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 EX-1-D Impervious Hyd. No. 3 Hydrograph Type = NRCS Runoff Peak Flow = 0.475 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 1,733 cuft Drainage Area = 0.09 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.475 cfs 0.48 0.46 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 Q (cfs) 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Hyd. No. 4 Hydrograph Type = Junction Peak Flow = 4.218 cfs Storm Frequency = 10-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 17,682 cuft Inflow Hydrographs = 1, 2, 3 Total Contrib. Area = 1.52 ac Qp = 4.218 cfs 5 4 3 Q (cfs) 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-1-D Open Space D EX-1-D Woods D EX-1-D Impervious EX-1-D

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 3.834 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 16,035 cuft Drainage Area = 0.65 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.834 cfs 4 3 Q (cfs) 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Woods D Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 4.396 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 18,185 cuft Drainage Area = 0.78 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 4.396 cfs 5 4 3 Q (cfs) 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Impervious Hyd. No. 3 Hydrograph Type = NRCS Runoff Peak Flow = 0.818 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 3,032 cuft Drainage Area = 0.09 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.818 cfs 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 Q (cfs) 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Hyd. No. 4 Hydrograph Type = Junction Peak Flow = 8.751 cfs Storm Frequency = 100-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 37,253 cuft Inflow Hydrographs = 1, 2, 3 Total Contrib. Area = 1.52 ac Qp = 8.751 cfs 10 9 8 7 6 Q (cfs) 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-1-D Open Space D EX-1-D Woods D EX-1-D Impervious EX-1-D

= = EX-1-DISTURBED WATERSHED ALLOWABLE PEAK DISCHARGE

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D 2 YR ALLOW Hyd. No. 6 Hydrograph Type = Diversion Peak Flow = 1.039 cfs Storm Frequency = 2-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 4,420 cuft Inflow Hydrograph = 4 - EX-1-D Diversion Method = Flow Ratio Companion Hyd = 7 - <name> Flow Ratio = 0.5 Qp = 1.039 cfs 3 2 Q (cfs) 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-1-D EX-1-D 2 YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D 10 YR ALLOW Hyd. No. 8 Hydrograph Type = Diversion Peak Flow = 3.163 cfs Storm Frequency = 10-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 13,261 cuft Inflow Hydrograph = 4 - EX-1-D Diversion Method = Flow Ratio Companion Hyd = 9 - <name> Flow Ratio = 0.75 Qp = 3.163 cfs 5 4 3 Q (cfs) 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-1-D EX-1-D 10 YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D 100 YR ALLOW Hyd. No. 10 Hydrograph Type = Diversion Peak Flow = 7.001 cfs Storm Frequency = 100-yr Time to Peak = 12.18 hrs Time Interval = 1 min Hydrograph Volume = 29,802 cuft Inflow Hydrograph = 4 - EX-1-D Diversion Method = Flow Ratio Companion Hyd = 11 - <name> Flow Ratio = 0.8 Qp = 7.001 cfs 10 9 8 7 6 Q (cfs) 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-1-D EX-1-D 100 YR ALLOW