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HomeMy WebLinkAboutSUB202100079 Calculations 2021-12-21Southwood Redevelopment — Blocks 11&12 ALBEMARLE COUNTY, VIRGINIA WPO PLAN DESIGN CALCULATIONS & NARRATIVE APRIL 12, 2021 REV. AUGUST 20, 2021 REV. DECEMBER 17, 2021 • TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Bryan Cichocki, PE Timmons Group 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 434.327.5380 D. Cichodd Lic. No. 53741 1W///to Table of Contents Section Title 1. Project Narrative 2. LD-204 Inlet Calculations 3. LD-229 Pipe Calculations 4. LD-347 Hydraulic Grade Line Analysis 5. Virginia Runoff Reduction Method Worksheet Summary Project Narrative: This project includes the construction of one private road, three apartment buildings, and associated parking, utilities, and landscaping. The limits of disturbance is 4.11 acres. Water Ouality: The current site is undeveloped. 4.11 total acres were analyzed for water quality, which was further broken down into Blocks 11 and 12. Block 11: In the existing condition, block 11 is made up of 1.27 acres of managed turf. In the proposed condition, the landcovers will be 0.43 acres of managed turf and 0.84 acres of impervious cover. The total TP load reduction required is 1.50 lbs/year. 0.66 lbs/year will be treated by a level 2 bioretention facility. The remaining 0.84 lbs/yr of required nutrient credits area shall be purchased from a DEQ-Approved Nutrient Credit Bank in Accordance with VA code 62.1-44.15:35. Block 12: In the existing condition, block 12 is made up of 2.84 acres of managed turf. In the proposed condition, the landcovers will be 0.88 acres of managed turf and 1.96 acres of impervious cover. The total TP load reduction required is 3.48 lbs/year. 2.70 lbs/year will be treated by a combination of a level 2 bioretention facility, a manufactured filtering device, and a manufactured hydrodynamic device. The remaining 0.78 lbs/yr of required nutrient credits area shall be purchased from a DEQ-Approved Nutrient Credit Bank in Accordance with VA code 62.1-44.15:35. Water Quantity Water quantity requirements for this site will be met through a stormwater pond constructed per WPO201900062. No additional stormwater quantity measures are proposed with this plan. FORM L0201 STORMWATER INLET COMPUTATIONS SHEET 1 OF ROU PROJECT $gNm'pJp_BbCk 11 DESIGNER: NWA OATS NW2021 CHECKED: UNITS UGLIER INLEfSOFT BY ENSOFTEC DATE 89 ul FORM L0201 STORMWATER INLET COMPUTATIONS SHEET 1 OF ROU PROJECT SO S.011-Bb 12 DESIGNER: NWA OATS NW2021 CHECKED: UNITS UGLIER �mm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�®®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmm®mmmmmmmm®mmmmmmmm®m® mmm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomommmmm®m®m®mmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmammmmmm��®m® �mm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomom�mmmmm®m®mmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmammmmmm��®®® ®mm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomom�mmm�m®m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmm®mm®®®® mmm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomom��mm�m�m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmmmmmm®®® mmm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmo�ommmmmmmmmmmmm■■mmmmmmm��m mmm�mmmmmmm�mmmmmmmmmmmmomm�mmmm�mtm® ®mm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmomom�mmm�mmm®mmmm®mmm�mm��m� ®mm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmm�o�om�mmm�m®m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmmmm�®®®® mmm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmo�ommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmm�mmm®mmmmmmmmomm�mmmm�mtm® mm®�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmm®mmmmmmmm®mmmmmmm�mtm INLEfSOFT BY ENSOFTEC DATE: B9 Ul PHA Block 77 Storm STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 70 PROJECT: LOCATION: COUNTY: Designed by: Checked by: UNITS ENGLISH PIPE NO FROM PONT TO POINT DRAM. AREA "A" Acre (3) RUNOFF COEFF. "C" (A) CA TOTAL INLET TIME Minutes (]) RAIN FALL IN (8) RUNOFF Q CFS (9) MVERTELEVATIONS LENGTH of Pipe Ft (12) SLOPE F(N( (13) SIZE (Di. Or SpaNRise) In. (IA) SHAPE Capacity US (15) Friction $lope Ft/Ft. VEL V. FVSm (16) FLOW TIME Min. (17) REMARKS (18) MCR� MENT (5) ACCUM- ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (I) STA. REFERENCE (2) STA. 203 20a 202 0000 0000 0000 0333 0333 6000 6230 2075 a]A.183 a]03a2 $0018 ONS 15.000 Ci¢ular 15328 0001 8740 0.153 Areafrom RD1 205 206 202 0"0 0]00 0308 0308 0000 60M 6230 1919 470600 470350 42.974 0006 12.000 Ciculsr 2.9C3 0002 4001 0.1]9 PHA BLOCK 12 STORM STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 10 PROJECT: LOCATION: COUNTY: Designed by: Checked by: UNITS ENGLISX PIPE NO FROM POINT TO POINT DRAM. AREA RUNOFF COEFF. C. (A) CA TOTAL MLET TIME Minutes (3) RAM FALL RVHr (8) RUNOFF Q CPS (9) MVERTELEVATIONS LENGTH of Pipe Ft (12) SLOPE FtIF1. (13) SIZE Uka Cc SpanM-) In. (IA) SHAPE Capariry CHFI/Ft (15) Fnclion SIope VEL V. PON. (16) FLOW TIME M. (17) REMARKS Us) MCRE-ACCUM- MENI (5) ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. "A' Acre (3) 119 120 RD2 0.150 0.350 0053 0053 0000 6000 6230 0327 688362 488.239 26652 0005 12W CircWsr 2MS 0000 ZM7 0.195 RD1 RD2 Us 0000 0000 0000 0053 0.000 6-175 6.179 0324 488.140 487 660 62922 0008 12W CircWsr 3.390 0000 2319 0.386 119C 118 II]R 0000 0000 0000 0359 0.306 6561 6070 2.176 497556 486480 71713 0015 15000 CircWsr 8.568 0001 SW 0205 Area from RD1 117A 119R 116 0A60 0.820 0377 0936 0.000 6765 6014 6624 486.383 486237 16563 0010 15000 CircWsr 6.996 OON 6.065 ONO 129 128 116 0SOO O780 0390 0390 0.000 6000 6230 2430 436.436 486310 25.158 0005 15W C'mwar 4M9 0001 4.022 0.1M Us 116 114 0000 0000 0000 1126 0000 6805 6003 6957 485.817 485360 91483 0005 18000 CircWsr 8045 OON SA13 0298 113 IIA 112 0000 0000 0000 1396 0270 7_104 5923 8267 485258 485.M0 43553 0005 21000 CircWsr 12.136 0002 S.A39 0.133 Area from RD2 111 112 110 0000 0000 0000 1396 0000 7237 5.889 8219 4N.940 484.S0 76039 0005 21000 CircWsr 12.136 0002 S.A32 0229 133 13A 132 0.160 0990 0.126 0.126 0000 6000 6230 0987 486.380 485A75 50232 0010 15000 CircWsr 7012 0000 3988 02L 131 132 110 0.150 0.350 0053 0179 0000 6221 6.166 1103 48534) 484570 67614 0010 21000 CircWsr 19.163 0000 4.O14 0281 107 110 106 0.180 0990 0.139 1713 0000 70 5.831 9989 4N.466 484400 13219 0005 21000 CircWar 12.136 0003 56A7 0039 105 106 104 0000 0000 0000 1713 0000 7503 5.821 9972 AN197 484_193 20682 0.005 21000 CircWar 12.136 0003 56A5 0061 1N IN 103 0210 0690 0.145 1.858 0000 7W 5.805 10787 4N.088 483080 202268 0.005 21000 CircWar 12.119 OON 5/08 0.591 102 103 102 0000 0000 0000 1.858 0000 8.155 5662 10521 482979 482570 82580 0.005 21000 C,md. 12083 OON 5674 0N3 @I III 102 00in 0.900 0009 0009 0000 0000 8901 0080 A86.A56 A85856 3001A 0.020 15000 CircWar 9.89A 0000 2A33 0206 101 102 60 0030 0.9'!0 0023 1.890 0.000 8.398 5605 10595 4824)2 482310 32A❑ 0.005 21000 CircWar 12.136 OON 5700 1 0095 PHA Black 11 Stoml PROJECT: DESIGNED BY: HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INLET INLET OUTLET WATER OIA PIPE DESIGN DISCH. LENGTH PIPE FRICTION SLOPE FRICTION LOSS JUNCTION LOSS FINAL IFYI Waled M. COInMn6 1.3 05 OR STATION SURFACE DO Q. LO M - Ho pl Vi QM V14118 HI Angle HA HI HI HI H Sums Ekv JUNCTION EIEV. (In) ICES) (Ft) (FTIFT) (Ft) OF (M) EI.U. 204 1 10+80.39 1 471.34 1 15 2.07 $0.02 0.09% 0.07 8.74 0.3 0 0 0 0 0 0 0 0.3 0 TRUE 0.22 471.56 PHA BLOCK 12 STORM PROJECT: DESIGNED BY: HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION INLET STATION OUTLET NMTER SURFACE ELEV. CIA PIPE Do (In) DESIGN OISGH. Oo (GFS) LENGTH PIPE Ln (Ft) FRICTION SLOPE, SIo (FTIM FRICTION LOSS M (Ft) JUNCTION LOSS FINAL H TO It W r SuU E1.11. RM Ek GOnm¢nb VO Ho (Ft) OI M OM M-2a, HI An* HA HI 1.3 HI JS HI 102 10 33.7 483.71 21 10.6 32.42 0.38% 0.12 5.7 0.13 10.52 5.67 59.69 0.5 0.17 22.18 0.12 0.43 0 TRUE 0.34 484.05 493.32 OK -9.28 103 484.05 21 10.52 82.58 0.38% 0.31 5.67 0.12 10.79 5.71 61.57 0.51 0.18 15.22 0.1 0.4 0 TRUE 0.51 484.56 493.16 OK -8.6 104 13+18.12 484.56 21 10.79 202.27 0.39% 0.8 5.71 0.13 9.97 5.65 56.3 0.49 0.17 84.86 0.33 0.63 0 TRUE 1.11 485.67 490.93 OK -5.7 106 13+38.80 485.67 21 9.97 20.68 0.34% 0.07 5.65 0.12 9.99 5.65 56.41 0.5 0.17 87.84 0.35 0.64 0 TRUE 0.39 486.06 492.26 OK -6.2 110 13+52.02 486.06 21 9.99 13.22 0.34% 0.D4 5.65 0.12 8.22 5.43 44.65 0.46 0.16 91 0.32 0.6 0 TRUE 0.35 486.41 491.9 OK -5.49 112 14+26.06 486.41 21 8.22 74.04 0.23% 0.17 5.43 0.11 8.27 5.44 44.97 0.46 0.16 79.63 0.3 0.58 0 TRUE 0.46 486.87 492.76 OK -5.89 114 14+69.73 486.87 21 8.27 43.55 0.23% 0.1 5.44 0.11 6.76 5.11 34.55 0.41 0.14 30.87 0.14 0.4 0 TRUE 0.3 487.17 492.82 OK -5.66 116 15+61.21 487.17 18 6.76 91.48 0.35% 0.32 5.11 0.1 4.42 6.05 26.75 0.57 0.2 96.99 0.18 0.48 0 TRUE 0.56 487.73 490.89 OK -3.16 117B 15 75.78 487.73 15 4.42 14.56 0.40% 0.06 6.05 0.14 2.18 5.84 12.71 0.53 0.19 11.2 0.07 0.4 0.52 TRUE 0.32 488.04 491.01 OK -2.97 118 16+47.49 488.04 15 2.18 71.71 0.10% 0.07 5.84 0.13 0.32 2.T2 0.88 0.11 0.04 75.45 0.08 0.25 0 TRUE 0.19 488.24 492.84 OK 4.61 RD2 17+10.74 488.46 12 0.32 62.92 0.01% 0 2.72 0.03 0.33 2.35 0.n 0.09 0.03 44.49 0.04 0.1 0 FALSE 0.1 488.56 492.93 OK 4.37 120 17+35.39 489.04 12 0.33 24.65 0.01% 0 2.35 0.02 0 0 0 0 0 0 0 0.02 0.03 TRUE 0.02 489.05 492.21 OK -3.15 122 10 30.38 486.86 15 0.08 30.01 0.00% 0 2.43 0.02 0 0 0 0 0 0 0 0.02 0.03 TRUE 0.01 486.87 493.09 OK -6.22 132 10 69.87 486.41 21 1.1 69.87 0.00% 0 4.01 0.06 0.79 3.78 2.98 0.22 0.08 89.86 0.16 0.3 0.38 TRUE 0.2 486.6 491.91 OK -5.3 134 486.87 15 0.79 50.47 0.01% 0.01 3.T8 0.06 0 0 0 0 0 0 0 0.06 0.07 TRUE 0.D4 486.92 490.88 OK -3.96 128 10«29.09 487.73 15 2.43 25.16 0.12% 0.03 4.02 0.06 0 0 0 0 0 0 0 0.06 0.08 FALSE 0.11 487.84 489.83 OK -1.99 �00��0��0� ■ �QO_�0�� 0■�0� 000��o�©v�oo. ■-■�,-■1 0 Drainage Area A Drainage Area Aland Cover (acres) Total D.. Stormwater Best Management Practices (RR = Runoff Reduction) Total Phoommus Available for Remoal In D.A. A(Ib/yr) Baf Port Development Trcxment Volume In D.A. A(N) 1�3 —select from ampaown Ham — P!a[t [! Runoff Reduttlon CredN (%) ManyeG CredN Arco Area(anes) ImpeMws Cover CreeN Arco (acres) Volume term Runoff UP[Veam ReduNon(Na)RuroXValume prattle (f�) Remouns, (fta) Totl BMP Trea4rem Valume(Na) PMspM1mus Rennusl nndenry)%) XwspM1ws Wd Untreated floor Uprtream PW PpMm5 Wd prettlar (Ih) WPn[tlre (lb) Plnaphoms Rennued By Practice (Ih) Remaining pM1OSp(lb) Wad (lb) pow,nVeadered eWhe Employed z. Vegeuree nmlmlkea asl I,re- e. Venom. Was. per AD I, - - xa.vmgeokamnx,bn,eaesdh IkeapU se e vmge d ("Par mim m e/owe Ikeaq apemlon+a laavu a Wexeyx, (keaw) aearn aa1sma ael mu4 .lam nn lsoea In, cal, -n—sence aysm, am a All—tes H111uJ19lkea AD mn(5amem�Mpewenl ,. mmea a.amamm(waadn mea a a.anamaB(Seaapn ,. ,aai m.aladwenpadd) ,aai nnaltJowelYeam) D, Tampmtnmmdadwli o�Ican Raam) :.ndysnalemlYeamB) R�! cnmaml _dn,nm,eral.1-iade,naae, Rw,admamR ,.. ,a mm(wmNd) n n nnnpeaul =711Donfl= eaaassl ."an Removal miclenry I%) XNmgen Wad from UPSbeam Practices(Ihs) U.d F!"an Wad to Prattlm(lbs) ."on Reversed By Practice(lbs) Remaining admgen Wad ran) to s aR NH u, Isce,.zle. - sn ,d.vDsem. ,a lsPn.zl� - N-rN. to Fmm Nro, n sa6 a, e.e MVD:vI. �GN,R, so a D D o D nm am Dm nm AMI TOTAL IMPERVIOUS COVER MATEOIa[) D.}B AREACNECN: OK. TOTAL MANAGED TURF AREA TREATEOIa[) D.16 ARFACNEER: OR. TOTAL RUNOFF REDUCTION IN DA A(Re) 8SS TOTAL PHOSPHORUS AVAP PULE FOR REMOVAIN D.A.A::,11 ) 0F3 TOTAL PHOSPHORUS REMOVED WRN RUNOFF REDUCTION PMRNES IN D.A. A(IR/y�) D.M TOTAL PHOSPHORUS REMAINING AMR APPLYING RUNOFF REDUCTION PRACRICES IN D.A. A HWr) OD) SEE WATER QUALITY COMPLMNCE TAB FOR SIT£ COMPLIANCE CALCULATIONS TOTALIMPERHOUSCOVERTREATED)a[) D.}B AREACNECK: OK. TOTAL MANAGED TURF AREA TREATED LIC) O.m6 AREACHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE)IE/,o) LSO TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A)IL/,o) O6R TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PMCTICES IN D.A. A)I!/yl) OOS TOTAL PHOSPHORUS REMOVED WITH RUNOFF REOUCl10N PRACTICES I N D.A. A)IN/to O61 TOTAL PHOSPHORUS LOADREDUCFION ACHIEVED IN DA A R!/yC) OM TOTAL PHOSPHORUS REMAINING AFTER APPLYING RMP MAD REDUCTIONS IN D.A. A) IL/r) O.@ s. meemo. to FIUe,/OAee Sta[e IRA TOTAL RU NOFF REDUCTION IN D.A A(W) 865 MR-11. REMWEDWT. RUNOFF REDUCTION PMCIICES INDA.AjIb/r)j 647 SEE WATER QUALITY COMPLMNCE Ml FOR 511E CAECULAHHONS (Infoimofion Only) IS 707, SEE WATER QUALI" COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMWED WRN RUN.lF REDUC]IOX PMCMES IX D.P. PLIL/yII AO] NITROGEN REMWED WLINDUT RUN., REDUC]IOX PMClICE51N D.P. RLIR/yA AT TOTRL NITROGEN REMOVED IN D.R. R(IN/W) AO] Virginia Runoff Reduction Method Workshest DEC, Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Droll Stds & Specs Site Summary Project Title: Southwood - Block 11 Date: 44428 Total Rainfall (in): 43 Total Disturbed Acreage: 1.27 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) Asoils BSolis [Soils DSolis Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 1 1.27 0.00 0.00 1.27 100 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 1.27 100 Post-ReDevelopment Land Cover (acres) Asoils BSoils CSGIls DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 1 0.00 0.43 0.00 0.00 0.43 34 Impervious Cover (acres) 1 0.00 0.84 0.00 0.00 0.84 66 1.27 100 Site Tv and Land Cover Nutrient Loads Final Port -Development Post- post- Adjusted Pre- (Post-ReDevelopment ReDevelopment Developmentrvlous ReDevelopment &New Impervious) ) (New Impervious) Site Rv 0.70 0.20 0.95 0.20 Treatment Volume(ft) 3,209 312 2,897 312 TP Load(lb/yr) 2.02 0.20 1.82 0.20 Baseline TP Load(lb/yr): 0.1763- 'Redaction below new aeM Parent kind limitation not required Total TP Load Reduction Required (lb/yr) 1.50 0.02 1.48 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (Ib/yr) 14.42 4.14 Pre- ReDevelopment Final Post -Development Post-ReDevelopment TP TP Load per acre TP Load per acre Load per acre (lb/acre/yr) (lb/acre/yr) (lb/acre/yr) 0.46 1.59 0.46 Summary Print Virginia Runoff Reduction Method Woftheet Site Compliance Summary Maximum% Reduction Required Below m% 'Note:% Reduction will reduce post- development TP load to less than or equal to baseline load of0.18lb/yr(0.41 lb/ac/yr) Pre-ReDevelopment Loatl (Required reducdonfom Post-RCDay.=Post-ReDev TP load -baseline load of0.17631b/yr), baseline load=site area x 0.41 lb/ac/yr Total Runoff Volume Reduction (k') 86S Total TP Load Reduction Achieved (lb/yr) 0.66 Total TN Load Reduction Achieved (lb/yr) 4.47 Remaining Post Development TP Load 1.36 (lb/yr) Remaining TP Load Reduction (Ib/yr) 0.94 Required 'Reduama below new development load limitation not required Summary Print Virginia Runoff Retlucfion Method Woftheet Drainage Area Summary DA. 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(acros) 0.16 0.00 0.00 0.00 0.00 0.16 Impervious Corer(acres) 0.28 0.00 0.00 0.00 0.00 0.28 Total Area (acres) 0.44 0.00 0.00 0.00 0.00 0.44 Drainage Area Compliance Summary DA. A D.A. B DA. C D.A. D D.A. E Total TP Load Reduced (lb/yr) 0.66 0.00 1 0.00 1 0.00 0.00 0.66 TN Load Reduced (lb/yr) 4.47 0.00 1 0.00 1 0.00 0.00 4.47 Summary Print Virginia Runoff Redasion Method Worksheet ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event (in) 1 3.04 3.68 5.57 Drainage Areas RV & CN Drainage Area A Drainage Area R Drainage Area C Drainage Area D Drainage Area E CN 85 0 0 0 0 RR (fta) 865 0 0 0 0 I -year return period RV wo RR (.,,-In) 1.62 0.00 0.00 0.00 0.00 RV w RR(wsin) 1.08 0.00 0.00 0.00 0.00 CN ad)urted 77 0 0 0 0 2-year return period RVwo RR(wzin) 2.17 0.00 0.00 0.00 0.00 RV w RR (wiAn) 1.63 0.00 0.00 0.00 0.00 CN adjusted! 78 0 0 0 0 10-year return period RV wo RR(ws-in) 3.90 0.00 OAO 0.00 0.00 RV w RR(wiAn) 3.36 0.00 0.00 0.00 0.00 CN adjusted 80 0 0 0 0 Summary Print 000��o�©v�oo. ■-■�,-■1 m Drainage Area A DralnaReAreaAWnd Cover (acres) lareampar ampare—laMn'.c., CAR Total 2.26 Stormwater Best Management Practices (RR = Runoff Reduction) Total PRospbomeMailable for Removal In D.A. A Batty) 39D Port Development Treatment Volume In DA A(W) 6E16 —select from ampaoem 1156— Plan [! Runoff Reduttlon CredN(%) Man,.d TurfCredN Arco (acres) ImpeMws CoverCredN Arco (acres) Volume from IlpsVeam Runoff ReduNon (Na) prounce w') RemalnRp RuroXValum, (Na) Totl BMP Trea4rem Valum,(ft) PMlh— n Renval Mcienryl%) MwspRws WG UnNeateO homllprtream lahmmorus Wd heatim ID) WPractice (lb) PMWh.rvs Renamed By Practice BID) Remaining PRospNoms Wad (Ib) downsfor—Pram,r,Aa Ne Employed z. Vegeureenm."Stea AD e. Vageu..A,)dace as) I, - - xa.vmgeokamnx,bn,eaesaN I"Doctm Ww x cvmgedie/oe (Zaa kaaq w Madnr+a laam aCSSe.dl(Star, ad) lm u4 a111, ml amp dc an (spar, Mel nykanl an1(kanl a All—te H111uJ19 Vraar c) mn(5aaea3�Mowm,nl ,. amea a.amamm(vam ,mea a P1111osaz(soa97) ,. ,aaa a..alaewenoaMsl ,ace. nndcrowe(zp,r,m) D, Tanproteeadadwla lase See., ,..C,Sealaarrspaacdyl s.mdysesis.rp,r,mn Be 0 So mar e.(:�.) _Ma,aa„e.11 mce-loan—un xtss a ,..1affilb,acen4.(wa,ae) llfl ulds,ag Spar, an Dmilosso ."an Removal EHcirms,(%) Vaal W. from UpS am Practices(Ibs) Il.d N"an Wad to Prattice(Ibs) ."on Rennved By Practice(lbs) Remaining Narogen Wad pas) to .LIrosR15I s aR ae u, Isce,.zl�� - sn ,a TSPn.zla - FS., Nro, n sNH a, e.e MVD:vI. �rsPKV so a D D o D nm aAt Dm nm FM, TOTAL IMPERVIOUS COVER TREATED )a[) D.39 AREACNECN: DR. TOTAL MANAGED MET AREA TREATE�).C) D.II ARFACNEER: OR. TOTAL RUNOFF REDUCTION IN DA A)R?) E�159 TOTAL PHOSPHORUS AVAP ARLE FOR REMOVAL IN D.A.A)M/y�) 390 TOTAL PHOSPHORUS REMOVED WRN RUNOFF REDUCTION PRACTICTS IN D.A. A)IL/y,) 5.38 TOTAL PHOSPHORUS REMAINING AMR APPLYING RUNOFF REDUCTION PRACTICES IN D.A. A) Wr) 25J SEE WATER QUALITY COMPLMNCE TAB FOR SIT£ COMPLIANCE CALCULATIONS TOTAL IMPERVIOUS COVER TREATED).[) I.GJ AREACNECR: OR. TOTALMANAGEDWREA FARTREATED).C) 0.53 AREACNECR: OR. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE)IE/,o) 3G8 TOTAL PHOSPHORUS AVAHARLE FOR REMOVAL IN D.A. A)IL/,o) 390 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PMCTICES IN D.A. A)I!/y,) L.3J TOTAL PHOSPHORUS REMOVED WITH RUNOFF REOUCl10N PRACTICES N D.A. A)I!/y,) 1.3R TOTAL PHOSPHORUS LOADREDUCFION ACHIEVED IN DA A(IWy,) J.JO TOTAL PHOSPHORUS REMAINING AFTER APPLYING RMP MAD REDUCTIONS IN D.A. A) IL/r) l.Jl 9. Seeemo. to FIUe,/OAee soda IRA TOTAL RU NOFF REDUCTION IN D.A A(wl J159 NITROGEN REMWEO INT. RUNOFF REDUCTION PMCIICES IND.AA(I!/y,) 11.15 SEE WATER QUALIFY COMPLMNCE TAN FOR SITE CALCULATIONS(Infoimofion Only) 25 77-- SEE WATER QUALI" COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMWED WRN RUN.lF REDUCiIDX PMCMES IN D.P. PIIY/yII 11.15 NITROGEN REMWED WLINDUT RUN., REDUCiIDX PMClICE51N D.P. RIIR/y�I D.DI TOTRL NITROGEN REMOVED IN D.R. R (IN/M) 11.15 Site ulta(Water Quality Compliance) Area LM1x am lay w nlay nMe or uyyMe or aMa TwaMwitt VMumelR°I tie RunoR MJuaim Volume and TP By P'aWRe Area m lx'I wm ONnI ne l�xMl u%u l�xMl TotalP Ihlns mao0Yn1 re am ONnI OY l- em l�xMt Total MWogan lau lrl rm4un Puryme[I maolVvrl tno l�xMl mm ObM Virginia Runoff Recursion Method Workshest DEC, Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Droll Stds & Specs Site Summary Project Title: Southwood - Block 12 Date: 44428 Total Rainfall (in): 43 Total Disturbed Acreage: 2.84 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) Asoils BSolls [Soils DSolis Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 1 2.84 0.00 0.00 2.84 100 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 2.84 100 Post-ReDevelopment Land Cover (acres) Asoils BSoils CSolls DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 1 0.00 0.88 0.00 0.00 0.88 31 Impervious Cover (acres) 1 0.00 1.96 0.00 0.00 1.96 69 2.84 100 Site Tv and Land Cover Nutrient Loads Final Port -Development Post- poll - Adjusted Pre- (Post-ReDevelopment ReDevelopmem Developmentrvlous ReDevelopment &New Impervious) ) (New Impervious) Site Rv 0.72 0.20 0.95 0.20 Treatment Volume(ft) 7,398 639 6,759 639 TP Load(lb/yr) 4.65 0.40 4.25 0.40 Baseline TP Load(lb/yr): 0.3608--Rrmmoa aeknu aew IeMPnrentkind rmitatioa not required Total TP Load Reduction Required (lb/yr) 3.48 0.04 3.44 Final Post-Developmem Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (Ib/yr) 33.25 9.27 Pre- ReDevelopment Final Post -Development Post-ReDevelopment TP TP Load per acre TP Load per acre Load per acre (lb/acre/yr) (lb/acre/yr) (lb/acre/yr) 0.46 1.64 0.46 Summary Print Virginia Runoff Reduction Method Woftheet Site Compliance Summary Maximum% Reduction Required Below 20% 'Note:% Reduction will reduce post- development TP load to less than or equal to baseline load of0361b/yr(0.41 lb/ac/yr) Pre-ReDevelopment Loatl (Required reducdonfom Post-RCDay.=Post-ReDev TP load -baseline load of0.360R Ib/yr), baseline load=site area x 0.41 lb/ac/yr Total Runoff Volume Reduction (kt) 2,159 Total TP Load Reduction Achieved (lb/yr) 2.70 Total TN Load Reduction Achieved (lb/yr) 11.15 Remaining Post Development TP Load 1.95 (lb/yr) Remaining TP Load Reduction (Ib/yr) 0.79 Required 'Reduama below new development load limitation not required Summary Print Virginia Runoff RecJalion Method Woftheet 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(acros) 0.58 0.00 0.00 0.00 0.00 0.58 Impervious Corer(acres) 1.68 0.00 0.00 0.00 0.00 1.68 Total Area (acres) 2.26 0.00 0.00 0.00 0.00 2.26 Drainage Area Compliance Summary DA. A D.A. B DA. C D.A. D D.A. E Total TP Load Reduced (lb/yr) 2.70 0.00 1 0.00 1 0.00 0.00 2.70 TN Load Reduced (lb/yr) 11.15 0.00 1 0.00 1 0.00 0.00 11.15 Summary Print Virginia Runoff Reduction Method Worksheet ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event (in) 1 3.04 3.68 5.57 Drainage Areas RV & CN Drainage Area A Drainage Area R Drainage Area C Drainage Area D Drainage Area E CN 89 0 0 0 0 RR (fta) 2,159 0 0 0 0 I -year return period RV wa RR(wzin) 1.94 0.00 0.00 0.00 0.00 RV w RR(ws-in) 1.67 0.00 0.00 0.00 0.00 CN ad(urted 86 0 0 0 0 2-year return period RVwo RR(wzin) 2.52 0.00 0.00 0.00 0.00 RV w RR (wsan) 2.26 0.00 0.00 0.00 0.00 CN adjusted 86 0 0 0 0 10-year return period RV wo RR(ws-in) 4.32 0.00 0.00 0.00 0.00 RV w RR(wzin) 4.06 0.00 0.00 0.00 0.00 CN adjusted 86 0 0 0 0 Summary Print