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Home My WebLink AboutWPO200700078 Calculations 2007-11-20 AMENDMENT TO HYDROLOGIC/HYDRAULIC CALCULATIONS FOR Luxor Subdivision & Road Networks November 20, 2007 LOCATION: Tax Map 78 Parcels 12B Albemarle County, Virginia PREPARED BY: i, Dominion Development Resources, LLC ;;. ,j>° 172 S. Pantops Drive i- Charlottesville, VA 22911 P: 434.979.8121 F: 434.979.1681 E C• at. lIzA 07 Run—off Summary Point of Pre-Dev Pre-Dev Pre-Dev Post - Post-Dev Post-Dev Analysis DA 2-Year 10-Year Dev Rtd. 2- Rtd. 10- DA Year Year Outfall 3 3 26.71 37.38 3 Post 9.49 16. 87 Outfall 2 2 77.46 111.13 2 Post & 61. 11 65.70 SWM#3 Outfall 1 1 122.88 175.25 Fontana 107. 94 142.72 Pond, 1, & SWM2 Luxor Subdivision Index Index: 2 Summary: 3 Stormwater Management Pond #3 Pre-Development: Flood Hydrographs: 4-6 Post-Development: Flood Hydrographs: 7-9 Outlet Structures: 10-11 Reservoir: 12 Routed Hydrographs: 13-14 Westminster Canterbury Pond, SWM #2 Pre-Development: Flood Hydrographs: 15-17 Post-Development: Flood Hydrographs: 18-22 Outlet Structures: 23-25 Reservoir: 26-27 Routed Hydrographs: 28-29 Stormwater Management Pond #1 Pre-Development: Flood Hydrographs: 30-34 Post-Development: Flood Hydrographs: 35-42 Outlet Structures: 43-44 Reservoir: 45 Routed Hydrographs: 46-47 Uncontained Hydrographs: 48-50 Combined Hydrographs: 51-52 NOTE: DA Maps are part of the Luxor Stormwater Management Plans. Dominion Development Resources, LLC Page 2 (434)984-1599 Luxor Subdivision Summary Stormwater Management Facility #3 will provide water quality and volume control measures for portions of existing Westminster Canterbury and Ashcroft Subdivision currently handled by Stormwater Management Facility #2 and future residential and commercial areas. The BMP measures for this facility will consist of an aquatic bench, forebays, and extended detention. Stormwater Management Facility #2 was originally designed to provide water quality and volume control measures for Westminster Canterbury and Fontana. Post- construction, Facility #2 will provide water quality and volume control measures for Luxor Phase 1&2 and parts of the Fontana Subdivision in addition to receiving the routed flow from Facility #3. The existing emergency spillway for Facility #2 will be removed and a new emergency spillway shall be constructed that will allow for overland relief in a catastrophic event without impacting the adjacent existing and proposed residential areas. The BMP measures for this facility consist of forebays and extended detention. Stormwater Management Facility #1 will provide water quality and volume control measures for the North Pantops Commercial area, the Fontana Subdivision, and Phases 2 & 3 of the Luxor Subdivision. The construction of Facility #1 and the road network for Luxor Subdivison will consist of the removal of the existing Fontana Pond currently serving portions of the Fontana Subdivison. The area currently flowing to the Fontana Pond will be redirected to Facility #1. The BMP measures for this facility will consist of forebays, an aquatic bench, and extended detention. 1 • Dominion Development Resources, LLC Page 3 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 26.71 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 0.78 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Westminster (Undeveloped) 9.10 0.30 Ashcroft 3.30 0.40 Luxor Woods/Brush 14.30 0.30 Overall Approximation 26.70 0.31 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 17.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 0.90 (in) Return Period = 2 (yr) Storm Duration = 0.28 (hr) Dominion Development Resources, LLC Page 4 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 37.38 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 1.09 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Westminster (Undeveloped) 9.10 0.30 Ashcroft 3.30 0.40 Luxor Woods/Brush 14.30 0.30 Overall Approximation 26.70 0.31 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 17.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.26 (in) Return Period = User Defined (yr) Storm Duration = 0.28 (hr) Dominion Development Resources, LLC Page 5 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 53.73 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 1.57 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Westminster (Undeveloped) 9.10 0.30 Ashcroft 3.30 0.40 Luxor Woods/Brush 14.30 0.30 Overall Approximation 26.70 0.31 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 17.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.81 (in) Return Period = 100 (yr) Storm Duration = 0.28 (hr) Dominion Development Resources, LLC Page 6 (434)984-1599 Luxor Subdivision Stonnwater Management Facility#3 Post-Development Hydrograph Report Name: DA-3, Post 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 71.47 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.85 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavilions-II 22.30 0.54 Westminster 10.76 0.70 Ashcroft 3.30 0.40 Overall Approximation 36.36 0.57 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 0.85 (in) Return Period = 2 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources,LLC Page 7 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report Name: DA-3, Post l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 99.41 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.57 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavilions-II 22.30 0.54 Westminster 10.76 0.70 Ashcroft 3.30 0.40 Overall Approximation 36.36 0.57 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.18 (in) Return Period = User Defined (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 8 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 • Post-Development Hydrograph Report Name: DA-3, Post 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 142.43 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 3.68 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavilions-II 22.30 0.54 Westminster 10.76 0.70 Ashcroft 3.30 0.40 Overall Approximation 36.36 0.57 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.69 (in) Return Period = 100 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 9 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Outlet Structure Report Type : Stand Pipe Name : SWM #3 Riser RATING CURVE LIMIT Minimum Elevation = 480.00 (ft) Maximum Elevation = 496.00 (ft) Elevation Increment = 0.50 (ft) STAND PIPE INFORMATION ORIFICE INFORMATION Diameter = 4.00 (ft) Crest Length = 12.57 (ft) Effective Crest Length = 10.07 (ft) Orifice Coefficient = 0.60 Fractional Open Area = 0.83 OPTIONAL WEIR INFORMATION Type : Rectangular Weir Suppressed WEIR INFORMATION Crest Length = 2.50 (ft) Crest Elevation = 492.00 (ft) Weir Coefficient = 3.33 Exponential = 1.50 OPTIONAL ORIFICE INFORMATION Type : Circular Orifice OPTIONAL ORIFICE INFORMATION Diameter = 1.00 (ft) Invert Elevation = 490.00 (ft) Orifice Coefficient = 0.60 Number of Openings = 2 Dominion Development Resources, LLC Page 10 (434)984-1599 - Luxor Subdivision Stormwater Management Facility#3 Outlet Structure Report CULVERT INFORMATION Type : Circular Concrete - Square Edge with Headwall OUTLET STRUCTURE INFORMATION Diameter = 36.00 (in) Invert Elevation = 480.00 (ft) Pipe Length = 292.00 (ft) Slope = 0.08 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 468.40 (ft) Number of Barrels = 1 STAND PIPE STAGE VS. DISCHARGE Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 490.00 10.00 0.00 0.00 0.00 100.88 0.00 490.50 10.50 0.00 1.89 0.00 103.95 1.89 491.00 11.00 0.00 5.35 0.00 106.92 5.35 491.50 11.50 0.00 7.56 0.00 109.82 7.56 492.00 12.00 1.18 9.26 0.00 112.64 9.26 492.50 12.50 6.27 10.69 0.00 115.40 13.64 493.00 13.00 14.44 11.95 0.00 118.08 20.28 493.50 13.50 24.71 13.09 0.00 120.71 28.39 . 494.00 14.00 36.71 14.14 11.85 123.28 49.54 494.50 14.50 50.21 15.12 33.52 125.80 81.55 495.00 15.00 65.06 16.04 55.73 128.28 115.02 495.50 15.50 81.15 16.91 70.99 130.70 130.70 496.00 16.00 98.39 17.73 79.37 133.08 133.08 Dominion Development Resources,LLC Page 11 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Reservoir Report Reservoir Number: 3 Name: SWM Facility #3 RATING CURVE LIMIT Minimum Elevation = 480.00 (ft) Maximum Elevation = 496.00 (ft) Elevation Increment = 0.50 (ft) STAGE STORAGE INFORMATION Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 489.99 0.00 0.00 0.00 0.00 2 490.00 27952.00 13976.00 139.76 139.76 3 492.00 33606.00 30779.00 61558.00 61697.76 4 494.00 40817.00 37211.50 74423.00 136120.76 5 496.00 45510.00 43163.50 86327.00 222447.76 DISCHARGE INFORMATION Structure Number: 1 Type: Name: SWM #3 Riser RESERVOIR STAGE STORAGE/DISCHARGE Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 490.00 10.00 27952.00 6988.00 0.00 490.50 10.50 29365.50 21317.37 1.89 491.00 11.00 30779.00 36353.50 5.35 491.50 11.50 32192.50 52096.37 7.56 492.00 12.00 33606.00 68546.00 9.26 492.50 12.50 35408.75 85799.69 13.64 493.00 13.00 37211.50 103954.75 20.28 493.50 13.50 39014.25 123011.19 28.39 494.00 14.00 40817.00 142969.00 49.54 494.50 14.50 41990.25 163670.81 81.55 495.00 15.00 43163.50 184959.25 115.02 495.50 15.50 44336.75 206834.31 130.70 496.00 16.00 45510.00 229296.00 133.08 Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) Dominion Development Resources, LLC Page 12 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report Name: SWM3, 2yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 9.49 (cfs) Time to Peak (Tp) = 35.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 1.69 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 492.03 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-3, Post 2yr Peak Flow (Qp) = 71.47 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.85 (ac-ft) Flow Multiplier = 1.00 Name: SWM3, l0yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 16.87 (cfs) Time to Peak (Tp) = 34.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 2.41 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 492.74 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-3, Post l0yr Peak Flow (Qp) = 99.41 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.57 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources, LLC Page 13 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report Name: SWM3, 100yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 34.50 (cfs) Time to Peak (Tp) = 32.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 3.52 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 493.64 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 229296.00 (cu ft) Maximum Discharge = 133.08 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-3, Post 100yr Peak Flow (Qp) = 142.43 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 3.68 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources,LLC Page 14 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 77.46 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 4.00 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana Woods/Brush 38.20 0.30 Ashcroft 27.70 0.30 Westminster (from DA-3) 9.10 0.30 Luxor Woods/Brush 19.40 0.30 Ashcroft (from DA-3) 3.30 0.40 Luxor Woods/Brush (from DA-3) 14.30 0.30 Overall Approximation 112.00 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 30.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.13 (in) Return Period = 2 (yr) Storm Duration = 0.50 (hr) Dominion Development Resources, LLC Page 15 (434)984-1599 • Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 111.13 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 5.74 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana Woods/Brush 38.20 0.30 Ashcroft 27.70 0.30 Westminster (from DA-3) 9.10 0.30 Luxor Woods/Brush 19.40 0.30 Ashcroft (from DA-3) 3.30 0.40 Luxor Woods/Brush (from DA-3) 14.30 0.30 Overall Approximation 112.00 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 30.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.62 (in) Return Period = 10 (yr) Storm Duration = 0.50 (hr) Dominion Development Resources,LLC Page 16 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, 10Oyr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 161.99 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 8.37 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana Woods/Brush 38.20 0.30 Ashcroft 27.70 0.30 Westminster (from DA-3) 9.10 0.30 Luxor Woods/Brush 19.40 0.30 Ashcroft (from DA-3) 3.30 0.40 Luxor Woods/Brush (from DA-3) 14.30 0.30 Overall Approximation 112.00 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 30.00 (min) RAINFALL DESCRIPTION Total Precipitation = 2.37 (in) Return Period = 100 (yr) Storm Duration = 0.50 (hr) Dominion Development Resources, LLC Page 17 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 135.41 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 5.83 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana (1/2 acre Lots) 36.40 0.50 Pavilions-I 17.10 0.75 Woods/Brush 25.60 0.30 Pavilions-II 4.90 0.50 Undeveloped Pond Area 4.00 0.53 Commercial 11.25 0.85 Overall Approximation 99.25 0.53 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 25.00 (min) RAINFALL DESCRIPTION Distribution Type = Synthetic Total Precipitation = 1.06 (in) Return Period = 2 (yr) Storm Duration = 0.42 (hr) Dominion Development Resources, LLC Page 18 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow ((lp) = 192.80 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 8.30 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana (1/2 acre Lots) 36.40 0.50 Pavilions-I 17.10 0.75 Woods/Brush 25.60 0.30 Pavilions-II 4.90 0.50 Undeveloped Pond Area 4.00 0.53 Commercial 11.25 0.85 Overall Approximation 99.25 0.53 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 25.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.51 (in) Return Period = 10 (yr) Storm Duration = 0.42 (hr) Dominion Development Resources, LLC Page 19 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 279.88 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 12.05 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana (1/2 acre Lots) 36.40 0.50 Pavilions-I 17.10 0.75 Woods/Brush 25.60 0.30 Pavilions-II 4.90 0.50 Undeveloped Pond Area 4.00 0.53 Commercial 11.25 0.85 Overall Approximation 99.25 0.53 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 25.00 (min) RAINFALL DESCRIPTION Total Precipitation = 2.19 (in) Return Period = 100 (yr) Storm Duration = 0.42 (hr) Dominion Development Resources, LLC Page 20 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report Name: DA-2 & SWM3, 2yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 143.85 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 7.52 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: DA-2, Post 2yr Type: Modified Rational Peak Flow (Qp) = 135.41 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) Name: SWM3, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 9.49 (cfs) Time to Peak (Tp) = 35.00 (min) Time Step = 1.00 (min) Name: DA-2 & SWM3, l0yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 205.97 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 10.71 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: DA-2, Post l0yr Type: Modified Rational Peak Flow (Qp) = 192.80 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) Name: SWM3, 10yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 16.87 (cfs) Time to Peak (Tp) = 34.00 (min) Time Step = 1.00 (min) Dominion Development Resources,LLC Page 21 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report Name: DA-2 & SW43, 100yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 306.10 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 15.57 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: SWM3, 100yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 34.50 (cfs) Time to Peak (Tp) = 32.00 (min) Time Step = 1.00 (min) Name: DA-2, Post 100yr Type: Modified Rational Peak Flow (Qp) = 279.88 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) Dominion Development Resources, LLC Page 22 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report Type : Stand Pipe Name : SWM #2 Riser RATING CURVE LIMIT Minimum Elevation = 427.21 (ft) Maximum Elevation = 444.00 (ft) Elevation Increment = 0.25 (ft) STAND PIPE INFORMATION ORIFICE INFORMATION Diameter = 5.00 (ft) Crest Length = 15.71 (ft) Effective Crest Length = 15.71 (ft) Orifice Coefficient = 0.60 Fractional Open Area = 1.00 WEIR INFORMATION Crest Elevation = 434.84 (ft) Weir Coefficient = 3.33 Exponential = 1.50 Dominion Development Resources, LLC Page 23 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report SWM #2 Riser CULVERT INFORMATION Type : Circular Concrete - Square Edge with Headwall OUTLET STRUCTURE INFORMATION Culvert Diameter = 36.00 (in) Orifice Plate Diameter = 28.00 (in) Invert Elevation = 427.21 (ft) Pipe Length = 169.57 (ft) Slope = 0.03 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 424.14 (ft) Number of Barrels = 1 STAND PIPE STAGE VS. DISCHARGE Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 434.21 7.00 0.00 0.00 0.00 50.15 0.00 434.71 7.50 0.00 0.00 0.00 52.39 0.00 435.21 8.00 0.00 0.00 11.77 54.54 11.77 435.71 8.50 0.00 0.00 42.45 56.60 42.45 436.21 9.00 0.00 0.00 83.88 58.60 58.60 436.71 9.50 0.00 0.00 119.30 60.53 60.53 437.21 10.00 0.00 0.00 145.49 62.39 62.39 437.71 10.50 0.00 0.00 160.10 64.21 64.21 438.21 11.00 0.00 0.00 173.49 65.97 65.97 438.71 11.50 0.00 0.00 185.91 67.69 67.69 439.21 12.00 0.00 0.00 197.56 69.37 69.37 439.71 12.50 0.00 0.00 208.55 71.00 71.00 440.21 13.00 0.00 0.00 219.00 72.60 72.60 440.71 13.50 0.00 0.00 228.96 74.17 74.17 441.21 14.00 0.00 0.00 238.52 75.70 75.70 441.71 14.50 0.00 0.00 247.70 77.20 77.20 442.21 15.00 0.00 0.00 256.56 78.68 78.68 442.71 15.50 0.00 0.00 265.12 80.08 80.08 443.21 16.00 0.00 0.00 273.41 81.15 81.15 443.71 16.50 0.00 0.00 281.46 82.21 82.21 Dominion Development Resources, LLC Page 24 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report Type : Trapezoidal Weir Name : SWM #2 Overflow RATING CURVE LIMIT Minimum Elevation = 441.00 (ft) Maximum Elevation = 444.60 (ft) Elevation Increment = 0.20 (ft) OUTLET STRUCTURE INFORMATION Crest Length = 16.00 (ft) Angle of Walls = 33.3333 Crest Elevation = 441.00 (ft) Weir Coefficient = 3.33 Exponential = 1.50 MAXIMUM DISCHARGE Q = 383.54 (cfs) WEIR STAGE VS. DISCHARGE Elevation (ft) Stage (ft) Discharge (cfs) 441.00 0.00 0.00 441.20 0.20 4.78 441.40 0.40 13.56 441.60 0.60 24.98 441.80 0.80 38.58 442.00 1.00 54.08 442.20 1.20 71.30 442.40 1.40 90.11 442.60 1.60 110.41 442.80 1.80 132.14 443.00 2.00 155.21 443.20 2.20 179.58 443.40 2.40 205.22 443.60 2.60 232.06 443.80 2.80 260.10 444.00 3.00 289.28 444.20 3.20 319.60 444.40 3.40 351.03 444.60 3.60 383.54 Dominion Development Resources, LLC Page 25 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Reservoir Report Reservoir Number: 2 Name: SWM Facility #2 RATING CURVE LIMIT Minimum Elevation = 427.21 (ft) Maximum Elevation = 444.00 (ft) Elevation Increment = 0.20 (ft) STAGE STORAGE INFORMATION Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 434.84 0.00 0.00 0.00 0.00 2 434.85 57977.00 28988.50 144.94 144.94 3 436.00 71184.00 64580.50 74590.48 74735.42 4 438.00 78214.00 74699.00 149398.00 224133.42 5 440.00 85341.00 81777.50 163555.00 387688.42 6 442.00 95223.00 90282.00 180564.00 568252.42 7 444.00 106120.00 100671.50 201343.00 769595.42 DISCHARGE INFORMATION Structure Number: 1 Type: Name: SWM #2 Riser Structure Number: 2 Type: Trapezoidal Weir Name: SWM #2 Overflow RESERVOIR STAGE STORAGE/DISCHARGE Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 434.81 7.60 0.00 0.00 0.00 435.01 7.80 59863.71 5986.37 3.67 435.21 8.00 62150.64 18187.81 11.77 435.41 8.20 64437.57 30846.63 22.51 435.61 8.40 66724.49 43962.83 35.34 435.81 8.60 69011.42 57536.43 49.97 436.01 8.80 71219.15 71559.48 57.81 436.21 9.00 71922.15 85873.61 58.60 436.41 9.20 72625.15 100328.34 59.38 436.61 9.40 73328.15 114923.67 60.14 436.81 9.60 74031.15 129659.60 60.90 437.01 9.80 74734.15 144536.13 61.65 437.21 10.00 75437.15 159553.26 62.39 437.41 10.20 76140.15 174710.99 63.13 437.61 10.40 76843.15 190009.32 63.85 437.81 10.60 77546.15 205448.25 64.57 438.01 10.80 78249.63 221027.83 65.27 438.21 11.00 78962.33 236749.03 65.97 438.41 11.20 79675.03 252612.76 66.67 438.61 11.40 80387.73 268619.04 67.35 438.81 11.60 81100.44 284767.86 68.03 439.01 11.80 81813.13 301059.22 68.70 Dominion Development Resources,LLC Page 26 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Reservoir Report RESERVOIR STAGE STORAGE/DISCHARGE (Cont'd) Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 439.21 12.00 82525.83 317493.11 69.37 439.41 12.20 83238.53 334069.55 70.03 439.61 12.40 83951.23 350788.53 70.68 439.81 12.60 84663.94 367650.04 71.33 440.01 12.80 85390.41 384655.48 71.97 440.21 13.00 86378.61 401832.38 72.60 440.41 13.20 87366.81 419206.92 73.23 440.61 13.40 88355.01 436779.10 73.86 440.81 13.60 89343.21 454548.93 74.48 441.01 13.80 90331.41 472516.39 75.15 441.21 14.00 91319.61 490681.49 80.84 441.41 14.20 92307.81 509044.23 90.38 441.61 14.40 93296.01 527604.61 102.52 441.81 14.60 94284.21 546362.64 116.81 442.01 14.80 95277.48 565318.81 132.99 442.21 15.00 96367.18 584483.27 150.88 442.41 15.20 97456.88 603865.68 170.35 442.61 15.40 98546.58 623466.03 191.30 442.81 15.60 99636.29 643284.31 213.55 443.01 15.80 100725.98 663320.54 237.13 443.21 16.00 101815.68 683574.71 261.99 443.41 16.20 102905.38 704046.81 288.11 443.61 16.40 103995.08 724736.86 315.44 443.81 16.60 105084.79 745644.85 343.95 Maximum Storage = 765709.30 (cu ft) Maximum Discharge = 372.10 (cfs) Dominion Development Resources, LLC Page 27 (434)9841599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Name: SWM2, 2yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 61.11 (cfs) Time to Peak (Tp) = 48.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 7.52 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 436.87 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #2 Storage Type = User-Defined Area Maximum Storage = 765709.30 (cu ft) Maximum Discharge = 372.10 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-2 & SWM3, 2yr Peak Flow (Qp) = 143.85 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 7.52 (ac-ft) Flow Multiplier = 1.00 Name: SWM2, l0yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 65.70 (cfs) Time to Peak (Tp) = 52.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 10.71 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 438.13 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #2 Storage Type = User-Defined Area Maximum Storage = 765709.30 (cu ft) Maximum Discharge = 372.10 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-2 & SWM3, l0yr Peak Flow (Qp) = 205.97 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 10.71 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources, LLC Page 28 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Name: SWM2, 10Oyr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 72.43 (cfs) Time to Peak (Tp) = 55.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 15.57 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 440.15 (ft) RESERVOIR STRUCTURE INFORMATION Name = SWM Facility #2 Storage Type = User-Defined Area Maximum Storage = 765709.30 (cu ft) Maximum Discharge = 372.10 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-2 & SWM3, 100yr Peak Flow (Qp) = 306.10 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1440.00 (min) Volume = 15.57 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources, LLC Page 29 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-1, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 122.88 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 5.50 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana 2.50 0.30 Commercial 11.40 0.74 Montessori 5.40 0.50 Roads 1.00 0.90 Future Uncontained 46.30 0.31 Luxor Woods/Brush 40.40 0.30 Fontana Pond Woods/Brush 32.90 0.30 Overall Approximation 139.90 0.35 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 26.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.07 (in) Return Period = 2 (yr) Storm Duration = 0.43 (hr) Dominion Development Resources, LLC Page 30 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-1, l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 175.25 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 7.85 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana 2.50 0.30 Commercial 11.40 0.74 Montessori 5.40 0.50 Roads 1.00 0.90 Future Uncontained 46.30 0.31 Luxor Woods/Brush 40.40 0.30 Fontana Pond Woods/Brush 32.90 0.30 Overall Approximation 139.90 0.35 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 26.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.53 (in) Return Period = 10 (yr) Storm Duration = 0.43 (hr) Dominion Development Resources, LLC Page 31 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-1, 1O0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 254.63 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 11.40 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Fontana 2.50 0.30 Commercial 11.40 0.74 Montessori 5.40 0.50 Roads 1.00 0.90 Future Uncontained 46.30 0.31 Luxor Woods/Brush 40.40 0.30 Fontana Pond Woods/Brush 32.90 0.30 Overall Approximation 139.90 0.35 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 26.00 (min) RAINFALL DESCRIPTION Total Precipitation = 2.23 (in) Return Period = 100 (yr) Storm Duration = 0.43 (hr) Dominion Development Resources, LLC Page 32 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-Fontana, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 32.05 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 0.88 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Overall Approximation 32.85 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 16.00 (min) RAINFALL DESCRIPTION Total Precipitation = 0.86 (in) Return Period = 2 (yr) Storm Duration = 0.27 (hr) Name: DA-Fontana, l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 45.35 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 1.25 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area CN Runoff Coef Overall Approximation 32.85 NA 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 16.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.22 (in) Return Period = 10 (yr) Storm Duration = 0.27 (hr) Dominion Development Resources, LLC Page 33 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-Fontana, 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 65.68 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 1.81 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Overall Approximation 32.90 0.30 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 16.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.76 (in) Return Period = 100 (yr) Storm Duration = 0.27 (hr) Dominion Development Resources, LLC Page 34 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 78.93 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 2.72 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavilions-I 6.80 0.55 Commercial 23.35 0.84 Existing Fontana 2.20 0.50 Undeveloped 4.60 0.55 Overall Approximation 36.95 0.73 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 0.97 (in) Return Period = 2 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 35 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 111.28 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 3.83 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavlions-I 6.80 0.55 Commercial 23.35 0.84 Existing Fontana 2.20 0.50 Undeveloped 4.60 0.55 Overall Approximation 36.95 0.73 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.36 (in) Return Period = 10 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 36 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post 1O0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 160.65 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 5.53 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Pavilions-I 6.80 0.55 Commercial 23.35 0.84 Existing Fontana 2.20 0.50 Undeveloped 4.60 0.55 Overall Approximation 36.95 0.73 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.97 (in) Return Period = 100 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 37 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-Fontana Pond, 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 56.18 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.45 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef 1/2acre Lots 32.85 0.50 Overall Approximation 32.85 0.50 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Total Precipitation = 0.85 (in) Return Period = 2 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 38 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Post-Development Hydrograph Report Name: DA-Fontana Pond, l0yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 78.15 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.02 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef 1/2acre Lots 32.85 0.50 Overall Approximation 32.85 0.50 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.18 (in) Return Period = 10 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 39 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-Fontana Pond, 100yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 111.96 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.89 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef 1/2acre Lots 32.85 0.50 Overall Approximation 32.85 0.50 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 15.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.69 (in) Return Period = 100 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 40 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: DA-Fontana Pond & DA-1 & SWM2, 2yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 167.92 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1130.00 (min) Volume = 11.85 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: DA-Fontana Pond, 2yr Type: Modified Rational Peak Flow (Qp) = 56.18 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post 2yr Type: Modified Rational Peak Flow (Qp) = 78.93 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Name: SWM2, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 61.11 (cfs) Time to Peak (Tp) = 48.00 (min) Time Step = 1.00 (min) Name: DA-Fontana Pond & DA-1 & SWM2, l0yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 230.04 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1147.00 (min) Volume = 16.72 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: DA-Fontana Pond, l0yr Type: Modified Rational Peak Flow (Qp) = 78.15 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post l0yr Type: Modified Rational Peak Flow (Qp) = 111.28 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Name: SWM2, l0yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 65.70 (cfs) Time to Peak (Tp) = 52.00 (min) Time Step = 1.00 (min) Dominion Development Resources,LLC Page 41 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: DA-Fontana Pond & DA-1 & SWM2, 100yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 307.75 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1157.00 (min) Volume = 24.15 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: SWM2, 100yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 72.43 (cfs) Time to Peak (Tp) = 55.00 (min) Time Step = 1.00 (min) Name: DA-Fontana Pond, 100yr Type: Modified Rational Peak Flow (Qp) = 111.96 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post 100yr Type: Modified Rational Peak Flow (Qp) = 160.65 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Dominion Development Resources, LLC Page 42 (434)984-1599 Luxor Subdivision Stommwater Management Pond#1 Outlet Structure Report Structure Number : 1 Type : Stand Pipe Name : SWM #1 Riser RATING CURVE LIMIT Minimum Elevation = 402.00 (ft) Maximum Elevation = 422.00 (ft) Elevation Increment = 0.25 (ft) STAND PIPE INFORMATION ORIFICE INFORMATION Diameter = 6.00 (ft) Crest Length = 18.85 (ft) Effective Crest Length = 18.85 (ft) Orifice Coefficient = 0.70 Fractional Open Area = 0.83 WEIR INFORMATION Crest Elevation = 417.80 (ft) Weir Coefficient = 3.33 Exponential = 1.50 OPTIONAL ORIFICE INFORMATION Structure Number : 1 Type : Rectangular Orifice OPTIONAL ORIFICE INFORMATION Height = 1.75 (ft) Width = 2.00 (ft) Invert Elevation = 415.00 (ft) Orifice Coefficient = 0.60 Number of Openings = 4 Dominion Development Resources, LLC Page 43 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Outlet Structure Report SWM #1 Riser CULVERT INFORMATION Type : Circular Concrete - Square Edge with Headwall OUTLET STRUCTURE INFORMATION Diameter = 60.00 (in) Invert Elevation = 402.00 (ft) Pipe Length = 217.00 (ft) Slope = 0.03 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 0.00 (ft) Number of Barrels = 1 STAND PIPE STAGE VS. DISCHARGE Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 415.00 13.00 0.00 0.00 0.00 306.81 0.00 415.50 13.50 0.00 9.63 0.00 314.60 9.63 416.00 14.00 0.00 27.23 0.00 322.21 27.23 416.50 14.50 0.00 50.02 0.00 329.64 50.02 417.00 15.00 0.00 71.47 0.00 336.90 71.47 417.50 15.50 0.00 85.90 0.00 344.02 85.90 418.00 16.00 0.00 98.23 5.61 350.99 103.84 418.50 16.50 0.00 109.17 36.76 357.82 145.93 419.00 17.00 0.00 119.12 82.51 364.52 201.63 419.50 17.50 0.00 128.29 138.30 371.11 266.59 420.00 18.00 0.00 136.85 181.67 377.58 318.52 420.50 18.50 0.00 144.91 216.53 383.94 361.44 421.00 19.00 0.00 152.54 235.73 390.19 388.27 421.50 19.50 0.00 159.81 253.48 396.35 396.35 422.00 20.00 0.00 166.76 270.06 402.41 402.41 . Dominion Development Resources, LLC Page 44 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Reservoir Report Reservoir Number: 1 Name: SWM Facility #1 RATING CURVE LIMIT Minimum Elevation = 402.00 (ft) Maximum Elevation = 422.00 (ft) Elevation Increment = 0.25 (ft) STAGE STORAGE INFORMATION Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 415.00 0.00 0.00 0.00 0.00 2 415.10 72051.00 36025.50 3602.55 3602.55 3 416.00 77362.00 74706.50 67235.85 70838.40 4 418.00 89904.00 83633.00 167266.00 238104.40 5 420.00 105457.00 97680.50 195361.00 433465.40 6 422.00 118650.00 112053.50 224107.00 657572.40 DISCHARGE INFORMATION Structure Number: 1 Type: Name: SWM #1 Riser RESERVOIR STAGE STORAGE/DISCHARGE Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 415.00 13.00 0.00 0.00 0.00 415.50 13.50 74411.44 27535.47 9.63 416.00 14.00 77362.00 65478.83 27.23 416.50 14.50 80497.50 104943.71 50.02 417.00 15.00 83633.00 145976.33 71.47 417.50 15.50 86768.50 188576.71 85.90 418.00 16.00 89904.00 232744.83 103.84 418.50 16.50 93792.25 278668.90 145.93 419.00 17.00 97680.50 326537.08 201.63 419.50 17.50 101568.75 376349.40 266.59 420.00 18.00 105457.00 428105.83 318.52 420.50 18.50 108755.25 481658.90 361.44 421.00 19.00 112053.50 536861.08 388.27 421.50 19.50 115351.75 593712.40 396.35 422.00 20.00 118650.00 652212.83 402.41 Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 402.41 (cfs) Dominion Development Resources,LLC Page 45 (434)984-1599 Luxor Subdivision Stonnwater Management Pond#1 Routed Hydrograph Report Name: SWM1, 2yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 78.50 (cfs) Time to Peak (Tp) = 44.00 (min) Time of Base (Tb) = 1250.00 (min) Volume = 11.85 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 417.23 (ft) RESERVOIR STRUCTURE INFORMATION Number = 1 Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-Fontana Pond & DA-1 & SWM2, 2yr Peak Flow (Qp) = 167.92 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1130.00 (min) Volume = 11.85 (ac-ft) Flow Multiplier = 1.00 Name: SW MI1, l0yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 96.33 (cfs) Time to Peak (Tp) = 42.00 (min) Time of Base (Tb) = 1268.00 (min) Volume = 16.72 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 417.84 (ft) RESERVOIR STRUCTURE INFORMATION Number = 1 Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-Fontana Pond & DA-1 & SWM2, l0yr Peak Flow (Qp) = 230.04 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1147.00 (min) Volume = 16.72 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources, LLC Page 46 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Routed Hydrograph Report Name: SWM1, 100yr Type: Reservoir: Modified Puls HYDROGRAPH INFORMATION Peak Flow (Qp) = 148.97 (cfs) Time to Peak (Tp) = 36.00 (min) Time of Base (Tb) = 1281.00 (min) Volume = 24.15 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 418.53 (ft) RESERVOIR STRUCTURE INFORMATION Number = 1 Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) INFLOW HYDROGRAPH INFORMATION Name = DA-Fontana Pond & DA-1 & SWM2, 100yr Peak Flow (Qp) = 307.75 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1157.00 (min) Volume = 24.15 (ac-ft) Flow Multiplier = 1.00 Dominion Development Resources,LLC Page 47 (434)984-1599 Luxor Subdivision Stonnwater Management Pond #1 Uncontained Hydrograph Report Name: DA-1, Uncontained 2yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 54.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 1.86 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Impervious Areas 0.70 0.90 Unimproved Areas 18.00 0.30 Avemore & Unimproved Areas 22.20 0.30 Town & Country (Future) 4.00 0.70 Fontana 6.00 0.50 Overall Approximation 50.90 0.36 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 0.97 (in) Return Period = 2 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 4.8 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Uncontained Hydrograph Report Name: DA-1, Uncontained 10yr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 76.29 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 2.63 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Impervious Areas 0.70 0.90 Unimproved Areas 18.00 0.30 Avemore & Unimproved Areas 22.20 0.30 Town & Country (Future) 4.00 0.70 Fontana 6.00 0.50 Overall Approximation 50.90 0.36 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.36 (in) Return Period = 10 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources,LLC Page 49 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report Name: DA-1, Uncontained 1OOyr Type: Modified Rational HYDROGRAPH INFORMATION Peak Flow (Qp) = 110.14 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 3.79 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 RATIONAL HYDROGRAPH INFORMATION Flow Multiplier = 1.00 Receding Limb Factor = 1.50 WEIGHTED WATERSHED AREA Description Area Runoff Coef Impervious Areas 0.70 0.90 Unimproved Areas 18.00 0.30 Avemore & Unimproved Areas 22.20 0.30 Town & Country (Future) 4.00 0.70 Fontana 6.00 0.50 Overall Approximation 50.90 0.36 TIME CONCENTRATION -- User Defined Time of Concentration (Tc) = 20.00 (min) RAINFALL DESCRIPTION Total Precipitation = 1.97 (in) Return Period = 100 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 50 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Combined Hydrograph Report ' Name: SWM1 & DA-1 Uncontained, 2yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 107.94 (cfs) Time to Peak (Tp) = 28.00 (min) Time of Base (Tb) = 1250.00 (min) Volume = 13.71 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: SWM1, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 78.50 (cfs) Time to Peak (Tp) = 44.00 (min) Time Step = 1.00 (min) Name: DA-1, Uncontained 2yr Type: Modified Rational Peak Flow (Qp) = 54.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Name: SWM1 & DA-1 Uncontained, l0yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 142.72 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1268.00 (min) Volume = 19.35 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: SWM1, l0yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 96.33 (cfs) Time to Peak (Tp) = 42.00 (min) Time Step = 1.00 (min) Name: DA-1, Uncontained l0yr Type: Modified Rational Peak Flow (Qp) = 76.29 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Dominion Development Resources, LLC Page 51 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: SWM1 & DA-1 Uncontained, 100yr Type: Combined HYDROGRAPH INFORMATION Peak Flow (Qp) = 208.96 (cfs) Time to Peak (Tp) = 31.00 (min) Time of Base (Tb) = 1281.00 (min) Volume = 27.94 (ac-ft) Time Step = 1.00 (min) COMBINED HYDROGRAPH RECORDS Name: SWM1, 100yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 148.97 (cfs) Time to Peak (Tp) = 36.00 (min) Time Step = 1.00 (min) Name: DA-1, Uncontained 100yr Type: Modified Rational Peak Flow (Qp) = 110.14 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Dominion Development Resources, LLC Page 52 (434)984-1599 AMENDMENT TO HYDROLOGIC/HYDRAULIC CALCULATIONS FOR Luxor Subdivision & Road Networks May 19, 2006 Rev: September 25, 2006 ArAnewe c LOCATION: 10/9 /0(0 Tax Map 78 Parcels 12B Albemarle County, Virginia —305 PREPARED BY: �_dvk rHc 'Lj Dominion Development Resources, LLC c,a 172 S. Pantops Drive *0 9", �1�$ Charlottesville, VA 22911 AO V T�� HY RAY MILLER P: 434.979.8121 0402 030542 F: 434.979.1681 i MNIAL Run-off Summary Point of Pre-Dev Pre-Dev Pre-Dev Post - Post-Dev Post-Dev Analysis DA 2-Year 10-Year Dev Rtd. 2- Rtd. 10- DA Year Year Outfall 3 3 26.23 37.24 3 Post 12.50 20.89 Outfall 2 2 75.35 109.77 2 Post & 61.36 66.02 SWM#3 Outfall 1 1 120.98 175.31 Fontana 107.77 142.59 Pond, 1, & SWM2 Luxor Subdivision Index Index: 2 Summary: 3 Stormwater Management Pond #3 Pre-Development: Flood Hydrographs: 4-9 Post-Development: Flood Hydrographs: 10-15 Outlet Structures: 16-18 Reservoir: 19 Routed Hydrographs: 20-25 Westminster Canterbury Pond, SWM #2 Pre-Development: Flood Hydrographs: 26-31 Post-Development: Flood Hydrographs: 32-43 Outlet Structures: 44-46 Reservoir: 47-48 Routed Hydrographs: 49-54 Stormwater Management Pond #1 Pre-Development: Flood Hydrographs: 55-66 Post-Development: Flood Hydrographs: 67-84 Outlet Structures: 85-86 Reservoir: 87 Routed Hydrographs: 88-93 Uncontained Hydrographs: 91-99 Combined Hydrographs: 100-103 NOTE: DA Maps are part of the Luxor Stormwater Management Plans. Dominion Development Resources, LLC Page 2 (434)984-1599 Luxor Subdivision Summary Stormwater Management Facility #3 will provide water quality and volume control measures for portions of existing Westminster Canterbury and Ashcroft Subdivision currently handled by Stormwater Management Facility #2 and future residential and commercial areas. The BMP measures for this facility will consist of an aquatic bench, forebays, and extended detention. Stormwater Management Facility #2 is an existing stormwater management facility designed to provide water quality and volume control measures for Westminster Canterbury and Fontana. Post-construction, Facility #2 will provide water quality and volume control measures for Luxor Phase 1&2 and parts of the Fontana Subdivision in addition to receiving the routed flow from Facility #3. The existing emergency spillway for Facility #2 will be removed and a new emergency spillway shall be constructed that will allow for overland relief in a catastrophic event without impacting the adjacent existing and proposed residential areas. The BMP measures for this facility consist of forebays and extended detention. Stormwater Management Facility #1 will provide water quality and volume control measures for the North Pantops Commercial area, the Fontana Subdivision, and Phases 2 & 3 of the Luxor Subdivision. The construction of Facility #1 and the road network for Luxor Subdivison will consist of the removal of the existing Fontana Pond currently serving portions of the Fontana Subdivison. The area currently flowing to the Fontana Pond will be redirected to Facility #1. The BMP measures for this facility will consist of forebays, an aquatic bench, and extended detention. M Dominion Development Resources, LLC Page 3 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 26.23 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 0.77 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 0.77 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Westminster (Undeveloped) 9.10 0 0.30 Ashcroft 3.30 0 0.40 Woods/Brush 14.30 0 0.30 Overall Approximation 26.70 NA 0.31 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 17.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 0.88 (in) Return Period = 2 (yr) Storm Duration = 0.28 (hr) Dominion Development Resources, LLC Page 4 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report DA-3, 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.05 0.00 1.54 2 2.00 0.05 0.10 1.54 3.09 3 3.00 0.05 0.16 1.54 4.63 4 4.00 0.05 0.21 1.54 6.17 5 5.00 0.05 0.26 1.54 7.71 6 6.00 0.05 0.31 1.54 9.26 7 7.00 0.05 0.36 1.54 10.80 8 8.00 0.05 0.42 1.54 12.34 9 9.00 0.05 0.47 1.54 13.88 10 10.00 0.05 0.52 1.54 15.43 11 11.00 0.05 0.57 1.54 16.97 12 12.00 0.05 0.62 1.54 18.51 13 13.00 0.05 0.68 1.54 20.06 14 14.00 0.05 0.73 1.54 21.60 15 15.00 0.05 0.78 1.54 23.14 16 16.00 0.05 0.83 1.54 24.68 17 17.00 0.05 0.88 1.54 26.23 18 18.00 0.00 0.88 -1.03 25.20 19 19.00 0.00 0.88 -1.03 24.17 20 20.00 0.00 0.88 -1.03 23.14 21 21.00 0.00 0.88 -1.03 22.11 22 22.00 0.00 0.88 -1.03 21.08 23 23.00 0.00 0.88 -1.03 20.06 24 24.00 0.00 0.88 -1.03 19.03 25 25.00 0.00 0.88 -1.03 18.00 ` 26 26.00 0.00 0.88 -1.03 16.97 27 27.00 0.00 0.88 -1.03 15.94 28 28.00 0.00 0.88 -1.03 14.91 29 29.00 0.00 0.88 -1.03 13.88 30 30.00 0.00 0.88 -1.03 12.86 31 31.00 0.00 0.88 -1.03 11.83 32 32.00 0.00 0.88 -1.03 10.80 33 33.00 0.00 0.88 -1.03 9.77 34 34.00 0.00 0.88 -1.03 8.74 35 35.00 0.00 0.88 -1.03 7.71 36 36.00 0.00 0.88 -1.03 6.69 37 37.00 0.00 0.88 -1.03 5.66 38 38.00 0.00 0.88 -1.03 4.63 39 39.00 0.00 0.88 -1.03 3.60 40 40.00 0.00 0.88 -1.03 2.57 41 41.00 0.00 0.88 -1.03 1.54 42 42.00 0.00 0.88 -1.03 0.51 43 42.50 0.00 0.88 -0.51 0.00 Dominion Development Resources,LLC Page 5 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 37.24 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 1.09 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.09 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Westminster (Undeveloped) 9.10 0 0.30 Ashcroft 3.30 0 0.40 Woods/Brush 14.30 0 0.30 Overall Approximation 26.70 NA 0.31 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 17.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.25 (in) Return Period = User Defined (yr) Storm Duration = 0.28 (hr) Dominion Development Resources,LLC Page 6 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report DA-3, l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.07 0.00 2.19 2 2.00 0.07 0.15 2.19 4.38 3 3.00 0.07 0.22 2.19 6.57 4 4.00 0.07 0.30 2.19 8.76 5 5.00 0.07 0.37 2.19 10.95 6 6.00 0.07 0.44 2.19 13.14 7 7.00 0.07 0.52 2.19 15.33 8 8.00 0.07 0.59 2.19 17.52 9 9.00 0.07 0.66 2.19 19.71 10 10.00 0.07 0.74 2.19 21.90 11 11.00 0.07 0.81 2.19 24.10 12 12.00 0.07 0.89 2.19 26.29 13 13.00 0.07 0.96 2.19 28.48 14 14.00 0.07 1.03 2.19 30.67 15 15.00 0.07 1.11 2.19 32.86 16 16.00 0.07 1.18 2.19 35.05 17 17.00 0.07 1.25 2.19 37.24 18 18.00 0.00 1.25 -1.46 35.78 19 19.00 0.00 1.25 -1.46 34.32 20 20.00 0.00 1.25 -1.46 32.86 21 21.00 0.00 1.25 -1.46 31.40 22 22.00 0.00 1.25 -1.46 29.94 23 23.00 0.00 1.25 -1.46 28.48 24 24.00 0.00 1.25 -1.46 27.02 25 25.00 0.00 1.25 -1.46 25.56 26 26.00 0.00 1.25 -1.46 24.10 27 27.00 0.00 1.25 -1.46 22.63 28 28.00 0.00 1.25 -1.46 21.17 29 29.00 0.00 1.25 -1.46 19.71 30 30.00 0.00 1.25 -1.46 18.25 31 31.00 0.00 1.25 -1.46 16.79 32 32.00 0.00 1.25 -1.46 15.33 33 33.00 0.00 1.25 -1.46 13.87 34 34.00 0.00 1.25 -1.46 12.41 35 35.00 0.00 1.25 -1.46 10.95 36 36.00 0.00 1.25 -1.46 9.49 37 37.00 0.00 1.25 -1.46 8.03 38 38.00 0.00 1.25 -1.46 6.57 39 39.00 0.00 1.25 -1.46 5.11 40 40.00 0.00 1.25 -1.46 3.65 41 41.00 0.00 1.25 -1.46 2.19 42 42.00 0.00 1.25 -1.46 0.73 43 42.50 0.00 1.25 -0.73 0.00 Dominion Development Resources,LLC Page 7 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report Name: DA-3, 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 53.96 (cfs) Time to Peak (Tp) = 17.00 (min) Time of Base (Tb) = 42.50 (min) Volume = 1.58 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.58 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Westminster (Undeveloped) 9.10 0 0.30 Ashcroft 3.30 0 0.40 Woods/Brush 14.30 0 0.30 Overall Approximation 26.70 NA 0.31 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 17.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.82 (in) Return Period = 100 (yr) Storm Duration = 0.28 (hr) Dominion Development Resources, LLC Page 8 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Pre-Development Hydrograph Report DA-3, 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.11 0.00 3.17 2 2.00 0.11 0.21 3.17 6.35 3 3.00 0.11 0.32 3.17 9.52 4 4.00 0.11 0.43 3.17 12.70 5 5.00 0.11 0.53 3.17 15.87 6 6.00 0.11 0.64 3.17 19.04 7 7.00 0.11 0.75 3.17 22.22 8 8.00 0.11 0.86 3.17 25.39 9 9.00 0.11 0.96 3.17 28.57 10 10.00 0.11 1.07 3.17 31.74 11 11.00 0.11 1.18 3.17 34.91 12 12.00 0.11 1.28 3.17 38.09 13 13.00 0.11 1.39 3.17 41.26 14 14.00 0.11 1.50 3.17 44.44 15 15.00 0.11 1.60 3.17 47.61 16 16.00 0.11 1.71 3.17 50.78 17 17.00 0.11 1.82 3.17 53.96 18 18.00 0.00 1.82 -2.12 51.84 19 19.00 0.00 1.82 -2.12 49.73 20 20.00 0.00 1.82 -2.12 47.61 21 21.00 0.00 1.82 -2.12 45.49 22 22.00 0.00 1.82 -2.12 43.38 23 23.00 0.00 1.82 -2.12 41.26 24 24.00 0.00 1.82 -2.12 39.15 25 25.00 0.00 1.82 -2.12 37.03 26 26.00 0.00 1.82 -2.12 34.91 27 27.00 0.00 1.82 -2.12 32.80 28 28.00 0.00 1.82 -2.12 30.68 29 29.00 0.00 1.82 -2.12 28.57 30 30.00 0.00 1.82 -2.12 26.45 31 31.00 0.00 1.82 -2.12 24.33 32 32.00 0.00 1.82 -2.12 22.22 33 33.00 0.00 1.82 -2.12 20.10 34 34.00 0.00 1.82 -2.12 17.99 35 35.00 0.00 1.82 -2.12 15.87 36 36.00 0.00 1.82 -2.12 13.75 37 37.00 0.00 1.82 -2.12 11.64 38 38.00 0.00 1.82 -2.12 9.52 39 39.00 0.00 1.82 -2.12 7.41 40 40.00 0.00 1.82 -2.12 5.29 41 41.00 0.00 1.82 -2.12 3.17 42 42.00 0.00 1.82 -2.12 1.06 43 42.50 0.00 1.82 -1.06 0.00 Dominion Development Resources, LLC Page 9 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report Name: DA-3, Post 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 67.06 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.73 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.73 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavilions-II 21.10 0 0.54 Westminster 10.60 0 0.65 Ashcroft 3.30 0 0.40 Overall Approximation 35.00 NA 0.56 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 0.85 (in) Return Period = 2 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 10 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report DA-3, Post 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.06 0.00 4.47 2 2.00 0.06 0.11 4.47 8.94 3 3.00 0.06 0.17 4.47 13.41 4 4.00 0.06 0.23 4.47 17.88 5 5.00 0.06 0.28 4.47 22.35 6 6.00 0.06 0.34 4.47 26.82 7 7.00 0.06 0.40 4.47 31.29 8 8.00 0.06 0.45 4.47 35.76 9 9.00 0.06 0.51 4.47 40.23 10 10.00 0.06 0.57 4.47 44.71 11 11.00 0.06 0.62 4.47 49.18 12 12.00 0.06 0.68 4.47 53.65 13 13.00 0.06 0.74 4.47 58.12 14 14.00 0.06 0.79 4.47 62.59 15 15.00 0.06 0.85 4.47 67.06 16 16.00 0.00 0.85 -2.98 64.08 17 17.00 0.00 0.85 -2.98 61.10 18 18.00 0.00 0.85 -2.98 58.12 19 19.00 0.00 0.85 -2.98 55.14 20 20.00 0.00 0.85 -2.98 52.16 21 21.00 0.00 0.85 -2.98 49.18 22 22.00 0.00 0.85 -2.98 46.20 23 23.00 0.00 0.85 -2.98 43.21 24 24.00 0.00 0.85 -2.98 40.23 25 25.00 0.00 0.85 -2.98 37.25 ' 26 26.00 0.00 0.85 -2.98 34.27 27 27.00 0.00 0.85 -2.98 31.29 28 28.00 0.00 0.85 -2.98 28.31 29 29.00 0.00 0.85 -2.98 25.33 30 30.00 0.00 0.85 -2.98 22.35 31 31.00 0.00 0.85 -2.98 19.37 32 32.00 0.00 0.85 -2.98 16.39 33 33.00 0.00 0.85 -2.98 13.41 34 34.00 0.00 0.85 -2.98 10.43 35 35.00 0.00 0.85 -2.98 7.45 36 36.00 0.00 0.85 -2.98 4.47 37 37.00 0.00 0.85 -2.98 1.49 38 37.50 0.00 0.85 -1.49 0.00 Dominion Development Resources,LLC Page 11 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report Name: DA-3, Post l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 93.27 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.41 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 2.41 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavilions-II 21.10 0 0.54 Westminster 10.60 0 0.65 Ashcroft 3.30 0 0.40 Overall Approximation 35.00 NA 0.56 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.18 (in) Return Period = 10 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources,LLC Page 12 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report DA-3, Post l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.08 0.00 6.22 2 2.00 0.08 0.16 6.22 12.44 3 3.00 0.08 0.24 6.22 18.65 4 4.00 0.08 0.31 6.22 24.87 5 5.00 0.08 0.39 6.22 31.09 6 6.00 0.08 0.47 6.22 37.31 7 7.00 0.08 0.55 6.22 43.53 8 8.00 0.08 0.63 6.22 49.75 9 9.00 0.08 0.71 6.22 55.96 10 10.00 0.08 0.79 6.22 62.18 11 11.00 0.08 0.87 6.22 68.40 12 12.00 0.08 0.94 6.22 74.62 13 13.00 0.08 1.02 6.22 80.84 14 14.00 0.08 1.10 6.22 87.06 15 15.00 0.08 1.18 6.22 93.27 16 16.00 0.00 1.18 -4.15 89.13 17 17.00 0.00 1.18 -4.15 84.98 18 18.00 0.00 1.18 -4.15 80.84 19 19.00 0.00 1.18 -4.15 76.69 20 20.00 0.00 1.18 -4.15 72.55 21 21.00 0.00 1.18 -4.15 68.40 22 22.00 0.00 1.18 -4.15 64.26 23 23.00 0.00 1.18 -4.15 60.11 24 24.00 0.00 1.18 -4.15 55.96 25 25.00 0.00 1.18 -4.15 51.82 26 26.00 0.00 1.18 -4.15 47.67 27 27.00 0.00 1.18 -4.15 43.53 28 28.00 0.00 1.18 -4.15 39.38 29 29.00 0.00 1.18 -4.15 35.24 30 30.00 0.00 1.18 -4.15 31.09 31 31.00 0.00 1.18 -4.15 26.95 32 32.00 0.00 1.18 -4.15 22.80 33 33.00 0.00 1.18 -4.15 18.65 34 34.00 0.00 1.18 -4.15 14.51 35 35.00 0.00 1.18 -4.15 10.36 36 36.00 0.00 1.18 -4.15 6.22 37 37.00 0.00 1.18 -4.15 2.07 38 37.50 0.00 1.18 -2.07 0.00 Dominion Development Resources, LLC Page 13 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report Name: DA-3, Post 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 133.63 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 3.45 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 3.45 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavilions-II 21.10 0 0.54 Westminster 10.60 0 0.65 Ashcroft 3.30 0 0.40 Overall Approximation 35.00 NA 0.56 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.69 (in) Return Period = 100 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 14 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Post-Development Hydrograph Report DA-3, Post 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.11 0.00 8.91 2 2.00 0.11 0.23 8.91 17.82 3 3.00 0.11 0.34 8.91 26.73 4 4.00 0.11 0.45 8.91 35.64 5 5.00 0.11 0.56 8.91 44.54 6 6.00 0.11 0.68 8.91 53.45 7 7.00 0.11 0.79 8.91 62.36 8 8.00 0.11 0.90 8.91 71.27 9 9.00 0.11 1.01 8.91 80.18 10 10.00 0.11 1.13 8.91 89.09 11 11.00 0.11 1.24 8.91 98.00 12 12.00 0.11 1.35 8.91 106.91 13 13.00 0.11 1.46 8.91 115.82 14 14.00 0.11 1.58 8.91 124.73 15 15.00 0.11 1.69 8.91 133.63 16 16.00 0.00 1.69 -5.94 127.69 17 17.00 0.00 1.69 -5.94 121.76 18 18.00 0.00 1.69 -5.94 115.82 19 19.00 0.00 1.69 -5.94 109.88 20 20.00 0.00 1.69 -5.94 103.94 21 21.00 0.00 1.69 -5.94 98.00 22 22.00 0.00 1.69 -5.94 92.06 23 23.00 0.00 1.69 -5.94 86.12 24 24.00 0.00 1.69 -5.94 80.18 25 25.00 0.00 1.69 -5.94 74.24 26 26.00 0.00 1.69 -5.94 68.30 27 27.00 0.00 1.69 -5.94 62.36 28 28.00 0.00 1.69 -5.94 56.42 29 29.00 0.00 1.69 -5.94 50.48 30 30.00 0.00 1.69 -5.94 44.54 31 31.00 0.00 1.69 -5.94 38.61 32 32.00 0.00 1.69 -5.94 32.67 33 33.00 0.00 1.69 -5.94 26.73 34 34.00 0.00 1.69 -5.94 20.79 35 35.00 0.00 1.69 -5.94 14.85 36 36.00 0.00 1.69 -5.94 8.91 37 37.00 0.00 1.69 -5.94 2.97 38 37.50 0.00 1.69 -2.97 0.00 . Dominion Development Resources,LLC Page 15 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Outlet Structure Report Type : Stand Pipe Name : SWM #3 Riser [RATING CURVE LIMIT] Minimum Elevation = 480.00 (ft) Maximum Elevation = 492.00 (ft) Elevation Increment = 0.50 (ft) [STAND PIPE INFORMATION] [ORIFICE INFORMATION] Diameter = 4.00 (ft) Crest Length = 12.57 (ft) Effective Crest Length = 10.07 (ft) Orifice Coefficient = 0.60 Fractional Open Area = 0.83 [ORIFICE EQUATION] Q = Co*A( (2gh)/k)"0.5 [DEFINITIONS] Co = Orifice Coefficient A = Wetted Area, (sq ft) [WEIR INFORMATION] Crest Elevation = 491.50 (ft) Weir Coefficient = 3.33 Exponential = 1.50 [WEIR EQUATION] Q = Cw * L * H"exp [DEFINITIONS] Cw = Weir Coefficient H = Headwater depth above inlet control section invert ft L = Crest lenght ft [WEIR INFORMATION] Structure Number : 1 Type : Rectangular Weir Suppressed [WEIR INFORMATION] Crest Length = 2.50 (ft) Crest Elevation = 490.00 (ft) Weir Coefficient = 3.33 Exponential = 1.50 [RECTANGULAR SUPRESSED EQUATION] Q = Cw * L * H"exp [DEFINITIONS] Cw = Weir Coefficient H = Headwater depth above inlet control section invert L = Crest length . Dominion Development Resources, LLC Page 16 (434)984-1599 i. . Luxor Subdivision Stormwater Management Facility#3 Outlet Structure Report SWM #3 Riser [ORIFICE INFORMATION] Structure Number : 1 Type : Circular Orifice [OPTIONAL ORIFICE INFORMATION] Diameter = 1.00 (ft) Invert Elevation = 488.00 (ft) Orifice Coefficient = 0.60 Number of Openings = 2 [ORIFICE EQUATION] Q = Co*A((2gh)/k)A0.5 [DEFINITIONS] Co = Orifice Coefficient A = Wetted Area, (cfs) k = 1 [CULVERT INFORMATION] Type : Circular Concrete - Square Edge with Headwall [OUTLET STRUCTURE INFORMATION] Diameter = 36.00 (in) Invert Elevation = 480.00 (ft) Pipe Length = 179.00 (ft) Slope = 0.08 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 468.40 (ft) Number of Barrels = 1 [UNSUBMERGED EQUATION] H/Diam = Hc/Diam+K*(Q/(A*Diam'0.5) )"M-0.5*S Coefficient K = 0.01 Coefficient M = 2.00 Q Maximum = 42.85 [SUBMERGED EQUATION] H/Diam = c*(Q/(A*Diam^0.5) )'2+Y-0.5*S Coefficient c = 0.04 Coefficient Y = 0.67 Q Minimum = 48.97 [DEFINITIONS] H = Headwater depth above inlet control section invert, (ft) Diam = Interior height of culvert barrel, (ft) He = Specific head at critical depth (dc+Ve2/2g) , (ft) Q = Discharge, (cfs) A = Full cross sectional area of culvert barrel, (sq ft) S = Culvert barrel slope, (ft/ft) Dominion Development Resources, LLC Page 17 (434)984-1599 . Luxor Subdivision Stormwater Management Facility#3 • Outlet Structure Report SWM #3 Riser [STAND PIPE STAGE VS. DISCHARGE] Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 488.00 8.00 0.00 0.00 0.00 87.56 0.00 488.50 8.50 0.00 1.89 0.00 91.07 1.89 489.00 9.00 0.00 5.35 0.00 94.46 5.35 489.50 9.50 0.00 7.56 0.00 97.72 7.56 490.00 10.00 0.00 9.26 0.00 100.88 9.26 490.50 10.50 2.94 10.69 0.00 103.95 13.64 491.00 11.00 8.32 11.95 0.00 106.92 20.28 491.50 11.50 15.29 13.09 0.00 109.82 28.39 492.00 12.00 24.72 14.14 11.85 112.64 49.54 11 4 0 Dominion Development Resources, LLC Page 18 (434)984-1599 • Luxor Subdivision Stormwater Management Facility#3 Reservoir Report Name: SWM Facility #3 [RATING CURVE LIMIT] Minimum Elevation = 480.00 (ft) Maximum Elevation = 496.00 (ft) Elevation Increment = 0.50 (ft) [STAGE STORAGE INFORMATION] Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 488.00 0.00 0.00 0.00 0.00 2 488.01 24363.00 12181.50 60.91 60.91 3 490.00 30597.00 27480.00 54822.60 54883.51 4 492.00 36748.00 33672.50 67345.00 122228.51 5 494.00 44802.00 40775.00 81550.00 203778.51 6 496.00 51306.00 48054.00 96108.00 299886.51 [DISCHARGE INFORMATION] Structure Number: 1 Type: Name: SWM #3 Riser [RESERVOIR STAGE STORAGE/DISCHARGE] Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 488.00 8.00 0.00 0.00 0.00 488.50 8.50 25909.78 6477.45 1.89 489.00 9.00 27472.19 19822.94 5.35 489.50 9.50 29034.59 33949.63 7.56 490.00 10.00 30597.00 48857.53 9.26 490.50 10.50 32134.75 64540.47 13.64 491.00 11.00 33672.50 80992.28 20.28 491.50 11.50 35210.25 98212.97 28.39 492.00 12.00 36748.00 116202.53 49.54 492.50 12.50 38761.50 135079.91 81.55 493.00 13.00 40775.00 154964.03 115.02 493.50 13.50 42788.50 175854.91 120.71 494.00 14.00 44802.00 197752.53 123.28 494.50 14.50 46428.00 220560.03 125.80 495.00 15.00 48054.00 244180.53 128.28 495.50 15.50 49680.00 268614.03 130.70 496.00 16.00 51306.00 293860.53 133.08 Maximum Storage = 293860.53 (cu ft) Maximum Discharge = 133.08 (cfs) Dominion Development Resources, LLC Page 19 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report Name: SWM3, 2yr Type: Reservoir: Modified Puls [[HYDROGRAPH INFORMATION] Peak Flow (Qp) = 12.50 (cfs) Time to Peak (Tp) = 33.00 (min) Time of Base (Tb) = 1275.00 (min) Volume = 1.73 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 490.37 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 293860.53 (cu ft) Maximum Discharge = 133.08 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-3, Post 2yr Peak Flow (Qp) = 67.06 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.73 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (11+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: Il = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 4.47 4.47 0.00 265.86 0.04 132.95 488.01 2 2.00 8.94 13.41 265.86 1058.84 0.15 529.50 488.04 3 3.00 13.41 22.35 1058.84 2369.78 0.35 1185.06 488.09 4 4.00 17.88 31.29 2369.78 4189.70 0.61 2095.16 488.16 5 5.00 22.35 40.23 4189.70 6509.76 0.95 3255.36 488.25 6 6.00 26.82 49.18 6509.76 9321.28 1.36 4661.32 488.36 7 7.00 31.29 58.12 9321.28 12615.74 1.84 6308.79 488.49 8 8.00 35.76 67.06 12615.74 16388.15 2.33 8195.24 488.56 9 9.00 40.23 76.00 16388.15 20634.34 2.88 10318.61 488.64 10 10.00 44.71 84.94 20634.34 25347.31 3.50 12675.40 488.73 Dominion Development Resources, LLC Page 20 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report SWM3, 2yr Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (Cu ft) (ft) 11 11.00 49.18 93.88 25347.31 30519.88 4.16 15262.02 488.83 12 12.00 53.65 102.82 30519.88 36144.96 4.89 18074.93 488.93 13 13.00 58.12 111.76 36144.96 42223.56 5.55 21114.56 489.05 14 14.00 62.59 120.70 42223.56 48768.68 6.06 24387.37 489.16 15 15.00 67.06 129.64 48768.68 55786.44 6.61 27896.52 489.29 16 16.00 64.08 131.13 55786.44 62827.48 7.16 31417.32 489.41 17 17.00 61.10 125.17 62827.48 69448.70 7.65 34728.18 489.53 18 18.00 58.12 119.21 69448.70 75662.03 8.00 37835.02 489.63 19 19.00 55.14 113.25 75662.03 81476.61 8.33 40742.47 489.73 20 20.00 52.16 107.29 81476.61 86895.15 8.64 43451.90 489.82 21 21.00 49.18 101.33 86895.15 91920.37 8.93 45964.65 489.90 22 22.00 46.20 95.37 91920.37 96554.94 9.19 48282.07 489.98 23 23.00 43.21 89.41 96554.94 100786.07 9.69 50397.88 490.05 24 24.00 40.23 83.45 100786.07 104597.88 10.22 52304.05 490.11 25 25.00 37.25 77.49 104597.88 107991.80 10.69 54001.25 490.16 26 26.00 34.27 71.53 107991.80 110974.74 11.11 55492.92 490.21 27 27.00 31.29 65.57 110974.74 113553.54 11.47 56782.50 490.25 28 28.00 28.31 59.61 113553.54 115734.90 11.77 57873.34 490.29 29 29.00 25.33 53.65 115734.90 117525.43 12.02 58768.73 490.32 30 30.00 22.35 47.69 117525.43 118931.61 12.22 59471.91 490.34 31 31.00 19.37 41.72 118931.61 119959.82 12.36 59986.09 490.35 32 32.00 16.39 35.76 119959.82 120616.34 12.46 60314.40 490.37 33 33.00 13.41 29.80 120616.34 120907.33 12.50 60459.91 490.37 y 34 34.00 10.43 23.84 120907.33 120838.88 12.49 60425.68 490.37 35 35.00 7.45 17.88 120838.88 120416.93 12.43 60214.68 490.36 36 36.00 4.47 11.92 120416.93 119647.37 12.32 59829.85 490.35 37 37.00 1.49 5.96 119647.37 118535.97 12.17 59274.07 490.33 38 38.00 0.00 1.49 118535.97 117177.05 11.98 58594.51 490.31 39 39.00 0.00 0.00 117177.05 115752.03 11.78 57881.90 490.29 40 40.00 0.00 0.00 115752.03 114350.68 11.58 57181.13 490.27 41 41.00 0.00 0.00 114350.68 112972.58 11.39 56491.99 490.24 42 42.00 0.00 0.00 112972.58 111617.37 11.20 55814.29 490.22 43 43.00 0.00 0.00 111617.37 110284.66 11.01 55147.84 490.20 44 44.00 0.00 0.00 110284.66 108974.07 10.83 54492.45 490.18 45 45.00 0.00 0.00 108974.07 107685.24 10.65 53847.94 490.16 46 46.00 0.00 0.00 107685.24 106417.80 10.47 53214.14 490.14 47 47.00 0.00 0.00 106417.80 105171.41 10.30 52590.86 490.12 48 48.00 0.00 0.00 105171.41 103945.71 10.13 51977.92 490.10 49 49.00 0.00 0.00 103945.71 102740.36 9.96 51375.16 490.08 50 50.00 0.00 0.00 102740.36 101555.03 9.80 50782.41 490.06 51 51.00 0.00 0.00 101555.03 100389.37 9.63 50199.50 490.04 52 52.00 0.00 0.00 100389.37 99243.06 9.47 49626.27 490.02 53 53.00 0.00 0.00 99243.06 98115.78 9.32 49062.55 490.01 54 54.00 0.00 0.00 98115.78 97003.71 9.22 48506.47 489.99 55 55.00 0.00 0.00 97003.71 95901.22 9.16 47955.19 489.97 56 56.00 0.00 0.00 95901.22 94806.23 9.09 47407.66 489.95 57 57.00 0.00 0.00 94806.23 93718.71 9.03 46863.87 489.93 58 58.00 0.00 0.00 93718.71 92638.60 8.97 46323.79 489.92 59 59.00 0.00 0.00 92638.60 91565.85 8.91 45787.38 489.90 60 60.00 0.00 0.00 91565.85 90500.41 8.85 45254.63 489.88 61 61.00 0.00 0.00 90500.41 89442.24 8.79 44725.51 489.86 62 62.00 0.00 0.00 89442.24 88391.27 8.73 44200.00 489.84 63 63.00 0.00 0.00 88391.27 87347.47 8.67 43678.07 489.83 64 64.00 0.00 0.00 87347.47 86310.78 8.61 43159.70 489.81 65 65.00 0.00 0.00 86310.78 85281.16 8.55 42644.85 489.79 Dominion Development Resources, LLC Page 21 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report Name: SWM3, l0yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 20.89 (cfs) Time to Peak (Tp) = 32.00 (min) Time of Base (Tb) = 1297.00 (min) Volume = 2.41 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 491.04 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 293860.53 (cu ft) Maximum Discharge = 133.08 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-3, Post l0yr Peak Flow (Qp) = 93.27 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.41 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+12) + (2(S1)/dt)-Ol = (2(S2)/dt)+02 Where: I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 6.22 6.22 0.00 369.81 0.05 184.93 488.01 2 2.00 12.44 18.65 369.81 1472.81 0.21 736.51 488.06 3 3.00 18.65 31.09 1472.81 3296.29 0.48 1648.38 488.13 4 4.00 24.87 43.53 3296.29 5827.73 0.85 2914.29 488.22 5 5.00 31.09 55.96 5827.73 9054.85 1.32 4528.09 488.35 6 6.00 37.31 68.40 9054.85 12965.59 1.89 6483.74 488.50 7 7.00 43.53 80.84 12965.59 17552.64 2.49 8777.57 488.59 8 8.00 49.75 93.27 17552.64 22809.32 3.17 11406.25 488.68 9 9.00 55.96 105.71 22809.32 28725.31 3.93 14364.62 488.80 10 10.00 62.18 118.15 28725.31 35290.44 4.78 17647.61 488.92 11 11.00 68.40 130.58 35290.44 42503.55 5.57 21254.56 489.05 Dominion Development Resources, LLC Page 22 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report SWM3, l0yr Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 12 12.00 74.62 143.02 42503.55 50378.74 6.19 25192.46 489.19 13 13.00 80.84 155.46 50378.74 58922.85 6.86 29464.85 489.34 14 14.00 87.06 167.89 58922.85 68129.94 7.57 34068.76 489.50 15 15.00 93.27 180.33 68129.94 78006.61 8.14 39007.37 489.67 16 16.00 89.13 182.40 78006.61 87939.91 8.70 43974.30 489.84 17 17.00 84.98 174.11 87939.91 97309.76 9.24 48659.50 489.99 18 18.00 80.84 165.82 97309.76 106078.02 10.43 53044.22 490.13 19 19.00 76.69 157.53 106078.02 114209.34 11.56 57110.45 490.26 20 20.00 72.55 149.24 114209.34 121712.41 12.61 60862.51 490.38 21 21.00 68.40 140.95 121712.41 128597.64 13.57 64305.60 490.49 22 22.00 64.26 132.66 128597.64 134853.45 14.80 67434.12 490.59 23 23.00 60.11 124.37 134853.45 140469.79 15.94 70242.86 490.67 24 24.00 55.96 116.08 140469.79 145460.27 16.95 72738.61 490.75 25 25.00 51.82 107.78 145460.27 149839.87 17.83 74928.85 490.82 26 26.00 47.67 99.49 149839.87 153623.21 18.59 76820.90 490.87 27 27.00 43.53 91.20 153623.21 156824.57 19.24 78421.90 490.92 28 28.00 39.38 82.91 156824.57 159457.87 19.77 79738.82 490.96 29 29.00 35.24 74.62 159457.87 161536.73 20.19 80778.46 490.99 30 30.00 31.09 66.33 161536.73 163072.16 20.54 81546.35 491.02 31 31.00 26.95 58.04 163072.16 164075.23 20.78 82048.00 491.03 32 32.00 22.80 49.75 164075.23 164559.93 20.89 82290.41 491.04 33 33.00 18.65 41.46 164559.93 164540.71 20.89 82280.80 491.04 34 34.00 14.51 33.16 164540.71 164031.60 20.77 82026.18 491.03 35 35.00 10.36 24.87 164031.60 163046.26 20.53 81533.40 491.02 36 36.00 6.22 16.58 163046.26 161597.21 20.20 80808.71 490.99 37 37.00 2.07 8.29 161597.21 159693.56 19.82 79856.69 490.97 38 38.00 0.00 2.07 159693.56 157466.92 19.37 78743.15 490.93 • 39 39.00 0.00 0.00 157466.92 155170.73 18.91 77594.82 490.90 40 40.00 0.00 0.00 155170.73 152929.52 18.45 76473.98 490.86 41 41.00 0.00 0.00 152929.52 150741.95 18.01 75379.98 490.83 42 42.00 0.00 0.00 150741.95 148606.76 17.58 74312.17 490.80 43 43.00 0.00 0.00 148606.76 146522.68 17.16 73269.92 490.77 44 44.00 0.00 0.00 146522.68 144488.49 16.75 72252.62 490.73 45 45.00 0.00 0.00 144488.49 142503.00 16.35 71259.67 490.70 46 46.00 0.00 0.00 142503.00 140565.04 15.96 70290.50 490.67 47 47.00 0.00 0.00 140565.04 138673.48 15.58 69344.53 490.65 48 48.00 0.00 0.00 138673.48 136827.20 15.20 68421.20 490.62 49 49.00 0.00 0.00 136827.20 135025.11 14.84 67519.98 490.59 50 50.00 0.00 0.00 135025.11 133266.17 14.48 66640.33 490.56 51 51.00 0.00 0.00 133266.17 131549.34 14.14 65781.74 490.54 52 52.00 0.00 0.00 131549.34 129873.61 13.80 64943.70 490.51 53 53.00 0.00 0.00 129873.61 128234.86 13.52 64124.19 490.49 54 54.00 0.00 0.00 128234.86 126626.27 13.29 63319.78 490.46 55 55.00 0.00 0.00 126626.27 125044.37 13.07 62528.72 490.44 56 56.00 0.00 0.00 125044.37 123488.75 12.86 61750.80 490.41 57 57.00 0.00 0.00 123488.75 121958.94 12.64 60985.79 490.39 58 58.00 0.00 0.00 121958.94 120454.54 12.43 60233.49 490.36 59 59.00 0.00 0.00 120454.54 118975.11 12.23 59493.67 490.34 60 60.00 0.00 0.00 118975.11 117520.25 12.02 58766.13 490.32 61 61.00 0.00 0.00 117520.25 116089.53 11.82 58050.68 490.29 62 62.00 0.00 0.00 116089.53 114682.57 11.63 57347.10 490.27 63 63.00 0.00 0.00 114682.57 113298.97 11.44 56655.20 490.25 64 64.00 0.00 0.00 113298.97 111938.34 11.25 55974.79 490.23 65 65.00 0.00 0.00 111938.34 110600.29 11.06 55305.68 490.21 Dominion Development Resources, LLC Page 23 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report Name: SWM3, 10 Oyr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 42.82 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 1313.00 (min) Volume = 3.45 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 491.84 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #3 Storage Type = User-Defined Area Maximum Storage = 293860.53 (cu ft) Maximum Discharge = 133.08 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-3, Post 100yr Peak Flow (Qp) = 133.63 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 3.45 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (11+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: • I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 8.91 8.91 0.00 529.82 0.08 264.95 488.02 2 2.00 17.82 26.73 529.82 2110.08 0.31 1055.20 488.08 3 3.00 26.73 44.54 2110.08 4722.56 0.69 2361.63 488.18 4 4.00 35.64 62.36 4722.56 8349.34 1.22 4175.28 488.32 5 5.00 44.54 80.18 8349.34 12972.83 1.89 6487.36 488.50 6 6.00 53.45 98.00 12972.83 18581.30 2.62 9291.96 488.61 7 7.00 62.36 115.82 18581.30 25164.00 3.47 12583.74 488.73 8 8.00 71.27 133.63 25164.00 32705.90 4.45 16355.18 488.87 9 9.00 80.18 151.45 32705.90 41197.04 5.47 20601.25 489.03 10 10.00 89.09 169.27 41197.04 50651.86 6.21 25329.04 489.19 11 11.00 98.00 187.09 50651.86 61082.16 7.03 30544.59 489.38 Dominion Development Resources, LLC Page 24 (434)984-1599 Luxor Subdivision Stormwater Management Facility#3 Routed Hydrograph Report SWM3, 100yr Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 12 12.00 106.91 204.91 61082.16 72484.77 7.82 36246.30 489.58 13 13.00 115.82 222.72 72484.77 84866.47 8.53 42437.50 489.78 14 14.00 124.73 240.54 84866.47 98226.55 9.33 49117.94 490.01 15 15.00 133.63 258.36 98226.55 112486.86 11.32 56249.09 490.24 16 16.00 127.69 261.33 112486.86 126687.10 13.30 63350.20 490.46 17 17.00 121.76 249.45 126687.10 139903.97 15.82 69959.90 490.66 18 18.00 115.82 237.57 139903.97 152109.06 18.29 76063.67 490.85 19 19.00 109.88 225.69 152109.06 163315.18 20.60 81667.89 491.02 20 20.00 103.94 213.81 163315.18 173525.70 23.00 86774.35 491.17 21 21.00 98.00 201.94 173525.70 182749.10 25.17 91387.14 491.30 22 22.00 92.06 190.06 182749.10 191012.90 27.12 95520.01 491.42 23 23.00 86.12 178.18 191012.90 198303.39 29.51 99166.45 491.53 24 24.00 80.18 166.30 198303.39 204517.20 33.17 102275.18 491.61 25 25.00 74.24 154.42 204517.20 209619.51 36.17 104827.84 491.68 26 26.00 68.30 142.54 209619.51 213686.08 38.56 106862.32 491.74 27 27.00 62.36 130.66 213686.08 216787.49 40.38 108413.94 491.78 28 28.00 56.42 118.79 216787.49 218989.52 41.68 109515.60 491.81 29 29.00 50.48 106.91 218989.52 220353.45 42.48 110197.97 491.83 30 30.00 44.54 95.03 220353.45 220936.41 42.82 110489.62 491.84 31 31.00 38.61 83.15 220936.41 220791.61 42.74 110417.18 491.84 32 32.00 32.67 71.27 220791.61 219968.66 42.26 110005.46 491.83 33 33.00 26.73 59.39 219968.66 218513.77 41.40 109277.59 491.81 34 34.00 20.79 47.51 218513.77 216470.01 40.20 108255.10 491.78 35 35.00 14.85 35.64 216470.01 213877.50 38.67 106958.09 491.74 36 36.00 8.91 23.76 213877.50 210773.65 36.85 105405.25 491.70 37 37.00 2.97 11.88 210773.65 207193.31 34.74 103614.02 491.65 38 38.00 0.00 2.97 207193.31 203340.94 32.47 101686.71 491.60 39 39.00 0.00 0.00 203340.94 199579.11 30.26 99804.68 491.54 40 40.00 0.00 0.00 199579.11 196066.77 28.31 98047.54 491.50 41 41.00 0.00 0.00 196066.77 192717.58 27.52 96372.55 491.45 42 42.00 0.00 0.00 192717.58 189461.70 26.76 94744.23 491.40 43 43.00 0.00 0.00 189461.70 186296.55 26.01 93161.28 491.35 44 44.00 0.00 0.00 186296.55 183219.58 25.29 91622.43 491.31 45 45.00 0.00 0.00 183219.58 180228.35 24.58 90126.47 491.27 46 46.00 0.00 0.00 180228.35 177320.46 23.90 88672.18 491.22 47 47.00 0.00 0.00 177320.46 174493.60 23.23 87258.41 491.18 48 48.00 0.00 0.00 174493.60 171745.49 22.58 85884.04 491.14 49 49.00 0.00 0.00 171745.49 169073.96 21.95 84547.96 491.10 50 50.00 0.00 0.00 169073.96 166476.87 21.34 83249.10 491.07 51 51.00 0.00 0.00 166476.87 163952.14 20.75 81986.44 491.03 52 52.00 0.00 0.00 163952.14 161496.80 20.18 80758.49 490.99 53 53.00 0.00 0.00 161496.80 159104.14 19.70 79561.92 490.96 54 54.00 0.00 0.00 159104.14 156768.76 19.23 78394.00 490.92 55 55.00 0.00 0.00 156768.76 154489.29 18.77 77254.03 490.89 56 56.00 0.00 0.00 154489.29 152264.38 18.32 76141.35 490.85 57 57.00 0.00 0.00 152264.38 150092.74 17.88 75055.31 490.82 58 58.00 0.00 0.00 150092.74 147973.09 17.45 73995.27 490.79 59 59.00 0.00 0.00 147973.09 145904.18 17.04 72960.61 490.76 60 60.00 0.00 0.00 145904.18 143884.80 16.63 71950.71 490.73 61 61.00 0.00 0.00 143884.80 141913.76 16.23 70965.00 490.70 62 62.00 0.00 0.00 141913.76 139989.91 15.84 70002.88 490.67 63 63.00 0.00 0.00 139989.91 138112.11 15.46 69063.79 490.64 64 64.00 0.00 0.00 138112.11 136279.27 15.09 68147.18 490.61 65 65.00 0.00 0.00 136279.27 134490.31 14.73 67252.52 490.58 66 66.00 0.00 0.00 134490.31 132744.17 14.38 66379.27 490.56 Dominion Development Resources, LLC Page 25 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 75.35 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 3.89 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 3.89 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 38.20 0 0.30 Ashcroft 31.00 0 0.30 Westminster 9.10 0 0.30 Luxor 33.70 0 0.30 Overall Approximation 112.00 NA 0.30 ' [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 30.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.11 (in) Return Period = 2 (yr) Storm Duration = 0.50 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.04 0.00 2.51 2 2.00 0.04 0.07 2.51 5.02 3 3.00 0.04 0.11 2.51 7.53 4 4.00 0.04 0.15 2.51 10.05 5 5.00 0.04 0.19 2.51 12.56 6 6.00 0.04 0.22 2.51 15.07 7 7.00 0.04 0.26 2.51 17.58 8 8.00 0.04 0.30 2.51 20.09 9 9.00 0.04 0.33 2.51 22.60 10 10.00 0.04 0.37 2.51 25.12 11 11.00 0.04 0.41 2.51 27.63 12 12.00 0.04 0.44 2.51 30.14 13 13.00 0.04 0.48 2.51 32.65 Dominion Development Resources, LLC Page 26 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report DA-2, 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 14 14.00 0.04 0.52 2.51 35.16 15 15.00 0.04 0.56 2.51 37.67 16 16.00 0.04 0.59 2.51 40.19 17 17.00 0.04 0.63 2.51 42.70 18 18.00 0.04 0.67 2.51 45.21 19 19.00 0.04 0.70 2.51 47.72 20 20.00 0.04 0.74 2.51 50.23 21 21.00 0.04 0.78 2.51 52.74 22 22.00 0.04 0.82 2.51 55.25 23 23.00 0.04 0.85 2.51 57.77 24 24.00 0.04 0.89 2.51 60.28 25 25.00 0.04 0.93 2.51 62.79 26 26.00 0.04 0.96 2.51 65.30 27 27.00 0.04 1.00 2.51 67.81 28 28.00 0.04 1.04 2.51 70.32 29 29.00 0.04 1.07 2.51 72.84 30 30.00 0.04 1.11 2.51 75.35 31 31.00 0.00 1.11 -1.67 73.67 32 32.00 0.00 1.11 -1.67 72.00 33 33.00 0.00 1.11 -1.67 70.32 34 34.00 0.00 1.11 -1.67 68.65 35 35.00 0.00 1.11 -1.67 66.98 36 36.00 0.00 1.11 -1.67 65.30 37 37.00 0.00 1.11 -1.67 63.63 38 38.00 0.00 1.11 -1.67 61.95 • 39 39.00 0.00 1.11 -1.67 60.28 40 40.00 0.00 1.11 -1.67 58.60 41 41.00 0.00 1.11 -1.67 56.93 42 42.00 0.00 1.11 -1.67 55.25 43 43.00 0.00 1.11 -1.67 53.58 44 44.00 0.00 1.11 -1.67 51.91 45 45.00 0.00 1.11 -1.67 50.23 46 46.00 0.00 1.11 -1.67 48.56 47 47.00 0.00 1.11 -1.67 46.88 48 48.00 0.00 1.11 -1.67 45.21 49 49.00 0.00 1.11 -1.67 43.53 50 50.00 0.00 1.11 -1.67 41.86 51 51.00 0.00 1.11 -1.67 40.19 52 52.00 0.00 1.11 -1.67 38.51 53 53.00 0.00 1.11 -1.67 36.84 54 54.00 0.00 1.11 -1.67 35.16 55 55.00 0.00 1.11 -1.67 33.49 56 56.00 0.00 1.11 -1.67 31.81 57 57.00 0.00 1.11 -1.67 30.14 58 58.00 0.00 1.11 -1.67 28.46 59 59.00 0.00 1.11 -1.67 26.79 60 60.00 0.00 1.11 -1.67 25.12 61 61.00 0.00 1.11 -1.67 23.44 62 62.00 0.00 1.11 -1.67 21.77 63 63.00 0.00 1.11 -1.67 20.09 64 64.00 0.00 1.11 -1.67 18.42 65 65.00 0.00 1.11 -1.67 16.74 66 66.00 0.00 1.11 -1.67 15.07 Dominion Development Resources, LLC Page 27 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 109.77 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 5.67 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 5.67 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 38.20 0 0.30 Ashcroft 31.00 0 0.30 Westminster 9.10 0 0.30 Luxor 33.70 0 0.30 Overall Approximation 112.00 NA 0.30 • [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 30.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.62 (in) Return Period = User Defined (yr) Storm Duration = 0.50 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.05 0.00 3.66 2 2.00 0.05 0.11 3.66 7.32 3 3.00 0.05 0.16 3.66 10.98 4 4.00 0.05 0.22 3.66 14.64 5 5.00 0.05 0.27 3.66 18.30 6 6.00 0.05 0.32 3.66 21.95 7 7.00 0.05 0.38 3.66 25.61 8 8.00 0.05 0.43 3.66 29.27 9 9.00 0.05 0.49 3.66 32.93 10 10.00 0.05 0.54 3.66 36.59 11 11.00 0.05 0.59 3.66 40.25 12 12.00 0.05 0.65 3.66 43.91 13 13.00 0.05 0.70 3.66 47.57 Dominion Development Resources, LLC Page 28 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report DA-2, l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 14 14.00 0.05 0.76 3.66 51.23 15 15.00 0.05 0.81 3.66 54.89 16 16.00 0.05 0.86 3.66 58.55 17 17.00 0.05 0.92 3.66 62.20 18 18.00 0.05 0.97 3.66 65.86 19 19.00 0.05 1.03 3.66 69.52 20 20.00 0.05 1.08 3.66 73.18 21 21.00 0.05 1.13 3.66 76.84 22 22.00 0.05 1.19 3.66 80.50 23 23.00 0.05 1.24 3.66 84.16 24 24.00 0.05 1.30 3.66 87.82 25 25.00 0.05 1.35 3.66 91.48 26 26.00 0.05 1.40 3.66 95.14 27 27.00 0.05 1.46 3.66 98.79 28 28.00 0.05 1.51 3.66 102.45 29 29.00 0.05 1.57 3.66 106.11 30 30.00 0.05 1.62 3.66 109.77 31 31.00 0.00 1.62 -2.44 107.33 32 32.00 0.00 1.62 -2.44 104.89 33 33.00 0.00 1.62 -2.44 102.45 34 34.00 0.00 1.62 -2.44 100.01 35 35.00 0.00 1.62 -2.44 97.58 36 36.00 0.00 1.62 -2.44 95.14 37 37.00 0.00 1.62 -2.44 92.70 38 38.00 0.00 1.62 -2.44 90.26 • 39 39.00 0.00 1.62 -2.44 87.82 40 40.00 0.00 1.62 -2.44 85.38 41 41.00 0.00 1.62 -2.44 82.94 42 42.00 0.00 1.62 -2.44 80.50 43 43.00 0.00 1.62 -2.44 78.06 44 44.00 0.00 1.62 -2.44 75.62 45 45.00 0.00 1.62 -2.44 73.18 46 46.00 0.00 1.62 -2.44 70.74 47 47.00 0.00 1.62 -2.44 68.30 48 48.00 0.00 1.62 -2.44 65.86 49 49.00 0.00 1.62 -2.44 63.42 50 50.00 0.00 1.62 -2.44 60.98 51 51.00 0.00 1.62 -2.44 58.55 52 52.00 0.00 1.62 -2.44 56.11 53 53.00 0.00 1.62 -2.44 53.67 54 54.00 0.00 1.62 -2.44 51.23 55 55.00 0.00 1.62 -2.44 48.79 56 56.00 0.00 1.62 -2.44 46.35 57 57.00 0.00 1.62 -2.44 43.91 58 58.00 0.00 1.62 -2.44 41.47 59 59.00 0.00 1.62 -2.44 39.03 60 60.00 0.00 1.62 -2.44 36.59 61 61.00 0.00 1.62 -2.44 34.15 62 62.00 0.00 1.62 -2.44 31.71 63 63.00 0.00 1.62 -2.44 29.27 64 64.00 0.00 1.62 -2.44 26.83 65 65.00 0.00 1.62 -2.44 24.39 66 66.00 0.00 1.62 -2.44 21.95 . Dominion Development Resources, LLC Page 29 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report Name: DA-2, 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 161.44 (cfs) Time to Peak (Tp) = 30.00 (min) Time of Base (Tb) = 75.00 (min) Volume = 8.34 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 8.34 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 38.20 0 0.30 Ashcroft 31.00 0 0.30 Westminster 9.10 0 0.30 Luxor 33.70 0 0.30 Overall Approximation 112.00 NA 0.30 ' [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 30.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 2.38 (in) Return Period = 100 (yr) Storm Duration = 0.50 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.08 0.00 5.38 2 2.00 0.08 0.16 5.38 10.76 3 3.00 0.08 0.24 5.38 16.14 4 4.00 0.08 0.32 5.38 21.53 5 5.00 0.08 0.40 5.38 26.91 6 6.00 0.08 0.48 5.38 32.29 7 7.00 0.08 0.56 5.38 37.67 8 8.00 0.08 0.64 5.38 43.05 9 9.00 0.08 0.71 5.38 48.43 10 10.00 0.08 0.79 5.38 53.81 11 11.00 0.08 0.87 5.38 59.20 12 12.00 0.08 0.95 5.38 64.58 13 13.00 0.08 1.03 5.38 69.96 Dominion Development Resources, LLC Page 30 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Pre-Development Hydrograph Report DA-2, 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 14 14.00 0.08 1.11 5.38 75.34 15 15.00 0.08 1.19 5.38 80.72 16 16.00 0.08 1.27 5.38 86.10 17 17.00 0.08 1.35 5.38 91.49 18 18.00 0.08 1.43 5.38 96.87 19 19.00 0.08 1.51 5.38 102.25 20 20.00 0.08 1.59 5.38 107.63 21 21.00 0.08 1.67 5.38 113.01 22 22.00 0.08 1.75 5.38 118.39 23 23.00 0.08 1.83 5.38 123.77 24 24.00 0.08 1.91 5.38 129.16 25 25.00 0.08 1.99 5.38 134.54 26 26.00 0.08 2.06 5.38 139.92 27 27.00 0.08 2.14 5.38 145.30 28 28.00 0.08 2.22 5.38 150.68 29 29.00 0.08 2.30 5.38 156.06 30 30.00 0.08 2.38 5.38 161.44 31 31.00 0.00 2.38 -3.59 157.86 32 32.00 0.00 2.38 -3.59 154.27 33 33.00 0.00 2.38 -3.59 150.68 34 34.00 0.00 2.38 -3.59 147.09 35 35.00 0.00 2.38 -3.59 143.51 36 36.00 0.00 2.38 -3.59 139.92 37 37.00 0.00 2.38 -3.59 136.33 38 38.00 0.00 2.38 -3.59 132.74 . 39 39.00 0.00 2.38 -3.59 129.16 40 40.00 0.00 2.38 -3.59 125.57 41 41.00 0.00 2.38 -3.59 121.98 42 42.00 0.00 2.38 -3.59 118.39 43 43.00 0.00 2.38 -3.59 114.80 44 44.00 0.00 2.38 -3.59 111.22 45 45.00 0.00 2.38 -3.59 107.63 46 46.00 0.00 2.38 -3.59 104.04 47 47.00 0.00 2.38 -3.59 100.45 48 48.00 0.00 2.38 -3.59 96.87 49 49.00 0.00 2.38 -3.59 93.28 50 50.00 0.00 2.38 -3.59 89.69 51 51.00 0.00 2.38 -3.59 86.10 52 52.00 0.00 2.38 -3.59 82.52 53 53.00 0.00 2.38 -3.59 78.93 54 54.00 0.00 2.38 -3.59 75.34 55 55.00 0.00 2.38 -3.59 71.75 56 56.00 0.00 2.38 -3.59 68.17 57 57.00 0.00 2.38 -3.59 64.58 58 58.00 0.00 2.38 -3.59 60.99 59 59.00 0.00 2.38 -3.59 57.40 60 60.00 0.00 2.38 -3.59 53.81 61 61.00 0.00 2.38 -3.59 50.23 62 62.00 0.00 2.38 -3.59 46.64 63 63.00 0.00 2.38 -3.59 43.05 64 64.00 0.00 2.38 -3.59 39.46 65 65.00 0.00 2.38 -3.59 35.88 66 66.00 0.00 2.38 -3.59 32.29 Dominion Development Resources, LLC Page 31 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 135.41 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 5.83 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 5.83 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana (1/2 acre Lots) 36.40 0 0.50 Pavilions-I 17.10 0 0.75 Woods/Brush 25.60 0 0.30 Pavilions-II 4.90 0 0.50 Undeveloped Pond Area 4.00 0 0.53 Commercial 11.25 0 0.85 ` Overall Approximation 99.25 NA 0.53 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 25.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.06 (in) Return Period = 2 (yr) Storm Duration = 0.42 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.04 0.00 5.42 2 2.00 0.04 0.08 5.42 10.83 3 3.00 0.04 0.13 5.42 16.25 4 4.00 0.04 0.17 5.42 21.67 5 5.00 0.04 0.21 5.42 27.08 6 6.00 0.04 0.25 5.42 32.50 7 7.00 0.04 0.30 5.42 37.92 8 8.00 0.04 0.34 5.42 43.33 9 9.00 0.04 0.38 5.42 48.75 10 10.00 0.04 0.42 5.42 54.17 11 11.00 0.04 0.47 5.42 59.58 Dominion Development Resources, LLC Page 32 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report DA-2, Post 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 12 12.00 0.04 0.51 5.42 65.00 13 13.00 0.04 0.55 5.42 70.41 14 14.00 0.04 0.59 5.42 75.83 15 15.00 0.04 0.64 5.42 81.25 16 16.00 0.04 0.68 5.42 86.66 17 17.00 0.04 0.72 5.42 92.08 18 18.00 0.04 0.76 5.42 97.50 19 19.00 0.04 0.80 5.42 102.91 20 20.00 0.04 0.85 5.42 108.33 21 21.00 0.04 0.89 5.42 113.75 22 22.00 0.04 0.93 5.42 119.16 23 23.00 0.04 0.97 5.42 124.58 24 24.00 0.04 1.02 5.42 130.00 25 25.00 0.04 1.06 5.42 135.41 26 26.00 0.00 1.06 -3.61 131.80 27 27.00 0.00 1.06 -3.61 128.19 28 28.00 0.00 1.06 -3.61 124.58 29 29.00 0.00 1.06 -3.61 120.97 30 30.00 0.00 1.06 -3.61 117.36 31 31.00 0.00 1.06 -3.61 113.75 32 32.00 0.00 1.06 -3.61 110.14 33 33.00 0.00 1.06 -3.61 106.52 34 34.00 0.00 1.06 -3.61 102.91 35 35.00 0.00 1.06 -3.61 99.30 36 36.00 0.00 1.06 -3.61 95.69 37 37.00 0.00 1.06 -3.61 92.08 38 38.00 0.00 1.06 -3.61 88.47 39 39.00 0.00 1.06 -3.61 84.86 40 40.00 0.00 1.06 -3.61 81.25 41 41.00 0.00 1.06 -3.61 77.64 42 42.00 0.00 1.06 -3.61 74.03 43 43.00 0.00 1.06 -3.61 70.41 44 44.00 0.00 1.06 -3.61 66.80 45 45.00 0.00 1.06 -3.61 63.19 46 46.00 0.00 1.06 -3.61 59.58 47 47.00 0.00 1.06 -3.61 55.97 48 48.00 0.00 1.06 -3.61 52.36 49 49.00 0.00 1.06 -3.61 48.75 50 50.00 0.00 1.06 -3.61 45.14 51 51.00 0.00 1.06 -3.61 41.53 52 52.00 0.00 1.06 -3.61 37.92 53 53.00 0.00 1.06 -3.61 34.30 54 54.00 0.00 1.06 -3.61 30.69 55 55.00 0.00 1.06 -3.61 27.08 56 56.00 0.00 1.06 -3.61 23.47 57 57.00 0.00 1.06 -3.61 19.86 58 58.00 0.00 1.06 -3.61 16.25 59 59.00 0.00 1.06 -3.61 12.64 60 60.00 0.00 1.06 -3.61 9.03 61 61.00 0.00 1.06 -3.61 5.42 62 62.00 0.00 1.06 -3.61 1.81 63 62.50 0.00 1.06 -1.81 0.00 Dominion Development Resources,LLC Page 33 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 192.80 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 8.30 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 8.30 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana (1/2 acre Lots) 36.40 0 0.50 Pavilions-I 17.10 0 0.75 Woods/Brush 25.60 0 0.30 Pavilions-II 4.90 0 0.50 Undeveloped Pond Area 4.00 0 0.53 Commercial 11.25 0 0.85 • Overall Approximation 99.25 NA 0.53 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 25.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.51 (in) Return Period = User Defined (yr) Storm Duration = 0.42 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.06 0.00 7.71 2 2.00 0.06 0.12 7.71 15.42 3 3.00 0.06 0.18 7.71 23.14 4 4.00 0.06 0.24 7.71 30.85 5 5.00 0.06 0.30 7.71 38.56 6 6.00 0.06 0.36 7.71 46.27 7 7.00 0.06 0.42 7.71 53.98 8 8.00 0.06 0.48 7.71 61.70 9 9.00 0.06 0.54 7.71 69.41 10 10.00 0.06 0.60 7.71 77.12 11 11.00 0.06 0.66 7.71 84.83 Dominion Development Resources, LLC Page 34 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 , Post-Development Hydrograph Report DA-2, Post l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 12 12.00 0.06 0.72 7.71 92.54 13 13.00 0.06 0.78 7.71 100.26 14 14.00 0.06 0.84 7.71 107.97 15 15.00 0.06 0.90 7.71 115.68 16 16.00 0.06 0.96 7.71 123.39 17 17.00 0.06 1.03 7.71 131.10 18 18.00 0.06 1.09 7.71 138.81 19 19.00 0.06 1.15 7.71 146.53 20 20.00 0.06 1.21 7.71 154.24 21 21.00 0.06 1.27 7.71 161.95 22 22.00 0.06 1.33 7.71 169.66 23 23.00 0.06 1.39 7.71 177.37 24 24.00 0.06 1.45 7.71 185.09 25 25.00 0.06 1.51 7.71 192.80 26 26.00 0.00 1.51 -5.14 187.66 27 27.00 0.00 1.51 -5.14 182.52 28 28.00 0.00 1.51 -5.14 177.37 29 29.00 0.00 1.51 -5.14 172.23 30 30.00 0.00 1.51 -5.14 167.09 31 31.00 0.00 1.51 -5.14 161.95 32 32.00 0.00 1.51 -5.14 156.81 33 33.00 0.00 1.51 -5.14 151.67 34 34.00 0.00 1.51 -5.14 146.53 35 35.00 0.00 1.51 -5.14 141.39 36 36.00 0.00 1.51 -5.14 136.24 ' 37 37.00 0.00 1.51 -5.14 131.10 38 38.00 0.00 1.51 -5.14 125.96 39 39.00 0.00 1.51 -5.14 120.82 40 40.00 0.00 1.51 -5.14 115.68 41 41.00 0.00 1.51 -5.14 110.54 42 42.00 0.00 1.51 -5.14 105.40 43 43.00 0.00 1.51 -5.14 100.26 44 44.00 0.00 1.51 -5.14 95.11 45 45.00 0.00 1.51 -5.14 89.97 46 46.00 0.00 1.51 -5.14 84.83 47 47.00 0.00 1.51 -5.14 79.69 48 48.00 0.00 1.51 -5.14 74.55 49 49.00 0.00 1.51 -5.14 69.41 50 50.00 0.00 1.51 -5.14 64.27 51 51.00 0.00 1.51 -5.14 59.12 52 52.00 0.00 1.51 -5.14 53.98 53 53.00 0.00 1.51 -5.14 48.84 54 54.00 0.00 1.51 -5.14 43.70 55 55.00 0.00 1.51 -5.14 38.56 56 56.00 0.00 1.51 -5.14 33.42 57 57.00 0.00 1.51 -5.14 28.28 58 58.00 0.00 1.51 -5.14 23.14 59 59.00 0.00 1.51 -5.14 17.99 60 60.00 0.00 1.51 -5.14 12.85 61 61.00 0.00 1.51 -5.14 7.71 62 62.00 0.00 1.51 -5.14 2.57 63 62.50 0.00 1.51 -2.57 0.00 Dominion Development Resources,LLC Page 35 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report Name: DA-2, Post 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 279.88 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 62.50 (min) Volume = 12.05 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 12.05 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area ON Runoff Coef Fontana (1/2 acre Lots) 36.40 0 0.50 Pavilions-I 17.10 0 0.75 Woods/Brush 25.60 0 0.30 _ Pavilions-II 4.90 0 0.50 Undeveloped Pond Area 4.00 0 0.53 Commercial 11.25 0 0.85 Overall Approximation 99.25 NA 0.53 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 25.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 2.19 (in) Return Period = 100 (yr) Storm Duration = 0.42 (hr) [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.09 0.00 11.20 2 2.00 0.09 0.18 11.20 22.39 3 3.00 0.09 0.26 11.20 33.59 4 4.00 0.09 0.35 11.20 44.78 5 5.00 0.09 0.44 11.20 55.98 6 6.00 0.09 0.53 11.20 67.17 7 7.00 0.09 0.61 11.20 78.37 8 8.00 0.09 0.70 11.20 89.56 9 9.00 0.09 0.79 11.20 100.76 10 10.00 0.09 0.88 11.20 111.95 11 11.00 0.09 0.96 11.20 123.15 Dominion Development Resources,LLC Page 36 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Post-Development Hydrograph Report DA-2, Post 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 12 12.00 0.09 1.05 11.20 134.34 13 13.00 0.09 1.14 11.20 145.54 14 14.00 0.09 1.23 11.20 156.73 15 15.00 0.09 1.31 11.20 167.93 16 16.00 0.09 1.40 11.20 179.12 17 17.00 0.09 1.49 11.20 190.32 18 18.00 0.09 1.58 11.20 201.51 19 19.00 0.09 1.66 11.20 212.71 20 20.00 0.09 1.75 11.20 223.90 21 21.00 0.09 1.84 11.20 235.10 22 22.00 0.09 1.93 11.20 246.29 23 23.00 0.09 2.01 11.20 257.49 24 24.00 0.09 2.10 11.20 268.68 25 25.00 0.09 2.19 11.20 279.88 26 26.00 0.00 2.19 -7.46 272.41 27 27.00 0.00 2.19 -7.46 264.95 28 28.00 0.00 2.19 -7.46 257.49 29 29.00 0.00 2.19 -7.46 250.02 30 30.00 0.00 2.19 -7.46 242.56 31 31.00 0.00 2.19 -7.46 235.10 32 32.00 0.00 2.19 -7.46 227.63 33 33.00 0.00 2.19 -7.46 220.17 34 34.00 0.00 2.19 -7.46 212.71 35 35.00 0.00 2.19 -7.46 205.24 36 36.00 0.00 2.19 -7.46 197.78 • 37 37.00 0.00 2.19 -7.46 190.32 38 38.00 0.00 2.19 -7.46 182.85 39 39.00 0.00 2.19 -7.46 175.39 40 40.00 0.00 2.19 -7.46 167.93 41 41.00 0.00 2.19 -7.46 160.46 42 42.00 0.00 2.19 -7.46 153.00 43 43.00 0.00 2.19 -7.46 145.54 44 44.00 0.00 2.19 -7.46 138.07 45 45.00 0.00 2.19 -7.46 130.61 46 46.00 0.00 2.19 -7.46 123.15 47 47.00 0.00 2.19 -7.46 115.68 48 48.00 0.00 2.19 -7.46 108.22 49 49.00 0.00 2.19 -7.46 100.76 50 50.00 0.00 2.19 -7.46 93.29 51 51.00 0.00 2.19 -7.46 85.83 52 52.00 0.00 2.19 -7.46 78.37 53 53.00 0.00 2.19 -7.46 70.90 54 54.00 0.00 2.19 -7.46 63.44 55 55.00 0.00 2.19 -7.46 55.98 56 56.00 0.00 2.19 -7.46 48.51 57 57.00 0.00 2.19 -7.46 41.05 58 58.00 0.00 2.19 -7.46 33.59 59 59.00 0.00 2.19 -7.46 26.12 60 60.00 0.00 2.19 -7.46 18.66 61 61.00 0.00 2.19 -7.46 11.20 62 62.00 0.00 2.19 -7.46 3.73 63 62.50 0.00 2.19 -3.73 0.00 . Dominion Development Resources, LLC Page 37 (434)984-1599 . , Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report Name: DA-2 & SWM3, 2yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 146.11 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1275.00 (min) Volume = 7.56 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: DA-2, Post 2yr Type: Modified Rational Peak Flow (Qp) = 135.41 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) Name: SWM3, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 12.50 (cfs) Time to Peak (Tp) = 33.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 5.46 2 2.00 10.99 3 3.00 16.60 ' 4 4.00 22.28 5 5.00 28.03 6 6.00 33.86 7 7.00 39.76 8 8.00 45.67 9 9.00 51.63 10 10.00 57.66 11 11.00 63.75 12 12.00 69.89 13 13.00 75.96 14 14.00 81.89 15 15.00 87.86 16 16.00 93.83 17 17.00 99.73 18 18.00 105.50 19 19.00 111.25 20 20.00 116.97 21 21.00 122.68 22 22.00 128.36 23 23.00 134.27 24 24.00 140.22 25 25.00 146.11 26 26.00 142.91 27 27.00 139.66 28 28.00 136.36 29 29.00 132.99 30 30.00 129.58 31 31.00 126.11 Dominion Development Resources, LLC Page 38 (434)984-1599 , Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report DA-2 & SWM3, 2yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 32 32.00 122.59 33 33.00 119.02 34 34.00 115.40 35 35.00 111.73 36 36.00 108.01 37 37.00 104.25 38 38.00 100.45 39 39.00 96.64 40 40.00 92.83 41 41.00 89.03 42 42.00 85.23 43 43.00 81.43 44 44.00 77.64 45 45.00 73.84 46 46.00 70.06 47 47.00 66.27 48 48.00 62.49 49 49.00 58.71 50 50.00 54.93 51 51.00 51.16 52 52.00 47.39 53 53.00 43.62 54 54.00 39.91 9 55 55.00 36.24 56 56.00 32.57 57 57.00 28.89 • 58 58.00 25.22 59 59.00 21.55 60 60.00 17.88 61 61.00 14.21 62 62.00 10.53 63 63.00 8.67 64 64.00 8.61 65 65.00 8.55 66 66.00 8.49 67 67.00 8.44 68 68.00 8.38 69 69.00 8.32 70 70.00 8.26 71 71.00 8.21 72 72.00 8.15 73 73.00 8.10 74 74.00 8.04 75 75.00 7.99 76 76.00 7.93 77 77.00 7.88 78 78.00 7.82 79 79.00 7.77 80 80.00 7.72 Dominion Development Resources,LLC Page 39 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report Name: DA-2 & SWM3, l0yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 210.63 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1297.00 (min) Volume = 10.71 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: DA-2, Post l0yr Type: Modified Rational Peak Flow (Qp) = 192.80 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) Name: SWM3, l0yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 20.89 (cfs) Time to Peak (Tp) = 32.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 7.77 2 2.00 15.64 • 3 3.00 23.62 4 4.00 31.70 5 5.00 39.88 6 6.00 48.16 7 7.00 56.47 8 8.00 64.86 9 9.00 73.34 10 10.00 81.90 11 11.00 90.40 12 12.00 98.73 13 13.00 107.11 14 14.00 115.54 15 15.00 123.82 16 16.00 132.09 17 17.00 140.34 18 18.00 149.24 19 19.00 158.09 20 20.00 166.85 21 21.00 175.52 22 22.00 184.47 23 23.00 193.31 24 24.00 202.03 25 25.00 210.63 26 26.00 206.25 27 27.00 201.76 28 28.00 197.15 29 29.00 192.43 30 30.00 187.63 • Dominion Development Resources, LLC Page 40 (434)984-1599 Luxor Subdivision • Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report DA-2 & SWM3, l0yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 31 31.00 182.73 32 32.00 177.70 33 33.00 172.55 34 34.00 167.29 35 35.00 161.92 36 36.00 156.45 37 37.00 150.92 38 38.00 145.33 39 39.00 139.73 40 40.00 134.13 41 41.00 128.55 42 42.00 122.98 43 43.00 117.42 44 44.00 111.86 45 45.00 106.32 46 46.00 100.79 47 47.00 95.27 48 48.00 89.75 49 49.00 84.25 50 50.00 78.75 51 51.00 73.26 52 52.00 67.78 53 53.00 62.36 54 54.00 57.00 55 55.00 51.63 56 56.00 46.28 ► 57 57.00 40.92 58 58.00 35.57 59 59.00 30.22 60 60.00 24.88 61 61.00 19.54 62 62.00 14.20 63 63.00 11.44 64 64.00 11.25 65 65.00 11.06 66 66.00 10.87 67 67.00 10.69 68 68.00 10.52 69 69.00 10.34 70 70.00 10.17 71 71.00 10.00 72 72.00 9.84 73 73.00 9.67 74 74.00 9.51 75 75.00 9.35 76 76.00 9.23 77 77.00 9.17 78 78.00 9.11 79 79.00 9.05 80 80.00 8.99 81 81.00 8.92 82 82.00 8.86 83 83.00 8.80 84 84.00 8.74 • Dominion Development Resources, LLC Page 41 (434)984-1599 t Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report Name: DA-2 & SWM3, 100yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) 316.04 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1313.00 (min) Volume = 15.50 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: SWM3, 100yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 42.82 (cfs) Time to Peak (Tp) = 30.00 (min) Time Step = 1.00 (min) Name: DA-2, Post 100yr Type: Modified Rational Peak Flow (Qp) = 279.88 (cfs) Time to Peak (Tp) = 25.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 11.27 2 2.00 22.70 3 3.00 34.27 4 4.00 46.00 5 5.00 57.87 6 6.00 69.79 7 7.00 81.84 8 8.00 94.01 9 9.00 106.22 10 10.00 118.16 11 11.00 130.17 12 12.00 142.16 13 13.00 154.06 14 14.00 166.06 15 15.00 179.25 16 16.00 192.42 17 17.00 206.14 18 18.00 219.80 19 19.00 233.30 20 20.00 246.90 21 21.00 260.27 22 22.00 273.41 23 23.00 287.00 24 24.00 301.85 25 25.00 316.04 26 26.00 310.97 27 27.00 305.33 28 28.00 299.17 29 29.00 292.51 30 30.00 285.38 31 31.00 277.84 Dominion Development Resources, LLC Page 42 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Combined Hydrograph Report DA-2 & SWM3, 100yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 32 32.00 269.89 33 33.00 261.57 34 34.00 252.90 35 35.00 243.92 36 36.00 234.63 37 37.00 225.06 38 38.00 215.33 39 39.00 205.65 40 40.00 196.24 41 41.00 187.98 42 42.00 179.75 43 43.00 171.55 44 44.00 163.36 45 45.00 155.19 46 46.00 147.04 47 47.00 138.91 48 48.00 130.80 49 49.00 122.71 50 50.00 114.63 51 51.00 106.58 52 52.00 98.55 53 53.00 90.60 54 54.00 82.67 55 55.00 74.74 56 56.00 66.83 57 57.00 58.93 58 58.00 51.04 59 59.00 43.16 60 60.00 35.29 61 61.00 27.42 62 62.00 19.57 63 63.00 15.46 64 64.00 15.09 65 65.00 14.73 66 66.00 14.38 67 67.00 14.03 68 68.00 13.70 69 69.00 13.45 70 70.00 13.23 71 71.00 13.01 72 72.00 12.79 73 73.00 12.58 74 74.00 12.37 75 75.00 12.17 76 76.00 11.96 77 77.00 11.77 78 78.00 11.57 79 79.00 11.38 80 80.00 11.19 81 81.00 11.00 82 82.00 10.82 83 83.00 10.64 84 84.00 10.46 85 85.00 10.29 Dominion Development Resources, LLC Page 43 (434)984-1599 r Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report Type : Stand Pipe Name : SWM #2 Riser [RATING CURVE LIMIT] Minimum Elevation = 427.21 (ft) Maximum Elevation = 444.00 (ft) Elevation Increment = 0.25 (ft) [STAND PIPE INFORMATION] [ORIFICE INFORMATION] Diameter = 5.00 (ft) Crest Length = 15.71 (ft) Effective Crest Length = 15.71 (ft) Orifice Coefficient = 0.60 Fractional Open Area = 1.00 [ORIFICE EQUATION] Q = Co*A( (2gh)/k)^0.5 [DEFINITIONS] Co = Orifice Coefficient A = Wetted Area, (sq ft) [WEIR INFORMATION] Crest Elevation = 434.84 (ft) Weir Coefficient = 3.33 Exponential = 1.50 [WEIR EQUATION] Q = Cw * L * HAexp [DEFINITIONS] Cw = Weir Coefficient H = Headwater depth above inlet control section invert ft L = Crest lenght ft Dominion Development Resources, LLC Page 44 (434)984-1599 • Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report SWM #2 Riser [CULVERT INFORMATION] Type : Circular Concrete - Square Edge with Headwall [OUTLET STRUCTURE INFORMATION] Diameter = 28.00 (in) Invert Elevation = 427.21 (ft) Pipe Length = 180.00 (ft) Slope = 0.03 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 424.14 (ft) Number of Barrels = 1 [UNSUBMERGED EQUATION] H/Diam = Hc/Diam+K*(Q/(A*DiamA0.5) ) 'M-0.5*S Coefficient K = 0.01 Coefficient M = 2.00 Q Maximum = 22.86 [SUBMERGED EQUATION] H/Diam = c*(Q/(A*Diam"0.5))'2+Y-0.5*S Coefficient c = 0.04 Coefficient Y = 0.67 Q Minimum = 26.13 [DEFINITIONS] H = Headwater depth above inlet control section invert, (ft) Diam = Interior height of culvert barrel, (ft) He = Specific head at critical depth (dc+Vc"2/2g) , (ft) Q = Discharge, (cfs) A = Full cross sectional area of culvert barrel, (sq ft) S = Culvert barrel slope, (ft/ft) [STAND PIPE STAGE VS. DISCHARGE] Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 434.21 7.00 0.00 0.00 0.00 50.15 0.00 434.71 7.50 0.00 0.00 0.00 52.39 0.00 435.21 8.00 0.00 0.00 11.77 54.54 11.77 435.71 8.50 0.00 0.00 42.45 56.60 42.45 436.21 9.00 0.00 0.00 83.88 58.60 58.60 436.71 9.50 0.00 0.00 119.30 60.53 60.53 437.21 10.00 0.00 0.00 145.49 62.39 62.39 437.71 10.50 0.00 0.00 160.10 64.21 64.21 438.21 11.00 0.00 0.00 173.49 65.97 65.97 438.71 11.50 0.00 0.00 185.91 67.69 67.69 439.21 12.00 0.00 0.00 197.56 69.37 69.37 439.71 12.50 0.00 0.00 208.55 71.00 71.00 440.21 13.00 0.00 0.00 219.00 72.60 72.60 440.71 13.50 0.00 0.00 228.96 74.17 74.17 441.21 14.00 0.00 0.00 238.52 75.70 75.70 441.71 14.50 0.00 0.00 247.70 77.20 77.20 442.21 15.00 0.00 0.00 256.56 78.68 78.68 442.71 15.50 0.00 0.00 265.12 80.08 80.08 443.21 16.00 0.00 0.00 273.41 81.15 81.15 443.71 16.50 0.00 0.00 281.46 82.21 82.21 Dominion Development Resources, LLC Page 45 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Outlet Structure Report Type : Trapezoidal Weir Name : SWM #2 Overflow [RATING CURVE LIMIT] Minimum Elevation = 441.00 (ft) Maximum Elevation = 444.60 (ft) Elevation Increment = 0.20 (ft) [OUTLET STRUCTURE INFORMATION] Crest Length = 16.00 (ft) Angle of Walls = 33.3333 Crest Elevation = 441.00 (ft) Weir Coefficient = 3.33 Exponential = 1.50 [TRAPEZOIDAL EQUATION] Q = Cw * ( L + 0.8H * tan ( ang/2.0 ) ) * H"exp [DEFINITIONS] Cw = Weir Coefficient H = Headwater depth above inlet control section invert L = Crest lenght ang = Angle of the walls [MAXIMUM DISCHARGE] Q = 383.54 (cfs) [WEIR STAGE VS. DISCHARGE] Elevation (ft) Stage (ft) Discharge (cfs) 441.00 0.00 0.00 441.20 0.20 4.78 441.40 0.40 13.56 441.60 0.60 24.98 441.80 0.80 38.58 442.00 1.00 54.08 442.20 1.20 71.30 442.40 1.40 90.11 442.60 1.60 110.41 442.80 1.80 132.14 443.00 2.00 155.21 443.20 2.20 179.58 443.40 2.40 205.22 443.60 2.60 232.06 443.80 2.80 260.10 444.00 3.00 289.28 444.20 3.20 319.60 444.40 3.40 351.03 444.60 3.60 383.54 Dominion Development Resources,LLC Page 46 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Name: Existing Westminister Pond (#2) [RATING CURVE LIMIT] Minimum Elevation = 427.21 (ft) Maximum Elevation = 444.00 (ft) Elevation Increment = 0.20 (ft) [STAGE STORAGE INFORMATION] Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 434.84 0.00 0.00 0.00 0.00 2 434.85 57970.00 28985.00 144.93 144.93 3 436.00 70995.00 64482.50 74477.29 74622.21 4 438.00 78780.00 74887.50 149775.00 224397.21 5 440.00 86752.00 82766.00 165532.00 389929.21 6 442.00 97560.00 92156.00 184312.00 574241.21 7 444.00 109513.00 103536.50 207073.00 781314.21 [DISCHARGE INFORMATION] Structure Number: 1 Type: Name: SWM #2 Riser Structure Number: 2 Type: Trapezoidal Weir Name: SWM #2 Overflow [RESERVOIR STAGE STORAGE/DISCHARGE] Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 434.84 7.60 0.00 0.00 0.00 435.01 7.80 59830.71 5983.07 3.67 435.21 8.00 62086.13 18174.76 11.77 435.41 8.20 64341.54 30817.52 22.51 435.61 8.40 66596.95 43911.37 35.34 435.81 8.60 68852.36 57456.30 49.97 436.01 8.80 71033.92 71444.93 57.81 436.21 9.00 71812.42 85729.56 58.60 436.41 9.20 72590.92 100169.90 59.38 436.61 9.40 73369.42 114765.93 60.14 436.81 9.60 74147.93 129517.67 60.90 437.01 9.80 74926.42 144425.10 61.65 437.21 10.00 75704.92 159488.24 62.39 437.41 10.20 76483.42 174707.07 63.13 437.61 10.40 77261.92 190081.61 63.85 437.81 10.60 78040.43 205611.84 64.57 438.01 10.80 78819.86 221297.87 65.27 438.21 11.00 79617.06 237141.56 65.97 438.41 11.20 80414.26 253144.70 66.67 438.61 11.40 81211.46 269307.27 67.35 438.81 11.60 82008.66 285629.28 68.03 439.01 11.80 82805.86 302110.73 68.70 Dominion Development Resources, LLC Page 47 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Existing Westminister Pond (#2) [RESERVOIR STAGE STORAGE/DISCHARGE] Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 439.21 12.00 83603.06 318751.62 69.37 439.41 12.20 84400.26 335551.96 70.03 439.61 12.40 85197.46 352511.73 70.68 439.81 12.60 85994.66 369630.94 71.33 440.01 12.80 86806.04 386911.01 71.97 440.21 13.00 87886.84 404380.30 72.60 440.41 13.20 88967.64 422065.75 73.23 440.61 13.40 90048.44 439967.35 73.86 440.81 13.60 91129.24 458085.12 74.48 441.01 13.80 92210.04 476419.05 75.09 441.21 14.00 93290.84 494969.14 75.70 441.41 14.20 94371.64 513735.39 76.31 441.61 14.40 95452.44 532717.79 76.91 441.81 14.60 96533.24 551916.36 77.50 442.01 14.80 97619.76 571331.66 78.09 442.21 15.00 98815.06 590975.15 78.68 442.41 15.20 100010.36 610857.69 79.26 442.61 15.40 101205.66 630979.29 79.84 442.81 15.60 102400.97 651339.96 80.29 443.01 15.80 103596.26 671939.68 80.73 443.21 16.00 104791.56 692778.46 81.16 443.41 16.20 105986.86 713856.30 81.58 443.61 16.40 107182.16 735173.21 82.00 443.81 16.60 108377.47 756729.17 82.42 Maximum Storage = 777428.76 (cu ft) • Maximum Discharge = 82.82 (cfs) Dominion Development Resources, LLC Page 48 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Name: SWM2, 2yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 61.36 (cfs) Time to Peak (Tp) = 48.00 (min) Time of Base (Tb) = 1292.00 (min) Volume = 7.56 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 436.93 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = Exist Westminister Pond Storage Type = User-Defined Area Maximum Storage = 777428.76 (cu ft) Maximum Discharge = 372.10 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-2 & SWM3, 2yr Peak Flow (Qp) = 146.11 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1275.00 (min) Volume = 7.56 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 5.46 5.46 0.00 321.31 0.10 160.71 434.82 2 2.00 10.99 16.44 321.31 1278.18 0.39 639.28 434.83 3 3.00 16.60 27.58 1278.18 2856.63 0.88 1428.75 434.86 4 4.00 22.28 38.87 2856.63 5043.05 1.55 2522.30 434.89 5 5.00 28.03 50.31 5043.05 7824.17 2.40 3913.28 434.94 6 6.00 33.86 61.89 7824.17 11187.03 3.43 5595.23 435.00 7 7.00 39.76 73.62 11187.03 15114.09 4.71 7559.40 435.04 8 8.00 45.67 85.42 15114.09 19583.09 6.20 9794.65 435.07 9 9.00 51.63 97.30 19583.09 24575.74 7.86 12291.80 435.11 10 10.00 57.66 109.29 24575.74 30078.39 9.69 15044.04 435.16 Dominion Development Resources, LLC Page 49 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report SWM2, 2yr [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 63.75 121.41 30078.39 36078.15 11.69 18044.92 435.21 12 12.00 69.89 133.64 36078.15 42528.36 14.40 21271.38 435.26 13 13.00 75.96 145.85 42528.36 49373.89 17.31 24695.60 435.31 14 14.00 81.89 157.86 49373.89 56581.13 20.37 28300.75 435.37 15 15.00 87.86 169.75 56581.13 64116.20 23.74 32069.97 435.43 16 16.00 93.83 181.69 64116.20 71934.99 27.57 35981.28 435.49 17 17.00 99.73 193.56 71934.99 79998.68 31.53 40015.10 435.55 18 18.00 105.50 205.23 79998.68 88280.30 35.61 44157.96 435.61 19 19.00 111.25 216.75 88280.30 96733.41 40.18 48386.80 435.68 20 20.00 116.97 228.22 96733.41 105322.36 44.82 52683.59 435.74 21 21.00 122.68 239.65 105322.36 114036.00 49.53 57042.76 435.80 22 22.00 128.36 251.03 114036.00 122988.79 52.25 61520.52 435.87 23 23.00 134.27 262.63 122988.79 132317.08 54.86 66185.97 435.93 24 24.00 140.22 274.49 132317.08 142036.75 57.58 71047.17 436.00 25 25.00 146.11 286.33 142036.75 152276.58 58.07 76167.32 436.08 26 26.00 142.91 289.02 152276.58 162632.13 58.35 81345.24 436.15 27 27.00 139.66 282.57 162632.13 172567.34 58.63 86312.98 436.22 28 28.00 136.36 276.02 172567.34 182077.29 58.88 91068.08 436.28 29 29.00 132.99 269.35 182077.29 191157.09 59.13 95608.11 436.35 30 30.00 129.58 262.57 191157.09 199801.67 59.36 99930.52 436.41 31 31.00 126.11 255.69 199801.67 208006.35 59.58 104032.96 436.46 32 32.00 122.59 248.70 208006.35 215766.58 59.78 107913.18 436.52 33 33.00 119.02 241.61 215766.58 223077.62 59.98 111568.80 436.57 34 34.00 115.40 234.42 223077.62 229934.84 60.16 114997.50 436.61 35 35.00 111.73 227.13 229934.84 236333.96 60.32 118197.14 436.66 36 36.00 108.01 219.74 236333.96 242270.74 60.47 121165.61 436.70 37 37.00 104.25 212.26 242270.74 247740.86 60.61 123900.74 436.73 38 38.00 100.45 204.69 247740.86 252740.83 60.74 126400.79 436.77 39 39.00 96.64 197.08 252740.83 257269.47 60.86 128665.16 436.80 40 40.00 92.83 189.47 257269.47 261327.97 60.96 130694.47 436.83 41 41.00 89.03 181.86 261327.97 264918.29 61.05 132489.67 436.85 42 42.00 85.23 174.25 264918.29 268042.29 61.13 134051.71 436.87 43 43.00 81.43 166.66 268042.29 270701.75 61.20 135381.47 436.89 44 44.00 77.64 159.06 270701.75 272898.44 61.25 136479.85 436.90 45 45.00 73.84 151.48 272898.44 274634.13 61.30 137347.71 436.92 46 46.00 70.06 143.90 274634.13 275910.56 61.33 137985.95 436.92 47 47.00 66.27 136.33 275910.56 276729.48 61.35 138395.42 436.93 48 48.00 62.49 128.76 276729.48 277092.61 61.36 138576.99 436.93 49 49.00 58.71 121.20 277092.61 277001.67 61.36 138531.51 436.93 50 50.00 54.93 113.64 277001.67 276458.36 61.34 138259.85 436.93 51 51.00 51.16 106.09 276458.36 275464.37 61.32 137762.84 436.92 52 52.00 47.39 98.55 275464.37 274021.40 61.28 137041.34 436.91 53 53.00 43.62 91.01 274021.40 272131.11 61.23 136096.17 436.90 54 54.00 39.91 83.53 272131.11 269798.61 61.18 134929.89 436.88 55 55.00 36.24 76.15 269798.61 267030.90 61.11 133546.00 436.86 56 56.00 32.57 68.80 267030.90 263831.36 61.03 131946.19 436.84 57 57.00 28.89 61.46 263831.36 260201.35 60.93 130131.14 436.82 58 58.00 25.22 54.11 260201.35 256142.32 60.83 128101.58 436.79 59 59.00 21.55 46.77 256142.32 251655.77 60.72 125858.24 436.76 60 60.00 17.88 39.42 251655.77 246743.10 60.59 123401.85 436.73 61 61.00 14.21 32.08 246743.10 241405.69 60.45 120733.07 436.69 62 62.00 10.53 24.74 241405.69 235644.88 60.30 117852.59 436.65 63 63.00 8.67 19.20 235644.88 229570.20 60.15 114815.17 436.61 64 64.00 8.61 17.28 229570.20 223399.21 59.98 111729.60 436.57 Dominion Development Resources, LLC Page 50 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report Name: SWM2, l0yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 66.02 (cfs) Time to Peak (Tp) = 52.00 (min) Time of Base (Tb) = 1315.00 (min) Volume = 10.71 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 438.22 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = Exist Westminister Pond Storage Type = User-Defined Area Maximum Storage = 777428.76 (cu ft) Maximum Discharge = 372.10 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-2 & SWM3, 10yr Peak Flow (Qp) = 210.63 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1297.00 (min) Volume = 10.71 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: • I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 7.77 7.77 0.00 457.40 0.14 228.77 434.82 2 2.00 15.64 23.40 457.40 1819.40 0.56 909.98 434.84 3 3.00 23.62 39.26 1819.40 4065.82 1.25 2033.53 434.88 4 4.00 31.70 55.31 4065.82 7177.01 2.20 3589.60 434.93 5 5.00 39.88 71.58 7177.01 11133.81 3.41 5568.61 435.00 6 6.00 48.16 88.04 11133.81 15911.36 4.98 7958.17 435.04 7 7.00 56.47 104.63 15911.36 21478.81 6.83 10742.82 435.09 8 8.00 64.86 121.33 21478.81 27810.49 8.94 13909.71 435.14 9 9.00 73.34 138.20 27810.49 34886.62 11.29 17448.95 435.20 10 10.00 81.90 155.24 34886.62 42653.21 14.46 21333.83 435.26 Dominion Development Resources, LLC Page 51 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report SWM2, l0yr [Computation of Reservoir Outflow Table of Modified Puls Method) Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 90.40 172.30 42653.21 51039.39 18.02 25528.70 435.33 12 12.00 98.73 189.13 51039.39 59993.06 21.82 30007.44 435.40 13 13.00 107.11 205.84 59993.06 69448.61 26.35 34737.48 435.47 14 14.00 115.54 222.65 69448.61 79349.41 31.21 39690.31 435.55 15 15.00 123.82 239.36 79349.41 89652.19 36.35 44844.27 435.62 16 16.00 132.09 255.91 89652.19 100293.87 42.10 50167.98 435.70 17 17.00 140.34 272.43 100293.87 111227.39 48.01 55637.70 435.78 18 18.00 149.24 289.58 111227.39 122589.44 52.14 61320.79 435.87 19 19.00 158.09 307.33 122589.44 134568.17 55.49 67311.83 435.95 20 20.00 166.85 324.94 134568.17 147256.59 57.93 73657.26 436.04 21 21.00 175.52 342.37 147256.59 160824.24 58.30 80441.27 436.14 22 22.00 184.47 359.99 160824.24 175402.49 58.70 87730.60 436.24 23 23.00 193.31 377.78 175402.49 190999.00 59.13 95529.06 436.35 24 24.00 202.03 395.35 190999.00 207597.63 59.57 103828.60 436.46 25 25.00 210.63 412.66 207597.63 225180.84 60.03 112620.44 436.58 26 26.00 206.25 416.88 225180.84 242961.83 60.49 121511.16 436.70 27 27.00 201.76 408.01 242961.83 260156.40 60.93 130108.67 436.82 28 28.00 197.15 398.90 260156.40 276753.20 61.35 138407.28 436.93 29 29.00 192.43 389.57 276753.20 292741.13 61.75 146401.44 437.04 30 30.00 187.63 380.06 292741.13 308111.49 62.13 154086.81 437.14 31 31.00 182.73 370.36 308111.49 322855.62 62.49 161459.06 437.24 32 32.00 177.70 360.43 322855.62 336961.87 62.83 168512.35 437.33 33 33.00 172.55 350.25 336961.87 350418.01 63.15 175240.58 437.42 34 34.00 167.29 339.85 350418.01 363212.30 63.45 181637.88 437.50 35 35.00 161.92 329.21 363212.30 375333.36 63.74 187698.55 437.58 36 36.00 156.45 318.37 375333.36 386770.75 64.00 193417.37 437.65 . 37 37.00 150.92 307.37 386770.75 397517.59 64.25 198790.92 437.72 38 38.00 145.33 296.26 397517.59 407568.69 64.48 203816.59 437.79 39 39.00 139.73 285.06 407568.69 416921.40 64.70 208493.05 437.85 40 40.00 134.13 273.86 416921.40 425577.72 64.89 212821.30 437.90 41 41.00 128.55 262.68 425577.72 433540.93 65.07 216803.00 437.95 42 42.00 122.98 251.53 433540.93 440814.21 65.23 220439.72 438.00 43 43.00 117.42 240.39 440814.21 447400.79 65.38 223733.09 438.04 44 44.00 111.86 229.28 447400.79 453303.94 65.51 226684.72 438.08 45 45.00 106.32 218.18 453303.94 458526.68 65.63 229296.15 438.11 46 46.00 100.79 207.11 458526.68 463071.99 65.73 231568.86 438.14 47 47.00 95.27 196.05 463071.99 466942.80 65.81 233504.31 438.16 48 48.00 89.75 185.02 466942.80 470142.01 65.88 235103.95 438.18 49 49.00 84.25 174.00 470142.01 472672.48 65.94 236369.21 438.20 50 50.00 78.75 163.00 472672.48 474537.03 65.98 237301.51 438.21 51 51.00 73.26 152.01 474537.03 475738.50 66.01 237902.26 438.22 52 52.00 67.78 141.04 475738.50 476279.67 66.02 238172.84 438.22 53 53.00 62.36 130.14 476279.67 476166.29 66.02 238116.15 438.22 54 54.00 57.00 119.36 476166.29 475406.89 66.00 237736.45 438.22 55 55.00 51.63 108.63 475406.89 474006.66 65.97 237036.31 438.21 56 56.00 46.28 97.91 474006.66 471967.74 65.92 236016.83 438.20 57 57.00 40.92 87.20 471967.74 469292.31 65.86 234679.09 438.18 58 58.00 35.57 76.49 469292.31 465982.46 65.79 233024.13 438.16 59 59.00 30.22 65.79 465982.46 462040.31 65.70 231053.01 438.13 60 60.00 24.88 55.10 462040.31 457467.94 65.60 228766.77 438.10 61 61.00 19.54 44.41 457467.94 452267.42 65.49 226166.46 438.07 62 62.00 14.20 33.74 452267.42 446440.83 65.36 223253.09 438.03 63 63.00 11.44 25.63 446440.83 440144.30 65.22 220104.76 437.99 64 64.00 11.25 22.68 440144.30 433687.72 65.07 216876.40 437.95 Dominion Development Resources, LLC Page 52 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 • Routed Hydrograph Report Name: SWM2, 100yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 72.74 (cfs) Time to Peak (Tp) = 55.00 (min) Time of Base (Tb) = 1330.00 (min) Volume = 15.50 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 440.25 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = Exist Westminister Pond Storage Type = User-Defined Area Maximum Storage = 777428.76 (cu ft) Maximum Discharge = 372.10 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-2 & SWM3, 100yr Peak Flow (Qp) = 316.04 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1313.00 (min) Volume = 15.50 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: . Il = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 11.27 11.27 0.00 663.93 0.20 332.07 434.82 2 2.00 22.70 33.97 663.93 2640.77 0.81 1320.79 434.85 3 3.00 34.27 56.97 2640.77 5901.03 1.81 2951.42 434.91 4 4.00 46.00 80.27 5901.03 10415.95 3.19 5209.57 434.98 5 5.00 57.87 103.87 10415.95 16150.96 5.06 8078.01 435.04 6 6.00 69.79 127.66 16150.96 23063.04 7.36 11535.20 435.10 7 7.00 81.84 151.63 23063.04 31114.30 10.04 15562.17 435.17 8 8.00 94.01 175.85 31114.30 40253.29 13.44 20133.36 435.24 9 9.00 106.22 200.23 40253.29 50392.09 17.74 25204.92 435.32 10 10.00 118.16 224.38 50392.09 61439.53 22.44 30730.98 435.41 Dominion Development Resources, LLC Page 53 (434)984-1599 Luxor Subdivision Westminster Canterbury Pond, SWM #2 Routed Hydrograph Report SWM2, 100yr [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 130.17 248.33 61439.53 73293.15 28.24 36660.70 435.50 12 12.00 142.16 272.34 73293.15 85868.65 34.40 42951.53 435.60 13 13.00 154.06 296.23 85868.65 99084.14 41.45 49562.79 435.69 14 14.00 166.06 320.13 99084.14 112863.85 48.89 56456.37 435.80 15 15.00 179.25 345.31 112863.85 127434.63 53.49 63744.06 435.90 16 16.00 192.42 371.67 127434.63 143052.13 57.81 71554.97 436.01 17 17.00 206.14 398.56 143052.13 159999.76 58.28 80029.02 436.13 18 18.00 219.80 425.94 159999.76 178531.35 58.79 89295.07 436.26 19 19.00 233.30 453.10 178531.35 198629.75 59.33 99344.54 436.40 20 20.00 246.90 480.21 198629.75 220287.53 59.90 110173.72 436.55 21 21.00 260.27 507.17 220287.53 243492.88 60.51 121776.69 436.71 22 22.00 273.41 533.68 243492.88 268214.72 61.14 134137.93 436.87 23 23.00 287.00 560.41 268214.72 294462.85 61.79 147262.32 437.05 24 24.00 301.85 588.84 294462.85 322336.63 62.48 161199.55 437.23 25 25.00 316.04 617.89 322336.63 351869.67 63.19 175966.43 437.43 26 26.00 310.97 627.02 351869.67 381865.43 63.89 190964.66 437.62 27 27.00 305.33 616.31 381865.43 411135.86 64.56 205600.21 437.81 28 28.00 299.17 604.50 411135.86 439618.91 65.21 219842.06 437.99 29 29.00 292.51 591.67 439618.91 467256.98 65.82 233661.40 438.17 30 30.00 285.38 577.89 467256.98 493996.57 66.40 247031.48 438.33 31 31.00 277.84 563.22 493996.57 519787.99 66.95 259927.47 438.49 32 32.00 269.89 547.72 519787.99 544585.13 67.48 272326.31 438.65 33 33.00 261.57 531.46 544585.13 568345.25 67.97 284206.61 438.79 34 34.00 252.90 514.47 568345.25 591028.85 68.43 295548.64 438.93 35 35.00 243.92 496.82 591028.85 612599.21 68.87 306334.04 439.06 36 36.00 234.63 478.54 612599.21 633022.24 69.28 316545.76 439.18 - 37 37.00 225.06 459.68 633022.24 652266.50 69.66 326168.08 439.30 38 38.00 215.33 440.38 652266.50 670308.84 70.01 335189.42 439.41 39 39.00 205.65 420.98 670308.84 687146.13 70.34 343608.23 439.51 40 40.00 196.24 401.89 687146.13 702800.53 70.64 351435.59 439.60 41 41.00 187.98 384.22 702800.53 717360.41 70.91 358715.66 439.68 42 42.00 179.75 367.74 717360.41 730899.46 71.17 365485.32 439.76 43 43.00 171.55 351.30 730899.46 743422.72 71.41 371747.06 439.83 44 44.00 163.36 334.90 743422.72 754935.26 71.62 377503.44 439.90 45 45.00 155.19 318.55 754935.26 765441.94 71.81 382756.88 439.96 46 46.00 147.04 302.23 765441.94 774947.42 71.99 387509.71 440.02 47 47.00 138.91 285.95 774947.42 783456.43 72.14 391764.29 440.07 48 48.00 130.80 269.71 783456.43 790973.59 72.28 395522.93 440.11 49 49.00 122.71 253.51 790973.59 797503.23 72.40 398787.82 440.15 50 50.00 114.63 237.34 797503.23 803049.65 72.50 401561.08 440.18 51 51.00 106.58 221.21 803049.65 807617.07 72.58 403844.83 440.20 52 52.00 98.55 205.13 807617.07 811210.62 72.65 405641.63 440.22 53 53.00 90.60 189.15 811210.62 813839.15 72.70 406955.92 440.24 54 54.00 82.67 173.27 813839.15 815510.22 72.72 407791.47 440.25 55 55.00 74.74 157.41 815510.22 816227.22 72.74 408149.98 440.25 56 56.00 66.83 141.58 816227.22 815993.53 72.73 408033.13 440.25 57 57.00 58.93 125.76 815993.53 814812.50 72.71 407442.61 440.24 58 58.00 51.04 109.97 814812.50 812687.41 72.67 406380.04 440.23 59 59.00 43.16 94.20 812687.41 809621.53 72.62 404847.08 440.22 60 60.00 35.29 78.44 809621.53 805618.15 72.55 402845.35 440.19 61 61.00 27.42 62.71 805618.15 800680.57 72.46 400376.51 440.16 62 62.00 19.57 47.00 800680.57 794811.99 72.35 397442.17 440.13 63 63.00 15.46 35.03 794811.99 788239.24 72.23 394155.74 440.09 64 64.00 15.09 30.55 788239.24 781412.25 72.11 390742.18 440.05 Dominion Development Resources, LLC Page 54 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-1, 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) 120.98 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 5.42 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 5.42 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 2.50 0 0.30 Commercial 9.50 0 0.75 Montessori 5.40 0 0.50 Roads 1.00 0 0.90 Future Uncontained 18.70 0 0.32 Woods/Brush 40.40 0 0.30 Fontana & Avemore 61.50 0 0.30 Existing Town & Country 1.90 0 0.70 Overall Approximation 140.90 NA 0.35 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 26.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.05 (in) Return Period = 2 (yr) Storm Duration = 0.43 (hr) Dominion Development Resources, LLC Page 55 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report DA-1, 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.04 0.00 4.65 2 2.00 0.04 0.08 4.65 9.31 3 3.00 0.04 0.12 4.65 13.96 4 4.00 0.04 0.16 4.65 18.61 5 5.00 0.04 0.20 4.65 23.26 6 6.00 0.04 0.24 4.65 27.92 7 7.00 0.04 0.28 4.65 32.57 8 8.00 0.04 0.32 4.65 37.22 9 9.00 0.04 0.36 4.65 41.88 10 10.00 0.04 0.41 4.65 46.53 11 11.00 0.04 0.45 4.65 51.18 12 12.00 0.04 0.49 4.65 55.83 13 13.00 0.04 0.53 4.65 60.49 14 14.00 0.04 0.57 4.65 65.14 15 15.00 0.04 0.61 4.65 69.79 16 16.00 0.04 0.65 4.65 74.45 17 17.00 0.04 0.69 4.65 79.10 18 18.00 0.04 0.73 4.65 83.75 19 19.00 0.04 0.77 4.65 88.41 20 20.00 0.04 0.81 4.65 93.06 21 21.00 0.04 0.85 4.65 97.71 22 22.00 0.04 0.89 4.65 102.36 23 23.00 0.04 0.93 4.65 107.02 24 24.00 0.04 0.97 4.65 111.67 25 25.00 0.04 1.01 4.65 116.32 - 26 26.00 0.04 1.05 4.65 120.98 27 27.00 0.00 1.05 -3.10 117.87 28 28.00 0.00 1.05 -3.10 114.77 29 29.00 0.00 1.05 -3.10 111.67 30 30.00 0.00 1.05 -3.10 108.57 31 31.00 0.00 1.05 -3.10 105.47 32 32.00 0.00 1.05 -3.10 102.36 33 33.00 0.00 1.05 -3.10 99.26 34 34.00 0.00 1.05 -3.10 96.16 35 35.00 0.00 1.05 -3.10 93.06 36 36.00 0.00 1.05 -3.10 89.96 37 37.00 0.00 1.05 -3.10 86.85 38 38.00 0.00 1.05 -3.10 83.75 39 39.00 0.00 1.05 -3.10 80.65 40 40.00 0.00 1.05 -3.10 77.55 41 41.00 0.00 1.05 -3.10 74.45 42 42.00 0.00 1.05 -3.10 71.34 43 43.00 0.00 1.05 -3.10 68.24 44 44.00 0.00 1.05 -3.10 65.14 45 45.00 0.00 1.05 -3.10 62.04 46 46.00 0.00 1.05 -3.10 58.94 47 47.00 0.00 1.05 -3.10 55.83 48 48.00 0.00 1.05 -3.10 52.73 49 49.00 0.00 1.05 -3.10 49.63 50 50.00 0.00 1.05 -3.10 46.53 51 51.00 0.00 1.05 -3.10 43.43 52 52.00 0.00 1.05 -3.10 40.33 53 53.00 0.00 1.05 -3.10 37.22 Dominion Development Resources, LLC Page 56 (434)984-1599 s Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-1, l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) 175.31 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 7.85 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 7.85 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 2.50 0 0.30 Commercial 9.50 0 0.75 Montessori 5.40 0 0.50 Roads 1.00 0 0.90 Future Uncontained 18.70 0 0.32 Woods/Brush 40.40 0 0.30 Fontana & Avemore 61.50 0 0.30 Existing Town & Country 1.90 0 0.70 Overall Approximation 140.90 NA 0.35 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 26.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.53 (in) Return Period = User Defined (yr) Storm Duration = 0.43 (hr) Dominion Development Resources, LLC Page 57 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report DA-1, l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.06 0.00 6.74 2 2.00 0.06 0.12 6.74 13.49 3 3.00 0.06 0.18 6.74 20.23 4 4.00 0.06 0.23 6.74 26.97 5 5.00 0.06 0.29 6.74 33.71 6 6.00 0.06 0.35 6.74 40.46 7 7.00 0.06 0.41 6.74 47.20 8 8.00 0.06 0.47 6.74 53.94 9 9.00 0.06 0.53 6.74 60.68 10 10.00 0.06 0.59 6.74 67.43 11 11.00 0.06 0.65 6.74 74.17 12 12.00 0.06 0.70 6.74 80.91 13 13.00 0.06 0.76 6.74 87.66 14 14.00 0.06 0.82 6.74 94.40 15 15.00 0.06 0.88 6.74 101.14 16 16.00 0.06 0.94 6.74 107.88 17 17.00 0.06 1.00 6.74 114.63 18 18.00 0.06 1.06 6.74 121.37 19 19.00 0.06 1.12 6.74 128.11 20 20.00 0.06 1.17 6.74 134.85 21 21.00 0.06 1.23 6.74 141.60 22 22.00 0.06 1.29 6.74 148.34 23 23.00 0.06 1.35 6.74 155.08 24 24.00 0.06 1.41 6.74 161.83 25 25.00 0.06 1.47 6.74 168.57 . 26 26.00 0.06 1.53 6.74 175.31 27 27.00 0.00 1.53 -4.50 170.82 28 28.00 0.00 1.53 -4.50 166.32 29 29.00 0.00 1.53 -4.50 161.83 30 30.00 0.00 1.53 -4.50 157.33 31 31.00 0.00 1.53 -4.50 152.83 32 32.00 0.00 1.53 -4.50 148.34 33 33.00 0.00 1.53 -4.50 143.84 34 34.00 0.00 1.53 -4.50 139.35 35 35.00 0.00 1.53 -4.50 134.85 36 36.00 0.00 1.53 -4.50 130.36 37 37.00 0.00 1.53 -4.50 125.86 38 38.00 0.00 1.53 -4.50 121.37 39 39.00 0.00 1.53 -4.50 116.87 40 40.00 0.00 1.53 -4.50 112.38 41 41.00 0.00 1.53 -4.50 107.88 42 42.00 0.00 1.53 -4.50 103.39 43 43.00 0.00 1.53 -4.50 98.89 44 44.00 0.00 1.53 -4.50 94.40 45 45.00 0.00 1.53 -4.50 89.90 46 46.00 0.00 1.53 -4.50 85.41 47 47.00 0.00 1.53 -4.50 80.91 48 48.00 0.00 1.53 -4.50 76.42 49 49.00 0.00 1.53 -4.50 71.92 50 50.00 0.00 1.53 -4.50 67.43 51 51.00 0.00 1.53 -4.50 62.93 52 52.00 0.00 1.53 -4.50 58.44 53 53.00 0.00 1.53 -4.50 53.94 Dominion Development Resources, LLC Page 58 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Pre-Development Hydrograph Report Name: DA-1, 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 257.07 (cfs) Time to Peak (Tp) = 26.00 (min) Time of Base (Tb) = 65.00 (min) Volume = 11.51 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 11.51 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Fontana 2.50 0 0.30 Commercial 9.50 0 0.75 Montessori 5.40 0 0.50 Roads 1.00 0 0.90 Future Uncontained 18.70 0 0.32 Woods/Brush 40.40 0 0.30 Fontana & Avemore 61.50 0 0.30 Existing Town & Country 1.90 0 0.70 Overall Approximation 140.90 NA 0.35 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 26.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 2.24 (in) Return Period = 100 (yr) Storm Duration = 0.43 (hr) Dominion Development Resources,LLC Page 59 (434)984-1599 Luxor Subdivision Stonnwater Management Pond#1 • Pre-Development Hydrograph Report DA-1, 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.09 0.00 9.89 2 2.00 0.09 0.17 9.89 19.77 3 3.00 0.09 0.26 9.89 29.66 4 4.00 0.09 0.34 9.89 39.55 5 5.00 0.09 0.43 9.89 49.44 6 6.00 0.09 0.52 9.89 59.32 7 7.00 0.09 0.60 9.89 69.21 8 8.00 0.09 0.69 9.89 79.10 9 9.00 0.09 0.77 9.89 88.99 10 10.00 0.09 0.86 9.89 98.87 11 11.00 0.09 0.95 9.89 108.76 12 12.00 0.09 1.03 9.89 118.65 13 13.00 0.09 1.12 9.89 128.54 14 14.00 0.09 1.21 9.89 138.42 15 15.00 0.09 1.29 9.89 148.31 16 16.00 0.09 1.38 9.89 158.20 17 17.00 0.09 1.46 9.89 168.09 18 18.00 0.09 1.55 9.89 177.97 19 19.00 0.09 1.64 9.89 187.86 20 20.00 0.09 1.72 9.89 197.75 21 21.00 0.09 1.81 9.89 207.64 22 22.00 0.09 1.89 9.89 217.52 23 23.00 0.09 1.98 9.89 227.41 24 24.00 0.09 2.07 9.89 237.30 25 25.00 0.09 2.15 9.89 247.19 26 26.00 0.09 2.24 9.89 257.07 27 27.00 0.00 2.24 -6.59 250.48 28 28.00 0.00 2.24 -6.59 243.89 29 29.00 0.00 2.24 -6.59 237.30 30 30.00 0.00 2.24 -6.59 230.71 31 31.00 0.00 2.24 -6.59 224.11 32 32.00 0.00 2.24 -6.59 217.52 33 33.00 0.00 2.24 -6.59 210.93 34 34.00 0.00 2.24 -6.59 204.34 35 35.00 0.00 2.24 -6.59 197.75 36 36.00 0.00 2.24 -6.59 191.16 37 37.00 0.00 2.24 -6.59 184.57 38 38.00 0.00 2.24 -6.59 177.97 39 39.00 0.00 2.24 -6.59 171.38 40 40.00 0.00 2.24 -6.59 164.79 41 41.00 0.00 2.24 -6.59 158.20 42 42.00 0.00 2.24 -6.59 151.61 43 43.00 0.00 2.24 -6.59 145.02 44 44.00 0.00 2.24 -6.59 138.42 45 45.00 0.00 2.24 -6.59 131.83 46 46.00 0.00 2.24 -6.59 125.24 47 47.00 0.00 2.24 -6.59 118.65 48 48.00 0.00 2.24 -6.59 112.06 49 49.00 0.00 2.24 -6.59 105.47 50 50.00 0.00 2.24 -6.59 98.87 51 51.00 0.00 2.24 -6.59 92.28 52 52.00 0.00 2.24 -6.59 85.69 53 53.00 0.00 2.24 -6.59 79.10 Dominion Development Resources,LLC Page 60 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-Fontana, 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 32.05 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 0.88 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 0.88 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef <None> Overall Approximation 32.85 NA 0.30 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 16.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 0.86 (in) Return Period = 2 (yr) Storm Duration = 0.27 (hr) Dominion Development Resources,LLC Page 61 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 • Pre-Development Hydrograph Report DA-Fontana, 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.05 0.00 2.00 2 2.00 0.05 0.11 2.00 4.01 3 3.00 0.05 0.16 2.00 6.01 4 4.00 0.05 0.22 2.00 8.01 5 5.00 0.05 0.27 2.00 10.01 6 6.00 0.05 0.32 2.00 12.02 7 7.00 0.05 0.38 2.00 14.02 8 8.00 0.05 0.43 2.00 16.02 9 9.00 0.05 0.48 2.00 18.03 10 10.00 0.05 0.54 2.00 20.03 11 11.00 0.05 0.59 2.00 22.03 12 12.00 0.05 0.65 2.00 24.04 13 13.00 0.05 0.70 2.00 26.04 14 14.00 0.05 0.75 2.00 28.04 15 15.00 0.05 0.81 2.00 30.04 16 16.00 0.05 0.86 2.00 32.05 17 17.00 0.00 0.86 -1.34 30.71 18 18.00 0.00 0.86 -1.34 29.38 19 19.00 0.00 0.86 -1.34 28.04 20 20.00 0.00 0.86 -1.34 26.71 21 21.00 0.00 0.86 -1.34 25.37 22 22.00 0.00 0.86 -1.34 24.04 23 23.00 0.00 0.86 -1.34 22.70 24 24.00 0.00 0.86 -1.34 21.36 25 25.00 0.00 0.86 -1.34 20.03 - 26 26.00 0.00 0.86 -1.34 18.69 27 27.00 0.00 0.86 -1.34 17.36 28 28.00 0.00 0.86 -1.34 16.02 29 29.00 0.00 0.86 -1.34 14.69 30 30.00 0.00 0.86 -1.34 13.35 31 31.00 0.00 0.86 -1.34 12.02 32 32.00 0.00 0.86 -1.34 10.68 33 33.00 0.00 0.86 -1.34 9.35 34 34.00 0.00 0.86 -1.34 8.01 35 35.00 0.00 0.86 -1.34 6.68 36 36.00 0.00 0.86 -1.34 5.34 37 37.00 0.00 0.86 -1.34 4.01 38 38.00 0.00 0.86 -1.34 2.67 39 39.00 0.00 0.86 -1.34 1.34 40 40.00 0.00 0.86 -1.34 0.00 Dominion Development Resources, LLC Page 62 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Pre-Development Hydrograph Report Name: DA-Fontana, l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 45.35 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 1.25 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.25 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef <None> Overall Approximation 32.85 NA 0.30 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 16.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.22 (in) Return Period = User Defined (yr) Storm Duration = 0.27 (hr) Dominion Development Resources, LLC Page 63 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report DA-Fontana, l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.08 0.00 2.83 2 2.00 0.08 0.15 2.83 5.67 3 3.00 0.08 0.23 2.83 8.50 4 4.00 0.08 0.30 2.83 11.34 5 5.00 0.08 0.38 2.83 14.17 6 6.00 0.08 0.46 2.83 17.01 7 7.00 0.08 0.53 2.83 19.84 8 8.00 0.08 0.61 2.83 22.67 9 9.00 0.08 0.68 2.83 25.51 10 10.00 0.08 0.76 2.83 28.34 11 11.00 0.08 0.84 2.83 31.18 12 12.00 0.08 0.91 2.83 34.01 13 13.00 0.08 0.99 2.83 36.84 14 14.00 0.08 1.06 2.83 39.68 15 15.00 0.08 1.14 2.83 42.51 16 16.00 0.08 1.22 2.83 45.35 17 17.00 0.00 1.22 -1.89 43.46 18 18.00 0.00 1.22 -1.89 41.57 19 19.00 0.00 1.22 -1.89 39.68 20 20.00 0.00 1.22 -1.89 37.79 21 21.00 0.00 1.22 -1.89 35.90 22 22.00 0.00 1.22 -1.89 34.01 23 23.00 0.00 1.22 -1.89 32.12 24 24.00 0.00 1.22 -1.89 30.23 25 25.00 0.00 1.22 -1.89 28.34 26 26.00 0.00 1.22 -1.89 26.45 27 27.00 0.00 1.22 -1.89 24.56 28 28.00 0.00 1.22 -1.89 22.67 29 29.00 0.00 1.22 -1.89 20.78 30 30.00 0.00 1.22 -1.89 18.89 31 31.00 0.00 1.22 -1.89 17.01 32 32.00 0.00 1.22 -1.89 15.12 33 33.00 0.00 1.22 -1.89 13.23 34 34.00 0.00 1.22 -1.89 11.34 35 35.00 0.00 1.22 -1.89 9.45 36 36.00 0.00 1.22 -1.89 7.56 37 37.00 0.00 1.22 -1.89 5.67 38 38.00 0.00 1.22 -1.89 3.78 39 39.00 0.00 1.22 -1.89 1.89 40 40.00 0.00 1.22 -1.89 0.00 Dominion Development Resources, LLC Page 64 (434)984-1599 5 Luxor Subdivision Stormwater Management Pond#1 Pre-Development Hydrograph Report Name: DA-Fontana, 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 65.68 (cfs) Time to Peak (Tp) = 16.00 (min) Time of Base (Tb) = 40.00 (min) Volume = 1.81 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.81 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef <None> Overall Approximation 32.90 NA 0.30 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 16.00 (min) 0 [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.76 (in) Return Period = 100 (yr) Storm Duration = 0.27 (hr) Dominion Development Resources,LLC Page 65 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Pre-Development Hydrograph Report DA-Fontana, 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.11 0.00 4.10 2 2.00 0.11 0.22 4.10 8.21 3 3.00 0.11 0.33 4.10 12.31 4 4.00 0.11 0.44 4.10 16.42 5 5.00 0.11 0.55 4.10 20.52 6 6.00 0.11 0.66 4.10 24.63 7 7.00 0.11 0.77 4.10 28.73 8 8.00 0.11 0.88 4.10 32.84 9 9.00 0.11 0.99 4.10 36.94 10 10.00 0.11 1.10 4.10 41.05 11 11.00 0.11 1.21 4.10 45.15 12 12.00 0.11 1.32 4.10 49.26 13 13.00 0.11 1.43 4.10 53.36 14 14.00 0.11 1.54 4.10 57.47 15 15.00 0.11 1.65 4.10 61.57 16 16.00 0.11 1.76 4.10 65.68 17 17.00 0.00 1.76 -2.74 62.94 18 18.00 0.00 1.76 -2.74 60.20 19 19.00 0.00 1.76 -2.74 57.47 20 20.00 0.00 1.76 -2.74 54.73 21 21.00 0.00 1.76 -2.74 51.99 22 22.00 0.00 1.76 -2.74 49.26 23 23.00 0.00 1.76 -2.74 46.52 24 24.00 0.00 1.76 -2.74 43.78 25 25.00 0.00 1.76 -2.74 41.05 26 26.00 0.00 1.76 -2.74 38.31 27 27.00 0.00 1.76 -2.74 35.57 28 28.00 0.00 1.76 -2.74 32.84 29 29.00 0.00 1.76 -2.74 30.10 30 30.00 0.00 1.76 -2.74 27.36 31 31.00 0.00 1.76 -2.74 24.63 32 32.00 0.00 1.76 -2.74 21.89 33 33.00 0.00 1.76 -2.74 19.16 34 34.00 0.00 1.76 -2.74 16.42 35 35.00 0.00 1.76 -2.74 13.68 36 36.00 0.00 1.76 -2.74 10.95 37 37.00 0.00 1.76 -2.74 8.21 38 38.00 0.00 1.76 -2.74 5.47 39 39.00 0.00 1.76 -2.74 2.74 40 40.00 0.00 1.76 -2.74 0.00 Dominion Development Resources, LLC Page 66 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 78.67 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 2.71 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 2.71 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavilions-I 6.80 0 0.55 Commercial 21.20 0 0.85 Existing Fontana 2.20 0 0.50 Town & Country 2.15 0 0.70 Undeveloped 4.60 0 0.55 Overall Approximation 36.95 NA 0.73 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Aistribution Type = Synthetic Total Precipitation = 0.97 (in) Return Period = 2 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 67 (434)984-1599 r Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report DA-1, Post 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.05 0.00 3.93 2 2.00 0.05 0.10 3.93 7.87 3 3.00 0.05 0.15 3.93 11.80 4 4.00 0.05 0.19 3.93 15.73 5 5.00 0.05 0.24 3.93 19.67 6 6.00 0.05 0.29 3.93 23.60 7 7.00 0.05 0.34 3.93 27.54 8 8.00 0.05 0.39 3.93 31.47 9 9.00 0.05 0.44 3.93 35.40 10 10.00 0.05 0.48 3.93 39.34 11 11.00 0.05 0.53 3.93 43.27 12 12.00 0.05 0.58 3.93 47.20 13 13.00 0.05 0.63 3.93 51.14 14 14.00 0.05 0.68 3.93 55.07 15 15.00 0.05 0.73 3.93 59.01 16 16.00 0.05 0.77 3.93 62.94 17 17.00 0.05 0.82 3.93 66.87 18 18.00 0.05 0.87 3.93 70.81 19 19.00 0.05 0.92 3.93 74.74 20 20.00 0.05 0.97 3.93 78.67 21 21.00 0.00 0.97 -2.62 76.05 22 22.00 0.00 0.97 -2.62 73.43 23 23.00 0.00 0.97 -2.62 70.81 24 24.00 0.00 0.97 -2.62 68.18 25 25.00 0.00 0.97 -2.62 65.56 26 26.00 0.00 0.97 -2.62 62.94 27 27.00 0.00 0.97 -2.62 60.32 28 28.00 0.00 0.97 -2.62 57.69 29 29.00 0.00 0.97 -2.62 55.07 30 30.00 0.00 0.97 -2.62 52.45 31 31.00 0.00 0.97 -2.62 49.83 32 32.00 0.00 0.97 -2.62 47.20 33 33.00 0.00 0.97 -2.62 44.58 34 34.00 0.00 0.97 -2.62 41.96 35 35.00 0.00 0.97 -2.62 39.34 36 36.00 0.00 0.97 -2.62 36.71 37 37.00 0.00 0.97 -2.62 34.09 38 38.00 0.00 0.97 -2.62 31.47 39 39.00 0.00 0.97 -2.62 28.85 40 40.00 0.00 0.97 -2.62 26.22 41 41.00 0.00 0.97 -2.62 23.60 42 42.00 0.00 0.97 -2.62 20.98 43 43.00 0.00 0.97 -2.62 18.36 44 44.00 0.00 0.97 -2.62 15.73 45 45.00 0.00 0.97 -2.62 13.11 46 46.00 0.00 0.97 -2.62 10.49 47 47.00 0.00 0.97 -2.62 7.87 48 48.00 0.00 0.97 -2.62 5.24 49 49.00 0.00 0.97 -2.62 2.62 50 50.00 0.00 0.97 -2.62 0.00 Dominion Development Resources, LLC Page 68 (434)984-1599 0 Luxor Subdivision 4 Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 110.91 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 3.82 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 3.82 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavlions-I 6.80 0 0.55 Commercial 21.20 0 0.85 Existing Fontana 2.20 0 0.50 Town & Country 2.15 0 0.70 Undeveloped 4.60 0 0.55 Overall Approximation 36.95 NA 0.73 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.36 (in) Return Period = User Defined (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 69 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report DA-1, Post l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.07 0.00 5.55 2 2.00 0.07 0.14 5.55 11.09 3 3.00 0.07 0.20 5.55 16.64 4 4.00 0.07 0.27 5.55 22.18 5 5.00 0.07 0.34 5.55 27.73 6 6.00 0.07 0.41 5.55 33.27 7 7.00 0.07 0.48 5.55 38.82 8 8.00 0.07 0.55 5.55 44.37 9 9.00 0.07 0.61 5.55 49.91 10 10.00 0.07 0.68 5.55 55.46 11 11.00 0.07 0.75 5.55 61.00 12 12.00 0.07 0.82 5.55 66.55 13 13.00 0.07 0.89 5.55 72.09 14 14.00 0.07 0.95 5.55 77.64 15 15.00 0.07 1.02 5.55 83.18 16 16.00 0.07 1.09 5.55 88.73 17 17.00 0.07 1.16 5.55 94.28 18 18.00 0.07 1.23 5.55 99.82 19 19.00 0.07 1.30 5.55 105.37 20 20.00 0.07 1.36 5.55 110.91 21 21.00 0.00 1.36 -3.70 107.22 22 22.00 0.00 1.36 -3.70 103.52 23 23.00 0.00 1.36 -3.70 99.82 24 24.00 0.00 1.36 -3.70 96.12 25 25.00 0.00 1.36 -3.70 92.43 . 26 26.00 0.00 1.36 -3.70 88.73 27 27.00 0.00 1.36 -3.70 85.03 28 28.00 0.00 1.36 -3.70 81.34 29 29.00 0.00 1.36 -3.70 77.64 30 30.00 0.00 1.36 -3.70 73.94 31 31.00 0.00 1.36 -3.70 70.24 32 32.00 0.00 1.36 -3.70 66.55 33 33.00 0.00 1.36 -3.70 62.85 34 34.00 0.00 1.36 -3.70 59.15 35 35.00 0.00 1.36 -3.70 55.46 36 36.00 0.00 1.36 -3.70 51.76 37 37.00 0.00 1.36 -3.70 48.06 38 38.00 0.00 1.36 -3.70 44.37 39 39.00 0.00 1.36 -3.70 40.67 40 40.00 0.00 1.36 -3.70 36.97 41 41.00 0.00 1.36 -3.70 33.27 42 42.00 0.00 1.36 -3.70 29.58 43 43.00 0.00 1.36 -3.70 25.88 44 44.00 0.00 1.36 -3.70 22.18 45 45.00 0.00 1.36 -3.70 18.49 46 46.00 0.00 1.36 -3.70 14.79 47 47.00 0.00 1.36 -3.70 11.09 48 48.00 0.00 1.36 -3.70 7.39 49 49.00 0.00 1.36 -3.70 3.70 50 50.00 0.00 1.36 -3.70 0.00 Dominion Development Resources, LLC Page 70 (434)984-1599 r • Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-1, Post 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 160.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 5.51 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 5.51 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Pavilions-I 6.80 0 0.55 Commercial 21.20 0 0.85 Existing Fontana 2.20 0 0.50 Town & Country 2.15 0 0.70 Undeveloped 4.60 0 0.55 Overall Approximation 36.95 NA 0.73 • [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.97 (in) Return Period = 100 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 71 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Post-Development Hydrograph Report DA-1, Post 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.10 0.00 8.01 2 2.00 0.10 0.20 8.01 16.01 3 3.00 0.10 0.30 8.01 24.02 4 4.00 0.10 0.39 8.01 32.02 5 5.00 0.10 0.49 8.01 40.03 6 6.00 0.10 0.59 8.01 48.04 7 7.00 0.10 0.69 8.01 56.04 8 8.00 0.10 0.79 8.01 64.05 9 9.00 0.10 0.89 8.01 72.05 10 10.00 0.10 0.98 8.01 80.06 11 11.00 0.10 1.08 8.01 88.07 12 12.00 0.10 1.18 8.01 96.07 13 13.00 0.10 1.28 8.01 104.08 14 14.00 0.10 1.38 8.01 112.08 15 15.00 0.10 1.48 8.01 120.09 16 16.00 0.10 1.58 8.01 128.10 17 17.00 0.10 1.67 8.01 136.10 18 18.00 0.10 1.77 8.01 144.11 19 19.00 0.10 1.87 8.01 152.11 20 20.00 0.10 1.97 8.01 160.12 21 21.00 0.00 1.97 -5.34 154.78 22 22.00 0.00 1.97 -5.34 149.44 23 23.00 0.00 1.97 -5.34 144.11 24 24.00 0.00 1.97 -5.34 138.77 25 25.00 0.00 1.97 -5.34 133.43 . 26 26.00 0.00 1.97 -5.34 128.10 27 27.00 0.00 1.97 -5.34 122.76 28 28.00 0.00 1.97 -5.34 117.42 29 29.00 0.00 1.97 -5.34 112.08 30 30.00 0.00 1.97 -5.34 106.75 31 31.00 0.00 1.97 -5.34 101.41 32 32.00 0.00 1.97 -5.34 96.07 33 33.00 0.00 1.97 -5.34 90.73 34 34.00 0.00 1.97 -5.34 85.40 35 35.00 0.00 1.97 -5.34 80.06 36 36.00 0.00 1.97 -5.34 74.72 37 37.00 0.00 1.97 -5.34 69.39 38 38.00 0.00 1.97 -5.34 64.05 39 39.00 0.00 1.97 -5.34 58.71 40 40.00 0.00 1.97 -5.34 53.37 41 41.00 0.00 1.97 -5.34 48.04 42 42.00 0.00 1.97 -5.34 42.70 43 43.00 0.00 1.97 -5.34 37.36 44 44.00 0.00 1.97 -5.34 32.02 45 45.00 0.00 1.97 -5.34 26.69 46 46.00 0.00 1.97 -5.34 21.35 47 47.00 0.00 1.97 -5.34 16.01 48 48.00 0.00 1.97 -5.34 10.67 49 49.00 0.00 1.97 -5.34 5.34 50 50.00 0.00 1.97 -5.34 0.00 Dominion Development Resources, LLC Page 72 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 • Post-Development Hydrograph Report Name: DA-Fontana Pond, 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 56.18 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 1.45 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.45 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area al Runoff Coef 1/2acre Lots 32.85 0 0.50 Overall Approximation 32.85 NA 0.50 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 0.85 (in) Return Period = 2 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 73 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report DA-Fontana Pond, 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.06 0.00 3.75 2 2.00 0.06 0.11 3.75 7.49 3 3.00 0.06 0.17 3.75 11.24 4 4.00 0.06 0.23 3.75 14.98 5 5.00 0.06 0.28 3.75 18.73 6 6.00 0.06 0.34 3.75 22.47 7 7.00 0.06 0.40 3.75 26.22 8 8.00 0.06 0.45 3.75 29.96 9 9.00 0.06 0.51 3.75 33.71 10 10.00 0.06 0.57 3.75 37.46 11 11.00 0.06 0.62 3.75 41.20 12 12.00 0.06 0.68 3.75 44.95 13 13.00 0.06 0.74 3.75 48.69 14 14.00 0.06 0.79 3.75 52.44 15 15.00 0.06 0.85 3.75 56.18 16 16.00 0.00 0.85 -2.50 53.69 17 17.00 0.00 0.85 -2.50 51.19 18 18.00 0.00 0.85 -2.50 48.69 19 19.00 0.00 0.85 -2.50 46.20 20 20.00 0.00 0.85 -2.50 43.70 21 21.00 0.00 0.85 -2.50 41.20 22 22.00 0.00 0.85 -2.50 38.70 23 23.00 0.00 0.85 -2.50 36.21 24 24.00 0.00 0.85 -2.50 33.71 25 25.00 0.00 0.85 -2.50 31.21 • 26 26.00 0.00 0.85 -2.50 28.72 27 27.00 0.00 0.85 -2.50 26.22 28 28.00 0.00 0.85 -2.50 23.72 29 29.00 0.00 0.85 -2.50 21.22 30 30.00 0.00 0.85 -2.50 18.73 31 31.00 0.00 0.85 -2.50 16.23 32 32.00 0.00 0.85 -2.50 13.73 33 33.00 0.00 0.85 -2.50 11.24 34 34.00 0.00 0.85 -2.50 8.74 35 35.00 0.00 0.85 -2.50 6.24 36 36.00 0.00 0.85 -2.50 3.75 37 37.00 0.00 0.85 -2.50 1.25 38 37.50 0.00 0.85 -1.25 0.00 Dominion Development Resources, LLC Page 74 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-Fontana Pond, l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 78.15 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.02 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 2.02 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef 1/2acre Lots 32.85 0 0.50 Overall Approximation 32.85 NA 0.50 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.18 (in) Return Period = User Defined (yr) Storm Duration = 0.25 (hr) Dominion Development Resources,LLC Page 75 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 s. Post-Development Hydrograph Report DA-Fontana Pond, l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.08 0.00 5.21 2 2.00 0.08 0.16 5.21 10.42 3 3.00 0.08 0.24 5.21 15.63 4 4.00 0.08 0.31 5.21 20.84 5 5.00 0.08 0.39 5.21 26.05 6 6.00 0.08 0.47 5.21 31.26 7 7.00 0.08 0.55 5.21 36.47 8 8.00 0.08 0.63 5.21 41.68 9 9.00 0.08 0.71 5.21 46.89 10 10.00 0.08 0.79 5.21 52.10 11 11.00 0.08 0.87 5.21 57.31 12 12.00 0.08 0.94 5.21 62.52 13 13.00 0.08 1.02 5.21 67.73 14 14.00 0.08 1.10 5.21 72.94 15 15.00 0.08 1.18 5.21 78.15 16 16.00 0.00 1.18 -3.47 74.68 17 17.00 0.00 1.18 -3.47 71.20 18 18.00 0.00 1.18 -3.47 67.73 19 19.00 0.00 1.18 -3.47 64.26 20 20.00 0.00 1.18 -3.47 60.78 21 21.00 0.00 1.18 -3.47 57.31 22 22.00 0.00 1.18 -3.47 53.84 23 23.00 0.00 1.18 -3.47 50.36 24 24.00 0.00 1.18 -3.47 46.89 25 25.00 0.00 1.18 -3.47 43.42 . 26 26.00 0.00 1.18 -3.47 39.94 27 27.00 0.00 1.18 -3.47 36.47 28 28.00 0.00 1.18 -3.47 33.00 29 29.00 0.00 1.18 -3.47 29.52 30 30.00 0.00 1.18 -3.47 26.05 31 31.00 0.00 1.18 -3.47 22.58 32 32.00 0.00 1.18 -3.47 19.10 33 33.00 0.00 1.18 -3.47 15.63 34 34.00 0.00 1.18 -3.47 12.16 35 35.00 0.00 1.18 -3.47 8.68 36 36.00 0.00 1.18 -3.47 5.21 37 37.00 0.00 1.18 -3.47 1.74 38 37.50 0.00 1.18 -1.74 0.00 Dominion Development Resources,LLC Page 76 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report Name: DA-Fontana Pond, 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 111.96 (cfs) Time to Peak (Tp) = 15.00 (min) Time of Base (Tb) = 37.50 (min) Volume = 2.89 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 2.89 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef 1/2acre Lots 32.85 0 0.50 Overall Approximation 32.85 NA 0.50 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 15.00 (min) . [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.69 (in) Return Period = 100 (yr) Storm Duration = 0.25 (hr) Dominion Development Resources, LLC Page 77 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Post-Development Hydrograph Report DA-Fontana Pond, 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.11 0.00 7.46 2 2.00 0.11 0.23 7.46 14.93 3 3.00 0.11 0.34 7.46 22.39 4 4.00 0.11 0.45 7.46 29.86 5 5.00 0.11 0.56 7.46 37.32 6 6.00 0.11 0.68 7.46 44.79 7 7.00 0.11 0.79 7.46 52.25 8 8.00 0.11 0.90 7.46 59.71 9 9.00 0.11 1.01 7.46 67.18 10 10.00 0.11 1.13 7.46 74.64 11 11.00 0.11 1.24 7.46 82.11 12 12.00 0.11 1.35 7.46 89.57 13 13.00 0.11 1.46 7.46 97.04 14 14.00 0.11 1.58 7.46 104.50 15 15.00 0.11 1.69 7.46 111.96 16 16.00 0.00 1.69 -4.98 106.99 17 17.00 0.00 1.69 -4.98 102.01 18 18.00 0.00 1.69 -4.98 97.04 19 19.00 0.00 1.69 -4.98 92.06 20 20.00 0.00 1.69 -4.98 87.08 21 21.00 0.00 1.69 -4.98 82.11 22 22.00 0.00 1.69 -4.98 77.13 23 23.00 0.00 1.69 -4.98 72.15 24 24.00 0.00 1.69 -4.98 67.18 25 25.00 0.00 1.69 -4.98 62.20 26 26.00 0.00 1.69 -4.98 57.23 27 27.00 0.00 1.69 -4.98 52.25 28 28.00 0.00 1.69 -4.98 47.27 29 29.00 0.00 1.69 -4.98 42.30 30 30.00 0.00 1.69 -4.98 37.32 31 31.00 0.00 1.69 -4.98 32.35 32 32.00 0.00 1.69 -4.98 27.37 33 33.00 0.00 1.69 -4.98 22.39 34 34.00 0.00 1.69 -4.98 17.42 35 35.00 0.00 1.69 -4.98 12.44 36 36.00 0.00 1.69 -4.98 7.46 37 37.00 0.00 1.69 -4.98 2.49 38 37.50 0.00 1.69 -2.49 0.00 Dominion Development Resources,LLC Page 78 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 • Combined Hydrograph Report Name: DA-Fontana Pond & DA-1 & SWM2, 2yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 167.19 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1292.00 (min) Volume = 11.72 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: DA-Fontana Pond, 2yr Type: Modified Rational Peak Flow (Qp) = 56.18 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post 2yr Type: Modified Rational Peak Flow (Qp) = 78.67 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Name: SWM2, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 61.36 (cfs) Time to Peak (Tp) = 48.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] . Interval Time Outflow (min) (cfs) 1 1.00 7.78 2 2.00 15.75 3 3.00 23.91 4 4.00 32.26 5 5.00 40.79 6 6.00 49.50 7 7.00 58.47 8 8.00 67.63 9 9.00 76.97 10 10.00 86.48 11 11.00 96.16 12 12.00 106.55 13 13.00 117.14 14 14.00 127.88 15 15.00 138.93 16 16.00 144.20 17 17.00 149.59 18 18.00 155.11 19 19.00 161.11 20 20.00 167.19 21 21.00 166.78 22 22.00 164.38 23 23.00 161.88 24 24.00 159.48 Dominion Development Resources, LLC Page 79 (434)984-1599 Luxor Subdivision Stonnwater Management Pond#1 Combined Hydrograph Report DA-Fontana Pond & DA-1 & SW142, 2yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 25 25.00 154.84 26 26.00 150.01 27 27.00 145.16 28 28.00 140.30 29 29.00 135.43 30 30.00 130.54 31 31.00 125.64 32 32.00 120.72 33 33.00 115.79 34 34.00 110.86 35 35.00 105.90 36 36.00 100.93 37 37.00 95.96 38 38.00 92.21 39 39.00 89.71 40 40.00 87.19 41 41.00 84.66 42 42.00 82.11 43 43.00 79.56 44 44.00 76.99 45 45.00 74.41 46 46.00 71.82 47 47.00 69.22 48 48.00 66.60 49 49.00 63.98 50 50.00 61.34 • 51 51.00 61.32 52 52.00 61.28 53 53.00 61.23 54 54.00 61.18 55 55.00 61.11 56 56.00 61.03 57 57.00 60.93 58 58.00 60.83 59 59.00 60.72 60 60.00 60.59 61 61.00 60.45 62 62.00 60.30 63 63.00 60.15 64 64.00 59.98 65 65.00 59.82 66 66.00 59.66 67 67.00 59.50 68 68.00 59.34 69 69.00 59.17 70 70.00 59.01 71 71.00 58.84 72 72.00 58.68 73 73.00 58.51 74 74.00 58.35 75 75.00 58.18 76 76.00 58.01 77 77.00 57.85 78 78.00 56.57 Dominion Development Resources, LLC Page 80 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: DA-Fontana Pond & DA-1 & SWM2, l0yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 229.63 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1315.00 (min) Volume = 16.55 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: DA-Fontana Pond, l0yr Type: Modified Rational Peak Flow (Qp) = 78.15 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post l0yr Type: Modified Rational Peak Flow (Qp) = 110.91 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) Name: SWM2, l0yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 66.02 (cfs) Time to Peak (Tp) = 52.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 10.90 2 2.00 22.07 3 3.00 33.51 4 4.00 45.22 5 5.00 57.19 6 6.00 69.51 7 7.00 82.12 8 8.00 94.98 9 9.00 108.09 10 10.00 122.01 11 11.00 136.33 12 12.00 150.89 13 13.00 166.18 14 14.00 181.79 15 15.00 197.69 16 16.00 205.51 17 17.00 213.49 18 18.00 219.69 19 19.00 225.12 20 20.00 229.63 21 21.00 222.83 22 22.00 216.06 23 23.00 209.31 24 24.00 202.58 25 25.00 195.88 Dominion Development Resources, LLC Page 81 (434)984-1599 • Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report DA-Fontana Pond & DA-1 & SWM2, l0yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 26 26.00 189.16 27 27.00 182.44 28 28.00 175.68 29 29.00 168.91 30 30.00 162.12 31 31.00 155.31 32 32.00 148.48 33 33.00 141.63 34 34.00 134.76 35 35.00 127.88 36 36.00 120.97 37 37.00 114.05 38 38.00 108.85 39 39.00 105.36 40 40.00 101.86 41 41.00 98.34 42 42.00 94.81 43 43.00 91.26 44 44.00 87.69 45 45.00 84.11 46 46.00 80.52 47 47.00 76.90 48 48.00 73.28 • 49 49.00 69.64 50 50.00 65.98 51 51.00 66.01 52 52.00 66.02 53 53.00 66.02 54 54.00 66.00 55 55.00 65.97 56 56.00 65.92 57 57.00 65.86 58 58.00 65.79 59 59.00 65.70 60 60.00 65.60 61 61.00 65.49 62 62.00 65.36 63 63.00 65.22 64 64.00 65.07 65 65.00 64.93 66 66.00 64.78 67 67.00 64.64 68 68.00 64.49 69 69.00 64.34 70 70.00 64.19 71 71.00 64.04 72 72.00 63.89 73 73.00 63.74 74 74.00 63.59 75 75.00 63.43 76 76.00 63.28 77 77.00 63.13 78 78.00 62.97 79 79.00 62.82 Dominion Development Resources, LLC Page 82 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: DA-Fontana Pond & DA-1 & SWM2, 100yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 307.10 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1330.00 (min) Volume = 23.91 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: SWM2, 100yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 72.74 (cfs) Time to Peak (Tp) = 55.00 (min) Time Step = 1.00 (min) Name: DA-Fontana Pond, 100yr Type: Modified Rational Peak Flow (Qp) = 111.96 (cfs) Time to Peak (Tp) = 15.00 (min) Time Step = 1.00 (min) Name: DA-1, Post 100yr Type: Modified Rational Peak Flow (Qp) = 160.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 15.67 2 2.00 31.75 3 3.00 48.22 4 4.00 65.07 5 5.00 82.41 6 6.00 100.18 7 7.00 118.33 8 8.00 137.20 9 9.00 156.98 10 10.00 177.14 11 11.00 198.41 12 12.00 220.05 13 13.00 242.56 14 14.00 265.48 15 15.00 285.55 16 16.00 292.90 17 17.00 296.39 18 18.00 299.93 19 19.00 303.50 20 20.00 307.10 21 21.00 297.39 22 22.00 287.71 23 23.00 278.05 24 24.00 268.42 25 25.00 258.82 Dominion Development Resources, LLC Page 83 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report DA-Fontana Pond & DA-1 & SWM2, 100yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 26 26.00 249.21 27 27.00 239.57 28 28.00 229.90 29 29.00 220.20 30 30.00 210.47 31 31.00 200.71 32 32.00 190.92 33 33.00 181.10 34 34.00 171.25 35 35.00 161.37 36 36.00 151.47 37 37.00 141.53 38 38.00 134.06 39 39.00 129.05 40 40.00 124.01 41 41.00 118.95 42 42.00 113.87 43 43.00 108.77 44 44.00 103.64 45 45.00 98.50 46 46.00 93.34 47 47.00 88.16 48 48.00 82.96 49 49.00 77.74 50 50.00 72.50 51 51.00 72.58 > 52 52.00 72.65 53 53.00 72.70 54 54.00 72.72 55 55.00 72.74 56 56.00 72.73 57 57.00 72.71 58 58.00 72.67 59 59.00 72.62 60 60.00 72.55 61 61.00 72.46 62 62.00 72.35 63 63.00 72.23 64 64.00 72.11 65 65.00 71.98 66 66.00 71.86 67 67.00 71.73 68 68.00 71.60 69 69.00 71.47 70 70.00 71.34 71 71.00 71.21 72 72.00 71.08 73 73.00 70.94 74 74.00 70.81 75 75.00 70.68 76 76.00 70.54 77 77.00 70.41 78 78.00 70.27 79 79.00 70.14 Dominion Development Resources,LLC Page 84 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Outlet Structure Report Structure Number : 1 Type : Stand Pipe Name : SWM #1 Riser [RATING CURVE LIMIT] Minimum Elevation = 402.00 (ft) Maximum Elevation = 422.00 (ft) Elevation Increment = 0.25 (ft) [STAND PIPE INFORMATION] [ORIFICE INFORMATION] Diameter = 6.00 (ft) Crest Length = 18.85 (ft) Effective Crest Length = 18.85 (ft) Orifice Coefficient = 0.70 Fractional Open Area = 0.83 [ORIFICE EQUATION] Q = Co*A( (2gh)/k)A0.5 [DEFINITIONS] Co = Orifice Coefficient A = Wetted Area, (sq ft) [WEIR INFORMATION] Crest Elevation = 417.80 (ft) Weir Coefficient = 3.33 Exponential = 1.50 [WEIR EQUATION] Q = Cw * L * HAexp [DEFINITIONS] Cw = Weir Coefficient H = Headwater depth above inlet control section invert ft L = Crest lenght ft [OPTIONAL ORIFICE INFORMATION] Structure Number : 1 Type : Rectangular Orifice [OPTIONAL ORIFICE INFORMATION] Height = 1.75 (ft) Width = 2.00 (ft) Invert Elevation = 415.00 (ft) Orifice Coefficient = 0.60 Number of Openings = 4 [ORIFICE EQUATION] Q = Co*A((2gh)/k)A0.5 [DEFINITIONS] Co = Orifice Coefficient A = Wetted Area, (cfs) k = 1 Dominion Development Resources, LLC Page 85 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Outlet Structure Report SWM #1 Riser [CULVERT INFORMATION] Type : Circular Concrete - Square Edge with Headwall [OUTLET STRUCTURE INFORMATION] Diameter = 60.00 (in) Invert Elevation = 402.00 (ft) Pipe Length = 150.00 (ft) Slope = 0.03 Manning's n Value = 0.01 Orifice Coefficient = 0.60 Tailwater Elevation = 0.00 (ft) Number of Barrels = 1 [UNSUBMERGED EQUATION] H/Diam = Hc/Diam+K*(Q/(A*Diam"0.5))'M-0.5*S Coefficient K = 0.01 Coefficient M = 2.00 Q Maximum = 153.67 [SUBMERGED EQUATION] H/Diam = c*(Q/(A*Diam"0.5) )A2+Y-0.5*S Coefficient c = 0.04 Coefficient Y = 0.67 Q Minimum = 175.62 [DEFINITIONS] H = Headwater depth above inlet control section invert, (ft) ` Diam = Interior height of culvert barrel, (ft) He = Specific head at critical depth (dc+Vc"2/2g) , (ft) Q = Discharge, (cfs) • A = Full cross sectional area of culvert barrel, (sq ft) S = Culvert barrel slope, (ft/ft) [STAND PIPE STAGE VS. DISCHARGE] Elevation Stage Weirs Orifices Stand Pipe Culvert Total (ft) (ft) (cfs) (cfs) (cfs) (cfs) (cfs) 415.00 13.00 0.00 0.00 0.00 306.81 0.00 415.50 13.50 0.00 9.63 0.00 314.60 9.63 416.00 14.00 0.00 27.23 0.00 322.21 27.23 416.50 14.50 0.00 50.02 0.00 329.64 50.02 417.00 15.00 0.00 71.47 0.00 336.90 71.47 417.50 15.50 0.00 85.90 0.00 344.02 85.90 418.00 16.00 0.00 98.23 5.61 350.99 103.84 418.50 16.50 0.00 109.17 36.76 357.82 145.93 419.00 17.00 0.00 119.12 82.51 364.52 201.63 419.50 17.50 0.00 128.29 138.30 371.11 266.59 420.00 18.00 0.00 136.85 181.67 377.58 318.52 420.50 18.50 0.00 144.91 216.53 383.94 361.44 421.00 19.00 0.00 152.54 235.73 390.19 388.27 421.50 19.50 0.00 159.81 253.48 396.35 396.35 422.00 20.00 0.00 166.76 270.06 402.41 402.41 Dominion Development Resources, LLC Page 86 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Reservoir Report Reservoir Number: 1 Name: SWM Facility #1 [RATING CURVE LIMIT] Minimum Elevation = 402.00 (ft) Maximum Elevation = 422.00 (ft) Elevation Increment = 0.25 (ft) [STAGE STORAGE INFORMATION] Storage Method: User-Defined Storage Input Method: Area Number Elevation Area Ave Area Volume Cumulative Volume (ft) (sq ft) (sq ft) (cu ft) (cu ft) 1 415.00 0.00 0.00 0.00 0.00 2 415.10 72051.00 36025.50 3602.55 3602.55 3 416.00 77362.00 74706.50 67235.85 70838.40 4 418.00 89904.00 83633.00 167266.00 238104.40 5 420.00 105457.00 97680.50 195361.00 433465.40 6 422.00 118650.00 112053.50 224107.00 657572.40 [DISCHARGE INFORMATION] Structure Number: 1 Type: Name: SWM #1 Riser 4. [RESERVOIR STAGE STORAGE/DISCHARGE] Elevation Stage Area Storage Discharge (ft) (ft) (sq ft) (cu ft) (cfs) 415.00 13.00 0.00 0.00 0.00 415.50 13.50 74411.44 27535.47 9.63 416.00 14.00 77362.00 65478.83 27.23 416.50 14.50 80497.50 104943.71 50.02 417.00 15.00 83633.00 145976.33 71.47 417.50 15.50 86768.50 188576.71 85.90 418.00 16.00 89904.00 232744.83 103.84 418.50 16.50 93792.25 278668.90 145.93 419.00 17.00 97680.50 326537.08 201.63 419.50 17.50 101568.75 376349.40 266.59 420.00 18.00 105457.00 428105.83 318.52 420.50 18.50 108755.25 481658.90 361.44 421.00 19.00 112053.50 536861.08 388.27 421.50 19.50 115351.75 593712.40 396.35 422.00 20.00 118650.00 652212.83 402.41 Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 402.41 (cfs) Dominion Development Resources, LLC Page 87 (434)984-1599 i Luxor Subdivision Stormwater Management Pond#1 Routed Hydrograph Report Name: SWM1, 2yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 78.32 (cfs) Time to Peak (Tp) = 43.00 (min) Time of Base (Tb) = 1375.00 (min) Volume = 11.72 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 417.23 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-Fontana Pond & DA-1 & SWM2, 2yr Peak Flow (Qp) = 167.19 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1292.00 (min) Volume = 11.72 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 a Where: I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 7.78 7.78 0.00 461.41 0.09 230.75 415.01 2 2.00 15.75 23.53 461.41 1846.98 0.34 923.66 415.03 3 3.00 23.91 39.66 1846.98 4159.09 0.78 2079.93 415.06 4 4.00 32.26 56.18 4159.09 7399.58 1.38 3700.48 415.10 5 5.00 40.79 73.06 7399.58 11569.76 2.16 5785.96 415.16 6 6.00 49.50 90.30 11569.76 16670.42 3.11 8336.76 415.23 7 7.00 58.47 107.97 16670.42 22711.45 4.16 11357.81 415.28 8 8.00 67.63 126.10 22711.45 29706.37 5.34 14855.86 415.33 9 9.00 76.97 144.61 29706.37 37659.91 6.69 18833.30 415.38 10 10.00 86.48 163.46 37659.91 46573.22 8.19 23290.71 415.44 Dominion Development Resources, LLC Page 88 (434)984-1599 a Luxor Subdivision Stormwater Management Pond#1 Routed Hydrograph Report SWM1, 2yr [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 96.16 182.64 46573.22 56443.15 9.92 28226.54 415.51 12 12.00 106.55 202.71 56443.15 67273.49 12.25 33642.87 415.58 13 13.00 117.14 223.70 67273.49 79071.38 14.78 39543.08 415.66 14 14.00 127.88 245.02 79071.38 91832.71 17.51 45925.11 415.74 15 15.00 138.93 266.81 91832.71 105533.14 20.90 52777.02 415.83 16 16.00 144.20 283.12 105533.14 119795.93 24.45 59910.19 415.93 17 17.00 149.59 293.78 119795.93 134263.14 28.15 67145.65 416.02 18 18.00 155.11 304.70 134263.14 148919.20 32.21 74475.70 416.12 19 19.00 161.11 316.22 148919.20 163776.06 36.33 81906.20 416.21 20 20.00 167.19 328.30 163776.06 178847.61 40.71 89444.16 416.31 21 21.00 166.78 333.97 178847.61 193727.91 45.18 96886.55 416.40 22 22.00 164.38 331.16 193727.91 207916.07 49.44 103982.76 416.49 23 23.00 161.88 326.26 207916.07 221299.46 53.69 110676.58 416.57 24 24.00 159.48 321.35 221299.46 233891.99 57.72 116974.86 416.65 25 25.00 154.84 314.32 233891.99 245595.95 61.47 122828.71 416.72 26 26.00 150.01 304.85 245595.95 256342.42 64.23 128203.32 416.79 27 27.00 145.16 295.17 256342.42 266222.66 66.24 133144.45 416.85 28 28.00 140.30 285.47 266222.66 275288.89 68.09 137678.49 416.90 29 29.00 135.43 275.73 275288.89 283559.06 69.77 141814.42 416.95 30 30.00 130.54 265.97 283559.06 291051.03 71.30 145561.16 416.99 31 31.00 125.64 256.18 291051.03 297790.79 72.53 148931.66 417.04 32 32.00 120.72 246.36 297790.79 303803.60 73.60 151938.60 417.07 33 33.00 115.79 236.52 303803.60 309104.68 74.55 154589.61 417.10 34 34.00 110.86 226.65 309104.68 313707.69 75.37 156891.53 417.13 35 35.00 105.90 216.76 313707.69 317625.79 76.07 158850.93 417.15 36 36.00 100.93 206.83 317625.79 320871.89 76.65 160474.27 417.17 37 37.00 95.96 196.89 320871.89 323458.82 77.11 161767.97 417.19 38 38.00 92.21 188.17 323458.82 325473.23 77.47 162775.35 417.20 39 39.00 89.71 181.92 325473.23 327074.05 77.76 163575.90 417.21 40 40.00 87.19 176.89 327074.05 328342.63 77.99 164210.31 417.22 41 41.00 84.66 171.84 328342.63 329284.47 78.16 164681.31 417.22 42 42.00 82.11 166.77 329284.47 329905.05 78.27 164991.66 417.23 43 43.00 79.56 161.67 329905.05 330209.79 78.32 165144.06 417.23 44 44.00 76.99 156.54 330209.79 330204.01 78.32 165141.17 417.23 45 45.00 74.41 151.40 330204.01 329892.92 78.26 164985.59 417.23 46 46.00 71.82 146.23 329892.92 329281.63 78.15 164679.89 417.22 47 47.00 69.22 141.04 329281.63 328375.13 77.99 164226.56 417.22 48 48.00 66.60 135.82 328375.13 327178.33 77.78 163628.05 417.21 49 49.00 63.98 130.58 327178.33 325696.02 77.51 162886.77 417.20 50 50.00 61.34 125.32 325696.02 323932.92 77.20 162005.06 417.19 51 51.00 61.32 122.66 323932.92 322049.28 76.86 161063.07 417.18 52 52.00 61.28 122.60 322049.28 320201.97 76.53 160139.25 417.17 53 53.00 61.23 122.52 320201.97 318388.89 76.21 159232.55 417.16 54 54.00 61.18 122.41 318388.89 316607.97 75.89 158341.93 417.15 55 55.00 61.11 122.28 316607.97 314857.22 75.58 157466.40 417.14 56 56.00 61.03 122.13 314857.22 313134.71 75.27 156604.99 417.13 57 57.00 60.93 121.96 313134.71 311438.56 74.97 155756.76 417.12 58 58.00 60.83 121.77 311438.56 309766.83 74.67 154920.75 417.11 59 59.00 60.72 121.55 309766.83 308117.55 74.37 154095.96 417.10 60 60.00 60.59 121.30 308117.55 306488.92 74.08 153281.50 417.09 61 61.00 60.45 121.04 306488.92 304879.19 73.79 152476.49 417.08 62 62.00 60.30 120.76 304879.19 303286.67 73.51 151680.09 417.07 63 63.00 60.15 120.45 303286.67 301709.86 73.23 150891.54 417.06 64 64.00 59.98 120.13 301709.86 300147.59 72.95 150110.27 417.05 Dominion Development Resources, LLC Page 89 (434)984-1599 i Luxor Subdivision Stormwater Management Pond#1 Routed Hydrograph Report Name: SWM1, l0yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 96.00 (cfs) Time to Peak (Tp) = 42.00 (min) Time of Base (Tb) = 1397.00 (min) Volume = 16.55 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 417.83 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-Fontana Pond & DA-1 & SWM2, l0yr Peak Flow (Qp) = 229.63 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1315.00 (min) Volume = 16.55 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 1 Where: Il = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 10.90 10.90 0.00 646.39 0.12 323.25 415.01 2 2.00 22.07 32.96 646.39 2587.67 0.48 1294.08 415.04 3 3.00 33.51 55.58 2587.67 5827.71 1.09 2914.40 415.08 4 4.00 45.22 78.74 5827.71 10369.54 1.94 5185.74 415.14 5 5.00 57.19 102.41 10369.54 16215.43 3.03 8109.23 415.22 6 6.00 69.51 126.70 16215.43 23378.39 4.27 11691.33 415.28 7 7.00 82.12 151.63 23378.39 31876.06 5.71 15940.88 415.34 8 8.00 94.98 177.10 31876.06 41715.72 7.37 20861.54 415.41 9 9.00 108.09 203.07 41715.72 52900.22 9.26 26454.74 415.49 10 10.00 122.01 230.10 52900.22 65437.01 11.85 32724.43 415.57 Dominion Development Resources, LLC Page 90 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Routed Hydrograph Report SWM1, l0yr [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 136.33 258.34 65437.01 79333.49 14.83 39674.16 415.66 12 12.00 150.89 287.22 79333.49 94583.12 18.17 47300.64 415.76 13 13.00 166.18 317.07 94583.12 111174.32 22.30 55598.31 415.87 14 14.00 181.79 347.96 111174.32 129102.90 26.77 64564.84 415.99 15 15.00 197.69 379.47 129102.90 148336.58 32.05 74184.31 416.11 16 16.00 205.51 403.19 148336.58 168343.99 37.59 84190.79 416.24 17 17.00 213.49 418.99 168343.99 188603.57 43.64 94323.61 416.37 18 18.00 219.69 433.18 188603.57 208983.82 49.76 104516.79 416.49 19 19.00 225.12 444.80 208983.82 229304.63 56.25 114680.44 416.62 20 20.00 229.63 454.74 229304.63 249445.22 62.70 124753.96 416.74 21 21.00 222.83 452.46 249445.22 268819.97 66.77 134443.37 416.86 22 22.00 216.06 438.89 268819.97 286915.91 70.46 143493.18 416.97 23 23.00 209.31 425.37 286915.91 303791.51 73.60 151932.55 417.07 24 24.00 202.58 411.89 303791.51 319501.89 76.41 159789.15 417.16 25 25.00 195.88 398.46 319501.89 334081.54 79.01 167080.28 417.25 26 26.00 189.16 385.04 334081.54 347570.62 81.17 173825.90 417.33 27 27.00 182.44 371.60 347570.62 360004.47 83.16 180043.82 417.40 28 28.00 175.68 358.12 360004.47 371400.63 84.99 185742.81 417.47 29 29.00 168.91 344.60 371400.63 381780.51 86.58 190933.54 417.53 30 30.00 162.12 331.03 381780.51 391169.22 87.95 195628.59 417.58 31 31.00 155.31 317.43 391169.22 399586.43 89.17 199837.80 417.63 32 32.00 148.48 303.79 399586.43 407046.63 90.26 203568.45 417.67 33 33.00 141.63 290.11 407046.63 413564.20 91.21 206827.70 417.71 ' 34 34.00 134.76 276.39 413564.20 419153.16 92.02 209622.59 417.74 35 35.00 127.88 262.64 419153.16 423806.86 93.04 211949.95 417.77 36 36.00 120.97 248.85 423806.86 427514.43 94.00 213804.22 417.79 37 37.00 114.05 235.02 427514.43 430291.53 94.72 215193.13 417.80 38 38.00 108.85 222.90 430291.53 432267.26 95.24 216181.25 417.81 39 39.00 105.36 214.21 432267.26 433669.29 95.60 216882.44 417.82 40 40.00 101.86 207.22 433669.29 434615.66 95.85 217355.75 417.83 41 41.00 98.34 200.21 434615.66 435118.40 95.98 217607.19 417.83 42 42.00 94.81 193.15 435118.40 435189.28 96.00 217642.64 417.83 43 43.00 91.26 186.07 435189.28 434839.59 95.90 217467.75 417.83 44 44.00 87.69 178.95 434839.59 434080.25 95.71 217087.98 417.82 45 45.00 84.11 171.81 434080.25 432922.00 95.41 216508.70 417.82 46 46.00 80.52 164.63 432922.00 431375.31 95.00 215735.16 417.81 47 47.00 76.90 157.42 431375.31 429450.34 94.50 214772.42 417.80 48 48.00 73.28 150.18 429450.34 427156.93 93.91 213625.42 417.79 49 49.00 69.64 142.91 427156.93 424504.66 93.22 212298.94 417.77 50 50.00 65.98 135.62 424504.66 421502.78 92.44 210797.61 417.75 51 51.00 66.01 131.99 421502.78 418361.63 91.91 209226.77 417.74 52 52.00 66.02 132.02 418361.63 415281.55 91.46 207686.51 417.72 53 53.00 66.02 132.03 415281.55 412255.36 91.02 206173.19 417.70 54 54.00 66.00 132.01 412255.36 409280.43 90.59 204685.51 417.68 55 55.00 65.97 131.97 409280.43 406354.22 90.16 203222.19 417.67 56 56.00 65.92 131.89 406354.22 403474.19 89.74 201781.97 417.65 57 57.00 65.86 131.79 403474.19 400637.83 89.33 200363.58 417.63 58 58.00 65.79 131.66 400637.83 397842.71 88.92 198965.82 417.62 59 59.00 65.70 131.49 397842.71 395086.46 88.52 197587.49 417.60 60 60.00 65.60 131.31 395086.46 392366.73 88.12 196227.43 417.59 61 61.00 65.49 131.09 392366.73 389681.26 87.73 194884.49 417.57 62 62.00 65.36 130.85 389681.26 387027.79 87.35 193557.57 417.56 63 63.00 65.22 130.58 387027.79 384404.26 86.96 192245.61 417.54 64 64.00 65.07 130.29 384404.26 381809.16 86.59 190947.87 417.53 Dominion Development Resources, LLC Page 91 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Routed Hydrograph Report Name: SWM1, 100yr Type: Reservoir: Modified Puls [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 148.21 (cfs) Time to Peak (Tp) = 36.00 (min) Time of Base (Tb) = 1413.00 (min) Volume = 23.91 (ac-ft) Time Step = 1.00 (min) Peak Elevation = 418.52 (ft) Detention Time = NA [RESERVOIR STRUCTURE INFORMATION] Name = SWM Facility #1 Storage Type = User-Defined Area Maximum Storage = 652212.83 (cu ft) Maximum Discharge = 423.00 (cfs) [INFLOW HYDROGRAPH INFORMATION] Name = DA-Fontana Pond & DA-1 & SWM2, 100yr Peak Flow (Qp) = 307.10 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 1330.00 (min) Volume = 23.91 (ac-ft) Flow Multiplier = 1.00 [EQUATION] (I1+I2) + (2(S1)/dt)-01 = (2(S2)/dt)+02 Where: I1 = Previous inflow I2 = Current inflow S1 = Previous storage S2 = Current storage dt = Time increment 01 = Previous outflow 02 = Current outflow A = (I1 + I2) B = (2 (S1) / dt) - 01 C = (2 (S2) / dt) + 02 [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 1 1.00 15.67 15.67 0.00 929.83 0.17 465.00 415.01 2 2.00 31.75 47.42 929.83 3722.61 0.69 1861.65 415.05 3 3.00 48.22 79.97 3722.61 8384.28 1.57 4192.92 415.11 4 4.00 65.07 113.29 8384.28 14919.60 2.79 7461.19 415.20 5 5.00 82.41 147.48 14919.60 23344.00 4.27 11674.13 415.28 6 6.00 100.18 182.59 23344.00 33680.79 6.01 16843.40 415.35 7 7.00 118.33 218.51 33680.79 45943.17 8.09 22975.63 415.44 8 8.00 137.20 255.53 45943.17 60143.94 10.72 30077.33 415.53 9 9.00 156.98 294.17 60143.94 76297.06 14.18 38155.62 415.64 10 10.00 177.14 334.12 76297.06 94401.58 18.13 47209.85 415.76 Dominion Development Resources,LLC Page 92 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Routed Hydrograph Report SWM1, 100yr [Computation of Reservoir Outflow Table of Modified Puls Method] Intv Time Inflow A B C Outflow Storage Elev (min) (cfs) (cfs) (cfs) (cfs) (cfs) (cu ft) (ft) 11 11.00 198.41 375.55 94401.58 114454.66 23.12 57238.89 415.89 12 12.00 220.05 418.46 114454.66 136443.79 28.75 68236.27 416.04 13 13.00 242.56 462.61 136443.79 160345.64 35.38 80190.51 416.19 14 14.00 265.48 508.04 160345.64 186123.93 42.90 93083.41 416.35 15 15.00 285.55 551.02 186123.93 213531.22 51.20 106791.21 416.52 16 16.00 292.90 578.44 213531.22 241546.38 60.17 120803.28 416.70 17 17.00 296.39 589.29 241546.38 269274.93 66.86 134670.90 416.86 18 18.00 299.93 596.33 269274.93 296697.42 72.33 148384.87 417.03 19 19.00 303.50 603.44 296697.42 323926.97 77.20 162002.08 417.19 20 20.00 307.10 610.61 323926.97 351023.54 81.73 175552.63 417.35 21 21.00 297.39 604.50 351023.54 377230.55 85.92 188658.23 417.50 22 22.00 287.71 585.11 377230.55 401808.25 89.50 200948.88 417.64 23 23.00 278.05 565.77 401808.25 424783.03 93.29 212438.16 417.77 24 24.00 268.42 546.48 424783.03 446039.86 98.81 223069.34 417.89 25 25.00 258.82 527.24 446039.86 465507.14 103.89 232805.51 418.00 26 26.00 249.21 508.03 465507.14 483074.98 111.22 241593.10 418.10 27 27.00 239.57 488.78 483074.98 498658.82 117.72 249388.27 418.18 28 28.00 229.90 469.47 498658.82 512344.40 123.56 256233.98 418.26 29 29.00 220.20 450.10 512344.40 524163.61 129.46 262146.53 418.32 30 30.00 210.47 430.67 524163.61 534164.57 134.45 267149.51 418.38 31 31.00 200.71 411.18 534164.57 542449.45 138.58 271294.02 418.42 32 32.00 190.92 391.62 542449.45 549114.56 141.90 274628.23 418.46 33 33.00 181.10 372.02 549114.56 554250.59 144.47 277197.53 418.48 34 34.00 171.25 352.35 554250.59 557940.29 146.35 279043.32 418.50 35 35.00 161.37 332.62 557940.29 560256.26 147.65 280201.95 418.52 36 36.00 151.47 312.84 560256.26 561274.33 148.21 280711.27 418.52 37 37.00 141.53 293.00 561274.33 561075.28 148.10 280611.69 418.52 38 38.00 134.06 275.59 561075.28 559879.19 147.43 280013.31 418.51 39 39.00 129.05 263.11 559879.19 558036.20 146.41 279091.30 418.50 40 40.00 124.01 253.06 558036.20 555724.41 145.20 277934.81 418.49 41 41.00 118.95 242.96 555724.41 552961.87 143.82 276552.85 418.48 42 42.00 113.87 232.82 552961.87 549769.23 142.23 274955.73 418.46 43 43.00 108.77 222.63 549769.23 546169.12 140.44 273154.78 418.44 44 44.00 103.64 212.41 546169.12 542182.74 138.45 271160.59 418.42 45 45.00 98.50 202.14 542182.74 537830.21 136.27 268983.24 418.40 46 46.00 93.34 191.84 537830.21 533130.59 133.93 266632.26 418.37 47 47.00 88.16 181.50 533130.59 528101.71 131.42 264116.57 418.34 48 48.00 82.96 171.11 528101.71 522760.43 128.76 261444.59 418.31 49 49.00 77.74 160.69 522760.43 517122.79 125.94 258624.37 418.28 50 50.00 72.50 150.24 517122.79 511203.93 122.99 255663.46 418.25 51 51.00 72.58 145.08 511203.93 505302.30 120.50 252711.40 418.22 52 52.00 72.65 145.23 505302.30 499699.34 118.16 249908.75 418.19 53 53.00 72.70 145.34 499699.34 494376.47 115.94 247246.20 418.16 54 54.00 72.72 145.42 494376.47 489317.98 113.83 244715.91 418.13 55 55.00 72.74 145.46 489317.98 484508.99 111.82 242310.40 418.11 56 56.00 72.73 145.47 484508.99 479935.31 109.91 240022.61 418.08 57 57.00 72.71 145.45 479935.31 475583.48 108.10 237845.79 418.06 58 58.00 72.67 145.39 475583.48 471440.70 106.37 235773.53 418.03 59 59.00 72.62 145.29 471440.70 467494.79 104.72 233799.76 418.01 60 60.00 72.55 145.17 467494.79 463718.51 103.41 231910.96 417.99 61 61.00 72.46 145.01 463718.51 460067.81 102.46 230085.13 417.97 62 62.00 72.35 144.81 460067.81 456517.53 101.54 228309.53 417.95 63 63.00 72.23 144.58 456517.53 453062.84 100.64 226581.74 417.93 Dominion Development Resources, LLC Page 93 (434)984-1599 e Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report Name: DA-1, Uncontained 2yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 54.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 1.86 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 1.86 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Impervious Areas 0.70 0 0.90 Unimproved Areas 18.00 0 0.30 Avemore & Unimproved Areas 22.20 0 0.30 Town & Country (Future) 4.00 0 0.70 r Fontana 6.00 0 0.50 Overall Approximation 50.90 NA 0.36 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 0.97 (in) Return Period = 2 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources,LLC Page 94 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report DA-1, Uncontained 2yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.05 0.00 2.71 2 2.00 0.05 0.10 2.71 5.41 3 3.00 0.05 0.15 2.71 8.12 4 4.00 0.05 0.19 2.71 10.82 5 5.00 0.05 0.24 2.71 13.53 6 6.00 0.05 0.29 2.71 16.23 7 7.00 0.05 0.34 2.71 18.94 8 8.00 0.05 0.39 2.71 21.65 9 9.00 0.05 0.44 2.71 24.35 10 10.00 0.05 0.48 2.71 27.06 11 11.00 0.05 0.53 2.71 29.76 12 12.00 0.05 0.58 2.71 32.47 13 13.00 0.05 0.63 2.71 35.17 14 14.00 0.05 0.68 2.71 37.88 15 15.00 0.05 0.73 2.71 40.59 16 16.00 0.05 0.77 2.71 43.29 17 17.00 0.05 0.82 2.71 46.00 18 18.00 0.05 0.87 2.71 48.70 19 19.00 0.05 0.92 2.71 51.41 20 20.00 0.05 0.97 2.71 54.12 21 21.00 0.00 0.97 -1.80 52.31 22 22.00 0.00 0.97 -1.80 50.51 23 23.00 0.00 0.97 -1.80 48.70 24 24.00 0.00 0.97 -1.80 46.90 25 25.00 0.00 0.97 -1.80 45.10 26 26.00 0.00 0.97 -1.80 43.29 27 27.00 0.00 0.97 -1.80 41.49 28 28.00 0.00 0.97 -1.80 39.68 29 29.00 0.00 0.97 -1.80 37.88 30 30.00 0.00 0.97 -1.80 36.08 31 31.00 0.00 0.97 -1.80 34.27 32 32.00 0.00 0.97 -1.80 32.47 33 33.00 0.00 0.97 -1.80 30.67 34 34.00 0.00 0.97 -1.80 28.86 35 35.00 0.00 0.97 -1.80 27.06 36 36.00 0.00 0.97 -1.80 25.25 37 37.00 0.00 0.97 -1.80 23.45 38 38.00 0.00 0.97 -1.80 21.65 39 39.00 0.00 0.97 -1.80 19.84 40 40.00 0.00 0.97 -1.80 18.04 41 41.00 0.00 0.97 -1.80 16.23 42 42.00 0.00 0.97 -1.80 14.43 43 43.00 0.00 0.97 -1.80 12.63 44 44.00 0.00 0.97 -1.80 10.82 45 45.00 0.00 0.97 -1.80 9.02 46 46.00 0.00 0.97 -1.80 7.22 47 47.00 0.00 0.97 -1.80 5.41 48 48.00 0.00 0.97 -1.80 3.61 49 49.00 0.00 0.97 -1.80 1.80 50 50.00 0.00 0.97 -1.80 0.00 F Dominion Development Resources, LLC Page 95 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report Name: DA-1, Uncontained l0yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 76.29 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 2.63 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 2.63 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CV Runoff Coef Impervious Areas 0.70 0 0.90 Unimproved Areas 18.00 0 0.30 Avemore & Unimproved Areas 22.20 0 0.30 Town & Country (Future) 4.00 0 0.70 Fontana 6.00 0 0.50 Overall Approximation 50.90 NA 0.36 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.36 (in) Return Period = User Defined (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 96 (434)984-1599 a Luxor Subdivision Stormwater Management Pond #1 Uncontained Hydrograph Report DA-1, Uncontained l0yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.07 0.00 3.81 2 2.00 0.07 0.14 3.81 7.63 3 3.00 0.07 0.20 3.81 11.44 4 4.00 0.07 0.27 3.81 15.26 5 5.00 0.07 0.34 3.81 19.07 6 6.00 0.07 0.41 3.81 22.89 7 7.00 0.07 0.48 3.81 26.70 8 8.00 0.07 0.55 3.81 30.52 9 9.00 0.07 0.61 3.81 34.33 10 10.00 0.07 0.68 3.81 38.15 11 11.00 0.07 0.75 3.81 41.96 12 12.00 0.07 0.82 3.81 45.77 13 13.00 0.07 0.89 3.81 49.59 14 14.00 0.07 0.95 3.81 53.40 15 15.00 0.07 1.02 3.81 57.22 16 16.00 0.07 1.09 3.81 61.03 17 17.00 0.07 1.16 3.81 64.85 18 18.00 0.07 1.23 3.81 68.66 19 19.00 0.07 1.30 3.81 72.48 20 20.00 0.07 1.36 3.81 76.29 21 21.00 0.00 1.36 -2.54 73.75 22 22.00 0.00 1.36 -2.54 71.20 g 23 23.00 0.00 1.36 -2.54 68.66 24 24.00 0.00 1.36 -2.54 66.12 25 25.00 0.00 1.36 -2.54 63.58 26 26.00 0.00 1.36 -2.54 61.03 27 27.00 0.00 1.36 -2.54 58.49 28 28.00 0.00 1.36 -2.54 55.95 29 29.00 0.00 1.36 -2.54 53.40 30 30.00 0.00 1.36 -2.54 50.86 31 31.00 0.00 1.36 -2.54 48.32 32 32.00 0.00 1.36 -2.54 45.77 33 33.00 0.00 1.36 -2.54 43.23 34 34.00 0.00 1.36 -2.54 40.69 35 35.00 0.00 1.36 -2.54 38.15 36 36.00 0.00 1.36 -2.54 35.60 37 37.00 0.00 1.36 -2.54 33.06 38 38.00 0.00 1.36 -2.54 30.52 39 39.00 0.00 1.36 -2.54 27.97 40 40.00 0.00 1.36 -2.54 25.43 41 41.00 0.00 1.36 -2.54 22.89 42 42.00 0.00 1.36 -2.54 20.34 43 43.00 0.00 1.36 -2.54 17.80 44 44.00 0.00 1.36 -2.54 15.26 45 45.00 0.00 1.36 -2.54 12.72 46 46.00 0.00 1.36 -2.54 10.17 47 47.00 0.00 1.36 -2.54 7.63 48 48.00 0.00 1.36 -2.54 5.09 49 49.00 0.00 1.36 -2.54 2.54 50 50.00 0.00 1.36 -2.54 0.00 P Dominion Development Resources, LLC Page 97 (434)984-1599 Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report Name: DA-1, Uncontained 100yr Type: Modified Rational [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 110.14 (cfs) Time to Peak (Tp) = 20.00 (min) Time of Base (Tb) = 50.00 (min) Volume = 3.79 (ac-ft) Time Step = 1.00 (min) Flow Multiplier = 1.00 [RATIONAL HYDROGRAPH INFORMATION] Flow Multiplier = 1.00 Receding Limb Factor = 1.50 [APPROXIMATE STORAGE] Maximum Outflow = 0.00 (cfs) Maximum Storage = 3.79 (cu ft) [BASIN INFORMATION] [WEIGHTED WATERSHED AREA] Description Area CN Runoff Coef Impervious Areas 0.70 0 0.90 Unimproved Areas 18.00 0 0.30 Avemore & Unimproved Areas 22.20 0 0.30 Town & Country (Future) 4.00 0 0.70 Fontana 6.00 0 0.50 Overall Approximation 50.90 NA 0.36 [TIME CONCENTRATION -- User Defined] Time of Concentration (Tc) = 20.00 (min) [RAINFALL DESCRIPTION] Distribution Type = Synthetic Total Precipitation = 1.97 (in) Return Period = 100 (yr) Storm Duration = 0.33 (hr) Dominion Development Resources, LLC Page 98 (434)984-1599 Luxor Subdivision Stormwater Management Pond #1 Uncontained Hydrograph Report DA-1, Uncontained 100yr [Hydrograph Flow Values: Time vs. Flow] Time Time Incremental Cumulative Incremental Design Interval Rainfall Rainfall Outflow Outflow (min) (in) (in) (cfs) (cfs) 1 1.00 0.00 0.10 0.00 5.51 2 2.00 0.10 0.20 5.51 11.01 3 3.00 0.10 0.30 5.51 16.52 4 4.00 0.10 0.39 5.51 22.03 5 5.00 0.10 0.49 5.51 27.53 6 6.00 0.10 0.59 5.51 33.04 7 7.00 0.10 0.69 5.51 38.55 8 8.00 0.10 0.79 5.51 44.05 9 9.00 0.10 0.89 5.51 49.56 10 10.00 0.10 0.98 5.51 55.07 11 11.00 0.10 1.08 5.51 60.58 12 12.00 0.10 1.18 5.51 66.08 13 13.00 0.10 1.28 5.51 71.59 14 14.00 0.10 1.38 5.51 77.10 15 15.00 0.10 1.48 5.51 82.60 16 16.00 0.10 1.58 '5.51 88.11 17 17.00 0.10 1.67 5.51 93.62 18 18.00 0.10 1.77 5.51 99.12 19 19.00 0.10 1.87 5.51 104.63 20 20.00 0.10 1.97 5.51 110.14 21 21.00 0.00 1.97 -3.67 106.47 22 22.00 0.00 1.97 -3.67 102.79 . 23 23.00 0.00 1.97 -3.67 99.12 24 24.00 0.00 1.97 -3.67 95.45 25 25.00 0.00 1.97 -3.67 91.78 26 26.00 0.00 1.97 -3.67 88.11 27 27.00 0.00 1.97 -3.67 84.44 28 28.00 0.00 1.97 -3.67 80.77 29 29.00 0.00 1.97 -3.67 77.10 30 30.00 0.00 1.97 -3.67 73.42 31 31.00 0.00 1.97 -3.67 69.75 32 32.00 0.00 1.97 -3.67 66.08 33 33.00 0.00 1.97 -3.67 62.41 34 34.00 0.00 1.97 -3.67 58.74 35 35.00 0.00 1.97 -3.67 55.07 36 36.00 0.00 1.97 -3.67 51.40 37 37.00 0.00 1.97 -3.67 47.73 38 38.00 0.00 1.97 -3.67 44.05 39 39.00 0.00 1.97 -3.67 40.38 40 40.00 0.00 1.97 -3.67 36.71 41 41.00 0.00 1.97 -3.67 33.04 42 42.00 0.00 1.97 -3.67 29.37 43 43.00 0.00 1.97 -3.67 25.70 44 44.00 0.00 1.97 -3.67 22.03 45 45.00 0.00 1.97 -3.67 18.36 46 46.00 0.00 1.97 -3.67 14.68 47 47.00 0.00 1.97 -3.67 11.01 48 48.00 0.00 1.97 -3.67 7.34 49 49.00 0.00 1.97 -3.67 3.67 50 50.00 0.00 1.97 -3.67 0.00 . Dominion Development Resources, LLC Page 99 (434)984-1599 • a Luxor Subdivision Stormwater Management Pond#1 Uncontained Hydrograph Report Name: SWM1 & DA-1 Uncontained, 2yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 107.77 (cfs) Time to Peak (Tp) = 28.00 (min) Time of Base (Tb) = 1375.00 (min) Volume = 13.59 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: SWM1, 2yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 78.32 (cfs) Time to Peak (Tp) = 43.00 (min) Time Step = 1.00 (min) Name: DA-1, Uncontained 2yr Type: Modified Rational Peak Flow (Qp) = 54.12 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 1 1.00 2.79 2 2.00 5.76 3 3.00 8.89 4 4.00 12.20 5 5.00 15.69 6 6.00 19.35 7 7.00 23.10 8 8.00 26.99 9 9.00 31.04 10 10.00 35.25 11 11.00 39.69 12 12.00 44.71 13 13.00 49.95 14 14.00 55.39 15 15.00 61.49 16 16.00 67.74 17 17.00 74.15 18 18.00 80.91 19 19.00 87.74 20 20.00 94.83 21 21.00 97.49 22 22.00 99.95 23 23.00 102.39 24 24.00 104.62 25 25.00 106.57 26 26.00 107.52 27 27.00 107.73 28 28.00 107.77 29 29.00 107.65 30 30.00 107.38 31 31.00 106.80 K Dominion Development Resources, LLC Page 100 (434)984-1599 r Luxor Subdivision Stormwater Management Pond#1 r Combined Hydrograph Report SWM1 & DA-1 Uncontained, 2yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 32 32.00 106.07 33 33.00 105.21 34 34.00 104.23 35 35.00 103.13 36 36.00 101.91 37 37.00 100.56 38 38.00 99.12 39 39.00 97.60 40 40.00 96.03 41 41.00 94.39 42 42.00 92.70 43 43.00 90.95 44 44.00 89.14 45 45.00 87.28 46 46.00 85.37 47 47.00 83.40 48 48.00 81.39 49 49.00 79.32 50 50.00 77.20 51 51.00 76.86 52 52.00 76.53 53 53.00 76.21 54 54.00 75.89 ft 55 55.00 75.58 56 56.00 75.27 57 57.00 74.97 58 58.00 74.67 59 59.00 74.37 60 60.00 74.08 61 61.00 73.79 62 62.00 73.51 63 63.00 73.23 64 64.00 72.95 65 65.00 72.67 66 66.00 72.40 67 67.00 72.12 68 68.00 71.85 69 69.00 71.59 70 70.00 71.30 71 71.00 71.00 72 72.00 70.71 73 73.00 70.41 74 74.00 70.13 75 75.00 69.84 76 76.00 69.56 77 77.00 69.27 78 78.00 68.98 79 79.00 68.66 80 80.00 68.31 81 81.00 67.94 82 82.00 67.53 83 83.00 67.09 84 84.00 66.60 85 85.00 66.06 i Dominion Development Resources,LLC Page 101 (434)984-1599 i Luxor Subdivision Stormwater Management Pond#1 Combined Hydrograph Report Name: SWM1 & DA-1 Uncontained, l0yr Type: Combined [HYDROGRAPH INFORMATION] Peak Flow (Qp) = 142.59 (cfs) Time to Peak (Tp) = 25.00 (min) Time of Base (Tb) = 1397.00 (min) Volume = 19.17 (ac-ft) Time Step = 1.00 (min) [COMBINED HYDROGRAPH RECORDS] Name: SWM1, l0yr Type: Reservoir: Modified Puls Peak Flow (Qp) = 96.00 (cfs) Time to Peak (Tp) = 42.00 (min) Time Step = 1.00 (min) Name: DA-1, Uncontained 10yr Type: Modified Rational Peak Flow (Qp) = 76.29 (cfs) Time to Peak (Tp) = 20.00 (min) Time Step = 1.00 (min) [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) r 1 1.00 3.94 2 2.00 8.11 3 3.00 12.53 4 4.00 17.19 5 5.00 22.10 6 6.00 27.16 7 7.00 32.41 8 8.00 37.89 9 9.00 43.59 10 10.00 50.00 11 11.00 56.79 12 12.00 63.95 13 13.00 71.89 14 14.00 80.17 15 15.00 89.27 16 16.00 98.63 17 17.00 108.49 18 18.00 118.42 19 19.00 128.73 20 20.00 138.99 21 21.00 140.52 22 22.00 141.66 23 23.00 142.26 24 24.00 142.53 25 25.00 142.59 26 26.00 142.21 27 27.00 141.65 28 28.00 140.93 29 29.00 139.99 30 30.00 138.81 Dominion Development Resources, LLC Page 102 (434)984-1599 Luxor Subdivision ps Stormwater Management Pond #1 Combined Hydrograph Report SWM1 & DA-1 Uncontained, l0yr [Combined Hydrograph Flow Values] Interval Time Outflow (min) (cfs) 31 31.00 137.49 32 32.00 136.03 33 33.00 134.44 34 34.00 132.71 35 35.00 131.18 36 36.00 129.60 37 37.00 127.78 38 38.00 125.75 39 39.00 123.57 40 40.00 121.28 41 41.00 118.86 42 42.00 116.34 43 43.00 113.71 44 44.00 110.97 45 45.00 108.12 46 46.00 105.18 47 47.00 102.13 48 48.00 99.00 49 49.00 95.76 50 50.00 92.44 51 51.00 91.91 52 52.00 91.46 53 53.00 91.02 a 54 54.00 90.59 55 55.00 90.16 56 56.00 89.74 57 57.00 89.33 58 58.00 88.92 59 59.00 88.52 60 60.00 88.12 61 61.00 87.73 62 62.00 87.35 63 63.00 86.96 64 64.00 86.59 65 65.00 86.21 66 66.00 85.84 67 67.00 85.44 68 68.00 85.04 69 69.00 84.65 70 70.00 84.26 71 71.00 83.87 72 72.00 83.50 73 73.00 83.12 74 74.00 82.75 75 75.00 82.38 76 76.00 82.02 77 77.00 81.66 78 78.00 81.31 79 79.00 80.96 80 80.00 80.61 'Nom. 81 81.00 80.27 82 82.00 79.93 83 83.00 79.59 84 84.00 79.26 ek Dominion Development Resources, LLC Page 103 (434)984-1599 0