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WPO201800078 Calculations 2020-10-26 (2)
Keswick Hall Spa wPO 201800078 COUNTY OF ALBEMARLE, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE OCTOBER 26, 2020 f TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Ave, Suite 200 Charlottesville, VA 22903 434.327.1688 L CRATG W. J. KOTARSKI Lic. No. 0402048507 APPROVED by the Albemarle County Community Development Department Date 11/18/2020 File WPO2018000781 Amendment #2 Table of Contents Section Title Project Narrative 2 Pipe and Inlet Computations Virginia Runoff Reduction Method Worksheet Summary 4 Pre -Developed HydroCAD Calculations Post -Developed HydroCAD Calculations 6 Nutrient Credit Availability Letter Project Narrative: This project includes the demolition of an existing parking spaces and garden area, construction of a spa facility, parking and associated utilities. Erosion & Sediment Control Limits of Disturbance is 2.60. An area of 2.02 acres was used for water quality and quantity calculations. Water Quality Compliance: The disturbed area of 2.02 acres was used for the water quality analysis. In the proposed condition there will be 0.94 acres of managed turf, 1.08 acres of impervious cover. Approximately 0.55 lb/yr of phosphorus shall be removed through the installation of permeable pavement. A total of 1.09 lb/yr have been previously purchased. This plan now proposes an excess water quality treatment of 0.13 lb/yr. Water Quantity Compliance: Stormwater Quantity requirements for analysis point 1 will utilize a CMP detention system located within the parking area to meet all stormwater quantity requirements for this drainage area. Energy balance and channel protection for this analysis point are in compliance with all requirements. FORM M 201 STORMWATER INLET COMPUTATIONS SHEET 1 OF ROUTE CMNOMe PROJECT Kesaick Hall Spa OESIGRER: CG DATE 1011912020 CHECKED: UNTTS:NGUSH ��m�mmm0000mmmmmmmmmmmmmmmmmmmmm��mm• mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomommmmm�mommmmmmmmmmmmm��m mmm�mmmmmmmmmmm®mmmmmmmm®mmmm®mm�®mom ®�m�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmomommmmm�mommmmmmmmmmmmm��mm• mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmmmmmmm®omommmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm�mtm� mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmm®�®ommmmmmmmmmmmm��mm• mmmm■®®mmmmmmmmmmmmmmmmmmmmmmmmmm��mm mmmm■mmmmommmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm�mtm� mmmm■mm�mmmmmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mm®mmmmmmmmmmommmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmm®mmm®mmmmmmmm®mm®mmmm�mtm� mmmm■m®®mmmmmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mmmo®mmmmm®®®mmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm�mtm� ®mmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mm®ommmmmm®mmommmmmmmmmmmmm��m mmmm■mmmmommmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmmm�mtm� ®®mm■m®®mmmmmmmmmmmmmmmmmmmmmmmmm��mm� mmm�mmmmommmmmm®�®mmmmm®m®mm®mmm��mm� ®mmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmomommmmmmmmmmmmmmmmmmmmm��m� mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mmmomommmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmmmm®m®mm�mtm� �®mm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mmmmmmmmmmmmmommmmmmmmmmmmm��mm• mmmm■mmmmomommmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmmommmmmmm�mtm� mmmm■mmmmommmmmmmmmmmmmmmmmmmmmmm��mm• mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmmm■mmmmo®mmmmmmm®ommmmmmmmmmmmm��m mmmm■mmmmmmmmmmmmmmmmmmmm®mmmm®mm�®mom ®®mm■mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m INLETSOFT BY ENSOFTEC DATE: IO18=0 FORM M 204 STORMWATER INLET COMPUTATIONS SHEET 2 OF 2 ROUTE CMN OMe PROJECT Kesaick HO Spa OESIGRER: CG DATE 10/1912020 CHECKED: UNITS:NGUSH INLET Sa Inkis Onl BE 0021 6542 0.13J 0 061W 00208 1In 2" 14577 00833 4.0048 350 BrF/L1. 0 6542 0 0 AMsd/W. 0.137 00100 1" 1 0137 08W 0165IM3414 3240 W—Fl- 134 a fo-0 0 6 0 0 Bwk/L1. 045 0016 AMSNRI. 0018 4 0022 0 OWI 00208 16N1 20'.q 12048 00833 4W48 350 AMSNRI. 00'R OWI 06M 067 0012 OT45 01652983 We,,Fl— INLETSOFT BY ENSOFTEC DATE: IO 18=0 LO-229 PROJECT: Keswick Hall Spa STORM SEWER DESIGN COMPUTATIONS LOCATION: Charlottesville COUNTY: Chadottesville STORM FREQUENCY 10 NOAA STATION: Oesignecl by: CG Checked by: UNITS ENGLISH PIPE NO. FROM POINT TOmm DRAIN, AREA 'A' Acre S 2DNOFF COEFF C. 4 CA TOTAL INLET TIME MmNR ] RAM FALL INHr H RUNOFF INVERT ELEVATIONS LENGTH of Pipe Ft 12 SLOPE FtN 13 SIZE (EN Or SpeolO.) Io 14 SHAPE Nwnber ofh,e CVWiD, CFS IS Friction Slope Fla NOkMAL FLOW FLOW TIME Sec, 17 REMARKS 18 INCRE-ACCUM- MENT 5 ULATED 6 L.N CH Total CFS 9 UPPER ENO 10 Wg ENO 11 "PO' of Flow,M Ft Areaof FIow, Ao SgFt Hm Ft V. Fd$ 16 On Ft REFERENCE 1 STA. REFERENCE 2 STA. 101 102 100 0DO 0DO 020 56f 634 0OD 1123 41223 4H70 5302 001" u C-ul. 1 2451 0MUD 095 107 048 763 1M 695 103 104 102 0DO 0DO 020 537 662 aOD 1123 41350 41233 116M 001W4 ]A C4ud. 1 2267 000260 IDO 156 050 7,20 IW 16.19 105 106 1" 025 049 D.12 020 529 665 OW 1123 41397 4130 36.95 00ID01 2A Circular 1 2452 000UD 095 147 D48 763 1M 4.M 107 108 106 0DO 0DO 005 5.14 650 DOD 10,32 41696 41407 17n 005006 18 Circular 1 23" 00D660 067 076 035 1365 3% 423 107A IOSA 108 007 O.W D05 005 5W 654 OW 036 42463 424.3] 25.65 001014 12 Circular 1 389 OOWD 020 0.12 0.12 309 035 $31 IN $WM3 OUT 108 ON ON ON 500 ON O00 1 997 42200 42032 5593 003004 18 Cuodfl 1 1972 DOOM 076 089 038 11.19 270 5W 113 114 112 0.15 0]] 0.12 0.12 SW 654 OW 076 421 IN 4200 900 001" 12 Circular 1 3.86 00W40 030 020 0.p 382 053 2M 11$ 116 $WM3 D'1 039 OW 024 OTt 5.19 6/8 O00 205 42363 423.16 2]00 OOIW] 12 CireWar 1 386 OpOJ(q 052 041 026 499 091 541 115A 116A 116 ON 098 008 008 5W 654 OW 053 42392 42353 3903 0W999 12 Circular 1 386 00W20 025 0.is 0.15 345 0" 1132 Ip 118 $WM3 QJ 026 052 0.14 061 563 634 O00 389 42327 42241 8568 001W4 18 C4 ud. 1 11M 000120 ON 067 032 584 1.13 1467 119 120 Ila D51 D39 ON 042 J51 638 OW 269 423]4 4233] 3205 0_W939 18 Cnvul. 1 113] 0DAN 050 051 D28 527 093 7O3 121 122 120 026 047 0.12 0.16 528 665 0OD 1DO 42598 4BM ]953 00201 15 C-ul. 1 Dp8 0W20 026 0.is 0.15 5.84 079 1363 123 124 122 008 051 0A 004 5W 654 DOD 02] 423,19 42608 ]0.30 003MI 12 C-War 1 669 O00010 0.14 ON ON 4.16 041 16% 125 126 120 0.10 OW OM ON 5W 654 000 039 42388 423M 398 001005 12 Circular 1 38] 000010 022 0.12 0.13 3.1] 037 126 127 128 118 ON 0.32 002 002 5DO 654 200 0.12 42402 423.71 3121 0W993 12 Circular 1 385 OOCWO 0.12 0W 008 225 020 13M 129 130 118 00] 09 0A ON 5W 654 0O0 023 425 DO 424.94 404 0014M 12 Ci¢War 1 4]1 DOWN 0.15 007 ON 3.11 OM IM 131 132 106 003 0]0 002 002 5W 654 DOD 0.14 414,13 4139] 3125 0W512 15 Circular 1 501 Oq,WO 0.14 008 01N 178 0.19 253 133 Jim 106 0M 045 0D2 002 5W 654 000 0.12 41433 414.13 1986 00IM7 8 CireWar 1 1.31 O= 0.14 005 008 2.35 022 84] LD-347 PROJECT: Keswick Han Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: 10 Year INLET OR JUNCTION STA INVERT EL OUTFLOW PIPE DEPTH OFI'. OUIFLVN PIPE DR. WATER SURFACE ELEV. DN. PIPE Do I DESIGN DISCH. Do CFSCMS IENGIR PIPE In MILTON SLOPE, Sb ("D FRICTON LO55T-CE., XI F.FNA JUNCTION LOSS SURFACE FLOW Mf. NI 13 HI Inlet INN TCpMMX SNaplry9 OS FINAL WNer Top MlntA M�¢V�IR M H Svla¢ Elev. YMVM EIGwJN, S.P. Yi Uf]llg III(Fapn) OSS'MAX. SKEW S,. K BeM X 5m HL FLM (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (16) (17) (18) (19) 100 413.290 102 411.7D0 2.00 413.300 24 11.232 53.02 0.00220 0.116 7.631 0.226 7.199 0.805 0.282 0.0 O.OD 0.000 0.508 OODO 0.508 YES 0.254 0.370 413.670 420.930 O.K. 104 412.330 2.00 413.930 24 11.232 116.56 0.00258 0.300 7.199 (1201 7.634 0.905 0.317 0.0 OM 0.000 0.518 URI) 0.518 YES 0.259 0.559 414.495 418.490 O.K. 106 413.600 2.00 415.200 24 11.232 36.M 0.00220 0.081 7.634 0.226 13SM 2.895 1.013 0.0 0.00 DA00 1.239 0.787 1.239 YES 0.620 0.701 41SM1 418.750 O.K. 132 413.970 1.25 415.901 15 0.137 31.25 OGDOOD 0.000 1.783 0.012 D.000 0.000 0.000 0.0 0.00 0.000 0.012 0A37 0.016 YES 0.008 UM 415.909 416.750 O.K. 134 414AW 0.67 415.901 8 0.118 19.86 0.00008 0.002 2.345 0.021 0.000 0.000 0.000 0.0 0.00 0.000 0.021 DAIS 0.028 NO 0.028 0A29 415.00 417.680 O.K. 108 414.070 1.50 415.901 18 10.321 57.73 0.00860 OAM 13.654 0.724 11A91 1.945 0.681 0.0 MOD DA00 1.404 0.000 1.404 YES 0.702 1.199 417.625 428.290 O.K. 108A 424.370 1.00 425.170 12 0.356 25.0 OGDOD9 O.D02 3.088 0.037 0.MO 0.000 0.000 0.0 0.00 0.000 0.037 0.000 RM7 YES 0.019 0.021 425.191 429JM O.K. SWM3 OUT 420.320 1.50 421.520 18 9.970 55.0 0.00802 0.449 11.191 0AM 0.000 0.000 0.000 0.0 0.00 0.000 0.488 URI] 0.486 YES 0.243 0.692 422.755 427.000 O.K. LD-M1 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Che&k INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION STA. INVERT EL. WT M PIPE DEPTH OFFLOW OIRFLOW PIPE WTLET WATER SURFACE Ej , DIA PIPE D. I. DESIGN DISCH. Go CFMMS LENGTH PIPE jn F FRICTION SLOPE, Flu ("am MM FRICTION LOSS w FW JUNCTION LOSS SURFACE FLOW mjj. It laShaliig9 R FjRA h. YM 05 R FjRA FINPL H FW INN Wajc Su - EIR aa.n TpMMH Tep HINH El - APPROX. AtljWncMY Vo Cmtr. Ib F. Yi V�'9ag Hi (Eryn) 0Wmm, SKEW Angle K Pad H FLM Sum HL PRM (1) (2) (3) (4) (5) (6) (n (8) (9) (10) (11) (12) (13) (14) (15) (16) (16) (17) (18) (19) SWM3 IN 426.000 148 422.410 1.50 426.000 18 3.890 85.68 O.W122 DADS 5.841 0.132 5.270 0.431 0.151 0.0 0.00 0.000 0.283 0.856 0.368 YES SAM 0.289 426.289 428.200 O.K. 120 423.370 1.50 426.289 18 2.692 37.05 0.00058 0.022 5.2]0 0.108 5.837 0.529 0.185 0.0 0.00 0.000 0.293 1.269 0.381 YES SAW 0.212 426.501 428.300 O.K. 122 423.840 1.25 428.501 15 1.055 79.53 0.1�4 0019 5.837 0.132 4.180 0269 0.094 0.0 OM 0.000 0.226 0]8] 0.294 YES 0.147 0.188 428.667 430.260 O.K. 124 428.OW 1.W 428.880 12 0.288 5 0000 4.iW 0.06] 0.000 0.000 0.000 0.0 OM O.WO O.W] 0.288 0.087 YES 0.044 0.047 428.327 032.720 O.K. 116 423.160 1.W 426.000 12 2.053 96 0.080 4.992 0.097 3.448 0.185 0.065 0.0 OM 0.000 0.161 1.523 0.210 YES OA05 OA85 426.185 430.140 O.K. 116A 423.530 1.W 426.185 12 0.530 20 DOOR 3.448 0.046 0.000 0.000 0.000 0.0 OM O.WO 0.046 0.530 O.WO YES 0.030 0.038 426.222 428.010 O.K. 128 423.710 1.W 426.289 12 0.124 01 13t210.0DO01 D000 2.251 0.020 0.000 0.000 0.000 0.0 O.W O.000 0.020 0.124 0.026 YES 0.013 0.013 426.302 428.550 O.K.9 12 0.229 04 0.000 3.iW 0.03] 0.000 0.000 0.000 0.00.00 0.WO 0.03] 0.229 0.049 VES 0.024 0.02d 426.313 428.090 O.K. 126 423.840 1.W 426.501 12 0.393 11 0.000 3.170 0.039 0.000 0.000 1 0.000 1 0.0 0.00 0.000 0.039 0.393 0.051 YES 0.025 0.026 426.SP7 428.070 O.K. Vm)ed Cr ¢ tnnen<vdume and load:) Eme, TWInisWld Isa .v,�aam�a�,wea�„m�wvn I Lm , .m,a.om�.n—d�,O mano..."onto ma—�oeadonm mea„ Drainage Area A Draroage Area Aldan corer d[rep ., nm Stormwater Best Management Practices (RR= Runoff Reduction) Total Pbo[pbor-Mallable Nr Remonl In 0 A.AIIb/yri n.t] Port Dewlopm MTremm nt VolumeInDAAIMI 2]6 -SNettfromaroPdownIlm- Prams[. Runoff ReEb uttn .R % ManyeG Impen'bu[ Td.. C.- Credit Area a[ Area a[ Volume team RunuH intention Reduction i. pmalre lava ing RunoNVolume Total side TeatlneM Volume Phod,d 5 Rem. CMden % manWhorus Wad Unmanned from Uprtream PboIbmu[load Pars.- a Ib bPractl[e Iftil PM1ospbmao Remained R, Pmttice Ib Remaining P.,ha-Wits Ib Daandemmm Mamlee to be Cmplaim. a.'im-tea We., ea asl e. vagnaae Roof xx Iscea asl to same oxamnmbn m act a"' Ikeaatl so n 0 mad- -at ' x c vmpe dunnnsum �n c/o sae knaq mentodb Imm gIm o-al(s xa) Intnlsµeaal ax lspsaRl M'I, as) ei Rna nl tia(k an o 0 malman a"anami- no, nmea a. erg rvemen aalipnnl a aeamen az lspean[1 one a. maa nmlaRSmelYsx.1 .oass nml[/o San, aril D "nW,mnarennadsnaa paeee Yea am m lspea-di mr,x (1, xlm en1)�a alien il(,-nm .Rlaammw,m 11 .s�n.R°mmmla, 12 a. n ism a,'.am n n Wisps adl a,,,an, a:lYs nssl al ad al 11 de do an an le 7 20 cam Nm..�aaR,NB m Win) on ro uoKm m,Hro.>sgBa, yuD:eH Prang Sn n D D n B DOD Da DDR DOD .. AM) TOTAL IMPERVIOUS COVER TREATED).[) D.d AREACHECK: OR. TOMNINNAGICIDEURFARCATRICATED(aell DER AREACHECK: OR. TOTAL RUNOFF REDUCTION IN DA A IN) I . TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN DA.AOlw) OlT TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PMRNES IN D.A. A Do/yr) I D. L PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. A)IB/yr) I DO] SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULA TIONS no TOTAL RU NOFF REDUCTION IN D.A. A)N) P. NITROGEN REMOVED WITACTC H RUNOFF REDUCTION PRES IN D.A. A(IL/yr) O.A SEE WATER QUAET' COMPLIANCE TAB FOR SITE GECUTA TIONS (Infosmnlion Only) I, We[ S—K, (Cnarta, Plain) )no RR) 11. FINMng Practices )no RR) Filtering Pracices )no RAI Constrvct1d WeHantl (no RR) 12 CanrtrvcleE WttlanV ino RR) TOTAL IMPERVIOUS COVER TREATED)." D.CB AREACHECK: OR. TOTAL MANAGED FIND AREA TREATED)ae) D.CO AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE)IBfyr) 1.]O TOTALPHOSPHORUSAVAILANU FOR REMOVAL IN D.A.A)ILfyr) D.1] TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REOUCTIONPRACTICESIND.A. AIIb/yr) I D.OD TOTAL PHOSPHORUS REMOVED WITH RUNOfi REOUCTIONPRACIKES IN D.A.A)I!/yr) D]O TOTAL PHOSPHORUS LOAD REDUCIIONACHIEVED N D A AIO/yr) D]O TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP MAD REDUCTIONS IN D.A. A)IB/yr) ON SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOPF REDUCTION PRACTICES IH D.A. ALIL/yr) D.A NITROGEN REMOVED WITHOUT RUXOfi REDUCTION PMETICES IH D.A. AL14/yr) D.OI iDIAL N ITROGEN REMOVED IN D.A. A)Mfyr) D.]3 n. m w.ta w(sWYmXM_xww CorPaap_AP®lati q_[¢2p16 Drainage Area B .-I.— area A lend care. lar—I ASmis 6soB5 Csoila DSoniV1..1s..dC—r.Total Total Phosphorus Available for Removal In D.A. B(lb/yr) 0.00 Poll Development Treatment Volume in D.A. B)R)D Stormwater Best Management Practices (RR = Runoff Reduction) -sele lfrom dropdown list: Runoff Managed Impervious Volumeirom Runoff Remaining Total BMP Phosphorus Phosphorus untrearee PM1ospM1nBy Remaining %aRire Retluttl0n Turf Getlh [over Credit Upstream Reduction Runoff Treatment Removal Load from PM1ozpM1Orus Removed By Pleas hotels Downstream Practice m he Gedit i%) Area (acres) Area(acres) Pnttice QPl Qtj Volume Qtj Volume Qtj Effidenry i%) Upstream Load to Pmedlce tlb) load ila) Employed 1. Vegetated Roo,f (RR) prettires Ib Practice Ih I.a. Veg tM Roof#115Pec Ml <5 0 ]. b. VegelMetl Raatp2iSpe[MSI m 0 0 0 0 p.m O.m O.m Nitrogen Removal EfOclenryi%) Nitrogen Load Untreated from Upstream Nitrogen load Practices (IbM) to Practice(IM) Nitrogen Removed By Practice (IbM) Remaining Nitrogen Land (Had) 0 om Om om 0 O.m om O.m 0 om om om om 0 ord 0.m om nm 0 om nm om 0.m IS om A. om p.m ss om 0.m om 0.m M om A. om nm m om nm om am 0 om A. om 0.m a0 om 0.m om 0.m zs om om om om zs am om am 20 am am om a.m zo ado 000 no, o.m z0 om am om 0.m zs om om om 0.m 11 om am om a.m as om nm A. 0.m m om om o.m om nmmn smcrnsiwe1sA4YSRN R�'_curEeso_spwel®I_� os2ms DkB TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHEIX: OK. Mrro"URF AREA TREATED (ac) 0.00 AREA CHECK OK. TOTAL RUNOFF REDUCTION IN D.A B (f['I 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL:: O.A B(Ib/yr) O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. B )Ib/yr) O.W TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICE IN D.A B(lb/yr) O.CO SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS 10.a.WHSwalepl (Specpill 0 0 0 0 0 20 lOb. Wet Swale p3 Spec IUU 0 0 0 0 0 anO.m O.m "..Ferri n6 Patties Al t1nee.121 Ilh Flaenng PnRice V line, 012) 0 0 0 0 0 65 n.m n.m O.m O.m 13. Wet Ponds (no RR) 13a. writ runes xt:speexla) o o (1 0 (I SO o.m 13b. WcfPand n iCenal Main) (SP consi B o p B p as B.00 o.m B.m On 13<. wx Poneaz (spe, ales) B a a o a Ts B.m a.m o.m B.m 13J. Wet PanE N2tli,eaA..in) n,cc Off If 0 0 0 0 65 O.On Om O.m Om 14. Manufactured Treatment Devices (no 14 a. laanulacturM ReaMent LYriec NytlrMynae'r RR) 0 0 0 0 (1 20 O.m O.m O.m O.m ]. Infiltration AR) I. Worded Gained.. Pond (RR) 9. Sheetflow to Nlter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. B (fty� NITROGEN REMOVED WITH RUNOFF REDUCTION PRAMCES IN O.A. B(lb/,) O.OU SEE WATER QUALITY COMPLIANCE TAB FOR SITE INUCULATIONS(1njormation Only) 10. Wet Swale (Coastal Plain) (no RR) 11. Filtering PreCkcs(no RR) 12. Cons[rutted Wa land (no RR) 13. Wet Ponds (no RR) 30. Manufactured BMP (no RR) sol'etahAWRRN RAR_cmFem spwel®I_� oUmsDAR TOTAL IMPERVIOUS COVER TREATED (ac) O.OB AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED Jac) 0.00 AREACHEC OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE(Ib/yr) 1.30 TOTAL PHOSPHORUS AVAIIABLE FOR REMOVAL IN O.A. B ,Ib/yF) O.W TOTAL PHOSPHORUS REMOVED WFNNIUT RUNOFF REDUCTION PRACTICES IN DA. B(IIb/yT� O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. B �Ib/yt� DOD TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED INO.Ab/yF) D.CO TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN DA.B(Ib/yT) D.W SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCUTA TIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. R :Ib/yt� O.CO NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA. a alb/yt� DoU TOTAL NITROGEN REMOVED IN MA. B(Ib/yT) U.CO Drainage Area C Daainaae <aea GLane finer 1-1 A.Hk ..ii, C.ila Dl IlaV1..Ik..dC—r.Total m w.ta R9,B Vi n Ranea �_RP®omo w eVo a DAC Total Phosphorus Available for Removal in O.A. C(lb/yr) O.OD Poet Development TreatmentA Qt Volume In D.C 'i 0 Stormwater Best Management Practices (RR = Runoff Reduction) -selettfrom dropdovan list: Runoff Managed Impervious VUpstre Runoff Remaining Tota1BMP PM1ommou,s Phmpnmua Untrearee Remaining %aRire Reduction Turf rretlh Cover Creelt in Upstream Reduction ftunoH Treatment Removal Load from PM1ozphorus RemoV dBy Removed By Phosphorus Downstream Prattlrembe Uedit Gedh i%) I%) Area (acres) Area (acres) practice (R') )R') Volume )ft') Volume tft'i EPodenry i%) Upstream Load to pnttke (lb) mad ilb) Employed 1. Vegetated Ravi RR) Prattitts Ib Prattice Ib la. VegtatM Roof#115Pec M1 <S 0 ]. b. VegelMetl Raatp2iSpe[MSI m 0 D 0 D D.m O.m O.m Nitrogen Removal EfOdenry (%) Nitrogen Load Untreated from Upstream Nitrogen mad P.W. ilbsi to Pm.ke(IM) Nitrogen Removed By PraPtire (lbs) Remaining Nitrogen Load ilbsi 0 Om Om Om D O.m lint O.m 0 0m 0m om 0m 0 0m 0.m 0m Bm 0 0m 0m 0m 0.m ss 0m 0m 0m a.m ss 0m 0.m 0m 0.m M 0m Bm 0m Bm an 0m Bm 0m am 0 0m Bm 003 0.m a0 0m 0.m 0m 0.m zs 0m 0m 0m 0m zs am om am zD am am 0m a.m zD aDD o00 lint D.m zD 0m am 0m 0.m zs 0m 0m 0m 0.m 11 om am lint a.m as 0m Bm and 0.m m om 0m om 0m nmmn sore.'. wu1s1a4wARNR�'_cunea�o_sP-wdw, ✓i_pMms DAG TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTALMANAGFD TURF AREA TRFATED(a) 0M AREA CHEC :OK. TOTAL RUNOFF REDUCTION IN D.A. C(R') 0 TO TAI PHOSPHORUS AVA. IABLE 10RREMOVA1:N DA C)Ib/yr) O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACNCES IN DA.CQb/yF) O.W TOTAL PHOSPHORUS REMAINING AFTERAPPLYING RUNOFF REDUCTION PRACTICES IN DA. C(Ib/yr) O.CO SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS 10. Wet Swale I no RR) IOa.WHSwdr M1(5pe....1 . 0 0 0 0 20 mn swa',sdcc2lSpeep111 0 11A.linenng Practice al D11.12) o a o 0 o IIb. F l nenng Practire 92 c ow M12) 0 . 13. Wet Ponds (no RR) 13.a.WH Pontl p]ISpe[kIK1 0 a 0 . 0 St O.U] Ant nw raw 13b. WitPmtl 111Coastal Main)(Specind) 0 0 0 0 0 <5 O.W OO] 0.W O.O] 13.c Wet PoM p2Dpectll0) 0 0 0 0 0 ]S Ann At ILW ADD 13tl. Wet Pond p2 D so Gl%ain) DS 110) 0 0 0 0 0 65 OW o.W OW O.W 14. Manufactured Treatment Devices (no 14.. Manutarmrsi Iron ent Device Hymnawaanm RR) o o . o o ro ono o.00 a.00 o.m ]. Infiltration (RR) R. 4lended Deduction Pond (RR) 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN DA C (R) 0 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA C (lb/yr) I LOU SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale (Coastal Plain) (no RR) 11. Filtering PraeOces(no RR) II. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 30. Manufactured BMP (no RR) so FetahAWRRN RAG_cmFem spwel®I_� oUmsDAG TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OR. TOTAL MANAGED TURF AREA TREATED Lac) O.OU AREACHEC OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SIDE (Ib/yr) 1.10 TOTALPHOSPHORUS AVAILABLE FOR REMOVAL IN D.A.CIIb/yl� O.W TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA. C Bb/yrI O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PMCTICESIN OA. C �Ib/yt) 0.DO TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.AC�Ib/,T� O.W TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN DA. C (lb/yr) O.W SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCUTA TIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN O.A. C �Ib/yF) O.CO IOGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN OA. C Bb/y.I O.W TOTAL NITROGEN REMOVED IN DA CIIb/yF) O.00 Drainage Area D Drainage Grua. land cam, larr-I ASmis 6so05 csolls DSollsO..k..dC—r.Managedl, leoes) Total ran X9 (BpeFNmN ReDai CorPagp_eP�1ati w [62p16 DAD Total Phosphorus Available for Removal In DA D(lb/yr) 0.00 Postievelopmem n[VOIume TrearmeIn O.A.OQt'i 0 Stormwater Best Management Practices (RR = Runoff Reduction) -seleafrom dropdogan Ilan: Runoff Managed Impervious Vomit.from Remaining g Tota1BMP Phosphor us Phmphmnu Untreated Pdmon,asphdrus Remaining %aRire Turf Getlh Area(Ercdh Upstream doodoemo Reducnian ftunoH Treatment Removal Load from PM1ozpbarus Removed By PWad(1b) Downstream Prattlrembe CreditRedultion %) Credit i%) Area (acres) Area (acres) practice (R') )R') Volume )ft') Volume tft'i EPodenry (%)) Upstream Loadm pnttke (lb) mad ilb) Employed 1. Vegetated Romf RR) Prattices Ib Prattice Ib Is, VegeUtrd Roof#115Prt Mi <5 0 1.b.VegetMed Raal.2JSII.) m 0 0I 0 Nitrogen Removal EfOdenry i%) NBmgen Load Umreated from Upstream Nitrogen mad Practices ilbsi so Prattke Qbs) Nitrogen Removed By Prelate (lba) Remaining Nitrogen Load ilbsi 0 om Om om 0 O.m om O.m 0 om om om om 0 and 0.m om D. 0 om om om 0.m IS om om om D. ss om 0.m om 0.m M om nm om nm m om D. om am 0 om It. om 0.m a0 om 0.m om 0.m zs om om om om zs am om am 20 am am om a.m 20 ado ow om 0.m 20 om "D 0m 0.m zs om om om 0.m 11 om am on. a.m as om D. m om om om om nmmn sore to wu1s1a4b'sRN Raaa_cmFeso_sp clods, Pcdr. DAD TOTAL IMPERVIOUS COVER TREATED (au) D.00 AREA CHECK: OK. TOTAL MANAGED TURFARFA TREATED (ae) O.DO AREA CHEIX: OK. TOTAL RUNOFF REDUCTION IN D.A D )ftt) 0 TOTALPHOSPHORUSAVAILABLEFORREMOVALIND.A.0)Ib/yr) O.W TOTALPHOSPHORUS REMOVEDWITH RUNOFF REDUCTION PRACTICES IN OA D(Ib/yr) O.W TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN DA. D(lb/,) O.CO SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS IOa.WHSwale M115pe....I 0 0 0 0 0 mD w,,,sdcc2lSPeep111 11A.Finenng P.li[e of Duee.12) o a o 0 o fA a.A, IIb. F l nenng PrzRioe 92 SPee M12) 0 0 0 0 0 65 OAn O.A, OW O.A, 13. Wet Ponds (no RA) 13.a.Wel Pond KllS,e Mla) 0 0 n 0 0 50 O.U] Ann Dw Ow 13b. WctPmtl NllCaDoalMain) )SPea F10) 0 0 0 0 0 <5 0.At OO] 0.W O.A, 13.c Wet PoMp2)SPeetl10) 0 0 0 0 0 75 Ann An ILW ADD 13E. Wtt Pond N2 D rastal Main) DS 110) 0 0 0 0 0 65 O.A, o.W O.At O.A, 14. Manufactured Treatment Devices (no 14.. ManulaRurM TreaMent Oevi— Hydrmwan,m MR) o o a o n zo DA, B.BB a.BB B.m ]. Infiltration IRK) S. Worded Deduction Pond (RR) 9. Sheetflow to Nlter/Open Same (RR) TOTAL RUNOFF REDUCTION IN O.A. D IN') 0 NITROGEN REMOVED WITH RUNOFFREOUCTIONPRARICESINDA.O(lb/yr) D.DO SEE WATER CILMU YCOMPLIANCE TAB FORSITECALCULATIONS(Information Only) 10. Wet Swale (Coastal Plain) (no RR) 11. Filtering PratUces(no RR) U. Constructed Wetland (no RR) 13. Wet Ponds (no FR) 30. Manufactured BMP (no RR) so FetOhAWRRN_R�_cmFem spwn®I_✓i_DUms DAD TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED Jac) O.OU AREA CHEC OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SIDE(Ib/yr) 1.10 TOTALPHOSPHORUS AVAILABLE FOR REMOVAL IN D.A.O �Ib/yt� co TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUMON PRACTICES IN D.A DBb/yr) O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCFION PRACTICES IN DA. D Bb/y.I O.W TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN DA.O �Ib/yF� O.W TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN DA.D(lb/yr) O.W SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICESIN O.A. DBb/yr) O.CO NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACFICFS IN O.A.DBb/yr) O.W TOTAL NITROGEN REMOVED IN DA.0 (Ib/yF) 0.00 19N3i 1¢91 Mt Drainage Area E 11-1 en area A land finer [soar[ A.Hk ..fl, csolla Il sopsVI..lk..dC—r.Total m w.ta w(sW4vnxM_xww CorPaap_AP�Itl_w [¢2p16 DAE Total Phosphorus Available for Removal in B.A. E (lb/yr) Po.00 st Development Treatmm Volume to Voluin D.A.BA E(t'i B Stormwater Best Management Practices (RR = Runoff Reduction) -selettfrom dropdown list: Runoff Managed impervious VUpstre Runoe Remaining Tuaa1BMP Pgarearrus Phosphorus Untreamd Remaining %aRire 0n Turf Getlh Area(Ercdlt An Upstream Reduction ftunoH Treatment Removal Load from PM1ozphOrus Removed By RemovedaephoBy PWad(l Bownstream Prattlrembe Credit Credit i%) Area (acres) Area (acres) practice (R') )R') Volume )ft') Volume tft'i EPodenry i%) Upstream Load to prettke (lb) mad (lb) ) Employed 1. Vegetated Rac,f (RR) Prattices Ib Practice Ib la. VegtatM Roof#[(Spec M) 0 ]. b. VegelMetl Raatp2(Spe[MSI Bem 0 0 0 0 p.m O.m O.m Nitrogen Removal EfOclenry (%) Nitrogen Load Umreated from Upstream Nitrogen mad Practices iibsi to Practice(Ibs) Nitrogen Removed By PraeNre(lo) Remaining Nitrogen Lead ilbsi 0 om Om om 0 O.m om O.m 0 om om om om 0 and 0.m om nm 0 om Bm om 0.m 11 om om om d.m ss om 0.m om 0.m ad om A. om nm on om nm om am 0 om Bm om 0.m a0 om 0.m om 0.m zs om om om om zs am om am 20 am am om a.m 20 a.a0 ow om 0.m z0 om am 0m 0.m zs om om om 0.m 11 om am om a.m as om nm And 0.m m om om om om nmmn sore'..welyw4wARN R¢aa cuneao_s,wn®I_✓i_PMms TOTAL IMPERVIOUS COVER TREATED )ac) 0.00 AREA CHECK: OR. TOTAL MANAGED TURFARFA TREATED )ac) 0.00 AREA CHEIX: OR. TOTAL RUNOFF REDUCTION IN O.A. E(Na) 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL:: D.A E)Ib/yr) O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. E O.W TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A E(Ib/yr) O.CO SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS 10. Wet Swale I no RR) IOa.WHSwdr.,(sPe.... I . . 0 0 0 IO b.WnSwale p3 Spe[p111 0 . 0 0 0 b O.O] OU] ]].a.F'Medng P.1ire of lS11.12) . o 0 0 o fA a.An IIb. F l nenng PrzRire 92 c,sw M11) 0 . 0 0 0 E, OD] O.An OW O.An 13. Wet Ponds (no RR) 13.a.WH Pantl p]l5pe[k1al 0 a 0 0 0 50 O.U] Arn n0c, raw 13b. WttPand pllCoastal Main) Gpcc N1,d 0 0 0 0 0 IS 0.An OAn 0.W An 13.c Ysttsora lSPeetl101 0 0 0 0 0 ]S Ann All ILW Ann 13tl. WttPand XrHsastal Main)(Sptta10) 0 0 0 0 0 6S OW o.W 0.At 0.At 14. Manufactured Treatment Devices (no 14.. ManutarturM Iron ent Lee- Hrmaawaanm RR) o o . o R ro ,Ao R.W a.W R.W ]. Infiltration (RR) R. Worded Detention Pond )RR) 9. Sheetflow to HIter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A E III) D NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. E)Ib/yr) D.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS fI formation Only) 10. Wet Swale (Coastal Plain) (no RR) 11. Filtering PraNces(no RR) II. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 30. Manufactured BMP (no RR) sol'et0 welyw4L'sRN RHM curEem spwel®I_✓i_oUms TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED Jac) O.OU AREA CHEC OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE(Ib/yr) 1.10 TOTAL PHOSPHORUS AVAIIABLE FOR REMOVAL IN O.A. E 1Ib/YTS O.W TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA. EBb/yr) O.W TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN DA. E �Ib/yt) DOD TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN O.A.E�Ib/yF� O.CO TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN DA. E(Ib/yr) O.W SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCUTA TIONS VOFF REDUCTION PRACTICES IN DA. E pl Zy O.CO VOFF REDUCTION PRACTICES IN DA. E Bb/y.I O.W TOTAL NITROGEN REMOVED IN D.A.E(Ib/yF) O.00 Site Results (Water quality Compliance) area aeaw urpxn s.e¢I�Ia. rtalx WIas Holy sR. rr.aam.Mwu.nam� .m R-W easuttbn vulune as rP By Dreasp Nea m nam ioW ftaSpRoru[ 2 as e a�al�Nnl- ioW Ni4oRen lForlMormaabn Puryanl I oamap Area curve xumbea and NunoHDeolne I I I Virginia Runoff Reduction Method Worioneet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Draft Stds & Specs Site Summary Total Rainfall (in): 43 Total Disturbed Acreage: 2.02 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) Asoils BSoils CSoils DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.59 0.59 29 Managed Turf (acres) 0.00 0.00 0.00 0.86 0.86 43 Impervious Cover (acres) 1 0.00 0.00 1 0.00 0.57 0.57 28 2.02 100 Post-ReDevelopment Land Cover (acres) Asoils BSoils CSoils DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 1 0.00 1 0.00 0.00 1.08 1.08 53 Impervious Cover (acres) 1 0,00 0.00 0.00 0.94 0.94 47 2.02 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post Pos<- Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment Nlm ervious &ew p ) (New Impervious) Site Rv 0.58 0.49 0.95 0.47 Treatment Volume(its)4,222 2,946 1,276 2,786 TP Load (lb/yr) 2.65 1.85 0.80 1.75 Total TP Load Reduction Required (lb/yr) 1.10 0.45 0.65 Final Post -Development load (Port-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load Ilb/yr) 18.98 12.82 Pre- ReDevelopment Final Post -Development Post-ReDevelopment TP TPLoadpeyr) TP Load per acre Load per acre (Ib/acre/yr) (lb/acre/yr) Ib acre 1.06 1.31 1.12 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Site Compliance Summary Maximum% Reduction Required Below 20% Pre ReDevelopment Load Total Runoff Volume Reduction (Its) 124 Summary Print Virginia Runoff Reduction Method Worio heel Total TP Load Reduction Achieved (lb/vr11 0.10 I Total TN Load Reduction Achieved (lb/vr)l 0.73 1 Remaining Post Development TP Load I 2.55 Remaining TP Load Reduction (lb/yr)I 1.00 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Drainage Area Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acres) 0.00 0.00 0.00 0.00 0.00 0.00 I mpervious Cover (acres) 0.08 0.00 0.00 0.00 0.00 0.08 Total Area (acres) 0.08 0.00 0.00 0.00 0.00 0.08 Drainage Area Compliance Summary D.A. A DA. B D.A. C DA. D D.A. E Total TP Load Reduced (lb/vri 1 0.10 0.00 1 0.00 1 0.00 0.00 0.10 TN Load Reduced (lb/yr) 1 0.73 0.00 1 0.00 1 0.00 0.00 0.73 Drainage Area A Summary Land Cover Summary A Soils BSoils CSoils DSoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.08 0.08 1 100 0.08 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I s Volume (it) Upstream to Practice (lbs) (Removed (Ib/yr) to be Employed acres Area acres Practices Ibz Total Impervious Cover Treated(acres) 0.08 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. b/ r 0.10 Total TN Load Reduction Achieved in D.A. 0.73 b/ r Summary Print Virginia Runoff Reduction Method Worioneet Drainage Area B Summary Land Cover Summary A Soils BSoils CSoils DSoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downrtream Treatment Practice Credit Area Cover Credit I s Volume (it) Upstream to Practice (Ibs) (lb/yr) (lb/yr) to be Employed acres Area acres practices (Ibs Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Drainage Area C Summary Land Cover Summary A Soils BSoils CSoils DSoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downrtream Treatment Practice Credit Area Cover Credit I Volume (it') Upstream to Practice (Ibs) (Removed (lb/yr) to be Employed acres Area acres Practices Ibs Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Drainage Area D Summary Land Cover Summary Summary Print Virginia Runoff Reduction Method Worio heel A Soils BSoils Csoils DSoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I s Upstream Volume (k) to Practice (Ibs) (Ib/yr) (Ib/yr) to be Employed acres Area acres practices Ihs Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. h/ r 0.00 Total TN Load Reduction Achieved in D.A. h/ r 0.00 Drainage Area E Summary Land Cover Summary A Soils BSoils Csoils Dsoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious TP Load from BMP Treatment TP Load TPRemoved TP Remaining Downstreamam Treatment Practice CreditUntreated Cover Credit I Upstream Volume (it') ( to Practice (Ibs) (16/yr) (Ih/yr) to be Employed ts) acres Area acres practices Ibs Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. h/ r 0.00 Total TN Load Reduction Achieved in D.A. Ih/ r 0.00 Runoff Volume and CN Calculations 1-yearrtorm 1 2-yearstorm 1 10-yearst22 Target Rainfall Event (in) 2.92 3.54 S_3S Drainage Areas I RV&CN I Drainage Area I Drainage Area 1 Drainage Are.c I Drainage Area I Drainage Area Summary Print Virginia Runoff Redurbon Method Worksheet CN 98 0 0 0 0 RR 111) 124 0 0 0 0 1-year return period RV wa RR jwz-ini 2.69 0.00 0.00 0.00 0.00 RV w Re jws-in) 2.26 0.00 0.00 0.00 0.00 M adjusted 94 0 0 0 0 2-year return period RV wa RR)wzin) 3.31 0.00 0.00 0.00 0.00 RV w RR (ws-in) 2.88 0.00 0.00 0.00 0.00 CN adjusted 94 0 0 0 0 30-year return period RV was RR(ws-in) 5.11 0.00 0.00 0.00 0.00 RV w RR 1-s n) 4.69 0.00 0.00 0.00 0.00 CN adjusetl 94 0 0 0 0 Summary Print 20.09.10 Kesvnck_Hall (Spa)-VRRM_ReDev_Compliance _Spreadsheet_v3_D52016 Ve ndon IS -June 2014 -2011 BMP Stds & Since 1 Fixed summary sheet - totals/percentage column fixed 2 Corrected nitrogen efficiency percentages 3 Connected the Rv value in column J for managed turf 4 Checked and revised runoff reduction credit values assigned Version 3.0 - 2011 and drag 2013 BMP Stds & Specs General 1 Addetl error Marks and user prompts to Site tab, DA tabs, and Runoff Volume and CN tab for data Input errors. 2 Various format changes thoughout the spreadsheet. 3 Combined 2011 and 2013 BMP spreadsheets Into one spreadsheet with a user selection option included in Site tab. 4 User input cell color changed from cyan blue to green; calculation cells changed from mid -grey to light grey; and added final result cell in indigo. See tab 5 Locked annual minfall of 43 inches for use throughout Virginia since regulatory site based TP load limit is based on this value. 6 Corrected error in formula for total frustums bad reduction requirement. Previous formula was inconsistent with 9VAC25-e7663 A.2 and under certain circumstances provided erroneous TP load reduction requirement for development on prior developed lands. T Added button and shorted (CW+Sli fl+R) to clear user inputs from all worksheets. 8 Added shortcut (CM+Shill+D) to door land cover data from Site tab. 9 Added TP Baseline Load for adjusted pre-redevelopemed portion (cell C58). 10 Added note (triggered to appear when applicable) below "Land Cover Summary for RecievelopmenF-indicating that reduction below baseline TP load (<041 In/acre) not required as per 9VAC25E1063. 11 Ardent error messages when data input areas incomplete or not entered correctly. 12 Counfillenal formatting (Summary sections grayed out) omen input information incomplete or incorrect. 13 Added Pre -redevelopment and Post -development load In Ibscurelyr (row 57) for additional comparison purposes 14 Corrected error in excel formula for navy impervious cover Rv. 15 Corrected errors in excel formula for total site area and RVs in redevelopment portion: error appeared when sell types change between pre -redevelopment and postdevelopment with no net increases in impervious increase. 16 Added section for Final Post -Development to Land Cover Summaries to show combination of redevelopment portion and navy net impervious cover potion. 1] Added inkon itional notion in blue (columns B to F. roars 12-14) and inpWerror am guide (columns H to K, rows 12-14) to indicate M users upfront en new neom t impervious cover is being triggered, en 10 or 20% suburban uans are being utilized, am Men data entry is completed correctly. 18 Added data entry instruction when user inputs blank (row 8). 19 Added option for linear development projects (row 6, and cells 084G64) DA tabs 20 Added WDs: Hydrodynam c, Filtering, Generic. 21 Added Total BMP Treatment Volume (r" column. 22 Rearranged previous Turf add Impervious input roars to adjacent cells In same row so each practice now located on 1 row only. 23 Consolidated BMP Practice heading and added (RR or no RR label) to each preetice to Identify, those with and without Runoff Reduction. 24 Added "Total Phosphorus Available for Removal in D.A- _ (Ins)". 25 Added button to dear BMP credit areas entered for each pri 26 Added user prompts to assist with user -input Rainwater Harvesting runoff reduction credit, and MTDs. 27 Renamed Credo ant Phosphorus/throgen Efirency column headers to Runoff Removal Credit and Phosphow"Itogen Removal Efficiency for parity. 28 Removed "RR" from Column headings entering to runeff volume and TP lead from upstream practices (which may be RR or nori practices). 29 Renarreci "10. Wet Swale (Coastal Plain)" to "10, Wet Swale" in BMP heading in order to Improve clarity. The practice is well sugar for but net limited M Me Coastal Plain. 30 Renamed 14, Manufactured BMPs" section heading to "14. Manufactured Treatment Device 'a for consistency win Virginia BMP Clearinghouse. 31 Added "Mtcro-Bioretention #1"and "Micro-Bioretenfion #2" to Bleretenfion headings (6.a and 6.b on tab, respectively) from Spec 9. 32 Replaced zero values from all data entry cells with blank cells, blocked out calculation and data entry cells where input or calculations are not applicable. Water Quafiry, Comphi n e, tab 33 Optimized and reorganized for improved tnfommtion output. 34 Added "Runoff Reduction Volume and TP By Drainage Ami 35 Added section for linear development projects (rows 21-26) Runoff Volume add CN tab 36 Reorgantzeci and renamed Channel and Flood Protection tab to Runoff Volume and CN to more accurately re0ect information provided. 37 Added user notes regarding limitations of Runoff Volume and CN tab for water rummy calculations. 38 Renamed CN„y fe to CNimaxl for the Cuts based on soils and land cover types for each drainage area Supposai b 39 Added Tint Preview" button. 40 Fixed runtime error in Summary tab update mane. 41 Added "BMP Treatment Volume", "TP Load from Upstream practice", TP Removed" ani remaining" columns to Summary tab. 42 Optimized macro efficency and eliminated screen updatingMashing during macros. 43 Corrected Summary tab macro -Turf missing routine missing "o 00 Ancient additional pro antl post site data onto Summary tab. 45 Added Error Summary Table to Summary tab (appears only donors on Site tab or Drainage Area one are present) 46 Expanded and Improved Runoff Coefficient and CN calculation section. 47 Ardent summary information for linear projects, only populates if applceble. 4S 13L Pre Area 1-1 (Offsite) Areas Combined (1-1 + 1-2) 12S Pre Area 1-2 (Onsite) Subcat Reach Ofl Link Routing Diagram for Keswick Hall_ Spa_ Analysis Points 1 (PRE)_VE 2020-08-2 Prepared by Timmons Group, Printed 10/19/2020 HydroCAD®10.00-20 sin 08663 0 2017 HydroCAD Software Solutions LLC Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-20 Prepared by Timmons Group Printed 10/19/2020 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 1.150 80 >75% Grass cover, Good, HSG D (4S, 12S) 1.010 98 Paved parking, HSG D (4S, 12S) 0.610 77 Woods, Good, HSG D (4S, 12S) 2.770 86 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-20 Prepared by Timmons Group Printed 10/19/2020 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 2.770 HSG D 4S, 12S 0.000 Other 2.770 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-20 Prepared by Timmons Group Printed 10/19/2020 Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover 0.000 0.000 0.000 1.150 0.000 1.150 >75% Grass cover, Good 0.000 0.000 0.000 1.010 0.000 1.010 Paved parking 0.000 0.000 0.000 0.610 0.000 0.610 Woods, Good 0.000 0.000 0.000 2.770 0.000 2.770 TOTAL AREA Subcatchment Numbers 4S, 12S 4S, 12S 4S, 12S Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 5 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment4S: Pre Area 1-1 (Offsite) Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>1.45" Tc=7.0 min CN=84 Runoff=1.84 cfs 0.091 of Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 42.57% Impervious Runoff Depth>1.67" Tc=7.0 min CN=87 Runoff=5.65 cfs 0.281 of Link 13L: Areas Combined (1-1 + 1-2) Inflow=7.49 cfs 0.371 of Primary=7.49 cfs 0.371 of Total Runoff Area = 2.770 ac Runoff Volume = 0.371 of Average Runoff Depth = 1.61" 63.54% Pervious = 1.760 ac 36.46% Impervious = 1.010 ac Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 1.84 cfs @ 11.99 hrs, Volume= 0.091 af, Depth> 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.92" Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 4S: Pre Area 1-1 (Offsite) Hydrograph 2 1.84 cfs Type II 24-hr 1-YR Rainfall=2.92'r Runoff'Area=0.750 ac Runoff Volume=0.091 of Runoff Depth>1.45" Tc=7.0 min CN=84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 5.65 cfs @ 11.98 hrs, Volume= 0.281 af, Depth> 1.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=2.92" Area (ac) CN Description 0.860 98 Paved parking, HSG D 0.570 80 >75% Grass cover, Good, HSG D 0.590 77 Woods, Good, HSG D 2.020 87 Weighted Average 1.160 57.43% Pervious Area 0.860 42.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 12S: Pre Area 1-2 (Onsite) Hydrograph 6 5.65 cfs Type II 24-hr 5 1-YR Rainfall=2.92" Runoff'Area=2.020 ac 4 Runoff Volume=0.281 of Runoff Depth>1.67" 3 Tc=7.0 min CN=87 2 --- - - - - -- 9- 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.770 ac, 36.46% Impervious, Inflow Depth > 1.61" for 1-YR event Inflow = 7.49 cfs @ 11.98 hrs, Volume= 0.371 of Primary = 7.49 cfs @ 11.98 hrs, Volume= 0.371 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 13L: Areas Combined (1-1 + 1-2) a 7.49 __i__y__r__"__1__"__�__"__ I I I I I I I I I I 7 I I L _J__1__L__I__J__1__L__L _J_ I I I I I I I I I I I I I I I I I I I I 6 -1 -T I I I I I I I I I I 5 M J1LIJ1__L__I__J_ YV"• I I I I I I I I I I O 4 -T -r -I -1 -T -I 3 I I I I I I I I I I I I I I I I I I I I 2_. I I I I I I I I I ---------------------------- ____ ■Infl aW ■ Prima I I I I I I I I I I ry ;fs _���wl�►i�??:I��{�"Ian-- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -I -1 -T -r -I -1 -T -r I I I I I I I I I I I I I I I I I I I I I 1__L__IJ1L__I__J__1__ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I T-1 -T -� -I -1 -T I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 1 I I 1 1 I I 1 1 I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 9 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment4S: Pre Area 1-1 (Offsite) Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>1.97' Tc=7.0 min CN=84 Runoff=2.48 cfs 0.123 of Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 42.57% Impervious Runoff Depth>2.22" Tc=7.0 min CN=87 Runoff=7.43 cfs 0.373 of Link 13L: Areas Combined (1-1 + 1-2) Inflow=9.91 cfs 0.496 of Primary=9.91 cfs 0.496 of Total Runoff Area = 2.770 ac Runoff Volume = 0.496 of Average Runoff Depth = 2.15" 63.54% Pervious = 1.760 ac 36.46% Impervious = 1.010 ac Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 2.48 cfs @ 11.98 hrs, Volume= 0.123 af, Depth> 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 4S: Pre Area 1-1 (Offsite) Hydrograph 2.48 cfs Type II 24-hr 2-YR Rainfall=3.54" 2 Runoff'Area=0.750 ac Runoff Volume=0.123 of Runoff Depth>1.97" Tc=7.0 min CN=84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 7.43 cfs @ 11.98 hrs, Volume= 0.373 af, Depth> 2.22" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 0.860 98 Paved parking, HSG D 0.570 80 >75% Grass cover, Good, HSG D 0.590 77 Woods, Good, HSG D 2.020 87 Weighted Average 1.160 57.43% Pervious Area 0.860 42.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 12S: Pre Area 1-2 (Onsite) Hydrograph a LLO 5 7.43 cfs III Type II 24'. -h- r 7 2-YR Rainfall=3.54" 6 Runoff'Area=2.020 ac Runoff Volume=0.373 of Runoff Depth>2.22" 4 Tc=7.0 min CN=873 2 I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-08-Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.770 ac, 36.46% Impervious, Inflow Depth > 2.15" for 2-YR event Inflow = 9.91 cfs @ 11.98 hrs, Volume= 0.496 of Primary = 9.91 cfs @ 11.98 hrs, Volume= 0.496 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 13L: Areas Combined (1-1 + 1-2) ■ InflInflow ow Area-=2.770 ac- ■ Primary I i it I I i I I I j I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I L__I__J__1__L_ I__J__1__L__L_ I I I I I I I I I I I I I I I I I I I I ___ ---- _______---- ______________ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-09-ype 1124-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 13 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment4S: Pre Area 1-1 (Offsite) Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>3.59" Tc=7.0 min CN=84 Runoff=4.42 cfs 0.224 of Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 42.57% Impervious Runoff Depth>3.89" Tc=7.0 min CN=87 Runoff=12.67 cfs 0.655 of Link 13L: Areas Combined (1-1 + 1-2) Inflow=17.09 cfs 0.880 of Primary=17.09 cfs 0.880 of Total Runoff Area = 2.770 ac Runoff Volume = 0.880 of Average Runoff Depth = 3.81" 63.54% Pervious = 1.760 ac 36.46% Impervious = 1.010 ac Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-09-ype 1124-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 4.42 cfs @ 11.98 hrs, Volume= 0.224 af, Depth> 3.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.35" Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 4S: Pre Area 1-1 (Offsite) Hydrograph 4.42 cfs Type II 24-hr 4 10-YR Rainfall=5.35" Runoff'Area=0.750 ac 3- Runoff Volume=0.224 of I Runoff Depth>3.59" Tc=7.0 min 2 CNy84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-09-ype 1124-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 12.67 cfs @ 11.98 hrs, Volume= 0.655 af, Depth> 3.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.35" Area (ac) CN Description 0.860 98 Paved parking, HSG D 0.570 80 >75% Grass cover, Good, HSG D 0.590 77 Woods, Good, HSG D 2.020 87 Weighted Average 1.160 57.43% Pervious Area 0.860 42.57% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, 10 0 LL Subcatchment 12S: Pre Area 1-2 (Onsite) Hydrograph I I I I I I I I I I I I __+- --- 12.1 I I I I 1 1 1 I I I I l I l i I I I I I I I I I 1 1 1 1 1 1 I I I I 111_I.1__I_ I I I 1 1 1 1 1 1 I I I I 1 1 1 1 1 1 1 1 1 1 1 1 I I I I I I 1 1 1 1 I I I I 1 1 1 1 1 1 ---------------------------- I I I I I I I I I I I I I I I I 1 I I I I I I I I 1 I I I I I I I 1 I I I I I I I I I 1 I I I I I I I 1 I I I I I I I 1 I I I I I I I 1 I I I I I I I I I + I I � '' ❑ Runoff Type 11 24-hr 10-YR Rainfall=5.35" Runoff Area=2.020 ac RunoffVolume=0.655 of --Runoff Deptiv>189 l - Tc=7.0 min I I I QN= 87 I I I I I I I I I I I I I I I I I I I I I I_ __I _ _ ___ - I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (PRE)YE 2020-09-ype 1124-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 U-A—OAM( An nn on aI- n0nn4 (, On17 n--- nC Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.770 ac, 36.46% Impervious, Inflow Depth > 3.81" for 10-YR event Inflow = 17.09 cfs @ 11.98 hrs, Volume= 0.880 of Primary = 17.09 cfs @ 11.98 hrs, Volume= 0.880 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 13L: Areas Combined (1-1 + 1-2) Hydrograph 19 I I I I I l l l l 17 16 14 .' --I--�--r--r I I -r--r--r--r 13 12 11 ,' _ J_ v 10 I I I LL a J__1__ L__I__J__J__ L__I__J_ 7 J__1__L__I__J__1__L__I__J_ 6 J__1__ L__I__J__1__L__I__J_ 5 I I I I I I I I I I 4 i i 3 - '... FE Inflow ❑ Primary ' Inflow Area=2.77o ac I I --r--I--r--r--r--I--r--r--r--I-- --I_ ___I__r__r__r__I__ I I I I I I I I I __I___I__J__1__L_J__J__L__L__L_J__ I I I I I I I I I I I _._L__I__J__1__L_J__J__1__L__L_J__ 1 I I L_J__J__1__L__L_J__ 1 1 I LJ__1__L__L_J__ 1 J__1__L__I__J__1__L__L__I__ I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Post Area 1-3 (Offsite, detained) 19P 17S 2S \p 18L ' ��` Area 1-5 (Onsite, SWM 3 Undetained) Post Area 1-4 (Onsite, Detained) Areas Combined Subcat Reach Aon Link Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09-10 Prepared by Timmons Group Printed 10/19/2020 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 1.420 80 >75% Grass cover, Good, HSG D (1S, 17S) 1.330 98 Paved parking, HSG D (1S, 2S, 17S) 0.020 77 Woods, Good, HSG D (1S) 2.770 89 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09-10 Prepared by Timmons Group Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 2.770 HSG D 0.000 Other 2.770 1S, 2S, 17S YA11CA WIN=El Printed 10/19/2020 Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09-10 Prepared by Timmons Group HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Printed 10/19/2020 Page 4 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.000 0.000 1.420 0.000 1.420 >75% Grass cover, Good 1S, 17S 0.000 0.000 0.000 1.330 0.000 1.330 Paved parking 1S, 2S, 17S 0.000 0.000 0.000 0.020 0.000 0.020 Woods, Good 1S 0.000 0.000 0.000 2.770 0.000 2.770 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09-10 Prepared by Timmons Group Printed 10/19/2020 Pipe Listing (all nodes) Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Inside -Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 19P 422.00 420.00 50.0 0.0400 0.013 18.0 0.0 0.0 Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: Post Area 1-3 (Offsite, Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>1.45" Tc=7.0 min CN=84 Runoff=1.84 cfs 0.091 of Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=0.910 ac 100.00% Impervious Runoff Depth>2.69" Tc=6.0 min CN=98 Runoff=3.64 cfs 0.204 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=1.110 ac 24.32% Impervious Runoff Depth>1.45" Tc=6.0 min CN=84 Runoff=2.77 cfs 0.134 of Pond 19P: SWM 3 Peak Elev=425.15' Storage=0.048 of Inflow=5.41 cfs 0.294 of Outflow=2.82 cfs 0.294 of Link 18L: Areas Combined Inflow=5.34 cfs 0.428 of Primary=5.34 cfs 0.428 of Total Runoff Area = 2.770 ac Runoff Volume = 0.428 of Average Runoff Depth = 1.86" 51.99% Pervious = 1.440 ac 48.01% Impervious = 1.330 ac Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 1.84 cfs @ 11.99 hrs, Volume= 0.091 af, Depth> 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.92" Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-3 (Offsite, detained) Hydrograph 2 1.84 cfs Type II 24-hr 1-Yr Rainfall=2.92" Runoff'Area=0.750 ac Runoff Volume=0.091 of Runoff Depth>1.45" Tc=7.0 min CN=84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 3.64 cfs @ 11.96 hrs, Volume= 0.204 af, Depth> 2.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.92" Area (ac) CN Description 0.660 98 Paved parking, HSG D 0.250 98 Paved parking, HSG D 0.910 98 Weighted Average 0.910 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Hydrograph a- C I I I I I I I I I I I I I I I I I 3- 2- Type II 24-hr .-- --1-Yr Rainfall=2.92" Runoff'Area=0.910 ac Runoff Volume=0.204 of Runoff Depth>2.69rr 11 12 13 14 Time (hours) Tc=6.0 min CN=98 ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 2.77 cfs @ 11.97 hrs, Volume= 0.134 af, Depth> 1.45" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Yr Rainfall=2.92" Area (ac) CN Description 0.270 98 Paved parking, HSG D 0.840 80 >75% Grass cover, Good, HSG D 1.110 84 Weighted Average 0.840 75.68% Pervious Area 0.270 24.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Hydrograph 2.7 ' i i i ❑ Runoff Type II 24-hr 1-Yr Rainfall=2.92" Runoff'Area=1.110 ac Runoff Volume=0.134 of Runoff Depth>1.45" Tc=6.0 min --- ---- -- ------EN=84 11 12 13 Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Pond 19P: SWM 3 Inflow Area = 1.660 ac, 63.86% Impervious, Inflow Depth > 2.13" for 1-Yr event Inflow = 5.41 cfs @ 11.97 hrs, Volume= 0.294 of Outflow = 2.82 cfs @ 12.07 hrs, Volume= 0.294 af, Atten= 48%, Lag= 6.0 min Primary = 2.82 cfs @ 12.07 hrs, Volume= 0.294 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 425.15' @ 12.07 hrs Surf.Area= 0.020 ac Storage= 0.048 of Plug -Flow detention time= 4.3 min calculated for 0.294 of (100% of inflow) Center -of -Mass det. time= 4.2 min ( 781.7 - 777.5 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 '/' Device Routing Invert Outlet Devices #1 Primary 422.00' 18.0" Round Culvert L= 50.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 422.00' / 420.00' S= 0.0400 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Primary 425.29' 30.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 426.70' 2.4' long Sharp -Crested Rectangular Weir 0 End Contraction(s) Primary OutFlow Max=2.80 cfs @ 12.07 hrs HW=425.1 T (Free Discharge) Culvert (Passes 2.80 cfs of 10.32 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.80 cfs @ 8.02 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Pond 19P: SWM 3 Hydrograph I~ _ ' 5.41 cfs I I I I 1 I I I _J _1 _L_..I I I I I 1 I I I I I I I 1 I I I I I I I I 1 I I I I I I I I I 1 I I I I I I I I I 1 I I I I I I I I I 1 I I I I I I I I I 1 I I I I I w y 1 3 2.$L oI I I I 1 I I I I I LL 1 -T -r T-1 -T -F I I I I 1 I I I I I 1 2- I I I I 1 I I I I I I I I I 1 I I I I I I I I 1 I I I I I _i_ r__r__ y__ 7__r__y_ I I 1 I I I I I I I 1 I I I I I I I I I I I I I I 11 12 13 Time (hours) Inflow Area=1.660 ac Peak Elev=425.15' Storage=0; 0 4$ of I I I I I I I r I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I T-1 -T -r -I -1 -T -r T--1 -T I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I _ y__7__r__y__r__r__y__ tLL __ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ❑ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-09Type 1124-hr 1-YrRainfall=2.92" Prepared by Timmons Group Printed 10/19/2020 Summary for Link 18L: Areas Combined Inflow Area = 2.770 ac, 48.01 % Impervious, Inflow Depth > 1.86" for 1-Yr event Inflow = 5.34 cfs @ 11.99 hrs, Volume= 0.428 of Primary = 5.34 cfs @ 11.99 hrs, Volume= 0.428 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 18L: Areas Combined I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I 5.3 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I q_ I I I I I I I I I I e I I I I I I I I I V I I I I I I I I I I 3- I I I I I I I I I I o I I I I I I I I I I LL I I I I I I I I I I I I I 1 I I r I -1 I I I I I I I I I I 1 2 I I I I I I I I I I I I I I I I i I 1 I I I I I I I I I � I I I I 1 I I I ■ Inflow ]'I ❑ Primary -Inflow Area=2.770 ac I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: Post Area 1-3 (Offsite, Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>1.97" Tc=7.0 min CN=84 Runoff=2.48 cfs 0.123 of Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=0.910 ac 100.00% Impervious Runoff Depth>3.30" Tc=6.0 min CN=98 Runoff=4.44 cfs 0.251 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=1.110 ac 24.32% Impervious Runoff Depth>1.97" Tc=6.0 min CN=84 Runoff=3.74 cfs 0.182 of Pond 19P: SWM 3 Peak Elev=425.71' Storage=0.059 of Inflow=6.83 cfs 0.374 of Outflow=5.24 cfs 0.373 of Link 18L: Areas Combined Inflow=7.66 cfs 0.556 of Primary=7.66 cfs 0.556 of Total Runoff Area = 2.770 ac Runoff Volume = 0.556 of Average Runoff Depth = 2.41" 51.99% Pervious = 1.440 ac 48.01% Impervious = 1.330 ac Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 2.48 cfs @ 11.98 hrs, Volume= 0.123 af, Depth> 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-3 (Offsite, detained) Hydrograph 2.48 cfs Type II 24-hr 2-YR Rainfall=3.54" 2 Runoff'Area=0.750 ac Runoff Volume=0.123 of Runoff Depth>1.97" Tc=7.0 min CN=84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 4.44 cfs @ 11.96 hrs, Volume= 0.251 af, Depth> 3.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 0.660 98 Paved parking, HSG D 0.250 98 Paved parking, HSG D 0.910 98 Weighted Average 0.910 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Hydrograph ❑ Runoff 4.44 I Type II 24-hr 2-YR Rainfall=3.54rr Runoff'Area=0.910 ac -Runoff Volume=0.251 of Runoff Depth>3.30rr i Tc=6.0 min QN=98 11 12 13 14 Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 3.74 cfs @ 11.97 hrs, Volume= 0.182 af, Depth> 1.97" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 0.270 98 Paved parking, HSG D 0.840 80 >75% Grass cover, Good, HSG D 1.110 84 Weighted Average 0.840 75.68% Pervious Area 0.270 24.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f /ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Hydrograph ^ 3.74 cfs Type II 24-hr 2-YR Rainfall=3.54rr 3 Runoff'Area=1.110 ac Runoff Volume=0.182 of Runoff Depth>1.97" 2 Tc=6.0 min CN=84 11 12 13 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Pond 19P: SWM 3 Inflow Area = 1.660 ac, 63.86% Impervious, Inflow Depth > 2.70" for 2-YR event Inflow = 6.83 cfs @ 11.97 hrs, Volume= 0.374 of Outflow = 5.24 cfs @ 12.05 hrs, Volume= 0.373 af, Atten= 23%, Lag= 4.6 min Primary = 5.24 cfs @ 12.05 hrs, Volume= 0.373 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 425.71' @ 12.05 hrs Surf.Area= 0.019 ac Storage= 0.059 of Plug -Flow detention time= 4.5 min calculated for 0.373 of (100% of inflow) Center -of -Mass det. time= 4.4 min ( 778.0 - 773.6 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 '/' Device Routing Invert Outlet Devices #1 Primary 422.00' 18.0" Round Culvert L= 50.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 422.00' / 420.00' S= 0.0400 T Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Primary 425.29' 30.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 426.70' 2.4' long Sharp -Crested Rectangular Weir 0 End Contraction(s) Primary OutFlow Max=5.15 cfs @ 12.05 hrs HW=425.69' (Free Discharge) Culvert (Passes 3.08 cfs of 11.53 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.08 cfs @ 8.83 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 2.06 cfs @ 2.04 fps) Keswick Hall_Spa_Analysis Points 1 (POST)_vE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Pond 19P: SWM 3 Hydrograph I I I I I I I I I I I I I I I __L1IIIIIIIIII _IIII'IIIIIIIIIIL _IIIIIIIIIIIIII_JIIIIIIIIIIIIII _IIIIIIIIIIIII IIIIIIIIIIIIIIII IIIIIIIIIIIIII III 6.8 ;-r --I1-4--I 5.24 I __ __ I _ I I I I I I I I L _ III I I I I I I I I II I I I I I I I I I I 1 I I I I I I I I I I I I I I I I 3 efs ; ;- - -I - - lnflow Area=1.,$ iat Poa';k F-lev=42¢.71' -III---�ibr�ge=D;CQ5�'I, afi - I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I --I- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I _I _J _L _L _I _J _L _L _I _J _L I I I I I I I I I I I I I I I I I I I I ! I I I I I I 5 6 7 8 9 10 11 12 13 Time (hours) ■ Inflow ■ Primary Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-0Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/19/2020 Summary for Link 18L: Areas Combined Inflow Area = 2.770 ac, 48.01 % Impervious, Inflow Depth > 2.41" for 2-YR event Inflow = 7.66 cfs @ 12.02 hrs, Volume= 0.556 of Primary = 7.66 cfs @ 12.02 hrs, Volume= 0.556 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Link 18L: Areas Combined /--I1--J--1--IL--I1--J--1--IL- '-- I -1n f k)W'I AreaF2.',7 I- 7 6 I I I I I I I I I I I I I I 1 I I I I I I I I I I I __J__L__L__L I I I I I I I I I I I I I I I I I I I I -r -I --I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ______I__ I______ 1_ I I_I I I I _ I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 1 0 Primary I I I I I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I __ I__L__ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -1 -T -F -I -1 -T -r -I -T -T I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Time span=0.00-24.00 hrs, dt=0.05 hrs, 481 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: Post Area 1-3 (Offsite, Runoff Area=0.750 ac 20.00% Impervious Runoff Depth>3.59" Tc=7.0 min CN=84 Runoff=4.42 cfs 0.224 of Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=0.910 ac 100.00% Impervious Runoff Depth>5.11" Tc=6.0 min CN=98 Runoff=6.74 cfs 0.387 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=1.110 ac 24.32% Impervious Runoff Depth>3.59" Tc=6.0 min CN=84 Runoff=6.67 cfs 0.332 of Pond 19P: SWM 3 Peak Elev=426.69' Storage=0.075 of Inflow=11.04 cfs 0.612 of Outflow=9.97 cfs 0.612 of Link 18L: Areas Combined Inflow=16.34 cfs 0.943 of Primary=16.34 cfs 0.943 of Total Runoff Area = 2.770 ac Runoff Volume = 0.944 of Average Runoff Depth = 4.09" 51.99% Pervious = 1.440 ac 48.01% Impervious = 1.330 ac Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 4.42 cfs @ 11.98 hrs, Volume= 0.224 af, Depth> 3.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Yr Rainfall=5.35 Area (ac) CN Description 0.150 98 Paved parking, HSG D 0.580 80 >75% Grass cover, Good, HSG D 0.020 77 Woods, Good, HSG D 0.750 84 Weighted Average 0.600 80.00% Pervious Area 0.150 20.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-3 (Offsite, detained) Hydrograph 4.42 cfs Type II 24-hr 4 10-Yr Rainfall=5.�35" Runoff'Area=0.750 ac 3- Runoff Volume=0.224 of I Runoff Depth>3.59" Tc=7.0 min 2 CNy84 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 6.74 cfs @ 11.96 hrs, Volume= 0.387 af, Depth> 5.11" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Yr Rainfall=5.35" Area (ac) CN Description 0.660 98 Paved parking, HSG D 0.250 98 Paved parking, HSG D 0.910 98 Weighted Average 0.910 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Hydrograph 4 � 6 I I I I I I I I I I I I I I I I I I V4 I I i O I I I 3 I I I I I I I 2 I I I I I I -r r Type II 24-hr 10-Yr Rainfall=5.35" Runoff'Area=0.910 ac Runoff Volume=0.387 of Runoff Depth>5.11 rr Tc=6.0 min QN=98 I I 11 12 13 14 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 6.67 cfs @ 11.97 hrs, Volume= 0.332 af, Depth> 3.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Yr Rainfall=5.35 Area (ac) CN Description 0.270 98 Paved parking, HSG D 0.840 80 >75% Grass cover, Good, HSG D 1.110 84 Weighted Average 0.840 75.68% Pervious Area 0.270 24.32% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (f /ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Hydrograph I I I I I 6.6 I I I I I 7 cfs I I I I I I I I I I I I I I I I I I I I I I I 6 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 5 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 I I I I I I I 3- I I I I I I I I I I I I I I I I I I I I I I I I 2- I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I Type II 24-hr 10-Yr Rainfall=5.35rr Runoff Area=1.110 ac I I IRdn60Vo1ume=0.332 of Runoff Depth>3.59" Tc=6.0 min CN=84 11 12 13 14 Time (hours) ❑ Runoff Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Summary for Pond 19P: SWM 3 Inflow Area = 1.660 ac, 63.86% Impervious, Inflow Depth > 4.42" for 10-Yr event Inflow = 11.04 cfs @ 11.97 hrs, Volume= 0.612 of Outflow = 9.97 cfs @ 12.01 hrs, Volume= 0.612 af, Atten= 10%, Lag= 2.3 min Primary = 9.97 cfs @ 12.01 hrs, Volume= 0.612 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 426.69' @ 12.01 hrs Surf.Area= 0.013 ac Storage= 0.075 of Plug -Flow detention time= 4.2 min calculated for 0.610 of (100% of inflow) Center -of -Mass det. time= 4.1 min ( 769.3 - 765.2 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 '/' Device Routing Invert Outlet Devices #1 Primary 422.00' 18.0" Round Culvert L= 50.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 422.00' / 420.00' S= 0.0400 '/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 8.0" Vert. Orifice/Grate C= 0.600 #3 Primary 425.29' 30.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 426.70' 2.4' long Sharp -Crested Rectangular Weir 0 End Contraction(s) Primary OutFlow Max=9.84 cfs @ 12.01 hrs HW=426.66' (Free Discharge) Culvert (Passes 3.49 cfs of 13.28 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.49 cfs @ 10.01 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 6.34 cfs @ 5.07 fps) Keswick Hall_Spa_Analysis Points 1 (POST)_VE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 Pond 19P: SWM 3 Hydrograph I I I I I I I 1 I I I 1 I I I I I � Inflow 1 12 ____ __7__r__,___,__7__.r __. 11.04 cfS--r-7--T--r------r-r--r �__ ■Primary 11:, 9.97 cfs IDI �p��y //�y/�� ./y�I ,Q -I -4 -i -Y -I -I -Y -Y -r -I I I I I I I I i I I �� I I I I I I I I -I I I /I\�`i I I I 75, af- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I �j ] V I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I 6 __,__"--i--Y--I---I--i--Y--- --__,__y__*--Y------i--Y----I-- o I I I I I I i I I I I I I I I I LL ------------- I I I I I I I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 2 -I _a _y _ti _I _I _i _4 _I _y _F _I _� _♦ _F _I _y _y _ti _F _I i I I i I I I I I I I I I I I I I i i i I I I I I 1 I I I I I Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST)YE 2020-OType 1124-hr 10-YrRainfall=5.35" Prepared by Timmons Group Printed 10/19/2020 U-A—OAM( An nn on aI- n0nn4 (, On17 n--- nC Summary for Link 18L: Areas Combined Inflow Area = 2.770 ac, 48.01 % Impervious, Inflow Depth > 4.09" for 10-Yr event Inflow = 16.34 cfs @ 11.99 hrs, Volume= 0.943 of Primary = 16.34 cfs @ 11.99 hrs, Volume= 0.943 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs 1 t 1 3 O LL Link 18L: Areas Combined --- ; ;- - ;- -- I I I I I I I --I---- --I --�------I - 16. I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I / I I I I I I I I I I I I I I I I I / I I I I I I I I I i I I I I I I I I / I / I I I I I I I I I I I I I I I I -I- 1 / I -1 -T -r I / I -1 -T -!" -I -I -T / I -I -1 -T -r -I I / I -Y -Y -I -I -T -Y -I -y I I I I I I I I I / I I _I _T _T _Y _1 _I _T _t _1 _y I I I I I I I I ■ Inflow ❑ Primary S4 cfs Inflow Area-2 770 ac I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I _r _I _1 _T _r _I _1 _T _r _r _I I I I I I I I I I I I I I I I I I I I I I I I I __r__I__y__T__r__I__y__ f__r__r__I__ I I I I I I I I I I I -F _I _y _♦ _F _I _y -i -h _F y I I I I I I I I I I I I I I I I I I I i 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) COBON011 Chesapeake Bay Nutrient Land Trust, LLC. January 26, 2018 Mr. Andrew Allison Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 RE: CBNLT / Oak Grove — Nutrient Credit Availability Project Reference: Keswick Hall and Golf Club Attention: Mr. Allison: "Tomorrows Natural Resources Today" This letter is to confirm the availability of authorized Nutrient Credits sufficient to meet your project requirements at our Oak Grove nutrient facility, which is registered with the Virginia Department of Environmental Quality (DEQ). These Nutrient Credits are generated and managed under the terms of the Oak Grove Nutrient Reduction Implementation Plan dated May 11, 2017 which was authorized by the DEQ on August 31, 2017. The Oak Grove project has been authorized to provide Nutrient Credits for use in the James River watershed. These Credits are transferable to those entities regulated under DEQ's Stormwater Management Program in accordance with VA Code § 611-44.15:35. Currently our Oak Grove facility has 38_16 pounds of Phosphorus Credits available. If we can provide further assistance please feel free to contact our office. Sincerely, Chesapeake Bay Nutrient Land Trust, LLC By Its Manager EarthSource Solutions, Inc. Scott A. Reed Vice President Chesapeake Bay Nutrient Land Trust, LLC. • 5735 S. Laburnum Avenue • Richmond, VA 23231 • P: 804.222.5114 • www.cbnit.com