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HomeMy WebLinkAboutWPO201800078 Calculations 2020-01-06Keswick Hall Spa WPO 201800078 COUNTY OF ALBEMARLE, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE OCTOBER 22, 2018 REVISED: FEBRUARY 15, 2019 JANUARY 6, 2020 .``ft* 0 � 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 'J CRAIGW Y. KO'r'AR.sm Lic. No. 040204850' kO I -06 -.2 �`v��NAL �s Table of Contents Section Title Project Narrative 2 Pipe and Inlet Computations 3 Virginia Runoff Reduction Method Worksheet Summary 4 Pre -Developed HydroCAD Calculations 5 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 1b/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 0.36 lb/yr. Water Quantity CoMpliance: Stormwater Quantity requirements for analysis point I 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 LD 204 STORMWATER INLET COMPUTATIONS SHEET 1 OF 1 ROUTE Club Drive PROJECT Keswick Hall Spa DESIGNER: CG DATE 11612020 CHECKED: CK UNITS INGLISH ®� .III 11 I ® I I -------------------------__-® --- 1111 ' -- 1 1 � 1 1 • �- I I 11 I I 11 ® III ® I I 11 �- 11 -----------__-® �� .III 1 .I ®®-------------------------__-® �� .III 1 I ®®-------------------------__-® �� III 1 I.I ® I 1 .. -------------------------__-® INLETSOFT BY ENSOFTEC DATE: 1/6/2020 LD-229 PROJECT: Keswick Hall Spa STORM SEWER DESIGN COMPUTATIONS LOCATION: Charlottesville COUNTY: Charlottesville STORM FREQUENCY 10 Designed by: CG Checked by: CK UNITS ENGLISH PIPE NO. FROM POINT TO POINT DRAIN. AREA "A" Acre 3 RUNOFF COEFF. "C" 4 CA INLET TIME Minutes 7 RAIN FALL In/lit 8 RUNOFF INVERT ELEVATIONS LENGTH of Pipe Ft. 12 SLOPE Ft./Ft. 13 SIZE (Dia. Or Span/Rise) In. 14 SHAPE Number of Pipes Capacity CFS IS Friction Slope Ft./Ft. NORMAL FLOW FLOW TIME INCRE- ACCUMU MENT -IATED REMARKS Minutes Minutes 17 17 18 INCRE- MENT 5 ACCUM- ULATED 6 Lateral CFS Tota1Q CFS 9 UPPER END 10 LOWER END 11 Depth of Flow, do Ft. Area of Flow, An SgFt H. Ft. Vn Ft/Sec 16 En Ft. REFERENCE 1 STA. REFERENCE 2 STA. 101 102 100 0.00 0.00 0.00 5.90 6.26 0.00 6.45 412.23 411.29 82.53 0.01139 24 Circular 1 26.16 0,00070 0.68 0.94 0.38 6.89 1.42 0.20 6.10 103 104 102 0.00 0.00 0.00 5.27 6.45 0.00 6.45 413.50 412.33 116.56 0.01004 24 Circular 1 8.93 0.00550 1.26 2.08 0.57 3.10 1.41 0.63 5.90 105 106 1104 1 0.00 1 0.00 0.00 1 5.18 6.48 1 0.00 6.45 413.97 413.60 36.95 10.01001 18 1 Circular 1 11.39 0,003301 0.81 0.97 0.39 6.64 1.49 0.09 5.27 107 108 106 0.00 0.00 0.00 5.09 6.51 0.00 6.45 1 415.80 414.07 57.73 0.02997 18 Circular 1 19.70 0.00330 0.59 0.65 0.32 1 9.98 1 2.14 0.10 5.18 109 SWM3 OUT 108 0.00 0.00 0.00 5.00 0.00 0.00 6.45 422.00 419.75 56.22 0.04002 18 Circular 1 22.77 0,00330 0.55 0.58 0.30 11.09 2.46 0.09 5.09 111 112 SWM3 IN 0.00 0.00 0.10 5.14 6.50 0.00 0.65 425.02 424.78 23.97 0.01001 12 Circular 1 3.86 0.00030 0.28 0.18 0.16 3.66 0.49 0.11 5.25 113 114 112 0.14 0.71 0.10 0.10 5.00 6.54 0.00 0.65 425.41 425.12 29.79 0.00973 12 Circular 1 3.81 0,00030 0.28 0.18 0.16 3.63 0.49 0.14 5.14 115 116 SWM3 IN 0.28 0.70 0.20 0.20 5.00 6.54 0.00 1.29 425.51 424.24 27.00 0.04704 12 Circular 1 837 0.00120 0.27 0.17 0.15 7.73 1.19 0.06 5.06 117 118 SWM3 IN 0.26 0.52 0.14 0.60 5.61 6.35 0.00 3.82 423.02 422.13 88.94 0.01001 15 Circular 1 7.00 0,00310 0.66 0.66 0.32 5.83 1.19 0.25 5.87 119 120 118 0.51 1 0.39 0.20 0.42 1 5.50 6.38 0.00 2.66 423.49 1 423.12 37.05 0.009991 15 Circular, 1 7.00 0.00150 0.53 0.50 0.28 5.31 0.97 0.12 5.61 121 122 120 0.26 0.47 0.I 0.16 5.28 6.45 0.00 1.06 425.98 423.59 79.53 0.03005 12 Circular 1 6.69 0,00080 0.27 0.17 1 0.16 6.22 0.87 0.21 5.50 123 124 122 0.08 0.51 0.04 0.04 5.00 6.54 0.00 0.27 428.19 426.08 70.30 0.03001 12 Circular 1 6.69 0.00010 0.14 0.06 1 0.09 4.16 0.41 0.28 5.28 125 126 120 0.09 0.60 0.05 0.05 5.00 6.54 0.00 0.35 423.63 423.59 3.98 0.01005 8 Circular 1 1.31 0,00080 0.24 0.11 0.13 3.19 0.39 0.02 5.02 127 128 118 0.06 0.32 0.02 0.02 5.00 6.54 0.00 0.12 424.02 423.71 31.21 0.00993 12 Circular 1 3.85 0.00000 0.12 0.06 0.08 2.25 0.20 0.23 5.23 129 130 118 0.06 0.48 0.03 0.03 5.00 6.54 0.00 0.19 425.00 424.90 4.03 0,02481 8 Circular 1 2.06 0,00020 0.14 0.05 0.08 3.70 0.35 0.02 5.02 LD-347 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: CK INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION STA. INVERT EL. OUTFLOW PIPE DEPTH OF FLOW OUTFLOW PIPE OUTLET WATER SURFACE ELEV. DIA. PIPE Do In/mm DESIGN DISCH. Q. CFS/CMS LENGTH PIPE Lo FUM) FRICTION SLOPE, Sfo (FT/FT) (M/M) FRICTION LOSS Hf (Ft/M JUNCTION LOSS SURFACE FLOW Adj. Ht 1.3 Ht Ff/M Inlet Shaping? Y/N 0.5 Ht Ft/M FINAL H Ft/M Inlet Water Surface Elevation Top of MH Top of Inlet Ele, APPROX. Adjustment? Vo Comr. Ho Ft/M Vi Vi"2/2g Hi (Expn) 0.35"MAX. V2/2 SKEW Angle K Bend H Ff/M Sum HL Ft/M 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 17 18 19 100 412.000 102 411.290 2.00 412.890 24 6.450 82.53 0.00072 0.060 6.894 0.185 3.096 0.149 0.052 0.0 0.00 0.000 0.237 0.000 0.237 YES 0.118 0.178 413.068 420.930 O.K. 104 412.330 2.00 413.930 24 6.450 116.56 0.00548 0.638 3.096 0.037 6.643 0.685 1 0.240 0.0 1 0.00 0.000 0.277 0.000 0.277 YES 0.139 0.777 414.759 418.490 O.K. 106 413.600 1.50 414.800 18 6.450 36.95 0.00336 0.124 6.643 0.171 9.980 1.547 0.541 0.0 0.00 0.000 0.713 0.000 0.713 YES 0.356 0.480 415.280 418.180 O.K. 108 414.070 1.50 415.280 18 6.450 57.73 0.00336 0.194 9.980 0.387 11.086 1.908 0.668 0.0 0.00 0.000 1.055 0.000 1.055 YES 0.527 0.721 416.391 425.960 O.K. WM3 OU- 419.750 1.50 420.950 18 6.450 56.22 0,10336 0.189 11,086 0,477 0,000 0.000 0.000 0.0 0.00 0.000 0.477 0.000 0.477 YES 0.239 0.427 422.546 427.000 O.K. LD-347 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: CK INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION STA. INVERT EL. OUTFLOW PIPE DEPTH OF FLOW OUTFLOW PIPE OUTLET WATER SURFACE ELEV. DIA. PIPE Do (In/mm) DESIGN DISCH. Do (CFS/CMS) LENGTH PIPE Lo (FtlM) FRICTION SLOPE, Sfo (FT/FT) (M/M) FRICTION LOSS Hf (FtlM) JUNCTION LOSS SURFACE FLOW Adj. Ht 1.3 Ht (FUM) Inlet Shaping? Y/N 0.5 Ht (FUM) FINAL H (FtlM) Inlet Water Surface Elevation Top of MH Top of Inlet Elev. APPROX. Adjustment? Vo Contr. Ho (FtlM) Vi Vi'2/2g Hi (E)pn) 0.35`MAX. (V12/2g) SKEW Angle K Bend H (FtlM) Sum HL (Ft/M) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 17 18 19 SWM3 IN 424.000 118 422.130 1.25 424.000 15 3.817 88.94 0.00311 0.277 5.829 0.132 5.309 0.438 0.153 0.0 0.00 0.000 0.285 0.857 0.371 YES 0.185 0.462 424.462 428.570 O.K. 120 423.120 1.25 424.462 15 2.655 37.05 0.00150 0.056 5.309 0.109 6.218 0.600 0.210 0.0 0.00 0.000 0.320 1.270 0.415 YES 0.208 0.263 424.725 428.570 O.K. 122 423.590 1.00 424.725 12 1.055 79.53 0.00078 0.062 6.218 0.150 4.160 0.269 0.094 0.0 0.00 0.000 0.244 0.787 0.317 YES 0.159 0.221 426.248 430.260 O.K. 124 426.080 1.00 426.880 12 0.268 70.30 0.00005 0.004 4.160 0.067 0.000 0.000 0.000 0.0 0.00 0.000 0.067 0.268 0.087 YES 0.044 0.047 428.327 432.720 O.K. 116 424.240 1.00 425.040 12 1.289 27.00 0.00117 0.031 7.726 0.232 0.000 0.000 0.000 0.0 0.00 0.000 0.232 1.289 0.301 YES 0.151 0.182 425.775 429.910 O.K. 112 424.780 1.00 425.580 12 0.654 23.97 0.00030 0.007 3.664 0.052 3.628 0.204 0.072 0.0 0.00 0.000 0.124 0.000 0.124 YES 0.062 0.069 425.649 430.190 O.K. 114 425.120 1.00 425.920 12 0.654 29.79 0.00030 0.009 3.628 0.051 0.000 0.000 0.000 0.0 0.00 0.000 0.051 0.654 0.066 YES 0.033 0.042 425.962 429.790 O.K. 128 423.710 1.00 424.510 12 0.124 31.21 0.00001 0.000 2.251 0.020 0.000 0.000 0.000 0.0 0.00 0.000 0.020 0.124 0.026 YES 0.013 0.013 424.523 427.820 O.K. 130 424.900 0.67 425.433 8 0.190 4.03 0.00022 0.001 3.701 0.053 0.000 0.000 0.000 0.0 0.00 0.000 0.053 0.190 0.069 YES 1 0.035 1 0.035 1425.4691 427.190 1 O.K. 126 423.590 0.67 424.725 8 0.353 3.98 0.00076 0.003 3.194 0.040 0.000 0.000 0.000 0.0 0.00 0.000 0.040 0.353 0.051 YES 1 0.026 0.029 424.754 427.070 1 O.K. 0 Drainage Area A Mainaae Area A Land Cover 1.-0 A Soils B Soils C Soils D Soils Totals Land Cover Rv Forest/Opsn Space( acres) 0.00 0.00 Managed Turf(acres) 0.39 0.39 0.25 Impervious Cover (acres) 0.70 0.70 0.95 Total 1.09 Stormwater Rest Management Practices (RR = Runoff Reduction) Total Phosphorus Available for Removal in D.A. A (Ib/yr) 1.74 Post Development Treatment Volume in D.A. A (k)2.768 Runoff Managed Impervious Volume from Runoff Remaining Total BMP Phosphorus Phosphorus Load Untreated Phosphorus Remaining Downstream Practice to be Practice Reduction Turf Credit Cover Credit Upstream Reduction (k') Runoff Volume Treatment Removal from Upstream Phosphorus Load Removed By Phosphorus Load Employed Credit (%) Area (acres) Area (acres) Practice (k') (k') Volume (k') Efficiency (%) Practices (lb) to Practice (lb) Practice (lb) fib) S.a. Vegetated Roof #1(Spec #5) 45 0 0 0 0 0.00 0.00 0.00 1. b. Vegetated Roof #2 (Spec #5) g0 0 0 0 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 2.b. Simple Disconnection to C/D Soil, 2.d. To Dry WO or French Drain #1, 3. Permeable Pavement (RR) 4. Grass Channel (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 7. Infiltration (RR) 8. Extended Detention Pond (RR) Nitrogen Nitrogen Load Untreated Nitrogen Remaining Removal from Upstream Nitrogen Load to Removed By Nitrogen Load Efficiency (%) Practices(lbs) Practice (Ibs) Practice(Ibs) (Ibs) 0 0.00 0.00 0.00 0 o.w 0.00 0.00 2. Rooftop Disconnection (RR) Lavement (RR) 4. Grass Channel (RR) S. Dry Swale (RR) �60�0.00 - 7. Infiltration (RR) 8. Extended Detention Pond (RR) 20.01.02 HeswiG_Hall (Spa}VRRM_RaOav_Dmnplian- Spreatlahaet_v3_052016 DA. A B.b. FD.1 IS—.111 15 0 0 0 0 15 0.no 0.00 0.no ono 10 0.no 0.no ..no 0.00 9. Sheetflow to Filter/Open Space (RR) TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac)l 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. A [W)j 716 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRARICES IN D.A. A (II, 0.55 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 1.19 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS t Swale (no RR) 11. Filtering Practices (no RR) 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 14. Manufactured Treatment Devices (no RR) TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED(ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (lb/yr) 1.26 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRARICES IN D.A. A (Ib/yr) 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 0.55 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. A (Ib/yr) 0.66 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. A (lb/yi 1.19 9. Sheetflow to TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac)l 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. A [W)j 716 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRARICES IN D.A. A (II, 0.55 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 1.19 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS t Swale (no RR) 11. Filtering Practices (no RR) 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 14. Manufactured Treatment Devices (no RR) TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED(ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (lb/yr) 1.26 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRARICES IN D.A. A (Ib/yr) 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 0.55 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. A (Ib/yr) 0.66 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. A (lb/yi 1.19 9. Sheetflow to 14. Manufactured Treatment Devices (no RR) TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED(ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (lb/yr) 1.26 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRARICES IN D.A. A (Ib/yr) 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 0.55 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. A (Ib/yr) 0.66 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. A (lb/yi 1.19 9. Sheetflow to TOTAL IMPERVIOUS COVER TREATED (ac) 0.31 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED(ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (lb/yr) 1.26 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. A (Ib/yr) 1.74 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRARICES IN D.A. A (Ib/yr) 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 0.55 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. A (Ib/yr) 0.66 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. A (lb/yi 1.19 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. A iti 716 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr) 1 4.09 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale (Coastal Plain) (no RR) u o.00 oao o.00 o.no - 0.00 0.00 0.00 0.00 Practices (no RR) 0 r1l.Filtering ructed Wetland (no RR) ®®®® 0 13. Wet Ponds (no RR) 14. Manufactured BMP (no RR) 14. Manufactured BMP (no RR) 20.01.02 HeswiG_Hall (Sp.}VRRM_ReOav_Dmnpli-preetlaHae� v3_052016 DA. A SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yrl 4.09 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. A (lb/yr( 0.00 TOTAL NITROGEN REMOVED IN D.A. A(lb/yr) 4.09 Drainage Area B nrainaee Area A i and rnver t.,r i A Soils B Soils C Soils D Soils Totals land Cover Rv Forest/Open Spam (acres) 0.00 0.00 Managed Turf (acres) 0.55 0.55 0.25 Impervious Cover (acres) 0.38 0.38 0.95 Total 0.93 Storrnwatpr Rest Manaepmpnt Practices (RR = Runoff Reduction) 20.01.02 Keswick He (Spa)-VRRM_ReDev_Campliance_Spreadsheet _0 052016 D.A. B Total Phosphorus Available for Removal in D.A. B (lb/yr) 1.14 Post Development Treatment Volume in D.A. B (ft3)1 1,810 __Gnln�r i.nm d.nndnwn lieie_ Phosphorus Untreated Runoff Managed Impervious Volumefrom Runoff Remaining Total Phosphorus Load from Phosphorus Phosphorus Remaining Downstream Practice to be Practice Reduction Turf Credit Cover Credit Upstream Reduction Ift') Runoff Treatment Removal Upstream Load to Removed By Phosphorus Employed Credit (%) Area (acres) Area (acres) Practice (fN) Volume (ft') Volume (ft') Efficiency (%) Practices (lb) Practice (lb) Practice (lb) Load (lb) 1.a. Vegetated Roof ##(Spec ft5) 45 0 0 0 0 0.00 0.00 0.00 1.b. Vegetated Roof ft2 (Spec ft5) 60 0 0 0 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 2.a. Simple Disconnection to A/B Soils 2.b. Simple Disconnection to C/D Soils 2.c. To Soil Amended FiLr Path as per 2.d. To Dry Well or French Drain #1, 2.e. To Dry Well or French Drain #2, Micro -infiltration #2 (Spec #8) i�0000® 2g. To Rain Garden #2, ��0000� 2.h. To Rainwater Harvesting (Spec #6� 0 i�00000 13. Permeable Pavement (RR) Is. Permeable Pavement #1 (Spec #71 It. Permeable Pavement #2 (Spec #71 4. Grass Channel (RR) 4.a. Grass Channel A/B Soils (Spec 43) 4.1b. Grass Channel C/D Soil, (Spec #3� 5. Dry Swale (RR) �6. Bioretention (RR) Nitrogen Nitrogen Load Untreated Nitrogen Remaining Removal from Upstream Nitrogen Load to Removed By Nitrogen Efficiency (%) Practices (Ibs) Practice (Ibs) Practice (Ibs) Load (Ibs) 0 0.00 0.00 0.00 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 0 3. Permeable Pavement (RR) 4. Grass Channel (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 1/6Iz020 5 of 25 8:43 AM 20.01.02 Keswick_Hall (Spa}VRRM_ReD- C—pliance_Spreadaheet_v3_052016 D.A. B 7. Infiltration (RR) 8. Extended Detention Pond (RR) 19. Sheetflow to Filter/Open Space (RR) 9.b. Sheetflow to Conservation Area, C/o Solis TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL TURF AREA TREATED(ac) 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. B (fP) 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. B (Ib/yr 1.14 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 1.14 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS 110. Wet Swale (no RR) 1. Filtering Practices (no RR) 13. Wet Ponds (no RR) 60 0.00 0.00 0.00 0.00 7. Infiltration (RR) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. B (fP) 0 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. B (lb/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale Plain) RR) (Coastal (no 11. Filtering Practices RR) (no 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 1/6/2020 6 of 25 8:43 AM 20,01,02 K.—k_Hall (Spa)-VRRM_ReDev_Compliance__Sp—dsh-t_v3_052016 D.A. B 14. Manufactured Treatment Devices RR) (no TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (Ib/yr) 1.28 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. B (Ib/yr 1.14 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 0.00 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. B (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. B (Ib/yr 1.14 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 0.00 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. B (Ib/yr 0.00 TOTAL NITROGEN REMOVED IN D.A. B (Ib/yr) 0.00 14. Manufactured BMP RR) (no 1/6/2020 of 25 8:43 AM Drainage Area C nrainaee Area A i and rnver t.,r l A Soils B Soils C Soils D Soils Totals land Cover Rv Forest/Open Spam (acres) 0.00 0.00 Managed Turf (acres) 0.00 0.00 Impervious Cover (acres) 0.00 0.00 Total 0.00 Stormwatpr Rest Manaepmpnt Practices (RR = Runoff Reduction) 20.01.02 Keswick He (Spa)-VRRM_ReDev_Campliance_Spreadsheet _0 052016 CA. C Tota l Phosphorus Available for Remova l in D.A. Clb/yr) 0.00 Post Development Treatment Volume in D.A. C (fta) 0 ( __Gnln�r i.nm d.nndnwn lieie_ Runoff Managed Impervious Volumefrom Runoff Remaining 7otaIBMP rus Untreated Phosphorus Remaining Practice Reduction Turf Credit Cover Credit Upstream Reduction Runoff Treatmentom Phosphorus Removed By Phosphorus Downstream Practice to be Credit (%) Area (acres) Area (acres) practice (fta) (ft3) Volume (fit) Volume (ft3) am Load to practice (lb) Load (lb) Employed [lb) Practice (Ib) 4-ii4i 1.a. Vegetated Roof #1(Spec #5) 45 0 0 0 0.00 0.00 0.00 Lb. Vegetated Roof #2 (Spec #5) a) 0 0 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 2.a. Simple Disconnection to A/B Sails 2.b. Simple Disconnection to CID Soils 2.c. To Soil Amended FiLr Path as per specifications (existing C/D soils) (Spec #4) 2 d To Dry Well or French Drain #1, 2.e. To Dry Well or French Drain #2, Micro -infiltration #2 (Spec #8) 2g. To Rain Garden #2, 2.h. To Rainwater Harvesting (Spec #6� 13. Permeable Pavement (RR) Is. Permeable Pavement 91 (Spec #71 It. Permeable Pavement #2 (Spec #71 4. Grass Channel (RR) 4.a. Grass Channel A/B Soils (Spec 43� 5. Dry Swale (RR) �6. Bioretention (RR) Nitrogen Nitrogen Load Untreated Nitrogen Remaining Removal from Upstream Nitrogen Load to Removed By Nitrogen Efficiency (%) Practices (Ibs) Practice (Ibs) Practice (Ibs) Load (Ibs) 0 0.00 0.00 0.00 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 3. Permeable Pavement (RR) 4. Grass Channel (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 1/6Iz020 8 or 25 8:43 AM 20.01.02 Keswick_Hall (Spa}VRRM_ReD- C—pliance_Spreadaheet_v3_052016 D.A. C 7. Infiltration (RR) 8. Extended Detention Pond (RR) 19. Sheetflow to Filter/Open Space (RR) 9.b. Sheetflow to Conservation Area, C/D Solis TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. C (ft') 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. C (lb/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. C (lb/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. C (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS - 10. Wet Swale (no RR) 1. Filtering Practices (no RR) 13. Wet Ponds (no RR) 60 0.00 0.00 0.00 0.00 7. Infiltration (RR) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. C (f[) 0 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. C (lb/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale Plain) RR) (Coastal (no 11. Filtering Practices (no RR) 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 1/6/2020 9 of 25 8:43 AM 20,01,02 K,—k_Hall (Spa)-VRRM_ReDev_C—pllance_Spreadsheet_v3_052016 D.A. C 14. Manufactured Treatment Devices RR) (no TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (Ib/yr) 1.28 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. C (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. C (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. C (Ib/yr 0.00 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. C (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. C (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. C (Ib/yr 0.00 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. C (Ib/yr 0.00 TOTAL NITROGEN REMOVED IN D.A. C (Ib/yr 0.00 14. Manufactured BMP (no RR) 1/6/2020 10 d 25 8:43 AM Drainage Area D nrainaee Area A i and rnver t.,r l A Soils B Soils C Soils D Soils Totals land Cover Rv Forest/Open Spam (acres) 0.00 0.00 Managed Turf (acres) 0.00 0.00 Impervious Cover (acres) 0.00 0.00 Total 0.00 Stormwater Rest Management Practices (RR = Runoff Reduction) 20.01.02 Keswick He (Spa)-VRRM_ReDev_Campliance_Spreadsheet _0 052016 CA.D Total Phosphorus Available for Removal in D.A. D (lb/yr) 0.00 Post Development Treatment Volume in D.A. D (fta) 0 __Gnln�r i.nm d.nndnwn lieie_ Runoff Managed Impervious Volumefrom Runoff Remaining Total BMP Phosphorus Untreated Phosphorus Phosphorus Remaining Practice Reduction Turf Credit Cover Credit Upstream Reduction Runoff Treatment Removal Load from Phosphorus Removed By Phosphorus Downstream Practice to be Credit (%) Area (acres) Area (acres) Practice (fta) (ft3) Volume (ft3) Volume (ft3) Efficiency (%) Upstream Load to Practice (lb) Load (lb) Employed Practices [lb) Practice (lb) 1.a. Vegetated Roof #1(Spec #5) 45 0 0 0 0 0.00 0.. 0.00 Lb. Vegetated Roof #2 (Spec #5) 60 0 0 0 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 2.a. Simple Disconnection to A/B Soils 2.b. Simple Disconnection to C/D Soils 2.c. To Soil Amended FiLr Path as per specifications (existing C/D soils) (Spec #4) 2.d. To Dry Well or French Drain #1, 2.e. To Dry Well or French Drain #2, Micro -infiltration #2 (Spec #8) 2g. To Rain Garden #2, 2.h. To Rainwater Harvesting (Spec #6� 13. Permeable Pavement (RR) Is. Permeable Pavement 91 (Spec #71 It. Permeable Pavement #2 (Spec #71 4. Grass Channel (RR) 4.a. Grass Channel A/B Soils (Spec 43� 4.b. Grass Channel C/D Soil, (Spec #3� 5. Dry Swale (RR) �6. Bioretention (RR) Nitrogen Nitrogen Load Untreated Nitrogen Remaining Removal from Upstream Nitrogen Load to Removed By Nitrogen Efficiency (%) Practices (Ibs) Practice (Ibs) Practice (Ibs) Load (Ibs) 0 0.00 0.00 0.00 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 3. Permeable Pavement (RR) 4. Grass Channel (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 1/6Iz020 11 or 25 8:43 AM 20.01.02 Keswick_Hall (Spa}VRRM_ReD- C—pliance_Spreadaheet_v3_052016 D.A. D 7. Infiltration (RR) 8. Extended Detention Pond (RR) 19. Sheetflow to Filter/Open Space (RR) 9.b. Sheetflow to Conservation Area, C/D Solis TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. D (fe) 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS - 10. Wet Swale (no RR) 1. Filtering Practices (no RR) 13. Wet Ponds (no RR) 60 0.00 0.00 0.00 0.00 7. Infiltration (RR) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. D (ft') 0 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale Plain) RR) (Coastal (no 11. Filtering Practices (no RR) 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 1/6/2020 12 of 25 8:43 AM 20.01.02 Keswick_Hall (Spa}VRRM_ReD- Compliance_Spreadah-t_v3_052016 D.A. D 114. Manufactured Treatment Devices RR) (no TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac)l 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (lb/yr) 1.28 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. D (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. D (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. D (Ib/yr 0.00 TOTAL NITROGEN REMOVED IN D.A. D (Ib/yr 0.00 14. Manufactured BMP (no RR) 1/6/2020 13 of 25 8:43 AM Drainage Area E nrainaee Area A i and rnver t.,r l A Soils B Soils C Soils D Soils Totals land Cover Rv Forest/Open Spam (acres) 0.00 0.00 Managed Turf (acres) 0.00 0.00 Impervious Cover (acres) 0.00 0.00 Total 0.00 Stormwater Rest Manaeement Practices (RR = Runoff Reduction) 20.01.02 Keswick He (Spa)-VRRM_ReDev_Campliance_Spreadsheet _0 052016 D.A. E Total Phosphorus Available for Removal in D.A. E (lb/yr) 0.00 Post Development Treatment Volume in D.A. E (fta) 0 __Gnln�r i.nm d.nndnwn lieie_ Runoff Managed Impervious Volumefrom Runoff Remaining Total BMP Phosphorus Untreated Phosphorus Phosphorus Remaining Practice Reduction Turf Credit Cover Credit Upstream Reduction Runoff Treatment Removal Load from Phosphorus Removed By Phosphorus Downstream Practice to be Credit (%) Area (acres) Area (acres) Practice (fta) (ft3) Volume (ft3) Volume (ft3) Efficiency (%) Upstream Load to Practice (lb) Load (lb) Employed Practices(lb) Practice(lb) 1.a. Vegetated Roof #1(Spec #5) 45 0 0 0 0 0.00 0.. 0.00 Lb. Vegetated Roof #2 (Spec #5) 60 0 0 0 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 2.a. Simple Disconnection to A/B Soils 2.b. Simple Disconnection to C/D Soils 2.c. To Soil Amended FiLr Path as per specifications (existing C/D soils) (Spec #4) 2.d. To Dry Well or French Drain #1, 2.e. To Dry Well or French Drain #2, Micro -infiltration #2 (Spec #8) 2g. To Rain Garden #2, 2.h. To Rainwater Harvesting (Spec #6� 13. Permeable Pavement (RR) Is. Permeable Pavement 91 (Spec #71 It. Permeable Pavement #2 (Spec #71 4. Grass Channel (RR) 4.a. Grass Channel A/B Soils (Spec 43� 4.b. Grass Channel C/D Soils (Spec #3� 5. Dry Swale (RR) �6. Bioretention (RR) Nitrogen Nitrogen Load Untreated Nitrogen Remaining Removal from Upstream Nitrogen Load to Removed By Nitrogen Efficiency (%) Practices (Ibs) Practice (Ibs) Practice (Ibs) Load (Ibs) 0 0.00 0.00 0.00 0 0.00 0.00 0.00 2. Rooftop Disconnection (RR) 3. Permeable Pavement (RR) 4. Grass Channel (RR) 5. Dry Swale (RR) 6. Bioretention (RR) 1/6Iz020 14 or 25 8:43 AM 20.01.02 Keswick_Hall (Spa}VRRM_ReD- C—pliance_Spreadaheet_v3_052016 D.A. E 7. Infiltration (RR) 8. Extended Detention Pond (RR) 19. Sheetflow to Filter/Open Space (RR) 9.b. Sheetflow to Conservation Area, C/D Solis TOTAL IMPERVIOUS COVER TREATED(ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL RUNOFF REDUCTION IN D.A. E (ft') 0 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. E (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. E (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACTICES IN D.A. E (lb/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS - 10. Wet Swale (no RR) 1. Filtering Practices (no RR) 13. Wet Ponds (no RR) 60 0.00 0.00 0.00 0.00 7. Infiltration (RR) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to Filter/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. E (ft') 0 NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. E (lb/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (Information Only) 10. Wet Swale Plain) RR) (Coastal (no 11. Filtering Practices (no RR) 12. Constructed Wetland (no RR) 13. Wet Ponds (no RR) 1/6/2020 15 of 25 8:43 AM 20,01,02 K.—k_Hall (Spa)-VRRM_ReDev_Compliance__Spreadsheet_v3_052016 D.A. E 14. Manufactured Treatment Devices RR) (no TOTAL IMPERVIOUS COVER TREATED (ac) 0.00 AREA CHECK: OK. TOTAL MANAGED TURF AREA TREATED (ac) 0.00 AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (Ib/yr) 1.28 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. E (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. E (Ib/yr 0.00 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. E (I"yr 0.00 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. E (Ib/yr 0.00 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. E (Ib/yr 0.00 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICES IN D.A. E (Ib/yr 0.00 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN D.A. E (Ib/yr 0.00 TOTAL NITROGEN REMOVED IN D.A. E (Ib/yr 0.00 14. Manufactured BMP (no RR) 1/6/2020 16 d 25 8:43 AM Site Results (Water Quality Compliance) NIANAGED TURF AREA Site Treatment Volume Runoff Reduction Volume and TP By Drainage A RUNOFF TP DAD AVNLABLE FOR REMOVAL (it TPLOADNEDUMONAOUIEVED la TP LOAD REMAINING (it NITROGEN LOAD REDUMON FD ph Total Phosphor INATP AD (it LOAD REDUCTION REQUIRED pt TP LOAD EDUCTION ACHIEVED (it TP LOAD REMAINING III, IIb, Total Nitrogen (For Information Purpos 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 Total Rainfall (in): 43 Total Disturbed Acreage: 2.02 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) A soils B Soils C Soils D Soils 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) 0.00 0.00 0.00 0.57 0.57 28 2.02 100 Post-ReDevelopment Land Cover (acres) A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.94 0.94 47 Impervious Cover (acres) 0.00 0.00 0.00 1.08 1.08 53 2.02 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post Post- Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment & New Im Impervious) p ) (New Impervious) Site Rv 0.62 0.51 0.95 0.50 Treatment Volume (ft) 4,577 2,819 1,759 2,761 TP Load (lb/yr) 1 2.88 1.77 1.11 1.73 Total TP Load Reduction Required (lb/yr) 1.28 0.38 0.90 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (lb/yr) 20.57 12.82 Site Compliance Summary Maximum % Reduction Required Below 20% Pre-ReDevelopment Load 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) 1.15 1.42 1.17 Summary Print Virginia Runoff Reduction Method Worksheet Total Runoff Volume Reduction (ft) 716 Total TP Load Reduction Achieved (lb/yr) 0.55 Total TN Load Reduction Achieved (lb/yr) 4.09 Remaining Post Development TP Load 2.33 (lb/yr) Remaining TP Load Reduction (lb/yr) Required 0.73 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) 0.39 0.55 0.00 0.00 0.00 0.94 Impervious Cover (acres) 0.70 0.38 0.00 0.00 0.00 1.08 Total Area (acres) 1.09 0.93 0.00 0.00 0.00 2.02 Drainage Area Compliance Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total TP Load Reduced (lb/yr) 0.55 0.00 0.00 0.00 0.00 0.55 TN Load Reduced (lb/yr) 4.09 0.00 0.00 0.00 0.00 4.09 Drainage Area A Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.39 0.39 36 Impervious Cover (acres) 0.00 0.00 0.00 0.70 0.70 64 1.09 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I 3 Volume (ft) Upstream to Practice (Ibs) (lb/yr) (lb/yr) to be Employed (acres) Area (acres) Practices (Ibs) Total Impervious Cover Treated (acres) 0.31 Total Turf Area Treated (acres) 0.00 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. 0.55 (lb/yr) Total TN Load Reduction Achieved in D.A. 4.09 (lb/yr) Drainage Area B Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.55 0.55 59 Impervious Cover (acres) 0.00 0.00 0.00 0.38 0.38 41 0.93 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I 3 Volume (ft) Upstream to Practice (Ibs) (Ib/yr) (Ib/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 C Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I 3 Volume (ft) 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 Summary Print Virginia Runoff Reduction Method Worksheet 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 A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I 3 Volume (ft) Upstream to Practice (Ibs) (Ib/yr) (Ib/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. (Ib/yr) 0.00 Drainage Area E Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit I 3 Volume (ft ) 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 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Runoff Volume and CN Calculations 1-year storm 2-year storm 30-year storm Target Rainfall Event (in) 1 2.92 3.54 5.35 Drainage Areas RV & CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN 92 87 0 0 0 RR (ft) 716 0 0 0 0 1-year return period RV wo RR (-in) 2.09 1.67 0.00 0.00 0.00 RVwRR(ws-in) 1.90 1.67 0.00 0.00 0.00 CN adjusted 90 87 0 0 0 2-year return period RV wo RR (ws-in) 2.68 2.22 0.00 0.00 0.00 RV w FIR (ws-in) 2.49 2.22 0.00 0.00 0.00 CN adjusted 90 87 0 0 0 10-year return period RV wo RR (ws-in) 4.43 3.90 0.00 0.00 0.00 RV w RR (ws-in) 4.25 3.90 0.00 0.00 0.00 CN adjusted 90 87 0 0 0 Summary Print 20.01.02 Keswick —Hall (Spa)-VRRM_ReDev_Compliance_Spreadsheet_v3_052016 Version 2.8 - June 2014 - 2011 BMP Stds & Specs 1 Fixed summary sheet - totals /percentage column fixed 2 Corrected nitrogen efficiency percentages 3 Corrected the Rv value in column J for managed turf 4 Checked and revised runoff reduction credit values assigned Version 3.0 - 2011 and draft 2013 BMP Stds & Specs General 1 Added error checks 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. Site tab 5 Locked annual rainfall 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 phosporus load reduction requirement. Previous formula was inconsistent with 9VAC25-870-63 A.2 and under certain circumstances provided erroneous TP load reduction requirement for development on prior developed lands. 7 Added button and shortcut (Ctrl+Shift+R) to clear user inputs from all worksheets. 8 Added shortcut (Ctrl+Shift+D) to clear land cover data from Site tab. 9 Added TP Baseline Load for adjusted pre-redevelopement portion (cell C58). 10 Added note (triggered to appear when applicable) below "Land Cover Summary for Redevelopment'- indicating that reduction below baseline TP load (<0.41 Ibs/acre) not required as per 9VAC25-870-63. 11 Added error messages when data input areas incomplete or not entered correctly. 12 Conditional formatting (Summary sections grayed out) when input information incomplete or incorrect. 13 Added Pre -redevelopment and Post -development load in Ibs/acre/yr (row 57) for additional comparison purposes 14 Corrected error in excel formula for new impervious cover Rv. 15 Corrected errors in excel formula for total site area and Rv's in redevelopment portion: error appeared when soil types change between pre -redevelopment and post -development 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 new net impervious cover portion. 17 Added informational section in blue (columns B to F, rows 12-14) and input/error guide (columns H to K, rows 12-14) to indicate to users upfront when new net impervious cover is being triggered, when 10 or 20 % reductions are being utilized, and when 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 D64-G64) D.A. tabs 20 Added MTDs: Hydrodynamic, Filtering, Generic. 21 Added "Total BMP Treatment Volume (W)" column. 22 Rearranged previous Turf and Impervious input rows 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 practice to identify those with and without Runoff Reduction. 24 Added " Total Phosphorus Available for Removal in D.A. _ (Ibs)". 25 Added button to clear BMP credit areas entered for each practice. 26 Added user prompts to assist with user -input Rainwater Harvesting runoff reduction credit, and MTDs. 27 Renamed Credit and Phosphorus/Nitrogen Efficiency column headers to Runoff Removal Credit and Phosphorus/Nitrogen Removal Efficiency for clarity. 28 Removed "RR" from Column headings referring to runoff volume and TP load from upstream practices (which may be RR or non -RR practices). 29 Renamed "l 0. Wet Swale (Coastal Plain)" to "10. Wet Swale" in BMP heading in order to improve clarity. The practice is well suited for but not limited to the Coastal Plain. 30 Renamed "14. Manufactured BMPs" section heading to "14. Manufactured Treatment Device"s for consistency with Virginia BMP Clearinghouse. 31 Added "Micro-Bioretention #1" and "Micro-Bioretention #2" to Bioretention 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 Quality Compliance tab 33 Optimized and reorganized for improved information output. 34 Added "Runoff Reduction Volume and TP By Drainage Area". 35 Added section for linear development projects (rows 21-26) Runoff Volume and CN tab 36 Reorganized and renamed Channel and Flood Protection tab to Runoff Volume and CN to more accurately reflect information provided. 37 Added user notes regarding limitations of Runoff Volume and CN tab for water quantity calculations. 38 Renamed CNw i,ihred to CNio.A. xl for the CNs based on soils and land cover types for each drainage area Summary tab 39 Added "Print Preview" button. 40 Fixed runtime error in Summary tab update macro. 41 Added "BMP Treatment Volume", "TP Load from Upstream practice", 7P Removed" and "TP remaining" columns to Summary tab. 42 Optimized macro efficiency and eliminated screen updating/flashing during macros. 43 Corrected Summary tab macro -Turf missing routine missing "<>". 44 Added additional pre and post site data onto Summary tab. 45 Added Error Summary Table to Summary tab (appears only if errors on Site tab or Drainage Area tabs are present) 46 Expanded and improved Runoff Coefficient and CN calculation section. 47 Added summary information for linear projects, only populates if applicable. 4S 13L Pre Area 1-1 (Offsite) Areas Combined (1-1 + 1-2 ) 12S Pre Area 1-2 (Onsite) S4 Reach on Link Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.780 83 VRRM SPREADSHEET D.A. A (4S) 2.020 87 VRRM SPREADSHEET D.A. B (12S) 2.800 86 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 0.000 HSG D 2.800 Other 4S, 12S 2.800 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Printed 1/6/2020 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 0.000 0.780 0.780 VRRM SPREADSHEET D.A. A 4S 0.000 0.000 0.000 0.000 2.020 2.020 VRRM SPREADSHEET D.A. B 12 S 0.000 0.000 0.000 0.000 2.800 2.800 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Type 1124-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 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=0.780 ac 0.00% Impervious Runoff Depth>1.38" Tc=7.0 min CN=83 Runoff=1.83 cfs 0.090 of Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 0.00% 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=7.48 cfs 0.370 of Primary=7.48 cfs 0.370 of Total Runoff Area = 2.800 ac Runoff Volume = 0.370 of Average Runoff Depth = 1.59" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 1.83 cfs @ 11.99 hrs, Volume= 0.090 af, Depth> 1.38" 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 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious 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) --------- ------ I I I I I I I 1 IType Ili 24-hr 61 1-`�R; RainfalllL 2.021 'Runoff Awea=0.780 ad Runoff llVolume=0.090 of - ]t-u;ngf Depth-1 '$816. I I Tc=7.10 Min I 1 CN:;=83 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) Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 7 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 2.020 87 VRRM SPREADSHEET D.A. B 2.020 100.00% Pervious 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 -T-1--7-1- 6 IfiII- I I I I 5 I rt l l l I t I l l fi I l i I 4 N ( I I I I I I I I 1+1t11� 0 3 1 1 LL 2 - 1 I I I I I I I I I I I -7-1-F7-I-T -1-7-1-F7-I- 5.65 cfs 1 1 1 1 1Tyrpe Ili 24-hr 1-`F " RainfallT2.02, 1 1Runbff MeA=2.020 arc I r- I I rt 1 t--1 I 1 1 Runoff lVolumle=;0.281 of I off( 1 1 1 1 I 11.tTcc� 7.10 M i n I I I I I I I I I I I -1-1---4-1-+-1-- N-7-87- 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) Type 11 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 8 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 1.59" for 1-YR event Inflow = 7.48 cfs @ 11.98 hrs, Volume= 0.370 of Primary = 7.48 cfs @ 11.98 hrs, Volume= 0.370 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 13L: Areas Combined (1-1 + 1-2) Hydrograph 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) ■ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (PRE) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 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=0.780 ac 0.00% Impervious Runoff Depth>1.89" Tc=7.0 min CN=83 Runoff=2.49 cfs 0.123 of Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 0.00% 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 = 2.800 ac Runoff Volume = 0.496 of Average Runoff Depth = 2.12" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 2.49 cfs @ 11.98 hrs, Volume= 0.123 af, Depth> 1.89" 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 2-YR Rainfall=3.54" Area (ac) CN Description 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, 2 0 Subcatchment 4S: Pre Area 1-1 (Offsite) Hydrograph I I I I I I I ' ' I I I I .49 cfs 1 IType Ili 24-hr - _ainf;1IIT3..541' 'Runbff Awea=0.780 arc I I I I I I Runoff lVolume=0.123 of Ou;noff'IDepth>1.,091' Tc=7.'0 Min L L _ I_ L _I_ 1 CN:;=83 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) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 11 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 2.020 87 VRRM SPREADSHEET D.A. B 2.020 100.00% Pervious 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 I I I I I I I I I I I I I I I I I I I I I I I 8 I I I I I I I I I I I I I I I I I I I I I I I 7.a3 cfs Type Ai24-hr 7 1 1 1 1 1 `. — — —I 1 Rainf0IIT3541 6 " " " 'RunbfP Ate6=2.020 at I I I I I I I I I I I I I I I I I I I I I I 5 1 1 1 1 1-Runoff VolumemO-.373af -I- T —11 *InOftllDepth>-2,1__21 U y� 0 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Tc=7.'0 Mill 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CN:;:87 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I I I I I I I I I I I I I I I I �1rt1-fi11rt1rt--�-1-- rt1 1 1 1 1 1 1 1 1 1 1 1 1 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) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 12 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 2.12" 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 F f Link 13L: Areas Combined (1-1 + 1-2) Hydrograph 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) F Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (PRE) Type // 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 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=0.780 ac 0.00% Impervious Runoff Depth>3.49" Tc=7.0 min CN=83 Runoff=4.49 cfs 0.227 at Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.020 ac 0.00% 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=17.16 cfs 0.882 of Primary=17.16 cfs 0.882 of Total Runoff Area = 2.800 ac Runoff Volume = 0.882 of Average Runoff Depth = 3.78" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type 11 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 4.49 cfs @ 11.98 hrs, Volume= 0.227 af, Depth> 3.49" 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 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious 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 —1- 5 4.49 cfs 1 1 I 1 1 1 1Tyrpe Ili 24-hr ? r 1� 4 0-`�F F�lainfall 5. 57 'Runbff Awea=0.780 ad I I I I I I I I I I I I I 3 1-Runoff of N I 1 tu;nOff'IDepth>3.�491, U o I I 1 1 1 1_Tc7- 7 .'0 M1 ft LL 2 CN�83 I I I 1 I I I I I I l I I I I I I i t 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) ■ Runoff Keswick Hall_Spa_Analysis Points 1 (PRE) Type 11 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 15 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 2.020 87 VRRM SPREADSHEET D.A. B 2.020 100.00% Pervious Area Tc (min) Length (feet) Slope (ft/ft) Velocity (ft/sec) Capacity (cfs) Description 7.0 Direct Entry, Subcatchment 12S: Pre Area 1-2 (Onsite) Hydrograph — I— —1— 4- —1 — -4 — I— —1— 4- —1— 4- —1 — r 1 - + —1— —1 — 14 — — _ _—_ _— __ _ — — ■Runoff 13 I I I I 7 1 I I I I T 1 F-1 1 1 1 7 12ds I I I I I I �yI I I I 1 1 T F--i 1Ty ppe]IT24� 12 � —I— � —I— � —I— l I I I— �- I �% I— �rin � � 11 11� 1- RAWO11T5 1 10 — — — — — — — — — — — — — — - — — — — — — — — — — — — — — RunbfP MeA=2.020 at rt rt fi r rt fi 1 [- I —II— t—I—tII r- 9 -1 1 1-1-L 1 1 -1 11 1 1RurtoffLVb1u_ ne=;0.655-af 8 1 1 — 1 1 —1— 1 1 1 1 —I — 1 1 — —I 1 I#ID p1�0961 7 o I— 1 ' � 1 I— 1 `f I� T� 111111 LL 6 1 1 1 5 — — — — — — — — — — — — — — — 4 1 7 1 1 1 1 1 1 7 1 T I -4I1ILI AI1I IIk- -4I1I4--I� 3 2 I I I I I I I I I I I I -1 — 1— 7 —1— -r - I I I I —F- 1 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) Type 11 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 16 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 3.78" for 10-YR event Inflow = 17.16 cfs @ 11.98 hrs, Volume= 0.882 of Primary = 17.16 cfs @ 11.98 hrs, Volume= 0.882 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 / fi fi I f —t 17.1 B cfs 18 rt -1- 1— rt -1- 7,6cfs _1nf1olwfiAree=2-.1800- ac 17 / rt I fi I I rt I t— rt I— I rt I fi� I rt I r� 16 / 15 rt l l rt i rt l 14 / 13 12 11 `—' 10 / 0 9 / 1 1 1 1 1 1 LL 8 / 1 7 /-T 1 g / 5 / 4 / 3 / 2 / 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) F Inflow ❑ Primary 1S Post Area 1-3 (Offsite, 17S detained) 19P 2S \ n Post Area 1-5 (Onsite, SWM 3 7� 18L Undetained) Post Area 1-4 (Onsite, Detained) Areas Combined SubCat Reach On Link n Diagram for Keswick Hall_Spa_Analysis Points 1 (POSTPrepared by Timmons Group, Printed 1/6/2020 D® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Keswick Hall_Spa_Analysis Points 1 (POST) Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.780 83 VRRM SPREADSHEET D.A. A (1S) 1.090 91 VRRM SPREADSHEET D.A. B (2S) 0.930 87 VRRM SPREADSHEET D.A. D (17S) 2.800 87 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST) Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 0.000 HSG D 2.800 Other 1 S, 2S, 17S 2.800 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST) Prepared by Timmons Group HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Printed 1/6/2020 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 0.000 0.780 0.780 VRRM SPREADSHEET D.A. A 1 S 0.000 0.000 0.000 0.000 1.090 1.090 VRRM SPREADSHEET D.A. B 2S 0.000 0.000 0.000 0.000 0.930 0.930 VRRM SPREADSHEET D.A. D 17 S 0.000 0.000 0.000 0.000 2.800 2.800 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST) Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 5 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) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 6 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=0.780 ac 0.00% Impervious Runoff Depth>1.38" Tc=7.0 min CN=83 Runoff=1.83 cfs 0.090 of Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=1.090 ac 0.00% Impervious Runoff Depth>1.99" Tc=6.0 min CN=91 Runoff=3.63 cfs 0.181 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=0.930 ac 0.00% Impervious Runoff Depth>1.67" Tc=6.0 min CN=87 Runoff=2.65 cfs 0.129 al Pond 19P: SWM 3 Peak Elev=425.29' Storage=0.051 of Inflow=5.39 cfs 0.271 of Outflow=2.55 cfs 0.271 of Link 18L: Areas Combined Inflow=4.92 cfs 0.400 of Primary=4.92 cfs 0.400 of Total Runoff Area = 2.800 ac Runoff Volume = 0.400 of Average Runoff Depth = 1.71" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST) Type // 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 1.83 cfs @ 11.99 hrs, Volume= 0.090 af, Depth> 1.38" 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 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1 S: Post Area 1-3 (Offsite, detained) -------- ---- I I I I I I 1 IType Ili 24-hr 117Yr1 Rainfall 2.021 1Run6ff Awea=0.780 ad Runoff llVolume=0.090 of - ]t-u;ngffllDeptl$-1 $816' I I Tc=7.10 Min I 1 CN:;=83 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) Type // 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 3.63 cfs @ 11.97 hrs, Volume= 0.181 af, Depth> 1.99" 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 1.090 91 VRRM SPREADSHEET D.A. B 1.090 100.00% Pervious 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 -4-1—+—I-4--1-1—-4—I—+—I-4- --4—I—+-1—1—-4—I- 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ❑Runoff 3-6 ds I I I I I 1 1 1 1 1 1Type Ili 24-hr -1- 7 -11 — r -i - 11- -T - 1 I � ��Xlit �1ai nfalf 1 .02�. 3 1 1 1 1 1 1 1 1 1 1 'Runbff Awea=1.090 ad Runoff lVolume=0.181 of R-unoff 1 a 2- I I Tc=6.10 Min LL I I 1 CN:;:91 1 1 1 1 1 1 1 1 1 1 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) Type // 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 2.65 cfs @ 11.97 hrs, Volume= 0.129 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 0.930 87 VRRM SPREADSHEET D.A. D 0.930 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, N U 3 0 LL 2 0 Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Hydrograph I I I I I I I I I I (Type Ili 24-hr 61 117Yr1 Rainfall--' 2.021 Runoff Alyea=0-.930 a& I I I I I I Runoff lVolume=0.129 of Ru;noff'IDepth>1.,0716' I I Tc=6.10 Min 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 (POST) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 10 Summary for Pond 19P: SWM 3 Inflow Area = 1.870 ac, 0.00% Impervious, Inflow Depth > 1.74" for 1-Yr event Inflow = 5.39 cfs @ 11.97 hrs, Volume= 0.271 of Outflow = 2.55 cfs @ 12.08 hrs, Volume= 0.271 af, Atten= 53%, Lag= 6.4 min Primary = 2.55 cfs @ 12.08 hrs, Volume= 0.271 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 425.29' @ 12.08 hrs Surf.Area= 0.020 ac Storage= 0.051 of Plug -Flow detention time= 5.3 min calculated for 0.271 of (100% of inflow) Center -of -Mass det. time= 5.2 min ( 818.0 - 812.8 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 T Device Routinq 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 7' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 7.5" 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=2.54 cfs @ 12.08 hrs HW=425.26' (Free Discharge) 1=Culvert (Passes 2.54 cfs of 10.65 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.54 cfs @ 8.27 fps) L4=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate ( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST) Type // 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 11 Pond 19P: SWM 3 Hydrograph - 6 5.39 ds -1- - I- t -1- -t -1--Ilnflow (Area=1.870tac I 5 I I I I I I I I I I I I I I I Pea1k Elevr=42I15.29' 1 1 1 1 1 1 - I- 1-+-1- 4 - I - I I0.0�1+af Stora 4 N c3 2 55 cfs LL 1 _I_ L J_ I_ 1 —1 _ L 1 _ L 1 _1_ L J_ I I 2 " l 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 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) ■ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 12 Summary for Link 18L: Areas Combined Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 1.71" for 1-Yr event Inflow = 4.92 cfs @ 11.99 hrs, Volume= 0.400 of Primary = 4.92 cfs @ 11.99 hrs, Volume= 0.400 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs N V 3 0 LL Link 18L: Areas Combined Hydrograph 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) ❑ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 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 Subcatchment1S: Post Area 1-3 (Offsite, Runoff Area=0.780 ac 0.00% Impervious Runoff Depth>1.89" Tc=7.0 min CN=83 Runoff=2.49 cfs 0.123 of Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=1.090 ac 0.00% Impervious Runoff Depth>2.58" Tc=6.0 min CN=91 Runoff=4.62 cfs 0.234 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=0.930 ac 0.00% Impervious Runoff Depth>2.22" Tc=6.0 min CN=87 Runoff=3.49 cfs 0.172 al Pond 19P: SWM 3 Peak Elev=425.79' Storage=0.061 of Inflow=7.03 cfs 0.357 of Outflow=5.60 cfs 0.357 of Link 18L: Areas Combined Inflow=8.02 cfs 0.529 of Primary=8.02 cfs 0.529 of Total Runoff Area = 2.800 ac Runoff Volume = 0.529 of Average Runoff Depth = 2.27" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 2.49 cfs @ 11.98 hrs, Volume= 0.123 af, Depth> 1.89" 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 2-YR Rainfall=3.54" Area (ac) CN Description 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, 2 0 Subcatchment 1 S: Post Area 1-3 (Offsite, detained) Hydrograph .49 cfs 1 IType Ili 24-hr - _ainf;1IIT3..541' 1Run6ff Awea=0.780 arc I I I I I I Runoff lVolume=0.123 of Ou;noff'IDepth>1.,091' Tc=7.10 Min L —1 — I_ L _I_ 1 CN:;=83 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 (POST) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 15 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 4.62 cfs @ 11.97 hrs, Volume= 0.234 af, Depth> 2.58" 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 1.090 91 VRRM SPREADSHEET D.A. B 1.090 100.00% Pervious 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 I I I I I I I I I I I I I I I I — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4.62 cfs I I I I I I I 1 1 I 1 1Tyrpe Ili 24-hr 4 1 1 1 1 1 1 1 Rair1 a11TJ. 41 1 1 1Runbff Awea=1.090 at I I I I I I I I I I I I I I I -I- t -1 -Run-offiVolume=O-.2-34-af N 3 uinOff 11Depth>2.15$l. U 0 1 1 1 1 1 TC=�.10 ftlih 2,1i1 i 1i 1i i CN�9� 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) ■ Runoff Keswick Hall_Spa_Analysis Points 1 (POST) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 16 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 3.49 cfs @ 11.97 hrs, Volume= 0.172 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 0.930 87 VRRM SPREADSHEET D.A. D 0.930 100.00% Pervious 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) — — I I I I — 1 I I I I I I I L 1 I I I I I I - 3 I I I I I I I I I I I I I I I I w I _ I I I I_ 1 _ I I I _ L _I I I _ 1_ -1 2 3 o I LL A I 1 1 L 1 I - 1 I I I I I I I I I I I I I I I I I I I I I Hydrograph I I I I I I I I ' ❑Runoff 3.49 cfs I I I 1Tyrpe III 24-h r 2=` Rllairifalt.54 1Run6ff Awea=0.930 ad Runoff llVolume=0.172 of -0-u;npff IIDepth>-2-.# I I I I Tc=6.10 Min CN:;=87 — L 1 1— — — - 1 1 1 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) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 17 Summary for Pond 19P: SWM 3 Inflow Area = 1.870 ac, 0.00% Impervious, Inflow Depth > 2.29" for 2-YR event Inflow = 7.03 cfs @ 11.97 hrs, Volume= 0.357 of Outflow = 5.60 cfs @ 12.04 hrs, Volume= 0.357 af, Atten= 20%, Lag= 4.2 min Primary = 5.60 cfs @ 12.04 hrs, Volume= 0.357 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 425.79' @ 12.04 hrs Surf.Area= 0.019 ac Storage= 0.061 of Plug -Flow detention time= 5.3 min calculated for 0.357 of (100% of inflow) Center -of -Mass det. time= 5.2 min ( 810.5 - 805.4 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 T Device Routinq 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 7' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 7.5" 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=5.41 cfs @ 12.04 hrs HW=425.77' (Free Discharge) 1=Culvert (Passes 2.75 cfs of 11.67 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.75 cfs @ 8.95 fps) L4=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 2.66 cfs @ 2.22 fps) Keswick Hall_Spa_Analysis Points 1 (POST) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 18 Pond 19P: SWM 3 Hydrograph I I rt I I I I L-1 I I I T 1 I I I I I I I I I I I I I I I F-T �.oa 1 T 1 F-1 I F 1 T 1 Inflow 7 1 1 1 1 1 (Area=1.8701ac -1- -I- _11 _ _ _ 11- Peak lev% 42115.E 9-' 1 1_ 6 sso cfs i I I I I I I - MarageT( a 1 1 1 .06 5 1 1 1 1 1 1 1 1 1 t I t 1 -i I t--1I t 1 1 4 c -11 L L L 1 1 L 1 L-1 I L-1 L 3 2 4 —1— + + — I— + —1 — F t —1 — 4 —1— -1 — I— + —1 — 1 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) ■ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Link 18L: Areas Combined Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 2.27" for 2-YR event Inflow = 8.02 cfs @ 12.02 hrs, Volume= 0.529 of Primary = 8.02 cfs @ 12.02 hrs, Volume= 0.529 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 18L: Areas Combined Hydrograph 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) ■ Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type // 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 20 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=0.780 ac 0.00% Impervious Runoff Depth>3.49" Tc=7.0 min CN=83 Runoff=4.49 cfs 0.227 A Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=1.090 ac 0.00% Impervious Runoff Depth>4.32" Tc=6.0 min CN=91 Runoff=7.50 cfs 0.392 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=0.930 ac 0.00% Impervious Runoff Depth>3.89" Tc=6.0 min CN=87 Runoff=5.96 cfs 0.302 al Pond 19P: SWM 3 Peak Elev=426.96' Storage=0.079 of Inflow=11.87 cfs 0.619 of Outflow=11.36 cfs 0.619 of Link 18L: Areas Combined Inflow=17.01 cfs 0.921 of Primary=17.01 cfs 0.921 of Total Runoff Area = 2.800 ac Runoff Volume = 0.921 of Average Runoff Depth = 3.95" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST) Type/1 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 4.49 cfs @ 11.98 hrs, Volume= 0.227 af, Depth> 3.49" 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 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1 S: Post Area 1-3 (Offsite, detained) Hydrograph —1—rt-1- 5 4.4s cfs 1 1 I I I I 1Tyrpe III 24-h r — 4 1— T -I - r -1- 1 107Yr Rainfall ' 5. I • 'Runbff Awea=0.780 ad I I I I I I I I I I I I I 3-Runoff of N I 1 tu;nOff IlDepth>3.�491, U o I I 1 1 1 1_Tc7-7.10of LL 2 CN�83 I I I 1 I I I I I I l I I I I I I i t 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) ■ Runoff Keswick Hall_Spa_Analysis Points 1 (POST) Type/1 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 7.50 cfs @ 11.96 hrs, Volume= 0.392 af, Depth> 4.32" 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 1.090 91 VRRM SPREADSHEET D.A. B 1.090 100.00% Pervious 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 8 zso ors 1 + +-Type *-24-hr 7 1 1 1 I 101Yr Railnf II 15- 5 6 1 1 1 1 1Runbff Ate6=1.090 arc I I I I I I I I I I I I I I I I I I 5 1 -1- T -I- i I I I-RunoffiVolume=0-292-a1r ulnc ff 11 De ft>4--�21- U 0 4 1 1 1 1 1 1 1 1 1 1 1 1 1 Tc�6.10 tnih u —1_1_1_I_1 I I I _LJ_I_—L_II- 3 1 1 1 1 1 1 1 1 1 CN:;:91 2 — —I— I —I— - — I —I— — I —I- 1I 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) Type/1 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 23 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 5.96 cfs @ 11.97 hrs, Volume= 0.302 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 0.930 87 VRRM SPREADSHEET D.A. D 0.930 100.00% Pervious 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 ■ Runoff 5.96 cfs 6 I I i ITyrpe Ili 24-hr 5 I — I— T —I— I —I — j 07YFI Rai infol I- 'Runbff Atecl=0.930 ad I I I I I I I I I I 4 1 I- RunofflVol-Runoff of N ungff'IDgp�h>3.,091' U LL 3 - I- -I-Tc:�6.10 �nii� CN�87 — — 1 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) Type/1 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 24 Summary for Pond 19P: SWM 3 Inflow Area = 1.870 ac, 0.00% Impervious, Inflow Depth > 3.97" for 10-Yr event Inflow = 11.87 cfs @ 11.97 hrs, Volume= 0.619 of Outflow = 11.36 cfs @ 12.00 hrs, Volume= 0.619 af, Atten= 4%, Lag= 1.9 min Primary = 11.36 cfs @ 12.00 hrs, Volume= 0.619 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 426.96' @ 12.00 hrs Surf.Area= 0.010 ac Storage= 0.079 of Plug -Flow detention time= 4.8 min calculated for 0.619 of (100% of inflow) Center -of -Mass det. time= 4.7 min ( 795.3 - 790.6 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP_Round 60" L= 180.0' S= 0.0033 T Device Routinq 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 7' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 422.00' 7.5" 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=11.22 cfs @ 12.00 hrs HW=426.94' (Free Discharge) 1=Culvert (Passes 4.11 cfs of 13.75 cfs potential flow) L2=Orifice/Grate (Orifice Controls 3.18 cfs @ 10.36 fps) 4=Sharp-Crested Rectangular Weir(Weir Controls 0.93 cfs @ 1.61 fps) 3=Orifice/Grate (Orifice Controls 7.11 cfs @ 5.69 fps) Keswick Hall_Spa_Analysis Points 1 (POST) Type/1 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 25 Pond 19P: SWM 3 Hydrograph / ■ Inflow 13 11.87 0 Primary 12 -I�flowt� 1ATea Mac � — 1 — fi —I — 1- � — I — � � 11.36 cfs I '�.8 PeIk IIc II evI =�IL�a� I.4V 10/7 -I- T -1 1- 7 -I- >- -T I 9 ztoraaeFuLS�of r 8 I I N / 7- 2 g - - - - - - - - - - - - - - - - - - - - - - a / 5 -T L I I rt 1 F� I I I I I I I 3 I / 2 t i 1 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) Type 11 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 26 Summary for Link 18L: Areas Combined Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 3.95" for 10-Yr event Inflow = 17.01 cfs @ 11.99 hrs, Volume= 0.921 of Primary = 17.01 cfs @ 11.99 hrs, Volume= 0.921 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 Hydrograph 7 - - T- -1 - F -T F -T T -1 - - - - 1- T - - 1- T -1 - F- -I 19 , 7 I T I F 7 I F� n.o, as I I T--17 1 F-1 18 j 7 -1- T--1 _ 1_ -T -I- F -T 17o,cfs nflowT/`/� rea=Z.BWac'r 17 16 7 T 1 F 7 F-T 7 7-1 T 1 F- 7 1 15 14 1 F 1 F 1 1 1 7 1 13 11 1 1 1 1 1 1 1 1 1 1 1 12 F 1 N 11 i F 1 10 o g LL g 7 g 5 i 121 1 4 3 i —1 1 1 2 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) F Inflow ❑ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type // 24-hr 100-YrRainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 27 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=0.780 ac 0.00% Impervious Runoff Depth>6.74" Tc=7.0 min CN=83 Runoff=8.35 cfs 0.438 ai Subcatchment2S: Post Area 1-4 (Onsite, Runoff Area=1.090 ac 0.00% Impervious Runoff Depth>7.71" Tc=6.0 min CN=91 Runoff=12.90 cfs 0.700 of Subcatchment17S: Post Area 1-5 (Onsite, Runoff Area=0.930 ac 0.00% Impervious Runoff Depth>7.22" Tc=6.0 min CN=87 Runoff=10.63 cfs 0.560 of Pond 19P: SWM 3 Peak Elev=427.81' Storage=0.081 of Inflow=21.05 cfs 1.138 of Outflow=21.60 cfs 1.138 of Link 18L: Areas Combined Inflow=32.23 cfs 1.698 of Primary=32.23 cfs 1.698 of Total Runoff Area = 2.800 ac Runoff Volume = 1.698 of Average Runoff Depth = 7.28" 100.00% Pervious = 2.800 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment 1S: Post Area 1-3 (Offsite, detained) Runoff = 8.35 cfs @ 11.98 hrs, Volume= 0.438 af, Depth> 6.74" 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 100-Yr Rainfall=8.80" Area (ac) CN Description 0.780 83 VRRM SPREADSHEET D.A. A 0.780 100.00% Pervious 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 I l l i l l l l l l l l l l l l l l l l l l l 9 I I I I I I I I I I I I I I I I I I I I I a.35 cfs I I I 1 1 I- - -1 1 i 1 I -Type fill-24 hr - i- T-11- -i - 1I - 1 -i - i 1007Yr-lRllainfal1�8.-080'. 7 Run6ff Mee=0.780 ad. 1 1 1 1 1 1 1 1 6 1 1 1 1 I I I I Runoff lVolume=0.438 of 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -RuinOff 11D4pth>6.1/ 41 0 ff 4 1 — I— -r —I— 1- —1 — I— rt — 1— -r —1 —1 — r -t — I— -r —1—T-c:7.10 1tri 1 1 1 1 1 1 1 + t + + 1 C 83 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -4-1—-4--1-4--1-1—-4—I—+-1 1 1 1 1—1-4—I- 2 1 1 1 1 1 1 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 (POST) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 29 Summary for Subcatchment 2S: Post Area 1-4 (Onsite, Detained) Runoff = 12.90 cfs @ 11.96 hrs, Volume= 0.700 af, Depth> 7.71" 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 100-Yr Rainfall=8.80" Area (ac) CN Description 1.090 91 VRRM SPREADSHEET D.A. B 1.090 100.00% Pervious 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 14 ■Runoff 13 1 _1DO cfs -4- 1- 4 -1 - -1 - - 1- 4 - 1 T I -1 - 4- -1 - -4- ITy�peal4-24-h 12 100T I r h/ IN I�w 61- Rpinf011.0 1 10 -1-T-1-T_-1-F_ 7 1 -�unbffAi=e-6=1-.09-0aid -4 1 4 I � 1 4 1 1 k--4 I 4- I t- 1 � 9 1 1 1 1 1Runoffl Volumle�0.700 of 0 1 1 1 1 1 1 -1- --1- -1--1 nQ#IIDgptb�71`l-1' � T 1- r 7 1- 7 o ' -4 -I- -I- 4- -1- -4 -1- 4 -I I-T 1 - -4 -I- IC� i� LL 6 1 1 11 1 1 1 1 1 1 1 1 1 1 1 _1_/1 1 1 1 1 1 1 r`J►1�1 �� 1 5 - 1 7 1 T_ 1 F- 1 7 1 - r I r-_t I _r I r- I r- 4 - 1 4 1 1- 1 1 4 1 - �_ 1 -1 1 1 4- 1 � 3 2 - -1- 7 1 1 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) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 17S: Post Area 1-5 (Onsite, Undetained) Runoff = 10.63 cfs @ 11.96 hrs, Volume= 0.560 af, Depth> 7.22" 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 100-Yr Rainfall=8.80" Area (ac) CN Description 0.930 87 VRRM SPREADSHEET D.A. D 0.930 100.00% Pervious 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) -A I 1 1 L 1 11 I I I I I I 10 9 8 - F rt 1 L 1 i 7 I I I I 1 1 6 1 1 1 1 1 o 1+11�— LL 5 7 T- 3 2 Hydrograph 1I -L1 L1L1L 10.63 cfs I I I I TyrpeA kM--hr - 11 I00jY j R1pi 1nMH78 06. 'Runbff Mec1=0:9-30 ad I I I I I I I I 1RunoffrVokff e=;6.560-af 1 -4 I Tc:l--610 -'rri h I I I I I / ham Imp I� I I �J►I�I�pII 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) Type // 24-hr 100-YrRainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCAD® 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 31 Summary for Pond 19P: SWM 3 [93] Warning: Storage range exceeded by 0.21' [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.870 ac, 0.00% Impervious, Inflow Depth > 7.30" for 100-Yr event Inflow = 21.05 cfs @ 11.97 hrs, Volume= 1.138 of Outflow = 21.60 cfs @ 11.96 hrs, Volume= 1.138 af, Atten= 0%, Lag= 0.0 min Primary = 21.60 cfs @ 11.96 hrs, Volume= 1.138 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 427.81' @ 11.96 hrs Surf.Area= 0.000 ac Storage= 0.081 of Plug -Flow detention time=4.3 min calculated for 1.138 of (100% of inflow) Center -of -Mass det. time= 4.2 min ( 779.0 - 774.8 ) Volume Invert Avail.Storage Storage Description #1 422.00' 0.081 of 60.0" Round CMP Round 60" L= 180.0' S= 0.0033 T 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' 7.5" 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=20.86 cfs @ 11.96 hrs HW=427.75' (Free Discharge) 1=Culvert (Passes 11.92 cfs of 15.02 cfs potential flow) L2=Orifice/Grate (Orifice Controls 3.45 cfs @ 11.23 fps) 4=Sharp-Crested Rectangular Weir(Weir Controls 8.47 cfs @ 3.35 fps) 3=Orifice/Grate (Orifice Controls 8.95 cfs @ 7.16 fps) Keswick Hall_Spa_Analysis Points 1 (POST) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 32 Pond 19P: SWM 3 Hydrograph fi — I — t —1 —1— fi — I — 1- -t —I— T I I i I— t- —1— t —1— 7 7 —I— '_T T1 F 7 1 1 1 24 i — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 23 i 1 1 L I 1 1 I L L A I L/�-1 I _L I L -1 1 22 - —I— +- —1 — 1— 4 — I — { _4 21.60dr Anfla1w+Aream r.1�'ac 21 20 X 7 I T 7 I L _I I- 7 I T-1 F 7 1 T 1 1 441tprageF0,06taf 17 7-i-r-11-i-rt-11-r7-11 16 ' ' 1 1 15 i — — — — — — — — — — — — — — — — — — — H 14 i -4 I 1 I 7 I ! I T I v 13 i rt — I — t —1 —I— rt — I — 1- rt —I - I— rt —I— fi —I— rt —I— - —1- 3 12 ' I I I c11 i — — — — — — — — — — — — — - — — — — — — — — — — — — — — — " 10 i 1 _1_ L —1 _1— 1 _1_ L - _I _ I— - _1_ L J _I— 1 —1_ L J _I- 9 i _ I t 1 1 7 I i I I T I t 1 1 8 7 —1— T —1 —1— 7 —1— L 7 —I —1— 7 —1— 7 7 —1— 6 —I— 1 —I —I— 1 —I— 1 —I — 1 —I— —I —I— —I— —I- 5 i -4 I +- 1 1 7 I -4 I 4 I T� 1 4 1 I 4—I- 3 i 1 1 - 2 1 1 0 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) IN Inflow 11 ■ Primary Keswick Hall_Spa_Analysis Points 1 (POST) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 1/6/2020 HydroCADO 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC Page 33 Summary for Link 18L: Areas Combined Inflow Area = 2.800 ac, 0.00% Impervious, Inflow Depth > 7.28" for 100-Yr event Inflow = 32.23 cfs @ 11.96 hrs, Volume= 1.698 of Primary = 32.23 cfs @ 11.96 hrs, Volume= 1.698 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 Hydrograph rt T- 1 1 rt L -1rt 1 rt fi- 1 rt 1 r-- 1 36 / rt — 1— — 34 / -1- r � 32.cfs w"23 1 fie� � 18 —InfloZ.00-az 32 fi 1 1 fi 1 1 1 1 1 t 1 r 30 28 26 24 22 -4 1 1 4 4 20 4 3 18I— LL 16 14 i 1 I L 1 1 1 1 L L 1 1 L 11 I L L 12 10 II 8 6 4 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) F Inflow ❑ Primary CMBMNMII 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: "Tomorrow's Natural Resources Tod y" 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 § 62.1-44.15:35. 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. Re .& Scott A. Reed Vice President Chesapeake Bay Nutrient Land Trust, LLC. 9 5735 S. Laburnum Avenue 9 Richmand,VA 23231 9 P: 804.222.5114 ■ www.cbnit.com