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HomeMy WebLinkAboutWPO202100022 Calculations 2021-08-20Southwood Redevelopment — Blocks 11&12 ALBEMARLE COUNTY, VIRGINIA WPO PLAN DESIGN CALCULATIONS & NARRATIVE APRIL 12, 2021 REv. AUGUST 20, 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 Bryan D. Cichocki Lie. No. 53741 g174/Z, y71/8 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 70 PROJECT: LOCATION: COUNTY: Designed by: Checked by: UNITS ENGLISH PIPE NO FROM POINT TO POINT DRAM. AREA "A" Acre (3) RUNOFF COEFF. "Cl (4) CA TOTAL INLET TIME Minutes (9) RAIN FALL IN (8) RUNOFF Q CFS (9) INVERT ELEVATIONS LENGTH nfPipe Ft (12) SLOPE F(N( (13) SIZE (Di3 Or SpaNRise) In. (14) SHAPE Capacity US (15) Friction Slope Ft/Ft. VEL V. FVSec (16) FLOW TIME Min. (19) REMARKS (18) MCR MENT (5) AOCUM- ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. 119 120 118 0. 140 0.350 0049 OM9 0000 60M 6230 0.305 488058 482260 80.774 0010 12.000 CireWar 3.858 DOFF 2939 0458 119C 118 1F16 0000 0000 Raao 0.355 0.306 6458 6098 2.165 486724 486480 48219 0005 15.000 Circular 4947 0001 3905 0208 Areafo.RDl 119A lim 116 0430 0.820 0353 0908 0.000 6666 6041 4274 486383 486310 14.%3 0005 15.000 Circular 4947 0004 4.548 0053 127 128 116 0.560 0740 0414 0414 0.000 60M 6230 2.582 486447 486310 25. 158 0005 15.000 Circular 5.159 0001 4214 0099 115 116 114 0000 0000 0000 1.122 0.000 6919 1 6026 6761 486211 485900 102.237 0005 1 18.000 Circular 8041 1 000,1 1 5.112 0333 113 114 112 0000 0000 1 0000 1392 0170 2053 5930 82" 485603 485430 34677 0005 21.000 Circular 12.136 0002 5439 0.1% Area from RD2 111 112 110 0000 0000 0000 1392 0.000 9.159 5909 8225 485330 4M 960 74039 0005 21.000 Circular 12.136 0002 5433 0229 109 110 108 0380 07N 0.139 1531 0000 9386 5850 8955 4M 855 4M 690 33080 0-005 21000 Ci.War 12136 0003 5532 0.100 125 126 108 0.150 0.350 0053 0053 0.000 60M 6230 0.327 4824W 486958 36790 0020 12.000 Ci®War 5457 DOFF 3.829 0.160 107 108 106 0000 0000 0000 1.583 0.000 7486 5825 9222 4M588 4M500 17519 0005 21.000 Cimular 14.136 0003 5.564 0052 123 124 106 0.160 0290 0.126 0. 126 0.000 60M 6230 0787 485644 485000 42933 0015 15.000 Circular 8568 DOFF 4.365 0.164 105 106 1W 0000 0000 0000 1210 0.000 7538 4M 326 4M 090 49.184 0005 2L000 Circular 12.136 0003 5M2 0.139 IN 1M 103 0210 0690 0.145 1.854 0.000 7678 4M 088 483080 201695 0005 21.000 Circular 12.136 0004 5709 0589 102 103 102 0000 0000 0000 1.854 0.000 $266 H5581111 482979 482570 81870 0005 21.000 Circular 12136 0004 5689 0240 121 122 102 0010 0.900 0009 0009 0.000 0000 486.830 486230 30014 0020 15.000 Circular 9.894 DOFF 2433 0206 101 102 EXMH 0030 0770 0023 1.887 0.000 $506 482472 482310 1 32417 1 aM5 1 21.000 Circular 12.136 0004 5695 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: 10 Year INLET OR JUNCTION INLET STATION OUTLET WATER SURFACE EIEV. OIA PIPE DO (In) DESIGN OISGH. Q. ICES) LENGTH PIPE LO (ED FRICTION SLOPE (FTIFT) FRICTION LOSS M (Ft) JUNCTION LOSS FINAL H (Ft) It W r Sutras E.H. M. Ekv COnmen6 Vo Ho (Fl) pi Vi pM V14118 HI Angle HA Ht 1.3 HI 05 H1 102 10+33.25 483.]1 21 10.53 32.42 0.38% 0.12 5.] 0.13 10.45 5.69 59.45 0.5 0.18 26.32 0.15 0.45 0 TRUE 0.35 484.06 493.17 OK -9.11 103 484.06 21 10.45 81.87 0.37% 0.3 5.69 0.13 10.]1 5.71 61.17 0.51 0.18 9.39 0.07 0.37 0 TRUE 0.49 484.55 493.04 OK -8.49 104 13+16.80 484.55 21 10.71 201.7 0.39% 0.79 5.]1 0.13 9.94 5.64 56.05 0.49 0.17 2.31 0 0.3 0 TRUE 0.94 485.48 490.93 OK -5.45 106 13a64.07 485.49 21 9.94 47.18 0.34% 0.16 5.64 0.12 9.22 5.56 51.31 0.48 0.17 86A4 0.34 0.63 0 TRUE 0.47 485.96 491.31 OK -5.35 108 13+81.]] 485.96 21 9.22 17.52 0.29% 0.05 5.56 0.12 8.95 5.53 49.53 0.48 0.17 90.36 0.33 0.62 0 TRUE 0.36 486.32 492.04 OK -5.]2 110 14+15.30 486.32 21 8.95 33.08 0.27% 0.09 5.53 0.12 8.23 5.43 44.69 0.46 0.16 91.33 0.32 0.6 0 TRUE 0.39 486.71 491.91 OK -5.2 112 14+89.33 486.71 21 8.23 74.04 0.23% 0.17 5.43 0.11 8.26 5.44 44.95 0.46 0.16 91.41 0.32 0.6 0 TRUE 0.47 487.18 492.76 OK -5.58 114 15+24.18 487.18 21 8.26 34.68 0.23% 0.08 5.44 0.11 6.]6 5.11 34.56 0.41 0.14 39.76 0.17 0.43 0 TRUE 0.3 487.48 492.9 OK -5.42 116 16+26.42 487.48 18 6.76 102.24 0.35% 0.36 5.11 0.1 4.27 4.55 19.44 0.32 0.11 96.91 0.19 0.41 0 TRUE 0.56 488.04 490.84 OK -2.8 117B 488.04 15 4.27 14.56 0.37% 0.05 4.55 0.08 2.16 3.91 8.46 0.24 0.08 4.02 0 0.16 0.21 TRUE 0.16 488.2 490.95 OK -2.75 118 16+89.63 488.2 15 2.16 48.72 0.10% 0.05 3.91 0.06 0.31 2.94 0.9 0.13 0.05 63.38 0.08 0.18 0 TRUE 0.14 488.34 491.89 OK -3.55 120 17+70.35 488.34 12 0.31 80.]] 0.01% 0.01 2.94 0.03 0 0 1 0 0 0 0 0 0.03 0.04 TRUE 0.03 488.37 492.21 OK -3.84 122 1 10+30.38 1 487.23 1 15 1 0.08 130.01 1 0.00% 1 0 1 2.43 1 0.02 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.02 1 0.03 1 TRUE 1 0.01 1487.24 1 493.09 1OK -5.84 124 1 10+43.92 1 486 1 15 1 0.79 142.93 1 0.01% 1 0.01 1 4.36 1 0.07 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.07 1 0.1 1 TRUE 1 0.05 1486.05 1 490.69 1OK 4.63 126 10+39.02 487.56 12 0.33 36.79 0.01% 0 3.83 0.06 0 0 0 0 0 0 0 0.06 0.07 1 TRUE 1 0.04 1 487.6 1 491.91 1OK 4.31 128 10+29.09 488.04 15 2.58 25.16 0.14% 0.03 4.21 0.07 0 0 0 0 0 0 0 0.07 0.09 1 TRUE 1 0.12 1488.171 489.83 1OK -1.66 �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