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WPO201900043 Calculations 2019-11-13
AutoZone COUNTY OF ALBEMARLE, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE JULY 16, 2019 REVISED: NOVEMBER 12, 2019 TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Ave, Suite 200 Charlottesville, VA 22903 434.327.1688 Table of Contents Section Title 1 Project Narrative 2 Pipe and Inlet Computations 3 Virginia Runoff Reduction Method Worksheet Summary 4 Pre & Post -Developed HydroCAD Calculations 5 Nutrient Credit Availability Letter Project Narrative: This project includes the construction of a new building, parking area, utilities, and associated site work. Limits of clearing and grading area is 1.33 acres. Water Quality Compliance: The disturbed area of 1.33 acres was used for the water quality analysis. In the proposed condition there will be 0.48 acres of managed turf and 0.85 acres of impervious cover. In the future development, there will be a total of 0.39 acres of managed turf and 0.94 acres of impervious cover. The 0.54 lb/yr of phosphorus removal required based on future development will be achieved through the purchase of nutrient credits. Water Quantity CoMpliance: Stormwater Quantity requirements for analysis point 1 will utilize a CMP detention system located within the parking area to meet all stormwater quantity requirements for this drainage area. Energy balance and channel protection for this analysis point are in compliance with all requirements. FORM LD 204 STORMWATER INLET COMPUTATIONS SHEET 1 OF 1 LD-204 ROUTE PROJECT Autozone DESIGNER: CG DATE 111812019 CHECKED. UNITS':NGLISH m INLET .❑, 42 ¢ E � �� wU h� y� `. �'� C Z ,✓� rn � �' '-. } � U.. Sag Inlets Only Q s°t✓ �� - �� 202 D1-313 4.000 0.170 0.69 0.1173 WRIGHT 0.117 4 0.468 0 0.468 0.0100 0.0256 2.560 2.000 0.7813 0.0833 3.2539 0.996 3.38 0.1410 0.1661 3.997 4.000 1.001 L000 0.468 0.000 2.171 206 D1-3B 4.000 0.220 0.81 0.1782 WRIGHT 0.178 4 0.712 0 0.712 0.0100 0.0195 4.148 2.000 0.4822 0.0833 4.2718 0.944 3.53 0.1471 0.1584 4.906 4.000 0.815 0.952 0.678 0.034 2.502 302 D1-3C 6.000 0 4 0 0 Back/Lt. 0.000'RIGH 0.250 0.74 0.185 Ahead/Rt. 0.185 4 0.74 0 0.001 0.0218 8.046 2.000 0.2486 0.0833 3.8211 3.48 Ahead/Rt. 0.740 0.001 6 0.740 1.246 0.174 0.333 0.52252 3.246 4.763 T > 8.0 ft 402 D1-313 4.000 0.220 0.87 0.1914 0.000'RIGHT 0.191 4 0.764 0 0.764 0.0100 0.0208 4.211 2.000 0.47 0.0833 4.0048 0.934 3.50 0.1458 0.1569 5.081 4.000 0.787 0.938 0.717 0.047 2.562 INLETSOFT BY ENSOFTEC DATE: 11/8/2019 LD-229 PROJECT: Autozone STORM SEWER DESIGN COMPUTATIONS LOCATION: Charlottesville COUNTY: Charlottesville STORM FREQUENCY 10 NOAA STATION: Designed by: CG Checked by: UNITS ENGLISH PIPE NO. FROM POINT TO POINT DRAIN. AREA "A" Aare 3 RUNOFF COEFF. "C" 4 CA TOTAL INLET TIME Minutes (7 RAIN FALL In/Hr 8 RUNOFF INVERT ELEVATIONS LENGTH of Pipe Ft. 12 SLOPE Ft./Ft. 13 SIZE (Dia. Or Span/Rise) In. 14 SHAPE Number of Pipes Capacity CFS 15 Friction Slope Ft./Ft. NORMALFLOW FLOW TIME Sec. 17 REMARKS (18) INCRE- MENT (5) ACCUM- ULATED 6 Lateral CFS Total Q CFS (9 UPPER END 10 LOWER END 11 Depth of Flow, do Ft. Area of Flow, An SgFt Hrn Ft. Vn Ft/Sec 16 En Ft. REFERENCE (1) STA. REFERENCE (2 STA. 101 102 100 0.00 0.00 0.08 5.17 6.49 0.00 6.87 451.75 451.44 62.81 0.00494 21 Circular 1 11.14 0.00200 0.99 1.41 0.47 4.87 1.36 12.90 103 SWM 102 0.00 0.00 0.00 5.00 0.00 0.00 6.87 452.10 451.85 36.78 0.00680 18 Circular 1 9.38 0.00380 0.95 1.18 0.43 5.80 1.48 6.34 201 202 SWM 0.17 0.69 0.12 0.37 5.52 6.38 0.00 2.68 455.63 455.42 21.27 0.00987 12 Circular 1 3.84 0.00510 0.62 0.51 0.28 5.28 1.05 4.03 203 204 202 0.00 0.00 0.25 5.16 6.49 0.00 1.94 456.70 455.63 106.22 0.01007 12 Circular 1 3.87 0.00260 0.50 0.39 0.25 4.93 0.88 21.53 205 206 204 0.22 0.81 0.18 0.18 5.00 6.54 0.00 1.16 457.50 456.80 36.10 0.01939 12 Circular 1 5.38 0.00100 0.32 0.21 0.18 5.47 0.78 6.60 301 302 SWM 0.25 0.74 0.19 0.19 5.00 6.54 0.00 1.21 459.47 454.83 155.40 0.02986 12 Circular 1 6.67 0.00100 0.29 0.19 0.17 6.45 0.94 24.08 401 402 SWM 0.22 0.87 0.19 0.19 5.00 6.54 0.00 1.25 457.25 456.16 24.14 0.04515 12 Circular 1 8.20 0.00110 0.26 0.17 0.15 755 1.15 3.20 RDl RD 204 0.16 0.90 0.14 0.14 5.00 6.54 0.00 0.94 458.75 457.79 51.67 0.01858 8 Circular 1 L7g 0.00540 0.34 1 0.18 1 0.17 1 5.18 1 0.76 1 9.97 LD-347 PROJECT: Autozone DESIGNED BY: CG HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION STA. INVERT EL. OUTFLOW PIPE DEPTH OF FLOW OUTFLOW PIPE OUTLET WATER SURFACE ELEV. DIA. PIPE Do In/mm DESIGN DISCH. Qo CFS/CMS LENGTH PIPE L. FVM) FRICTION SLOPE, Sfo (FT/FT) (M/M) FRICTION LOSS Hf (FVM JUNCTION LOSS SURFACE FLOW Adj. Ht 1.3 Ht (FVM Inlet Shaping? Y/N 0.5 Ht FVM FINAL H FVM Inlet Water Surface Elevation Top of MH Top of Inlet Elev. APPROX. Adjustment? Vo Contr. Ho FVM Vi Vi"2/2g Hi (Expn) 0.35"MAX. V12/2 SKEW Angle K Bend H FVM) Sum HL (FVM) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 17 18 19 100 452.750 102 451.440 1.75 452.840 21 6.870 62.81 0.00197 0.123 4.871 0.092 5.800 0.522 0.183 0.0 0.00 0.000 0.275 0.000 0.275 YES 0.137 0.261 453.101 459.500 O.K. SWM 451.850 1.50 453.101 18 6.870 36.78 0.00381 0.140 5.800 0.131 5.283 0.433 0.152 0.0 0.00 0.000 0.282 0.000 0.282 YES 0.141 0.281 453.382 461.800 O.K. 202 455.420 1.00 456.220 12 2.684 21.27 0.00506 0.108 5.283 0.108 4.934 0.378 0.132 0.0 0.00 0.000 0.241 0.746 0.313 YES 0.156 0.264 456.484 462.790 O.K. 204 455.630 1.00 456.484 12 1.938 106.22 0.00264 0.280 4.934 0.095 5.576 0.483 0.169 0.0 0.00 0.000 0.263 0.000 0.263 YES 0.132 0.412 457.200 463.940 O.K. 206 456.800 1.00 457.600 12 1.164 36.10 0.00095 0.034 5.466 0.116 0.000 0.000 0.000 0.0 0.00 0.000 0.116 1.164 0.151 YES 0.075 0.110 457.816 463.940 O.K. 302 454.830 1.00 455.630 12 1.210 155.40 0.00103 0.160 6.453 0.162 0.000 0.000 0.000 0.0 0.00 0.000 0.162 1.210 0.210 YES 0.105 0.265 459.758 463.700 O.K. 402 456.160 1.00 456.960 12 1.250 24.14 0.00110 0.026 7.548 0.221 0.000 0.000 0.000 0.0 0.00 0.000 0.221 1.250 0.288 YES 0.144 0.170 457.514 462.550 O.K. RD 457.790 0.67 458.323 8 1.295 51.67 0,01023 0,529 5.576 0.121 0.000 0.000 0.000 0.0 0.00 0.000 0.121 t0000 0.121 YES 0.060 0.589 459.171 464.700 O.K. Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2013 Draft Stds & Specs Site Summary Total Rainfall (in): 43 Total Disturbed Acreage: 1.33 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.46 0.46 35 Impervious Cover (acres) 0.00 0.00 0.00 0.87 0.87 65 1.33 100 Post-ReDevelopment Land Cover (acres) A soils B Soils C Soils D Soils Totals % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.39 0.39 29 Impervious Cover (acres) 0.00 0.00 0.00 0.94 0.94 71 1.33 100 Site Tv and Land Cover Nutrient Loads Final Post -Development Post- Post- Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment & New Im Impervious) p j (New Impervious) Site Rv 0.74 0.73 0.95 0.73 Treatment Volume (ft3) 3,596 3,354 241 3,354 TP Load (lb/yr) 2.26 2.11 0.15 2.11 Total TP Load Reduction Required (lb/yr) 0.54 0.42 0.12 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (lb/yr) 16.16 15.36 Site Compliance Summary Maximum % Reduction Required Below 20% Pre-ReDevelopment Load Total Runoff Volume Reduction (ft3) 0 Pre- FinalPost-Development Past-ReDevelopmentTP ReDevelopment TP Load per acre TP Load per acre Load per acre (Ib/acre/yr) (Ib/acre/yr) lb/acre r 1.67 1.70 1.67 Summary Print Virginia Runoff Reduction Method Worksheet Total TP Load Reduction Achieved (lb/yr)l 0.00 Total TN Load Reduction Achieved (lb/vr)I 0.00 Remaining Post Development TP Loadl 2.26 Remaining TP Load Reduction (Ib/yr)I 0.54 ------------------------------------------------------------------------------------------------------------------------------------------------------- Drainage Area Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Total Area (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Drainage Area Compliance Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total TP Load Reduced (lb/yr) 0.00 0.00 0.00 0.00 0.00 0.00 TN Load Reduced (lb/yr) 0.00 0.00 0.00 0.00 0.00 0.00 Drainage Area A Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious Cover BMP Treatment TP Load from Practice Credit Area Credit Area s Volume (ft) Upstream Untreated TP Load to Practice (Ibs) TP Removed (lb/yr) TP Remaining (lb/yr) Downstream Treatment to be Employed acres acres Practices (Ibs) Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. 0.00 Ib/ r Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area B Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious Cover BMP Treatment 1 TP Load from Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Credit Area I 3 Volume (ft ) Upstream to Practice (Ibs) (Ib/yr) (Ib/yr) to be Employed acres acres Practices Ibs Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Drainage Area C Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious Cover BMP Treatment TP Load from Practice Credit Area Credit Area I 3 Volume (ft) Upstream Untreated TP Load to Practice (Ibs) TP Removed (Ib/yr) TP Remaining (Ib/yr) Downstream Treatment to be Employed acres acres Practices (Ibs) Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. (Ib/yr) 0.00 Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area D Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious Cover BMP Treatment 1 TP Load from Practice Credit Area Credit Area I a Volume (ft ) Upstream Untreated TP Load to Practice (Ibs) TP Removed (Ib/yr) TP Remaining (Ib/yr) Downstream Treatment to be Employed acres acres practices Ibs Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. 0.00 Ib/ r Total TN Load Reduction Achieved in D.A. (Ib/yr) 0.00 Drainage Area E Summary Land Cover Summary A Soils B Soils C Soils D Soils Total % of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 0.00 0.00 0.00 0 Impervious Cover (acres) 0.00 0.00 0.00 0.00 0.00 0 0.00 BMP Selections Managed Turf Impervious Cover BMP Treatment TP Load from Practice Credit Area Credit Area I s Volume (ft) Upstream Untreated TP Load to Practice (Ibs) TP Removed (lb/yr) TP Remaining (lb/yr) Downstream Treatment to be Employed acres acres practices lb, Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (Ib/yr) 0.00 Total TN Load Reduction Achieved in D.A. 0.00 Ib/ r Runoff Volume and CN Calculations Summary Print Virginia Runoff Reduction Method Worksheet 1-yearstorm 2-yearstorm 10-yearstorm Target Rainfall Event (in) 1 0.00 0.00 0.00 Drainage Areas RV & CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN 0 0 0 0 0 RR (ft3) 0 0 0 0 0 1-year return period RV wo RR (ws-in) 0.00 0.00 0.00 0.00 0.00 RV w RR (ws-in) 0.00 0.00 0.00 0.00 0.00 CN adjusted 0 0 0 0 0 2-year return period RV wo RR (ws-in) 0.00 0.00 0.00 0.00 0.00 RV w RR (ws-in) 0.00 0.00 0.00 0.00 0.00 CN adjusted 0 0 0 0 0 10-year return period RV wo RR (ws-in) 0.00 0.00 0.00 0.00 0.00 RV w RR (ws-in) 0.00 0.00 0.00 0.00 0.00 CN adjusted 0 0 0 0 0 Summary Print PRE ONSITE 3S -I> POST AREA 1-D i S �a ANALYSIS PT 1 POST AREA 1-U -�2P Oz POST AREA 1-D SWM A � FUT FUTURE ANALYSIS PT 1 (4S POST AREA 1-U (FUTURE) Subcat Reach on Link AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (selected nodes) Area CN Description (acres) (subcatchment-numbers) 0.460 84 50-75% Grass cover, Fair, HSG D (1S) 0.870 80 >75% Grass cover, Good, HSG D (2S, 3S, 4S, 5S) 2.660 98 Paved parking, HSG D (1 S, 2S, 3S, 4S, 5S) 3.990 92 TOTAL AREA AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (selected nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 3.990 HSG D 1 S, 2S, 3S, 4S, 5S 0.000 Other 3.990 TOTAL AREA AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 4 Ground Covers (selected nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.000 0.000 0.460 0.000 0.460 50-75% Grass cover, Fair 1 S 0.000 0.000 0.000 0.870 0.000 0.870 >75% Grass cover, Good 2S, 3S, 4S, 5S 0.000 0.000 0.000 2.660 0.000 2.660 Paved parking 1 S, 2S, 3S, 4S, 5S 0.000 0.000 0.000 3.990 0.000 3.990 TOTAL AREA AutoZone SWM Analysis Pre & Post Type 1124-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 5 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41% Impervious Runoff Depth=2.28" Tc=6.0 min CN=93 Runoff=4.94 cfs 0.253 of Subcatchment2S: POSTAREA1-1.11 Runoff Area=0.400 ac 17.50% Impervious Runoff Depth=1.47" Tc=6.0 min CN=83 Runoff=1.01 cfs 0.049 of Subcatchment3S: POST AREA 1-D Runoff Area=0.930 ac 83.87% Impervious Runoff Depth=2.48" Tc=6.0 min CN=95 Runoff=3.65 cfs 0.192 of Subcatchment4S: POSTAREA1-1.11 Runoff Area=0.370 ac 18.92% Impervious Runoff Depth=1.47" Tc=6.0 min CN=83 Runoff=0.94 cfs 0.045 of Subcatchment5S: POST AREA 1-D Runoff Area=0.960 ac 90.63% Impervious Runoff Depth=2.58" Tc=6.0 min CN=96 Runoff=3.86 cfs 0.207 of Pond 1 P: SWM A Peak Elev=454.78' Storage=0.017 of Inflow=3.65 cfs 0.192 of Outflow=2.70 cfs 0.192 of Pond 2P: SWM A Peak Elev=454.98' Storage=0.019 of Inflow=3.86 cfs 0.207 of Outflow=2.81 cfs 0.207 of Link 1: ANALYSISPT 1 Inflow=3.62 cfs 0.241 of Primary=3.62 cfs 0.241 of Link FUT: ANALYSISPT 1 Inflow=3.66 cfs 0.252 of Primary=3.66 cfs 0.252 of Total Runoff Area = 3.990 ac Runoff Volume = 0.746 of Average Runoff Depth = 2.24" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1S: PRE ONSITE Runoff = 4.94 cfs @ 11.96 hrs, Volume= 0.253 af, Depth= 2.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE 3 0 LL 2 1 Hydrograph I I I I I I I I I I I Type II 24+hr k ailnfall'=.q3'` RLJnbff Area=1.330 lab I I I I I I I I I I I I I I I I I Runoff) Vlo1umne=;0.2531 of 1 1 ku�ngq oejph-�.�8'�' Tl:=IIII:61.01 nlih ^N=193 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 1.01 cfs @ 11.97 hrs, Volume= 0.049 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-U Hydrograph ❑ Runoff Type II 24+hr kainfall �.013'6 RLJnbff Area=0.400 ac 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Flu noff 1 V1ol1u mne�0.0491 of 1 1 1 kunpo Oejlp�hr111.47" 1 1 1 1 1 1 1 1 1 1 1 Tt=l:&01 Min 1 1 1 1 1 1 1 1 /IN 1+ A 1' 1 1 VA='83 I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 3.65 cfs @ 11.96 hrs, Volume= 0.192 af, Depth= 2.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D Hydrograph 4 3.6 cfs Type II 24+hr - I- I- t t t —1 -yR Rainfall 03�t 3 1 1 1 1 1 1 114 1 1 1 1 1 Rdnbff Area=0.93101ab 1 11 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I I I I 1 1 1 1 Runoff) V1o11umne=;0.11921 of Ai �1nQff O�iN#-�� 1 I,, 0 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Tt:�&01 Min u 1 1 1 1 1 1 1 � I+ I' I C I A ='9 J I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) � Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 0.94 cfs @ 11.97 hrs, Volume= 0.045 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) Hydrograph ❑ Runoff 1 0.94 cfs Type II 24+hr kainfall �.0;3'6 14 RLJnbff Area=0.370 ac i i i i Runoff Voliullme=;0.045 of kunpo Oejlp�hr1',.47;' ° 1 1 1 1 1 1 1 Tt=l:&01 Min LL CN=-83 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 3.86 cfs @ 11.96 hrs, Volume= 0.207 af, Depth= 2.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) Hydrograph 4 1 1 1 1 1 1 1 1 1 1 1 3.8s cfs I I I I I I I I I I I I I I I 1 1 I I 1 1 Type II 24+hr �- kainfalll .0'3'16 ------------ -------------------- 3 1 1 1 1 1 1 1 1 Rdnbff Arrec-1=0.960'ae. .11 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Runoff) V1o11umne=;0.2071 of tunQ Oep�hr�.58ry 0 2 1 1 1 1 1 Tt:�&01 Min LL 1 1 1 1 1 1 1 1 1 1 1 1 1 ^A 11' 1 1 =96 I I I I I I I I I I I I I I I 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 11 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 2.48" for 1-YR event Inflow = 3.65 cfs @ 11.96 hrs, Volume= 0.192 of Outflow = 2.70 cfs @ 12.03 hrs, Volume= 0.192 af, Atten= 26%, Lag= 3.9 min Primary = 2.70 cfs @ 12.03 hrs, Volume= 0.192 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 454.78' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.017 of Plug -Flow detention time=1.6 min calculated for 0.192 of (100% of inflow) Center -of -Mass det. time= 1.6 min ( 781.0 - 779.3 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=2.66 cfs @ 12.03 hrs HW=454.72' (Free Discharge) t-rCulvert (Passes 2.66 cfs of 6.59 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.66 cfs @ 7.26 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 12 Pond 1 P: SWM A Hydrograph I I I I I I I I I I I I I I I I I °fs Inflow iArea=0.930 as I�-�-a1k ev��4 48y- �torage=01.dl at I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 13 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 2.58" for 1-YR event Inflow = 3.86 cfs @ 11.96 hrs, Volume= 0.207 of Outflow = 2.81 cfs @ 12.03 hrs, Volume= 0.207 af, Atten= 27%, Lag= 4.0 min Primary = 2.81 cfs @ 12.03 hrs, Volume= 0.207 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 454.98' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.019 of Plug -Flow detention time=1.7 min calculated for 0.206 of (100% of inflow) Center -of -Mass det. time= 1.7 min ( 773.9 - 772.1 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=2.78 cfs @ 12.03 hrs HW=454.92' (Free Discharge) t-rCulvert (Passes 2.78 cfs of 6.91 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.78 cfs @ 7.58 fps) 3=Orifice/Grate ( Controls 0.00 cfs) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 14 Pond 2P: SWM A Hydrograph ■ Inflow 3.86 CTS 0 Primary 4 1 I I I I I I I I I I I I Inflow lArea=0.�960�as I 1 1 1 1 1 I I I I 1 1 1 I I I I OE1 alk 11 Ellev-"4�41.9�8y ----------- ------------------- 1 1 1 1 1 1 1 1 1 1 3 z.a,crs 1 1 1 toi ag@-0.019 a N T T 7�� I I I I 7� I I I I I F T T 7� I I I 0 2 / I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 1124-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 15 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91% Impervious, Inflow Depth = 2.18" for 1-YR event Inflow = 3.62 cfs @ 12.00 hrs, Volume= 0.241 of Primary = 3.62 cfs @ 12.00 hrs, Volume= 0.241 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs N V 3 0 LL Link 1: ANALYSIS PT 1 Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 16 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 2.27" for 1-YR event Inflow = 3.66 cfs @ 12.00 hrs, Volume= 0.252 of Primary = 3.66 cfs @ 12.00 hrs, Volume= 0.252 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs N U 3 0 LL Link FUT: ANALYSIS PT 1 Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 1124-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 17 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41% Impervious Runoff Depth=2.89" Tc=6.0 min CN=93 Runoff=6.17 cfs 0.320 of Subcatchment2S: POSTAREA1-1.11 Runoff Area=0.400 ac 17.50% Impervious Runoff Depth=1.99" Tc=6.0 min CN=83 Runoff=1.37 cfs 0.066 of Subcatchment3S: POST AREA 1-D Runoff Area=0.930 ac 83.87% Impervious Runoff Depth=3.10" Tc=6.0 min CN=95 Runoff=4.50 cfs 0.240 of Subcatchment4S: POSTAREA1-1.11 Runoff Area=0.370 ac 18.92% Impervious Runoff Depth=1.99" Tc=6.0 min CN=83 Runoff=1.26 cfs 0.061 of Subcatchment5S: POST AREA 1-D Runoff Area=0.960 ac 90.63% Impervious Runoff Depth=3.20" Tc=6.0 min CN=96 Runoff=4.72 cfs 0.256 of Pond 1 P: SWM A Peak Elev=455.53' Storage=0.024 of Inflow=4.50 cfs 0.240 of Outflow=3.40 cfs 0.240 of Pond 2P: SWM A Peak Elev=455.62' Storage=0.024 of Inflow=4.72 cfs 0.256 of Outflow=3.81 cfs 0.256 of Link 1: ANALYSISPT 1 Inflow=4.52 cfs 0.306 of Primary=4.52 cfs 0.306 of Link FUT: ANALYSISPT 1 Inflow=4.97 cfs 0.318 of Primary=4.97 cfs 0.318 of Total Runoff Area = 3.990 ac Runoff Volume = 0.944 of Average Runoff Depth = 2.84" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 1S: PRE ONSITE Runoff = 6.17 cfs @ 11.96 hrs, Volume= 0.320 af, Depth= 2.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE Hydrograph I I I I I I I I Type II 24+hr �-Yo Rainfall1=�.06" RLJnbff Area=1.3310'ab I I I I I I I I`, I I I I I I - I— I— -Runoff Volume=* A2n -af 1 1 I Runpo Oejlp�h-�.09'�' I TTT 1 1 I TTT`t�:61.01rWhi 1 1 1 1 1 1 1 1 1 1 1 1 1 11' 1 1 ^A I I I I I I I I I I I I 1 =193 ;1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 1.37 cfs @ 11.97 hrs, Volume= 0.066 af, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-U Hydrograph I I I I 1 1 11.3 cfs 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Type II 24+hr 1 1 1 } -Yk bainfall' �.06'16 i l l l l l l l l l l I I I I I I I — Rtinbff Area=0.4001aid 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Runoff) V1o11umne=;0.0661 of kungq Oejlp�h-l1.09r� o 1 1 1 1 1 1 1 Tt:�&01 Min LL 1 1 1 1 1 1 1 1 1 1 1 1 1 VA/IN 1+ A 1' 1 1 ='83 I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 4.50 cfs @ 11.96 hrs, Volume= 0.240 af, Depth= 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Type II 24+hr r ? 1 �-`�F tainfall - �.06'1 I I Rdnbff Area=0.9310 lab 1 1 1 1 1 1 1 1 1 1 1 1 i i T RuinofflVo1-ume=;0:Z4-Olaf kunpo Oejp�h-$.I '' Till:*644THrt I I I I I I I I I I I I I I I I I ^N =195 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 1.26 cfs @ 11.97 hrs, Volume= 0.061 af, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) Hydrograph I I I I 1 1 11.2 cfs 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Type II 24+hr } -Yk bainfall' �.06'6 1 1 1 1 RLJnbff Arrec-1=0.3701ae. I I I I I I I I I I I I I I I I I 1 1 1 1 Runoff1 V1o11umne=;0.0611 of kunpo Oejlp�hr111•09r� o 1 1 1 1 1 1 1 Tt:�&01 Min LL 1 1 1 1 1 1 1 1 1 1 1 1 1 VA/IN 1+ A 1' 1 1 ='83 I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 4.72 cfs @ 11.96 hrs, Volume= 0.256 af, Depth= 3.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) Hydrograph I I I I I I I I rt rt -I -I I- 1- 7--r rt -I - I - I- I- 7- rt rt-1 - I - I - I- t- 5 4.7z cfs Type II 24+hr 4 -� -1-1- -1 i-*kwnfaI10.06'I' 1 1 1 1 1 1 RLJnbff Area=0.9601ab I I I I I I I I I I I I I I I I I I I I I I I I I L 1-1 -1 -1-1- L L 1-L 1_ L-Runoff lVolume:PO.Miaf Z. 3 I 1 1 1 I I 1 1 1 I 1 I I '1`ulnp `I'ejlp�h-$.�O'I' 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Tt:�&0' nlih u. �rt�IIIrfirtrt- 2 ^A=196 IIfirtrtIIIIfirtrt�11'1c� I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 3.10" for 2-YR event Inflow = 4.50 cfs @ 11.96 hrs, Volume= 0.240 of Outflow = 3.40 cfs @ 12.04 hrs, Volume= 0.240 af, Atten= 24%, Lag= 4.4 min Primary = 3.40 cfs @ 12.04 hrs, Volume= 0.240 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 455.53' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.024 of Plug -Flow detention time=1.9 min calculated for 0.240 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 775.4 - 773.5 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=3.32 cfs @ 12.04 hrs HW=455.46' (Free Discharge) t-rCulvert (Passes 3.32 cfs of 7.72 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.07 cfs @ 8.37 fps) 3=Orifice/Grate (Orifice Controls 0.25 cfs @ 1.09 fps) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 24 Pond 1 P: SWM A Hydrograph ■ Inflow ❑ Primary 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 25 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 3.20" for 2-YR event Inflow = 4.72 cfs @ 11.96 hrs, Volume= 0.256 of Outflow = 3.81 cfs @ 12.02 hrs, Volume= 0.256 af, Atten= 19%, Lag= 3.2 min Primary = 3.81 cfs @ 12.02 hrs, Volume= 0.256 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 455.62' @ 12.02 hrs Surf.Area= 0.009 ac Storage= 0.024 of Plug -Flow detention time=1.9 min calculated for 0.256 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 768.6 - 766.7 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=3.68 cfs @ 12.02 hrs HW=455.55' (Free Discharge) t-rCulvert (Passes 3.68 cfs of 7.84 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.11 cfs @ 8.49 fps) 3=Orifice/Grate (Orifice Controls 0.57 cfs @ 1.43 fps) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 26 Pond 2P: SWM A Hydrograph T T T T T T T T 7-T T T T 7-T-1 I ■ Inflow 5 I I I I I I I I I I I)If, ❑ Primary Inflow iArea=0.960 as lI -*eak 1 ev"4F 5�.621 4 3.8 storage=0.0241 a T T 7 T T 1 1 1 1 1 T T T - - - I in 3 I I I I I I I I I I I ( I I I I I I I I I I I I I I I I I I I I I I I I I I I I I c 1 1 1 1 1 1IIIII IIIII1 1II 2 l l l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 27 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91 % Impervious, Inflow Depth = 2.76" for 2-YR event Inflow = 4.52 cfs @ 12.01 hrs, Volume= 0.306 of Primary = 4.52 cfs @ 12.01 hrs, Volume= 0.306 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs N U 3 0 LL Link 1: ANALYSIS PT 1 Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 28 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 2.87" for 2-YR event Inflow = 4.97 cfs @ 12.00 hrs, Volume= 0.318 of Primary = 4.97 cfs @ 12.00 hrs, Volume= 0.318 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs N V 3 0 LL Link FUT: ANALYSIS PT 1 Hydrograph 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 1124-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 29 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41% Impervious Runoff Depth=4.72" Tc=6.0 min CN=93 Runoff=9.76 cfs 0.523 of Subcatchment2S: POST AREA 1-U Runoff Area=0.400 ac 17.50% Impervious Runoff Depth=3.66" Tc=6.0 min CN=83 Runoff=2.45 cfs 0.122 of Subcatchment3S: POST AREA 1-D Runoff Area=0.930 ac 83.87% Impervious Runoff Depth=4.94" Tc=6.0 min CN=95 Runoff=6.98 cfs 0.383 of Subcatchment4S: POST AREA 1-U Runoff Area=0.370 ac 18.92% Impervious Runoff Depth=3.66" Tc=6.0 min CN=83 Runoff=2.27 cfs 0.113 of Subcatchment5S: POST AREA 1-D Runoff Area=0.960 ac 90.63% Impervious Runoff Depth=5.06" Tc=6.0 min CN=96 Runoff=7.26 cfs 0.405 of Pond 1 P: SWM A Peak Elev=456.12' Storage=0.028 of Inflow=6.98 cfs 0.383 of Outflow=6.87 cfs 0.383 of Pond 2P: SWM A Peak Elev=456.19' Storage=0.029 of Inflow=7.26 cfs 0.405 of Outflow=7.15 cfs 0.405 of Link 1: ANALYSISPT 1 Inflow=9.52 cfs 0.505 of Primary=9.52 cfs 0.505 of Link FUT: ANALYSISPT 1 Inflow=9.60 cfs 0.518 of Primary=9.60 cfs 0.518 of Total Runoff Area = 3.990 ac Runoff Volume = 1.546 of Average Runoff Depth = 4.65" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 1S: PRE ONSITE Runoff = 9.76 cfs @ 11.96 hrs, Volume= 0.523 af, Depth= 4.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41 % Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE Hydrograph 10 I I I I I I I I I I I I i i i I I I I I I I I I I I I I III I I I I I I I I I I I I I CIS -976 TI ypIeI a1I 2I 4+I hrI 9 Ilk'fo Oainfollr.�3t -I 1 1 1 Runoff Area=1.330'aid T T-1 1 1 1 T T I F T T 1 1 I T T , 1 1 I— T T T 1 1 1 1 Runoff) Volume=;0.5231 of 6 F4nQo O�p�h-4.72" 0 5 1 1 1 1 1 1 1 Tc:�61.01 Min LL - 1— 4- 4 —1 —1 —1— k- -4 —1 —1 — II—-- 4 4 1 1 1 I I I 1 1 I I 1 1 1 CN=193 T-1-1-1-1—r-7 r- Trt—I—I— I — rr- TI—I—I — I —r- TT 3 I I I I I I I I I I I I I I I I I I I I I 2 I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 31 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 2.45 cfs @ 11.97 hrs, Volume= 0.122 af, Depth= 3.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-U Hydrograph l l l 2.45 cfs {IType II 24+hr — — — —I— II— — — — -4 —II 1 1 � + 4 10-�' � P kainfall 1=03'.� 2 RtJnbff Area=0.400 ac I I I I I I I I I I I I I I I I I I I I I I Runoffs Vlollumne=;0.11221 of w 1 1 I I kunpo Oejlp�h-$.66rV o I 1 1 I I I 1 Tt:�&01 Min LL 1 W N=183 l i i i l l i i i l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 6.98 cfs @ 11.96 hrs, Volume= 0.383 af, Depth= 4.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D I I I I I I I I I I T T J 1 1 1 L T T 7C 7 I I I I I I I I I I I L 1 J _I _1_1_ L L 1 L 6 I I I I I I I I I I — I TTJ 1 1 1 LTTT 5 I I I I I I I I I I w L1JJ11LL1L_ 4 o U. TTJ 1 1 1 LTT-1 3 1 i i i 1 1 i i i 2 z I I 1 1 I I I I Hydrograph I I I I I I I I I I I i I I T 7 J F Type II 24+hr RLJnbff Area=0.9310'ab I T T T 1 1I— F T II L I I I I Runoff 1V1o11uIIme=;0.383i of L 1 ungf(0epp hr��4"- I I I I I I I Tt=l:&01 nlih I— F T T T T -T 7 ^1-1 CI W I I I I I I I I I I I I N=195 1. 1 1 1 _I _1_I_ I_ L 1 J J _1_I_ I_ L I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 2.27 cfs @ 11.97 hrs, Volume= 0.113 af, Depth= 3.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) Hydrograph ■ Runoff i l l l l l l l l l l 1 Type II 24+hr t- t -t RLJnbff Area=0.370 lab I I I I I I I I I I I I I I Runoff l Vlollu mne=l 131 of 1 1 1 1tunQq 0e1p�h-$.66" 1 -rt# & 0 I rffl n_ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 " ' CN='83 I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 7.26 cfs @ 11.96 hrs, Volume= 0.405 af, Depth= 5.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) 8 C ——— 7 1 1 1 I 1 I I I I I I I fi rt-1 1 1 1 L t- rt I I 6 I I I I I I I I I I L1-1 I 1 1 LL1-1 5 I I I I I I I I I I I w I I I I I I I I I I I I 4 u + I L t-+ 4 3 2 I I I I I I I I I I I I I I I I r F T -T 1 I I I I I Hydrograph I I I I I I I I I I I I I I I I I 1 1 1 1 1 1 1 I TypeYI-24+fir 1'I` a i pfa �7�,a- I I t- rt -tI 1 1 1 1 1 RLJnbff Area=0.9601aid I I L 1 1-1 1 I L 1 A -1 —1 I L L 1 1 Runoff1V1o11umne=;0.4051of I I I I I I I I I I Tt=l:&01 niih 1 1 1 1 1 1 1 1 1 1 1 1 CN=196 t- T 7 1 1 I 7 T-t-1 I I L L I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff AutoZone SWM Analysis Pre & Post Type 1124-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 35 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 4.94" for 10-YR event Inflow = 6.98 cfs @ 11.96 hrs, Volume= 0.383 of Outflow = 6.87 cfs @ 11.98 hrs, Volume= 0.383 af, Atten= 1 %, Lag= 0.9 min Primary = 6.87 cfs @ 11.98 hrs, Volume= 0.383 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 456.12' @ 11.98 hrs Surf.Area= 0.008 ac Storage= 0.028 of Plug -Flow detention time=1.9 min calculated for 0.383 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 763.8 - 762.0 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=6.66 cfs @ 11.98 hrs HW=456.08' (Free Discharge) t-rCulvert (Passes 6.66 cfs of 8.54 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.37 cfs @ 9.18 fps) 3=Orifice/Grate (Orifice Controls 3.29 cfs @ 3.29 fps) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 36 / i i i i I I I I I I I + Pond 1 P: SWM A Hydrograph 8 cfs Inflow iArea=0.930 as I� a1kiE+lev�4t6.1112y I ai age-rQ 0�, 1a I I I I I I I I I I I I I I I I I I I I I I I I -L-1-1 —1 —1-1— 1— L L L I I I I I I I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 1124-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 37 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 5.06" for 10-YR event Inflow = 7.26 cfs @ 11.96 hrs, Volume= 0.405 of Outflow = 7.15 cfs @ 11.98 hrs, Volume= 0.405 af, Atten= 2%, Lag= 0.9 min Primary = 7.15 cfs @ 11.98 hrs, Volume= 0.405 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 456.19' @ 11.98 hrs Surf.Area= 0.008 ac Storage= 0.029 of Plug -Flow detention time=1.9 min calculated for 0.404 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 758.1 - 756.2 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routinq Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=6.94 cfs @ 11.98 hrs HW=456.15' (Free Discharge) t-rCulvert (Passes 6.94 cfs of 8.63 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.40 cfs @ 9.27 fps) 3=Orifice/Grate (Orifice Controls 3.54 cfs @ 3.54 fps) 4=Sharp-Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 38 r r r r r I I I I r 8 III I� / 7.15 7 / I I I I I I I I I I I 6 -+t-111I 5 N L J 1 L J _1 _1 _ 1_ 1_ L 3 4 c a / 3 1 1 1 1 1 1 I- T rt -T -1 —1 —1 — 1— 1- ' 2 I I I I I I I I I I + 4 -4 -4 1 Pond 2P: SWM A Hydrograph I I I I I I I I I I I I I I I I I i cfs - flovnr Ar-a=O:g6-0-a 11111 Peak av=4�61.11119y- 115#ortaige=4.0i2�11at 1 1 1 1 1 1 1 1 1 1 1 �IIIIIII _-- L L—rIIIII J 1—rtIIIII -1 J—�IIIII _--IIIIIII -1-1- 1_1_IIIIII _ II + II I- - I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Inflow ❑ Primary AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 39 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91 % Impervious, Inflow Depth = 4.56" for 10-YR event Inflow = 9.52 cfs @ 11.97 hrs, Volume= 0.505 of Primary = 9.52 cfs @ 11.97 hrs, Volume= 0.505 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link 1: ANALYSIS PT 1 Hydrograph tttt I I I I I 1-tttt I I I I tttt I I I I tt ■Inflow ' I I I I I I I 1 1 I I I I I I I I I I I ❑ Primary 9.52 cfsI 10 1-1-1-1— 1— i 952cis 1-Inflow-Area=11-.13Wac - g 8- 7 1-tfit-1-1-1-1— 1 t-1-1-1-1—rttt—1-1-1-1—�� 6 F 1 1 1 c 5 ————I_I———I—I-1 I I I I —— — —I—I—I U. i 3 t- t fi t 1 1 1 I 1 t t 1 —1—1— 1 r t t t -1 —1 1 I I t t- ' I I I I I I I I I I I I I I I I I I I I I I I I I I 2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCADO 10.00-20 s/n 06538 © 2017 HydroCAD Software Solutions LLC Page 40 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 4.67" for 10-YR event Inflow = 9.60 cfs @ 11.97 hrs, Volume= 0.518 of Primary = 9.60 cfs @ 11.97 hrs, Volume= 0.518 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link FUT: ANALYSIS PT 1 Hydrograph FillInflow LT1-4 1 1 1 1 1 L-kT4-4 1 1 I I LLT4A 1 1 I I k-L I I I I I I I I 1 1 9.60 cfs I I I I I I I I I I I I I I I ❑ Primary 10 T T T T 1 1 1 I I sso�t5 -r-i 1 /�I_� nfiowT/'"'\1 ea=10U.I��Cac- / 9 g LLLL 1 1 1 1 1 -1 1 -1-1- 1 L1T1L 1 1 1 1 LL i I I I I I I I I I I I I I I I I I I I I I I I I I I 7 L T 1-4 1 1 1 1 1 4 1 -1-1- 1 L L T 41 1 1 1 � L u 6 T T T T 1 1 1 1 T T T T T T T T / 5 _0 U. 4 L 1 1 L 1 111 1 L L 1 11 1 L L 1 1 L 1 111 L L 3 L t -t-t1 1 1 1 1- 1 -1-1- 1 L L t -t-11 1 1 1- 2 1 , 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) "Tomorrow's Natural Resources Today" COROHM11 Chesapeake Bay Nutrient LandTrust, LLC. November 8, 2019 Timmons Group ATTN: Anna Fontaine 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 RE: CBNLT / Oak Grove — Nutrient Credit Availability Project Reference: Autozone — Charlottesville Store #6464, Albemarle County Attention: Ms. Fontaine: This letter is to confirm the availability of authorized Nutrient Credits sufficient to meet your project requirements at our Oak Grove nutrient facility, which is registered with the Virginia Department of Environmental Quality (DEQ). These Nutrient Credits are generated and managed under the terms of the Oak Grove Nutrient Reduction Implementation Plan dated May 11, 2017 which was authorized by the DEQ on August 31, 2017. The Oak Grove project has been authorized to provide Nutrient Credits for use in the James River watershed. These Credits are transferable to those entities regulated under DEQ's Stormwater Management Program in accordance with VA Code § 62.1-44.15:35. Currently our Oak Grove facility has 8.80 pounds of Phosphorus Credits available. If we can provide further assistance please feel free to contact our office. Sincerely, Chesapeake Bay Nutrient Land Trust, LLC By Its Manager EarthSource Solutions, Inc. Scott -A. 12ee,cL Scott A. Reed Vice President Chesapeake Bay Nutrient Land Trust, LLC. • 5735 S. Laburnum Avenue • Richmond, VA 23231 • P: 804.222.5114 • www.cbnit.com