(SITtl RE 2ND ST ME 'if lif-)it ■ 2ND I Off Mr r I'S 1 k,L1 MINT Of IVE I FS TA TIES Sri 1s1 l,, I v','Ili CFwrFRY 16 "Op 4'Pl sl SE A 0 AL. I-T I PARK le r st I ln'4 P, lin It SE. i4aii — PA SE 4 I,qltf r-i P. !1, RO SE S "I Irma "Ill ri v tA 141SI St V At•k 14, 1 - ml R111/fRill W1 nav qp\ 1 -4 PARK 'VE PAR' - st wril, 57 IR 147NO ST CED R RIVER ip sr 1 I A TURAL ZONE GOtF et I 4,1 Cff)AR RIVtR r> 141� AV RF.GIONAI. r q\ 1A A7F "4111 i�N p PARK if(41 pt WIN t; qil W T-I JQ t E. a 'a (c_}\ rt•\\�F to /p 'o •. �f i , IS4,, WIN)) S,- • AV IS AIN Ile1111 PL 4 7— tA Isi ST SI ENT113F MAP CITY ()F RENION L. 9 2 3 5 KING COUNTY ASSESSOk F I* IV Ic a'D a 40 CD .,4 "k I Le! It J9 WT I 90.f 4qr T� T-.4 'W' M.- .1 337 70 —HILLTOP f "ok 'R.A �AIS _row "We F -------------- it 21.6 P3 3 MI,1730" r; Mi TO INTERSTATE 90 (40)I1kF (Joins sheet 5) AMC ISSAQUAH 12 MI. 10' -- • �• 11•, i�r _+ •'• •• - 1 i Amu i fa-- scn i.. :KR 7r,;• r I. ., , •jam: AgC •� 413 AgC r; ! 1 - l; 'AgB 7 '� :•• '•�o__I- ��•��..1 An � �Tl� � strai t11 �' .�' �� -, •• i� \I i � �., \II I fir 1 I -�7 � �� BM • �• �-- I 'i ♦�• • t/eil�r In.�`V� ,Js ``..A`fieldthlefic I t . f• T 9Fo I ' : --=T- i g• `` I. I I / �reenwooda ,; e. II "• •••» t t ... kF AgC ase h r m An t,dg� Park P� - y. GRAVEL !Prr �a 6 Bm 322 Evc hq4, o I j d PF ch AkP co — Ake i I F I ' � /� 1 _�--.t •• �...- L�S•F:iP >� �1�7.iL.'r� '• —SlM�—� -- _ —y+ 3t. • InT• — ,—` I � n• �. . '� ��y BM13� I ' AgC + • y�' y CO�j " =- �If _ Y AmC `a.,KY '''1• i t;4 -..\ AgC r �i� jE-*' Cod e y •, '�'•G -I t - - � ?ter. 'G'• •. \1 !7" ('('. ' �'i5. '� _-\_ - • subsea I . „ 1 •' AgC • ap o' ii e, pNg A90 20 i��a �1 `+y a 1t • ' '4 p� Ill. a- t 455 ABC 1t1`` ,111kF Akr Pal n•'J e �o�, , . , AtC 017 515 !1.BeC I , 4 �4P'.} \��"01 'y e • EVC. Ag210 C`. 1 AgC -A -e •-- gu'i p - A -- - qg� y •1 AmC " + • BM r� ' 7 45 203 •29 AgB �I Ur y� i' 16fl I AgC+ 1 z r ti,: .I ti �• • a to .•� F ` � �T+# rm i ^=' i r.. ;••r li'!o .. A ABD, M , m6 1 .'1b�E1IvnwTeK. Bid _ v� • MI 17-jar' - • 7. - ;�►- - - - •--'-- -';-ak-' ---- 91_:�,. : + ''-1�` !' .. - ° •: ��Avn II . PRELIMINARY CONDITIONS SUMMARY CORE REQUIREMENTS 1-5 CORE REQUIREMENT #1 : DISCHARGE AT NATURAL LOCATION The allowable outflows from the site will be discharged within there natural drainage basins and not rerouted to other drainage basins . CORE REQUIREMENT #2 : OFF-SITE ANALYSIS A level one downstream analysis is a portion of this report . See — the analysis later in this report below. CORE REQUIREMENT #3 : RUNOFF CONTROL The increased peak runoff, due to any change in pervious conditions and increase of impervious areas, will be attenuated using peak rate runoff control devices . These will include orifice control and runoff volume storage utilizing a concrete vault with included wetpond. CORE REQUIREMENT #4 : CONVEYANCE SYSTEM The conveyance system will be designed at a using the rational method. The drainage system will be designed to the City of Renton standards and specifications . The drainage runoff will be calculated using the King County modified rational method. The pipe system will be designed to handle a minimum 25-year storm. Then the system will be checked with a 100-year design situation to discover any overtopping situations . CORE REQUIREMENT #5 : EROSION/SEDIMENTATION CONTROL PLAN The erosion control plan will be designed using the King County storm manual . A series of sediment traps are anticipated at various locations . These will be situated and constructed to minimize any impact to downstream or offsite areas . Pg. - 5 Y t SPECIAL REQUIREMENTS : THOSE APPLICABLE TO PROJECT 1 . Critical Drainage Area - N/A 2 . Compliance with existing Master Drainage Plan - N/A 3 . Conditions Requiring Master Drainage Plan - N/A 4 . Adopted .Basin or Community Plans - N/A 5 . Special Water Quality Controls - N/A 6 . Coalescing Plate Oil/Water Separators - N/A 7 . Closed Depressions - N/A 8 . Use of Lakes, Wetlands, or Depressions for Detention - N/A 9. Delineation of 100 Year Flood Plain - N/A 10 . Flood Protection for Type 1 and 2 Streams - N/A 11 . Geotechnical Analysis and Report - N/A 12 . Soils Analysis and Report - Would be a portion of the Geotechnical Report . pg. - 6 III . OFF-SITE ANALYSIS CORE REQUIREMENT #2 : OFF-SITE ANALYSIS LEVEL 1 ANALYSIS The field inspection of the site was performed in April, 2000 . The proposed project site is presently vacant . A single family residence has been removed from the property. The east side of Queen Ave . NE has been developed with about 16 feet of paving, with curb and gutter and storm drainage system. No surface runoff enters the site from Queen Ave . NE. The drainage basin historically sloped to the southwest . The development of The Village On Union" has shunted runoff directly south toward NE 4th street . This is not considered diversion as the runoff is all reunited at the intersection of NE 4th street and Monroe Ave NE. , within, about a quarter mile downstream. We plan to utilize the existing drainage conveyance pipe system in Queen Ave . NE for the outfall from this proposed project . UPSTREAM The existing single family residence on the north drains it' s backyard to the south along our north boundary. This area is grassed and landscaped therefore we will consider this area as insignificant. To the east the storm drainage system in Queen Ave . NE. intercepts runoff and directs it southerly through it' s detention, infiltration bio-swale facilities . This system drains to a type 2 catch basin in Queen Ave . NE. DOWNSTREAM The site slopes to the southwest and south. There was no evidence of any concentrated flows leaving the site. The existing right of way abutting to the east is Queen Ave. NE. Adjacent to the southeast corner of the site within the right of way for Queen Ave NE. is an existing type 2 catch basin about 8 feet deep. The 60 foot 12" conveyance pipe carries runoff south to CB 13G 8-9 . Catch basin 13G 8-9 drains with a 24" concrete pipe flowing south about 276 feet to CB 13G 8-5 . Then 340 feet of 27" concrete pipe flow south to CB 13G 9-3 on the north side of NE 4th street . 48 feet of 27" concrete pipe flows to CB 13G 9-4 on the south side of NE 4th street . About 784 feet of 27" concrete pipe flow west to CB 13E 9-1 at Monroe Ave NE and NE 4th street . Pg. - 7 The Environmental Review Committee states that, down stream of the site, the conveyance system has experienced flooding along Queen Ave NE and NE 4th Street . The proposed new detention system should be designed to limit the 2-year, 10-year, and 100-year storms to the pre-developed rates for those events with a 30 percent safety factor for the 100-year storm event . Pg. - 8 �� I 1�-_J � I IV. RETENTION/DETENTION ANALYSIS AND DESIGN The drainage from the site was described above in the "Downstream analysis" section. Included in this section is the design of the detention system for the proposed 14 lot plat . The Geotechnical report for this site was prepared by Nelson- Couvrette & Associates Inc. The report states that areas of . glacial till are relatively impermeable and that the outwash - areas should be suitable for infiltration of roof drain runoff. From figure 2 of the report, areas for lots l through 4, and 8 .(7 through 12 will be calculated to use roof infiltration. For calculation purposes the houses on these 9 lots will be counted ` as lawn. See the attached " Developed Conditions" sketch. We are resubmitting a copy of the Geotechnical Report with this report. The proposed new detention system should be designed to limit the 2-year, 10-year, and 100-year storms to the pre-developed rates for those events with a 30 percent safety factor for the 100-year storm event . A concrete detention )vault with wetpond combination will be calculated for the entire 1 . 55 acres . See the attached sketches of the existing conditions and developed conditions . THE EXISTING AND DEVELOPED CONDITIONS AND TIME OF CONCENTRATIONS ARE AT THE END OF THIS SECTION. WETPOND CALCULATIONS The standard wetpond calculations for the final design are to be based on the following criteria: Design Water Volume - Based on the runoff volume from a hydrograph using one third of the 2 year storm for the drainage sub-basin. p2/3 = 0 . 67" ;,- Design Water Quality Peak Rate - Based on the peak rate of runoff from a hydrograph using the developed 2 year storm for the drainage sub-basin. Design Water Surface Area - Based on one percent of the impervious surface in the drainage sub-basin Pg. - 9 The hydrograph was calculated using 1/3 �f the 2-year rainfall intensity and the required volume isj'1346 CE . The water quality peak flow from the 2-year storm event is 0: 46 c The impervious surfc aea is :�0 - 6Trac x 43560� x 1% = 291 SF --� Determine and check vault size (inside dimensions) With 14 ' wide, 85 . 66 ' long: WETVAULT W/1 ' dead storage ('4�,',xl4' x4 . 51 ) + (3' xl4' x36 . 66' ) = 1729 cf. , 1346 CF Required ok SURFACE AREA 141x (4 . 50' +18 . 33' +18 . 33' ) = 567 SF. , r291 �F Required ok ✓ 3 . 75 ' live storage SA = 14 ' x 85 . 00' = 1190 SF. Live Vol . =1190x3 .75' _ .4462 . cf. 4453 CF Required ok SIZE WATER QUALITY ORIFICE (2-year dev. Peak = 0 . 46 cfs) H= 362 . 50 - 359 . 75 = 2 . 75 ' , d= ( (36. 88xQ) / (H) -5 ) .5 d= ( (36 . 88x0 . 46) / (2 . 75) 'S) 'S = 3 . 198" dia. Say 3 . 20" 3,15 Pg. - 10 a �� STAGE HEIGHT, TO PROVIDE A FACTOR OF SAFETY. ENTER: STORAGE-INCREASE(%) , STAGE-HEIGHT( ft ) 30 , 3 . 75 3D"/o /l�'Ic%UC- t4 ul PERFORMANCE : INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD : 1 . 15 . 58 . 50 3 . 33 3949 TEST HYD 1 : . 46 . 14 . 09 1 . 69 2000 TEST HYD 2 : . 78 . 34 . 24 2 . 54 3010 SPECIFY: D - DOCUMENT, R - REVISE, A - ADJUST ORIF, E - ENLARGE, S - STOP D 4u. Qvc-'4`J PERFORMANCE : INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD : 1 . 15 ►on-y . 58 _ . 50 3 . 33 3949 TEST HYD 1 : . 46,. Z" yam' . 1-4 . 09 1 . 69 2000 TEST HYD 2 : . 78 1b " Nlk- . 34 . 24 2 . 54 3010 STRUCTURE DATA: R/D-VAULT- RISER-HEAD VAULT-BOTTOM-AREA STOR-DEPTH STORAGE-VOLUME 3 . 75 FT 1187 . 7 SQ-FT 3 . 75 FT 4453 CU-FT DOUBLE ORIFICE RESTRICTOR: DIA( INCHES) HT(FEET) Q-MAX(CFS) BOTTOM ORIFICE : 1 . 63 . 00 . 140 TOP ORIFICE : 3 . 12 2 . 37 . 440 ROUTING DATA: STAGE(FT) DISCHARGE(CFS) STORAGE(CU-FT) PERM-AREA( SQ-FT) . 00 . 00 . 0 . 0 . 38 . 04 445 . 4 . 0 . 75 . 06 890 . 8 . 0 1 . 13 . 08 1336 . 2 . 0 1 . 50 . 09 1781 . 6 . 0 1 . 88 . 10 2227 . 0 . 0 2 . 25 . 11 2672 . 4 . 0 2 . 37 . 11 2814. 9 . 0 2 . 63 . 31 3117 . 8 . 0 3 . 00 . 42 3563 . 2 . 0 3 . 38 . 51 4008 . 6 . 0 3 . 75 . 58 4454 . 0 . 0 ---3 . 85 . 91 4572 . 7 . 0 3 . 95 1 . 49 4691 . 5 . 0 4. 05 2 . 23 4810 . 3 . 0 4. 15 3 . 04 4929 . 0 . 0 4 . 25 3 . 34 5047 . 8 . 0 AVERAGE VERTICAL PERMEABILITY: . 0 MINUTES/INCH SPECIFY: F - FILE, N - NEWJOB, P - PRINT IF/OF, R - REVISE, S - STOP it -- it 10 R/D FACILITY DESIGN ROUTII�$ SPECIFY TYPE OF R/D FACILITY : 1 - POND 4 - INFILTRATION POND 2 - TANK / 5 - INFILTRATION TANK 3 - VAULT 6 - GRAVEL TRENCH/BED 3 ENTER: EFFECTIVE STORAGE DEPTH( ft ) BEFORE OVERFLOW 3 . 75 , ENTER [d: ] [path]filename[ . ext] OF PRIMARY DESIGN INFLOW HYDROGRAPH: 1D100YR PRIMARY DESIGN INFLOW PEAK = 1 . 15 CFS ENTER PRIMARY DESIGN RELEASE RATE(cfs ) : . 58 ENTER NUMBER OF INFLOW HYDROGRAPHS TO BE TESTED FOR PERFORMANCE ( 5 MAXIMUM) : 2 ENTER [d: ] [path]filename[ .ext] OF HYDROGRAPH 1 : 1D2YR ENTER TARGET RELEASE RATE(cfs ) : . 14 ENTER [d: ] [path]filename[ . ext] OF HYDROGRAPH 2 : 1D10YR ENTER TARGET RELEASE RATE(cfs ) : . 34 ENTER: NUMBER OF ORIFICES, RISER-HEAD(ft) , RISER-DIAMETER( in) 2 ,3 . 75 , 12 RISER OVERFLOW DEPTH FOR PRIMARY PEAK INFLOW = . 24 FT SPECIFY ITERATION DISPLAY: Y - YES, N - NO N SPECIFY: R - REVIEW/REVISE INPUT, C - CONTINUE C INITIAL STORAGE VALUE FOR ITERATION PURPOSES : 5568 CU-FT BOTTOM ORIFICE : ENTER Q-MAX(cfs ) . 14 DIA. = 1 . 63 INCHES TOP ORIFICE : ENTER HEIGHT( ft ) 2 . 37 DIA. = 3 . 72 INCHES PERFORMANCE : INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD: 1 . 15 I00- 'i2 . 58 . 58 h!- 3 . 75 3423- TEST HYD 1 : . 46 0 - ye . 14 . 10 1 . 96 1780 TEST HYD 2 : . 78 10 - Ye . 34 . 34 2 . 75 2500 SPECIFY: D - DOCUMENT, R - REVISE, A - ADJUST ORIF, E - ENLARGE, S - STOP E P3 - i z ENLARGEMENT OPTION: ALLOWS FOR INCREASING STORAGE AT A SPECIFIED SINGLE HOUSE SCALE 1"=50' EX DRAINAGE 'S BASIN FROM EP �.,\ 1 :4 TO WEST PROPERTY ,, `6 1.55 ACRES F, 'S 7 A :1n Al ,��: PERVIOUS EX YARD 0.17 AC EX Rvoos 1.28 AC IMPERVIOUS HOUSE & GRAVFL 0.10 AC EXISTING C:ONDI TIONS (1.55 A G) 1—J9 AC BACK OF WALK ! 10 WEST PROPERLY LINE SCALE 1"-50' — f S=6.5X— N—0.15 $ �� i . a •-., r ti f i L=270' f S=2.6 i K=42 ro 817 Vollil n DEVELOPED ROW . ROAD & S1`W — 16 A OEVFLOPE. 14 LOTS lJ9AC) IMPERVIOUS 5 x 1800 SF ROOF = 9000 SF(21 AC) o ' TOTAL DEVELOPED i 14 x 20x24' D W — 6,720 SF(.15 AC) 4---COMMON 0 PERVIOUS — 0.88AC ;� G 4 x 105' x 1 — 6,720 SF(15 AC) y {` r/ IMPERVIOUS — .51 + .16 = 6 ,AC 22,440/43560 = 0.51AC PERVIOUS (LAWN, LANDSCAPING) t. 11 9x 1800 SF ROOF = 16,200 SF(..37 AC) DE VE L OPF_D COND!RONS � 1.J9 —• 0.51— 0.88 AC (1. 55 A C) 779DSKTC.DWG } p cklttc — Koo. (X, STORM DRAINAGE TIME OF CONCENTRATION FOR QUEEN AVE JOB TOTAL AREA 1.51 ACRES - PROPERTY BASIN AREA 1.55 ACRES - ON SITE AND OFF SITE SOIL TYPE AgC ALDERWOOD Type „C„ EXISTING CONDITIONS t EX HOUSE 0.1 ACRES CN 98 OPEN AREAS 1.28 ACRES CN 81 �'` EX YARD 0-17 ACRES CN 86 PERVIOUS AREA 1.45 CN 82 ,21 POST DEV. CONDITIONS LANDSCAPING 0.88 ACRES CN 86 HOUSE ROOF 0.21 ACRES CN t86 ASPHALT + CONCRETE (ROW) 0.16 ACRES/ CN 98 COMMON D/W 0.15 ACRES K CN 98✓ PRIVATE D/W 0.15 ACRES/ CN 98� PERVIOUS AREA 0.88 ACRES CN 86 IMPERVIOUS 04kD.67 ACRES CN 98 TIME OF CONCENTRATION - PRE-DEVELOPMENT - FOR 2-YEAR, 24-HOUR STORM DESIGN SHEET FLOW- ONSITE MANNING-i RANGE 0.4 T, OVERLAND-L 250 FEETY foZ�p.s C 'Qq So PRECIPITATION-P 2 INCH P" SLOPE - S 0.088 FT/FT T1 = 31.26 MINUTES 3t.Zro � TOTAL TIME -PRE- DEVELOPMENT 31.26 1 TIME OF CONCENTRATION — POST DEVELOPMENT - FOR 2—YEAR, 24-HOUR STORM DESIGN SHEET FLOW— ONSITE MANNING—i SURFACE 0.15 OVERLAND—L 135 FEET PRECIPITATION—P 2 INCH SLOPE — S 0.065 FT/FT,/ T1 = 9.83 MINUTES CONCENTRATED FLOW— ONSITE �-- PIPE 270 FEET K— VALUE 42 SLOPE — S 0.026 FT/FT VELOCITY—V 6.77 FPS i— T2 = 0.66 MINUTES s TOTAL TIME - POST DEVELOPMENT 10.50 (.r v JOB MUMA ENGINEERS SHEET NU, or WEST VALLEY EXECUTIVE PARK CALCULATED BY DATE 6632 SOUTH 191ST PLACE. SUITE E-102 KENT WA 98032 CHECKED BY DATE PHONE (425 251-0665 FAX (425) 251-0625 SCALE .... .. .... N ... -77�.... .............. .... ............. .... .... .......... .... ..... .... .... .. 46. ........................ .......... .... ......... ......... .. ............. ............... .. .. `.. ....... ... .. .. .. . ... ... . .......... .... .... .... .... .... LM .............. �\z .... ....... N .... .... m.... . .. .... Qi .............. . . . . . . . . . . Ll . . . . . . i i SIMPLE ORIFICE CALC'S d-(36.88Q/(h) .5) .5 PER KING COUNTY SECTION 4.4.7A a _ 3•�1 x iWATER QUALITY OR IFICE CALCULATION !LOWER ORIFICE --- -- _ - Q 2.75!ft — cfs — t' 0.461cfs DIA-IN = 3.198'in. 1 S .C. S. TYPE-lA RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP( INCHES) 1,24, . 67 ---------------------------------------------------------------------- ******************** S .C. S. TYPE-1A DISTRIBUTION ******************** ********* 1-YEAR 24-HOUR STORM **** . 67" TOTAL PRECIP. ********* �= L.P M � ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 1 . 45 ,82,, . 1,98,31. 26 V y �ASr= v fir! b F C2.4.7 DATA PRINT-OUT: 312) AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 6 1 . 5 82 . 0 . 1 98. 0 31 . 3 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 01 7 . 83 287 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: lE1YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP C ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 2 . 88,86 , . 67 , 98, 10 . 5 DATA PRINT-OUT: C)F_V AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 5 . 9 86 .0 . 7 98 . 0 10 . 5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) V 0 L FOLD W,4T P_ 4? . 08 7 . 83 1346 9 ENTER [d: ] [path]filename[ . ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1D1YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP 1 S .C . S. TYPE-1A RAINFALL DISTRIBUTION 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 1 . 45 ,82� . 1,98 ,31. 26 DATA PRINT-OUT: exis �f" Ckwbcr O AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 6 1 . 5 82 . 0 . 1 98 . 0 31. 3 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 14 8. 00 4039 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: lE2YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP C ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 . 88,86, . 67,98, 10 . 5 DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 5 . 9 86. 0 . 7 98 . 0 10 . 5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) V-/ - (9 l(n C F . 46 7 . 83 7022 ENTER [d: ] [path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1D2YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP (P-CA -) C � CN C p s) Tel � Q l�� ` 2 0 1 S .C . S . TYPE-1A RAINFALL DISTRIBUTION ENTER: FREQ(YEAR) , DURATION(HOUR) , PRECIP(INCHES) 10 ,24,2 . 9 ---------------------------------------------------------------------- ******************** S .C. S. TYPE-1A 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 . 45,, 82 , . 1,98,31 . 26 l l L 11 DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 6 1 . 5 82 . 0 . 1 98 . 0 31 . 3 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 34 7 . 83 7770 ENTER [d: ] [Path]filename[ .ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1E10YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP C ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 . 88,86 , . 67 ,98, 10 . 5 DATA PRINT-OUT : AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN 1 . 5 . 9 86. 0 . 7 98 . 0 10 . 5 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 78 7 . 83 11520 ENTER [d: ] [Path]filename[ . ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1D10YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP 1 S .C . S . TYPE-1A 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 . 45 ,82 , . 1 ,98 , 31 . 26 DATA PRINT-OUT : AREA(ACRES ) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN 1 . 6 1 . 5 82 . 0 . 1 98 . 0 31 . 3 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) . 58 7 . 83 12388 ENTER [d : ] [Path]filename[ . ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1E100YR SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP C ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A( IMPERV) , CN( IMPERV) , TC FOR BASIN NO. 2 . 88,86 , . 67 ,98, 10 . 5 DATA PRINT-OUT : AREA(ACRES ) PERVIOUS IMPERVIOUS TC(MINUTES ) A CN A CN 1 . 5 . 9 86 . 0 . 7 98 . 0 10 . 5 PEAK-Q(CFS ) T-PEAK(HRS ) VOL(CU-FT) 1 . 15 7 . 83 16748 ENTER [d : ] [Path]filename[ . ext] FOR STORAGE OF COMPUTED HYDROGRAPH: 1D100YR SPECIFY: C - CONTINUE , N - NEWSTORM, P - PRINT, S - STOP - LZ K I IN (; C O tf N 'I' Y, W A S 11 1 N (; '1' () N, S U R F A (' 1 W A TE R 1) I; S I (; N M A N IT A I, ----------- ------ — ------ — TABIX 3.5.211 SCS WESTERN WASIIINGTON RUNOF CURVE NUMBERS SCS WESTERN WASHING-TON RUNOFF CURVE NUMBERS (Published by SCS In 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for Type to ' rainfall distribtdion, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SOIL GROUP ' LAND USE DESCRIPTION A B C D Cultivated land(1): winter condition 86 91—91---95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed 42 64 76 81 ' Wood or forest land: young second growth or brush 55 72 8 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping, good condition: grass cover on 75% or more of the area 68 80 86 90 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots -- 72 82 87 89 — Impervious surfaces, pavement, roofs, etc. 98 98-- 9£�, - 98 Open water bodies: lakes, wetlands, ponds, etc. too 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre % Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 Impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, % impervious condominiums, apartments, must be computed commercial business and Industrial areas. (1) Fora more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed Into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 3.5.2-3 2/89 � - 23 KING COUNTY, WAS III NGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.5.1C 2-YEAR 24-HOUR ISOPLUVIALS .,1 _ � M 1, . rrt: :C .Y/ \•� J N I �r(p r, I _ 1= � IN iZL 2-9 r (fO Mew' pa Y T" War 0 1 ad .� l -yy on ow L •y:/ `t 2 ,v °" -------------------------- 2—YEAR 24-HOUR PRECIPITATION ,.3.4�'" ISOPLUVIALS OF 2-YEAR 24-HO �► - ^••- LL •%' 35 TOTAL PRECIPITATION IN INCHESry 0 1 2 3 4 S 6 7 8 Mlles 1:300,000 —Z y T M I/90 3.5.1-8 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 3.S.1E 10-YEAR 24-110UR ISOPLUVIALS 22,2 . l 24 v 27 wn, 3.0 33 V ' , 1 ' 14 \�, ice_).• � � - . ..�- -s � ! ` __ ., `l� -� 1. { lie � a y YEAR 24-HOUR PRECIPITATION r 3.4-10' ISOPLUVIALS OF 10-YEAR 24-HOUR TOTAL PRECIPITATION IN INCHES J• A � 0 1 2 3 4 5 6 7 8 Miles `� . l 3.5.I-I0 J I+iS 90 4.0 1 V. CONVEYANCE CALCULATIONS The conveyance calculations are based on the 25 - year and 100 year storms . The 100-year storm is used to check if there could be any backups . The following sheets show the area map and the calculations. Pg. -27 i L=155' - S=6.5%,J x _ W A=:24AC 1" = 50'. \ CB*8 T - 18 \ � L=120' S=7.2% 90L� 12" V\ -- S444% Q ; i P-8 J S o'� _ A=.34AC w - - 1-4 1-7341 -- 90LF 1 f( S=3.50 Y. TO BE A=.38 (gEMOVED 184LF 12" S=2 61 /CS#6: -6� --�- P GRAVEL/ - � - ---DRIVEi -- J 10'W 82LF 1�" S=1.04% �A=.38AC // 69LF�12"�/ CB# iS=1.02% W cB#5 i-5cB#�' J_2 P-3 1-3 tlet 24LF 1 _ S=3.75° CONVEYANCE CALCULATIONS 779CSKTC-DWG Project Title:TIERSMA Project Engineer:Mounir Touma c:\haestad\stmc\tiersma.stm Touma Engineers StormCAD v1.0 12I05100 10:18:30 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 Pipe Report Pipe Upstream Downstream Inlet Inlet Inlet Total System Discharge Length Constructed Section Roughness Capacity Upstream Downstream Upstream Downstream Node Node Area C CA CA Intensity (cfs) (ft) Slope Size (cfs) Invert Invert Ground Ground (acres) (acres) (acres) (in/hr) (fttft) Elevation Elevation Elevation Elevation (ft) (ft) (ft) (ft) P-8 1-8 1-7 0.24 0.73 0.17 0.17 2.73 0.48 90.00 0.044444 12 inch 0.012 8.14 368.50 364.50 372.00 368.00 P-7 1-7 1-6 0.34 0.62 0.21 0.38 2.63 1.02 90.00 0.035000 12 inch 0.012 7.22 364.50 361.35 368.00 364.25 P-6 1.6 1-5 0.38 0.58 0.22 0.61 2.55 1.56 82.00 0.010366 12 inch 0.012 3.93 361.35 360.50 364.25 365.40 P-5 1-5 J-1 0.38 0.58 0.22 0.83 2.50 2.09 85.00 0.001176 60 inch 0.012 96.77 359.85 359.75 365.40 367.00 P-4 1-4 1-3 0.06 0.90 0.05 0.05 2.73 0.15 184.00 0.026087 12 inch 0.012 6.23 368.50 363.70 372.20 367.20 P-3 1-3 J-2 0.10 0.90 0.09 0.14 2.43 0.35 59.00 0.010169 12 inch 0.012 3.89 363.70 363.10 367.20 366.40 P-2 J-2 J-1 N/A N/A N/A 0.14 2.38 0.34 50.00 0.001000 60 inch 0.012 89.22 359.80 359.75 366.40 367.00 P-1 J-1 Outlet N/A N/A N/A 0.97 1.98 1.94 24.001 0.037500 12 inch 0.0121 7.47 359.751 358.851 367.001 366.75 N Project Title:TIERSMA Project Engineer: Mounir Touma c:\haestad\stmc\tiersma.stm Touma Engineers StormCAD v1.0 11/29/00 16:29:41 Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 (203)755-1666 Page 1 of 1 Pipe Report Pipe Upstream Downstream Inlet Inlet Inlet Total System Discharge Length Constructed Section Roughness Capacity Upstream Downstream Upstream Downstream Node Node Area C CA CA Intensity (cfs) (ft) Slope Size (cfs) Invert Invert Ground Ground (acres) (acres) (acres) (in/hr) (ft/ft) Elevation Elevation Elevation Elevation (ft) (ft) (ft) (ft) P-8 1-8 1-7 0.24 0.73 0.17 0.17 3.19 0.56 90.00 0.044444 12 inch 0.012 8.14 368.50 364.50 372.00 368.00 P-7 1-7 1-6 0.34 0.62 0.21 0.38 3.08 1.19 90.00 0.035000 12 inch 0.012 7.22 364.50 361.35 368.00 364.25 P-6 1-6 1-5 0.38 0.58 0.22 0.61 3.00 1.83 82.00 0.010366 12 inch 0.012 3.93 361.35 360.50 364.25 365.40 P-5 1-5 J-1 0.38 0.58 0.22 0.83 2.95 2.46 85.00 0.001176 60 inch 0.012 96.77 359.85 359.75 365.40 367.00 P-4 1-4 1-3 0.06 0.90 0.05 0.05 3.19 0.17 184.00 0.026087 12 inch 0.012 6.23 368.50 363.70 372.20 367.20 P-3 1-3 J-2 0.10 0.90 0.09 0.14 2.86 0.42 59.00 0.010169 12 inch 0.012 3.89 363.70 363.10 367.20 366.40 P-2 J-2 J-1 N/A N/A N/A 0.14 2.81 0.41 50.00 0.001000 60 inch 0.012 89.22 359.80 359.75 366.40 367.00 P-1 J-1 Outlet N/A N/A N/A 0.97 2.36 2.31 24.001 0.037500 12 inch 0.012 7,471 359.751 358.851 367,001 366.75 Epp -Y6/4P- C,PLGttLpa67i CIS t 0 Project Title:TIERSMA Project Engineer: Mounir Touma c:\haestad\stmc\tiersma.stm Touma Engineers StormCAD v1.0 12/O5/00 09:05:10 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Page 1 of 1 w VI . SPECIAL REPORTS AND STUDIES BIO-FILTRATION : We have accommodated the bio-filtration action within the wetpond as designed above in the Detention/Retention section of this report . Pg. - 31 VII . BASIN AND COMMUNITY PLANNING ACAS Pg . - 32 w VIII . OTHER PERMITS Pg . - 33 w w IX. EROSION/SEDIMENTATION CONTROL DESIGN The temporary erosion plan will be designed to reduce the chances that any construction related silty runoff will leave the site and affect downstream facilities . The amount of cleared area for road construction will be similar to the 2-year developed hydrograph. The peak flow for the temporary erosion sediment trap is 0 . 46cfs . From page 5. 4 . 5 . 1-1 of the KCSWDM a sediment trap should contain a minimum surface area at about 3 . 5 ' deep to allow settling of the particles . This surface area should be based on the formula; SA = FS (WVg) where FS = safety factor = 2 . 0 Q2 = peak 2-year developed flow V2 = particle settling velocity = 0 . 00096 f/s SA = (2) (0 . 43) / (0 . 00096) = 958 sf required Sediment Trap Dimensions 25' x 40' = 1000 SF at overflow 3 . 50' deep 19' X 34' at 2 . 5' deep 13' x 28' at 1 . 5' deep 7' x 22' at 0 . 5' deep 4' x 19' at the bottom The sediment trap should be constructed at the low area of the site, which is about the lot line between lots 11 and 12 . Pg. - 34 X. BOND QUANTITIES Pg. - 35 • M XI . MAINTENACE AND OPERATIONS MANUAL Pg. - 36 r � y XII . APPENDIX Pg. - 37