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

SUMMARY OF EXISTING PEAK DISCHARGES

Hydrograph 2-yr Summary File: Eagle Rock Existing (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 EX-1-D Open Space D 1.274 12.18 4,896 ---- 2 NRCS Runoff EX-1-D Woods D 1.356 12.18 5,225 ---- 3 NRCS Runoff EX-1-D Impervious 0.359 12.12 1,295 ---- 4 Junction EX-1-D 2.885 12.17 11,416 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 1.443 12.17 5,708 4 7 Diversion2 <name> 1.443 12.17 5,708 4 8 Diversion1 EX-1-D 10 YR ALLOW 2.164 12.17 8,562 4 9 Diversion2 <name> 0.721 12.17 2,854 4 10 Diversion1 EX-1-D 100 YR ALLOW 2.308 12.17 9,133 4 11 Diversion2 <name> 0.577 12.17 2,283 4 13 NRCS Runoff EX-1-U Open Space C 2.070 12.18 8,044 ---- 14 NRCS Runoff EX-1-U Woods C 0.871 12.18 3,460 ---- 15 NRCS Runoff EX-1-U Impervious 11.73 12.12 42,316 ---- 16 Junction EX-1-U 14.21 12.12 53,820 13, 14, 15 18 Junction TOTAL POA-1 16.83 12.12 65,237 4, 16 19 Junction POA-1 2 yr Allow 15.52 12.12 59,528 6, 16 20 Junction POA-1 10 yr Allow 16.18 12.12 62,383 8, 16 21 Junction POA-1 100yr Allow 16.31 12.12 62,953 10, 16 25 NRCS

Junction POA-1 10 yr Allow 16.18 12.12 62,383 8, 16 21 Junction POA-1 100yr Allow 16.31 12.12 62,953 10, 16 25 NRCS Runoff EX-2-D Open Space D 0.774 12.20 3,137 ---- 26 NRCS Runoff EX-2-D Woods D 1.707 12.20 6,941 ---- 27 NRCS Runoff EX-2-D Gravel D 0.261 12.10 786 ---- 28 NRCS Runoff EX-2-D Impervious 3.799 12.10 12,701 ---- 30 Junction EX-2-D 5.948 12.12 23,566 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 2.974 12.12 11,783 30 32 Diversion2 <name> 2.974 12.12 11,783 30 33 Diversion1 EX-2-D 10 YR ALLOW 4.461 12.12 17,674 30 34 Diversion2 <name> 1.487 12.12 5,891 30 35 Diversion1 EX-2-D 100 YR ALLOW 4.758 12.12 18,852 30 36 Diversion2 <name> 1.190 12.12 4,713 30

Hydrograph 2-yr Summary File: Eagle Rock Existing (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) 38 NRCS Runoff EX-2-U Open Space C 1.147 12.23 5,109 ---- 39 NRCS Runoff EX-2-U Woods C 1.035 12.25 4,716 ---- 40 NRCS Runoff EX-2-U Gravel C 0.271 12.12 868 ---- 41 NRCS Runoff EX-2-U Impervious 4.188 12.12 15,113 ---- 42 Junction EX-2-U 6.021 12.12 25,806 38, 39, 40, 41 44 Junction TOTAL POA-2 11.97 12.12 49,371 30, 42 45 Junction POA-2 2YR ALLOW 8.995 12.12 37,589 31, 42 46 Junction POA-2 10YR ALLOW 10.48 12.12 43,480 33, 42 47 Junction POA-2 100YR ALLOW 10.78 12.12 44,658 35, 42

Hydrograph 10-yr Summary File: Eagle Rock Existing (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 EX-1-D Open Space D 2.457 12.18 9,562 ---- 2 NRCS Runoff EX-1-D Woods D 2.745 12.18 10,603 ---- 3 NRCS Runoff EX-1-D Impervious 0.563 12.12 2,066 ---- 4 Junction EX-1-D 5.617 12.17 22,230 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 2.809 12.17 11,115 4 7 Diversion2 <name> 2.809 12.17 11,115 4 8 Diversion1 EX-1-D 10 YR ALLOW 4.213 12.17 16,673 4 9 Diversion2 <name> 1.404 12.17 5,558 4 10 Diversion1 EX-1-D 100 YR ALLOW 4.494 12.17 17,784 4 11 Diversion2 <name> 1.123 12.17 4,446 4 13 NRCS Runoff EX-1-U Open Space C 4.419 12.18 17,001 ---- 14 NRCS Runoff EX-1-U Woods C 2.017 12.18 7,758 ---- 15 NRCS Runoff EX-1-U Impervious 18.39 12.12 67,481 ---- 16 Junction EX-1-U 23.98 12.12 92,240 13, 14, 15 18 Junction TOTAL POA-1 29.21 12.13 114,471 4, 16 19 Junction POA-1 2 yr Allow 26.56 12.12 103,356 6, 16 20 Junction POA-1 10 yr Allow 27.85 12.13 108,913 8, 16 21 Junction POA-1 100yr Allow 28.13 12.13 110,025 10, 16 25 NRCS

Junction POA-1 10 yr Allow 27.85 12.13 108,913 8, 16 21 Junction POA-1 100yr Allow 28.13 12.13 110,025 10, 16 25 NRCS Runoff EX-2-D Open Space D 1.496 12.20 6,127 ---- 26 NRCS Runoff EX-2-D Woods D 3.463 12.20 14,085 ---- 27 NRCS Runoff EX-2-D Gravel D 0.434 12.10 1,352 ---- 28 NRCS Runoff EX-2-D Impervious 5.958 12.10 20,254 ---- 30 Junction EX-2-D 10.33 12.12 41,818 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 5.163 12.12 20,909 30 32 Diversion2 <name> 5.163 12.12 20,909 30 33 Diversion1 EX-2-D 10 YR ALLOW 7.745 12.12 31,364 30 34 Diversion2 <name> 2.582 12.12 10,454 30 35 Diversion1 EX-2-D 100 YR ALLOW 8.262 12.12 33,454 30 36 Diversion2 <name> 2.065 12.12 8,364 30

Hydrograph 10-yr Summary File: Eagle Rock Existing (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) 38 NRCS Runoff EX-2-U Open Space C 2.460 12.23 10,797 ---- 39 NRCS Runoff EX-2-U Woods C 2.405 12.23 10,574 ---- 40 NRCS Runoff EX-2-U Gravel C 0.461 12.12 1,526 ---- 41 NRCS Runoff EX-2-U Impervious 6.568 12.12 24,100 ---- 42 Junction EX-2-U 10.74 12.13 46,998 38, 39, 40, 41 44 Junction TOTAL POA-2 21.02 12.12 88,816 30, 42 45 Junction POA-2 2YR ALLOW 15.86 12.12 67,907 31, 42 46 Junction POA-2 10YR ALLOW 18.44 12.12 78,361 33, 42 47 Junction POA-2 100YR ALLOW 18.96 12.12 80,452 35, 42

Hydrograph 100-yr Summary File: Eagle Rock Existing (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 EX-1-D Open Space D 5.206 12.17 21,042 ---- 2 NRCS Runoff EX-1-D Woods D 6.043 12.18 24,118 ---- 3 NRCS Runoff EX-1-D Impervious 1.028 12.12 3,827 ---- 4 Junction EX-1-D 12.04 12.17 48,987 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 6.021 12.17 24,494 4 7 Diversion2 <name> 6.021 12.17 24,494 4 8 Diversion1 EX-1-D 10 YR ALLOW 9.031 12.17 36,740 4 9 Diversion2 <name> 3.010 12.17 12,247 4 10 Diversion1 EX-1-D 100 YR ALLOW 9.633 12.17 39,190 4 11 Diversion2 <name> 2.408 12.17 9,797 4 13 NRCS Runoff EX-1-U Open Space C 10.14 12.18 40,046 ---- 14 NRCS Runoff EX-1-U Woods C 4.921 12.18 19,208 ---- 15 NRCS Runoff EX-1-U Impervious 33.57 12.12 125,010 ---- 16 Junction EX-1-U 46.96 12.12 184,264 13, 14, 15 18 Junction TOTAL POA-1 58.39 12.13 233,251 4, 16 19 Junction POA-1 2 yr Allow 52.56 12.13 208,758 6, 16 20 Junction POA-1 10 yr Allow 55.47 12.13 221,004 8, 16 21 Junction POA-1 100yr Allow 56.05 12.13 223,454 10, 16 25 NRCS

Junction POA-1 10 yr Allow 55.47 12.13 221,004 8, 16 21 Junction POA-1 100yr Allow 56.05 12.13 223,454 10, 16 25 NRCS Runoff EX-2-D Open Space D 3.174 12.20 13,483 ---- 26 NRCS Runoff EX-2-D Woods D 7.636 12.20 32,040 ---- 27 NRCS Runoff EX-2-D Gravel D 0.820 12.10 2,666 ---- 28 NRCS Runoff EX-2-D Impervious 10.88 12.10 37,521 ---- 30 Junction EX-2-D 20.54 12.12 85,710 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 10.27 12.12 42,855 30 32 Diversion2 <name> 10.27 12.12 42,855 30 33 Diversion1 EX-2-D 10 YR ALLOW 15.40 12.12 64,283 30 34 Diversion2 <name> 5.134 12.12 21,428 30 35 Diversion1 EX-2-D 100 YR ALLOW 16.43 12.12 68,568 30 36 Diversion2 <name> 4.107 12.12 17,142 30

Hydrograph 100-yr Summary File: Eagle Rock Existing (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) 38 NRCS Runoff EX-2-U Open Space C 5.666 12.23 25,433 ---- 39 NRCS Runoff EX-2-U Woods C 5.895 12.23 26,181 ---- 40 NRCS Runoff EX-2-U Gravel C 0.886 12.12 3,066 ---- 41 NRCS Runoff EX-2-U Impervious 11.99 12.12 44,646 ---- 42 Junction EX-2-U 22.11 12.13 99,326 38, 39, 40, 41 44 Junction TOTAL POA-2 42.47 12.12 185,037 30, 42 45 Junction POA-2 2YR ALLOW 32.20 12.12 142,182 31, 42 46 Junction POA-2 10YR ALLOW 37.33 12.12 163,609 33, 42 47 Junction POA-2 100YR ALLOW 38.36 12.12 167,894 35, 42