2026 02 12 Crestmont CC and Eagle Rock Ave Stormwater Management Report

Hydrograph 25-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 1 NRCS Runoff PR-1A-D Grass D 1.994 12.13 6,712 ---- 2 NRCS Runoff PR-1A-D Imp 2.562 12.10 8,592 ---- 3 Junction PR-1A-D 4.475 12.10 15,305 1, 2 5 NRCS Runoff PR-1A-U Open Space C 1.649 12.17 6,148 ---- 6 NRCS Runoff PR-1A-U Woods C 0.365 12.17 1,353 ---- 7 NRCS Runoff PR-1A-U Imp 4.003 12.10 13,426 ---- 8 Junction PR-1A-U 5.721 12.10 20,926 5, 6, 7 10 Junction PR-1A Total 10.20 12.10 36,231 3, 8 11 Pond Route PR-1A Routing 4.639 12.23 33,331 10 536.30 11,447 13 NRCS Runoff PR-1B-D 2.356 12.12 7,530 ---- 15 NRCS Runoff PR-1B-U Open Space C 1.349 12.18 5,225 ---- 16 NRCS Runoff PR-1B-U Woods C 2.633 12.18 10,138 ---- 17 NRCS Runoff PR-1B-U Impervious 8.489 12.12 32,952 ---- 18 Junction PR-1B-U 12.19 12.13 48,315 15, 16, 17 21 Junction PR-1B (Swale) 14.48 12.13 55,845 13, 18 24 NRCS Runoff PR-1C-D Open Space D 2.185 12.10 6,258 ---- 25 NRCS Runoff PR-1C-D Impervious 0.881 12.10 2,954 ---- 26 Junction PR-1C-D

-D Open Space D 2.185 12.10 6,258 ---- 25 NRCS Runoff PR-1C-D Impervious 0.881 12.10 2,954 ---- 26 Junction PR-1C-D 3.065 12.10 9,212 24, 25 28 NRCS Runoff PR-1C-U Open Space C 3.804 12.15 13,361 ---- 29 NRCS Runoff PR-1C-U Impervious 9.371 12.10 32,078 ---- 30 Junction PR-1C-U 12.81 12.10 45,439 28, 29 32 Junction POA-1 33.09 12.12 143,827 11, 21, 26, 30 35 NRCS Runoff PR-2A-D Open Space D 5.384 12.12 17,211 ---- 36 NRCS Runoff PR-2A-D Impervious 3.362 12.10 11,277 ----

Hydrograph 25-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 37 Junction PR-2A-D 8.643 12.10 28,488 35, 36 39 NRCS Runoff PR-2A-U Open Space C 0.808 12.20 3,295 ---- 40 NRCS Runoff PR-2A-U Woods C 0.737 12.20 2,990 ---- 41 NRCS Runoff PR-2A-U Impervious 5.444 12.10 18,259 ---- 42 Junction PR-2A-U 6.642 12.10 24,543 39, 40, 41 45 Junction PR-2A 15.28 12.10 53,032 37, 42 46 Pond Route PR-2A Routing 6.082 12.25 49,644 45 539.07 19,070 48 NRCS Runoff PR-2B-D Open Space D 0.212 12.10 626 ---- 49 NRCS Runoff PR-2B-D Impervious 2.962 12.10 9,935 ---- 50 Junction PR-2B-D 3.174 12.10 10,561 48, 49 52 NRCS Runoff PR-2B-U Open Space C 0.062 12.10 172 ---- 53 NRCS Runoff PR-2B-U Impervious 0.240 12.10 806 ---- 54 Junction PR-2B-U 0.302 12.10 977 52, 53 56 Junction PR-2B 3.476 12.10 11,538 50, 54 57 Pond Route PR-2B Routing 0.354 12.85 11,525 56 554.92 5,060 59 NRCS Runoff PR-2C-D Open Space D 3.960 12.10 11,343 ---- 60 NRCS Runoff PR-2C-D Impervious 2.322 12.10 7,787 ---- 61

59 NRCS Runoff PR-2C-D Open Space D 3.960 12.10 11,343 ---- 60 NRCS Runoff PR-2C-D Impervious 2.322 12.10 7,787 ---- 61 Junction PR-2C-D 6.281 12.10 19,130 59, 60 63 NRCS Runoff PR-2C-U Open Space C 3.052 12.20 12,446 ---- 64 NRCS Runoff PR-2C-U Woods C 3.154 12.20 12,791 ---- 65 NRCS Runoff PR-2C-U Gravel C 0.609 12.10 1,855 ---- 66 NRCS Runoff PR-2C-U Impervious 3.843 12.10 12,889 ---- 67 Junction PR-2C-U 9.262 12.10 39,981 63, 64, 65, 66 70 Junction POA-2 20.85 12.10 120,279 46, 57, 61, 67

Hydrograph 100-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 1 NRCS Runoff PR-1A-D Grass D 3.062 12.13 10,581 ---- 2 NRCS Runoff PR-1A-D Imp 3.659 12.10 12,370 ---- 3 Junction PR-1A-D 6.611 12.10 22,951 1, 2 5 NRCS Runoff PR-1A-U Open Space C 2.644 12.17 10,047 ---- 6 NRCS Runoff PR-1A-U Woods C 0.604 12.17 2,270 ---- 7 NRCS Runoff PR-1A-U Imp 5.717 12.10 19,327 ---- 8 Junction PR-1A-U 8.523 12.10 31,645 5, 6, 7 10 Junction PR-1A Total 15.13 12.10 54,595 3, 8 11 Pond Route PR-1A Routing 10.05 12.15 51,696 10 536.73 13,696 13 NRCS Runoff PR-1B-D 3.616 12.12 11,870 ---- 15 NRCS Runoff PR-1B-U Open Space C 2.163 12.18 8,539 ---- 16 NRCS Runoff PR-1B-U Woods C 4.359 12.18 17,013 ---- 17 NRCS Runoff PR-1B-U Impervious 12.13 12.12 47,437 ---- 18 Junction PR-1B-U 18.24 12.13 72,989 15, 16, 17 21 Junction PR-1B (Swale) 21.76 12.13 84,859 13, 18 24 NRCS Runoff PR-1C-D Open Space D 3.337 12.10 9,866 ---- 25 NRCS Runoff PR-1C-D Impervious 1.258 12.10 4,252 ---- 26 Junction PR-1C-D

-D Open Space D 3.337 12.10 9,866 ---- 25 NRCS Runoff PR-1C-D Impervious 1.258 12.10 4,252 ---- 26 Junction PR-1C-D 4.595 12.10 14,118 24, 25 28 NRCS Runoff PR-1C-U Open Space C 6.092 12.15 21,836 ---- 29 NRCS Runoff PR-1C-U Impervious 13.38 12.10 46,180 ---- 30 Junction PR-1C-U 18.95 12.10 68,016 28, 29 32 Junction POA-1 53.61 12.12 218,689 11, 21, 26, 30 35 NRCS Runoff PR-2A-D Open Space D 8.266 12.12 27,131 ---- 36 NRCS Runoff PR-2A-D Impervious 4.802 12.10 16,235 ----

Hydrograph 100-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (hrs) (cuft) (ft) (cuft) 37 Junction PR-2A-D 12.93 12.10 43,366 35, 36 39 NRCS Runoff PR-2A-U Open Space C 1.297 12.20 5,384 ---- 40 NRCS Runoff PR-2A-U Woods C 1.222 12.20 5,018 ---- 41 NRCS Runoff PR-2A-U Impervious 7.775 12.10 26,285 ---- 42 Junction PR-2A-U 9.764 12.10 36,687 39, 40, 41 45 Junction PR-2A 22.69 12.10 80,053 37, 42 46 Pond Route PR-2A Routing 9.295 12.23 76,666 45 539.63 25,429 48 NRCS Runoff PR-2B-D Open Space D 0.325 12.10 987 ---- 49 NRCS Runoff PR-2B-D Impervious 4.230 12.10 14,302 ---- 50 Junction PR-2B-D 4.555 12.10 15,289 48, 49 52 NRCS Runoff PR-2B-U Open Space C 0.098 12.10 280 ---- 53 NRCS Runoff PR-2B-U Impervious 0.343 12.10 1,160 ---- 54 Junction PR-2B-U 0.441 12.10 1,440 52, 53 56 Junction PR-2B 4.996 12.10 16,729 50, 54 57 Pond Route PR-2B Routing 0.641 12.62 16,716 56 555.69 7,083 59 NRCS Runoff PR-2C-D Open Space D 6.049 12.10 17,882 ---- 60 NRCS Runoff PR-2C-D Impervious 3.316 12.10 11,210 ---- 61

59 NRCS Runoff PR-2C-D Open Space D 6.049 12.10 17,882 ---- 60 NRCS Runoff PR-2C-D Impervious 3.316 12.10 11,210 ---- 61 Junction PR-2C-D 9.365 12.10 29,092 59, 60 63 NRCS Runoff PR-2C-U Open Space C 4.898 12.20 20,341 ---- 64 NRCS Runoff PR-2C-U Woods C 5.226 12.20 21,464 ---- 65 NRCS Runoff PR-2C-U Gravel C 0.890 12.10 2,787 ---- 66 NRCS Runoff PR-2C-U Impervious 5.488 12.10 18,554 ---- 67 Junction PR-2C-U 14.37 12.10 63,147 63, 64, 65, 66 70 Junction POA-2 31.63 12.10 185,620 46, 57, 61, 67

APPENDIX C Pond Routing Calculations

= = APPENDIX C TABLE OF CONTENTS CURRENT POND ROUTING CALCULATIONS PR-1A WATERSHED POND ROUTING Small-Scale Bioretention Basin Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event PR-2A WATERSHED POND ROUTING Small-Scale Bioretention Basin Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event PR-2B WATERSHED POND ROUTING Porous Asphalt Pavement System Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event FUTURE POND ROUTING CALCULATIONS PR-1A WATERSHED POND ROUTING Small-Scale Bioretention Basin Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event PR-2A WATERSHED POND ROUTING Small-Scale Bioretention Basin Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event PR-2B WATERSHED POND ROUTING Porous Asphalt Pavement System Pond Report 2 Year Design Storm Event 10 Year Design Storm Event 25 Year Design Storm Event 100 Year Design Storm Event