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HomeMy WebLinkAboutWPO202100034 Calculations 2021-12-17VICTORIAN HEIGHTS VSMP STORMWATER MANAGEMENT CALCULATIONS PACKET Date of Calculations December 16, 2021 PREPARED BY: COLLINS ENGI°-°''mRING 200 GARRETT STREET, SUITE K CHARLOTTESVILLE, VA 22902 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com SCS TR-55 Calculations Si " . . !Database) Soils Table (Source: NRCS Web Soil Survey Online Database) Note: The soils' properties witin this development are predominantly composed of hydrologic group type B soils. Albemarle County, Virginia (VA003) Albemarle County, Virginia (VA003) Map Unit Map Unit Name Percent of AOI Symbol 27B Elioak loam, 2 to 7 6.8% percent slopes 27C Elioak loam, 7 to 37.2% 15 percent slopes 39D Hazel loam, 15 to 8.9% 25 percent slopes 65B Fairview sandy 47.2% loam, 2 to 7 percent slopes Totals for Area of 100.00yo Interest Precipitation Data (Source: NOAA's National Weather Service, Hydrometerorological Design Studies Center, Atlas 14 Point Precipitation Frequency Estimates) POINT PRECIPITATION FREQUENCY (PF) ESTIMATES WITH 90% CONFIDENCE INTERVALS AND SUPPLEMENTARY INFORMATION NOAA Atlas 14, VOIUtile 2, Version 3 PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)t Average recurrence interval (years) t 2 5 70 25 50 700 200 500 7000 24hr (2.70-3.37) (3.264.08) (4.15-5.21) (/.89b.1/) (5.97-7.52) (6.87-8.70) (7.85-10.0) (8.89-11.4) (10.a13.6) (11.6-15.4) 0-3. 3.63 4.64 5.48 6.-T 7.81 8.-1 10.3 722 .6-1 Map v 0 Tertam a or E 3 0 o a) Select location Move crosshair or double click b) Clkk on stedon icon ❑ Shaw stations on map Location information: South h h„ Name: Charlottesville. Virginia, USA' oe a Latitude: 38.0975° RSoutFork River �'a e Longitude:-78,46850 Reservolr a4�s y Elevation: 500.6 it I 90 O� Ce MFd lip ° u e x P^ ya W o.6e g n r- + 3 R e 200 v g0 4 I--� A Source,-ESRI Maps aWtt s °of "Source: USGS POINT PRECIPITATION FREQUENCY (PF) ESTIMATES WITH 90% CONFIDENCE INTERVALS AND SUPPLEMENTARY INFORMATION NOAA Ada. 14, Volume 2, Version 3 Pre -Development Site Inflow Hydrographs The following inflow hydrographs reflect the pre -development inflow from the site. Worksheet 5b (Modified for Clarity): Basic watershed Data 1-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA A 0.10 0.10 0.41 0.0014 (Pre-Dev.) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.10 12.0 0.42 12.1 1.15 12.2 0.64 12.3 0.30 12.4 0.25 12.5 0.22 12.6 0.19 12.7 0.16 12.8 0.15 13.0 0.13 13.2 0.12 13.4 0.11 13.6 0.10 13.8 0.09 14.0 0.09 14.3 0.08 14.6 0.08 15.0 0.07 15.5 0.06 16.0 0.06 16.5 0.05 17.0 0.05 17.5 0.05 18.0 0.05 19.0 0.04 20.0 0.04 22.0 0.03 26.0 0.00 6 5 4 3 2 K SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) 0 5 10 15 20 25 30 Worksheet 5b (Modified for Clarity): Basic watershed Data 2-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am•Q (mil -in) DA A 0.10 0.10 0.34 0.0024 (Pre-Dev.) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.28 12.0 1.09 12.1 2.23 12.2 1.19 12.3 0.52 12.4 0.42 12.5 0.37 12.6 0.31 12.7 0.27 12.8 0.24 13.0 0.22 13.2 0.19 13.4 0.18 13.6 0.16 13.8 0.15 14.0 0.14 14.3 0.13 14.6 0.12 15.0 0.11 15.5 0.10 16.0 0.09 16.5 0.08 17.0 0.08 17.5 0.08 18.0 0.07 19.0 0.06 20.0 0.06 22.0 0.05 26.0 0.00 6 5 4 3 2 1 a SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) Worksheet 5b (Modified for Clarity): Basic watershed Data 10-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am;Q (mi2-in) DA A 0.10 0.10 0.22 0.0063 (Pre-Dev.) Hydrograph Time(hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.06 11.3 0.09 11.6 0.13 11.9 1.42 12.0 3.77 12.1 6.11 12.2 3.55 12.3 1.37 12.4 1.02 12.5 0.87 12.6 0.74 12.7 0.62 12.8 0.56 13.0 0.49 13.2 0.43 13.4 0.39 13.6 0.35 13.8 0.32 14.0 0.30 14.3 0.27 14.6 0.25 15.0 0.23 15.5 0.21 16.0 0.19 16.5 0.17 17.0 0.16 17.5 0.15 18.0 0.15 19.0 0.13 20.0 0.11 22.0 0.10 26.0 0.00 6 5 4 3 2 1 a SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A) Worksheet 5b (Modified for Clarity): Basic watershed Data 1-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am;Q (mi2-in) DA B 0.10 0.10 0.44 0.0016 (Pre-Dev.) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.07 12.0 0.35 12.1 1.22 12.2 0.66 12.3 0.32 12.4 0.27 12.5 0.24 12.6 0.21 12.7 0.18 12.8 0.16 13.0 0.15 13.2 0.13 13.4 0.12 13.6 0.11 13.8 0.11 14.0 0.10 14.3 0.09 14.6 0.09 15.0 0.08 15.5 0.07 16.0 0.07 16.5 0.06 17.0 0.06 17.5 0.06 18.0 0.05 19.0 0.05 20.0 0.04 22.0 0.04 26.0 0.00 6 5 4 3 2 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA B) Worksheet 5b (Modified for Clarity): Basic watershed Data 2-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am•Q (mil -in) DA B 0.10 0.10 0.36 0.0028 (Pre-Dev.) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.32 12.0 1.22 12.1 2.42 12.2 1.34 12.3 0.58 12.4 0.47 12.5 0.41 12.6 0.35 12.7 0.30 12.8 0.27 13.0 0.25 13.2 0.22 13.4 0.20 13.6 0.18 13.8 0.17 14.0 0.16 14.3 0.14 14.6 0.14 15.0 0.13 15.5 0.11 16.0 0.10 16.5 0.09 17.0 0.09 17.5 0.09 18.0 0.08 19.0 0.07 20.0 0.06 22.0 0.06 26.0 0.00 6 5 4 3 2 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA B) Worksheet 5b (Modified for Clarity): Basic watershed Data 10-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA B 0.10 0.10 0.24 0.0074 (Pre-Dev.) Hydrograph Time(hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.05 11.3 0.08 11.6 0.12 11.9 1.53 12.0 4.35 12.1 7.10 12.2 4.07 12.3 1.60 12.4 1.21 12.5 1.04 12.6 0.88 12.7 0.74 12.8 0.67 13.0 0.59 13.2 0.52 13.4 0.47 13.6 0.43 13.8 0.39 14.0 0.36 14.3 0.32 14.6 0.31 15.0 0.28 15.5 0.25 16.0 0.23 16.5 0.21 17.0 0.20 17.5 0.19 18.0 0.18 19.0 0.16 20.0 0.13 22.0 0.12 26.0 0.00 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA B) 0 5 10 15 20 25 30 Worksheet 5b (Modified for Clarity): Basic watershed Data 1-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA D 0.21 0.21 0.32 0.0011 (Existing Offsite-Outside LOD) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.04 12.0 0.17 12.1 0.54 12.2 0.74 12.3 0.55 12.4 0.33 12.5 0.23 12.6 0.19 12.7 0.16 12.8 0.13 13.0 0.11 13.2 0.10 13.4 0.09 13.6 0.09 13.8 0.08 14.0 0.07 14.3 0.06 14.6 0.06 15.0 0.06 15.5 0.05 16.0 0.05 16.5 0.04 17.0 0.04 17.5 0.04 18.0 0.04 19.0 0.03 20.0 0.03 22.0 0.03 26.0 0.00 0 5 4 3 2 1 0 SCS TR-55 Existing Unit Hydrograph (DA D) 0 5 10 15 20 25 30 Worksheet 5b (Modified for Clarity): Basic watershed Data 2-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi'-in) DA D 0.21 0.21 0.27 0.0018 (Existing Offsite-Outside LOD) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.01 11.3 0.01 11.6 0.01 11.9 0.11 12.0 0.36 12.1 0.97 12.2 1.25 12.3 0.90 12.4 0.52 12.5 0.36 12.6 0.29 12.7 0.23 12.8 0.20 13.0 0.16 13.2 0.14 13.4 0.13 13.6 0.12 13.8 0.11 14.0 0.10 14.3 0.08 14.6 0.08 15.0 0.07 15.5 0.07 16.0 0.06 16.5 0.05 17.0 0.05 17.5 0.05 18.0 0.05 19.0 0.04 20.0 0.04 22.0 0.03 26.0 0.00 6 SCS TR-55 Existing Unit Hydrograph (DA D) Worksheet 5b (Modified for Clarity): Basic watershed Data 10-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA D 0.21 0.21 0.18 0.0041 (Existing Offsite-Outside LOD) Hydrograph Time (hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.06 11.3 0.08 11.6 0.11 11.9 0.55 12.0 1.23 12.1 2.61 12.2 3.07 12.3 2.07 12.4 1.15 12.5 0.78 12.6 0.60 12.7 0.48 12.8 0.41 13.0 0.33 13.2 0.29 13.4 0.26 13.6 0.23 13.8 0.21 14.0 0.19 14.3 0.17 14.6 0.16 15.0 0.15 15.5 0.13 16.0 0.12 16.5 0.10 17.0 0.10 17.5 0.09 18.0 0.09 19.0 0.08 20.0 0.07 22.0 0.06 26.0 0.00 SCS TR-55 Existing Unit Hydrograph (DA D) 0 5 10 15 20 25 30 Site Outflow (DA A + DA B + DA D) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.21 12.0 0.94 12.1 2.91 12.2 2.04 12.3 1.17 12.4 0.84 12.5 0.69 12.6 0.58 12.7 0.50 12.8 0.45 13.0 0.40 13.2 0.36 13.4 0.33 13.6 0.30 13.8 0.28 14.0 0.26 14.3 0.23 14.6 0.23 15.0 0.21 15.5 0.19 16.0 0.17 16.5 0.16 17.0 0.16 17.5 0.15 18.0 0.14 19.0 0.13 20.0 0.11 22.0 0.10 26.0 0.00 3.50 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A+B+D) Site Outflow (DA A + DA B + DA D) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.01 11.3 0.01 11.6 0.01 11.9 0.71 12.0 2.67 12.1 5.62 12.2 3.78 12.3 2.00 12.4 1.41 12.5 1.15 12.6 0.95 12.7 0.80 12.8 0.71 13.0 0.63 13.2 0.55 13.4 0.50 13.6 0.46 13.8 0.43 14.0 0.39 14.3 0.35 14.6 0.34 15.0 0.31 15.5 0.28 16.0 0.25 16.5 0.23 17.0 0.22 17.5 0.21 18.0 0.20 19.0 0.18 20.0 0.15 22.0 0.14 26.0 0.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A+B+D) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Site Outflow (DA A + DA B + DA D) Hydrograph Time(hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.17 11.3 0.24 11.6 0.37 11.9 3.51 12.0 9.36 12.1 15.82 12.2 10.69 12.3 5.03 12.4 3.38 12.5 2.69 12.6 2.22 12.7 1.85 12.8 1.63 13.0 1.41 13.2 1.23 13.4 1.11 13.6 1.01 13.8 0.93 14.0 0.84 14.3 0.76 14.6 0.72 15.0 0.66 15.5 0.59 16.0 0.53 16.5 0.48 17.0 0.46 17.5 0.43 18.0 0.42 19.0 0.36 20.0 0.31 22.0 0.29 26.0 0.00 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A+B+D) Channel and Flood Protection Calculations The following calculations show how Subareas A and C meet Channel and Flood Protection requirements, while also demonstrating how offsite upland flow from Subarea D is taken into account in the calculations for the routings and outflow hydrographs. U.S. Department of Agriculture Natural Resources Conservation Service Project: Victorian Heights Location: Berkmar Drive Check One: Present X 1. Runoff curve Number (CN) Developed TR 55 Worksheet 2: Runoff Curve Number and Runoff Designed By: LMW, PE Checked By: SRC, PE FL-ENG-21A 06/04 Date: 12/16/2021 Date: 12/16/2021 Cover description CN (weighted) _Calculated Drainage Area Soil name and hydrologic (Cover type, treatment, and hydrologic condition; percent CN Area Product of CN x total product/ 'S' Description group (Appendix A) (Acres) Area Value impervious; unconnected/ connected impervious area ratio) total area Impervious Areas 98 0.21 20.6 DAA B Lawns in Good Condition (25%+/-) 61 0.29 17.7 62 6.13 (Pre-Dev.) Woods Grass Good Condition 58 1.81 105.0 Impervious Areas 98 0.14 13.7 DAB B Lawns in Good Condition (25%+/-) 61 0.50 30.5 60 6.54 (Pre-Dev.) Woods Grass Good Condition 58 1 2.26 131.1 Impervious Areas 98 3.02 295.6 DAA (Post-Dev) B Lawns in Good Condition 61 1.54 93.9 85 1.70 Woods Grass Good Condition SS 0.00 0.0 DAC Impervious Areas 98 0.08 7.8 (Post-Dev) B Lawns in Good Condition 61 0.57 34.8 66 5.25 Woods Grass Good Condition 58 0.00 0.0 DAD Impervious Areas 98 0.21 20.6 (Existing Offsite- B Lawns in Good Condition 61 1.00 61.0 67 4.83 Outside LOD) lWoods Grass Good Condition 58 0.00 0.0 2. Runoff 1-Year Storm 2-Year Storm 10-Year Storm Drainage Area Description Frequency -years 1 2 10 n/a Rainfall, P (24 hour)- inches 3.00 3.63 5.48 n/a Runoff, Q-inches 0.40 0.68 1.74 DA A(Pre-Dev.) Runoff, Q-inches 0.35 0.61 1.62 DA B(Pre-Dev) Runoff, Q-inches 1.62 2.17 3.86 DA A(Post-Dev) Runoff, Q- inches 0.53 0.85 2.03 DA C(Post-Dev) Runoff, Q- inches 0.60 0.95 2.18 DA D(Existing Offsite-Outside LOD) U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 3: Time of Concentration (Tc) or Travel Time (T,) Project: Victorian Heights Location: Berkmar Drive Check One: Present X Developed Check One: T, X T, Sheet Flow: (Applicable to Tc only) X Segment ID, 1 Surface description (Table 3-1) 2 Manning's roughness coeff., n (Table 3-1) 3 Flow length, L (total L < 100) (ft) 4 Two-year 24-hour rainfall, P,(in.) 5 Land slope, s (ft/ft) 6 Compute T, _ [0.007(n*Lf 81 / Pi S s°.a Shallow Concentrated Flow Designed By: Checked By: n/a FL-ENG-21A 06/04 Date: 12/16/2021 Date: 12/16/2021 DA A DA B DA A DA C DA D (Pre-Dev.) (Pre-Dev.) (Post-Dev) (Post-Dev) (Existing Offsite- Outside LOD) Smooth Smooth Smooth Smooth Surface Surface Surface Surface Grass -dense 0.011 0.011 0.011 0.011 0.24 15 25 100 45 54 3.63 3.63 3.63 3.63 3.63 0.02 0.02 0.01 0.09 0.02 0.00 0.01 0.03 0.01 0.14 7 Surface description (paved or unpaved) Unpaved Unpaved Paved Paved Unpaved 8 Flow Length, L (ft) 400 265 161 73 690 9 Watercourse slope, s (ft/ft) 0.08 0.17 0.01 0.01 0.03 10 Average velocity, V (Figure 3-1) (ft/s) 4.6 6.5 1.3 2.3 2.7 11 T,=L/3600*V 0.02 0.01 0.03 0.01 0.07 Channel Flow: 12 Cross sectional flow area, a (ft) 13 Wetted perimeter, Pw (ft) 14 Hydraulic radius, r = a/Pw (ft) 15 Channel Slope, s (ft/ft) 16 Manning's Roughness Coeff, n 17V=[1.49r/Y']/n 18 Flow length, L (ft) 19 T,= L / 3600*V 20 Watershed or subarea Tc or T, (Add T, in steps 6, 11 and 19) 0.10 1 0.10 1 0.10 1 0.10 1 0.21 TR 55 Graphical Peak Discharge Method Project: Victorian Heights Date: 12/16/2021 Location: Berkmar Drive Date: 12/16/2021 Check One: PresenX DcnX 1. Data Drainage Area Description Drainage Area Description Drainage Area Description Drainage Area Description Drainage Area Description DAA (Pre-Dev.) DAB (Pre-Dev.) DAA (Past-Dev) DAC (Post-Dev) DAD (Existing Offsite-Outside LOD) Drainage Area (Am) in miles' 0.0036 0.0045 0.0071 0.0010 0.0019 Runoff curve number CN= 62 60 85 66 67 Time of concentration(Tc)= 0.10 0.10 0.20 0.10 0.21 Rainfall distribution type= Type II Type II Type II Type II Type II Pond and swamp areas spread throughout the watershed= 0 0 0 0 0 2. Frequency -years 1 2 10 1 2 10 1 2 10 1 2 10 1 2 10 3. Rainfall, P (24 hour)- inches 3.00 3.63 5.48 3.00 3.63 5.48 3.00 3.63 5.48 3.00 3.63 5.48 3.00 3.63 5.48 4. Initial Abstraction, la -inches 1.23 1.23 1.23 1.31 1.31 1.31 0.35 0.35 0.35 1.05 1.05 1.05 0.97 0.97 0.97 5. Compute la/P 0.41 0.34 0.22 0." 0.36 0.24 0.12 0.10 0.06 0.35 0.29 0.19 0.32 0.27 0.18 6. Unit peak discharge, Qu-am/in Out of Range. Hydrograph for See Flows Out of Range. Hydrograph for See Flows Out of Range. See Hydrograph for Flows Out of Range. Hydrograph for See Flows Out of Range. Hydrograph for See Flows ]. Runoff, Q from Worksheet 2-inches 0.40 0.68 1.74 0.35 0.61 1.62 1.62 2.17 3.86 0.53 0.85 2.03 0.60 0.95 2.18 8. Pond and Swamp adjustment factor, Fp 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 9. Peak Discharge, Qp-cfs where Qp=Qu Am QFp 1.15 2.23 6.11 1.22 2.42 ].10 Routed thmugh Underground Detention Basin 1 1 0.45 0.81 2.01 WATERSHED SUMMARY Area, 1-year Flow, 2-year Flow, 10-year Flow, CN ac. cts cfs cfs FDA A+B+D(Pre-Dev) 62 6.42 2.91 5.62 15.82 Area, 1-year Flow, 2-year Flow, 10-year Flow, CN ac. cfs Cf. cfs DAA+C+D(Post-Dev) 80 6.42 1.13 5.48 15.65 WATERSHED SUMMARY FOR CHANNEL PROTECTION Area, 1-year Flow, 2-year Flow, 10-year Flow, CN ac. cf$ cfs Cfs FDA A+B(Pre-Dev) 61 5.21 2.37 2.37 13.21 CN Area, ac. DA A + C (Post-Dev) 83 5.21 Area, 1-year Flow, 2-year Flow, 10-year Flow, CN ac. cfs cis cis DA D (Existing Offsite Outside LOD) 67 1.21 0.74 1.25 3.07 9 VAC 25-870-66 Section B: Channel Protection Utilizing a 1-inch Orifice "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet the criteria in subdivision 1, 2 or 3 of this subsection..." Section B.1: Manmade stormwater conveyance systems "When stormwater from a development is discharged to a manmade stormwater conveyance system, following the land -disturbing activity, either..." a. or b. shall be met: Section B.l.b. "The peak discharge requirements for concentrated stormwater flow to natural stormwater conveyance systems in subdivision 3 of this subsection shall be met." Section 8.3 "... the maximum peak flow rate from the one-year 24-hour storm following the land -disturbing activity shall be calculated either.." a. or b." Section 6.3.a. In accordance with the following methodology: Q Allowed < I.F. * (Q Pre -Developed + (RV Pre -Developed) ) I (RV Developed ) + Q Pre -Developed Offsite Q Allowed < 1.23 cfs Where: QPre-Developed= CN Pre -Developed= S Pre -Developed = RV Pre -Developed — CN Post -Developed= S Post -Developed = RV Port -Developed= I.F. = Q Pre -Developed Offsite = Q Developed 2.37 cfs (From TR-55) 61 (From Curve Number Summary) 6.29 (From SCS TR-55 eq. 2-4) 0.38 in. (From SCS TR-55 eq. 2-3) 83 (From Curve Number Summary) 2.05 (From SCS TR-55 eq. 2-4) 1.45 in. (From SCS TR-55 eq. 2-3) 0.80 (Factor of Safety) 0.74 cfs (From TR-55) = 1.13 cfs Section B.4 Limits of Analysis The analysis terminates at Post -Development Subarea A+C since subsection B.3.a is met. 9 VAC 25-870-66 Section C: Flood Protection "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet one of the following criteria as demonstrated by use of acceptable hydrologic and hydraulic methodologies:" Section C.2.b.: The point of discharge (Detention Basin B's Outfall), "releases a postdevelopment peak flow rate for the 10-year 24-hour storm event that is less than the predevelopment peak flow rate from the 10-year 24-hour storm event. Downstream stormwater conveyance systems do not require any additional analysis to show compliance with flood protection criteria if this option is utilized." 10-Year, 24-Hour Pre -Development Subareas A, B & D Peak Flow Rate = 15.82 cfs 10-Year, 24-Hour Post -Development Subarea A, C & D Peak Flow Rate = 15.65 cfs Section C.3 Limits of Analysis The flood protection analysis terminates at Subarea A+C since subsection C.2.b is met. Post -Development Detention Basin Routings and Outflow Hydrographs The following routing calculations and outflow hydrographs reflect the post -development attenuation in Subarea A from the proposed underground detention facility. Post -Development DA A Inflow Hydrograph Time (hrs) Inflow (cfs) 0.0 0.00 0.5 0.07 1.0 0.08 1.5 0.08 2.0 0.09 2.5 0.09 3.0 0.10 3.5 0.10 4.0 0.10 4.5 0.11 5.0 0.12 5.5 0.12 6.0 0.13 6.5 0.13 7.0 0.15 7.5 0.15 8.0 0.16 8.5 0.19 9.0 0.23 9.5 0.23 10.0 0.28 10.5 0.37 11.0 0.51 11.3 0.69 11.6 1.61 11.9 9.19 12.0 3.96 12.1 2.44 12.2 1.32 12.3 1.08 12.4 0.92 12.5 0.75 12.6 0.63 12.7 0.59 12.8 0.55 13.0 0.47 13.2 0.41 13.4 0.38 13.6 0.34 13.8 0.31 14.0 0.28 14.3 0.26 14.6 0.24 15.0 0.22 15.5 0.20 16.0 0.17 16.5 0.16 17.0 0.15 17.5 0.15 18.0 0.13 19.0 0.11 20.0 0.10 22.0 0.09 26.0 0.00 26.5 0.00 27.0 0.00 27.5 0.00 10.00 8.00 6.00 4.00 2.00 0.00 -2.00 Inflow Hydrograph (1-yr Design Storm) Post -Development DA A Inflow Hydrograph 0.0 0.00 0.5 0.10 1.0 0.11 1.5 0.11 2.0 0.12 2.5 0.12 3.0 0.13 3.5 0.13 4.0 0.14 4.5 0.15 5.0 0.16 5.5 0.16 6.0 0.18 6.5 0.18 7.0 0.20 7.5 0.21 8.0 0.22 8.5 0.26 9.0 0.31 9.5 0.31 10.0 0.38 10.5 0.49 11.0 0.68 11.3 0.92 11.6 2.16 11.9 12.33 12.0 9.81 12.1 3.27 12.2 1.78 12.3 1.45 12.4 1.23 12.5 1.00 12.6 0.85 12.7 0.79 12.8 0.73 13.0 0.63 13.2 0.56 13.4 0.51 13.6 0.45 13.8 0.42 14.0 0.38 14.3 0.34 14.6 0.33 15.0 0.30 15.5 0.26 16.0 0.23 16.5 0.22 17.0 0.21 17.5 0.19 18.0 0.18 19.0 0.15 20.0 0.13 22.0 0.12 26.0 0.00 26.5 0.00 27.0 0.00 27.5 0.00 14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 -2.00 Inflow Hydrograph (2-yr Design Storm) 1.0 Past -Development DA A Inflow Hydrograph Time (hrs) Inflow (cfs) 0.0 0.00 0.5 0.18 1.0 0.19 1.5 0.20 2.0 0.21 2.5 0.21 3.0 0.23 3.5 0.23 4.0 0.25 4.5 0.26 5.0 0.28 5.5 0.28 6.0 0.32 6.5 0.32 7.0 0.35 7.5 0.37 8.0 0.39 8.5 0.46 9.0 0.55 9.5 0.56 10.0 0.68 10.5 0.89 11.0 1.22 11.3 1.65 11.6 3.86 11.9 22.07 12.0 19.77 12.1 5.86 12.2 3.18 12.3 2.60 12.4 2.21 12.5 1.80 12.6 1.52 12.7 1.42 12.8 1.32 13.0 1.14 13.2 1.00 13.4 0.92 13.6 0.81 13.8 0.74 14.0 0.67 14.3 0.62 14.6 0.58 15.0 0.53 15.5 0.47 16.0 0.41 16.5 0.39 17.0 0.37 17.5 0.35 18.0 0.32 19.0 0.27 20.0 0.23 22.0 0.21 26.0 0.00 26.5 0.00 27.0 0.00 27.5 0.00 25.00 20.00 15.00 10.00 5.00 0.00 -5.00 Inflow Hydrograph (10-yr Design Storm) Post -Development DA A+ D Inflow Hydrograph (To Underground Detention) Time (hrs) Inflow (cfs) 0.0 0.00 11.0 0.51 11.3 0.69 11.6 1.61 11.9 9.23 12.0 4.13 12.1 2.98 12.2 2.06 12.3 1.63 12.4 1.24 12.5 0.98 12.6 0.82 12.7 0.75 12.8 0.68 13.0 0.59 13.2 0.52 13.4 0.47 13.6 0.42 13.8 0.39 14.0 0.35 14.3 0.32 14.6 0.30 15.0 0.28 15.5 0.25 16.0 0.22 16.5 0.21 17.0 0.20 17.5 0.19 18.0 0.17 19.0 0.15 20.0 0.13 22.0 0.12 26.0 0.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 Inflow Hydrograph (1-yr Design Storm) Post -Development DA A+ D Inflow Hydrograph (To Underground Detention) Time (hrs) Inflow (cfs) 0.0 0.00 11.0 0.69 11.3 0.93 11.6 2.17 11.9 12.44 12.0 10.17 12.1 4.25 12.2 3.02 12.3 2.35 12.4 1.75 12.5 1.37 12.6 1.14 12.7 1.02 12.8 0.93 13.0 0.80 13.2 0.70 13.4 0.64 13.6 0.57 13.8 0.52 14.0 0.47 14.3 0.43 14.6 0.40 15.0 0.37 15.5 0.33 16.0 0.29 16.5 0.27 17.0 0.26 17.5 0.24 18.0 0.22 19.0 0.19 20.0 0.16 22.0 0.15 26.0 0.00 Inflow Hydrograph (2-yr Design Storm) Post -Development DA A+ D Inflow Hydrograph (To Underground Detention) Time (hrs) Inflow (cfs) 0.0 0.00 11.0 1.27 11.3 1.73 11.6 3.97 11.9 22.62 12.0 21.00 12.1 8.47 12.2 6.25 12.3 4.66 12.4 3.36 12.5 2.58 12.6 2.13 12.7 1.90 12.8 1.72 13.0 1.47 13.2 1.28 13.4 1.17 13.6 1.05 13.8 0.95 14.0 0.87 14.3 0.79 14.6 0.74 15.0 0.67 15.5 0.60 16.0 0.52 16.5 0.49 17.0 0.47 17.5 0.44 18.0 0.41 19.0 0.35 20.0 0.30 22.0 0.27 26.0 0.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 Inflow Hydrograph (10-yr Design Storm) BasinFlow printout INPUT: Basin: 0 Contour Areas Elevation(ft) Area(sf) Computed Vol.(cy) 3 Storage Pipes Storage pipe 0 name: name diameter (in) 120.000 length (ft) 113.000 invert (ft) 506.565 angle 0.287 volume (cy) 328.704 Storage pipe 1 name: name diameter (in) 120.000 length (ft) 113.000 invert (ft) 506.500 angle 0.287 volume (cy) 328.704 Storage pipe 2 name: name diameter (in) 120.000 length (ft) 126.000 invert (ft) 506.500 angle 0.287 volume (cy) 366.519 Start—Elevation(ft) 506.50 Vol.(cy) 5 Outlet Structures Outlet structure 0 Orifice name: BARREL area (sf) 1.227 diameter or depth (in) 15.000 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 506.400 multiple 1 discharge out of riser Outlet structure 1 Orifice name: LOW-RISE ORIFICE area (sf) 0.067 diameter or depth (in) 3.500 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 506.500 multiple 1 discharge into riser Outlet structure 2 Orifice name: EMERGENCY BYPASS PIPE area diameter or depth width for rect. coeffi invert mul discharge Outlet structure 3 Orifice (sf) 1.227 (in) 15.000 (in) 0.000 -ient 0.600 (ft) 515.000 tiple 1 out of riser name: MID -RISE ORIFICE area (sf) 1.250 diameter or depth (in) 12.000 width for rect. (in) 15.000 coefficient 0.600 invert (ft) 511.900 multiple 1 discharge into riser Outlet structure 4 Orifice name: OVERFLOW WEIR area (sf) 1.469 diameter or depth (in) 16.410 width for rect. (in) 0.000 coefficient 0.600 invert (ft) 516.000 multiple 1 discharge into riser 3 Inflow Hydrographs Hydrograph 0 Curve name: 1 YR UGD A INFLOW time incr (minlhrs) 0.02 time limit (minlhrs) 30.00 file: Q:\Projects\202196 - Victorian Heights\Calculations\SWM\3rd Sub\1 YR UGD A.txt volume (cy) 1225.11 routed true time in hours true Hydrograph 1 Curve name: 2 YR UGD A INFLOW time incr (minlhrs) 0.02 time limit (minlhrs) 30.00 file: Q:\Projects\202196 Sub\2 YR UGD A.txt volume (cy) 1717.06 routed true time in hours true Hydrograph 2 Curve name: 10 YR UGD A INFLOW time incr (minlhrs) 0.02 time limit (minlhrs) 30.00 file: Q:\Projects\202196 Sub\10 YR UGD A.txt volume (cy) 3211.08 routed true time in hours true OUTPUT: Routing Method: storage -indication - Victorian Heights\Calculations\SWM\3rd - Victorian Heights\Calculations\SWM\3rd Hydrograph 0 Routing Summary of Peaks: 1 YR UGD A INFLOW inflow (cfs) 9.227 at 11.90 (hrs) discharge (cfs) 0.718 at 12.64 (hrs) water level (ft) 511.629 at 12.74 (hrs) storage (cy) 487.606 Hydrograph 1 Routing Summary of Peaks: 2 YR UGD A INFLOW inflow (cfs) 12.439 at 11.90 (hrs) discharge (cfs) 4.672 at 12.10 (hrs) water level (ft) 512.815 at 12.10 (hrs) storage (cy) 641.222 Hydrograph 2 Routing Summary of Peaks: 10 YR UGD A INFLOW inflow (cfs) 22.624 at 11.90 (hrs) discharge (cfs) 14.389 at 12.04 (hrs) water level (ft) 516.468 at 12.04 (hrs) storage (cy) 1011.722 Post -Development Site Outflow Hydrographs The following outflow hydrographs reflect the post -development outflow from the site by adding the hydrographs for Subarea A (from detention routings), Subarea C (undetained) and Subarea D (offsite upstream flow that runs through site). Post -Development DA A+D Outflow Hydrograph (From Underground Detention Routings) Time (hrs) Outflow (cfs) 0.0 0.00 11.0 0.39 11.3 0.40 11.6 0.44 11.9 0.61 12.0 0.66 12.1 0.69 12.2 0.70 12.3 0.71 12.4 0.71 12.5 0.72 12.6 0.72 12.7 0.72 12.8 0.72 13.0 0.72 13.2 0.71 13.4 0.71 13.6 0.71 13.8 0.70 14.0 0.70 14.3 0.69 14.6 0.68 15.0 0.67 15.5 0.65 16.0 0.64 16.5 0.62 17.0 0.60 17.5 0.58 18.0 0.56 19.0 0.52 20.0 0.47 22.0 0.37 26.0 0.00 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 Outflow Hydrograph (1-yr Design Storm) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Post -Development DA A+D Outflow Hydrograph (From Underground Detention Routings) Time (hrs) Outflow (cfs) 0.0 0.00 11.0 0.46 11.3 0.48 11.6 0.52 11.9 0.70 12.0 2.34 12.1 4.67 12.2 4.32 12.3 3.21 12.4 2.74 12.5 2.29 12.6 1.92 12.7 1.65 12.8 1.44 13.0 1.16 13.2 0.97 13.4 0.84 13.6 0.76 13.8 0.74 14.0 0.73 14.3 0.73 14.6 0.72 15.0 0.71 15.5 0.70 16.0 0.68 16.5 0.67 17.0 0.65 17.5 0.63 18.0 0.62 19.0 0.58 20.0 0.54 22.0 0.45 26.0 0.17 27.0 0.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 Outflow Hydrograph (2-yr Design Storm) 0.0 5.0 10.0 15.0 20.0 25.0 30.0 Post -Development DA A+D Outflow Hydrograph (From Underground Detention Routings) Time (hrs) Outflow (cfs) 0.0 0.00 11.0 0.66 11.3 0.68 11.6 0.73 11.9 9.88 12.0 14.39 12.1 12.62 12.2 11.26 12.3 9.94 12.4 8.55 12.5 7.12 12.6 5.69 12.7 4.38 12.8 2.92 13.0 2.10 13.2 1.68 13.4 1.44 13.6 1.28 13.8 1.13 14.0 1.01 14.3 0.88 14.6 0.79 15.0 0.74 15.5 0.73 16.0 0.73 16.5 0.72 17.0 0.71 17.5 0.70 18.0 0.69 19.0 0.67 20.0 0.64 22.0 0.58 26.0 0.38 27.0 0.30 30.0 0.00 16.0^ 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 Outflow Hydrograph (10-yr Design Storm) Worksheet 5b (Modified for Clarity): Basic watershed Data 1-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA C 0.10 0.10 0.35 0.0005 (Post-Dev) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.06 12.0 0.24 12.1 0.45 12.2 0.26 12.3 0.11 12.4 0.09 12.5 0.08 12.6 0.07 12.7 0.06 12.8 0.05 13.0 0.05 13.2 0.04 13.4 0.04 13.6 0.04 13.8 0.03 14.0 0.03 14.3 0.03 14.6 0.03 15.0 0.02 15.5 0.02 16.0 0.02 16.5 0.02 17.0 0.02 17.5 0.02 18.0 0.02 19.0 0.01 20.0 0.01 22.0 0.01 26.0 0.00 6 5 4 3 2 1 0 SCS TR-55 Post-ReDevelopment Unit Hydrograph (ON DA Q 0 5 10 15 20 25 30 Worksheet 5b (Modified for Clarity): Basic watershed Data 2-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA C 0.10 0.10 0.29 0.0009 (Post-Dev) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.00 11.3 0.00 11.6 0.00 11.9 0.14 12.0 0.49 12.1 0.81 12.2 0.46 12.3 0.19 12.4 0.15 12.5 0.13 12.6 0.11 12.7 0.09 12.8 0.08 13.0 0.07 13.2 0.06 13.4 0.06 13.6 0.05 13.8 0.05 14.0 0.05 14.3 0.04 14.6 0.04 15.0 0.04 15.5 0.03 16.0 0.03 16.5 0.03 17.0 0.03 17.5 0.02 18.0 0.02 19.0 0.02 20.0 0.02 22.0 0.02 26.0 0.00 SCS TR-55 Post-ReDevelopment Unit Hydrograph (ON DA C) Worksheet 5b (Modified for Clarity): Basic watershed Data 10-yr. 24-hr. SCS TR-55 Method Unit Hydrograph for the la/P & Tc Listed Below Subarea Tc (hrs.) Tt (hr.) la / P Am*Q (mi2-in) DA C 0.10 0.10 0.19 0.0021 (Post-Dev) Hydrograph Time (hrs.) 10-yr Discharges (cn) 0.0 0.00 11.0 0.03 11.3 0.04 11.6 0.06 11.9 0.52 12.0 1.26 12.1 2.01 12.2 1.19 12.3 0.45 12.4 0.33 12.5 0.28 12.6 0.23 12.7 0.20 12.8 0.18 13.0 0.15 13.2 0.13 13.4 0.12 13.6 0.11 13.8 0.10 14.0 0.09 14.3 0.08 14.6 0.08 15.0 0.07 15.5 0.06 16.0 0.06 16.5 0.05 17.0 0.05 17.5 0.05 18.0 0.05 19.0 0.04 20.0 0.03 22.0 0.03 26.0 0.00 EI SCS TR-55 Post -Re Development Unit Hydrograph (ON DA C) 30 Site Outflow (DA A+ DA C + DA D) Hydrograph Time(hrs.) 1-yr Discharges (cfs) 0.0 0.00 11.0 0.39 11.3 0.40 11.6 0.44 11.9 0.67 12.0 0.90 12.1 1.13 12.2 0.96 12.3 0.82 12.4 0.80 12.5 0.80 12.6 0.79 12.7 0.78 12.8 0.77 13.0 0.76 13.2 0.76 13.4 0.75 13.6 0.74 13.8 0.74 14.0 0.73 14.3 0.72 14.6 0.71 15.0 0.69 15.5 0.67 16.0 0.65 16.5 0.64 17.0 0.62 17.5 0.60 18.0 0.57 19.0 0.53 20.0 0.48 22.0 0.38 26.0 0.00 1.20 SCS TR-55 Post -Re Development Unit Hydrograph (ON DA A+C+D) Site Outflow (DA A + DA C + DA D) Hydrograph Time(hrs.) 2-yr Discharges (cfs) 0.0 0.00 11.0 0.46 11.3 0.48 11.6 0.52 11.9 0.84 12.0 2.84 12.1 5.48 12.2 4.77 12.3 3.39 12.4 2.89 12.5 2.42 12.6 2.03 12.7 1.74 12.8 1.53 13.0 1.23 13.2 1.03 13.4 0.89 13.6 0.81 13.8 0.78 14.0 0.78 14.3 0.77 14.6 0.76 15.0 0.74 15.5 0.73 16.0 0.71 16.5 0.69 17.0 0.67 17.5 0.66 18.0 0.64 19.0 0.60 20.0 0.55 22.0 0.47 26.0 0.17 27.0 0.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 SCS TR-55 Post-ReDevelopment Unit Hydrograph (ON DA A+C+D) Site Outflow (DA A + DA C + DA D) Hydrograph Time(hrs.) 10-yr Discharges (cfs) 0.0 0.00 11.0 0.69 11.3 0.72 11.6 0.79 11.9 10.40 12.0 15.65 12.1 14.63 12.2 12.45 12.3 10.38 12.4 8.88 12.5 7.40 12.6 5.93 12.7 4.58 12.8 3.09 13.0 2.26 13.2 1.82 13.4 1.56 13.6 1.39 13.8 1.23 14.0 1.10 14.3 0.96 14.6 0.87 15.0 0.81 15.5 0.80 16.0 0.78 16.5 0.77 17.0 0.76 17.5 0.75 18.0 0.74 19.0 0.71 20.0 0.67 22.0 0.61 26.0 0.38 27.0 0.30 30.0 0.00 SCS TR-55 Pre-ReDevelopment Unit Hydrograph (ON DA A+C+D) STORM SEWER COMPUTATIONS For outfall from UGD to existing pipe 10 YEAR STORM SEWER COMPUTATIONS Design Storm Year= 10 FOINT OOWNSiREAM STRUC VSE DRAM AREA RUNOFF COEFF_ CA INLE! Tlh® RAM FALL RUNOFF Q INVERT ELEVATIONS LENGTH SLOFE CIA CAPA- C. VEL FLOW llF® REMARK$ INCR ACCUM ACRES C MM MM FFS. UFPE0. LOWER FEEF FLFT. MCHES CFS. FPS. SEC DGD 0.00 0.90 0.00 0.00 5.00 6.67 14.4 4 506.48 505.71 35.00 0.0220 18 16.9 10.7 3.3 4 0.00 0.90 0.00 0.00 5.05 6.65 14.4 3 505.61 503.96 92.08 0.0179 18 15.2 9.8 9.4 3 0.00 0.90 0.00 0.00 5.21 6.60 14.4 2 503.86 500.29 63.54 0.0562 18 27.0 15.4 4.1 2 0.00 0.90 0.00 0.00 5.28 6.58 14.4 1 500.19 496.36 40.80 0.0939 18 34.9 18.6 2.2 1 0.00 0.90 0.00 0.00 5.32 6.57 14.4 OUT 496.11 485.74 103.41 0.1003 18 33.3 18.0 5.8 Hydraulic Grade Line Calculation Design Year: 10 Project: Victorian Heights Job #: 202196 Prepared by: LMW, PE WEFT STATION OU TWATER SURFACE ELEV Da Q. ZW Se He [ ID CnONLOSS ................................................................... 3.............................................................. V, Ile Qx Vx QiV, V�/18 H. ANGLE He IG 13H, 5K '�,. FMA H WLET WATERS SURFACE ELEV RM ELEV 486.94 103.41 18 14.39 0.019 1.94 18.0 1.3 1 14.4 18.6 268 5.4 1.89 65 2,96556 6.11 7.94 3.97 5.91 492.85 501.00 497.56 40.80 18 14.39 0.016 0.65 18.6 1.3 2 14.4 15.4 221 3.7 1.29 8 0 2.64 3.43 1.71 2.37 499.93 505.36 501.49 1 63.54 18 1 14.39 1 0.016 1.02 15.4 0.9 3 14.4 9.8 141 1.5 0.52 0 0 1.44 1.87 0.94 1.95 503.44 523.91 505.16 92.08 18 14.39 0.016 1.47 9.8 0.4 4 14.4 10.7 154 L8 1 0.62 0 0 0.99 1.29 0.65 2.12 1 507.28 1 525.07 507.28 35.00 18 14.39 0.016 0.56 10.7 0.4 UGD 0.00 0 0 0.44 0.58 0.29 0.85 508.13 528.50 Hydraulic Grade Line Page 1 Virginia Runoff Reduction Method Water Quality Calculations (COMPLIANCE IS MET THROUGH THE BEST MANAGEMENT PRACTICE OF PURCHASING NUTRIENT CREDITS. THE VRRM BOUNDARY IS DEFINED BY THE LIMITS OF DISTURBANCE) Om W9Bdo OunaAxduRbnrta dr Oave/pP mWftnmyneadineee- ♦ 2011BMPMaMaN Sptl0odms OM130 BMP 3tandasdsaM 3Ped0olbns PJl Name: M mdan Hei6Ms Oa@: 12/9/2021 BMPOesign SPe[ifirmiam Lis[ 2013 MA Stds & Spea Ons dots a,mranprcna.l 43 awan E.msnnC 1.m TM I m: pPllMcye nxs �mm+ItMCImW 1.M is rgetm Wea 114/eve/yr� 0A] rllunma::mnam.eem.l o.m 3.0 Site Results (Water Quality Compliance) Area Checks FOREST/OPEN SPACE (a[) D.A.A am D.A.B 0.00 D.A.0 0.00 DA.D 0.DO O.F.E O.W A.-CHEM OK. IMPERVIOUS COVER(a[) am 0.00 0.00 0.00 0.00 OK. IMPERV��GED TUEAAREA Ia[) 0.00 0.00 DOD 0.00 0.00 OK. MANAGED TURF AREA TREATED Ia[) 0.00 0.00 DOD 0.00 O.00 OK. AREA CHECK OK OK. OK. OK OK. Site Treatment Volume (ks) 12,191 Runoff Reduction Volume and TP By Drainage Area D.A. A D.A. B___j D.A. C D.A. D O.A. E TOTAL RUNOFF VOLUME ACHIEVED 0 0 0 0 0 LOADAUOION (lb/ TP LOADAVAINBLE FOR REMOVAL Qb/yrl 0.00 O.W 0.00 � 0.00 O.M 0.00 TPIDADREDUCnONACHIEVED)Ib/yrl 0.00 O.00 DOD 0.00 O.W 0.00 TP LOAD REMAINING IIb/yr) 0.00 O.W 0.00 0.00 O.W am MMOGEN LOAD REDUCTION ACHIEVED pb/yrl am 0.00 0.00 0.00 O.W 0.00 Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD (lb/yr)) 7.66 TP LOAD REDUCTION REQUIRED pb/yrl 5.56 TP WAD REDUCTION AOIIFVED lb/yr) 0.00 W WAD REM =(I(b/N):1 7.66 REMAINING TP LOAD REDUCTION REQUIRED (IbIW):l 5.56 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD IIb/yr) I 5 Ao NITROGEN LOAD REDUCTION ACHIEVED Pb/yrl am REMAINING POST -DEVELOPMENT NITRWEN LOAD Pb/yrl 50.60 4E4 Ygim'a RungjRMUN'w MCMatl Rn4eeelapnenf Wlp'ianu SgeotlsM1eex - Version... M.tro' .ea.m.nasPealwma oxestrab,r.Pm.,mm..easaaRam. Pml .![bean P twuzmd linen,.—I.Pmen peon, xo Site Information Post -Development Project (Treatment Volume and Loads) Enter T¢talolsWrbea Frealoeres/ s13 cheek: -_ 9MP4es;yn9pen'fiev cross1 staa6 xo xoearreemoreo. enm ea � ram;emmee eae emeaex .d? � Pm..doeam lane lnwr dla.l _.._ nreNole oel�l-wmuma '.. --area—..mry '.., lgaeb�sm.rlasl yJx " 513 Port-0.,doan.rc umm -eee ns 1�1- ore. n � evrelommam pm m aeaaelmerel le�ymnnl�l-meeme,,— a mo�µM.rea '. lgaeb�smnl>sl iu ''. Ya4d a 9L K fnuYKK - euno taaaruwX[ Rv - - -- u.eailvnvl .l ,se&onse—r asaY [sW nfeya m IImed ra.m/ormmae nS manag.a.un nss 6m n11 nE vymlrmsl.c MrM1l ' r.re-1. uersn.,.noenlne.0 .e,.wawR..a trea.s.nerw mlm a` pnooa . .. ml -l.. n11 me ..EE-da.re—t a .,Tmr.,.. w.nme.a ¢m nm weigmee v.leM ¢m wegnery l^•II Are .e�eeTm .xN aN .Me..ae*m ara + s.�ee.m sa Imae.vr... y.esl ¢II nzz ni.us[mre.l+�resl lTx I�� me Dy py,oa, Mlmem+4 ¢a - nss s.R^'ceaw.l ¢9; ,re...+sc o9s a.Nm..m re.m. ,ma1�1 srs za r...ae .e.lo4 sn iea ,� u lom our Treatment Volume and Nutrient Load Treatment Volume and Nutrient Load a e ¢Gxo a nLO renmemvoia�re ¢x)59 e v. lum eaeila omu ne UxgB IRm g 1 wme.a.I.wlnmel namv.e 'ma ysss Trel mm�nv.�. .;.9x anan�vwa—M net—sed 4o' ---1 xe ;a., ed.rtnl� read e —e _ e 1.15 0.95 a wmem5 rma� M`n nt t an L versa anu bs (ammTma IIb/nIAT a0m. lo/rN r..wnurre�.re warm °a "� .m+I TP aae � nveeml m.awwy..r.er .mm.n ea olued—ardre dePeefoire. d.m xew sp m vee neI" Iwvd PoSt-Development Requirement for Site Area TP to,a Re9u[tion Repuirea llb/yTl 5.56 Iffam en Loads (Informational Purposes Only) nopame�naxml.allp5h fl13 re—x me-.., som lint Site Results (Water Quality Compliance) Area Checks O.A.A O.A.B O.A.0 A. D.A.E ARMECK FOREST/OVEN SPACE (a[) am O.W 0.00 i0.00 O.W OK. IMPERWOUS MVER (ac) IMPERVnMCOVERTRENTFD)ac) am 0.00 0.00 0.00 0.00 0.00�M. 0.00 OWOK. OK.. MANAGEDTURFAREA(a[) 0.00 O.00 0.00 00.W OK. MANAGED TURF AREA TREATED(a[) am O.00 0.00 0.00 OK. AREA CHECK OK OK. OK. OK. Site Treatment VOIUme (ffa) 11.191 Runoff Reduction Volume and TP By Drainage Area O.A. A O.A. C D.AD O.A. E TOTALRUNOFF REDUMM VOLUME ACHIEVED pF) 0 0 0 00 AL Qb/1) LOADAVAKABLE FNhh 0.00 MAI 0.00 0.000.0.00 TPIDADREOUCTIED pb/yr) 0.00 0.00 0.00 O.W am TP LOADNG )Ib/yr) 0.00 0.00 0.00 O.W am NMWGEN IDAD REDUCTIEDpb/yr) am O.W 0.00 0.00 O.W 0.00 Totphorus FINAL POST-DEVELOPMAD Qb/yr)WTPLOADREDUCTIED pb/yr�TPIDADREOUCTIED pb/yr)W LOADREMAINING Qb/,): REMAINING TP LOAD REDUCTION REQUIRED (lb/yr): 5.56 OUTFALL PROTECTION COMPUTATIONS