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

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Grass D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 1.147 cfs Storm Frequency = 10-yr Time to Peak = 12.13 hrs Time Interval = 1 min Runoff Volume = 3,769 cuft Drainage Area = 0.33 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 8.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.147 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Imp Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 1.691 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 5,600 cuft Drainage Area = 0.32 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 2.0 min Total Rainfall = 5.38 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.691 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Hyd. No. 3 Hydrograph Type = Junction Peak Flow = 2.783 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 9,369 cuft Inflow Hydrographs = 1, 2 Total Contrib. Area = 0.65 ac Qp = 2.783 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) PR-1A-D Grass D PR-1A-D Imp PR-1A-D

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Grass D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 1.559 cfs Storm Frequency = 25-yr Time to Peak = 12.13 hrs Time Interval = 1 min Runoff Volume = 5,182 cuft Drainage Area = 0.33 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 8.0 min Total Rainfall = 6.72 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.559 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Imp Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 2.116 cfs Storm Frequency = 25-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 7,058 cuft Drainage Area = 0.32 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 2.0 min Total Rainfall = 6.72 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.116 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Hyd. No. 3 Hydrograph Type = Junction Peak Flow = 3.607 cfs Storm Frequency = 25-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 12,240 cuft Inflow Hydrographs = 1, 2 Total Contrib. Area = 0.65 ac Qp = 3.607 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) PR-1A-D Grass D PR-1A-D Imp PR-1A-D

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Grass D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 2.337 cfs Storm Frequency = 100-yr Time to Peak = 12.13 hrs Time Interval = 1 min Runoff Volume = 7,937 cuft Drainage Area = 0.33 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 8.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.337 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Imp Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 2.913 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 9,800 cuft Drainage Area = 0.32 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 2.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.913 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A-D Hyd. No. 3 Hydrograph Type = Junction Peak Flow = 5.159 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 17,738 cuft Inflow Hydrographs = 1, 2 Total Contrib. Area = 0.65 ac Qp = 5.159 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) PR-1A-D Grass D PR-1A-D Imp PR-1A-D

PR-1A-UNDISTURBED WATERSHED