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HomeMy WebLinkAboutSDP202200009 Calculations 2022-05-08Rio Point COUNTY OF ALBEMARLE, VIRGINIA VSMP wPo-2022-00011 DESIGN CALCULATIONS & NARRATIVE FEBRUARY 7, 2022 REVISED MAY 69 2022 •�0000 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 U CRAIG W. J. KOTARSKI Lic. No. 0402048507 05/06/22 Table of Contents Section Title Project Narrative 2 Pipe and Inlet Computations Virginia Runoff Reduction Method Worksheet Summary 4 Pre -Developed HydroCAD Calculations Post -Developed HydroCAD Calculations 6 Nutrient Credit Availability Letter Project Narrative: This project includes the construction of 11 apartment buildings, 11 townhouses, a club house and other amenities, and all the associated parking and utilities for the development. Other improvements include roadway improvements to serve the development. Also included in the stormwater analysis for this project is the adjacent property Rio Commons that is currently under review. The adjacent property currently drains onsite and in future conditions, it is assumed it will drain to the onsite pond. Additional water quality storage was not provided for Rio Commons but the post development conditions were routed to meet channel and flood protection requirements. Water Quality Compliance: The disturbed area of 18.46 acres was used for the water quality analysis. In the proposed condition there will be 8.35 acres of managed turf, and 10.12 acres of impervious cover. The required phosphorus removal is 17.90 lb/yr. Approximately 13.87 lb/yr of phosphorus shall be removed through the installation of level 2 bioretentions, a and a level 1 wet pond. The remaining 4.03 lb/yr will be purchased from an offsite nutrient credit bank. Onsite phosphorus removal treatment will account for over 75% of the required phosphorus removal required. Water Quantity Compliance: The 1 % analysis point for this project is located just south west of the property in Meadow Creek. The site drainage currently leaves the site in three directions, north to the storm network in John W. Warner Parkway, southwest to sheet flow to Meadow Creek, and south to a defined channel that outfalls to Meadow Creek. All onsite drainage areas ultimately drain to Meadow Creek at the Analysis Point. The total drainage area at the Analysis Point is 2,963 acres. The total onsite drainage area is 18.46 acres. At the Analysis Point the onsite drainage area is 0.6% of the total drainage area. Runoff was analyzed at Outfalls 1 and 2 for compliance with energy balance for channel protection and detaining the 10-yr post developed peak flow rate below the 10-yr pre developed peak flow rate. Bioretention basins with additional storage capacity and a level 1 wet pond with additional storage capacity were utilized to meet the Stormwater Quantity requirements at each outfall. STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 10 PROJECT: Rio Point Designed by: J. Denko LOCATION: COUNTY: Albemarle Checked by: C. Kotarski UNITS ENGLISH PIPE NO FROM POINT TO POINT DRAIN. AREA "A" Acre (3) RUNOFF COEFF. "C" (4) CA TOTAL INLET TIME Minutes (7) RAIN FALL In/Hr (8) RUNOFF Q CFS (9) INVERT ELEVATIONS LENGTH of Pipe Ft. (12) SLOPE Ft./Ft. (13) SIZE (Dia. Or Span/Rise) In. (14) SHAPE Capacity CFS (15) Friction Slope Ft./Ft. VEL Vn Ft/Sec (16) FLOW TIME Min. (17) REMARKS (18) INCRE- MENT (5) ACCUM- ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. 103 104 102 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 413.000 410.736 45.103 0.050 6.000 Circular 1.361 0.000 0.000 0.000 101 102 100 0.000 0.000 0.000 2.267 2.267 0.000 8.901 20.176 410.736 409.529 128.694 0.009 48.000 Circular 139.081 0.000 7.899 0.272 239 240 238 0.220 0.800 0.176 0.176 0.000 6.000 6.230 1.096 464.169 460.614 177.078 0.020 15.000 Circular 9.913 0.000 5.331 0.554 237 238 236 0.440 0.770 0.339 0.572 0.057 6.554 6.072 3.472 460.510 455.860 172.955 0.027 15.000 Circular 11.471 0.002 8.209 0.351 235 236 234 0.420 0.730 0.307 1.211 0.333 6.905 5.976 7.236 455.760 455.030 73.095 0.010 18.000 Circular 11.370 0.004 6.833 0.178 233 234 232 0.420 0.770 0.323 1.639 0.105 7.083 5.929 9.716 454.930 452.955 200.497 0.010 24.000 Circular 24.321 0.002 7.323 0.456 231 232 230 0.190 0.380 0.072 1.816 0.105 6.400 6.115 11.101 452.860 450.880 75.538 0.026 24.000 Circular 39.673 0.002 10.852 0.116 229 230 228 0.490 0.700 0.343 2.263 0.105 6.516 6.082 13.764 450.781 450.000 78.068 0.010 24.000 Circular 24.505 0.003 8.043 0.162 227 228 226 0.200 0.870 0.174 2.437 0.000 6.678 6.037 14.713 449.900 447.500 92.375 0.026 30.000 Circular 71.620 0.001 11.501 0.134 245a 246a 244 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 459.687 458.750 94.099 0.010 15.000 Circular 6.980 0.000 0.000 0.000 243 244 242 0.270 0.480 0.130 0.130 0.000 6.000 6.230 0.807 458.650 457.774 58.446 0.015 15.000 Circular 8.564 0.000 4.395 0.222 241 242 226 0.300 0.430 0.129 0.316 0.057 6.222 6.166 1.946 457.670 456.080 73.507 0.022 15.000 Circular 10.288 0.001 6.457 0.190 225 226 224 0.180 0.900 0.162 2.915 0.000 6.812 6.001 17.491 447.069 435.543 72.030 0.160 30.000 Circular 177.732 0.002 23.089 0.052 275 284 282 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 460.500 460.055 89.069 0.005 15.000 Circular 4.947 0.000 0.000 0.000 273 282 270 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 459.950 458.989 192.278 0.005 15.000 Circular 4.947 0.000 0.000 0.000 271 270 260 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 458.890 458.773 23.334 0.005 15.000 Circular 4.947 0.000 0.000 0.000 259 260 258 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 458.670 457.986 136.760 0.005 15.000 Circular 4.947 0.000 0.000 0.000 257 258 256 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 457.890 456.760 154.416 0.007 15.000 Circular 5.985 0.000 0.000 0.000 267 268 256 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 458.299 457.570 145.671 0.005 15.000 Circular 4.947 0.000 0.000 0.000 255 256 254 0.000 0.000 0.000 1.176 1.176 6.000 6.230 7.327 453.969 453.456 102.325 0.005 18.000 Circular 8.045 0.004 5.173 0.330 253 254 252 0.000 0.000 0.000 1.176 0.000 6.330 6.135 7.215 453.360 451.480 47.983 0.039 18.000 Circular 22.520 0.004 11.365 0.070 265 266 264 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 458.020 457.517 100.461 0.005 15.000 Circular 4.947 0.000 0.000 0.000 263 264 262 0.000 0.000 0.000 0.240 0.240 6.000 6.230 1.497 457.420 451.930 90.367 0.061 15.000 Circular 17.245 0.000 8.640 0.174 261 262 252 0.240 0.740 0.178 0.418 0.000 6.174 6.179 2.583 451.830 451.478 70.392 0.005 15.000 Circular 4.947 0.001 4.084 0.287 251 252 224 0.000 0.000 0.000 1.784 0.190 6.462 6.097 10.878 451.380 434.700 114.233 0.146 18.000 Circular 43.475 0.009 20.498 0.093 223 224 202 0.000 0.000 0.000 4.699 0.000 6.864 5.987 28.131 425.462 418.421 44.005 0.160 36.000 Circular 289.029 0.002 25.989 0.028 219 220 218 0.330 0.760 0.251 0.365 0.114 6.000 6.230 2.273 463.627 460.700 203.448 0.014 15.000 Circular 8.392 0.001 5.824 0.582 217 218 216 0.510 0.760 0.388 0.866 0.114 6.582 6.064 5.254 460.600 456.700 191.781 0.020 15.000 Circular 9.977 0.006 8.253 0.387 215 216 214 0.250 0.840 0.210 1.076 0.000 6.969 5.959 6.414 456.600 456.025 25.456 0.023 15.000 Circular 10.512 0.008 9.009 0.047 213 214 212 0.380 0.790 0.300 1.377 0.000 7.017 5.946 8.186 455.517 453.859 234.116 0.007 18.000 Circular 9.574 0.005 6.102 0.639 211 212 210 0.080 0.820 0.066 1.556 0.114 7.656 5.783 8.999 453.760 452.443 131.675 0.010 18.000 Circular 11.377 0.006 7.155 0.307 209 210 208 0.360 0.650 0.234 1.904 0.114 7.963 5.708 10.869 452.340 451.172 116.823 0.010 24.000 Circular 24.505 0.002 7.582 0.257 207 208 206 0.290 0.780 0.226 2.130 0.000 8.219 5.647 12.030 451.070 450.597 47.255 0.010 24.000 Circular 24.505 0.002 7.781 0.101 221 222 206 0.110 0.790 0.087 0.087 0.000 0.000 8.901 0.773 454.004 453.004 53.253 0.019 15.000 Circular 9.587 0.000 4.701 0.189 205 206 204 0.000 0.000 0.000 2.217 0.000 8.321 5.623 12.468 440.895 433.000 49.346 0.160 24.000 Circular 98.018 0.003 21.441 0.038 249 250 248 0.000 0.000 0.000 0.337 0.337 6.000 6.230 2.101 440.920 440.293 125.318 0.005 15.000 Circular 4.947 0.001 3.875 0.539 247 248 204 0.000 0.000 0.000 0.337 0.000 6.539 6.076 2.049 440.190 432.100 142.530 0.057 15.000 Circular 16.668 0.001 9.243 0.257 203 204 202 0.780 0.370 0.289 2.843 0.000 8.359 5.614 15.963 427.857 416.692 381.238 0.029 30.000 Circular 76.040 0.001 12.286 0.517 201 202 200 0.000 0.000 0.000 7.542 0.000 8.876 5.498 41.462 415.000 413.596 51.623 0.027 36.000 Circular 119.153 0.003 15.370 0.056 305 306 304 0.280 0.330 0.092 0.092 0.000 0.000 8.901 0.822 448.032 445.807 44.484 0.050 12.000 Circular 8.627 0.000 6.942 0.107 303 304 302 0.450 0.870 0.392 0.484 0.000 0.107 8.829 4.273 443.650 431.503 75.918 0.160 15.000 Circular 27.985 0.004 16.520 0.077 301 302 300 0.370 0.310 0.115 0.599 0.000 0.183 8.779 5.255 424.018 413.000 91.817 0.120 15.000 Circular 24.235 0.006 15.809 0.097 701 1 702 1 10+28.66 1 700 1 10+00.00 1 0.000 1 0.000 1 0.000 1 0.116 1 0.116 1 0.000 1 8.901 1 1.032 1 440.670 1 439.500 1 28.663 1 0.041 1 15.000 1 Circular 1 14.135 1 0.000 1 6.728 1 0.071 805 806 804 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 455.873 450.000 118.010 0.050 15.000 Circular 15.607 0.000 0.000 0.000 803 804 802 0.000 0.000 0.000 0.000 0.000 0.000 8.901 0.000 449.548 447.575 90.444 0.022 15.000 Circular 10.333 0.000 0.000 0.000 809 810 808 0.280 0.900 0.252 0.252 0.000 0.000 8.901 2.243 449.000 447.360 41.463 0.040 15.000 Circular 13.914 0.001 8.343 0.083 807 808 802 0.000 0.000 0.000 0.252 0.000 0.083 8.845 2.229 447.257 446.190 213.280 0.005 15.000 Circular 4.947 0.001 3.935 0.903 801 802 800 0.430 0.840 0.361 0.832 0.219 0.986 8.286 6.892 446.090 445.500 24.191 0.024 18.000 Circular 17.768 0.004 9.438 0.043 HYDRAULIC GRADE LINE ANALYSIS CEel lrl:1!161ZISM9-314Ywil 10 Year DESIGNED BY: J. Denko Checked: C. Kotarski INLET OR JUNCTION INLET STATION OUTLET WATER SURFACE ELEV. DIA. PIPE Do (In) DESIGN DISCH. Do (CFS) LENGTH PIPE Lo (Ft) FRICTION SLOPE, Sfo (FT/FT) FRICTION LOSS Hf (Ft) JUNCTION LOSS FINAL H (Ft) Inlet Water Surface Elevation Rim Elev Comments Vo Ho (Ft) Qi Vi QiVi Vi'2/2g Hi Angle HO Ht 1.3 Ht 0.5 Ht 102 414.2 48 20.18 128.69 0.02% 0.03 7.9 0.24 0 0 0 0 0 0 0 0.24 0 TRUE 0.15 414.35 422 OK -7.65 104 414.35 6 0 45.1 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 414.35 413.54 N/A: Pond Drain 202 422.52 36 41.46 51.62 0.33% 0.17 15.37 0.92 28.13 25.99 731.1 10.49 3.67 96.1 1.64 6.23 0 TRUE 3.28 425.8 429.8 OK -3.99 224 422.78 36 28.13 44 0.15% 0.07 25.99 2.62 17.49 23.09 403.84 8.28 2.9 63.1 4.64 10.15 0 TRUE 5.14 427.92 447.38 OK -19.46 226 437.54 30 17.49 72.03 0.15% 0.11 23.09 2.07 14.71 11.5 169.22 2.05 0.72 28.88 0.72 3.51 0 TRUE 1.87 439.41 462.56 OK -23.15 228 449.5 30 14.71 92.38 0.11% 0.1 11.5 0.51 13.76 8.04 110.71 1 0.35 70.32 0.61 1.48 0 TRUE 0.84 450.34 461 OK -10.66 230 451.6 24 13.76 78.07 0.32% 0.25 8.04 0.25 11.1 10.85 120.47 1.83 0.64 68.49 1.12 2.01 0 TRUE 1.25 452.85 460.5 OK -7.65 232 452.85 24 11.1 75.54 0.21% 0.15 10.85 0.46 9.72 7.32 71.15 0.83 0.29 91.83 0.58 1.33 0 TRUE 0.82 453.67 460.33 OK -6.66 234 454.56 24 9.72 200.5 0.16% 0.32 7.32 0.21 7.24 6.83 49.44 0.72 0.25 86.01 0.51 0.97 0 TRUE 0.8 455.35 462.38 OK -7.03 236 456.23 18 7.24 73.09 0.40% 0.3 6.83 0.18 3.47 8.21 28.5 1.05 0.37 3.99 0 0.55 0.71 TRUE 0.65 456.88 463.43 OK -6.54 238 456.88 1 15 1 3.47 1172.951 0.25% 1 0.43 1 8.21 1 0.26 1 1.1 1 5.33 1 5.85 1 0.44 1 0.15 1 22.51 1 0.13 1 0.55 1 0.71 1 TRUE 1 0.78 1 457.66 1 465.59 1 OK -7.93 240 1 461.61 1 15 1 1.1 1177.081 0.02% 1 0.04 1 5.33 1 0.11 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.11 1 0.14 1 TRUE 1 0.12 1 461.73 1 468.84 1 OK -7.11 204 425.8 30 15.96 381.24 0.13% 0.49 12.29 0.59 12.47 21.44 267.33 7.14 2.5 73.9 4.35 7.44 0 TRUE 4.21 430.02 438.01 OK -8 206 434.6 24 12.47 49.35 0.26% 0.13 21.44 1.78 12.03 7.78 93.6 0.94 0.33 27.68 0.33 2.44 0 TRUE 1.35 435.95 458.47 OK -22.52 208 452.2 24 12.03 47.25 0.24% 0.11 7.78 0.24 10.87 7.58 82.41 0.89 0.31 41.2 0.38 0.93 0 TRUE 0.58 452.78 459.1 OK -6.33 210 452.78 24 10.87 116.82 0.20% 0.23 7.58 0.22 9 7.15 64.39 0.79 0.28 0 0 0.5 0 TRUE 0.48 453.26 460 OK -6.74 212 453.64 18 9 131.67 0.63% 0.82 7.15 0.2 8.19 6.1 49.95 0.58 0.2 0.96 0 0.4 0 TRUE 1.02 454.67 461.4 OK -6.73 214 455.06 18 8.19 234.12 0.52% 1.21 6.1 0.14 6.41 9.01 57.78 1.26 0.44 44.04 0.54 1.13 1.47 TRUE 1.94 457 460.51 OK -3.5 216 457.03 15 6.41 25 6 0.84% 0.21 9.01 0.32 5.25 8.25 43.36 1.06 0.37 45 0.53 1.21 0 TRUE 0.82 457.85 460.96 OK -3.11 218 457.85 15 5.25 191.78 0.56% 1.08 8.25 0.26 2.27 5.82 13.24 0.53 0.18 0 0 0.45 0.58 TRUE 1.37 459.22 464.98 OK -5.76 220 461.7 1 15 1 2.27 1203.451 0.11% 1 0.21 1 5.82 1 0.13 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.13 1 0.17 1 TRUE 1 0.3 1 462 1 467.97 1 OK -5.97 248 433.1 1 15 1 2.05 1142.53 1 0.09% 1 0.12 1 9.24 1 0.33 1 2.1 1 3.88 1 8.14 1 0.23 1 0.08 1 54.82 1 0.12 1 0.53 1 0 1 TRUE 1 0.39 1 433.49 1 446.25 1 OK -12.76 250 441.29 1 15 1 2.1 1125.32 1 0.09% 1 0.11 1 3.88 1 0.06 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.06 1 0 1 TRUE 1 0.14 1 441.44 1 445.25 1 OK -3.81 222 1 1 454 1 15 1 0.77 1 53.25 1 0.01% 1 0.01 1 4.7 1 0.09 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.09 1 0.11 1 TRUE 1 0.06 1 454.07 1 459.03 1 OK -4.97 252 435.9 18 10.88 114.23 0.91% 1.04 20.5 1.63 7.21 11.37 82 2.01 0.7 57.19 1.12 3.46 0 TRUE 2.77 438.67 461.73 OK -23.06 254 452.68 18 7.21 47.98 0.40% 0.19 11.37 0.5 7.33 5.17 37.9 0.42 0.15 35.4 0.18 0.83 0 TRUE 0.61 453.29 462.51 OK -9.22 256 461.26 18 7.33 102.32 0.41% 0.42 5.17 0.1 0 0 0 0 0 0 0 0.1 0 TRUE 0.48 461.74 464.26 OK -2.53 258 461.74 15 0 154.42 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 461.74 466.66 OK -4.93 260 461.74 15 0 136.76 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 461.74 465.12 OK -3.38 270 461.74 15 0 23.33 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 461.74 463.12 OK -1.38 282 461.74 15 0 192.28 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 461.74 465.26 OK -3.53 284 461.74 15 0 89.07 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 461.74 464.5 OK -2.77 262 452.48 15 2.58 70.39 0.14% 0.1 4.08 0.06 1.5 8.64 12.94 1.16 0.41 46.84 0.58 1.05 1.36 TRUE 0.78 453.26 459.74 OK -6.48 264 456.71 15 1.5 90.37 1 0.05% 0.04 1 8.64 0.29 0 0 0 0 0 0 0 0.29 0 TRUE 0.19 1 456.9 462.69 OK -5.79 266 458.52 1 15 1 0 1100.461 0.00% 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 TRUE 1 0 1 458.52 1 462.77 1 OK -4.25 268 1 1 458.57 1 15 1 0 1145.671 0.00% 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 TRUE 1 0 1 458.57 1 463.05 1 OK -4.48 242 457.08 15 1.95 73.51 0.08% 0.06 6.46 0.16 0.81 4.4 3.55 0.3 0.1 90.19 0.21 0.48 0.62 TRUE 0.37 457.45 462.73 OK -5.28 244 458.77 15 0.81 58.45 0.01% 0.01 4.4 0.07 0 0 0 0 0 0 0 0.07 0.1 TRUE 0.06 458.83 464.53 OK -5.7 246a 459.75 15 0 94.1 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 459.75 464.44 OK -4.69 302 422.52 15 5.25 91.82 0.56% 0.52 15.81 0.97 4.27 16.52 70.58 4.24 1.48 9.23 0.55 3 0 TRUE 2.02 424.54 436.34 OK -11.8 304 432.5 15 4.27 75.92 0.37% 0.28 16.52 1.06 0.82 6.94 5.71 0.75 0.26 23.79 0.22 1.55 2.01 TRUE 1.29 433.79 453.79 OK -20 306 446.61 12 0.82 44.48 0.05% 0.02 6.94 0.19 0 0 0 0 0 0 0 0.19 0.24 TRUE 0.14 446.75 452.5 OK -5.75 702 1 1 440.5 1 15 1 1.03 1 28.66 1 0.02% 1 0.01 1 6.73 1 0.18 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0.18 1 0 1 TRUE 1 0.09 1 440.59 1 445.5 1 OK -4.91 802 446.7 18 6.89 24.19 0.37% 0.09 9.44 0.35 2.23 3.93 8.77 0.24 0.08 90 0.17 0.6 0.78 TRUE 0.48 447.18 454.84 OK -7.66 804 448.57 15 0 90.44 1 0.00% 0 0 0 0 0 0 0 0 0 0 0 0 TRUE 0 448.57 457.29 OK -8.72 806 451 1 15 1 0 1118.011 0.00% 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 TRUE 1 0 1 451 1 463.61 1 OK -12.61 808 447.19 15 2.23 213.28 0.10% 0.22 3.93 0.06 2.24 8.34 18.71 1.08 0.38 43.44 0.46 0.9 0 TRUE 0.67 447.86 451.32 OK -3.46 810 448.36 15 2.24 41.46 0.10% 0.04 8.34 0.27 0 0 0 0 0 0 0 0.27 0.35 TRUE 0.22 448.58 453.12 OK -4.55 DFq WMinla mamff aaduama MCMOE Xew kvelopmm[ Cumplbnre SprevGheef [."ZOI1 WPSbtlatlaaM 3gtllkalbw 03013 Draft BMP s tandasds anal SpecMemlms Psofed Name : . 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Pnsrtl Dz3M Ttm4nem Volumel[5Ri[]MI GO$C3 TP bad Xb/Ytl ESAE m seatlllb/wl orRMI�Crrpwaw canwith-i ea all Drainage Area A Drainage Area A land Cnaer Anne) P Sails BSolls CSolls OSOIIs Totals lantl Cover Rv ra,art/opanswsaaexl oao o.Da Manaeetll,fi—) 2.30 4.5C 6.80 0.18 Imwrviwx[overlanreg 1.05 8.36 9.01 0.95 Total statistical Awl for Rental in l A (lb/Yr) 2325 Total 16.25 Post Deaelopmm en[ Treatent Volume in D.A. A iI 3]•NO 2. Rooftop Disconnection (l zasmPle Oxnnnxtinnb waso lx grac Ml so 0 0 0 0 0 n. o00 tre 000 E.h.SlmpI,Dlsnnn¢4nnm C/0solx ISpe,Ml ss 0 0 0 0 0 1. o00 t. ot0 z.. l ended Fuv P,dh- , ect,aranx hs gC/Dxolxllspa,M) w rtn So 0 D o 0 0 nm o00 t. oao zd. IDOrywellm Flenmo,il Mm,n-mmmhan 41(Sps M) 0 0 D 0 zs nm per, t. irm 1eTo Dry well or arn,n Da n xE m¢rnmoh Nzlspe,NRI co D 0 D 021 oM oao o.O] oao Bran u To RatGaraenill, wl lspe,wRl m o D o o zs DM oM o.M oM zg. Tn Fa^n Garden N2, sn—li et-tonpz ISPx MI 60 0 0 0 0 Se oM per, o.M oM z n. To irwater o escehng(St—cra 0 0 D o 0 0 oM oM o.M oM E.. To She,owater, Planter, U nonBrnaln(1,re, Appenaa A) Qo 0 0 0 0 Es oM oM oM oM 4. Grass Channel RR) O.a.Grazz Cwn-ll,oRsoilxl5px N3) Eo 0 0 0 oM oM oM is. Ob. Grass Clunmi C/O soils liw, Nil ]0 0 0 0 011 oM oM o.M oM <.r. Grass CM1anrel with Comport Aawere sails Spe.Ml p 0 0 0 0 oM oM o.M Innwrzp�lwe S., 0ry Si-Il lsperNNl 0 0 0 0 EO oM oM o.M oM s.n Dry swala xE lies NNl 0 0 0 o w oM oM o.M oM 6.a. R'mMmtion an or Mirm8'' notion At or Orenfear raionlSp¢NI Ao 0 0 0 Es oM oM tinoM 11a.wnl 0. O. Grass Channel (RR) S. Dry Swale )RR) 6. Blot etention (RR) N Nwa_CuM®i Dx,A Yrl_w_I'dIDl]-1 .. •••`•`•••••• ••••••� •`•`••• IsvKM91 BO 036 O6] 0 ZOF FO ] 1,031 50 0.0] 190 1]] 0.19 13a.we Puna xl ].a.IMlbatiun At (spe ! s0 0 0 ss 0.m oa 000 0.m zh, Irdifinam, w easm M) 90 0 0 ss 0.0] ot0 000 0.0] 8. Extended Detention Pond filifi R.a. On., erxlsl 0 0 D.m ow 0m D.m ae.[oxl Preen15 Ss o 0 0 0 15 0.00 oao 0. o.. TOTALIMIERNOUSCOVER TREATED(:[ 0.R1 AREA CHECK: OR. TOTAL MANAGED TURF A= TREATED (ac) 0.36 AREACHECK: OK. TOTAL RUNOFF REDURION IN DA A (H)l 2,626 TOTALPHOSPHORUSAVAIIABLE FOR REMOVALIN OAA(IbM 23.25 US DES ad, TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REON PRACNCES IINOA A(lbM 21'S3 D CT SEE WATER QUALITYCOMPLIANCE TAB FORSRE COMPLIANCE CALCULATIONS t0.a.wNSwale N115Pec Nl11 0 0 20 000 OLO ON 000 IOb. wat Swale x2(5pee 411 0 0 0 W 000 a- ON O.W .a.Fl[ering Praniapl lSFec Nl21 0 0 m 000 OLO ON 0.0] 11b. Filtering Pori¢w215Fecx12) 0 0 0 0 0 65 000 0L0 13. Wet Ponds Ino RR ]3.a.WHPord.IP,-xId 0 Ili 859 0 3C,.I 30,n. 50 0.19 2106 ]0.62 ]062 13.n wH Pon: xl lLoa3zl Plam)ISper Ala 0 0 0 0 o as 0.0] ot0 0a0 0.0] 13.ewHPonax2lsverxIU 0 0 0 0 0 ]s 0.0] ot0 0a0 0.0] ] 3.a. wH Fond 92(01-tal Pla m)(S Alal 0 0 0 0 0 65 0.0] ot0 0a0 0.0] 6. 0m 1162 -53 ].09 ]. Infiltration Ill) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to FiNer/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. A(T?) 2p26 NOROGEN REMOVED WITH RUNOFF REDUCTION PRACEICES IN D.A. A(Iblyr 12.53 SEE WATER QUALITY COMPLIANCE TAB FOR S OUCUTATIONS(Ijamation Only) 10. Wet Swale (Coastal Plain) (no RR) 11. Filtering Practims(no RR) 12. Constructetl Wetlantl (no RR) 1112 N Nw:_CuM®iu_=petlYrl_� 1'dIDl]-1DkA TOTAL IMPERVIOUS COVER TREATED(a[ 9.00 AREA CHECK: OR. TOTAL MANAGED TURF AREA TREATED (al)6.2] AREA CHECK: OR. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE (Ib/yr 1]90 TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL INOAA(IbM 23.25 TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA-A(Ib/yr 10.62 TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PRACTICFS IN 0AAA(Ib/Yr l.Tl TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED IN D.A. A(Ib/yr 12.36 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN D.A. A(Ib/yr ID SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS HOFF REDUCTION PRACTICES IN DAA(Ib/W 12.53 NOFF REDUCTION PRACTICES INDAA(Ib/yr 05." TOTAL NITROGEN REMOVED IN D.A. A(Ib/yr 58.05 30. ManWatloretl BMP (no RR) Drainage Area g Drainage Aral A UM Cover acres) ASails BSolls CSolls DWis Ta,als lead Cover Rv ..'roADpen sws crawl 0.00 0.00 si-eava TnTlavwl otO [23 1.z3 0.20 ImrerviweCoeeb—) pm ppl 0.]3 0.95 Total Pbospboors Available for Removal in D.A.B(lb/yr) 209 Total 1.93 Post Development Treatment Volumein D.A. B)h°) 3,330 2. Rooftop Disconnection (RR� z a. smple Den nnnxinn to No Sol, (slam( so 0 0 0 0 0 n. pan 0.. 000 E. h. Sl mple Dlsnn-n—m C/Ei Bola Sinn( ss 0 0 0 0 0 1t0 oa0 0.00 ot0 z., To I.d Anonlrd F In, Par, w an aifaa[ana ars gC/D sol)(sps ww) w rtn So 0 D D 0 D nal oaD 0.00 A. z 11 Dry wea m 1-1 o.nny Mmrn-mflm(on wl Islas an) 0 0 n 0 zs aCo om 0.00 AM 1, .To Dry wall nr 1-1, Dean .2 m arn M-om bran wz (spaaxet at D D a 0 zs ant oap o.O] Al zr To o,, Garaan wy 16pswRl ap 0 D n 0 zs oCo oap o.O] AM 4Tn an Garaan wz, se—li earmton w2(1, MI 60 0 D o 0 50 oCo pan o.O] oao z n. To Ralnaats H, rvanng(spaa ws) 0 D D o 0 D oa om 0.00 ow E.. To storan—ter Planter, p rban Oearmt—(Spec N, AppanLa A( B ao 0 0 0 0 Es at0 oN oO] aDo 4. Grass Channel RR) O.a, Gaaa Clonal A/R Sall, (Saw, w3) Eo 0 0 0 aCo oN oO] aC0 an. Grass Clenal C/O saila(Slea 8) to 0 0 0 0 aC0 oM o.O] aC0 a.c Graw CM1amel with Comport Arnervol sail, per alas: lase slaw. of p 0 0 0 0 aC0 con -- In" S., 0ry wale.1(Saver wl0l4. pan 0.00 oC0 s. n Dry Swale wE Rpx N]Ola. 0 0 0 0 w oC0 000 -- oC0 G.a. R'mraton— or or Miam8'rathti net or urban Himereor nlips wal ao 0 0 0 ES 1-oM a- 0Co O. Grass Channel (RR) S. Dry Swale AR) 6. Bioretention )RR) N Nw:_CsM®iu_=p..eYM_� IeAI]-1DkB .. •••`•`•••••• ••••••� •`•`••• Isperw9l BO 09B OW 0 L179 sx, L]13 50 O.O] v]1 154 0.17 ].a.Inflbatiun At lspe ! so 0 o ss o.m oa Pen o.m ]b. In611nrmn w2 eaMI 9B o o ss D.m oa Bm D.m 8. Extended Detention Pond RR) B.a. Lo.1(1, wls) o o D.m ow Bm D.m ab. En.l Prerwlsl Ss 0 0 0 0 is D.m oa Bm D.m TOTALIMPERNOUS COVER TREATED (ac 0.60 AREA CHECK: OR. TOTAL MANAGED TURF AREA TREAFEE (ac) 0.90 AREA CHECK: OR. TOTAL RUNOFF REDUCTION IN D.A. B (fl?) TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN D.A. B(Ib/yr PHOSPHORUS 2.09 TOTAL CES IN D.A. a bIWI TOTAL PHOSPHORUS RFMAINNG AFTER APPLYING RUNOFF REDUCTION PRACTIICES IN D.A. B(Ilb/, 0.55 SEE WATER QUALITY COMPLIANCE TAB FOR SUE COMPLIANCE CALCULATIONS t0.a.wNSwale N115Pec Nl11 0 0 30 OW OLO ON OW IOb. wat Swale xE Praw 411 B 0 0 W OW a- ON O.W .a.Fl[ering Praniapl lSFec Nl11 0 0 m OW OLO ON O.O] SLb. Filtering Porim#rtSPerx11) 0 0 0 0 0 61 OW OLO ON O.O] 13. Wet Ponds Ino RR) Ii.a.w.Ponaxl lspecxId 0 0 0 0 o so o.O] ot0 oN o.O] ]3.n we Puna xl l[oamlwam)ISprrala 0 0 0 0 0 as 0.00 000 Pen 0.00 I1.ewHPonaxll1px Ma) 0 0 0 0 0 ]s 0.O] ot0 oN 0.O] ] i.a. wH Fona 92 (ma#zl wa m) Pa -Alai 0 0 0 0 0 f5 0.O] ot0 oW 0.O] B.BB lzss 1>,ss D.9e ]. Infiltration(RR) S. Extended Detention S. Extended Detention Pond (RR) 9. Sheetflow to FiNer/Open Space (RR) TOTAL RUNOFF REDUCTION IN D.A. 6(f) NITROGEN REMOVED WITH RUNOFF REDUCTION PRARICES IN D.A. B)Ib/Yr 11.25 SEE WATER QUALITY COMPLIANCE TAB FOR SITE CALCULATIONS (I jarmation Only) 10. Wet Swale (Coastal Plain) (no RR) 11. FiRering Practices(no RR) 12. Constructetl Wetlantl (no RR( Le N Nw:_CsM®iu_=p..eYM_� IeAI]-1DkB TOTAL IMPERVIOUS COVER TREATED(ae O.6G AREA CHECK: OR. TOTAL MANAGED TURF AREA TREATED (al)0.9G AREA CHECK: OK. TOTAL PHOSPHORUS REMOVAL REQUIRED ON SITE(Ib/p TOTAL PHOSPHORUS AVAILABLE FOR REMOVAL IN DA. B(IbM 2.09 RICFS TOTAL PHOSPHORUS REMOVED WITHOUT RUNOFF REDUCTION PRAIN DA. B (Ib/yr D.OD TOTAL PHOSPHORUS REMOVED WITH RUNOFF REDUCTION PMLTICFSIN D.A.B(Ib/yr 1.54 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED INDA B(Ib/yr 1.5 TOTAL PHOSPHORUS REMAINING AFTER APPLYING BMP LOAD REDUCTIONS IN DA. B(Ib/yr D.55 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVED WITH RUNOFF REDUCTION PRACTICFSIN D.A. B(Ib/yr 11.25 NITROGEN RFMOVEDWITHOUT RUNOFF REDUCTION PRACTICES IN D.A.B(IDIW D.DO TOTAL NITROGEN REMOVED IN O.A. B(Ib/yr 11.25 14. Manufactured! BMP (no RR) Site Results (Water Quality Compliance) Area Checks FOREST/OPEN SPACE (at) D.A.A 000 I DA.D 0.m 0.0.E 0.00 AREACHECR OK. IMPERVIOUS COVER)a[) 9A3 MD.A.MOM 0.m 0.00 OK. IMPERVOUS COVER TREATm)a[) MANAGED TURF AREA(m) 9.90 6.80 0.m 0.00 0.00 0.00 OK. OK. MANAGED TURF AREA TREATED Ia[) 6.2] 0.00 0.00 OR. ARFACHECR OK OR. OR. OK OR. Site Treatment Volume (ka) 9D543 Runoff Reduction Volume and TP By Drainage Area D.A.A D.A.B DA.0 DA.D 0.0.E TOTAL RUNOFF REDUCTIONVOLUMEACHIEVED 2426 2.09 0 0 6.605 FOR RE OVL(lb/yr) TP LOAD AVAILABLE FOR REMOVAL pb/yil 23.25 2.03 0.00 0.00 O.W 25.39 TP IDAO REDUCTION ACHIEVED )Ib/yil 12.36 1.59 0.00 O.m O.W 13.87 TPLOAO REMAINING IIb/yr) 10.91 0.55 0.m O.m O.W SSA" NUTROGENLOADREDUCTONACHIEVED (Ib/yr)jj 58.05 11.25 0.00 0.00 O.W 69.29 Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD (11b/yr) 2547 TP LOAD REDUCTION REQUIRED IIb/yr) 17.90 TP LOAD REDUCTION ACHIEVED pb/yrl 13.87 TP LOAD REMAINING Qb/yr): 11.60 REMAINING TP LOAD REDUCTION REQUIRED (lb/yr): 4.03 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD (Ib/I)jj 182.23 NMOGEN LOAD REDUCTON ACHIEVED IIb/yrl 69.29 REMAINING POST -DEVELOPMENT NRRWEN LOAD IIb/yr) 112.90 Runoff Volume and Curve Number Calculations Enter design storm rainfall depths (in(: 1-yearoorm 2ryearsmrm 10year storm 3.03 3.66 S53 1/ae NOM Atlm 14 (Mp//Itls.nwtrwvug. /M1LvJpfJyf "Notes (see below): [1] The curve numbers and rumff volumes camp need in this spreadsheet for each tlrainage area are limited in their appliabdity br determine and demonstrating mmphance with water quantity requirements. See Mail Biel, GAdo and Bocu trim ion for additica al inbrmate n. [2]Runoff Volume IR i for pre -and po4Ee elopmee drainage areas must be in volumemc units le.&, acry-f ct or cubic feet) when unng the Energy Balanre Equation. Runoff measured in watershed - inches and shown in the spreadsheet as RViwatershN-inch) an only be used in the Energy Balance Equation when the preandpost tlrrelopment drainage areas are equal. Otherwise RVlwatersheGnch) must be mukiplied N the drainage area. [3] Adjusted CN, are based on runoff reduction volumes as calculated! in Di tabs. An alternative CN adjustment calculation for Vegetated Rooh is included in BMp spenfation No. S. Drainage Area Curve Numbers and Runoff Depths* Curve numbers (CN, Mandl and runoff depths (RV )are computed with and without reduction practices. Drainage AreaA ASoils Bsails CSoils DSoh Teal Area (acres): 16.25 ForesVopen Space- undisturbed, proarded fixtWopen ,pare or rebrested land Area aLfe CN 0.00 3D R. 55 D.DD ]B D.DD ]] Rumff Reduction Volume(R3): 2,426 Mmaged Tuff- admitted, leaded b, yards or other tuff to b, mowed/managed Area acre, CN 2.30 39 0.56 61 D.DD ]< D.DD BD Impervious Cover Ama(acres) CN 1.05 98 8.36 98 D.DD 9B D.DD 9B CNiow Al rs 1-year storm 2-year storm Myear storm RVpeeebpe (watershed -Nit) with no Runoff Reduction" 1.21 1.69 3.26 RVpe emlw4 (ware/shed-hl[hf with Runoff Reduction" 1.17 1.65 3.22 Adjusted Me 79 rt # *See Notes above Drainage Area ASoils Bsails CSoils DSoh Teal Arm Jame:): 1.93 Forest/open Space- undisturbed, proarded brest/open Tore or rebrested land Area (acres) CN 0.00 3D 0ept 55 D.DD ]D D.DD ]] Rumff Reduction Volume R3: 2179 Managed Tuff-d.rt.N d.Sr.dedbry.rds.rothertuf b b, mowed/managed Area acre, CN 0.00 39 1.23 61 D.DD ]< D.DD BD Impervious Cover Ama(acres) CN 0.00 98 0.71 98 D.DD 9B D.DD Siff Chips,A ]5 1-yearstorm 2-yearstorm 16yearrtorm RVpeeawai (watershedRich)with no Runoff Reduction" o.9s 1.42 ze9 RVpemmw4 (ware/shed-hl[hf with Runoff Reduction" c., 1.11 riff Atll dtL CN" w 3o n *See Notes above Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method New Development Compliance Spreadsheet - Version 3.0 LIMP Design Specifications List: 2013 Draft Stds & Specs Site Summary Project Title: Rio Point Date: 44687 Total Rainfall= 43 inches Site Land Cover Summary A soils BSoils Csolls DSoils Totals %of Total Forest/Open (acres( 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 2.30 6.05 0.00 0.00 8.35 45 Impervious Cover (acres) 1.05 9.07 0.00 0.00 10.12 55 18.47 100 Site Tv and Land Cover Nutrient Loads Site Rv 0.60 Treatment Volume ft' 40,543 TP Load (lb/yr) 25.47 TN Load (lb/yr) 182.23 Total TP Load Reduction Required (lb/yr) 17.90 Site Compliance Summary Total Runoff Volume Reduction (ft) 4,605 Total TP Load Reduction Achieved (lb/yr) 13.87 Total TN Load Reduction Achieved (lb/yr) 69.29 Remaining Post Development TP Load 11.60 (lb/yr) Remaining TP Load Reduction (lb/yr) 4.03 Required ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Drainage Area Summary DA. A DA. B D.A. C D.A. D DA. E Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acres) 6.84 1.23 0.00 0.00 0.00 8.07 Impervious Cover (acres) 9.41 0.71 0.00 0.00 0.00 10.12 Total Area (acres) 16.25 1.93 0.00 0.00 0.00 18.18 Drainage Area Compliance Summary D.A. A DA B DA. C D.A. D DA. E Total TP Load Reduced llb/vrl 12.34 1.54 0.00 0.00 0.00 13.87 Summary Print Virginia Runoff Reduction Method Woroineet TN Load Reduced (Ih/yr) 1 58.05 1 11.25 1 0.00 1 0.00 1 0.00 1 69.29 Drainage Area A Summary Land Cover Summary A Soils BSoils CSolls DSoils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 2.30 4.54 0.00 1 0.00 6.84 42 Impervious Cover (acres) 1.05 8.36 0.00 1 0.00 9.41 58 16.25 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Practice Credit Area CoverCreditUpstream I Volume (Tt') to Practice (16s) (16/yr) (Ih/yr) be TreEmploy (acres) Area (acres) practices (Ihz) Employed d Total Impervious Cover Treated(acres) 9.40 Total Turf Area Treated (acres) 6.27 Total TP Load Reduction Achieved in D.A. (lb/yr) 12.34 Total TN Load Reduction Achieved in D.A. (lb/yr) 58.05 Drainage Area B Summary Land Cover Summary A Soils BSoils CSolls DSolis Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acrez) 0.00 1.23 0.00 0.00 1.23 63 Impervious Cover (acres) 1 0.00 1 0.71 0.00 0.00 0.71 37 1.93 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Practice Credit(acres) [over Credit I s Volume (ft) Upstream to Practice (Ihs) (16/yr) (Ih/yr) be TreEmploy (acres) Area (acres) practices (Ihz) Employed d Total Impervious Cover Treated(acres) 0.60 Total Turf Area Treated (acres) 0.90 Total TP Load Reduction Achieved in D.A. (lb/yr) 1.54 Total TN Load Reduction Achieved in D.A. (lb/yr) 11.25 Summary Print Virginia Runoff Reduction Method Worksheet 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) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Practice Credit Area Cover Credit I a Volume (ft) I Upstream to Practice (Ibs) (lb/yr) (lb/yr) Treatmenttobe (acres) Area (acres) Practices (Ibs) Employed Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Drainage Area D Summary Land Cover Summary A Solis B Soils C S011s D Soils Total %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Practice Credit Area Cover Credit I Volume (It') Upstream to Practice (Ibs) (lb/yr) (lb/yr) Treatmenttobe (acres) Area (acres) Practices (Ibs) Employed Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. (lb/yr) 0.00 Total TN Load Reduction Achieved in D.A. (lb/yr) 0.00 Drainage Area E Summary Summary Print Virginia Runoff Reducjon Method Worksheet Land Cover Su anmary A Soils B Soils C So0s D Soils Total %of Total Forest/Open (acres) 0.00 0.00 DOD 0.00 0.00 0 Managed Turf (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 Impervious Cover (acres) 1 0.00 1 0.00 0.00 1 0.00 0.00 1 0 0.00 BMP Selections Managed Turf Impervious BMP Treatment TP Load from Untreated TP Load TP Removed TP Remaining Downstream Practice Credit Area [over Credit I Volume (Tts) Upstream to Practice (Ihs) (Ih/yr) (Ih/yr) Trebe (acres) Area (acres) practices (Ihz) EmployEmployedd Total Impervious Cover Treated(acres) 0.00 Total Turf Area Treated (acres) 0,00 Total TP Load Reduction Achieved in D.A. 0,00 (Ih/yr) Total TN Load Reduction Achieved in D.A. 0,00 (Ih/yr) Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event (in) 1 3.03 3.66 5.53 Drainage Areas RV & CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN 79 75 0 0 0 RR (it) 2,426 2,179 0 0 0 1-year return period RV wa RR(wzin) 1.21 0.98 0.00 0.00 0.00 RV w RR (wsin) 1.17 0.67 0.00 0.00 0.00 CN adjusted 78 69 0 0 0 2-year return period RVwo RR(wzin) 1.69 1.42 0.00 0.00 0.00 RV w RR (wsin) 1.65 1.11 0.00 0.00 0.00 CN adjusted 78 70 0 0 0 10-year return period RV wa RR (wzin) 3.26 2.89 0.00 0.00 0.00 RV w RR Iwsin) 3.22 2.58 0.00 0.00 0.00 CN adjusted 78 71 0 0 0 Summary Print 1S 2S 3S 4S 5S Pre DA Pre DA 2 Pre DA 3 FFSITE - Rio Commons OFFSITE -Road 3L Pre Total to Outfall 1 Subcat Reach OD Link Routing Diagram for PRE DEV Prepared by Timmons Group, Printed 5/6/2022 FHydroCADO 10.10-4a s/n 08663 02020 HydroCAD Software Solutions LLC PRE DEV Prepared by Timmons Group Printed 5/6/2022 Project Notes Rainfall events imported from "NRCS-Rain.txt" for 8784 VA Orange Rainfall events imported from "NRCS-Rain.txt" for 8784 VA Orange Rainfall events imported from "Atlas-14-Rain.txt" for 3557 VA Albemarle Zone-1 PRE DEV Prepared by Timmons Group Printed 5/6/2022 Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 1-Year Type II 24-hr Default 24.00 1 3.03 2 2 10-Year Type II 24-hr Default 24.00 1 5.53 2 3 100-Year Type II 24-hr Default 24.00 1 9.09 2 PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 ©2020 HydroCAD Software Solutions LLC Page 4 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 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 DA 1 Runoff Area=10.716 ac 1.23% Impervious Runoff Depth >0.19" Flow Length=1,024' Tc=9.1 min CN=56 Runoff=1.58 cfs 0.167 of Subcatchment2S: Pre DA 2 Runoff Area=3.843 ac 1.17% Impervious Runoff Depth>0.32" Flow Length=261' Tc=6.8 min CN=61 Runoff=1.79 cfs 0.103 of Subcatchment3S: Pre DA 3 Runoff Area=3.904 ac 0.87% Impervious Runoff Depth>0.19" Flow Length=312' Tc=6.4 min CN=56 Runoff=0.65 cfs 0.061 of Subcatchment4S: OFFSITE- Rio Commons Runoff Area=4.350 ac 8.05% Impervious Runoff Depth>0.29" Flow Length=457' Tc=6.4 min CN=60 Runoff=1.78 cfs 0.106 of Subcatchment5S: OFFSITE- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth>2.59" Tc=6.0 min CN=98 Runoff=1.07 cfs 0.056 of Link 3L: Pre Total to Outfall 1 Inflow=3.03 cfs 0.273 of Primary=3.03 cfs 0.273 of Total Runoff Area = 23.071 ac Runoff Volume = 0.492 of Average Runoff Depth = 0.26" 96.45% Pervious = 22.252 ac 3.55% Impervious = 0.819 ac PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 1S: Pre DA 1 Runoff = 1.58 cfs @ 12.06 hrs, Volume= 0.167 af, Depth> 0.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.132 98 Paved parking, HSG B 2.493 39 >75% Grass cover, Good, HSG A 8.091 61 >75% Grass cover, Good, HSG B 10.716 56 Weighted Average 10.584 98.77% Pervious Area 0.132 1.23% Impervious Area Tc Length Slope Velocity Capacity Description 5.9 100 0.0600 0.28 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 2.7 685 0.0700 4.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.5 239 0.0500 8.79 70.28 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 3.0'/' Top.W=11.00' n= 0.030 Earth, qrassed & windinq 9.1 1,024 Total Subcatchment 1S: Pre DA 1 ❑ Runoff Type II 24-hr 1-Year Rainfall=3.03" Runoff Area=10.716 ac Runoff Volume=0.167 of 1 Runoff Depth>0.19" r� Flow Length=1,024' I I I n Tc=9.1 min CN=56 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 2S: Pre DA 2 Runoff = 1.79 cfs @ 12.01 hrs, Volume= 0.103 af, Depth> 0.32" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.045 98 Paved parking, HSG B 3.798 61 >75% Grass cover, Good, HSG B 3.843 61 Weighted Average 3.798 98.83% Pervious Area 0.045 1.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.4 100 0.0500 0.26 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.4 161 0.1500 6.24 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.8 261 Total Subcatchment 2S: Pre DA 2 Hydrograph ❑ Runoff Type II 24-hr 1-Year Rainfall=3.03" Runoff Area=3.843 ac Runoff Volume=0.103 of Runoff Depth>0.32" Flow Length=261' Tc=6.8 min CN=61 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 3S: Pre DA 3 Runoff = 0.65 cfs @ 12.03 hrs, Volume= 0.061 af, Depth> 0.19" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.034 98 Paved parking, HSG B 0.857 39 >75% Grass cover, Good, HSG A 3.013 61 >75% Grass cover, Good, HSG B 3.904 56 Weighted Average 3.870 99.13% Pervious Area 0.034 0.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.8 100 0.0620 0.29 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.6 212 0.1400 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.4 312 Total Subcatchment 3S: Pre DA 3 Hydrograph 0.7fl ❑Runoff 3 LL 0.1 0. Type II 24-hr 1-Year Rainfall=3.03" Runoff Area=3.904 ac Runoff Volume=0.061 of :--- -Runoff Depth>0.19" -- --- Flow Length=312' ---------- Tc=6.4 min CN=56 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Timmons Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Summary for Subcatchment 4S: OFFSITE - Rio Commons Runoff = 1.78 cfs @ 12.01 hrs, Volume= 0.106 af, Depth> 0.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.350 98 Paved parking, HSG B 0.270 39 >75% Grass cover, Good, HSG A 3.300 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.150 55 Woods, Good, HSG B 4.350 60 Weighted Average 4.000 91.95% Pervious Area 0.350 8.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 100 0.0700 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.7 268 0.1400 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 89 0.0700 16.49 428.82 TrapNee/Rect Channel Flow, Bot.W=23.00' D=1.00' Z= 3.0 7' Top.W=29.00' n= 0.022 Earth, clean & straiaht 6.4 457 Total PRE DEV Timmons Type // 24-hr 1-Year Rainfall=3.03" Subcatchment 4S: OFFSITE - Rio Commons Hydrograph 11 12 13 Time (hours) Printed 5/6/2022 Type II 24ihr 1-Year RainfallT3.03" Runoff Areal=4.350 'ac Runoff'', Vol'',ume=0.'',106''1 of -Runoff -Depth".-29 -- Flow Lehgth=457' Tc=6:4 r"in ON=,60 ■ Runoff PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 5S: OFFSITE - Road Runoff = 1.07 cfs @ 11.96 hrs, Volume= 0.056 af, Depth> 2.59" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 5 6 7 8 9 Subcatchment 5S: OFFSITE - Road Hydrograph Type II 24-hr 1-Year Rainfall=3.03" Runoff Area=0.258 ac Runoff Volume=0.056 of Runoff Depth>2.59" Tc=6.0 min CN=98 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Type // 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Link 3L: Pre Total to Outfall 1 Inflow Area = 15.066 ac, 3.20% Impervious, Inflow Depth > 0.22" for 1-Year event Inflow = 3.03 cfs @ 12.04 hrs, Volume= 0.273 of Primary = 3.03 cfs @ 12.04 hrs, Volume= 0.273 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Pre Total to Outfall 1 Hydrograph FE ]—I n—fl.—. ❑ Primary Time (hours) PRE DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 ©2020 HydroCAD Software Solutions LLC Page 12 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 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 DA 1 Runoff Area=10.716 ac 1.23% Impervious Runoff Depth>1.18" Flow Length=1,024' Tc=9.1 min CN=56 Runoff=20.65 cfs 1.050 of Subcatchment2S: Pre DA 2 Runoff Area=3.843 ac 1.17% Impervious Runoff Depth>1.53" Flow Length=261' Tc=6.8 min CN=61 Runoff=10.93 cfs 0.489 of Subcatchment3S: Pre DA 3 Runoff Area=3.904 ac 0.87% Impervious Runoff Depth>1.18" Flow Length=312' Tc=6.4 min CN=56 Runoff=8.48 cfs 0.383 of Subcatchment4S: OFFSITE- Rio Commons Runoff Area=4.350 ac 8.05% Impervious Runoff Depth>1.46" Flow Length=457' Tc=6.4 min CN=60 Runoff=11.90 cfs 0.527 of Subcatchment5S: OFFSITE- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth>4.85" Tc=6.0 min CN=98 Runoff=1.98 cfs 0.104 of Link 3L: Pre Total to Outfall 1 Inflow=31.97 cfs 1.578 of Primary=31.97 cfs 1.578 of Total Runoff Area = 23.071 ac Runoff Volume = 2.554 of Average Runoff Depth = 1.33" 96.45% Pervious = 22.252 ac 3.55% Impervious = 0.819 ac PRE DEV Timmons Type II 24-hr 10-Year Rainfall=5.53" Summary for Subcatchment 1S: Pre DA 1 Runoff = 20.65 cfs @ 12.02 hrs, Volume= 1.050 af, Depth> 1.18" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.132 98 Paved parking, HSG B 2.493 39 >75% Grass cover, Good, HSG A 8.091 61 >75% Grass cover, Good, HSG B 10.716 56 Weighted Average 10.584 98.77% Pervious Area 0.132 1.23% Impervious Area Tc Length Slope Velocity Capacity Description 5.9 100 0.0600 0.28 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 2.7 685 0.0700 4.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.5 239 0.0500 8.79 70.28 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 3.07' Top.W=11.00' n= 0.030 Earth, qrassed & windinq 9.1 1,024 Total Subcatchment 1S: Pre DA 1 23 -,--------r----r- -1----r----r---r----r---r- 1 ❑Runoff 1 Pe.55 ay 1 21 20 ---------1�----1-- ----1--------1---�, Type II 24-hr - 10-Year Rainfall=5.53" 18 ----------------------I --- -- 7 I - - --' ---, r -;------1'-- --- 1---- Runoff Area=10.716 ac 15 ___J____;____IAL-J ----1- Runoff Volume=1.050 of 14 -1 -T r -1 F 13 ____I____ ____I____ ____1_----1-- ___ -Runoff Depth>1.1.8" 1 -- --- - ----------7----r--- - ---- Flow Length=1,024' 9 ------------------1---------1- -I I I I I I - 1 I I I Trc=9 1 min 7 T CN=56 5 I -y -T -I -Y 4 I 1 I 2 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 2S: Pre DA 2 Runoff = 10.93 cfs @ 11.99 hrs, Volume= 0.489 af, Depth> 1.53" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.045 98 Paved parking, HSG B 3.798 61 >75% Grass cover, Good, HSG B 3.843 61 Weighted Average 3.798 98.83% Pervious Area 0.045 1.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.4 100 0.0500 0.26 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.4 161 0.1500 6.24 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.8 261 Total Subcatchment 2S: Pre DA 2 Hydrograph 12 ---------------------r----i-- 6 -----------------I 9 8 7 -------------------------I- N --------------------- ----'- ;6 0 LL 5 4 I I I 3 � � � � � � � � ■Runoff Type II 24-hr 10-Year Rainfall=5.53" --- Runoff Area=3.843 ac ---,Runoff Volume=0.489 of Runoff Depth>1.53" Flow Length=261' Tc=6.8 min CN=61 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 3S: Pre DA 3 Runoff = 8.48 cfs @ 11.99 hrs, Volume= 0.383 af, Depth> 1.18" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.034 98 Paved parking, HSG B 0.857 39 >75% Grass cover, Good, HSG A 3.013 61 >75% Grass cover, Good, HSG B 3.904 56 Weighted Average 3.870 99.13% Pervious Area 0.034 0.87% Impervious Area Tc Length Slope iin) (feet) (ft/ft) 5.8 100 0.0620 0.6 212 0.1400 6.4 312 Total Capacity Description 0.29 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps Subcatchment 3S: Pre DA 3 BAB ch -I-- 8 7 -----------'---- 6 u 5 E 4 1 . 2 Type II 24-hr 10-Year Rainfall=5.53" Runoff Area=3.904 ac Runoff Volume=0.383 of Runoff Depth>1.18" Flow Length=312' Tc=6.4 min CN=56 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Subcatchment 4S: OFFSITE - Rio Commons Runoff = 11.90 cfs @ 11.99 hrs, Volume= 0.527 af, Depth> 1.46" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.350 98 Paved parking, HSG B 0.270 39 >75% Grass cover, Good, HSG A 3.300 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.150 55 Woods, Good, HSG B 4.350 60 Weighted Average 4.000 91.95% Pervious Area 0.350 8.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 100 0.0700 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.7 268 0.1400 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 89 0.0700 16.49 428.82 TrapNee/Rect Channel Flow, Bot.W=23.00' D=1.00' Z= 3.0 7' Top.W=29.00' n= 0.022 Earth, clean & straiaht 6.4 457 Total PRE DEV Type // 24-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 5 6 7 Subcatchment 4S: OFFSITE - Rio Commons 11 Hydrograph Time (hours) ----'-Tyres-W24 ku- IO Year-Otairifa1 5:5319 - RunWAreA=4.-35flac- rttu off,`VolurmL=0:,52tat Runof(D-" 1-1461" Flow Lehgt-h=457'- T, :F ,4_rain-- r--- tN ,60- --- T--- '7---;--- r ---I'I T 7 ■ RunoH PRE DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 5S: OFFSITE - Road Runoff = 1.98 cfs @ 11.96 hrs, Volume= 0.104 af, Depth> 4.85" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: OFFSITE - Road Hydrograph 2-Type II 24-hr 10-Year Rainfall=5.53" Runoff Area=0.258 ac Runoff Volume=0.104 of " Runoff Depth>4.85" I Tc=6.0 min CN=98 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Link 3L: Pre Total to Outfall 1 Inflow Area = 15.066 ac, 3.20% Impervious, Inflow Depth > 1.26" for 10-Year event Inflow = 31.97 cfs @ 12.01 hrs, Volume= 1.578 of Primary = 31.97 cfs @ 12.01 hrs, Volume= 1.578 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Pre Total to Outfall 1 Hydrograph 34 31. 32 3 --____+--------+---" 28 __ 28 24 22 2 � I I I I 14 �I 12 -- -- - - - - r---- r I 1 � I I I ___-----------r---I 8 a Inflow Area=15.066 ac I I I I I I I I I _L _J _ IL __ I 1 - -li __ -r 8 9 10 11 12 13 14 Time (hours) ❑ Inflow ❑ Primary PRE DEV Type //24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 © 2020 HydroCAD Software Solutions LLC Page 20 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 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 DA 1 Runoff Area=10.716 ac 1.23% Impervious Runoff Depth>3.35" Flow Length=1,024' Tc=9.1 min CN=56 Runoff=61.60 cfs 2.989 of Subcatchment2S: Pre DA 2 Runoff Area=3.843 ac 1.17% Impervious Runoff Depth>3.94" Flow Length=261' Tc=6.8 min CN=61 Runoff=28.12 cfs 1.263 of Subcatchment3S: Pre DA 3 Runoff Area=3.904 ac 0.87% Impervious Runoff Depth>3.35" Flow Length=312' Tc=6.4 min CN=56 Runoff=24.73 cfs 1.090 of Subcatchment4S: OFFSITE- Rio Commons Runoff Area=4.350 ac 8.05% Impervious Runoff Depth>3.82" Flow Length=457' Tc=6.4 min CN=60 Runoff=31.27 cfs 1.386 of Subcatchment5S: OFFSITE- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth>8.04" Tc=6.0 min CN=98 Runoff=3.26 cfs 0.173 of Link 3L: Pre Total to Outfall 1 Inflow=91.66 cfs 4.376 of Primary=91.66 cfs 4.376 of Total Runoff Area = 23.071 ac Runoff Volume = 6.901 of Average Runoff Depth = 3.59" 96.45% Pervious = 22.252 ac 3.55% Impervious = 0.819 ac PRE DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Summary for Subcatchment 1S: Pre DA 1 Runoff = 61.60 cfs @ 12.01 hrs, Volume= 2.989 af, Depth> 3.35" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.132 98 Paved parking, HSG B 2.493 39 >75% Grass cover, Good, HSG A 8.091 61 >75% Grass cover, Good, HSG B 10.716 56 Weighted Average 10.584 98.77% Pervious Area 0.132 1.23% Impervious Area Tc Length Slope Velocity Capacity Description 5.9 100 0.0600 0.28 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 2.7 685 0.0700 4.26 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.5 239 0.0500 8.79 70.28 TrapNee/Rect Channel Flow, Bot.W=5.00' D=1.00' Z= 3.0'/' Top.W=11.00' n= 0.030 Earth, qrassed & windinq 9.1 1,024 Total Subcatchment 1S: Pre DA 1 65 ei 60 55 50 45 40 N 3 35 0 30 ------------- 25 20 15 10 Type II 24-hr 100-Year Rainfall=9.09" Runoff Area=10.716 ac Runoff Volume=2.989 of Runoff Depth>3.35" Flow Length=1,024' Tc=9.1 min CN=56 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Type //24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 2S: Pre DA 2 Runoff = 28.12 cfs @ 11.98 hrs, Volume= 1.263 af, Depth> 3.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.045 98 Paved parking, HSG B 3.798 61 >75% Grass cover, Good, HSG B 3.843 61 Weighted Average 3.798 98.83% Pervious Area 0.045 1.17% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.4 100 0.0500 0.26 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.4 161 0.1500 6.24 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 6.8 261 Total Subcatchment 2S: Pre DA 2 Hydrograph ❑ Runoff 28 ----------- - - - - -------- - - - -- 26 I 24 22 20 18 0 16 14 I LL ,2 10 4 Type II 24-hr 100-Year Rainfall=9.09" - Runoff Area=3.843 ac --- Runoff Volume=1.263 of Runoff Depth>3.94" Flow Length=261' Tc=6.8 min-- CN=61-- 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) PRE DEV Type //24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 3S: Pre DA 3 Runoff = 24.73 cfs @ 11.98 hrs, Volume= 1.090 af, Depth> 3.35" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.034 98 Paved parking, HSG B 0.857 39 >75% Grass cover, Good, HSG A 3.013 61 >75% Grass cover, Good, HSG B 3.904 56 Weighted Average 3.870 99.13% Pervious Area 0.034 0.87% Impervious Area Tc Length Slope tin) (feet) (ft/ft) 5.8 100 0.0620 0.6 212 0.1400 6.4 312 Total 1 Capacity Description 0.29 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps Subcatchment 3S: Pre DA 3 24.s h - Type II 24-hr 100-Year Rainfall=9.09" Runoff Area=3.904 ac -- ---- Runoff Volume=1.090 of Runoff Depth>3.35" Flow Length=312' Tc=6.4 min CN=56 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Subcatchment 4S: OFFSITE - Rio Commons Runoff = 31.27 cfs @ 11.98 hrs, Volume= 1.386 af, Depth> 3.82" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.350 98 Paved parking, HSG B 0.270 39 >75% Grass cover, Good, HSG A 3.300 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.150 55 Woods, Good, HSG B 4.350 60 Weighted Average 4.000 91.95% Pervious Area 0.350 8.05% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.6 100 0.0700 0.30 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.7 268 0.1400 6.02 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.1 89 0.0700 16.49 428.82 TrapNee/Rect Channel Flow, Bot.W=23.00' D=1.00' Z= 3.0 7' Top.W=29.00' n= 0.022 Earth, clean & straiaht 6.4 457 Total PRE DEV Type 1124-hr 100-YearRainfa11=9.09" Prepared by Timmons Group Printed 5/6/2022 Subcatchment 4S: OFFSITE - Rio Commons Hydrograph 34 _r _, _r _r _i _Y ■Runoff C 32 - -- ---31---- ------.----L---J-TYP1(24- e-30 -- y= F-r- -- 26 ----____r_ ,_ ,_----i-4A0 Year- ltainfaM-4.Q9"-- I- 26 -- - -- - ------ Runi fi`Are&4.350'ac 22 _ -- �i---- i—ft"Offi V-0�ufn9=1.dO6-af - 20 - -- ---- - - -T- - - .F- cn_o_ ffDoth-;482 v 18 ---------,----___ T_R__ Y -r -7 -I -? -r -7 -Y -I -Y 16 -Flow- Flow-'- LL ___�____i____i____1____L____I__ ____I____1___ - III____I 14 ___1____IL___JI__ __ _ __1i___ ---J----i----'- 1----L---�-- 12 I c=8��4 Ill 10 - --------- - - - ----- - - - - ------------------ ---- - ,-tN= 60 - 6 ----------- -----= ---4 6 4 5 6 7 8 9 10 11 12 13 Time (hours) PRE DEV Type //24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 5S: OFFSITE - Road Runoff = 3.26 cfs @ 11.96 hrs, Volume= 0.173 af, Depth> 8.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: OFFSITE - Road Hydrograph 3 N .2 .V.. I LL I I 1 i II I Type II 24-hr 100-Year Rainfall=9.09" Runoff Area=0.258 ac Runoff Volume=0.173 of Runoff Depth>8.04" Tc=6.0 min CN=98 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ❑ Runoff PRE DEV Type //24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Link 3L: Pre Total to Outfall 1 Inflow Area = 15.066 ac, 3.20% Impervious, Inflow Depth > 3.49" for 100-Year event Inflow = 91.66 cfs @ 12.00 hrs, Volume= 4.376 of Primary = 91.66 cfs @ 12.00 hrs, Volume= 4.376 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Link 3L: Pre Total to Outfall 1 Hydrograph 100 __J____I____ L___ J____L___ 91.88 da I ' Inflow Area=15.066 ac ss---J----I so ' as I ' 80 I 7o 6560 - I -y -I i i -I -Y -T 55 •' 50 .' I 0 LL 45 - - ___J___J____L___J___J__ __L___1___J____1___J____L___L__ 35 30 ' I I____r___�____I__ 25 ___ ___ L 20 '-------------------- 15 10 6 7 8 9 10 11 12 13 14 Time (hours) FE ]-I n-fl.-. ❑ Primary 1S 2S 6S 7S 4S 3S SS POST A 1A POST DA 1 B POST FFSITE - Rio ffsite - Road P ST DA 1 C POS DA 2A pOS DA 2B ommons 12 BIO 1A\\ 10 8L SO Total Pond 17 Wet and 14L 15L Total to Outfall 2 Total to Outfall 1 Subcat Reach OD Link Routing Diagram for POST DEV Prepared by Timmons Group, Printed 5/6/2022 HydroCADO 10.10-4a s/n 08663 02020 HydroCAD Software Solutions LLC POST DEV Timmons Project Notes Rainfall events imported from "NRCS-Rain.txt" for 8784 VA Orange Rainfall events imported from "NRCS-Rain.txt" for 8784 VA Orange Rainfall events imported from "Atlas-14-Rain.txt" for 3557 VA Albemarle Zone-1 Printed 5/6/2022 POST DEV Timmons Rainfall Events Listing (selected events) Event# Event Storm Type Curve Mode Duration B/B Depth AMC Name (hours) (inches) 1 1-Year Type II 24-hr Default 24.00 1 3.03 2 2 10-Year Type II 24-hr Default 24.00 1 5.53 2 3 100-Year Type II 24-hr Default 24.00 1 9.09 2 Printed 5/6/2022 POST DEV Type/1 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 ©2020 HydroCAD Software Solutions LLC Page 4 Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: POST DA 1A Runoff Area=1.161 ac 69.42% Impervious Runoff Depth=1.69" Tc=6.0 min CN=86 Runoff=3.35 cfs 0.163 of Subcatchment2S: POST DA 1 B Runoff Area=14.499 ac 59.22% Impervious Runoff Depth=1.27" Tc=9.4 min CN=80 Runoff=28.55 cfs 1.538 of Subcatchment3S: POST DA 2A Runoff Area=1.500 ac 39.93% Impervious Runoff Depth=1.04" Flow Length=255' Tc=8.3 min CN=76 Runoff=2.48 cfs 0.129 of Subcatchment4S: POST DA 1 C Runoff Area=0.589 ac 3.06% Impervious Runoff Depth=0.06" Flow Length=119' Tc=6.3 min CN=48 Runoff=0.00 cfs 0.003 of Subcatchment5S: POST DA 2B Runoff Area=0.435 ac 25.06% Impervious Runoff Depth=0.73" Tc=6.0 min CN=70 Runoff=0.53 cfs 0.026 of Subcatchment6S: POST OFFSITE - Rio Runoff Area=4.350 ac 44.14% Impervious Runoff Depth=0.93" Tc=6.0 min CN=74 Runoff=6.92 cfs 0.336 of Subcatchment7S: Offsite- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth=2.80" Tc=6.0 min CN=98 Runoff=1.07 cfs 0.060 of Pond 10P: BID 2A Peak EIev=440.60' Storage=2,084 cf Inflow=2.48 cfs 0.129 of Outflow=0.33 cfs 0.129 of Pond 12P: BID 1A Peak EIev=444.52' Storage=2,392 cf Inflow=3.35 cfs 0.163 of Outflow=0.78 cfs 0.163 of Pond 17P: Wet Pond Peak EIev=421.05' Storage=71,027 cf Inflow=36.75 cfs 2.097 of Outflow=0.47 cfs 2.071 of Link 8L: Total to Pond Inflow=36.75 cfs 2.097 of Primary=36.75 cfs 2.097 of Link 14L: Total to Outfall 1 Inflow=0.47 cfs 2.074 of Primary=0.47 cfs 2.074 of Link 15L: Total to Outfall 2 Inflow=0.76 cfs 0.156 of Primary=0.76 cfs 0.156 of Total Runoff Area = 22.792 ac Runoff Volume = 2.256 of Average Runoff Depth = 1.19" 46.05% Pervious = 10.496 ac 53.95% Impervious = 12.296 ac POST DEV Prepared by Timmons Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Summary for Subcatchment 1S: POST DA 1A Runoff = 3.35 cfs @ 11.97 hrs, Volume= 0.163 af, Depth= 1.69" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.806 98 Paved parking, HSG B 0.338 61 >75% Grass cover, Good, HSG B 0.017 39 >75% Grass cover, Good, HSG A 1.161 86 Weighted Average 0.355 30.58% Pervious Area 0.806 69.42% Impervious Area Tc Length Capacity Description t-f..x 6.0 Direct Entry, Subcatchment 1S: POST DA 1A Hydrograph Type II 24-hr 3 1-Year Rainfall=3.03" Runoff Area=1.161 ac Runoff Volume=0.163 of 21 Runoff Depth=1.69" Tc=6.0 min 1 i I I I CN=86 30 35 40 60 65 70 i5 80 85 90 95 101 ❑ Runoff POST DEV Timmons Type/1 24-hr 1-Year Rainfall=3.03" Summary for Subcatchment 2S: POST DA 1 B Runoff = 28.55 cfs @ 12.01 hrs, Volume= 1.538 af, Depth= 1.27" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 8.586 98 Paved parking 1.890 39 >75% Grass cover, Good, HSG A 4.023 61 >75% Grass cover, Good, HSG B 14.499 80 Weighted Average 5.913 40.78% Pervious Area 8.586 59.22% Impervious Area Tc Length Capacity Description 9.4 Direct Entry, Tc from Pipe Calcs Subcatchment 2S: POST DA 1B Hydrograph I I I I I 30 2855 crs I I I I I I I I I I I 28 }-------------------------- Type II 24-hr - - -- - -- - - --, - '_--_ 7-Year Rainfall=3.03"-- 2s _ r_ I _ I_ I _ L I 24 T---,---;------r--,-- - 22 L__�___I_R_uI n-off __ A_r_e_ a=14._4_ 9I _9__a_c 26 _-_TlTnO _V^14jnq--J r___rr_r__r_r7-08_o 18 I - Runof :Depth--C2P .V.. 3 16 o �_T___r r___I_ r___I___r__1___r__T___r__r___I_ 1 14 12 _ ICN=80 �I_ ___I___L___I___ L__ L___! __!___I___ ___IL I I I I I I I I I I I I I I I I I 10 I I I I I I I I I I I I I 8- - - - IL I I I I I I I I I I I I I I I I I I 6 I I I I 2 I I I I I I - 0 5 10 15 20 1 35 40 1 60 65 70 i5 :1 85 90 95 101 ❑ Runoff POST DEV Type/1 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 3S: POST DA 2A Runoff = 2.48 cfs @ 12.00 hrs, Volume= 0.129 af, Depth= 1.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.599 98 0.901 61 1.500 76 Weighted Average 0.901 60.07% Pervious Area 0.599 39.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 100 0.0800 0.22 Sheet Flow, Grass: Dense n= 0.240 P2= 3.66" 0.2 52 0.0770 4.47 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 103 0.0780 4.50 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.3 255 Total Subcatchment 3S: POST DA 2A Hydrograph ❑ Runoff Type II 24-hr 1-Year Rainfall=3.03" 21 1 1 1 Runoff Area=1.500 ac Runoff Volume=0.129 of t J I 1A Runoff Depth=1.04" Flow Length=255' 'I I I l Tc=8.3 min CN=76 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Timmons Type/1 24-hr 1-Year Rainfall=3.03" Summary for Subcatchment 4S: POST DA 1 C Runoff = 0.00 cfs @ 14.91 hrs, Volume= 0.003 af, Depth= 0.06" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.018 98 Paved parking, HSG B 0.181 61 >75% Grass cover, Good, HSG B 0.390 39 >75% Grass cover, Good, HSG A 0.589 48 Weighted Average 0.571 96.94% Pervious Area 0.018 3.06% Impervious Area Tc Length Capacity Description 6.2 100 0.0530 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.1 19 0.0500 4.54 Shallow Concentrated Flow, Paved Kv= 20.3 fps 6.3 119 Total Subcatchment 4S: POST DA 1C Hydrograph O.00a------------ 0.004 i 000 ch 0.004 --�---- -----=----------------'---� ---- Type II 24-hr 0.004 ; - I 1-Year Rainfall=3-.03" 0.003�I I I � � � � 1 0.003 -- i-- _� __ �p y ...I -__L-------- L--�----- Runof AteA=0,589-Ac 1 0.003 ---,------illr--, ' ' ' runoff Vplu,me=0,.003 of 0.003 0.002 I-- Runoff Depth=0.06" - 0.002 LL - flowLehgtb-4a9' - 0 002 0.002 - --�- -'L-- ----T=$.3 min --- -- ------ -- ------ -----�q I I I 0.001 —Y � 1 —Y —Y —I —Y —7 —I —Y —Y —I —T 0.001 --'�- I 1 1 1---r--i---r--r--i---r--r-- �---r--r---i---r--, 1 1 0.000 1 1 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) ❑ Runoff POST DEV Timmons Type/1 24-hr 1-Year Rainfall=3.03" Summary for Subcatchment 5S: POST DA 2B Runoff = 0.53 cfs @ 11.99 hrs, Volume= 0.026 af, Depth= 0.73" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.109 98 Paved parking, HSG B 0.326 61 >75% Grass cover, Good, HSG B 0.435 70 Weighted Average 0.326 74.94% Pervious Area 0.109 25.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST DA 2B Hydrograph I I I I I I I I I I I I 0.55 o.$3 CC! I 0.5 Type II 24-hr I I I I I I I I t r 1-Year Rainfall=3.03" 0.45 0.4 .-'�, - --- Runoff Area=0.435 ac Runoff Volume=0.026 of ---I---�-----I---� -- �- 0.35 I I I I I I I w-------r------------ Runoff Depth=0.73" I I I I 0.3--LI---IL--i-----i--LI---Ii --i-- ° Tc=6.0 min 0.25 I I I I I I I I I I I o.z 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 0.15 I I I I I I I I I I I I I I I I I I 0.1 1--- I___L__J--- I___L__J--- L_____ 0.05 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (horns) ❑ Runoff POST DEV Type/1 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 6S: POST OFFSITE - Rio Commons Runoff = 6.92 cfs @ 11.98 hrs, Volume= 0.336 af, Depth= 0.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 1.920 98 Paved parking 0.270 39 >75% Grass cover, Good, HSG A 1.830 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.050 55 Woods, Good, HSG B 4.350 74 Weighted Average 2.430 55.86% Pervious Area 1.920 44.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 5 2 Subcatchment 6S: POST OFFSITE - Rio Commons Hydrograph ________________________________ I I I I I I I I I I I Type II 24-hr 1-Year Rainfall=3.03" Runoff Area=4.350 ac Runoff Volume=0.336 of -- -Runoff Depth=0.93" Tc=6.0 min I I I I I I I I I I I CN=74 ---- -- 'I- I I F I I I I I I I I I I I I I I I I I I I 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) ❑ Runoff POST DEV Prepared by Timmons Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Summary for Subcatchment 7S: Offsite - Road Runoff = 1.07 cfs @ 11.96 hrs, Volume= 0.060 af, Depth= 2.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 1-Year Rainfall=3.03" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 7S: Offsite - Road Hydrograph ❑ Runoff Type II 24-hr 1 1-Year Rainfall=3.03" Runoff Area=0.258 ac Runoff Volume=0.060 of Runoff Depth=2.80" Tc=6.0 min I I I I CN=98 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Type/1 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 10P: BIO 2A Inflow Area = 1.500 ac, 39.93% Impervious, Inflow Depth = 1.04" for 1-Year event Inflow = 2.48 cfs @ 12.00 hrs, Volume= 0.129 of Outflow = 0.33 cfs @ 12.43 hrs, Volume= 0.129 af, Atten= 87%, Lag= 25.5 min Primary = 0.33 cfs @ 12.43 hrs, Volume= 0.129 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 440.60' @ 12.43 hrs Surf.Area= 2,482 sf Storage= 2,084 cf Plug -Flow detention time= 79.5 min calculated for 0.129 of (100% of inflow) Center -of -Mass det. time= 79.0 min ( 936.6 - 857.6 ) Volume Invert Avail.Storage Storage Description #1 438.50' 9,869 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 438.50 2,482 0.0 0 0 438.51 2,482 40.0 10 10 440.75 2,482 40.0 2,224 2,234 440.76 2,482 25.0 6 2,240 445.00 2,482 25.0 2,631 4,871 445.01 2,482 100.0 25 4,896 445.50 3,040 100.0 1,353 6,249 446.50 4,201 100.0 3,621 9,869 Device Routing Invert Outlet Devices #1 Primary 438.50' 15.0" Round Culvert L= 28.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 438.50' / 437.50' S= 0.0348 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 438.50' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 445.50' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.33 cfs @ 12.43 hrs HW=440.60' (Free Discharge) t1=Culvert (Passes 0.33 cfs of 7.17 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.33 cfs @ 6.76 fps) 3=S harp-C rested Rectangular Weir( Controls 0.00 cfs) POST DEV Prepared by Timmons i Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Pond 10P: BIO 2A Hydrograph Infl' w' Area=7.50d ac --P-eAk Pfev::"Q,6W - Storage2,08r4 of 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) ■ Inflow ■ Primary POST DEV Type 11 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 12P: BIO 1A Inflow Area = 1.161 ac, 69.42% Impervious, Inflow Depth = 1.69" for 1-Year event Inflow = 3.35 cfs @ 11.97 hrs, Volume= 0.163 of Outflow = 0.78 cfs @ 12.14 hrs, Volume= 0.163 af, Atten= 77%, Lag= 10.1 min Primary = 0.78 cfs @ 12.14 hrs, Volume= 0.163 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 444.52' @ 12.14 hrs Surf.Area= 2,650 sf Storage= 2,392 cf Plug -Flow detention time= 38.8 min calculated for 0.163 of (100% of inflow) Center -of -Mass det. time= 38.2 min ( 860.0 - 821.8 ) Volume Invert Avail.Storage Storage Description #1 440.92' 7,510 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 440.92 2,650 0.0 0 0 440.93 2,650 40.0 11 11 441.50 2,650 25.0 378 388 445.25 2,650 25.0 2,484 2,873 445.26 2,650 100.0 26 2,899 447.00 2,650 100.0 4,611 7,510 Device Routing Invert Outlet Devices #1 Primary 440.92' 15.0" Round Culvert L= 125.3' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 440.92' / 440.29' S= 0.0050 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 440.92' 4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 446.00' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.78 cfs @ 12.14 hrs HW=444.52' (Free Discharge) t1=Culvert (Passes 0.78 cfs of 9.46 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.78 cfs @ 8.92 fps) 3=S harp-C rested Rectangular Weir( Controls 0.00 cfs) POST DEV Prepared by Timmons Type // 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Pond 12P: BIO 1A Hydrograph ■Inflow 33s ors ■Primary __Inflow Area=1.161-aic 3 '�, '�, '�, '�, '�, Pehk;Elev=444�5g' Storage=2,392 cf 2 3 LL 1 O.lB Cs i i i i 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) POST DEV Timmons Type/1 24-hr 1-Year Rainfall=3.03" Summary for Pond 17P: Wet Pond Printed 5/6/2022 Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 1.24" for 1-Year event Inflow = 36.75 cfs @ 12.00 hrs, Volume= 2.097 of Outflow = 0.47 cfs @ 24.04 hrs, Volume= 2.071 af, Atten= 99%, Lag= 722.0 min Primary = 0.47 cfs @ 24.04 hrs, Volume= 2.071 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 421.05' @ 24.04 hrs Surf.Area= 27,982 sf Storage= 71,027 cf Plug -Flow detention time=1,678.0 min calculated for 2.070 of (99% of inflow) Center -of -Mass det. time= 1,672.0 min ( 2,518.7 - 846.7 ) Volume Invert Avail.Storage Storage Description #1 417.00' 252,680 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 417.00 15,636 0 0 418.00 1,843 8,740 8,740 419.00 21,468 11,656 20,395 420.00 24,591 23,030 43,425 421.00 27,815 26,203 69,628 422.00 31,141 29,478 99,106 423.00 35,467 33,304 132,410 424.00 38,093 36,780 169,190 425.00 41,720 39,907 209,096 426.00 45,447 43,584 252,680 Device Routing Invert Outlet Devices #1 Primary 410.74' 48.0" Round Culvert L= 128.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 410.74' / 409.53' S= 0.0094 '/' Cc= 0.900 n= 0.013, Flow Area= 12.57 sf #2 Device 1 417.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 422.00' 16.0' long Sharp -Crested Rectangular Weir End Contraction(s) Primary OutFlow Max=0.47 cfs @ 24.04 hrs HW=421.05' (Free Discharge) L1=Culvert (Passes 0.47 cfs of 174.42 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.47 cfs @ 9.54 fps) 3=S harp-C rested Rectangular Weir( Controls 0.00 cfs) POST DEV Type/1 24-hr 1-Year Rainfall=3.03" d by Timmons Group Printed 5/6/2022 D® 10.10-4a s/n 08663 © 2020 HydroCAD Software Solutions LLC Page 17 Pond 17P: Wet Pond Hydrograph ---r----------r--r--- -- - - -r--r-- --r---I---r--r-- -_7__ ■Inflow -________I__-I I I I ri---i �______r---i---r--r- L--J---1---L--J------L--L---I-I--J------L--J------I- �Pnma ry L 1r�#Igw'At '-20:2-6$ -ap - ' -- -' ---- }--;---';POC -€levy=42t.01 r------r--r--r---r--r--r---I ,I n - -I ---IStbra � i I {/ _J I I I I I I I I I I I i I I � _ I I _r--r---I---r__r__r---r__r__�---i-- r- ---- r-- r--r---I---r-- 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 _r--r---I---r__ 11__ 1--11 --- I---r--r---r--r-_ L__J__J___ L__J___ I___ L__ I 25 30 35 40 45 50 55 60 65 70 75 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Summary for Link 8L: Total to Pond Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 1.24" for 1-Year event Inflow = 36.75 cfs @ 12.00 hrs, Volume= 2.097 of Primary = 36.75 cfs @ 12.00 hrs, Volume= 2.097 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 8L: Total to Pond Hydrograph - -,-- - - -i - -- r--r-- ______r__-__ ___� ❑ Inflow i i sass as - [I Primary 38 Imflow Area=20.268 ac 36 34 ' 32 '� 30 28 26 ' _ 24 22 .' e20.' i i 16 14 ; 121 __; .r__r___ 10_____--- --- ___ _________J ________1__J__� ___ 1___ I___ I__ 8 _ ____I____________I______I 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) POST DEV Type/1 24-hr 1-Year Rainfall=3.03" Prepared by Timmons Group Printed 5/6/2022 Summary for Link 14L: Total to Outfall 1 Inflow Area = 20.857 ac, 55.56% Impervious, Inflow Depth > 1.19" for 1-Year event Inflow = 0.47 cfs @ 24.00 hrs, Volume= 2.074 of Primary = 0.47 cfs @ 24.00 hrs, Volume= 2.074 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 14L: Total to Outfall 1 Hydrograph ■ Inflow ■ Primary Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 1-Year Rainfall=3.03" Printed 5/6/2022 Summary for Link 15L: Total to Outfall 2 Inflow Area = 1.935 ac, 36.59% Impervious, Inflow Depth = 0.97" for 1-Year event Inflow = 0.76 cfs @ 12.00 hrs, Volume= 0.156 of Primary = 0.76 cfs @ 12.00 hrs, Volume= 0.156 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 15L: Total to Outfall 2 Hydrograph 0.85 076 O.9 076 ch I I I I ,' 0.75 0.7 0.6 0.55 0.5 I I I I `. 0.45 p 0.4 I I I 0.35 I I 0.3 0.25 02 I I I I 0.1 ____ ❑Inflow ❑Primary Inflow Area=1.935 ac I I __r__r__-___r__r__T___I___r__r__r___I___r 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 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 _L _1 _J _I _L__1 _J _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 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Time (hours) POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 ©2020 HydroCAD Software Solutions LLC Page 21 Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: POST DA 1A Runoff Area=1.161 ac 69.42% Impervious Runoff Depth=3.96" Tc=6.0 min CN=86 Runoff=7.59 cfs 0.384 of Subcatchment2S: POST DA 1 B Runoff Area=14.499 ac 59.22% Impervious Runoff Depth=3.36" Tc=9.4 min CN=80 Runoff=74.83 cfs 4.060 of Subcatchment3S: POST DA 2A Runoff Area=1.500 ac 39.93% Impervious Runoff Depth=2.98" Flow Length=255' Tc=8.3 min CN=76 Runoff=7.21 cfs 0.372 of Subcatchment4S: POST DA 1 C Runoff Area=0.589 ac 3.06% Impervious Runoff Depth=0.80" Flow Length=119' Tc=6.3 min CN=48 Runoff=0.65 cfs 0.039 of Subcatchment5S: POST DA 2B Runoff Area=0.435 ac 25.06% Impervious Runoff Depth=2.44" Tc=6.0 min CN=70 Runoff=1.85 cfs 0.088 of Subcatchment6S: POST OFFSITE - Rio Runoff Area=4.350 ac 44.14% Impervious Runoff Depth=2.79" Tc=6.0 min CN=74 Runoff=20.91 cfs 1.013 of Subcatchment7S: Offsite- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth=5.29" Tc=6.0 min CN=98 Runoff=1.98 cfs 0.114 of Pond 10P: BID 2A Peak Elev=445.72' Storage=6,958 cf Inflow=7.21 cfs 0.372 of Outflow=1.03 cfs 0.372 of Pond 12P: BID 1A Peak Elev=446.46' Storage=6,078 cf Inflow=7.59 cfs 0.384 of Outflow=2.10 cfs 0.383 of Pond 17P: Wet Pond Peak Elev=422.52' Storage=115,938 cf Inflow=97.56 cfs 5.570 of Outflow=20.18 cfs 5.504 of Link 8L: Total to Pond Inflow=97.56 cfs 5.570 of Primary=97.56 cfs 5.570 of Link 14L: Total to Outfall 1 Inflow=20.32 cfs 5.543 of Primary=20.32 cfs 5.543 of Link 15L: Total to Outfall 2 Inflow=2.37 cfs 0.461 of Primary=2.37 cfs 0.461 of Total Runoff Area = 22.792 ac Runoff Volume = 6.070 of Average Runoff Depth = 3.20" 46.05% Pervious = 10.496 ac 53.95% Impervious = 12.296 ac POST DEV Prepared by Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Subcatchment 1S: POST DA 1A Runoff = 7.59 cfs @ 11.97 hrs, Volume= 0.384 af, Depth= 3.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.806 98 Paved parking, HSG B 0.338 61 >75% Grass cover, Good, HSG B 0.017 39 >75% Grass cover, Good, HSG A 1.161 86 Weighted Average 0.355 30.58% Pervious Area 0.806 69.42% Impervious Area Tc Length Capacity Description t-f..x 6.0 Direct Entry, Subcatchment 1S: POST DA 1A Hydrograph Type II 24-hr 10-Year Rainfall=5.53" 6 Runoff Area=1.161 ac Runoff Volume=0.384 of .5 Runoff Depth=3.96" Tc=6.0 min 3 CN=86 2 1 30 35 40 60 65 70 i5 80 85 90 95 161 ❑ Runoff POST DEV Timmons Type II 24-hr 10-Year Rainfall=5.53" Summary for Subcatchment 2S: POST DA 1 B Runoff = 74.83 cfs @ 12.01 hrs, Volume= 4.060 af, Depth= 3.36" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 8.586 98 Paved parking 1.890 39 >75% Grass cover, Good, HSG A 4.023 61 >75% Grass cover, Good, HSG B 14.499 80 Weighted Average 5.913 40.78% Pervious Area 8.586 59.22% Impervious Area Tc Length L 75 70 60 55 50 N -T 45 c 40 u 35 30 25 --�-- 20 15 10 Capacity Description Direct Entry, Tc from Pipe Calcs Subcatchment 2S: POST DA 1B Hydrograph I I I I I Type II 24-hr -- - 10-Year Rainfall=5.53" -{--- :---II_ --------i--_II-Runoff Area=14.499 ac I i i I I I i i - Runoff Volume=4.060 at- -�---�---�---II---�--36"-- I - - iI --- i --II --- I I I ---i------Tc=9IA-'Imhv- _ _r---i--r___-r__r---r__7___r__T___rr____r__r_CV -$Q_ 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___II___ 7___II___i__J___Ir__JI___ t I -h -{ -F -Y -F -{ -I -h --I -F L 60 65 70 i5 iO 85 90 95 161 ❑ Runoff POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 3S: POST DA 2A Runoff = 7.21 cfs @ 12.00 hrs, Volume= 0.372 af, Depth= 2.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.599 98 0.901 61 1.500 76 Weighted Average 0.901 60.07% Pervious Area 0.599 39.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 100 0.0800 0.22 Sheet Flow, Grass: Dense n= 0.240 P2= 3.66" 0.2 52 0.0770 4.47 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 103 0.0780 4.50 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.3 255 Total Subcatchment 3S: POST DA 2A Hydrograph ❑ Runoff 7 Type II 24-hr 10-Year Rainfall=5.53" 6 Runoff Area=1.500 ac 5 Runoff Volume=0.372 of Runoff Depth=2.98" E 4 Flow Length=255' 3 Tc=8.3 min CN=76 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 4S: POST DA 1 C Runoff = 0.65 cfs @ 12.00 hrs, Volume= 0.039 af, Depth= 0.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.018 98 Paved parking, HSG B 0.181 61 >75% Grass cover, Good, HSG B 0.390 39 >75% Grass cover, Good, HSG A 0.589 48 Weighted Average 0.571 96.94% Pervious Area 0.018 3.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.2 100 0.0530 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.1 19 0.0500 4.54 Shallow Concentrated Flow, Paved Kv= 20.3 fps 6.3 119 Total Subcatchment 4S: POST DA 1C Hydrograph 0 7 '1 ❑Runoff 0.1 0. Type II 24-hr I I I I 10-Year Rainfall=5.53" ___-__ Runoff Area=0.589 ac I I r Runoff Volume=0.039 of I I - --'I Runoff Depth=0.80" Flow Length=119' = Tc=6.3 min I I I I I I I I I I I I I I I I I I I I CN=48 I I I I I I I I I I I I I I I I I I I y _F _y _I _} _y _I 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Subcatchment 5S: POST DA 2B Runoff = 1.85 cfs @ 11.98 hrs, Volume= 0.088 af, Depth= 2.44" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.109 98 Paved parking, HSG B 0.326 61 >75% Grass cover, Good, HSG B 0.435 70 Weighted Average 0.326 74.94% Pervious Area 0.109 25.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, 2 Subcatchment 5S: POST DA 2B Hydrograph Type II 24-hr 10-Year Rainfall=5.53" Runoff Area=0.435 ac Runoff Volume=0.088 of Runoff Depth=2.44" Tc=6.0 min CN=70 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) ❑ Runoff POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 6S: POST OFFSITE - Rio Commons Runoff = 20.91 cfs @ 11.97 hrs, Volume= 1.013 af, Depth= 2.79" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 1.920 98 Paved parking 0.270 39 >75% Grass cover, Good, HSG A 1.830 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.050 55 Woods, Good, HSG B 4.350 74 Weighted Average 2.430 55.86% Pervious Area 1.920 44.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 6S: POST OFFSITE - Rio Commons Hydrograph 23 _. I I __._____ I , I _____. I , I ❑Runoff 22-- 20 ei cts T---I---r---r --r--r---r-r--r --r---r -- 21 __.------------L--L---------------I- Type II 24-hr ,g _ ; I - _; �I 10B-Y3" ea,raR1lt�arnin�f.35 17 -____ -__--- F-_R���-M�d---`� 16 - T - r l _ _- r __;�I_____�-_- -T f 14 --------- - - - a - =a1-1-=-5- if 13 -_-_-_II__-_-_ ---r--,---r--,---r-T-R66-fibe--279F `=- 3 , I o „ --�-- ----I---I I----------�--�---�---------a---I- =6 b - LL 1p r__ I _r--- i__r___I___r___I___r__7___r__r___I___r___I___r___I___r__1___ I I I I I I I I I I I I I I I I I Ca I 8 -i -i _I _♦ -I -4 -y _F _� .MVP -F -♦ -I -a -I -4 _-I y 7 __7__ I _7--- i__r___I___r___I___r__7___r__r___I___r___I___r___I___r__1___ I _1___I___1---I___L__J___L__1_--L__1___L__1__!___L__J-__L__J___ 5 _� I _I _4 _I _f _I _F _♦ _I _a _I _4 f _I _F _y 4 ----___r__* --- r--r------ r--1--- r--r--- r--r-----r------r-----. 3 L__L--- L__J--- I--- i___I__ L__L___L I I 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Subcatchment 7S: Offsite - Road Runoff = 1.98 cfs @ 11.96 hrs, Volume= 0.114 af, Depth= 5.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=5.53" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 7S: Offsite - Road Hydrograph ❑ Runoff 2 1 Type II 24-hr 10-Year Rainfall=5.53" Runoff Area=0.258 ac Runoff Volume=0.114 of Runoff Depth=5.29" Tc=6.0 min A `N 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 10P: BIO 2A Inflow Area = 1.500 ac, 39.93% Impervious, Inflow Depth = 2.98" for 10-Year event Inflow = 7.21 cfs @ 12.00 hrs, Volume= 0.372 of Outflow = 1.03 cfs @ 12.33 hrs, Volume= 0.372 af, Atten= 86%, Lag= 19.7 min Primary = 1.03 cfs @ 12.33 hrs, Volume= 0.372 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 445.72' @ 12.33 hrs Surf.Area= 3,300 sf Storage= 6,958 cf Plug -Flow detention time=113.1 min calculated for 0.372 of (100% of inflow) Center -of -Mass det. time= 113.7 min ( 940.3 - 826.7 ) Volume Invert Avail.Storage Storage Description #1 438.50' 9,869 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 438.50 2,482 0.0 0 0 438.51 2,482 40.0 10 10 440.75 2,482 40.0 2,224 2,234 440.76 2,482 25.0 6 2,240 445.00 2,482 25.0 2,631 4,871 445.01 2,482 100.0 25 4,896 445.50 3,040 100.0 1,353 6,249 446.50 4,201 100.0 3,621 9,869 Device Routing Invert Outlet Devices #1 Primary 438.50' 15.0" Round Culvert L= 28.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 438.50' / 437.50' S= 0.0348 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 438.50' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 445.50' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=1.03 cfs @ 12.33 hrs HW=445.72' (Free Discharge) t1=Culvert (Passes 1.03 cfs of 15.18 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.63 cfs @ 12.83 fps) 3=S harp-C rested Rectangular Weir(Weir Controls 0.40 cfs @ 1.54 fps) POST DEV Type // 24-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 0 LL Pond 10P: BIO 2A Hydrograph _T 'Z1 Ch 'I -T -1 T -1 Inflpw Area=�.50� arc Pe#k Bev :446,7:r- -- I i I � � � I I I I i I Ir--I--�I---T--r--T---r--r--�---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 as crs I I I I I I I I 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) ■ Inflow ■ Primary POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 12P: BIO 1A Inflow Area = 1.161 ac, 69.42% Impervious, Inflow Depth = 3.96" for 10-Year event Inflow = 7.59 cfs @ 11.97 hrs, Volume= 0.384 of Outflow = 2.10 cfs @ 12.12 hrs, Volume= 0.383 af, Atten= 72%, Lag= 9.1 min Primary = 2.10 cfs @ 12.12 hrs, Volume= 0.383 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 446.46' @ 12.12 hrs Surf.Area= 2,650 sf Storage= 6,078 cf Plug -Flow detention time= 50.0 min calculated for 0.383 of (100% of inflow) Center -of -Mass det. time= 49.1 min ( 846.6 - 797.5 ) Volume Invert Avail.Storage Storage Description #1 440.92' 7,510 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 440.92 2,650 0.0 0 0 440.93 2,650 40.0 11 11 441.50 2,650 25.0 378 388 445.25 2,650 25.0 2,484 2,873 445.26 2,650 100.0 26 2,899 447.00 2,650 100.0 4,611 7,510 Device Routing Invert Outlet Devices #1 Primary 440.92' 15.0" Round Culvert L= 125.3' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 440.92' / 440.29' S= 0.0050 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 440.92' 4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 446.00' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=2.06 cfs @ 12.12 hrs HW=446.45' (Free Discharge) t1=Culvert (Passes 2.06 cfs of 12.14 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.97 cfs @ 11.15 fps) 3=S harp-C rested Rectangular Weir(Weir Controls 1.08 cfs @ 2.19 fps) POST DEV 7 6 _ 5 0 4 M 3- 2- 0 0 5 Timmons Pond 12P: BIO 1A Hydrograph Type/1 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 I I I I I I I I I I I I I I I 7.59 ck I I I I I - Inflpw�4rea-a.�61 a� I li � I I I I I I I I I I I I I I I r ! ! + Q�rE[0v 44�41F-- I I I I I I I I I I I Storage,6,078 of I I I I I I I I I I I I __________________________ �I li i i i li li li li i i li 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 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 P 19 cfs 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 r___r__r__r__l___r__r__r___r I I I I I I I I I I 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) ■ Inflow ■ Primary POST DEV Timmons Type II 24-hr 10-Year Rainfall=5.53" Summary for Pond 17P: Wet Pond Printed 5/6/2022 Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 3.30" for 10-Year event Inflow = 97.56 cfs @ 12.00 hrs, Volume= 5.570 of Outflow = 20.18 cfs @ 12.26 hrs, Volume= 5.504 af, Atten= 79%, Lag= 15.6 min Primary = 20.18 cfs @ 12.26 hrs, Volume= 5.504 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 422.52' @ 12.26 hrs Surf.Area= 33,398 sf Storage= 115,938 cf Plug -Flow detention time=1,063.4 min calculated for 5.504 of (99% of inflow) Center -of -Mass det. time= 1,056.1 min ( 1,876.3 - 820.2 ) Volume Invert Avail.Storage Storage Description #1 417.00' 252,680 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 417.00 15,636 0 0 418.00 1,843 8,740 8,740 419.00 21,468 11,656 20,395 420.00 24,591 23,030 43,425 421.00 27,815 26,203 69,628 422.00 31,141 29,478 99,106 423.00 35,467 33,304 132,410 424.00 38,093 36,780 169,190 425.00 41,720 39,907 209,096 426.00 45,447 43,584 252,680 Device Routing Invert Outlet Devices #1 Primary 410.74' 48.0" Round Culvert L= 128.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 410.74' / 409.53' S= 0.0094 '/' Cc= 0.900 n= 0.013, Flow Area= 12.57 sf #2 Device 1 417.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 422.00' 16.0' long Sharp -Crested Rectangular Weir End Contraction(s) Primary OutFlow Max=20.05 cfs @ 12.26 hrs HW=422.52' (Free Discharge) L1=Culvert (Passes 20.05 cfs of 189.22 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.55 cfs @ 11.18 fps) 3=S harp-C rested Rectangular Weir(Weir Controls 19.50 cfs @ 2.36 fps) POST DEV Timmons Pond 17P: Wet Pond Hydrograph Type // 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 _ ___r __r __y______r__t__y______r__y___�___r__r__y___i___r__Y__ erssar I_ _-'-- _______ ____l_________'__- f40_A,rE IIIIIIII F _F Peak Elev=432.53'- I I I I I I I I I I I I I I I $te=ah-5;831,8 -qf- I I I I I I I I I I I I I I I I I I I I I I I r _1 I I _L _L _J _I _L _1 _J _I I _L _1I _I _ IL _1 _JI _I _L _J I I I I I I I I I I I I I I I--r--r I I — �---I___r__r__,___r--r--I__ 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) ■ Inflow ■ Primary POST DEV Prepared by Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Link 8L: Total to Pond Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 3.30" for 10-Year event Inflow = 97.56 cfs @ 12.00 hrs, Volume= 5.570 of Primary = 97.56 cfs @ 12.00 hrs, Volume= 5.570 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 8L: Total to Pond Hydrograph ❑ Inflow _ - 1197 ch i ❑ Primary 56 105 100 ess°f -- —�--------1--�-- ----- Inflow Area=20.268 ac 95 ' 90 __r _r__r-_r __r __r _r__r___ 85 . . -----------------�---� 75 70 65 �-" 60 � - ... 55 -_,___- __r__7__,___i i - - __r__+ __r__r___r __r 0 7__�___r 50 ----_L__i__J___I___�__ LL 45 40 __r 35 30 25 20 ___r______r__r______ ____________ r__7___ r__ r__ 15 10 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type II 24-hr 10-Year Rainfall=5.53" Printed 5/6/2022 Summary for Link 14L: Total to Outfall 1 Inflow Area = 20.857 ac, 55.56% Impervious, Inflow Depth > 3.19" for 10-Year event Inflow = 20.32 cfs @ 12.26 hrs, Volume= 5.543 of Primary = 20.32 cfs @ 12.26 hrs, Volume= 5.543 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 14L: Total to Outfall 1 Hydrograph __-- 1 ------r--r-----'___I - ❑Inflow 22 _ _J 20.32 C8 '__ _ '__ _ _ '__ __ _I _1 _J _L _L _J _L ❑Primary 21�'� -'_°'�� _1- _1 y _7 _r _r Inflow Area=20.857 ac 20 I I I I I 18 �' r__r__-___r__r__r___ 17 .' __ I _I___1__J_I___L__JILJ_ I I I I I I I_L__ 16 ,� 15 14 I I 1 13 i 12 --7 -r--r---r--r--r--7---r--7--7---r--r--1---r--r--7---r--r L__L__L___I___1__J__J___L__J___I___ L__ p 16 LL __y 1 1 _I___t___-___r__t__y___r__t__y___I___t__y___1___r__y___I___r. 9 1 1 1 I I I I I 1 1 1 1 I I I 7 ,' , � __' 1 '___r___'___r__*__r___r__r__r___r__*_--__--- _-r_-r__- 6 '. �' __ �I 1 1 1 1 1 1 ---1-- ---r- 5 4 ' - - � _____ ____Jr__r__�___'r-----_--_--- r---- I---r-- � 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) POST DEV Type 1124-hr 10-Year Rainfall=5.53" Prepared by Timmons Group Printed 5/6/2022 Summary for Link 15L: Total to Outfall 2 Inflow Area = 1.935 ac, 36.59% Impervious, Inflow Depth = 2.86" for 10-Year event Inflow = 2.37 cfs @ 11.98 hrs, Volume= 0.461 of Primary = 2.37 cfs @ 11.98 hrs, Volume= 0.461 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 15L: Total to Outfall 2 Hydrograph FE ]—I n—fl.—. ❑ Primary Time (hours) POST DEV Type // 24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 HydroCAD® 10.10-4a s/n 08663 ©2020 HydroCAD Software Solutions LLC Page 38 Time span=0.00-100.00 hrs, dt=0.05 hrs, 2001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: POST DA 1A Runoff Area=1.161 ac 69.42% Impervious Runoff Depth=7.39" Tc=6.0 min CN=86 Runoff=13.62 cfs 0.715 of Subcatchment2S: POST DA 1 B Runoff Area=14.499 ac 59.22% Impervious Runoff Depth=6.65" Tc=9.4 min CN=80 Runoff=143.87 cfs 8.039 of Subcatchment3S: POST DA 2A Runoff Area=1.500 ac 39.93% Impervious Runoff Depth=6.16" Flow Length=255' Tc=8.3 min CN=76 Runoff=14.54 cfs 0.770 of Subcatchment4S: POST DA 1 C Runoff Area=0.589 ac 3.06% Impervious Runoff Depth=2.70" Flow Length=119' Tc=6.3 min CN=48 Runoff=2.70 cfs 0.132 of Subcatchment5S: POST DA 2B Runoff Area=0.435 ac 25.06% Impervious Runoff Depth=5.41" Tc=6.0 min CN=70 Runoff=4.01 cfs 0.196 of Subcatchment6S: POST OFFSITE - Rio Runoff Area=4.350 ac 44.14% Impervious Runoff Depth=5.91" Tc=6.0 min CN=74 Runoff=43.23 cfs 2.143 of Subcatchment7S: Offsite- Road Runoff Area=0.258 ac 100.00% Impervious Runoff Depth=8.85" Tc=6.0 min CN=98 Runoff=3.26 cfs 0.190 of Pond 10P: BIO 2A Peak Elev=453.24' Storage=9,869 cf Inflow=14.54 cfs 0.770 of Outflow=22.20 cfs 0.770 of Pond 12P: BIO 1A Peak Elev=456.63' Storage=7,510 cf Inflow=13.62 cfs 0.715 of Outflow=21.29 cfs 0.720 of Pond 17P: Wet Pond Peak Elev=423.98' Storage=168,532 cf Inflow=209.13 cfs 11.092 of Outflow=142.95 cfs 11.025 of Link 8L: Total to Pond Inflow=209.13 cfs 11.092 of Primary=209.13 cfs 11.092 of Link 14L: Total to Outfall 1 Inflow=144.45 cfs 11.158 of Primary=144.45 cfs 11.158 of Link 15L: Total to Outfall2 Inflow=24.65 cfs 0.966 of Primary=24.65 cfs 0.966 of Total Runoff Area = 22.792 ac Runoff Volume = 12.186 of Average Runoff Depth = 6.42" 46.05% Pervious = 10.496 ac 53.95% Impervious = 12.296 ac POST DEV Type 1124-hr 100-YearRainfa11=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Subcatchment 1S: POST DA 1A Runoff = 13.62 cfs @ 11.96 hrs, Volume= 0.715 af, Depth= 7.39" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Descriotion 0.806 98 Paved parking, HSG B 0.338 61 >75% Grass cover, Good, HSG B 0.017 39 >75% Grass cover, Good, HSG A 1.161 86 Weighted Average 0.355 30.58% Pervious Area 0.806 69.42% Impervious Area Tc Length Description 6.0 Direct Entry, Subcatchment 1S: POST DA 1A Hydrograph I I I I I 15 I I I I I I I I I I I I I I I I --- -I -- -I - - -' -- -�---'-- -I - - - - - - - -j_ I_ : ---- :Type''rr4 -I;ir- 13 1 � 12- '100-Year Rainfal'11=9.09rr I I 1 1 4so alc- 1___ _L _I _L _J _L I I I I I I I I I I I I I I I a off-vol _I = Riun------------- off;6�pt=7�.3`�- Tc=B.D' min _1___:___L__JL__L___ L__1___1___ L___1___ L__J__ L 1 5 1 1 : : 1 1 1 : -' _-' _-' _-' --' - -_' - 'CN=-fr- 5 : : T 1 : : 1 1 1 : 4- 3 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Time (hours) ■ Runoff POST DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Summary for Subcatchment 2S: POST DA 1 B Runoff = 143.87 cfs @ 12.00 hrs, Volume= 8.039 af, Depth= 6.65" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 8.586 98 Paved parking 1.890 39 >75% Grass cover, Good, HSG A 4.023 61 >75% Grass cover, Good, HSG B 14.499 80 Weighted Average 5.913 40.78% Pervious Area 8.586 59.22% Impervious Area Tc Length Capacity Description 9.4 Direct Entry, Tc from Pipe Calcs Subcatchment 2S: POST DA 1B Hydrograph 160 150 1143 e] ch 140 i --- T - -, -- I I I I I Type II 24-hr _ I ,36 1 III- !!II1100-Year Rainfall=9.09" -;-- -- - ---;---I� - --- 120 I -- --II - --II --- --I - ` � Runoff Area=14.499 ac 10 ,66 ---- --------I,--,---I, --; -----I- --Runoff Volume=8.0-$IIOyf _ `� 90___L__J___L__J .V.. Runoff 0� cq I --- I_�VVO 0 -7 -T -I -T -1 -I -T 1 -I -T T -1 ri— n M 76 .41mllI 66 - - - I I I I I I I I I I I I I I I I - -- = I�` II - --------------------------------------------- 50 I I I I I I I I I I I I I I I I I I I I _f _y _t 40 30 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 20 I I I I I I I I I I I I I I I I I I I I I 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Time (hours) ❑ Runoff POST DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Summary for Subcatchment 3S: POST DA 2A Runoff = 14.54 cfs @ 11.99 hrs, Volume= 0.770 af, Depth= 6.16" Printed 5/6/2022 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.599 98 0.901 61 1.500 76 Weighted Average 0.901 60.07% Pervious Area 0.599 39.93% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 7.7 100 0.0800 0.22 Sheet Flow, Grass: Dense n= 0.240 P2= 3.66" 0.2 52 0.0770 4.47 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 0.4 103 0.0780 4.50 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 8.3 255 Total Subcatchment 3S: POST DA 2A Hydrograph 16 ------------ ----- ❑Runoff 15 f454 cfs 14 I-------------L--J--- -- Type II 24-hr 13 100-Year Rainfall=9.09rr 11 ---'-------'--------`--'- Runoff Area=1.500 ac- 10-- ---7------r------r-- ---r-- Runoff Volume=0.770 of 8 -- -- - ---� -----�,--- ------ -- - - -� -- -Runoff Depth=6. 6"- Flow Lehgh��25� E 7 = IL --; 6 I I I T�= min-- _r---r--r___r--r__r___r__1___r__T___r__r___.__ .3'�, 5- 5 i --i-- -+--- + ---+- 'CIS-76 4 i i i i 3 i 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Subcatchment 4S: POST DA 1 C Runoff = 2.70 cfs @ 11.99 hrs, Volume= 0.132 af, Depth= 2.70" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.018 98 Paved parking, HSG B 0.181 61 >75% Grass cover, Good, HSG B 0.390 39 >75% Grass cover, Good, HSG A 0.589 48 Weighted Average 0.571 96.94% Pervious Area 0.018 3.06% Impervious Area Tc Length Capacity Description t-f..x 6.2 100 0.0530 0.27 Sheet Flow, Grass: Short n= 0.150 P2= 3.66" 0.1 19 0.0500 4.54 Shallow Concentrated Flow, Paved Kv= 20.3 fps 6.3 119 Total Subcatchment 4S: POST DA 1C Hydrograph 3 ❑ Runoff Type II 24-hr 100-Year Rainfall=9.09" Runoff Area=0.589 ac 2 Runoff Volume=0.132 of Runoff Depth=2.70" Flow Length=119' Tc=6.3 min CN=48 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Subcatchment 5S: POST DA 2B Runoff = 4.01 cfs @ 11.97 hrs, Volume= 0.196 af, Depth= 5.41" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.109 98 Paved parking, HSG B 0.326 61 >75% Grass cover, Good, HSG B 0.435 70 Weighted Average 0.326 74.94% Pervious Area 0.109 25.06% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST DA 2B Hydrograph 4 Type II 24-hr 100-Year Rainfall=9.09" Runoff Area=0.435 ac 3 Runoff Volume=0.196 of Runoff Depth=5.41" LL 2 Tc=6.0 min CN=70 1 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (horns) ❑ Runoff POST DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Subcatchment 6S: POST OFFSITE - Rio Commons Runoff = 43.23 cfs @ 11.97 hrs, Volume= 2.143 af, Depth= 5.91" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 1.920 98 Paved parking 0.270 39 >75% Grass cover, Good, HSG A 1.830 61 >75% Grass cover, Good, HSG B 0.280 30 Woods, Good, HSG A 0.050 55 Woods, Good, HSG B 4.350 74 Weighted Average 2.430 55.86% Pervious Area 1.920 44.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 6S: POST OFFSITE - Rio Commons Hydrograph 48- ----------- -- r- ----r------r--T---Ir- ❑Runoff 46 --1___L__1___i___1___1___L__1___1__1___L__1___1___ 44 42 --, --'I-- ---- T------r------T----------------'--- -'I I-- Type II 24-hr 49 T I---r---1---T-------------r400-Year Rainfall=9.09rr 38 --;-- 36 ---1---� Runoff Area=4.350 ac 32 ---- +---'--`---'---' ---' ---' -_,. 30 --L-- -1-__I___1___1___L__J_ ___L___ Runoff Volume=2.143 of 28 .r 26 ,--- ' __-__ 1 r____r____r__r ------- -- I_ --------I---�-Runoff 1 Depth=5.91" - 24 3 0 22 _-4__ -i_ __F_-i__I___ ---_---I--Tz=6.0 min - LL 29 _1 _1 _I _1 _I _L _J _L _1 _L _1 _I _1 _I _L. I i 18 --r-- I -r--r--r___r--r__r---r--J---r--r---r--r---r--r-- I /emu_ ''\.II\�74 16 __ �__ -1------1---___L---___L1IiIi_Ir__ �I___ �__. 14 -4 -i -I -t -I -h -y -F -Y -F -T -I 12 __ �__ 1 1 r--r r___1_ - -- 1 __ r__r___r__7___r__T___r 1 1 1 __ __ r___I_ r__r___r__�__. _L__1 _I___1 _I___L _J___L _J 8 -Y -T -i -Y 6 I 1 1 ! 1 I__I_ 1 1 1 I I 1 1 1 I __ 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Subcatchment 7S: Offsite - Road Runoff = 3.26 cfs @ 11.96 hrs, Volume= 0.190 af, Depth= 8.85" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=9.09" Area (ac) CN Description 0.258 98 Paved parking, HSG B 0.258 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 7S: Offsite - Road Hydrograph Type II 24-hr 3 100-Year Rainfall=9.09" Runoff Area=0.258 ac Runoff Volume=0.190 of 2 Runoff Depth=8.85" Tc=6.0 min CN=98 1 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Time (hours) ❑ Runoff POST DEV Type // 24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 10P: BIO 2A [931 Warning: Storage range exceeded by 6.74' [881 Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.500 ac, 39.93% Impervious, Inflow Depth = 6.16" for 100-Year event Inflow = 14.54 cfs @ 11.99 hrs, Volume= 0.770 of Outflow = 22.20 cfs @ 12.05 hrs, Volume= 0.770 af, Atten= 0%, Lag= 3.3 min Primary = 22.20 cfs @ 12.05 hrs, Volume= 0.770 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 453.24' @ 12.05 hrs Surf.Area= 4,201 sf Storage= 9,869 cf Plug -Flow detention time= 87.0 min calculated for 0.770 of (100% of inflow) Center -of -Mass det. time= 86.2 min ( 892.1 - 806.0 ) Volume Invert Avail.Storage Storage Description #1 438.50' 9,869 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 438.50 2,482 0.0 0 0 438.51 2,482 40.0 10 10 440.75 2,482 40.0 2,224 2,234 440.76 2,482 25.0 6 2,240 445.00 2,482 25.0 2,631 4,871 445.01 2,482 100.0 25 4,896 445.50 3,040 100.0 1,353 6,249 446.50 4,201 100.0 3,621 9,869 Device Routing Invert Outlet Devices #1 Primary 438.50' 15.0" Round Culvert L= 28.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 438.50' / 437.50' S= 0.0348 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 438.50' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 445.50' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=22.16 cfs @ 12.05 hrs HW=453.19' (Free Discharge) t1=Culvert (Inlet Controls 22.16 cfs @ 18.06 fps) �2=Orifice/Grate (Passes < 0.90 cfs potential flow) 3=S harp-C rested Rectangular Weir(Passes < 41.87 cfs potential flow) POST DEV Type // 24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 � 1 = 1 3 1 LL 1 Pond 10P: BIO 2A Hydrograph -- I I I I i I I I I I I I I I I I I I I ■ InflOW Plimary , -zzsn------+-----i---�--i===lr==lr inflO_P�reeml.600ai� I I I I I I I I I I I I I I I I--- 1,11--11 --- 11--1--11-- fe#k;Ekv�4 3el ------------ I I I I I I I +I + stora-cf- , . 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 __ __ I___I___I __ I___I___I __ , I 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 Time (hours) POST DEV Type 11 24-hr 100-Year Rainfall=9.09" Prepared by Timmons Group Printed 5/6/2022 Summary for Pond 12P: BIO 1A [931 Warning: Storage range exceeded by 9.63' [881 Warning: Qout>Qin may require smaller dt or Finer Routing Inflow Area = 1.161 ac, 69.42% Impervious, Inflow Depth = 7.39" for 100-Year event Inflow = 13.62 cfs @ 11.96 hrs, Volume= 0.715 of Outflow = 21.29 cfs @ 12.00 hrs, Volume= 0.720 af, Atten= 0%, Lag= 2.2 min Primary = 21.29 cfs @ 12.00 hrs, Volume= 0.720 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs / 3 Peak Elev= 456.63' @ 12.00 hrs Surf.Area= 2,650 sf Storage= 7,510 cf Plug -Flow detention time= (not calculated: outflow precedes inflow) Center -of -Mass det. time= 38.5 min ( 818.8 - 780.3 ) Volume Invert Avail.Storage Storage Description #1 440.92' 7,510 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Voids Inc.Store Cum.Store (feet) (sq-ft) (%) (cubic -feet) (cubic -feet) 440.92 2,650 0.0 0 0 440.93 2,650 40.0 11 11 441.50 2,650 25.0 378 388 445.25 2,650 25.0 2,484 2,873 445.26 2,650 100.0 26 2,899 447.00 2,650 100.0 4,611 7,510 Device Routing Invert Outlet Devices #1 Primary 440.92' 15.0" Round Culvert L= 125.3' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 440.92' / 440.29' S= 0.0050 '/' Cc= 0.900 n= 0.010, Flow Area= 1.23 sf #2 Device 1 440.92' 4.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 446.00' 1.2' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=21.23 cfs @ 12.00 hrs HW=456.54' (Free Discharge) t1=Culvert (Barrel Controls 21.23 cfs @ 17.30 fps) �2=Orifice/Grate (Passes < 1.65 cfs potential flow) 3=S harp-C rested Rectangular Weir(Passes < 67.16 cfs potential flow) POST DEV LL , Type II 24-hr 100-Year Rainfall=9.09" d by Timmons Group Printed 5/6/2022 D® 10.10-4a s/n 08663 0 2020 HydroCAD Software Solutions LLC Page 49 Pond 12P: BIO 1A Hydrograph ■Inw ___rL__L__J__J___I___L r_C_ i_E__Iie__V_r_�I6__8__6__r'---- rI 0Pnmary ------r--r-i�flOW-Area= -161-ac-L L__LLL - ' I --=I -- ----- --- Stor-g7,MOUT __E_ (4C1 L -- _L _L _J _L -L -J -I_ _L _J _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 1 I I I I I I I I I I I I I I , � 1 I / 1 I r___1___r__r__r___r__r__r___r__r__I___I___r__r___i___r__ , / 1 1 I r___1___r__r__-___r__r__7___I___r_____I___r__r______r__ __J___l__L__J___l_-L__J__J___1__J__J___L-_J-__ILi -I -F -! -y -F -h -4 -I -1 -y -I -h -4 -I -h Ul 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 Time (hours) POST DEV Timmons Type/1 24-hr 100-Year Rainfall=9.09" Summary for Pond 17P: Wet Pond Printed 5/6/2022 Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 6.57" for 100-Year event Inflow = 209.13 cfs @ 12.00 hrs, Volume= 11.092 of Outflow = 142.95 cfs @ 12.07 hrs, Volume= 11.025 af, Atten= 32%, Lag= 4.5 min Primary = 142.95 cfs @ 12.07 hrs, Volume= 11.025 of Routing by Stor-Ind method, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Peak Elev= 423.98' @ 12.07 hrs Surf.Area= 38,048 sf Storage= 168,532 cf Plug -Flow detention time= 547.8 min calculated for 11.020 of (99% of inflow) Center -of -Mass det. time= 545.9 min ( 1,346.3 - 800.4 ) Volume Invert Avail.Storage Storage Description #1 417.00' 252,680 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 417.00 15,636 0 0 418.00 1,843 8,740 8,740 419.00 21,468 11,656 20,395 420.00 24,591 23,030 43,425 421.00 27,815 26,203 69,628 422.00 31,141 29,478 99,106 423.00 35,467 33,304 132,410 424.00 38,093 36,780 169,190 425.00 41,720 39,907 209,096 426.00 45,447 43,584 252,680 Device Routing Invert Outlet Devices #1 Primary 410.74' 48.0" Round Culvert L= 128.7' CMP, square edge headwall, Ke= 0.500 Inlet / Outlet Invert= 410.74' / 409.53' S= 0.0094 '/' Cc= 0.900 n= 0.013, Flow Area= 12.57 sf #2 Device 1 417.00' 3.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 422.00' 16.0' long Sharp -Crested Rectangular Weir End Contraction(s) Primary OutFlow Max=139.15 cfs @ 12.07 hrs HW=423.95' (Free Discharge) L1=Culvert (Passes 139.15 cfs of 202.54 cfs potential flow) �2=Orifice/Grate (Orifice Controls 0.62 cfs @ 12.57 fps) 3=S harp-C rested Rectangular Weir(Weir Controls 138.53 cfs @ 4.56 fps) POST DEV Type 1124-hr 100-YearRainfa11=9.09" Prepared by Timmons Group Printed 5/6/2022 Pond 17P: Wet Pond Hydrograph 230 --Izpp.�3 _______ T__JI__Jr__T__T--- Ir__ T__ T__ �___-___ T__T___II___ r__T__ I 1 0Pnmary 220 210 ,, __7__ _r__r__-_____r__7__-___r_l�QQe_a�ri_ 200 ,80 ,',' 1 $tgtag�a$8;53rg -qf= 160 ' 1I2.95 150 _ ch 1 __ _L__A__ 1 1 1 1 1 140 ,� � — - 1 _r -r _, -I -r _, -r -I -r _, -1 -r--r -, -I 130 ___ 120 c 1101 --�i 1 1 --- r--r__1__r-----r--,---r--r--r--r---r--r--r-- LL ,00 9O i'i -1 1 1 1 -I- -♦ -Y -I -r -Y -Y -I -Y -, -I -F -♦ -7 -I -Y -Y 80 70 60 -r--r--___r--r__r--r---r--r-----r--r--r--r---r--r--r-- 50 1 1 30 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Link 8L: Total to Pond Inflow Area = 20.268 ac, 57.09% Impervious, Inflow Depth = 6.57" for 100-Year event Inflow = 209.13 cfs @ 12.00 hrs, Volume= 11.092 of Primary = 209.13 cfs @ 12.00 hrs, Volume= 11.092 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 8L: Total to Pond Hydrograph ■Inflow 230 -- 208.13 cfs �___1___r__r__r__ ■Pnmary 229.,3�- --------------- I`-I--JI ---'I Inflow Area=20.268ac: 210 -- ----r --,---r--r----,-- 200 --=---------- -- ---I so , 1 1 1 1 I 1 1 1 1so-r--r--,---1---r--,--,---1---r--�---I---r--,--,---1---r--,-- 150 .' _I___L__-- 1--_1___ ii1i 1JL__ L__J___1___ L__ 1__ 1 1 1 1 1 1 1 1 1 1 1 140 ,� I ------------------ 130 ," p 110 , "' " --�i 1 1 1 -r--r_____r--r__1__r-----r--,---r--r--r--r---r--r--r-- LL 100 � 1 L 1 L ' 90 .' __, 1 1 1 1 1 1 1 1 1 1 1 1 _-__r__y___1___r__7__y___1___r__-___I___r__T__y___1___r__Y__ 80 " '" _ 1 1 1 1 1 1 1 60 -- 1 1 1 --r-----1-rrr--- rr,--- --- r--r--- 1--- r--7-- 50 1 40 __* _'____---r-------- --r-------r--*_---r--�-- 0 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Link 14L: Total to Outfall 1 Inflow Area = 20.857 ac, 55.56% Impervious, Inflow Depth > 6.42" for 100-Year event Inflow = 144.45 cfs @ 12.07 hrs, Volume= 11.158 of Primary = 144.45 cfs @ 12.07 hrs, Volume= 11.158 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 14L: Total to Outfall 1 Hydrograph 180 /' -- -- - ------ -- -- ------ --,-- -- 150 1".<5d( - - -II r--,I---1,--(01---- re 0. 140 I I I I I 1S0 I I I I I 120 I I I I I I I I I I I I I I I I 1 110 / 1 100 1 90 r r r r u _ 3 80 ' I 1 Q _1 _I LL 70 , I I I I I 1 60 I I I I I I I I I I I I 50 1 I I I Qp / I I I I I I I I I I I I I 1 30 1 20 -----1---1--7---1---1-- 10 ' 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) ■ Inflow ■ Primary POST DEV Prepared by Timmons Type/1 24-hr 100-Year Rainfall=9.09" Printed 5/6/2022 Summary for Link 15L: Total to Outfall 2 Inflow Area = 1.935 ac, 36.59% Impervious, Inflow Depth = 5.99" for 100-Year event Inflow = 24.65 cfs @ 12.05 hrs, Volume= 0.966 of Primary = 24.65 cfs @ 12.05 hrs, Volume= 0.966 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-100.00 hrs, dt= 0.05 hrs Link 15L: Total to Outfall 2 Hydrograph __---I---I---i-- ,___r_____r___r__r__,_ ❑Inflow II ❑Primary 26 24____-- --fovArea-1,935ac_ -iII 24 I I II II II Ir 22 II II II 20 r___rI___r_r_7____r_I____r_r___I I I I I I I J__J___L__ 18 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 16 " 14- T---I---r--r--r--r__r__r---r--r--�---I---r--r---I---r-_ p i I ILL 12 I I I I- I I I- r I I I I I I I I I I I I I I I I I , ' I I I I I I 8 I I I I I I I I I I I I I I I I I I I I I I I I I I I 6 .rr___ r__r__1___I___r__r___I___r__ 45 50 55 60 65 70 75 80 85 90 95 1 Time (hours) CAN11 Chesapeake Bay Nutrient Land Trust, LLC. January 7, 2022 Timmons Group ATTN: Jessica Denko, P.E. 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 "Tomorrow's Natural Resources Today" RE: CBNLT/Reynolds Farm Nutrient Facility — Nutrient Credit Availability Project Reference: Rio Point, Albemarle County Dear Ms. Denko, This letter is to confirm the availability of authorized nutrient credits sufficient to meet your project requirements at our Reynolds Farm 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 Reynolds Farm Nutrient Reduction Implementation Plan dated October 16, 2019 which was authorized by VADEQ on December 1, 2020. The Reynolds Farm project has been authorized to provide nutrient credits for use in the James River watershed including HUCs 02080201, 02080202, 02080203, 02080204, 02080205 and 02080207. 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 the Reynolds Farm facility has 133.11 pounds of phosphorus credits available and will be able to meet the phosphorus removal requirement for your project. 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. Reed Vice President Chesapeake Bay Nutrient Land Trust, LLC. • 5735 S. Laburnum Avenue • Richmond, VA 23231 • P: 804.222.5114 • www.cbnit.com