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

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Hyd. No. 30 Hydrograph Type = Junction Peak Flow = 10.33 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 41,818 cuft Inflow Hydrographs = 25, 26, 27, 28 Total Contrib. Area = 2.41 ac Qp = 10.33 cfs 11 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-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 (Future).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 = 3.174 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 13,483 cuft Drainage Area = 0.41 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.174 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 (Future).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 = 7.636 cfs Storm Frequency = 100-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 32,040 cuft Drainage Area = 1.02 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 7.636 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)

Hydrograph Report File: Eagle Rock Existing (Future).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 = 0.820 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 2,666 cuft Drainage Area = 0.07 ac Curve Number = 91.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.820 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 (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Impervious Hyd. No. 28 Hydrograph Type = NRCS Runoff Peak Flow = 10.88 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 37,521 cuft Drainage Area = 0.91 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 10.88 cfs 12 11 10 9 8 7 Q (cfs) 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)

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D Hyd. No. 30 Hydrograph Type = Junction Peak Flow = 20.54 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 85,710 cuft Inflow Hydrographs = 25, 26, 27, 28 Total Contrib. Area = 2.41 ac Qp = 20.54 cfs 23 22 21 20 19 18 17 16 15 14 13 12 Q (cfs) 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 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

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D 2 YR ALLOW Hyd. No. 31 Hydrograph Type = Diversion Peak Flow = 2.974 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 11,783 cuft Inflow Hydrograph = 30 - EX-2-D Diversion Method = Flow Ratio Companion Hyd = 32 - <name> Flow Ratio = 0.5 Qp = 2.974 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) EX-2-D EX-2-D 2 YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D 10 YR ALLOW Hyd. No. 33 Hydrograph Type = Diversion Peak Flow = 7.745 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 31,364 cuft Inflow Hydrograph = 30 - EX-2-D Diversion Method = Flow Ratio Companion Hyd = 34 - <name> Flow Ratio = 0.75 Qp = 7.745 cfs 11 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-2-D EX-2-D 10 YR ALLOW

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-D 100 YR ALLOW Hyd. No. 35 Hydrograph Type = Diversion Peak Flow = 16.43 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 68,568 cuft Inflow Hydrograph = 30 - EX-2-D Diversion Method = Flow Ratio Companion Hyd = 36 - <name> Flow Ratio = 0.8 Qp = 16.43 cfs 23 22 21 20 19 18 17 16 15 14 13 12 Q (cfs) 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 EX-2-D 100 YR ALLOW