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HomeMy WebLinkAboutSDP200900020 Calculations 2009-03-20Tabor Cllurcli 3tion-nAvdttA- Nlarren Narrative County of Alben Virginia McKEECARSON I H iHr r ir F rk)ducholl Pr cc r1 pi it )f 1 nIn 1 )rclino,(4 Pre-De \ t-I)uvelopnicilt I dogy 1N'I'ROI)LJC TI()t 1 II: 1 abOr dtt2 iil !iic(;_i'illt'iit faCi}It`, (d rain ; }drder(f i di' i1,il(_'(. tt(c'.)ll }i;ei ll t t\ dill 1 iilit\ of 1'l:!li )f I. 1 \c;!ii garde,) i ., - ` -1 giit li `.t lil 71 ),x)._ess runoff (iii 1 post Lle\ eltfpillent Conditi t(1 precl:'\ _'l(epllic'rlt peat :: imp (ft rates. Pain !rdrl}('1.1 !s ,ll tt -lt" I Ili_tl ft! treat 0.5 inch cif first Hush from the iniper \ i(tus areas ()t proposed development. i llt' Nlochtlt'J the dl. t Virginia and _ (illi \' of ;\ 1`•'illdl l ) lc) usedRationalMethod (t'i't (lilinc'hlt -'cf b\. both stale t, \'' for hydrologic anal\ Sis. PROJECT DESCRIPTION 1-he labor htu'ch site is located in count\ Ot Albemarle. The nropert\ is locdt.ed on td nidp parcel numbers 1 i\1P 56A2- 1 -1_-I, - 12. Tile property is toned as Residential, 1_Do \\'nto \\'rl Crotct District. In the existing conditions, the propertv has t\V() existing building, d gravel dri\'e\\dv dnd d sma11 gravel parking lot. I he proposed de\'elc)pmcnt is an addition to the c\istin ; buildings a and un)dificdtion of the e\istinw, gravel dri\'e\\'ay METHODOLOGY Pre - Development Hydrology 1 hc' tOtal drainage area (including oft -Site area) for i abor Church site is approx. 1.703 acres and majorit\' of the site is draining to\\'ards the \\est boundar\ of the propert\' in form of sheet flo\\'. I he ? -\'r and i0 -vr predevelopment runoff from the site is approx. 2.95 cts and 3.87 cis respectively. Post - Development Hydrology In the post development conditions, the I door Church site is divided into t\Vo sub drains <_Te areas. l he first drainage aced (captured runoff) Consists of a portion of the proposed building addition arid the proposed drivc\va\'. The runott from first drainage area is flowing into the Rain Garden. I'hc second drainage consists of e \istin_T building, d portion of proposed building, driveway dnd open spaces; and remains imcaptured. - I - he required \\'a ter quality credit for till' proposed development is achieved throu;;11 rain garden and impervious diva disconnection sheet How over grassed areas). Sub I)rainage Area 1 (Rain Garden) The post- developn1cnt drainage area of appro \. 0. )1n acre is fio\\'ing in to the rr.iill .!,/1 Rill 1. 1 his Uh- dl'cl illage drei C01151515 Ot a portion of proposed build!ny addition and pr( post'(1 (Ari\'e\\'ay. l tt' 2 - \'r and If) )) \ 1' rullott from 1 1 <.lydt'n is pit11 "( 0.6 8 ('t`- and 0.05 it` respt`l ti \'el\ . l h(' r(tin is tii %ell t(! twit 0.5 inch (tf th(_' Iirst tli;sil li'011l a portion Ot pl'(Ipttticd blhidill!" root. I to bed area ()I rani garden is approx. 310 sl and ,ll>le I)) treat approx. 170 CI) (1 fir4 flush, 1111 - -o traind9e . \r(x.l 2 (ttnc'aptured RtutnoSt) 1 FR' i'.`- ill, l ;'ir1Til'li i1,nfi ge rca (>1 apprlo \. i.1, ) Jo 1-( ilill'ckl_%tnrcd. 1111.`;',ui. d af±,. -ttei 7111' ! l-'olk(k,ts tir i t)1t11`-,k of a portion of proposed buiiJi w and ,il`i\'e \ \'d \' chid 11pcn sl- (il_'i `-,. 1lle 1 11`, 1" 'i ti A n 'jam r 2 C)' t- ti' - r 11Milt, -i { l i -\ i i1.1;1t e I i i I' U i tl'i lli_,l` c t'a i` ti [Trot. ...,d. il' 1; id r. ,... t,,4' SUMMARY In tit(' pest ile\ e'lt,t)nll'lit l(uidititfil approx. 2,07t) sf lrI impt`r\ i U , area i added to the site. 11 additional irnper\ ions area reduires treating approx. 87 (.7t (Il.) inch Ot added impervious drew) of fiat flush. l he rain garden is sired to treat appro\. 17U ct of fiat flush. Also, the fiat tlt-lsll from a portion cif proposec.i building, is tlliwing over the grassed area \\`hicl \vi11 help to achieve tiunle additional \\ yo ilit \ credit. Following is the stm Indry of pre -developn ilt and post - de\ hydrology c,t Tabor Church site: Area Including; I 2 -Yr 1O -Yr Ronoft 10(1 -Yr Runt01 ott- -site Drainage , \rea) Runoft cre)CIS)ctti)ts) Predevelopment 1.795 2.95 3.87 5.07 Post development Rain Garden 0.68 1.05 130 r \rea =0.5 1 h Uncapt. Area = 1.270 02 8; Total Area = 1.795 2.91 3.87 5.13 Td bor Ch u rch M ii Ai., •••.........„ of .-- --- ...._ _ W V r = .:... , 1 t 1 : 1, - .;, 1 77 1 t. 7 I - n I 1 1 7t) --"::- 11 11111 111• 711••• K.'.... --,,, Z.- t ra 0 1 11\44, i 1 1 1111 771 4 • . " i 0 M la n k..., ....... FR E Co 4 V) i Vi 1 ° U R c• LI U A , r 73 i il 4 4 ,.. ‘ 0 71 XI 0 w 0 4/ 0 1..4 Z- 1 37 I 1 I 73 I 1 414111111414118144% 410444. M 7 7 — 7 11 t i 71 I* 4414t81111444 7, .. ) „... 1 a I t C_) CD 6 Z 11 Co ` C ca n 4 it,. na rt i..... n o rttl > rt (,)t tia (') 4 4 rt- TABOR CHURCH C) PFi HI- 4 1ri. ,, :,F 71 77 t. tr' : rri I N 14 AV i 7 ' 4 4 , rn 4 _.... ..„.1- 1 73 7 1 n. I , r p — 4 1 - 4 — (:),, > 7 FT, 3,,,, n _.--, r- r1 1 1 er t 1 1 i z _ 77 1- 7 7 n 0 _________ 0 0 0 n , --,, t!.. r› E> -- t,....) c - 0 n c c) if 7 1 44‘14. t , ) 0 C) m r, 1 7-, !--. ''' C : t,,,, .. t.--) " "\-) z 73 < rri A 0 I 4C) n m 71 7 411 ri t' n rt t . ...) Z n - 1 , - ..... 0 7 , m 7 r) r r l F R 0 C 0 tv r 1 44 0 rn VV 1,-) ' ' - ::::: : s ... e." 0 V u 3Z. 311 737 n 37 1 371 l ii4444,1 I1 I 1 o. I.... 0 ri 171 7 . ', T, Y i 41 11 i',. n (- e' r El INIIIN441111 ril H 1 414441. 4144 1 13 77 1 Z 0 r::' 0 0 Mt 33C' 0 0 F71 37 > r"' '" r• < C2). 21 0 11 it 0 3 c Is.,.) . Z r., 4 , 4 . cro 0 rr ' - ' `— r*** -... 1 t. 1 21 -, n an "" , ri ' 77 3 11 4,../ 1 () f.") tl TABOR CHURCH 0 1 h.) 1 Thbor Church Pre-Devclopment 1\ drcd(),,-2-,v Short Version EMP Conift.ih- it cir Worksheets : -1 lcif.,e,i -ilmilk-e Plan Tabor Church Vater Rice s Area i,.i.:i Preparer Bf ad. }1)C r 11r-v PUfet- Dralnac:ie Area Dr.sr.)i P L sIn pi,li e,purf n, pft wet. L =11)f PpPv,I2 ft C(Af2 ;le; Rv mean runoff coefffver 1 9v = 0 05 x fif 0294' Pj small storm correctton fact.e! 0 P 1 percent in iperv[ousness P annual precipitatign 4 A protect area in acres ni subje ct. dralnage area.A =1 80 C pollutant cencentratlos mg I cr pr.xm target phosphorus f factor applied to fftrt V requIreci treatment voIume [n , ey 0 5" over Impery area = NI )4356 0 5/12)/27 RR required removal Lii:osn - f x L(sref RR removal efficiency . RR100/Ltpost) Impervious Cover Computation (values in feet & square feet) Item pre-development Area post-development Area Roads Length Width subtotal Length Width suototal 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Driveways Length Width no subtotal Length Width no suototal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots/Roads Area 1 Area 2 Area 3 Area 4 Area 1 Area 2 Area 3 Area 4 0 0 0 0 2585 0 0 0 0 3621 Gravel areas Area 1 Area 2 subtota Area 1 Area 2 subtotal 0 0 5437 x 0 70 = 3805 9 0 0 5075 x 0 70 s 3552 5 Structures Area no btotal Area no subtotal 0 0 0 0 0 6633 0 0 766/ ActIvely-grazed pasture .E',Area Area yards and cultivated turf 63535 2 x 0 08 =5082 816 66902 2 x 0 08 =5352 176 Active crop land Area Area 0 x 0 25 -0 0 x 0 L5 =0 Other Impervious Areas Area 1 Area 2 Area 2,Area 1 Area 2 Area 0 0 0 0 0 0 0 0 Impervious Cover 23`k l(pre)l(post) Rv(post) V 023 41? New Development (For Development Areas, existing impervious cover <= 20%) C f I (pre) ' Rv(pre) L(pre) L(post) RR Vo RR Area Type 0 70 1 00 20',, 0 26 2 85 3 11 n 26 9'ff De velepmeni r',fE3 093 1 00 0Vr, ff) 26 1 ±12 1 '.7,0 13 9'v, Dt , rif , Ind \Nat : r late s1le .is 0 40 1 00 1 ff f_ 6 1 ee I 18 0 15 9V: ritHer PAIL Ife e nff values Redevelopment (For Development Areas, exiting impervious cover -> 20%) C f i (pre) ' Rv(pre) L(pre) L(post) RR A RR Area 3 ype 0 70 0 :10 20 V if nr-,pF,I 1 18ez 1- f! xemeift ALfa 0 f3 193'5 0 ; f lel 1.22v, ffr ler g'v"11ter , l/i-i , 2,.':, :")1Lf 1 rfn1 I le ,xl Company: McKee Carson Tab r.. hurcFt :: ; >.: Designer : Brajesh Tiwari Time cif_ Cc711C E1tiCatlOtl: :: Date 03/20/2009 I TIME OF CONCENTRATION (PRE QEVEL©PMENT} - -: ?: :::: -• Overland Flow Curie;::: Source: Seelye Chart as modified in VDOT Drainage Manual (Appendix 6D-1) l) Length of overland flow a /ways = 300 ft 2) Calculate ,; separate T0 for each ground covet condition ,)l.in0l the froly path 290.00 Enter Length of Strip (ft) 4.50 Enter Slope ( or ft /100ft) 0.35 Enter Rational Method "C" value 12.54 Result Tc (minutes) Shallow:Concentrafec :PEov, :Tirrte: `;::/ Source SCS Velocity Graph as published in Virginia Erosion and Sediment Control Handbook Third Edition Notes 1) Not intended for well - defined channels - see channel flow calculatron 2) Calculate a separate Tc for each ground covet condition along the flow path 0.00 Enter Length of Flow (ft) 4.10 Enter Slope ('' or ft /100ft) 0.66 Velocity (ftls) IF UNPAVED 0.83 Velocity (ftls) IF PAVED 0.00 Result Tc (minutes) IF UNPAVED L- -_ 0.00 Result Tc (minutes) IF PAVED Channel Flow:T3me Source Kirpich Chart as modified in VDOT Drainage Manual (Fig 1 5 1 2 on Page 1 -14) Notes. 1) For small drain , rde. basins 2) For concrete c roar - ls. use 0 2"Tc 0.00 Bottom (7 / dth (ft) 6.50 Side Slope (Left) 6.50 Side Slope (Right) 2.00 Height (ft) 26.00 Cross Sectional Area (ft "2) 26.31 Wetted Perimeter (ft) 0.99 Hydraulic Radios (ft) 0.04 1Channel lope 0 03 111,1anning 'iii F 9.35 Velocity (ft/sec) 0 00 Len;lth of 1 -1Hiu, (ttl 0.00 Result Tc (minutes) 12.54 min S Company: McKee Carson TOb.Of-ahU:rth::::.1::::-'..:'::::::::::::::::::::':::'::::-::::-::::::::::::.:: Designer: Brajesh Tiwari PredeVelp00 11 Date 03/11/2009 I • OREDEVELOPMENT:ONDEPPN:::::::::::::::::;::::::::.::::::2:::::::::1::::::?:::;-:::::: 1 TYPE TOTAL PERCENT C CA 8ulldings 6633 00 8 5cX-,0.90 5969 TO Grass & DIrt 63556 00 81 3',/,0 35 22244 60 Grav el 5437.00 7 0c 070 380591 Pa./ernent'Cencrete/Side//alk 2585 00 3 3P/k 090 2326 501 ------ - L-- 1.Ti 78211 00 2_ 1400 34346 70 , r Average C =0.44 1 : : -:::::::::- : :::::": :1 -- " -- : Tco-o-rAL)(Assumed)=I 12.54 mins I Return Enter Intensity Period Duration Intensity (b/(d+Tc)"e e b d 2 10.6 3 7 0.82 49.02 10 5 5 106 10 106 49 0.73 46 95 95 25 106 50 10.6 100 10.6 64 055 31 09 5 4ccept,t)le valty_?.s fot dinatiun are betv,een 5 atici 60 mitaites Use values outsIde thls range at risk Peak Discharge Q =CIA C=1--ili 44 7 1 i H A =1 ;12-i: 1,-, i r 2-Yr Peak Discharge Q2 =2.95 Os 1i Iir1i10-YrPeakDischargeQ-387 Ids I 100-Yr Peak Discharge Q10 5.07 I IdS i TA Chu rch Post-Development _Hydro-10;4,v Company: McKee Carson abor ht PG ..:::_; Designer : Brajesh Tiwari T(f11 of: GbtnCentt`atIi3C: : : : : : . :: Date 03/20/2009 IME:Of :CONCENTRATION ( POSt= DEVELOPMENt.UNCAPTUR.ED):: Source. Seelye Chart as modified in VDOT Drainage Manual (Appendix 6D-1i Notes 1) Length of ovehand tl s v orl;vays 300 0 2) Calculate a sepr;roite To for each ground cover condition along the flow path 290.00 Enter Length of Strip (ft) 4.50 Enter Slope ( or ft /100ft) 0.35 Enter Rational Method "C" value 12.54 Result Tc (minutes) ShaJlOW Co icenfrated Ftoiv:("lime := Source. SCS Velocity Graph as published in Virginia Erosion and Sediment Control Handbook, Third Edition Notes. 1) Not intended for well- clef-necl channels - see channel flow calculation 2) Calculate a separate Tc for each ground cover condition along the flow path 0.00 Enter Length of Flow (ft) 4.10 Enter Slope (° or ft /100ft) 0.66 Velocity (ft/s) IF UNPAVED 0.83 Velocity (ft/s) IF PAVED 0.00 Result Tc (minutes) IF UNPAVED 0.00 Result Tc (minutes) IF PAVED Source Kirpich Chart as modified in VDOT Drainage Manual (Fig 1 5 1 2 on Page 1 -14) Notes. 1) For small dl ait iage hasins. 2) For concrete channels use 0 2 Tc 0.00 Bottom Width (ft) 6.50 Side Slope (Left) 6.50 Side Slope (Right) 2.00 Fle!ght (ft) 26.00 Cross Sectional Area (ft ^2) 26.31 Wetted Perimeter (ft) 0.99 Hydraulic Radius (ft) 0.04 IChannei Slope 0.03 Manning 'n' 9.35 Velocity (ft/sec) 0.00 ngth cif Flow (ft) 0.00 iResu!t Tc (minutes) To, , eii i , -12.04 rains Company: McKee Carson Tab' r CbUIrt :::1 Designer : Brajesh Tiwari P Uncaptured Rtinoff:from: :thy .Sit :: : ; :: 1 Date 03/11/2009 PREDEVELOPMENT' ::;:- ::::: 2:22:2:::: :: :: < : :: : : : : ::: : < = _ . TYPE TOTAL PERCENT C CA Buildings 6067 00 10 9` -F,0.90 5460 30 _ Grass f_, Dirt 42986 00 77 1 1' :0.35 15045 10 r Gravel 3052.00 5 5' 0.70 2136 401BsivementiSidetivll.. 3621 00 6 5C 0 90 3258 90 7 517729, rctai00100 00070 r Average C =0.46 j TIME :OF - .CONCENTRATION PRE :DEVELOPMENT):: : : : : : :: 2: :00: : 2::: TciTCT Assumed) =12.54 mins RAINFA4VINT- ENMITY ::2222.. Return Enter Intensity Period Duration Intensity (b!(d +Tc) ^e e b d 2 10 3 082 49.02 105 5 10.6 10 106 49 073 46.95 9.5 25 106 _ 50 10 6 100 106 64 055 31.09 5 5/ ble values fnr blunirron ate between 5 , rind bu niuiute:-; Use values ,a-1tsicle. tills range at risk PREDEVELOPMEt T.PEAK DES :CHARD:E: : : :: Peak Discharge Q =CIA C i 1111 iii , l - -- 1111 1 - - - -- 1111- --- - -- - A =T 279 L 1111 -- 1111 -- E re, 2-Yr Peak Discharge Q- = T - - -- 1111- 2.23 cis 1111 -- 1111 1 --- 1 -- 1111- 1111 -I90 -Yr Peak Discharge Cif) 2.92 Cfs 100 -Yr Peakak Discharc ti ? 1111 -- 1111 -- Company: McKee Carson T bOr Designer : Brajesh Tiwari Time oft : Date 03/20/2009 v_ erland Flow Tiitie_ Source Seelye Chart as modified in VDOT Drainage Manual (Appendix 13D-1i Notes 1) Letigth _ oueti, ;nd flow always 300 0 C,)h.ulaie sc f>aiute Tc nu each gr0ttnd Lover condition along the flow path 250.00 Enter Length of Strip (ft) 6.00 Enter Slope (;., or ft /100ft) 0 35 Enter Rational Method "C' value 11.15 Result Tc (minutes) Shai.low. Concentrated:F'1ow ;Tltne ::::':: :::;::: Source SCS Velocity Graph as published in Virginia Erosion and Sediment Control Handbook. Third Edition Notes 1) Not intended for well-defined channels - see channel flow calculation 2) Calculate o separate Tc for each ground cover condition along the flow path 0.00 Enter Length of Flow (ft) 4.10 Enter Slope (''-: or ft /100ft) 0.66 Velocity (ftts) IF UNPAVED 0.83 Velocity (ftis) IF PAVED 0.00 Result Tc (minutes) IF UNPAVED 0.00 iResult Tc (minutes) IF PAVED Channet:Ftow:Tin e Source. Kirpirh Chart as modified in VDOT Drainage Manual (Fig 1 5.1 2 on Page 1 -14) Notes f of :good/ (tramo(te t )asuts 2) For concrete channels. tit 0 2'7 0 00 Bottom Width (ft) 6.50 Sidi- Slope 6.50 Side Slope (Right) 2 00 Height (ft) 26.00 Cross Sectional Area (ft"2) 26.31 Wetted Perimeter (ft) 0.99 Hydraulic Radius (ft) 0.04 41x;1 ,eI ,!ot.e 0.03 Paann;i;r; 9.35 Velocity (ft /sec) 0 00 Length of Flnvi ,ft 0.00 Result Tc (tniriutes) 1 `. r ; r.i -1 1 . " ,i 111115 Company: McKee Carson T11btit:ChhurGh.;` :1 - : : : .2 .: :: 1 Designer: Brajesh Tiwari Postdevetopment unoff -j RatC :Gatdei _ :::: : : : : -.I Date 03/20/2009 PREDEVELOPMENT :COND1TIQNS : ::: : :;I TYPE TOTAL PERCENT C CA Buildings 1600 00 7 1 °r.0.90 1440 00 Grass & Dirt 18412 00 31 9%0.35 6444 20 Rain Garden 450 00 2.0 %4 0 20 90.00 Gravel 2023.00 9 Cr.0 90 1820 70 Total 22 00 100 0';9794 90 C—Average C =L 0.44 TIME :QF: :CONCENTRAT #ON ::{PRE::: EVEL - «PM :NT:= : :: :_ :.: >: _ :_ :: ::: : :: : :: : : : ::: : : : :: :: : : :: TciTOlAL) (Assumed) =11.15 mins tV :A 4 T NgtT t : : : + : : :?; ::": i ?a- :: -:: - : :: : : :: Return Enter Intensity Period Duration Intensity (b /(d +Tc)^e e h d 2 5.0 39 0.82 4902 105 5 50 10 5.0 5 1 0 73 46 95 9 5 25 5.0 50 5.0 i 100 5 0 6 7 0 55 31 09 5 4(,, ehtal}le values for duration are het en 5 rind 60 minutes Use values outside this range at nsk PREP. V CRAW4T Pt kK:371S - GE:::::::;::::::: ::::.:::::: .. :::::,': := Peak Discharge Q =CIA C 1 11 1 1 51C, Yr ions p INPUT: E, Rain (,,rd M contour Areas Elevation(ft)aa.rea(sf) Computed vol . (cy) 704.00 310.00 0.0 704.50 150.00 7.0 705.00 610.00 16.8 1 Outlet Structures Outlet structure 0 weir name: 10 vr length (ft)1.200 coefficient 3.300 invert (ft)704.500 multiple 1 discharge through dam 1 inflow Hydrographs Hydrograph 0 Modified_Rational name: 10 -Yr C 0.440 Area (acres)0.520 IDF file: a2 time of concentration (min)11.15 receding factor 1.670 time increment 0.10 time limit (min)1000.00 fudge factor 1.00 storm: crlt. duration (141 iterations) volume (cy)33.98 peak flow (cfs)0.746 intensity (in /hr)3.260 time to peak (min)11.150 duration of peak (min)5.61 routed true OUTPUT: Routing method: direct Hydrograph 0 Routing Summary of Peaks: 10 - Yr inflow (cfs)0.747 at 11.20 (min) discharge (cfs)0.681 at 18.110 (min) eater level ft)704.809 at 18.:0 (min) storage (cy)12.541 Fri mar 20 12:21 :.3; 5 EOi :009 a pr lrltUut NPUi: U:?.in: Rain Gar! :en Contour ,Areas E 1 evat i on(ft)4rea( sf) Computed vo ! . (cy) 704.00 310.00 0.0 704.50 450.00 7.0 705.00 610.00 16.8 1 outlet Structures Outlet structure 0 Weir name: 10 yr length (ft)1.200 coefficient 3.300 invert (ft)704.500 multiple 1 discharge through dam 1 inflow Hydrographs Hydrograph 0 Modi fi ed___Rati onal name: 10 -Yr C 0.440 Area (acres)0.520 IDF file: a1.0 time of concentration (min)11.15 receding factor 1.670 time increment 0.10 time l i m i t (min)1000.00 fudge factor 1.00 storm: cr duration (141 iterations) volume (cy)42.23 peak flow (cfs)1.073 intensity (in /hr)4.689 time to peak (min)11.150 duration of peak (min)2.83 routed true OUTPUT: Routing Method: direct Hydrograph 0 Routing Summary of Peaks: 10 -Yr inflow (cfs)1.074 at 11.20 (min) discharge (cis)0.952 at 15.90 (min) water level ft)704.887 at 15.90 (min) storage (cy)14.081 Fri Mar 10 16:77:26 LDT 2009 i ,i ;r 100 BasinFIo'd or!ntout INPUT: Basin: Rain Garden 3 Contour Areas Flevation(ft)area(sf) Computed Vol.(cy) 704.00 310.00 0.0 704.50 450.00 7.0 705.00 610.00 16.8 1 Outlet Structures Outlet structure 0 Weir name: 10 yr length (ft)1.200 coefficient 3.300 invert (ft)704.500 multiple 1 discharge through darn 1 Inflow Hydrographs Hydrograph 0 Modified_Rational name: 10 -Yr C 0.440 Area (acres)0.520 IDF file: a100 time of concentration (min)11.15 receding factor 1.670 time increment 0.10 time limit (min)1000.00 fudge factor 1.00 storm: crit. duration (140 iterations) volume (cy)55.54 peak flow (cfs)1.408 intensity (in /hr)6.153 time to peak (min)11.150 duration of peak (min)2.87 routed true OUTPUT: Routing Method: direct Hydrograph 0 Routing Summary of Peaks: 10 -Yr inflow (cfs)1.409 at 11..20 (min) discharge (cfs)1.289 at 15.40 (min) water level (ft)704.973 at 15.50 (min) storage (cy)15.887 Fri Mar 20 12:20:34 EDT 2009 P, . Company: McKee Carson Designer: Brajesh Tiwari Date: 03/20/09 DRA[NAGE ARE/4 DATR 1 Faalitre-s Drainage Area =T 0 52 2vrres 1 IAdded Impervious Area on Site I 2070 00 f Impery Area to Ram Garden=l 1000 00 Isf Water Quality Volume Require 1 rVd_u=86 25 k1 r0 5 First Push Biofilters Treatment Required 86.25 Icf - I Filter Bed De•th (df) _I 2 50 Jft 5 -4 ft; Filter bed Eievat,on =i 1 00 Ifl_ - Ma >rmum Pending Deuth =J 0 25 1 mar Permeability Coefficient ;k r =1 1 00 I t /day Design Drainage Hine t = 0 50 day Average Desian Pnndina depth (davqf = 0 25 Ift Remuval Rate =11 50 00 Required Fr ter Bed Area (Aav ) -I 156 82 Is( Provded Filter Bed Area =1 310 00 L Provided Infiltration Volume I 170.50 Id