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-2-U Open Space C Hyd. No. 38 Hydrograph Type = NRCS Runoff Peak Flow = 0.825 cfs Storm Frequency = 2-yr Time to Peak = 12.25 hrs Time Interval = 1 min Runoff Volume = 3,742 cuft Drainage Area = 0.86 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.825 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-2-U Woods C Hyd. No. 39 Hydrograph Type = NRCS Runoff Peak Flow = 0.711 cfs Storm Frequency = 2-yr Time to Peak = 12.25 hrs Time Interval = 1 min Runoff Volume = 3,353 cuft Drainage Area = 0.95 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.711 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-2-U Gravel C Hyd. No. 40 Hydrograph Type = NRCS Runoff Peak Flow = 0.220 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 695 cuft Drainage Area = 0.08 ac Curve Number = 89.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.220 cfs 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 Q (cfs) 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 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-2-U Impervious Hyd. No. 41 Hydrograph Type = NRCS Runoff Peak Flow = 3.541 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 12,682 cuft Drainage Area = 1.05 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 3.46 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.541 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-2-U Hyd. No. 42 Hydrograph Type = Junction Peak Flow = 4.824 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 20,472 cuft Inflow Hydrographs = 38, 39, 40, 41 Total Contrib. Area = 2.94 ac Qp = 4.824 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-2-U Open Space C EX-2-U Woods C EX-2-U Gravel C EX-2-U Impervious EX-2-U

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Open Space C Hyd. No. 38 Hydrograph Type = NRCS Runoff Peak Flow = 1.876 cfs Storm Frequency = 10-yr Time to Peak = 12.23 hrs Time Interval = 1 min Runoff Volume = 8,243 cuft Drainage Area = 0.86 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.876 cfs 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 Q (cfs) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 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-2-U Woods C Hyd. No. 39 Hydrograph Type = NRCS Runoff Peak Flow = 1.788 cfs Storm Frequency = 10-yr Time to Peak = 12.23 hrs Time Interval = 1 min Runoff Volume = 7,917 cuft Drainage Area = 0.95 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.788 cfs 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 Q (cfs) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 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-2-U Gravel C Hyd. No. 40 Hydrograph Type = NRCS Runoff Peak Flow = 0.379 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 1,239 cuft Drainage Area = 0.08 ac Curve Number = 89.00 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 = 0.379 cfs 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 Q (cfs) 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-2-U Impervious Hyd. No. 41 Hydrograph Type = NRCS Runoff Peak Flow = 5.540 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 20,214 cuft Drainage Area = 1.05 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 = 5.540 cfs 6 5 4 Q (cfs) 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Hyd. No. 42 Hydrograph Type = Junction Peak Flow = 8.660 cfs Storm Frequency = 10-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 37,613 cuft Inflow Hydrographs = 38, 39, 40, 41 Total Contrib. Area = 2.94 ac Qp = 8.660 cfs 9 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-U Open Space C EX-2-U Woods C EX-2-U Gravel C EX-2-U Impervious EX-2-U