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HomeMy WebLinkAboutWPO201800078 Calculations 2018-10-22 Keswick Hall Spa WPO 2018 COUNTY OF ALBEMARLE, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE OCTOBER 22, 2018 � •.•fs • • • TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 111 W. High Street Charlottesville, VA 22902 434.327.1688 (/‘‘41.21W4%, U CRAIG W.J.KOTARSKI Lic.No. 0402048507 010/22/18 SWONAL APPROVED by the Albemarle County Community Deielopm nt Department Date � Z t'� 11 - -File P15—/e 63' v0.05 Table of Contents Section Title 1 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. Limits of clearing and grading area is 2.67 acres. Water Quality Compliance: The disturbed area of 2.27 acres was used for the water quality analysis. In the proposed condition there will be 0.87 acres of managed turf, 1.35 acres of impervious cover and 0.05 acres of forest. Phosphorus removal will be achieved through the purchase of nutrient credits. Water Quantity Compliance: Stormwater Quantity requirements for analysis point 1 will utilize a series of CMP detention systems 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. Y FORM LD 204 STORMWATER INLET COMPUTATIONS SHEET 1 OF 1 ROUTE Club Drive PROJECT Keswick Hall Spa DESIGNER: CG DATE 10/22/2018 CHECKED: UNITS ENGLISH INLET Sag Inlets Only v z 'IT oc 3 a a t- a _ C. a z f. c o oc ❑ C z p � m t � m a = o o - e � U aU cc . 2 i3 'd �� a.a. SS U m �� � � a � , � � p2 4 < U s .1vi Li < 3 3 a W. - d XF, aof 2 .v o0 :al - Z F. 0 y t7 O 1L' V ...114 tal 4. -0 a ❑ S n o Al > - - 114 DI-3C 6.000 0 4 0 0 Back/Lt. 0.000'RIGH' 0.200 0.74 0.148 Ahead/Rt. 0.148 4 0.592 0 0.0010 0.0229 6.992 2.000 0.286 0.0833 3.6376 3.45 Ahead/Rt. 0.592 0.0010 6 0.592 1.074 0.183 0.0153 12 3.074 3.907 Weir Flow 116 DI-38 4.000 0.230 0.68 0.1564 0.000'RIGHT 0.156 4 0.624 0 0.624 0.0100 0.0227 3.474 2.000 0.5757 0.0833 3.6696 0.970 3.45 0.1439 0.1623 4.574 4.000 0.875 0.976 0.609 0.015 2.401 122 DI-9 2.000 0.430 0.55 0.2365 Back/Lt. 0.000'RIGHT 0.237 4 0.948 0 0.001 0.0390 6.456 2.000 0.3098 0.0833 2.1359 3.06 Back/Lt. 0 4 0 0 Ahead/Rt. 0.948 0.001 2.000 2 0.948 1.981 0.312 -900 4.233 Weir Flow 126 D1-9 2.000 0.420 0.55 0.2 31 Back/Lt. 0.000'RIGHT 0.231 4 0.924 0 0.001 0.0208 10.143 2.000 0.1972 0.0300 1.4423 2.22 Back/Lt. 0 4 0 0 Ahead/Rt. 0.924 0.001 2.000 2 0 024 4.051 0.166 6.771 16.231 T>8.0 ft 132 DI-9 1.250 0.240 0.57 0.1368 0.000'RIGHT 0.137 4 0.548 0 0.548 0.0100 0.0460 2.550 2.000 0.7843 0.0833 1.8109 0.992 2.90 0.1206 0.1657 4.278 1.250 0.292 0.993 0.544 0.004 2.303 134 DI-9 1.250 0.070 0.61 0.0427 0.000'RIGHT 0.043 4 0.172 0 0.172 0.0100 0.0430 1.495 2.000 1.3378 0.0833 1.9372 1.000 2.97 0.1236 0.1666 2.620 1.250 0.477 1.000 0.172 0.000 1.494 136 DI-9 1.000 0.010 0.90 0.009 Back/Lt. 0.000'RIGHT 0.009 4 0.036 0 0.001 0.0208 3.041 8.000 2.6307 0.0209 1.0048 2 01 Back/Lt. 0 4 0 0 Ahead/Rt. 0.036 0.001 1.000 1 0.036 0.293 0.166 2.544 1.175 Weir Flow INLETSOFT BY ENSOFTEC DATE: 10/22/2018 LD-229 PROJECT: Keswick Hall Spa Designed by: CG STORM SEWER DESIGN COMPUTATIONS LOCATION: Charlottesville COUNTY: Charlottesville Checked by: STORM FREQUENCY 10 NOAA STATION: UNITS ENGLISH DRAIN. RUNOFF CA TOTAL RAIN RUNOFF INVERT ELEVATIONS LENGTH SLOPE SIZE SHAPE'Number Capacity Friction NORMAL FLOW FLOW PIPE FROM POINT TO POINT AREA COEFF. INCRE- ACCUM- INLET FALL Lateral Total Q UPPER LOWER of Pipe (Dia.Or of Pipes Slope Depth of Area of Hrn Vn En TIME NO. REFERENCE STA. REFERENCE STA. "A" "C" MENT ULATED TIME END END Span/Rise) Flow,do Flow,An REMARKS Acre Minutes In/Hr CFS CFS Ft. Ft./Ft. In. CFS Ft./Ft. Ft. SqFt Ft. Ft/Sec Ft. Sec. (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (111 (12) (13) (14) (15) _ (16) (17) (18) 101 102 100 0.00 0.00 0.00 5.40 6.41 0.00 9.83 415.88 415.01 58.07 0.01498 18 Circular 1 13.93 0.00780 0.93 1.15 0.42 8.54 2.06 6.80 103 104 102 0.00 0.00 0.00 5.28 6.45 0.00 9.83 416.89 415.98 60.45 0.01505 18 Circular_ 1 13.96 0.00780 0.93 1.15 0.42 8.56 2.07 7.06 105 106 104 0.00 0.00 0.00 5.20 6.48 0.00 9.83 421.07 416.99 74.14 0.05503 18 Circular_ I 26.70 0.00780 0.63 0.70 0.33 13.96 3.65 5.31 107 SWM 3 Out 106 0.00 0.00 0.00 5.00 0.00 9.83 421.50 421.17 65.04 0.00507 18 Circular 1 8.10 0.00780 1.50 1.77 0.38 5.56 1.98 11.69 Pressure Flow 109 SWM 4 Out 104 0.00 0.00 0.00 5.00 0.00 0.00 2.93 424.00 417.76 75.58 0.08256 15 Circular 1 20.11 _0.00180 0.32 0.25 0.19 `11.69 2.44 6.47 111 112 SWM 4 In 0.00 0.00 0.15 5.12 6.50 0.00 0.97 425.66 425.40 25.93 0.01003 12 Circular 1 3.87 0.00070 0.34 0.24 0.19 4.10 0.60 6.33 113 114 112 0.20 0.74 0.15 0.15 5.00 6.54 0.00 0.97 426.05 425.76 29.00 0.01000 12 Circular 1 3.86 _0.00070 0.34 0.24 0.19 4.09 0.60 7.09 115 116 SWM 4 In 0.23 0.68 0.16 0.16 5.00 6.54 0.00 1.02 426.38 426.24 27.00 0.00519 12 Circular I 2.78 0.00070 0.42 0.31 0.22 3.27 0.59 8.26 121 122 SWM 3 In 0.43 0.55 0.24 0.53 5.11 6.51 0.00 3.46 424.60 424.39 41.30 0.00508 15 Circular 1 4.99 0.00250 0.77 0.79 0.35 4.39 1.07 9.41 - 123 124 122 0.07 0.90 0.06 0.06 5.00 6.54 0.00 0.41 425.57 425.35 21.40 0.01028 6 Circular 1 0.62 0.00480 0.30 0.12 0.14 3.37 0.48 6.35 125 126 122 0.42 0.55 0.23 0.23 5.00 5.04 0.00 1.17 424.76 424.70 12.73 0.00471 15 Circular 1 4.43 0.00030 0.44 0.38 0.24 3.05 0.58 4.18 131 132 SWM 3 In 0.24 0.57 0.14 0.19 5.48 6.39 0.00 1.21 424.92 424.58 33.51 0.01015 12 Circular 1 3.89 0.00100 0.38 0.28 0.21 4.38 0.68 7.66 133 134 132 0.07 0.61 0.04 0.05 5.24 6.47 0.00 0.34 425.46 425.02 44.29 0.00993 12 Circular 1 3.85 0.00010 0.20 0.11 0.12 3.02 0.34 14.66 135 136 134 0.01 0.90 0.01 0.01 5.00 6.54 0.00 0.06 ( 425.82 425.56 25.83 0.01007 12 Circular I 1 3.87 0.00000 0.09 0.03 0.06 1.82 0.14 14.21 r LD-347 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INVERT 1 DEPTH OUTLET DIA. DESIGN LENGTH FRICTION 'FRICTION JUNCTION LOSS Adj.Ht Inlet Inlet Top of MH INLET STA. EL. OF FLOW WATER PIPE DISCH. PIPE SLOPE,Sfo LOSS Contr. Hi(Expn) SKEW Bend Sum SURFACE 1.3 Shaping? 0.5 FINAL Water Top of Inlet Adjustment? OR OUTFLOW OUTFLOW SURFACE Do Qo Lo (FT/FT) Hf Vo Ho Vi Vi*2/2g 0.35*MAX. Angle K H HL FLOW Ht Ht H Surface Elev. JUNCTION PIPE PIPE ELEV. (In/mm) (CFS/CMS) (Ft/M) (M/M) , (Ft/M) (Ft/M) (Vi2/2 g) (Ft/M) (Ft/M) (Ft/M) Y/N (Ft/M) (Ft/M) Elevation APPROX. (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) _ (16) (17) (18) (19) 100 415.000 102 415.010 1.50 416.210 18 9.830 58.07 0.00780 0.453 8.543 0.283 8.558 1.137 0.398 0.0 0.00 0.000 0.681 0.000 0.681 YES 0.341 0.794 417.004 419.630 O.K. 104 415.980 1.50 417.180 18 9.830 60.45 0.00780 0.472 8.558 0.284 13.956 3.024 1.059 0.0 0.00 0.000 1.343 0.000 1.343 YES 0.671 1.143 418.323 425.960 O.K. 106 416.990 1.50 418.323 18 9.830 74.14 0.00780 0.578 13.956 0.756 5.563 0.481 0.168 0.0 0.00 0.000 0.924 0.000 0.924 YES 0.462 1.040 421.700 429.200 O.K. SWM 3 Out 421.170 1.50 422.670 18 9.830 65.04 0.00780 0.507 5.563 0.120 0.000 0.000 0.000 0.0 0.00 0.000 0.120 0.000 0.120 YES 0.060 0.567 423.237 426.000 O.K. SWM 4 Out 417.760 1.25 418.760 15 2.930 75.58 0.00183 0.138 11.688 0.530 0.000 0.000 0.000 0.0 0.00 0.000 0.530 0.000 0.530 YES 0.265 0.404 424.322 428.000 O.K. LD-347 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INVERT DEPTH OUTLET DIA. DESIGN LENGTH FRICTION FRICTION JUNCTION LOSS Adj.Ht Inlet Inlet Top of MH INLET STA. EL. OF FLOW WATER I PIPE DISCH. PIPE SLOPE,Sfo LOSS Contr. Hi(Expn) SKEW Bend Sum SURFACE 1.3 Shaping? 0.5 FINAL Water Top of Inlet Adjustment? OR OUTFLOW OUTFLOW SURFACE Do Qo Lo (FT/FT) Hf Vo Ho Vi Vi'2/2g 0.35*MAX. Angle K H HL FLOW Ht Ht H Surface Elev. JUNCTION PIPE PIPE ELEV. (In/mm) (CFS/CMS) (Ft/M) (M/M) (Ft/M) (Ft/M) (Vi2/2g) (Ft/M) (FUM) (FUM) Y/N (FUM) (FUM) Elevation APPROX. (1) (2) (3) . (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (16) , (17) (18) (19) SWM 3 In 426.000 132 424.580 1.00 426.000 12 1.213 33.51 0.00103 0.035 4.376 0.074 3.020 0.142 0.050 0.0 0.00 0.000 0.124 0.875 0.161 YES 0.081 0.115 426.115 429.750 O.K. 134 425.020 1.00 426.115 12 0.338 44.29 0.00008 0.004 3.020 0.035 1.817 0.051 0.018 0.0 0.00 0.000 0.053 0.278 0.069 YES 0.035 0.038 426.153 430.900 O.K. 136 425.560 1.00 426.360 12 0.059 25.83 0.00000 0.000 1.817 0.013 0.000 0.000 0.000 0.0 0.00 0.000 0.013 0.059 0.017 YES 0.008 0.008 426.368 429.820 O.K. 122 424.390 1.25 426.000 15 3.457 41.30 0.00255 0.105 4.389 0.075 3.046 0.144 0.050 0.0 0.00 0.000 0.125 1.542 0.163 YES 0.081 0.187 426.187 427.550 O.K. 124 425.350 0.50 426.187 6 0.412 21.40 0.00480 0.103 3.368 0.044 0.000 0.000 0.000 0.0 0.00 0.000 0.044 0.000 0.044 YES 0.022 0.125 426.312 429.300 O.K. 126 424.700 1.25 426.187 15 1.165 12.73 0.00034 0.004 3.046 0.036 0.000 0.000 0.000 0.0 0.00 0.000 0.036 1.165 0.047 YES 0.023 0.028 426.214 427.550 O.K. LD-347 PROJECT: Keswick Hall Spa DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INVERT DEPTH OUTLET DIA. DESIGN LENGTH FRICTION FRICTION JUNCTION LOSS Adj.Ht Inlet Inlet Top of MH INLET STA. EL. OF FLOW WATER PIPE DISCH. PIPE SLOPE,Sfo LOSS Contr. Hi(Expn) SKEW Bend Sum SURFACE 1.3 Shaping? 0.5 FINAL Water Top of Inlet Adjustment? OR OUTFLOW OUTFLOW SURFACE Do Qo Lo (FT/FT) Hf Vo Ho Vi Vi*2/2g 0.35*MAX. Angle K H HL FLOW Ht Ht H Surface Elev. JUNCTION PIPE PIPE ELEV. (In/mm) (CFS/CMS) (FUM) (M/M) (FUM) (Ft/M) (Vi2/2g) (FUM) (FUM) (FUM) Y/N FUM( ) (FUM) Elevation APPROX. (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) , (11) (12) , (13) (14) (15) (16) (16) (17) (18) (19) SWM 4 In 428.000 112 425.400 1.00 428.000 12 0.968 25.93 0.00066 0.017 4.096 0.065 4.091 0.260 0.091 0.0 0.00 0.000 0.156 0.000 0.156 YES 0.078 0.095 428.095 430.800 O.K. 114 425.760 1.00 428.095 12 0.968 29.00 0.00066 0.019 4.091 0.065 0.000 0.000 0.000 0.0 0.00 0.000 0.065 0.968 0.084 YES 0.042 0.061 428.156 430.800 O.K. 116 426.240 1.00 428.000 12 1.021 27.00 0.00073 0.020 3.270 0.042 0.000 0.000 0.000 0.0 0.00 0.000 0.042 1.021 0.054 YES 0.027 0.047 428.047 430.800 O.K. 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: 2.27 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 0.92 0.92 41 Managed Turf(acres) 0.00 0.00 0.00 0.60 0.60 26 Impervious Cover(acres) 0.00 0.00 0.00 0.75 0.75 33 2.27 100 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 0.05 0.05 2 Managed Turf(acres) 0.00 0.00 0.00 0.87 0.87 38 Impervious Cover(acres) 0.00 0.00 0.00 1.35 1.35 59 •Forest/Open Space areas must be protected in accordance with the Virginia Runoff Reduction Method 2.27 100 Site Tv and Land Cover Nutrient Loads Pre- Final Post-Development Post- Post- Adjusted Pre- ReDevelopment Final Post-Development Post-ReDevelopment TP (Post-ReDevelopment Development TP Load per acre Load per acre &New Impervious) ReDevelopment ReDevelopment TP Load per acre (New Impervious) (Ib/acre/yr) (Ib/acre/yr) (Ib/acre/yr) Site Rv 0.66 0.56 0.95 0.53 1.20 1.51 1.27 Treatment Volume(ft3) 5,454 3,385 2,069 3,189 TP Load(Ib/yr) 3.43 2.13 1.30 2.00 Total TP Load Reduction Required(Ib/yr) 1.58 0.52 1.05 Final Post-Development Load Pre- (Post-ReDevelopment&New Impervious) ReDevelopment TN Load(Ib/yr) 24.51 14.82 Site Compliance Summary Maximum%Reduction Required Below 20% Pre-ReDevelopment Load Summary Print Virginia Runoff Reduction Method Worksheet Total Runoff Volume Reduction(ft') 919 Total TP Load Reduction Achieved(Ib/yr) 0.72 • Total TN Load Reduction Achieved(Ib/yr) 5.30 Remaining Post Development TP Load (lb/yr) 2.71 Remaining TP Load Reduction(Ib/yr) 0.86 Required 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) 0.17 0.09 0.00 0.00 0.00 0.26 Impervious Cover(acres) 0.44 0.33 0.00 0.00 0.00 0.77 Total Area(acres) 0.61 0.42 0.00 0.00 0.00 1.03 Drainage Area Compliance Summary D.A.A D.A.B D.A.C D.A.D D.A.E Total TP Load Reduced(Ib/yr) 0.44 0.28 0.00 0.00 0.00 0.72 TN Load Reduced(Ib/yr) 3.30 2.00 0.00 0.00 0.00 5.30 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 0.17 0.17 28 Impervious Cover(acres) 0.00 0.00 0.00 0.44 0.44 72 0.61 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit ; Upstream (acres) Area(acres) Volume(ft) Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed Total Impervious Cover Treated(acres) 0.25 Total Turf Area Treated(acres) 0.00 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. (lb/yr) 0.44 Total TN Load Reduction Achieved in D.A. (Ib/yr) 3.30 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 0.09 0.09 21 Impervious Cover(acres) 0.00 0.00 0.00 0.33 0.33 79 0.42 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream (acres) Area(acres) Volume(fta► Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed Total Impervious Cover Treated(acres) 0.22 Total Turf Area Treated(acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.28 Total TN Load Reduction Achieved in D.A. (Ib/yr) 2.00 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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream Volume(ft3) 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 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (Ib/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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream (acres) Area(acres) Volume(ft;) Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated(acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream (acres) Area(acres) Volume(ft3) Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed 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. (Ib/yr( 0.00 Total TN Load Reduction Achieved in D.A. (Ib/yr) 0.00 Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event(in) 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 93 94 0 0 0 RR(k'( 578 341 0 0 0 RV wo RR(ws-in) 2.18 2.27 0.00 0.00 0.00 1-year return period RV w RR(ws-in) 1.92 2.05 0.00 0.00 0.00 CN adjusted 90 91 0 0 0 RV wo RR(ws-in) 2.77 2.87 0.00 0.00 0.00 2-year return period RV w RR(ws-in) 2.51 2.65 0.00 0.00 0.00 CN adjusted 90 92 0 0 0 RV wo RR(ws-in) 4.54 4.65 0.00 0.00 0.00 10-year return period RV w RR(ws-in) 4.28 4.43 0.00 0.00 0.00 CN adjusted 91 92 0 0 0 Summary Print 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: 2.27 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 0.92 0.92 41 Managed Turf(acres) 0.00 0.00 0.00 0.60 0.60 26 Impervious Cover(acres) 0.00 0.00 0.00 0.75 0.75 33 2.27 100 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 0.05 0.05 2 Managed Turf(acres) 0.00 0.00 0.00 0.87 0.87 38 Impervious Cover(acres) 0.00 0.00 0.00 1.35 1.35 59 •Forest/Open Space areas must be protected in accordance with the Virginia Runoff Reduction Method 2.27 100 Site Tv and Land Cover Nutrient Loads Pre- Final Post-Development Post Post- Adjusted Pre- ReDevelopment Final Post-Development Post-ReDevelopment TP (Post-ReDevelopment ReDevelopment Development ReDevelopment TP Load per acre TP Load per acre Load per acre &New Impervious) (New Impervious) (Ib/acre/yr) (Ib/acre/yr) (Ib/acre/yr) Site Rv 0.66 0.56 0.95 0.53 1.20 1.51 1.27 Treatment Volume(ft3) 5,454 3,385 2,069 3,189 TP Load(lb/yr) 3.43 2.13 1.30 2.00 Total TP Load Reduction Required(lb/yr) 1.58 0.52 1.05 Final Post-Development Load Pre- (Post-ReDevelopment&New Impervious) ReDevelopment TN Load(Ib/yr) 24.51 14.82 Site Compliance Summary Maximum%Reduction Required Below 20% Pre-ReDevelopment Load Summary Print Virginia Runoff Reduction Method Worksheet Total Runoff Volume Reduction(ft3) 919 Total TP Load Reduction Achieved(Ib/yr) 0.72 Total TN Load Reduction Achieved(Ib/yr) 5.30 Remaining Post Development TP Load (lb/yr) 2.71 Remaining TP Load Reduction(Ib/yr) 0.86 Required 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) 0.17 0.09 0.00 0.00 0.00 0.26 Impervious Cover(acres) 0.44 0.33 0.00 0.00 0.00 0.77 Total Area(acres) 0.61 0.42 0.00 0.00 0.00 1.03 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) 0.44 0.28 0.00 0.00 0.00 0.72 TN Load Reduced(Ib/yr) 3.30 2.00 0.00 0.00 0.00 5.30 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 0.17 0.17 28 Impervious Cover(acres) 0.00 0.00 0.00 0.44 0.44 72 0.61 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream Volume(ft3) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed (acres) Area(acres) Practices(Ibs) Total Impervious Cover Treated(acres) 0.25 Total Turf Area Treated(acres) 0.00 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.44 Total TN Load Reduction Achieved in D.A. (Ib/yr) 3.30 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 0.09 0.09 21 Impervious Cover(acres) 0.00 0.00 0.00 0.33 0.33 79 0.42 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream (acres) Area(acres) ' Volume(ftn) Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed Total Impervious Cover Treated(acres) 0.22 Total Turf Area Treated(acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.28 Total TN Load Reduction Achieved in D.A. (Ib/yr) 2.00 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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit n ( )Upstream to Practice Ibs Ib/yr) (Ib/yr) to be Employed (acres) Area(acres) Volume(ft► 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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream (acres) Area(acres) Volume(ft;) Practices(Ibs) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated(acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (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 TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit Upstream Volume(ft3) 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 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (Ib/yr) 0.00 Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event(in) 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 93 94 0 0 0 RR(fta) 578 341 0 0 0 RV wo RR(ws-in) 2.18 2.27 0.00 0.00 0.00 1-year return period RV w RR(ws-in) 1.92 2.05 0.00 0.00 0.00 CN adjusted 90 91 0 0 0 RV wo RR(ws-in) 2.77 2.87 0.00 0.00 0.00 2-year return period RV w RR(ws-in) 2.51 2.65 0.00 0.00 0.00 CN adjusted 90 92 0 0 0 RV wo RR(ws-in) 4.54 4.65 0.00 0.00 0.00 10-year return period RV w RR(ws-in) 4.28 4.43 0.00 0.00 0.00 CN adjusted 91 92 0 0 0 Summary Print 4S 13L Pre Area 1 -1 (Offsite) Areas Combined (1 -1 + 1 -2) 12S Pre Area 1 -2 (Onsite) SubCat Reach 'on• Routing Diagram for Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group, Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.890 83 VRRM SPREADSHEET D.A. A (4S) 2.310 85 VRRM SPREADSHEET D.A. B (12S) 3.200 84 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 3.200 Other 4S, 12S 3.200 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC 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 0.890 0.890 VRRM SPREADSHEET D.A.A 4S 0.000 0.000 0.000 0.000 2.310 2.310 VRRM SPREADSHEET D.A. B 12 S 0.000 0.000 0.000 0.000 3.200 3.200 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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=0.890 ac 0.00% Impervious Runoff Depth>1.38" Tc=7.0 min CN=83 Runoff=2.08 cfs 0.102 af Subcatchment12S: Pre Area 1-2 (Onsite) Runoff Area=2.310 ac 0.00% Impervious Runoff Depth>1.52" Tc=7.0 min CN=85 Runoff=5.93 cfs 0.292 af Link 13L:Areas Combined(1-1 + 1-2) Inflow=8.01 cfs 0.395 af Primary=8.01 cfs 0.395 af Total Runoff Area= 3.200 ac Runoff Volume = 0.395 af Average Runoff Depth = 1.48" 100.00% Pervious = 3.200 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 2.08 cfs @ 11.99 hrs, Volume= 0.102 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% 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 ❑Runoff` 12.08 cfs I 2 7 Type II 24-hr 1-YR Rainfall=2.92" Runoff Area=0.890 ac Runoff Volume=0.102 af Runoff Depth>1 .38" Tc=7.0 min CN=83 4I 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) Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 5.93 cfs @ 11.98 hrs, Volume= 0.292 af, Depth> 1.52" 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 * 2.310 85 VRRM SPREADSHEET D.A. B 2.310 100.00% 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 ❑Runoff 6 Iss�l Type II 24-hr 1-YR Rainfall=2.92" 5 Runoff Area=2.310 ac Runoff Volume=0.292 of 4 i Runoff Depth>1 .52" 3 Tc=7.0 m i n CN=85 2 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 II 24-hr 1-YR Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 3.200 ac, 0.00% Impervious, Inflow Depth > 1.48" for 1-YR event Inflow = 8.01 cfs @ 11.98 hrs, Volume= 0.395 af Primary = 8.01 cfs @ 11.98 hrs, Volume= 0.395 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 •Inflow II 8.ol cfs •Primary 8� I B 01 cfs` Inflow Area=3.200 ac 7 6 F. 5 0 4 u. 3 2 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) Keswick Hall_Spa_Analysis Points 1 (PRE) Type ll 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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=0.890 ac 0.00% Impervious Runoff Depth>1.89" Tc=7.0 min CN=83 Runoff=2.84 cfs 0.140 af Subcatchment12S: Pre Area 1-2(Onsite) Runoff Area=2.310 ac 0.00% Impervious Runoff Depth>2.05" Tc=7.0 min CN=85 Runoff=7.93 cfs 0.394 af Link 13L:AreasCombined(1-1 + 1-2) Inflow=10.76 cfs 0.534 af Primary=10.76 cfs 0.534 af Total Runoff Area = 3.200 ac Runoff Volume= 0.534 af Average Runoff Depth = 2.00" 100.00% Pervious = 3.200 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 2.84 cfs @ 11.98 hrs, Volume= 0.140 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 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% 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 / ❑Runoff` 3 I284 cfs I Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=0.890 ac 2 K Runoff Volume=0.140 of Runoff Depth>1 .89" Tc=7.0 min / 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) Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 7.93 cfs @ 11.98 hrs, Volume= 0.394 af, Depth> 2.05" 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 * 2.310 85 VRRM SPREADSHEET D.A. B 2.310 100.00% 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 / ❑Runoff 8 l�s�l Type II 24-hr 7 2-YR Rainfall=3.54" 6- Runoff Area=2.310 ac a/ Runoff Volume=0.394 of 5- Runoff Depth>2.05" 4- Tc=7.0 min 3 CN=85 2 / zoe 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 II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 12 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 3.200 ac, 0.00% Impervious, Inflow Depth > 2.00" for 2-YR event Inflow = 10.76 cfs @ 11.98 hrs, Volume= 0.534 af Primary = 10.76 cfs @ 11.98 hrs, Volume= 0.534 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 12-/ ■Inflow 1 10.76 cfs 1 ■Primary 11 I1076cfs Inflow Area=3.200 ac 10- 9- 8- N 7_ U 67 0 U. 5- 4- 3- 2- 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) Keswick Hall_Spa_Analysis Points 1 (PRE) Type ll 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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=0.890 ac 0.00% Impervious Runoff Depth>3.49" Tc=7.0 min CN=83 Runoff=5.12 cfs 0.259 af Subcatchment12S: Pre Area 1-2(Onsite) Runoff Area=2.310 ac 0.00% Impervious Runoff Depth>3.69" Tc=7.0 min CN=85 Runoff=13.90 cfs 0.710 af Link 13L:AreasCombined(1-1 + 1-2) Inflow=19.02 cfs 0.969 af Primary=19.02 cfs 0.969 af Total Runoff Area = 3.200 ac Runoff Volume = 0.969 af Average Runoff Depth = 3.63" 100.00% Pervious = 3.200 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 4S: Pre Area 1-1 (Offsite) Runoff = 5.12 cfs @ 11.98 hrs, Volume= 0.259 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 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% 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 / ❑Runoff 1512crs 5 Type II 24-hr 10-YR Rainfall=5.35" 4 ( Runoff Area=0.890 ac ^/ Runoff Volume=0.259 af 3 Runoff Depth>3.49" Tc=7.0 min 2 / CN=83 r w 3 ,//// 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 II 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pane 15 Summary for Subcatchment 12S: Pre Area 1-2 (Onsite) Runoff = 13.90 cfs @ 11.98 hrs, Volume= 0.710 af, Depth> 3.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.35" Area (ac) CN Description * 2.310 85 VRRM SPREADSHEET D.A. B 2.310 100.00% 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 15-/ ❑Runoff` 14- I139�I Type II 24-hr 13- 12_ 10-YR Rainfall=5.35" Runoff Area=2.310 ac ° Runoff Volume=0.710 af 9- 2. 8_ Runoff Depth>3.69" ° 7- Tc=7.0 min 6= ,l CN=85 2= *r./, 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) Keswick Hall_Spa_Analysis Points 1 (PRE) Type II 24-hr 10-YR Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 16 Summary for Link 13L: Areas Combined (1-1 + 1-2) Inflow Area = 3.200 ac, 0.00% Impervious, Inflow Depth > 3.63" for 10-YR event Inflow = 19.02 cfs @ 11.98 hrs, Volume= 0.969 af Primary = 19.02 cfs @ 11.98 hrs, Volume= 0.969 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 21 Inflow I 19.02cn I ❑Primary 20' I1902d; Inflow Area=3.200 ac 19= 18i 17= 16: 14= 13' n 12- 11', e 10.. LL 9- 8: 7. 65 } 5: �! 4. 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) • Post Area 1-5 (Offsite, detained) 19P SWM 3 18L Post Area 1-6 (Onsite, Post Area 1-8 (Onsite, Detained) Areas Combined Undetained) 20P 16S SWM 4 Post Area 1-7 (Onsite, Detained) 4ubca) Reach 'on. Routing Diagram for Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Prepared by Timmons Group, Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC • Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.890 83 VRRM SPREADSHEET D.A. A (1S) 0.610 91 VRRM SPREADSHEET D.A. B (2S) 0.420 91 VRRM SPREADSHEET D.A. C (16S) 1.240 88 VRRM SPREADSHEET D.A. D (17S) 3.160 88 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 3.160 Other 1 S, 2S, 16S, 17S 3.160 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC 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 0.890 0.890 VRRM SPREADSHEET D.A. A 1S 0.000 0.000 0.000 0.000 0.610 0.610 VRRM SPREADSHEET D.A. B 2S 0.000 0.000 0.000 0.000 0.420 0.420 VRRM SPREADSHEET D.A. C 16 S 0.000 0.000 0.000 0.000 1.240 1.240 VRRM SPREADSHEET D.A. D 17 S 0.000 0.000 0.000 0.000 3.160 3.160 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 421.50 419.50 100.0 0.0200 0.013 18.0 0.0 0.0 2 20P 424.00 422.00 100.0 0.0200 0.013 15.0 0.0 0.0 Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©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 SubcatchmentlS: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>1.38" Tc=7.0 min CN=83 Runoff=2.08 cfs 0.102 af Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>1.99" Tc=6.0 min CN=91 Runoff=2.03 cfs 0.101 af Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>1.99" Tc=6.0 min CN=91 Runoff=1.40 cfs 0.070 af Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>1.75" Tc=6.0 min CN=88 Runoff=3.68 cfs 0.180 af Pond 19P: SWM 3 Peak Elev=424.44' Storage=0.039 af Inflow=4.10 cfs 0.204 af Outflow=1.98 cfs 0.203 af Pond 20P: SWM 4 Peak Elev=425.79' Storage=0.014 af Inflow=1.40 cfs 0.070 af Outflow=0.67 cfs 0.070 af Link 18L:Areas Combined Inflow=6.02 cfs 0.453 af Primary=6.02 cfs 0.453 af Total Runoff Area = 3.160 ac Runoff Volume = 0.454 af Average Runoff Depth = 1.72" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pane 7 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 2.08 cfs @ 11.99 hrs, Volume= 0.102 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 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1 S: Post Area 1-5 (Offsite, detained) Hydrograph •Runoff 12.08 cfs I 2- Type II 24-hr 1-Yr Rainfall=2.92" Runoff Area=0.890 ac Runoff Volume=0.102 af Runoff Depth>1.38" ° Tc=7.0 m i n L.- 1 CN=83 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) • Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 2.03 cfs @ 11.97 hrs, Volume= 0.101 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 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph ❑Runoff 12.03 cfs 2 j Type II 24-hr 1-Yr Rainfall=2.92" Runoff Area=0.610 ac Runoff Volume=0.101 af Runoff Depth>1.99" LL Tc=6.0 min CN=91 o /// ////////////////////////////////////////� 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-1 YR) Type II 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 1.40 cfs @ 11.97 hrs, Volume= 0.070 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 * 0.420 91 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph ❑Runoff I 1 ao cfs l Type II 24-hr 1-Yr Rainfall=2.92" Runoff Area=0.420 ac Runoff Volume=0.070 of Runoff Depth>1 .99" Tc=6.0 min CN=91 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-1 YR) Type II 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 3.68 cfs @ 11.97 hrs, Volume= 0.180 af, Depth> 1.75" 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 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Hydrograph 4 ❑Runoff` 13 68 cfs I rj Type II 24-hr 1-Yr Rainfall=2.92" 3 Runoff Area=1.240 ac Runoff Volume=0.180 of / Runoff Depth>1.75" 3 2 Tc=6.0 min CN=88 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-1 YR) Type 11 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Pond 19P: SWM 3 Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 1.63" for 1-Yr event Inflow = 4.10 cfs @ 11.98 hrs, Volume= 0.204 af Outflow = 1.98 cfs @ 12.08 hrs, Volume= 0.203 af, Atten= 52%, Lag= 6.2 min Primary = 1.98 cfs @ 12.08 hrs, Volume= 0.203 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=424.44'@ 12.08 hrs Surf.Area= 0.015 ac Storage= 0.039 af Plug-Flow detention time=8.0 min calculated for 0.203 af(100% of inflow) Center-of-Mass det. time=6.8 min ( 825.1 - 818.2 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round Culvert L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=1.97 cfs @ 12.08 hrs HW=424.42' (Free Discharge) L1=Culvert (Passes 1.97 cfs of 9.89 cfs potential flow) 12=Orifice/Grate (Orifice Controls 1.97 cfs @ 7.81 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 12 Pond 19P: SWM 3 Hydrograph / ■Inflow i a.10 cis i El Primary Inflow Area=1 .500 ac 4- Peak Elev=424.44' Storage=0.039 of 3- S u 3 - 1 1Be cis LT! 2- 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 13 Summary for Pond 20P: SWM 4 Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 1.99" for 1-Yr event Inflow = 1.40 cfs @ 11.97 hrs, Volume= 0.070 af Outflow = 0.67 cfs @ 12.07 hrs, Volume= 0.070 af, Atten= 52%, Lag= 6.2 min Primary = 0.67 cfs @ 12.07 hrs, Volume= 0.070 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 425.79'@ 12.07 hrs Surf.Area= 0.010 ac Storage= 0.014 af Plug-Flow detention time=8.1 min calculated for 0.070 af(100% of inflow) Center-of-Mass det. time=7.0 min ( 809.2 - 802.2 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.67 cfs @ 12.07 hrs HW=425.77' (Free Discharge) L1=CMP_Round 15" (Passes 0.67 cfs of 4.99 cfs potential flow) AL2=Orifice/Grate (Orifice Controls 0.67 cfs @ 6.06 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type I1 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 14 Pond 20P: SWM 4 Hydrograph Inflow 11.40cis I ❑Primary Inflow Area=0.420 ac Peak Elev=425.79' Storage=0.014 of U o 1 0.67 cfs LL 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-1 YR) Type 11 24-hr 1-Yr Rainfall=2.92" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 15 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 1.72" for 1-Yr event Inflow = 6.02 cfs @ 11.98 hrs, Volume= 0.453 af Primary = 6.02 cfs @ 11.98 hrs, Volume= 0.453 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 _1 Inflow 1602 as ❑Primary I602o6 Inflow Area=3.160 ac 6 5 4 N LT_ 3 2 We' iT 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-1 YR) Type ll 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 16 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 SubcatchmentI S: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>1.89" Tc=7.0 min CN=83 Runoff=2.84 cfs 0.140 of Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>2.58" Tc=6.0 min CN=91 Runoff=2.59 cfs 0.131 of Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>2.58" Tc=6.0 min CN=91 Runoff=1.78 cfs 0.090 of Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>2.30" Tc=6.0 min CN=88 Runoff=4.80 cfs 0.238 of Pond 19P: SWM 3 Peak Elev=424.93' Storage=0.046 of Inflow=5.40 cfs 0.271 af Outflow=4.61 cfs 0.271 of Pond 20P: SWM 4 Peak Elev=426.34' Storage=0.019 af Inflow=1.78 cfs 0.090 of Outflow=0.78 cfs 0.090 of Link 18L:Areas Combined Inflow=8.80 cfs 0.599 af Primary=8.80 cfs 0.599 of Total Runoff Area = 3.160 ac Runoff Volume = 0.599 af Average Runoff Depth = 2.28" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 1 S: Post Area 1-5 (Offsite, detained) Runoff = 2.84 cfs @ 11.98 hrs, Volume= 0.140 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-5 (Offsite, detained) Hydrograph L.01Jnof 3 12.84 cfs Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=0.890 ac 2 Runoff Volume=0.140 of Runoff Depth>1 .89" Tc=7.0 min CN=83 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pane 18 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 2.59 cfs @ 11.97 hrs, Volume= 0.131 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph El Runoff 12.59 cfs Type II 24-hr 2-YR Rainfall=3.54" 2 Runoff Area=0.610 ac Runoff Volume=0.131 af Runoff Depth>2.58" LL Tc=6.0 min 1 CN=91 r/ 0 / z 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-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 1.78 cfs @ 11.97 hrs, Volume= 0.090 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 0.420 91 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph / ❑Runoff 11.78 cfs I Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=0.420 ac Runoff Volume=0.090 af Runoff Depth>2.58" ° Tc=6.0 min LL CN=91 0 .Dl/////// 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-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 4.80 cfs @ 11.97 hrs, Volume= 0.238 af, Depth> 2.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description * 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Hydrograph ❑Runoff 5 l 4 80 cfs I Type II 24-hr 2-YR Rainfall=3.54" 4-Runoff Area=1.240 ac Runoff Volume=0.238 af 3- Runoff Depth>2.30" LL - Tc=6.0 m i n 2 CN=88 1 '' o %/////////////////////////// // // 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-1 YR) Type ll 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 21 Summary for Pond 19P: SWM 3 Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 2.17" for 2-YR event Inflow = 5.40 cfs @ 11.98 hrs, Volume= 0.271 af Outflow = 4.61 cfs @ 12.04 hrs, Volume= 0.271 af, Atten= 15%, Lag= 4.0 min Primary = 4.61 cfs @ 12.04 hrs, Volume= 0.271 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=424.93'@ 12.04 hrs Surf.Area= 0.014 ac Storage= 0.046 af Plug-Flow detention time=7.7 min calculated for 0.271 af(100% of inflow) Center-of-Mass det. time=6.7 min ( 817.2 - 810.6 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round Culvert L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends& connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=4.39 cfs @ 12.04 hrs HW=424.91' (Free Discharge) 4P-1=Culvert (Passes 4.39 cfs of 10.96 cfs potential flow) I2=Orifice/Grate (Orifice Controls 2.15 cfs @ 8.52 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 2.24 cfs @ 1.82 fps) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 22 Pond 19P: SWM 3 Hydrograph 6 1 Inflow 5.40crs ❑Primary Inflow Area=1 .500 ac 5 14.61cfs 4 Peak Elev=424.93' Storage=0.046 of N V 3 3 0 LL 2 At.04 A 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-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond 20P: SWM 4 Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 2.58" for 2-YR event Inflow = 1.78 cfs @ 11.97 hrs, Volume= 0.090 af Outflow = 0.78 cfs @ 12.08 hrs, Volume= 0.090 af, Atten= 56%, Lag= 6.7 min Primary = 0.78 cfs @ 12.08 hrs, Volume= 0.090 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 426.34'@ 12.08 hrs Surf.Area= 0.010 ac Storage= 0.019 af Plug-Flow detention time=9.2 min calculated for 0.090 af(100% of inflow) Center-of-Mass det. time=8.2 min ( 803.1 - 795.0 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.78 cfs @ 12.08 hrs HW=426.32' (Free Discharge) t-1=CMP_Round 15" (Passes 0.78 cfs of 6.08 cfs potential flow) AL2=Orifice/Grate (Orifice Controls 0.78 cfs @ 7.04 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 24 Pond 20P: SWM 4 Hydrograph / l Inflow i 78 rfs ❑Primary Inflow Area=0.420 ac Peak Elev=426.34' Storage=0.019 of 3 1 E_O 0.78 ds 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Pane 25 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 2.27" for 2-YR event Inflow = 8.80 cfs @ 12.01 hrs, Volume= 0.599 af Primary = 8.80 cfs @ 12.01 hrs, Volume= 0.599 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 / ■Inflow II l 8.81?cfs J ■Primary Inflow Area=3.1 60'8 80 cfs 8- 7- L6- N V 5- 3 0 u 4- 3] 2 1 o 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-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 26 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 SubcatchmentlS: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>3.49" Tc=7.0 min CN=83 Runoff=5.12 cfs 0.259 of Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>4.32" Tc=6.0 min CN=91 Runoff=4.20 cfs 0.220 of Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>4.32" Tc=6.0 min CN=91 Runoff=2.89 cfs 0.151 of Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>4.00" Tc=6.0 min CN=88 Runoff=8.10 cfs 0.413 of Pond 19P: SWM 3 Peak Elev=425.32' Storage=0.051 af Inflow=9.19 cfs 0.478 af Outflow=9.83 cfs 0.478 af Pond 20P: SWM 4 Peak Elev=427.94' Storage=0.032 af Inflow=2.89 cfs 0.151 af Outflow=2.61 cfs 0.151 af Link 18L:Areas Combined Inflow=18.93 cfs 1.042 af Primary=18.93 cfs 1.042 af Total Runoff Area = 3.160 ac Runoff Volume= 1.043 af Average Runoff Depth = 3.96" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 5.12 cfs @ 11.98 hrs, Volume= 0.259 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1 S: Post Area 1-5 (Offsite, detained) Hydrograph ❑Runoff !suds 5 Type II 24-hr 10-Yr Rainfall=5.35" 4 Runoff Area=0.890 ac Runoff Volume=0.259 af 3 Runoff Depth>3.49" LL Tc=7.0 m i n 2 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 4.20 cfs @ 11.96 hrs, Volume= 0.220 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph / ❑Runoff` I420cfs I 4- Type II 24-hr 10-Yr Rainfall=5.35" Runoff Area=0.610 ac 3- Runoff Volume=0.220 af Runoff Depth>4.32" 0 - Tc=6.0 min LL 2_ CN=91 1 . 0 r Tl/ , ///i/iiiiise -` riii 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-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 29 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 2.89 cfs @ 11.96 hrs, Volume= 0.151 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 * 0.420 91 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph ❑Runoff 3 12.89 cfs I Type II 24-hr 10-Yr Rainfall=5.35" Runoff Area=0.420 ac 2 Runoff Volume=0.151 af Runoff Depth>4.32" LL Tc=6.0 min CN=91 4, 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 8.10 cfs @ 11.97 hrs, Volume= 0.413 af, Depth> 4.00" 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 * 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Hydrograph 9 ❑Runoff` [810,ep 8 Type II 24-hr 7 10-Yr Rainfall=5.35" Runoff Area=1.240 ac 6 Runoff Volume=0.413 af 5 / Runoff Depth>4.00" 4- Tc=6.0 min 3- CN=88 2- 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-1 YR) Type 1124-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 31 Summary for Pond 19P: SWM 3 [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 3.83" for 10-Yr event Inflow = 9.19 cfs @ 11.97 hrs, Volume= 0.478 af Outflow = 9.83 cfs @ 11.97 hrs, Volume= 0.478 af, Atten= 0%, Lag= 0.0 min Primary = 9.83 cfs @ 11.97 hrs, Volume= 0.478 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=425.32'@ 11.97 hrs Surf.Area= 0.011 ac Storage= 0.051 af Plug-Flow detention time=6.6 min calculated for 0.478 af(100% of inflow) Center-of-Mass det. time=5.7 min ( 801.0 - 795.4 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round Culvert L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=9.11 cfs @ 11.97 hrs HW=425.26' (Free Discharge) L1=Culvert (Passes 9.11 cfs of 11.66 cfs potential flow) L2=Orifice/Grate (Orifice Controls 2.27 cfs @ 8.98 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 6.84 cfs @ 2.66 fps) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 32 Pond 19P: SWM 3 / Hydrograph 11J ■Inflow ` i0 Primary) 107 Iyn 71Ts, Inflow Area=1 .500 ac 9- i Peak Elev=425.32' Storage=0.051 of 7= / u 6- O• 5- LL 4 3- 2- 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type Il 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 33 Summary for Pond 20P: SWM 4 Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 4.32" for 10-Yr event Inflow = 2.89 cfs @ 11.96 hrs, Volume= 0.151 af Outflow = 2.61 cfs @ 12.05 hrs, Volume= 0.151 af, Atten= 10%, Lag= 5.0 min Primary = 2.61 cfs @ 12.05 hrs, Volume= 0.151 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 427.94'@ 12.04 hrs Surf.Area= 0.002 ac Storage= 0.032 af Plug-Flow detention time=10.2 min calculated for 0.151 af(100% of inflow) Center-of-Mass det. time=9.3 min ( 790.1 - 780.7 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends& connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=2.51 cfs @ 12.05 hrs HW=427.92' (Free Discharge) L1=CMP_Round 15" (Passes 2.51 cfs of 8.46 cfs potential flow) I2=Orifice/Grate (Orifice Controls 1.03 cfs @ 9.30 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 1.48 cfs @ 1.84 fps) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 34 Pond 20P: SWM 4 Hydrograph / •Inflow zee-fs IS Primary 3 Inflow Area=0.420 ac Izfi,°'= Peak Elev=427.94' Storage=0.032 of 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 35 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 3.96" for 10-Yr event Inflow = 18.93 cfs @ 11.97 hrs, Volume= 1.042 of Primary = 18.93 cfs @ 11.97 hrs, Volume= 1.042 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 / •Inflow II 21- 18.93cfs I ®Primary 20 I1893cfs. Inflow Area=3.160 ac 19= 18= 17= 16= 15= 14= 13: N 12- 2 11- c 10- LL 9= 8= 7 6- 5= 4= 3= 2= 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type ll 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 36 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 SubcatchmentlS: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>6.74" Tc=7.0 min CN=83 Runoff=9.52 cfs 0.500 af Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>7.71" Tc=6.0 min CN=91 Runoff=7.22 cfs 0.392 af Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>7.71" Tc=6.0 min CN=91 Runoff=4.97 cfs 0.270 af Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>7.35" Tc=6.0 min CN=88 Runoff=14.31 cfs 0.759 of Pond 19P: SWM 3 Peak Elev=428.78' Storage=0.057 af Inflow=16.55 cfs 0.891 af Outflow=17.24 cfs 0.890 af Pond 20P: SWM 4 Peak Elev=428.37' Storage=0.032 af Inflow=4.97 cfs 0.270 af Outflow=6.48 cfs 0.269 af Link 18L:Areas Combined Inflow=36.39 cfs 1.919 af Primary=36.39 cfs 1.919 af Total Runoff Area= 3.160 ac Runoff Volume = 1.920 af Average Runoff Depth = 7.29" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 11 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 37 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 9.52 cfs @ 11.98 hrs, Volume= 0.500 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-5 (Offsite, detained) Hydrograph ❑Runoff` 10 19 52 cfs I Type II 24-hr 9 100-Yr Rainfall=8.80" 8- Runoff Area=0.890 ac v Runoff Volume=0.500 af 6: Runoff Depth>6.74" 0 5= Tc=7.0 min LL CN=83 2- 44 0 //////fib.. o�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-1 YR) Type II 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 38 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 7.22 cfs @ 11.96 hrs, Volume= 0.392 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph 8 ❑Runoff` 17.22 cfs I 7 Type II 24-hr 100-Yr Rainfall=8.80" 6 Runoff Area=0.610 ac 5 Runoff Volume=0.392 af Runoff Depth>7.71" 3 4. LL Tc=6.0 min 3= CN=91 2 14 rAv o 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-1 YR) Type II 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 39 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 4.97 cfs @ 11.96 hrs, Volume= 0.270 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 * 0.420 91 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph 0 Runoff 1 4.97 cfs I 5- Type II 24-hr 100-Yr Rainfall=8.80" 4_ Runoff Area=0.420 ac Runoff Volume=0.270 af ti 3 Runoff Depth>7.71" ° Tc-6.0 m i n LL 2- CN=91 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 40 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 14.31 cfs @ 11.96 hrs, Volume= 0.759 af, Depth> 7.35" 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 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) / Hydrograph 16J 0 Runoff 15- 1 14.31 cfs I 14" Type II 24-hr 13_ 100-Yr Rainfall=8.80" 127 11 Runoff Area=1.240 ac 10, Runoff Volume=0.759 af Runoff Depth>7.35" 8= it) 7' Tc=6.0 min CN=88 4 3= 2= 1] 0f/����f������ 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-1 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 41 Summary for Pond 19P: SWM 3 [93] Warning: Storage range exceeded by 2.78' [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 7.13" for 100-Yr event Inflow = 16.55 cfs @ 11.97 hrs, Volume= 0.891 af Outflow = 17.24 cfs @ 11.99 hrs, Volume= 0.890 af, Atten= 0%, Lag= 1.0 min Primary = 17.24 cfs @ 11.99 hrs, Volume= 0.890 of Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 428.78'@ 11.99 hrs Surf.Area= 0.000 ac Storage= 0.057 af Plug-Flow detention time=5.7 min calculated for 0.889 af(100% of inflow) Center-of-Mass det. time=4.9 min ( 783.9 - 779.0 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round Culvert L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=16.61 cfs @ 11.99 hrs HW=428.36' (Free Discharge) 4-1=Culvert (Inlet Controls 16.61 cfs @ 9.40 fps) L2=Orifice/Grate (Passes < 3.11 cfs potential flow) 3=Sharp-Crested Rectangular Weir(Passes < 77.45 cfs potential flow) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 42 Pond 19P: SWM 3 Hydrograph / •Inflow ` 19= p Primary 16- '".Z°ci5 ' Inflow Area=1 .500 ac 17: r 16 Peak Elev=428.78' 15= 14- I Storage=0.057 of 13.. 12; m 11-E '99- 10 E O 9= LL 8_ 7 6- 5.'_'. 4- 3.' 2.' 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) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type II 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 43 Summary for Pond 20P: SWM 4 [93] Warning: Storage range exceeded by 0.37' [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 7.71" for 100-Yr event Inflow = 4.97 cfs © 11.96 hrs, Volume= 0.270 af Outflow = 6.48 cfs @ 11.95 hrs, Volume= 0.269 af, Atten= 0%, Lag= 0.0 min Primary = 6.48 cfs @ 11.95 hrs, Volume= 0.269 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 428.37'@ 11.95 hrs Surf.Area= 0.000 ac Storage= 0.032 af Plug-Flow detention time=8.5 min calculated for 0.269 af(100% of inflow) Center-of-Mass det. time=7.8 min ( 773.6 - 765.8 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert= 424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends& connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=6.27 cfs @ 11.95 hrs HW=428.35' (Free Discharge) 4-1=CMP_Round 15" (Passes 6.27 cfs of 9.00 cfs potential flow) '2=Orifice/Grate (Orifice Controls 1.08 cfs @ 9.82 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 5.19 cfs @ 2.83 fps) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 sin 06538 ©2017 HydroCAD Software Solutions LLC Page 44 Pond 20P: SWM 4 Hydrograph .1 Inflow 7- 0 Primary 648c`s' Inflow Area=0.420 ac 6- Peak EIev=428.37' cis 5- Storage=0.032 of - 4- 2. o - aL 3- 2- / P 1- i: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Time (hours) Keswick Hall_Spa_Analysis Points 1 (POST-1 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 45 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 7.29" for 100-Yr event Inflow = 36.39 cfs @ 11.97 hrs, Volume= 1.919 af Primary = 36.39 cfs @ 11.97 hrs, Volume= 1.919 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 / ■Inflow II 40- 136.39 cfs I ■Primary 38_ I3639cfs Inflow Area=3.160 ac 36. 341 32 301 28= 261 is 22= • 201 o LL 18 161. 14= 12- 10= 8 6 4 2 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) 0 Post Area 1-5 (Offsite, detained) fa ------------------4/9SWM 3 18L 4-.---------- 0 Post Area 1-6 (Onsite, ----\__ Post Area 1-8 (Onsite, Detained) Areas Combined Undetained) 0' <16S> SWM 4 Post Area 1-7 (Onsite, Detained) 4ubca t Reach eon• Link Routing Diagram for Keswick Hall_Spa_Analysis Points 1 (POST-10 YP,) �� Prepared by Timmons Group, Printed 10/22/2018 HydroCAD®10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.890 83 VRRM SPREADSHEET D.A. A (1S) 0.610 91 VRRM SPREADSHEET D.A. B (2S) 0.420 92 VRRM SPREADSHEET D.A. C (16S) 1.240 88 VRRM SPREADSHEET D.A. D (17S) 3.160 88 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 3.160 Other 1 S, 2S, 16S, 17S 3.160 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC 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 0.890 0.890 VRRM SPREADSHEET D.A. A 1S 0.000 0.000 0.000 0.000 0.610 0.610 VRRM SPREADSHEET D.A. B 2S 0.000 0.000 0.000 0.000 0.420 0.420 VRRM SPREADSHEET D.A. C 16 S 0.000 0.000 0.000 0.000 1.240 1.240 VRRM SPREADSHEET D.A. D 17 S 0.000 0.000 0.000 0.000 3.160 3.160 TOTAL AREA Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 421.50 419.50 100.0 0.0200 0.013 18.0 0.0 0.0 2 20P 424.00 422.00 100.0 0.0200 0.013 15.0 0.0 0.0 Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©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 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>1.89" Tc=7.0 min CN=83 Runoff=2.84 cfs 0.140 af Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>2.58" Tc=6.0 min CN=91 Runoff=2.59 cfs 0.131 af Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>2.67" Tc=6.0 min CN=92 Runoff=1.83 cfs 0.094 af Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>2.30" Tc=6.0 min CN=88 Runoff=4.80 cfs 0.238 af Pond 19P: SWM 3 Peak Elev=424.93' Storage=0.046 af Inflow=5.40 cfs 0.271 af Outflow=4.61 cfs 0.271 af Pond 20P: SWM 4 Peak Elev=426.42' Storage=0.020 af Inflow=1.83 cfs 0.094 af Outflow=0.80 cfs 0.093 af Link 18L:Areas Combined Inflow=8.81 cfs 0.602 af Primary=8.81 cfs 0.602 af Total Runoff Area = 3.160 ac Runoff Volume= 0.603 af Average Runoff Depth = 2.29" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 11 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 2.84 cfs @ 11.98 hrs, Volume= 0.140 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-5 (Offsite, detained) Hydrograph / ❑Runoff` 3 12 84 cis 1 Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=0.890 ac 2- Runoff Volume=0.140 af Runoff Depth>1 .89" Tc=7.0 min 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 2.59 cfs @ 11.97 hrs, Volume= 0.131 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph ❑Runoff 12 59 cfs I Type II 24-hr 2-YR Rainfall=3.54" 2 Runoff Area=0.610 ac Runoff Volume=0.131 af / Runoff Depth>2.58" Tc=6.0 min CN=91 o ///////////////////////////////.. e��.•���J////////////////////// 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-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 1.83 cfs @ 11.96 hrs, Volume= 0.094 af, Depth> 2.67" 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 2-YR Rainfall=3.54" Area (ac) CN Description * 0.420 92 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph 2 ❑Runoff 1 83 cfs Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=0.420 ac Runoff Volume=0.094 af Runoff Depth>2.67" LL Tc=6.0 min CN=92 40 /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-10 YR) Type II 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 4.80 cfs @ 11.97 hrs, Volume= 0.238 af, Depth> 2.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.54" Area (ac) CN Description 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Hydrograph ❑Runoff 5 148ocrs I 4 Type II 24-hr 2-YR Rainfall=3.54" Runoff Area=1.240 ac Runoff Volume=0.238 af 3- Runoff Depth>2.30" Tc=6.0 min LL i 2- CN=88 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-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Pond 19P: SWM 3 Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 2.17" for 2-YR event Inflow = 5.40 cfs @ 11.98 hrs, Volume= 0.271 af Outflow = 4.61 cfs @ 12.04 hrs, Volume= 0.271 af, Atten= 15%, Lag= 4.0 min Primary = 4.61 cfs @ 12.04 hrs, Volume= 0.271 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 424.93'@ 12.04 hrs Surf.Area= 0.014 ac Storage= 0.046 af Plug-Flow detention time=7.7 min calculated for 0.271 af(100% of inflow) Center-of-Mass det. time=6.7 min ( 817.2 - 810.6 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round CMP_Round 18" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=4.39 cfs @ 12.04 hrs HW=424.91' (Free Discharge) L1=CMP_Round 18" (Passes 4.39 cfs of 10.96 cfs potential flow) ' 2=Orifice/Grate (Orifice Controls 2.15 cfs @ 8.52 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 2.24 cfs @ 1.82 fps) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 12 Pond 19P: SWM 3 // Hydrograph ./ I Inflow 6 I 540 cfs i ❑Primary Inflow Area=1 .500 ac 5 l461cfs Peak Elev=424.93' Storage=0.046 of 4 U, U 3 3 0 2 1 1 s .00746, 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 13 Summary for Pond 20P: SWM 4 Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 2.67" for 2-YR event Inflow = 1.83 cfs @ 11.96 hrs, Volume= 0.094 af Outflow = 0.80 cfs @ 12.08 hrs, Volume= 0.093 af, Atten= 57%, Lag= 6.7 min Primary = 0.80 cfs @ 12.08 hrs, Volume= 0.093 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 426.42'@ 12.08 hrs Surf.Area= 0.010 ac Storage= 0.020 af Plug-Flow detention time=9.3 min calculated for 0.093 af(100% of inflow) Center-of-Mass det. time=8.3 min ( 798.7 - 790.4 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.79 cfs @ 12.08 hrs HW=426.40' (Free Discharge) L1=CMP_Round 15" (Passes 0.79 cfs of 6.22 cfs potential flow) -2=Orifice/Grate (Orifice Controls 0.79 cfs @ 7.17 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type ll 24-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 14 Pond 20P: SWM 4 Hydrograph / ■Inflow 2- l i e3 cf:i •Primary� Inflow Area=0.420 ac Peak Elev=426.42' Storage=0.020 of i U 3 1 a LL (0.80 cfs 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 2-YR Rainfall=3.54" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 15 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 2.29" for 2-YR event Inflow = 8.81 cfs @ 12.01 hrs, Volume= 0.602 af Primary = 8.81 cfs @ 12.01 hrs, Volume= 0.602 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 ®Inflow 8 81 cfs O Primary 9 Inflow Area=3.16018car1-1- 8- 7- 6- C 5- '_u_ 3- ir 1 Ai 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-10 YR) Type 1124-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 16 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 SubcatchmentlS: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>3.49" Tc=7.0 min CN=83 Runoff=5.12 cfs 0.259 af Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>4.32" Tc=6.0 min CN=91 Runoff=4.20 cfs 0.220 af Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>4.43" Tc=6.0 min CN=92 Runoff=2.93 cfs 0.155 af Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>4.00" Tc=6.0 min CN=88 Runoff=8.10 cfs 0.413 af Pond 19P: SWM 3 Peak Elev=425.32' Storage=0.051 af Inflow=9.19 cfs 0.478 af Outflow=9.83 cfs 0.478 af Pond 20P: SWM 4 Peak Elev=427.94' Storage=0.032 af Inflow=2.93 cfs 0.155 af Outflow=2.56 cfs 0.155 af Link 18L:Areas Combined Inflow=19.02 cfs 1.046 af Primary=19.02 cfs 1.046 af Total Runoff Area = 3.160 ac Runoff Volume = 1.046 af Average Runoff Depth = 3.97" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 17 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 5.12 cfs @ 11.98 hrs, Volume= 0.259 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1S: Post Area 1-5 (Offsite, detained) Hydrograph ❑Runoff 1512 cfs I 5 Type II 24-hr 10-Yr Rainfall=5.35" 4 Runoff Area=0.890 ac Runoff Volume=0.259 af 3 Runoff Depth>3.49" Tc=7.0 min 2 / 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 4.20 cfs @ 11.96 hrs, Volume= 0.220 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph ❑Runoff 14.20 crs I 4 j Type II 24-hr 10-Yr Rainfall=5.35" Runoff Area=0.610 ac 3 Runoff Volume=0.220 af / Runoff Depth>4.32" 2 Tc=6.0 min CN=91 /o 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 HaII_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 2.93 cfs @ 11.96 hrs, Volume= 0.155 af, Depth> 4.43" 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 0.420 92 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph ❑Runoff 3 2.9;Os Type II 24-hr 10-Yr Rainfall=5.35" Runoff Area=0.420 ac 2 Runoff Volume=0.155 of Runoff Depth>4.43" LL Tc=6.0 m i n CN=92 ii 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-10 YR) Type /l 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 8.10 cfs @ 11.97 hrs, Volume= 0.413 af, Depth> 4.00" 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 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Hydrograph 9 ❑Runoff Ie was I 8 Type II 24-hr 10-Yr Rainfall=5.35" Runoff Area=1.240 ac Runoff Volume=0.413 af f Runoff Depth>4.00" Tc=6.0 m i n LL 4 CN=88 2- 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-10 YR) Type 1124-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 21 Summary for Pond 19P: SWM 3 [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 3.83" for 10-Yr event Inflow = 9.19 cfs @ 11.97 hrs, Volume= 0.478 af Outflow = 9.83 cfs @ 11.97 hrs, Volume= 0.478 af, Atten= 0%, Lag= 0.0 min Primary = 9.83 cfs @ 11.97 hrs, Volume= 0.478 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=425.32'@ 11.97 hrs Surf.Area= 0.011 ac Storage= 0.051 af Plug-Flow detention time=6.6 min calculated for 0.478 af(100% of inflow) Center-of-Mass det. time=5.7 min ( 801.0 - 795.4 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round CMP_Round 18" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends & connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=9.11 cfs @ 11.97 hrs HW=425.26' (Free Discharge) L1=CMP_Round 18" (Passes 9.11 cfs of 11.66 cfs potential flow) AL2=Orifice/Grate (Orifice Controls 2.27 cfs @ 8.98 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 6.84 cfs @ 2.66 fps) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 22 Pond 19P: SWM 3 / Hydrograph 11J 7 Inflow ` ❑Primary 10- 98.cfSMIIInflow Area=1 .500 ac Peak Elev=425.32' 8= Storage=0.051 of 71 YI � 6- 3 g 5 4 3 2 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCADO 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond 20P: SWM 4 Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 4.43" for 10-Yr event Inflow = 2.93 cfs @ 11.96 hrs, Volume= 0.155 of Outflow = 2.56 cfs @ 12.04 hrs, Volume= 0.155 af, Atten= 13%, Lag= 4.8 min Primary = 2.56 cfs @ 12.04 hrs, Volume= 0.155 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev=427.94'@ 12.04 hrs Surf.Area= 0.003 ac Storage= 0.032 af Plug-Flow detention time=10.2 min calculated for 0.154 af(100% of inflow) Center-of-Mass det. time=9.3 min ( 785.9 - 776.6 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/ Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends& connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=2.41 cfs @ 12.04 hrs HW=427.90' (Free Discharge) L1=CMP_Round 15" (Passes 2.41 cfs of 8.45 cfs potential flow) "2=Orifice/Grate (Orifice Controls 1.02 cfs @ 9.28 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 1.38 cfs @ 1.80 fps) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type ll 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 24 Pond 20P: SWM 4 Hydrograph / ❑Inflow 11 2.93rfs' CIPrimary y.� 3 Inflow Area=0.420 ac 125 Peak Elev=427.94' Storage=0.032 of 2 3 y LL i.... ....r....�.�-..T,......,.�........,i....�....�.,..�....�....i..J/ 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 10-Yr Rainfall=5.35" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 25 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 3.97" for 10-Yr event Inflow = 19.02 cfs @ 11.97 hrs, Volume= 1.046 af Primary = 19.02 cfs @ 11.97 hrs, Volume= 1.046 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 / ■Inflow 21= 9 02 rs ❑Primary 2 1,9°2j Inflow Area=3.160 ac 19= � 18= 17= 16= I/1 14= 13= n 12. `- 11 10 LL 9 8 { 7 6 5 4 3 2 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 26 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 SubcatchmentlS: Post Area 1-5(Offsite, Runoff Area=0.890 ac 0.00% Impervious Runoff Depth>6.74" Tc=7.0 min CN=83 Runoff=9.52 cfs 0.500 af Subcatchment2S: Post Area 1-6(Onsite, Runoff Area=0.610 ac 0.00% Impervious Runoff Depth>7.71" Tc=6.0 min CN=91 Runoff=7.22 cfs 0.392 af Subcatchment16S: Post Area 1-7(Onsite, Runoff Area=0.420 ac 0.00% Impervious Runoff Depth>7.83" Tc=6.0 min CN=92 Runoff=5.00 cfs 0.274 af Subcatchment17S: Post Area 1-8(Onsite, Runoff Area=1.240 ac 0.00% Impervious Runoff Depth>7.35" Tc=6.0 min CN=88 Runoff=14.31 cfs 0.759 af Pond 19P: SWM 3 Peak Elev=428.78' Storage=0.057 af Inflow=16.55 cfs 0.891 af Outflow=17.24 cfs 0.890 af Pond 20P: SWM 4 Peak Elev=428.36' Storage=0.032 af Inflow=5.00 cfs 0.274 af outflow=6.39 cfs 0.274 af Link 18L:Areas Combined Inflow=36.31 cfs 1.923 af Primary=36.31 cfs 1.923 af Total Runoff Area = 3.160 ac Runoff Volume = 1.925 af Average Runoff Depth = 7.31" 100.00% Pervious = 3.160 ac 0.00% Impervious = 0.000 ac Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 11 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 27 Summary for Subcatchment 1S: Post Area 1-5 (Offsite, detained) Runoff = 9.52 cfs @ 11.98 hrs, Volume= 0.500 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 * 0.890 83 VRRM SPREADSHEET D.A. A 0.890 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.0 Direct Entry, Subcatchment 1 S: Post Area 1-5 (Offsite, detained) Hydrograph ❑Runoff 10 19.52 crs Type II 24-hr 100-Yr Rainfall=8.80" 8- Runoff Area=0.890 ac V Runoff Volume=0.500 af 13 6= Runoff Depth>6.74" ° 5- Tc=7.0 min LL 4- // CN=83 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-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 28 Summary for Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Runoff = 7.22 cfs @ 11.96 hrs, Volume= 0.392 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 * 0.610 91 VRRM SPREADSHEET D.A. B 0.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: Post Area 1-6 (Onsite, Detained) Hydrograph 8 ❑Runoff 17 22 ors 7 Type II 24-hr 100-Yr Rainfall=8.80" 6 Runoff Area=0.610 ac 5= Runoff Volume=0.392 af Runoff Depth>7.71" 4 1 Tc=6.0 min Li 3 CN=91 2 '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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 29 Summary for Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Runoff = 5.00 cfs @ 11.96 hrs, Volume= 0.274 af, Depth> 7.83" 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 * 0.420 92 VRRM SPREADSHEET D.A. C 0.420 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 16S: Post Area 1-7 (Onsite, Detained) Hydrograph 0 Runoff 00 cfs 5 5Type II 24-hr 100-Yr Rainfall=8.80" 4 Runoff Area=0.420 ac Runoff Volume=0.274 af 3 / Runoff Depth>7.83" Tc=6.0 min 2 CN=92 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-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) Runoff = 14.31 cfs @ 11.96 hrs, Volume= 0.759 af, Depth> 7.35" 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 1.240 88 VRRM SPREADSHEET D.A. D 1.240 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 17S: Post Area 1-8 (Onsite, Undetained) / Hydrograph 16-! ❑Runoff 15 11431 cfs I 14= J Type II 24-hr 13- 100-Yr Rainfall=8.80" 12= Runoff Area=1.240 ac Runoff Volume=0.759 af ,✓ Runoff Depth>7.35" 3 LL Tc=6.0 m i n CN=88 4= 3= 1= / 0-1.6������1����1���f�� 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-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 31 Summary for Pond 19P: SWM 3 [93] Warning: Storage range exceeded by 2.78' [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.500 ac, 0.00% Impervious, Inflow Depth > 7.13" for 100-Yr event Inflow = 16.55 cfs @ 11.97 hrs, Volume= 0.891 af Outflow = 17.24 cfs @ 11.99 hrs, Volume= 0.890 af, Atten= 0%, Lag= 1.0 min Primary = 17.24 cfs @ 11.99 hrs, Volume= 0.890 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 428.78'@ 11.99 hrs Surf.Area= 0.000 ac Storage= 0.057 af Plug-Flow detention time=5.7 min calculated for 0.889 af(100% of inflow) Center-of-Mass det. time=4.9 min ( 783.9 - 779.0 ) Volume Invert Avail.Storage Storage Description #1 421.50' 0.057 af 54.0" Round CMP_Round 54" L= 155.0' Device Routing Invert Outlet Devices #1 Primary 421.50' 18.0" Round CMP_Round 18" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert= 421.50'/419.50' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.77 sf #2 Device 1 421.50' 6.8"Vert. Orifice/Grate C= 0.600 #3 Device 1 424.60' 4.0' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=16.61 cfs @ 11.99 hrs HW=428.36' (Free Discharge) t-1=CMP_Round 18" (Inlet Controls 16.61 cfs @ 9.40 fps) I2=Orifice/Grate (Passes < 3.11 cfs potential flow) 3=Sharp-Crested Rectangular Weir(Passes < 77.45 cfs potential flow) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type ll 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 32 Pond 19P: SWM 3 Hydrograph II 19 e Primary 18- 1 72;4cfs s Inflow Area=1 .500 ac 17= 1 6= Peak Elev=428.78' 15= 14= Storage=0.057 of 13= 12= 11- 111 0 9- LL 8— 4= 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type II 24-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 33 Summary for Pond 20P: SWM 4 [93] Warning: Storage range exceeded by 0.36' [88] Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 0.420 ac, 0.00% Impervious, Inflow Depth > 7.83" for 100-Yr event Inflow = 5.00 cfs @ 11.96 hrs, Volume= 0.274 af Outflow = 6.39 cfs @ 11.95 hrs, Volume= 0.274 af, Atten= 0%, Lag= 0.0 min Primary = 6.39 cfs @ 11.95 hrs, Volume= 0.274 af Routing by Stor-Ind method, Time Span= 0.00-24.00 hrs, dt= 0.05 hrs Peak Elev= 428.36'@ 11.95 hrs Surf.Area= 0.000 ac Storage= 0.032 af Plug-Flow detention time=8.5 min calculated for 0.274 af(100% of inflow) Center-of-Mass det. time=7.7 min ( 770.1 - 762.4 ) Volume Invert Avail.Storage Storage Description #1 424.00' 0.032 af 48.0" Round CMP_Round 48" L= 110.0' Device Routing Invert Outlet Devices #1 Primary 424.00' 15.0" Round CMP_Round 15" L= 100.0' CMP, projecting, no headwall, Ke= 0.900 Inlet/Outlet Invert=424.00'/422.00' S= 0.0200'/' Cc= 0.900 n= 0.013 Concrete pipe, bends&connections, Flow Area= 1.23 sf #2 Device 1 424.00' 4.5"Vert. Orifice/Grate C= 0.600 #3 Device 1 427.60' 2.6' long Sharp-Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=6.19 cfs @ 11.95 hrs HW=428.34' (Free Discharge) L1=CMP_Round 15" (Passes 6.19 cfs of 8.99 cfs potential flow) -2=Orifice/Grate (Orifice Controls 1.08 cfs @ 9.81 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 5.11 cfs @ 2.81 fps) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 34 Pond 20P: SWM 4 Hydrograph J Inflow y 7 ❑Primary - fs Inflow Area=0.420 ac 6 s_ Peak Elev=428.36' 5 Storage=0.032 of w 4 O U. 3 2 1 A 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) Keswick Hall_Spa_Analysis Points 1 (POST-10 YR) Type 1124-hr 100-Yr Rainfall=8.80" Prepared by Timmons Group Printed 10/22/2018 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 35 Summary for Link 18L: Areas Combined Inflow Area = 3.160 ac, 0.00% Impervious, Inflow Depth > 7.30" for 100-Yr event Inflow = 36.31 cfs @ 11.97 hrs, Volume= 1.923 af Primary = 36.31 cfs @ 11.97 hrs, Volume= 1.923 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 / •Inflow 40= 136.31 cfs I ❑Primary 36' 1363,crs Inflow Area=3.160 ac 36= 34 32' 30: 28' 26' 24= u• 22: 20= u. 16 16- 14= 12= 10- 8= 4= 2= 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) "Tomorrow's Natural Resources Today" 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: 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. ScottA. Reed. Scott A. Reed Vice President Chesapeake Bay Nutrient LandTrust, LLC. • 5735 S.Laburnum Avenue • Richmond,VA 23231 • P:804.222.5114 • www.cbnit.com