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-2C-U Impervious Hyd. No. 66 Hydrograph Type = NRCS Runoff Peak Flow = 3.174 cfs Storm Frequency = 25-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 10,587 cuft Drainage Area = 0.48 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 = 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Hyd. No. 67 Hydrograph Type = Junction Peak Flow = 6.937 cfs Storm Frequency = 25-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 31,147 cuft Inflow Hydrographs = 63, 64, 65, 66 Total Contrib. Area = 2.01 ac Qp = 6.937 cfs 7 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-2C-U Open Space C PR-2C-U Woods C PR-2C-U Gravel C PR-2C-U Impervious PR-2C-U

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Open Space C Hyd. No. 63 Hydrograph Type = NRCS Runoff Peak Flow = 3.514 cfs Storm Frequency = 100-yr Time to Peak = 12.22 hrs Time Interval = 1 min Runoff Volume = 15,116 cuft Drainage Area = 0.68 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 16.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.514 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Woods C Hyd. No. 64 Hydrograph Type = NRCS Runoff Peak Flow = 3.677 cfs Storm Frequency = 100-yr Time to Peak = 12.22 hrs Time Interval = 1 min Runoff Volume = 15,698 cuft Drainage Area = 0.77 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 16.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.677 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Gravel C Hyd. No. 65 Hydrograph Type = NRCS Runoff Peak Flow = 0.699 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 2,152 cuft Drainage Area = 0.08 ac Curve Number = 89.00 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 = 0.699 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Impervious Hyd. No. 66 Hydrograph Type = NRCS Runoff Peak Flow = 4.369 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 14,701 cuft Drainage Area = 0.48 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 = 4.369 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 Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2C-U Hyd. No. 67 Hydrograph Type = Junction Peak Flow = 10.44 cfs Storm Frequency = 100-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 47,667 cuft Inflow Hydrographs = 63, 64, 65, 66 Total Contrib. Area = 2.01 ac Qp = 10.44 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) PR-2C-U Open Space C PR-2C-U Woods C PR-2C-U Gravel C PR-2C-U Impervious PR-2C-U

TOTAL PROPOSED FLOW TO POA-2

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 Hyd. No. 70 Hydrograph Type = Junction Peak Flow = 5.668 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 37,577 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 5.668 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 26 27 28 29 30 Time (hrs) PR-2A Routing PR-2B Routing PR-2C-D PR-2C-U POA-2

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 POA-2 Hyd. No. 70 Hydrograph Type = Junction Peak Flow = 10.31 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Hydrograph Volume = 70,401 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 10.31 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 26 27 28 29 30 Time (hrs) PR-2A Routing PR-2B Routing PR-2C-D PR-2C-U POA-2