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

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 Hyd. No. 70 Hydrograph Type = Junction Peak Flow = 31.63 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 185,620 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 31.63 cfs 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 Q (cfs) 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hrs) PR-2A Routing PR-2B Routing PR-2C-D PR-2C-U POA-2

SUMMARY OF PROPOSED PEAK DISCHARGES

Hydrograph 2-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 0.756 12.13 2,462 ---- 2 NRCS Runoff PR-1A-D Imp 1.279 12.10 4,187 ---- 3 Junction PR-1A-D 1.993 12.10 6,649 1, 2 5 NRCS Runoff PR-1A-U Open Space C 0.540 12.17 2,018 ---- 6 NRCS Runoff PR-1A-U Woods C 0.107 12.17 409 ---- 7 NRCS Runoff PR-1A-U Imp 1.998 12.10 6,542 ---- 8 Junction PR-1A-U 2.527 12.10 8,970 5, 6, 7 10 Junction PR-1A Total 4.520 12.10 15,619 3, 8 11 Pond Route PR-1A Routing 1.262 12.33 12,719 10 535.39 6,769 13 NRCS Runoff PR-1B-D 0.893 12.12 2,762 ---- 15 NRCS Runoff PR-1B-U Open Space C 0.441 12.18 1,715 ---- 16 NRCS Runoff PR-1B-U Woods C 0.772 12.18 3,065 ---- 17 NRCS Runoff PR-1B-U Impervious 4.234 12.12 16,058 ---- 18 Junction PR-1B-U 5.324 12.13 20,838 15, 16, 17 21 Junction PR-1B (Swale) 6.200 12.13 23,599 13, 18 24 NRCS Runoff PR-1C-D Open Space D 0.842 12.10 2,296 ---- 25 NRCS Runoff PR-1C-D Impervious 0.440 12.10 1,439 ---- 26 Junction PR-1C-D

D Open Space D 0.842 12.10 2,296 ---- 25 NRCS Runoff PR-1C-D Impervious 0.440 12.10 1,439 ---- 26 Junction PR-1C-D 1.282 12.10 3,735 24, 25 28 NRCS Runoff PR-1C-U Open Space C 1.251 12.15 4,386 ---- 29 NRCS Runoff PR-1C-U Impervious 4.676 12.10 15,632 ---- 30 Junction PR-1C-U 5.772 12.10 20,018 28, 29 32 Junction POA-1 14.07 12.12 60,072 11, 21, 26, 30 35 NRCS Runoff PR-2A-D Open Space D 2.042 12.12 6,313 ---- 36 NRCS Runoff PR-2A-D Impervious 1.679 12.10 5,496 ----

Hydrograph 2-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 3.665 12.10 11,808 35, 36 39 NRCS Runoff PR-2A-U Open Space C 0.264 12.20 1,082 ---- 40 NRCS Runoff PR-2A-U Woods C 0.215 12.22 904 ---- 41 NRCS Runoff PR-2A-U Impervious 2.718 12.10 8,898 ---- 42 Junction PR-2A-U 3.066 12.10 10,883 39, 40, 41 45 Junction PR-2A 6.730 12.10 22,691 37, 42 46 Pond Route PR-2A Routing 1.017 12.63 19,304 45 538.28 11,216 48 NRCS Runoff PR-2B-D Open Space D 0.081 12.10 230 ---- 49 NRCS Runoff PR-2B-D Impervious 1.479 12.10 4,841 ---- 50 Junction PR-2B-D 1.559 12.10 5,071 48, 49 52 NRCS Runoff PR-2B-U Open Space C 0.021 12.10 56.3 ---- 53 NRCS Runoff PR-2B-U Impervious 0.120 12.10 393 ---- 54 Junction PR-2B-U 0.141 12.10 449 52, 53 56 Junction PR-2B 1.700 12.10 5,520 50, 54 57 Pond Route PR-2B Routing 0.205 12.70 5,506 56 553.88 2,314 59 NRCS Runoff PR-2C-D Open Space D 1.526 12.10 4,161 ---- 60 NRCS Runoff PR-2C-D Impervious 1.159 12.10 3,795 ---- 61

59 NRCS Runoff PR-2C-D Open Space D 1.526 12.10 4,161 ---- 60 NRCS Runoff PR-2C-D Impervious 1.159 12.10 3,795 ---- 61 Junction PR-2C-D 2.685 12.10 7,955 59, 60 63 NRCS Runoff PR-2C-U Open Space C 0.996 12.20 4,086 ---- 64 NRCS Runoff PR-2C-U Woods C 0.921 12.22 3,867 ---- 65 NRCS Runoff PR-2C-U Gravel C 0.275 12.10 789 ---- 66 NRCS Runoff PR-2C-U Impervious 1.918 12.10 6,281 ---- 67 Junction PR-2C-U 3.584 12.10 15,022 63, 64, 65, 66 70 Junction POA-2 7.270 12.10 47,788 46, 57, 61, 67

Hydrograph 10-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 1.451 12.13 4,808 ---- 2 NRCS Runoff PR-1A-D Imp 2.005 12.10 6,677 ---- 3 Junction PR-1A-D 3.391 12.10 11,485 1, 2 5 NRCS Runoff PR-1A-U Open Space C 1.152 12.17 4,266 ---- 6 NRCS Runoff PR-1A-U Woods C 0.248 12.17 917 ---- 7 NRCS Runoff PR-1A-U Imp 3.133 12.10 10,433 ---- 8 Junction PR-1A-U 4.314 12.10 15,615 5, 6, 7 10 Junction PR-1A Total 7.705 12.10 27,101 3, 8 11 Pond Route PR-1A Routing 2.884 12.27 24,202 10 535.94 9,573 13 NRCS Runoff PR-1B-D 1.714 12.12 5,394 ---- 15 NRCS Runoff PR-1B-U Open Space C 0.942 12.18 3,625 ---- 16 NRCS Runoff PR-1B-U Woods C 1.787 12.18 6,871 ---- 17 NRCS Runoff PR-1B-U Impervious 6.642 12.12 25,607 ---- 18 Junction PR-1B-U 9.155 12.13 36,104 15, 16, 17 21 Junction PR-1B (Swale) 10.83 12.13 41,497 13, 18 24 NRCS Runoff PR-1C-D Open Space D 1.597 12.10 4,483 ---- 25 NRCS Runoff PR-1C-D Impervious 0.689 12.10 2,295 ---- 26 Junction PR-1C-D

D Open Space D 1.597 12.10 4,483 ---- 25 NRCS Runoff PR-1C-D Impervious 0.689 12.10 2,295 ---- 26 Junction PR-1C-D 2.286 12.10 6,778 24, 25 28 NRCS Runoff PR-1C-U Open Space C 2.662 12.15 9,270 ---- 29 NRCS Runoff PR-1C-U Impervious 7.333 12.10 24,928 ---- 30 Junction PR-1C-U 9.721 12.10 34,199 28, 29 32 Junction POA-1 24.77 12.12 106,676 11, 21, 26, 30 35 NRCS Runoff PR-2A-D Open Space D 3.918 12.12 12,329 ---- 36 NRCS Runoff PR-2A-D Impervious 2.631 12.10 8,764 ----

Hydrograph 10-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 6.465 12.10 21,092 35, 36 39 NRCS Runoff PR-2A-U Open Space C 0.564 12.20 2,286 ---- 40 NRCS Runoff PR-2A-U Woods C 0.500 12.20 2,027 ---- 41 NRCS Runoff PR-2A-U Impervious 4.260 12.10 14,189 ---- 42 Junction PR-2A-U 5.071 12.10 18,502 39, 40, 41 45 Junction PR-2A 11.54 12.10 39,594 37, 42 46 Pond Route PR-2A Routing 4.038 12.27 36,206 45 538.75 15,826 48 NRCS Runoff PR-2B-D Open Space D 0.154 12.10 448 ---- 49 NRCS Runoff PR-2B-D Impervious 2.318 12.10 7,720 ---- 50 Junction PR-2B-D 2.472 12.10 8,169 48, 49 52 NRCS Runoff PR-2B-U Open Space C 0.043 12.10 119 ---- 53 NRCS Runoff PR-2B-U Impervious 0.188 12.10 626 ---- 54 Junction PR-2B-U 0.231 12.10 745 52, 53 56 Junction PR-2B 2.704 12.10 8,914 50, 54 57 Pond Route PR-2B Routing 0.273 12.87 8,901 56 554.46 3,854 59 NRCS Runoff PR-2C-D Open Space D 2.895 12.10 8,126 ---- 60 NRCS Runoff PR-2C-D Impervious 1.817 12.10 6,051 ---- 61

59 NRCS Runoff PR-2C-D Open Space D 2.895 12.10 8,126 ---- 60 NRCS Runoff PR-2C-D Impervious 1.817 12.10 6,051 ---- 61 Junction PR-2C-D 4.712 12.10 14,177 59, 60 63 NRCS Runoff PR-2C-U Open Space C 2.131 12.20 8,635 ---- 64 NRCS Runoff PR-2C-U Woods C 2.138 12.20 8,669 ---- 65 NRCS Runoff PR-2C-U Gravel C 0.465 12.10 1,387 ---- 66 NRCS Runoff PR-2C-U Impervious 3.007 12.10 10,016 ---- 67 Junction PR-2C-U 6.724 12.10 28,708 63, 64, 65, 66 70 Junction POA-2 14.02 12.10 87,991 46, 57, 61, 67