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

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 2YR ALLOW Hyd. No. 45 Hydrograph Type = Junction Peak Flow = 7.225 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 29,907 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 7.225 cfs 8 7 6 5 Q (cfs) 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 Time (hrs) EX-2-D 2 YR ALLOW EX-2-U POA-2 2YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 10YR ALLOW Hyd. No. 46 Hydrograph Type = Junction Peak Flow = 14.95 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 62,960 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 14.95 cfs 17 16 15 14 13 12 11 10 9 Q (cfs) 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 Time (hrs) EX-2-D 10 YR ALLOW EX-2-U POA-2 10YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 100YR ALLOW Hyd. No. 47 Hydrograph Type = Junction Peak Flow = 29.56 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 127,875 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 29.56 cfs 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 Q (cfs) 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 Time (hrs) EX-2-D 100 YR ALLOW EX-2-U POA-2 100YR ALLOW

SUMMARY OF EXISTING PEAK DISCHARGES

Hydrograph 2-yr Summary File: Eagle Rock Existing (Current).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 0.932 12.20 3,786 ---- 2 NRCS Runoff EX-1-D Woods D 0.967 12.20 3,966 ---- 3 NRCS Runoff EX-1-D Impervious 0.304 12.12 1,087 ---- 4 Junction EX-1-D 2.078 12.18 8,840 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 1.039 12.18 4,420 4 7 Diversion2 <name> 1.039 12.18 4,420 4 8 Diversion1 EX-1-D 10 YR ALLOW 1.558 12.18 6,630 4 9 Diversion2 <name> 0.519 12.18 2,210 4 10 Diversion1 EX-1-D 100 YR ALLOW 1.662 12.18 7,072 4 11 Diversion2 <name> 0.416 12.18 1,768 4 13 NRCS Runoff EX-1-U Open Space C 1.491 12.18 5,892 ---- 14 NRCS Runoff EX-1-U Woods C 0.600 12.20 2,460 ---- 15 NRCS Runoff EX-1-U Impervious 9.916 12.12 35,511 ---- 16 Junction EX-1-U 11.65 12.12 43,863 13, 14, 15 18 Junction TOTAL POA-1 13.48 12.12 52,703 4, 16 19 Junction POA-1 2 yr Allow 12.57 12.12 48,283 6, 16 20 Junction POA-1 10 yr Allow 13.02 12.12 50,493 8, 16 21 Junction POA-1 100yr Allow 13.12 12.12 50,935 10, 16 25 NRCS

Junction POA-1 10 yr Allow 13.02 12.12 50,493 8, 16 21 Junction POA-1 100yr Allow 13.12 12.12 50,935 10, 16 25 NRCS Runoff EX-2-D Open Space D 0.588 12.20 2,388 ---- 26 NRCS Runoff EX-2-D Woods D 1.264 12.20 5,187 ---- 27 NRCS Runoff EX-2-D Gravel D 0.214 12.10 636 ---- 28 NRCS Runoff EX-2-D Impervious 3.213 12.10 10,658 ---- 30 Junction EX-2-D 4.802 12.12 18,870 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 2.401 12.12 9,435 30 32 Diversion2 <name> 2.401 12.12 9,435 30 33 Diversion1 EX-2-D 10 YR ALLOW 3.601 12.12 14,152 30 34 Diversion2 <name> 1.200 12.12 4,717 30 35 Diversion1 EX-2-D 100 YR ALLOW 3.841 12.12 15,096 30 36 Diversion2 <name> 0.960 12.12 3,774 30

Hydrograph 2-yr Summary File: Eagle Rock Existing (Current).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 0.825 12.25 3,742 ---- 39 NRCS Runoff EX-2-U Woods C 0.711 12.25 3,353 ---- 40 NRCS Runoff EX-2-U Gravel C 0.220 12.12 695 ---- 41 NRCS Runoff EX-2-U Impervious 3.541 12.12 12,682 ---- 42 Junction EX-2-U 4.824 12.12 20,472 38, 39, 40, 41 44 Junction TOTAL POA-2 9.625 12.12 39,342 30, 42 45 Junction POA-2 2YR ALLOW 7.225 12.12 29,907 31, 42 46 Junction POA-2 10YR ALLOW 8.425 12.12 34,624 33, 42 47 Junction POA-2 100YR ALLOW 8.665 12.12 35,568 35, 42

Hydrograph 10-yr Summary File: Eagle Rock Existing (Current).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 1.871 12.20 7,614 ---- 2 NRCS Runoff EX-1-D Woods D 2.057 12.20 8,335 ---- 3 NRCS Runoff EX-1-D Impervious 0.475 12.12 1,733 ---- 4 Junction EX-1-D 4.218 12.18 17,682 1, 2, 3 6 Diversion1 EX-1-D 2 YR ALLOW 2.109 12.18 8,841 4 7 Diversion2 <name> 2.109 12.18 8,841 4 8 Diversion1 EX-1-D 10 YR ALLOW 3.163 12.18 13,261 4 9 Diversion2 <name> 1.054 12.18 4,420 4 10 Diversion1 EX-1-D 100 YR ALLOW 3.374 12.18 14,146 4 11 Diversion2 <name> 0.844 12.18 3,536 4 13 NRCS Runoff EX-1-U Open Space C 3.376 12.18 12,980 ---- 14 NRCS Runoff EX-1-U Woods C 1.502 12.18 5,809 ---- 15 NRCS Runoff EX-1-U Impervious 15.51 12.12 56,598 ---- 16 Junction EX-1-U 19.71 12.12 75,387 13, 14, 15 18 Junction TOTAL POA-1 23.47 12.13 93,069 4, 16 19 Junction POA-1 2 yr Allow 21.58 12.12 84,228 6, 16 20 Junction POA-1 10 yr Allow 22.52 12.12 88,648 8, 16 21 Junction POA-1 100yr Allow 22.71 12.12 89,532 10, 16 25 NRCS

Junction POA-1 10 yr Allow 22.52 12.12 88,648 8, 16 21 Junction POA-1 100yr Allow 22.71 12.12 89,532 10, 16 25 NRCS Runoff EX-2-D Open Space D 1.180 12.20 4,803 ---- 26 NRCS Runoff EX-2-D Woods D 2.690 12.20 10,900 ---- 27 NRCS Runoff EX-2-D Gravel D 0.360 12.10 1,106 ---- 28 NRCS Runoff EX-2-D Impervious 5.026 12.10 16,988 ---- 30 Junction EX-2-D 8.415 12.12 33,796 25, 26, 27, 28 31 Diversion1 EX-2-D 2 YR ALLOW 4.208 12.12 16,898 30 32 Diversion2 <name> 4.208 12.12 16,898 30 33 Diversion1 EX-2-D 10 YR ALLOW 6.312 12.12 25,347 30 34 Diversion2 <name> 2.104 12.12 8,449 30 35 Diversion1 EX-2-D 100 YR ALLOW 6.732 12.12 27,037 30 36 Diversion2 <name> 1.683 12.12 6,759 30

Hydrograph 10-yr Summary File: Eagle Rock Existing (Current).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 1.876 12.23 8,243 ---- 39 NRCS Runoff EX-2-U Woods C 1.788 12.23 7,917 ---- 40 NRCS Runoff EX-2-U Gravel C 0.379 12.12 1,239 ---- 41 NRCS Runoff EX-2-U Impervious 5.540 12.12 20,214 ---- 42 Junction EX-2-U 8.660 12.13 37,613 38, 39, 40, 41 44 Junction TOTAL POA-2 17.05 12.12 71,409 30, 42 45 Junction POA-2 2YR ALLOW 12.85 12.12 54,511 31, 42 46 Junction POA-2 10YR ALLOW 14.95 12.12 62,960 33, 42 47 Junction POA-2 100YR ALLOW 15.37 12.12 64,650 35, 42