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-D Woods D Hyd. No. 26 Hydrograph Type = NRCS Runoff Peak Flow = 2.690 cfs Storm Frequency = 10-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 10,900 cuft Drainage Area = 1.02 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 15.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.690 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Gravel D Hyd. No. 27 Hydrograph Type = NRCS Runoff Peak Flow = 0.360 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 1,106 cuft Drainage Area = 0.07 ac Curve Number = 91.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.360 cfs 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-D Impervious Hyd. No. 28 Hydrograph Type = NRCS Runoff Peak Flow = 5.026 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 16,988 cuft Drainage Area = 0.91 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 5.026 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-D Hyd. No. 30 Hydrograph Type = Junction Peak Flow = 8.415 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 33,796 cuft Inflow Hydrographs = 25, 26, 27, 28 Total Contrib. Area = 2.41 ac Qp = 8.415 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-D Open Space D EX-2-D Woods D EX-2-D Gravel D EX-2-D Impervious EX-2-D

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Open Space D Hyd. No. 25 Hydrograph Type = NRCS Runoff Peak Flow = 2.418 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 10,115 cuft Drainage Area = 0.41 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 15.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.418 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Woods D Hyd. No. 26 Hydrograph Type = NRCS Runoff Peak Flow = 5.749 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 23,781 cuft Drainage Area = 1.02 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 15.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 5.749 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-D Gravel D Hyd. No. 27 Hydrograph Type = NRCS Runoff Peak Flow = 0.647 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 2,071 cuft Drainage Area = 0.07 ac Curve Number = 91.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.647 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-D Impervious Hyd. No. 28 Hydrograph Type = NRCS Runoff Peak Flow = 8.657 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 29,728 cuft Drainage Area = 0.91 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 8.657 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)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Hyd. No. 30 Hydrograph Type = Junction Peak Flow = 15.92 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 65,695 cuft Inflow Hydrographs = 25, 26, 27, 28 Total Contrib. Area = 2.41 ac Qp = 15.92 cfs 18 17 16 15 14 13 12 11 10 Q (cfs) 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 Open Space D EX-2-D Woods D EX-2-D Gravel D EX-2-D Impervious EX-2-D

= = EX-2-DISTURBED WATERSHED ALLOWABLE PEAK DISCHARGE