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HomeMy WebLinkAboutWPO202100022 Calculations 2022-05-04Southwood Redevelopment — Blocks 11&12 ALBEMARLE COUNTY, VIRGINIA WPO PLAN DESIGN CALCULATIONS & NARRATIVE APRIL 12, 2021 REV. AUGUST 20, 2021 REV. DECEMBER 17, 2021 REV. APRIL 5, 2022 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 hodd Z by the AlbemarleCounty Lie. No. 53741 Community Development Department V"jr/ZZ4 Date 5/4/22 File WP0202100022 0711A 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 ID 201 STORMWATER INLET COMPUTATIONS SHEET OF ROUTE PROJECT SOuNwxO_Block 11 DESIGNER: KAM OATS Y&ID21 CHECKED: UNIIS!NGUSH mmm�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�®®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomom®®m®®m®m®mmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmm®mmmmm�m�®®® m®m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmo®ommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmm®mmm®mmmmmmmmamm®mmmm�®mom INLE SOFT BY ENSOFTEC OATS My2021 FORM ID 201 STORMWATER INLET COMPUTATIONS SHEET OF ROUTE PROJECT SoLdwDW_BIp 12 DESIGNER: KAM OATS Y&ID21 CHECKED: UNIIS!NGUSH ®®m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�®®mmmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmomommmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmmmmmmmmmmmmmmmmmammmmmmm�®m® ®�m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomomm�mm®m®m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmmmmm®®m® ��m�mmm000ammmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmm�omomm�mmmm®m®mmmmmmmmmmm��mm mmm�mmmmmmmm®mmmmmmmmmmmammmm®mm®®®� ®�m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomomm�mmmm®m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmm®m®®®®® ��m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmm®o®om®�mmmmmm®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmammmmm®®mom®® ®�m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�m®�mmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmomommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmm�mmmmmmmmmmmmomm�mmmm��m® ®�m�mmmmmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�mmmmomom��mm��®m®mmmm®mmmmmm��m� ®�m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m mmm�®mmmmmmmmmmmmmmmmmmmmmmmmmmm��m� mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmm�o�omm�mm�m®m®mmmmmmmmmmm��m mmm�mmmmmmmm®mmmmmmmmmmmamm®mmmm®®®® m�m�mmm0000mmmmmmmmmmmmmmmmmmmmm��m� mmm�m®�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomommmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmm�mmmmmmmmmmmmommmmmmm�®mom m®m�mmm000ammmmmmmmmmmmmmmmmmmmm��m mmm�mm�mmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�m®mmmmmmmmmmmmmmmmmmmmmmmmmm��m mmm�mmmmomammmmmmmmmmmmmmmmmmmmm��m mmm�mmmmmmmmmmmmmmmmmmmm®mmmmmmm�mtm INLE SOFT BY ENSOFTEC OATS 6&2021 PHA Block 11 Storm STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 10 PROJECT: LOCATION: COUNTY: Designed by: Checked by: UNITS ENGLISN PIPE NO FROM PONT TO POMT DRAM. AREA "A" Acre (3) RUNOFF COEFF, "C" (4) CA TOTAL INLET TIME Minutes RAIN FALL oVw (8) RUNOFF Q CFS (9) R0TRTELEVATIONS LENGTH afPi, FL (12) SLOPE Ft AT (13) SIZE (Di. Or S,a ..) In (14) SHAPE Capacity CFS (15) Frictpn Slope Ftfft. VEL Vn FVSec (16) FLOW TIME Min (17) REMARKS (18) MCRE-ACCUM- MENT (5) ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. 203 204 202 0000 0000 0000 0.333 0333 6000 6230 2075 474.193 4]0342 80018 aN8 15.000 Chcnlar 15.328 0.001 8740 0.153 Area from MI 205 206 202 0440 0]00 Q308 0.308 0000 6000 6230 1919 4]0600 4703LM 42974 0006 12000 Cimular 2W3 0002 4.001 0.1N PHA BLOCK 12 STORM STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 10 PROJECT: LOCATION: COUNTY: Designed by: Checked by: UNITS ENGLISN PIPE NO FROM PONT TO POINT DRAM. AREA "A" Acre (3) RUNOFF COEFF, T' (4) CA TOTAL INLET TIME Minutes RAIN FALL 0Vw (8) RUNOFF Q CFS (9) INVERTELEVATIONS LENGTH afPipe IT (12) SLOPE Ft At. (13) SIZE (Di. Or SpaNRix) In (14) SHAPE Capacity CFS (15) Frictpn Slope Ft/Ft. VEL Vn FVSec (16) FLOW TIME Min (17) REMARKS (18) MCRE-ACCUM- MENT ULATED AODIL CA UPPER ENO (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. 119 120 HII 0.140 0.350 0049 ON9 0NO 6ON 6230 0.305 488058 487250 80774 0010 12.000 Cmular 3858 00W 2939 0458 117C 118 lim ONO ONO ONO 0.355 03M 6458 6099 2.165 486724 4864M 48719 0005 I5000 Ci.War 4947 0001 3905 0209 Area from RDI 117A lim 116 0430 0.820 0353 0708 0000 6666 6041 4274 486383 486310 14.%3 0005 15.NO Circular 4.W7 0004 4549 0053 129 128 116 0560 0.740 0414 0414 0000 6ON 6230 2.582 486447 496.310 25.158 0005 15.000 Circular 5.159 0001 4214 0OW 115 116 1 114 ONO OOW ONO 1.122 0NO 1 6719 6026 6761 486211 485700 102.237 1 0005 18.000 Ci¢War 8041 0WI 1 5.112 0.333 113 114 112 ONO ONO 0NO 1.392 02ID 7053 5937 82M 495 W3 4854M 346]] 0005 21 NO Cimulu 12.136 0002 5439 0.106 Area from RD2 111 112 110 (ION 0000 OMOO 1.392 0000 9.159 59M 8225 485.IN 484.960 74039 0005 21 NO Circular 12.136 0002 5433 0227 109 110 108 0.190 07V OA39 1.531 0000 7386 5850 8955 484.855 4M 6W 33080 0005 21.000 Circular 12.136 0W3 5.532 0.100 125 126 108 0.150 0.350 0053 0053 0000 6" 6230 0.327 487 4A 486758 36790 0020 12.000 Cmular 545/ (TOW 3.829 0.IN) 109 108 IN ONO ONO ONO 1.583 0000 74M 5825 9222 1 494599 484.500 17.519 0005 21 NO Cimulu 12.136 0003 5.5M 0052 123 124 IW 0.IN 07% 0.126 0126 0000 6ON 6230 0]8] 1 485644 4850W 42.933 0015 15.NO Circular 8.50 0000 4365 0.164 105 106 104 0000 0000 00W 1910 0000 7.538 5812 9936 484326 4M0% 47IM 0-005 21000 CiwWar 12136 0W3 5642 0139 1IN IN 103 0210 0690 0.145 1.SM 0000 7678 577 10.713 484099 483 ON 201695 0005 21.000 Cmular 12.136 0.004 5709 0589 102 103 102 0000 ONO ONO 1.854 0000 $266 5636 10451 4829]9 482.5]O 91.810 0005 21 NO C'mulu 12.136 0004 5689 0240 121 122 102 0010 0.900 0.009 0009 0000 OOW 8901 0080 486.8M 486230 30014 0020 15.NO Circular 9.SW 0000 2433 0206 101 102 EX MH 0030 OJ]0 0023 1.88] 0000 8.506 5581 10.528 4824]2 482310 3241] 0005 21 NO Circular 12.136 ROOd 5695 0095 PHA Black 11 Storm PROJECT: DESIGNED BY: HYDRAULIC GRADE LINE ANALYSIS Checked: 10 Year INLET INLET OUTLET WATER OIA. PIPE DESIGN DISCH. LENGTH PIPE FRICTION SLOPE, Wo FRICTION LOSS JUNCTION LOSS FINAL INeI W r 0. Co.Iz 1.3 05 OR STATION SURFACE Do Oo Lo IS Vo Ho Oi Vi OM VPYlg HI Angle HA HI HI HI H S.tl Ekv JUNCTION EIEV. (In) (CPS) (ED (FVFT) (Ft) (R) (FI) Elevliw 204 1 10+80.39 1 471.34 1 15 2.07 $0.02 0.09% 0.0] 8.74 0.3 0 0 0 0 0 0 0 0.3 0 TRUE 0.22 471.55 PHA BLOCK 12 STORM PROJECT: DESIGNED BY: HYDRAULIC GRADE LINE ANALYSIS Checked: 10 Year INLET OR JUNCTION INLET STATION OUTLET WATER SURFACE EIEV. M. PIPE Do (In) DESIGN DISCH. po (CPS) LENGTH PIPE LO (ED FRICTION SLOPE, Wo (FVFT) FRICTION LOSS M (FU(F[) JUNCTION LOSS FINAL H (ED INet W r Sutlx4 Eke li. RM Ekv Co.Is Ho Oi Vi DIM VI'Ylg HI Angk HA At 1.3 HI 05 HI 102 10+33.25 483.71 21 10.53 32.42 0.38% 0.12 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 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 j5.43 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 -5.45 105 13a64.07 485.49 21 9.94 47.18 0.34% 0.16 0.12 9.22 5.56 51.31 0.48 0.17 86.M 0.34 0.0 0 TRUE 0.47 485.96 491.31 OK -5.35 108 13+81]1 485.96 21 9.22 17.52 0.29% 0.05 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 -5.72 110 14+15.30 486.32 21 8.95 33.08 0.27% 0.09 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 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+24.18 481.18 21 8.26 34.68 0.23% 0.08 5.44 0.1 66.]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 48].48 18 6.]6 102.24 0.35% 0.36 5.H 0.1 4.2] 4.55 19.44 0.32 O.N 96.91 0.19 0.41 0 TRUE 0.56 488.04 490.84 OK -2.8 1178 488.04 15 4.27 14.56 0.3]% 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 1]+]0.35 488.34 1 12 1 0.31 1 80.771 0.01% 1 0.01 2.99 0.03 0 0 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 0.00% 0 2.43 ).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 1 OK -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 �.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 TRUE 0.04 487.6 491.91 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 TRUE 0.12 488.17 489.83 1OK -1.66 Drainage Area A Drainage Ama A land Cover (acres Soils Soils Soih and, Wls Wls [aatl faerM ' naVOpm$oalazevl D.L-0 nN WnagENFla[ml 0.16 n16 n}ll IigeMwx[w'n laartvl 0.18 Offi D95 Total Phosphorus Available for Removal In D.A. Ailiven) D.RB Total D.N Port Development TreMmeM Volume In D.A. A)1Ix) Stormwater Best Management Pracices (RR a Runoff Reducion) _Solent from dmpdmn Ilon- aboard Mandel Impervious Voume team Runoff Remalnft Taal BMP PMspw hui Plamphoms Wad UM[eabPlantain—Plantain— Remand" Plaudit. Retlu[tlon Tull CfedN Loved CreER UpiVeam x Runon Volume Trertment Remand fom Upstream PhmpM[us lead Reanvatl By Phoe,hom[tom! pow�nbea unMaple mbe Credo)%) Area(abet) Area lanes) P.,be nta) Redu[Xon (R) (na) Volume(W) Lfn[Ien[y)%) fatten (a) mPn[tam jib) Pran Wit) ilb) Em Area z, a Pmitlt)SPe[M) I E. Veguel Pml@UPee6) M 0 0 Y 0 OW 6W O.OI a, alertlbaa.aal _ _ en. Ayaneua: aim Ro a o o a .o om am Den Den Nm,,n Removal mu en[y)%) NMogen batl hom Ummeam Practices)Ibs) WNeMed Attention load to Moabite (Ned NNr"en Remeaed By Practice (d s) Re ." Abandon laatl )Ib) mad Is A - TMALIMPERVIOUSCOVERTREATE.)ae) D.2B AREACHECR: OR. TOTALMAMAGEDNRFAREATRG,EO )a[) D.16 AREACH. OR. T.MANOFFRE.UCFIONINDAA(UP) RSS TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IND.A. A)14/yc) Of4 TOTAL PHOSPHORUS REMOVED PH RUNOFF REDUCTION PMCFNESIN DA AIIb/yc) D.61 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACDCES IN D.A. A)Ib/y1) RDT SEE WATER QUALITY COMYLWNCF TAB FOR SITE COMPLIANCE CALCULATIONS TOTAL IMPERVIOUS COVER TREATED).¢) D.2B AREACHECR: OR. TOTALMANAGEDNRFAREATREAMID(ae) Dm AREACHE(lK: OR. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SIMHb/yc) 1.50 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A.ARb/yn) D.69 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. A)Ib/yr) O.OS TOTAL PHOSPHORUS REMOVED WRH RUNOFF REDUCTION PRACFKES IN D.A. A)Ib/atI 0.61 TOTAL PH.lPNORUS LOADREDUCFION ACHIEVED I N DA A Rb/yr) Ufb TOTAL PHOSPHORUS REMAINI NO AFTER APPLYI NO BAP MAD REDUCTIONS IN D.A. A)M/yr) 0.02 9. SbeAflow to FiNer/Open Space HHU TOTAL RUNOFF REDUCHON IN D.A. A(WI 8G5 NITROGEN REMOVE. Aft. RUNOFF REDUCTION PRRCTC6 IN D.A. A)Ib/yr) I 'A, SEE WATER QUALIFY COMPLDINCE TAB FOR SRE CALCULA TIONS (Infoemafion Only) cl A. SEE WATER QUALI N COMPLIANCE TAR FOR SITE COMPLIANCE CALCULATIONS NDROGENREMOVEDW HMNOEf REDURIONPMRKESIND.P.P11b/y�� 0.0] MOROGEN REMOVED WITHOUT RUNOfi REDUC]ION PMEIICES IH D.A. RIIb/yA O.0) TOTRL NITROG E N REMOVED IN D.R. R(A/y,) 6.0] Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Draft 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 BSoils CSolls 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 CSoils DSoils Totals %of Total forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Tarf(acrez) 1 0.00 0.43 0.00 0.00 0.43 34 Impervious Cover (acres) 0.00 0.84 0.00 0.00 0.84 66 1.27 100 Site Tv and Land Cover Nutrient Loads Final Post -Development post- Post Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment rvious &New lm pe ) (New Impervious) Site Rv 0.70 0.20 0.95 0.20 Treatment Volume (W) 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' "aeeurnon below new devempment load limitation notoquired 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 (lb/yr) 14.42 4.14 Pre- ReDevelopment Final Pont -Development TP Load per acre TP Load per acre :SI (lb/acre/yr) (Ih/acre/yr) 0.46 1.59 Summary Print Virginia Runoff Reduction Method Worksheet Site Compliance Summary Maximum% Reduction Required Below m% 'Note:% Reduction will reduce post- development TP load to less than or equal to baseline load of0.38 lb/yr(0.41 lb/ac/yr) Pre-ReDevelopment Load (Required reducdonfor Post-RCDeV=Post-REDav TP load- baseline two of0.17S 1b/yr), baseline land=site area x 0.4116/ac/yr Total Runoff Volume Reduction (ft) 865 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 (lb/yr) 0.94 Required *Reduction below new development load limitation not required Summary Print Virginia Runoff Reduction Method Worioneet Drainage Area Summary D.A. A D.A. B D.A. C D.A. D DA. E Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acres) 0.16 0.00 0.00 0.00 0.00 0.16 Impervious Cover (acres) 0.28 0.00 0.00 0.00 0.00 0.28 Total Area (acres) 0." 0.00 0.00 0.00 0.00 0." 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 Redun6on Method Worioneet ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Runoff Volume and CN Calculations 1-yearstorm 2-yearstorm 10-yearstorm target Rainfall Event (in( 1 3.04 3.68 5.57 Drainage Areas RV & CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN 85 0 0 0 0 RR (ft?) 865 0 0 0 0 1-year return period RV wa For (.sir) 1.62 0.00 0.00 0.00 OAO RV w RR fue,m) 1.08 0.00 OAO 0.00 OAO CN adjusted 77 0 0 0 0 2-year return period RV wa RR(ws-in) 2.17 0.00 OAO 0.00 OAO RV w RR(wsin) 1.63 0.00 OAO 0.00 OAO CN adjusted 78 0 0 0 0 10-year return period RV wa RR(Zin) 3.90 0.00 OAO 0.00 OAO RV w RR(w"n) 3.36 0.00 0.00 0.00 OAO CN adjusted 80 0 0 0 0 Summary Print Drainage Area A Uralnage Wea A lantl Cheer (acres Soils Soils Soih Soils Is [aatl faerM ' naVOpm$oalazevl O.L-0 ON WnagENFla[ml 058 0.58 0211 IigeMwx[w'n laartvl 16R SE8 n95 Total Pro,morns Anllable for Remoon In D.A. Ailb/yri 3.ga Tratall 2.26 Port Detelopment Treatment Volume In DA A(W) 6.215 Stormarater Best Management Pracices (RR a Runoff Reducion) _imett from ampaawn Ilsn- Runoff standard Impervloux Vdume fmm Runs% Rn mmus, Taal.MP Phosphorus Phosphorus Wad UnXeab! PMsphow RemaAlq P!d[[I[[ RetluNon Tull CfedN LOVeI CreEX UpiVeam Runrn Volume Treatment pennval from Upstream Phosphorus Wild Improved By Pho lmspmat-c! Daw�nneahooranl[em be C.. (%) Area pums) Area panes) P[a[tl[e (tla) ReEu[Xon (Rx) iXal Volume)Xv) Officina y)%) retakes (lb) mPn[iRe jib) PramWie) ilb) ongopera z, ,haa pare SPe[M) I E. Veguel Pml@UPee61 W 0 0 Y 0 0W OW II.OI a, alertlbaa.aal - -Or Rn.bnueua:e mp m a b b a .p bm Om pm Rm latera n Removal miken[V(%) NMogen batl from UpWVam Pra[ti[es)Irs) U.d Nlbgen Wass to Pn[Ge)Ws) N"en Rennuetl Py Practice lips) Re ." hats nlnatl )Ib) an rad end a. 20 On Race"11H TOTALIMPERVIOUSCOVERTRCATE.)ae) 0.39 AREACHECR: OK. TOTALMAMAGEDNRFAREATRG,EO )a[) D.11 AREACH. OK. iOTAIRUHOFFRE.UCFIONINDAA(R?) E�159 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. ARb/y`) 390 TOTAL PHOSPHORUS REMOVED MOH RUNOFF REDUCTION PMCFNESIN DA A)Ib/y�) 1.38 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACDCES IN D.A. A pb/y1) J.SJ SEE WATER QUALITyCOMYLWNCE TAB FORSIM COMPLIANCE CALCULAITIONS TMAL IMPERVIOUS COVERTRCATE.)ae) I.GJ AREACHECK: OR. TOTALMANAGEDNRFAREATRCATED)ae) 011 AREA CHECK: OR. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE Hb/yc) 3C8 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A.ARb/yr) 3.90 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. A)Ib/y� 1.32 TOTAL PHOSPHORUS REMOVED WRH RUNOFF REDUCTION PRACTCES IN D.A. A)Ib/ytI 1.38 TCHALPHOSPNORUS LOADREDUCTION ACHIEVED IN DA A)Ib/yr) J.]O COTAL PHOSPHORUS REMAINING AFTER APPLYING BMP MAD REDUCTIONS IN D.A. A)M/yr) L31 9. Sbeelflow to FiNer/Open Space HHU TOTAL RUNOFF REDUCHON IN D.A. A(wi J.159 NITROGEN REMOVE. WDN RUNOFF REDUCTION PRRCIC6IN D.A AIIWr)11.15 SEE WATER OUALIFT COMPLIANCE TAB FOR ST E CALCULATIONS (Infoemafion Only) an 13. Wet Ponds no RR) 11, ManuInstance! IMP RR) (no SEE WATER QUALI N COMPLIANCE TAR FOR SITE COMPLIANCE CALCULATIONS NDROGENREMOVEDW HMNOEf REDURIONPMRKESIND.P.P116/y�� 11.15 MOROGEN REMOVED WITHOUT RUNOfi REDUCTION PMEIICES IH D.A. RIIb/yA O.O] TOTRL NITROG E N REMOVED IN D.A.A(A/y) ILIS Site uite(Water quality Compliance) Area [Rx45 idssi/ndma¢yy tbrteyO rtolxl upy rtolal SM1Treadmm VWumelRil rXe Runa Reductioa VMume and TP RY aaiwBe A a tvmlx'I EJsf wm Oe/nl nn lie/nl ma—,.. TOM Phnip�oms re.onanl am Dora .mxnnaoe mpwa: TO lNft gen (fw Inldmalioa pury ) maOlNvrl erm I�wnl mm OaMl Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Draft 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) A soils BSolis CSolls 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) A soils 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 0.88 a00 0.00 0.88 31 Impervious Cover (acres) 0.00 1.96 0.00 0.00 1.96 69 2.94 100 Site Tv and Land Cover Nutrient Loads Final Post -Development post- Post Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment m rvious &New l pe ) (New Impervious) Site Rv 0.72 0.20 0.95 0.20 Treatment Volume (W) 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' "aeeurnon below new devempment load limitation notoquired Total TP Load Reduction Required (lb/yr) 3.48 0.04 3.44 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (lb/yr) 33.25 9.27 Pre- ReDevelopment Final Pont -Development TP Load per acre TP Load per acre :SI (lb/acre/yr) (Ih/acre/yr) 0.46 1.64 Summary Print Virginia Runoff Reduction Method Worksheet Site Compliance Summary Maximum% Reduction Required Below 20% 'Note:% Reduction will reduce post- development TP load to less than or equal to baseline load of0.36 lb/yr(0.41 lb/ac/yr) Pre-ReDevelopment Load (Required reducdonfor Post-RCDeV=Post-REDav TP load- baseline two of0.360R Ib/yr), baseline land=site area x 0.4116/ac/yr Total Runoff Volume Reduction (ft) 2,359 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 (lb/yr) 0.79 Required *Reduction below new development load limitation not required Summary Print Virginia Runoff Reduction Method Worioneet Drainage Area Summary D.A. A D.A. B D.A. C D.A. D DA. E Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acres) 0.58 0.00 0.00 0.00 0.00 0.58 Impervious Cover (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 Redurbon Method Worioneet ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Runoff Volume and CN Calculations 1-year storm 2-yearstorm 10-yearstorm target Rainfall Event (in) 1 3.04 3.68 5.57 Drainage Areas RV & CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN 89 0 0 0 0 RR(ft?) 2,159 0 0 0 0 1-year return period RV wa For (.sir) 1.94 0.00 0.00 0.00 OAO RV w RR fue,m) 1.67 0.00 OAO 0.00 OAO CN adjusted 86 0 0 0 0 2-year return period RV wa RR(ws-in) 2.52 0.00 OAO 0.00 OAO RV w RR(wsin) 2.26 0.00 OAO 0.00 OAO CN adjusted 86 0 0 0 0 10-year return period RV wa aR(Zin) 4.32 0.00 OAO 0.00 OAO RV w RR(vem) 4.06 0.00 0.00 0.00 OAO CN adjusted 86 0 0 0 0 Summary Print