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

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Woods C Hyd. No. 16 Hydrograph Type = NRCS Runoff Peak Flow = 2.633 cfs Storm Frequency = 25-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 10,138 cuft Drainage Area = 0.62 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 8.13 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.633 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 (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Impervious Hyd. No. 17 Hydrograph Type = NRCS Runoff Peak Flow = 8.489 cfs Storm Frequency = 25-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 32,952 cuft Drainage Area = 1.18 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 7.0 min Total Rainfall = 8.13 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 8.489 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 Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Hyd. No. 18 Hydrograph Type = Junction Peak Flow = 12.19 cfs Storm Frequency = 25-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 48,315 cuft Inflow Hydrographs = 15, 16, 17 Total Contrib. Area = 2.09 ac Qp = 12.19 cfs 14 13 12 11 10 9 8 Q (cfs) 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) PR-1B-U Open Space C PR-1B-U Woods C PR-1B-U Impervious PR-1B-U

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Open Space C Hyd. No. 15 Hydrograph Type = NRCS Runoff Peak Flow = 2.163 cfs Storm Frequency = 100-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 8,539 cuft Drainage Area = 0.29 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.163 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 (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Woods C Hyd. No. 16 Hydrograph Type = NRCS Runoff Peak Flow = 4.359 cfs Storm Frequency = 100-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 17,013 cuft Drainage Area = 0.62 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 4.359 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 (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Impervious Hyd. No. 17 Hydrograph Type = NRCS Runoff Peak Flow = 12.13 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 47,437 cuft Drainage Area = 1.18 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 7.0 min Total Rainfall = 11.60 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 12.13 cfs 13 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 Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B-U Hyd. No. 18 Hydrograph Type = Junction Peak Flow = 18.24 cfs Storm Frequency = 100-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 72,989 cuft Inflow Hydrographs = 15, 16, 17 Total Contrib. Area = 2.09 ac Qp = 18.24 cfs 20 19 18 17 16 15 14 13 12 11 Q (cfs) 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) PR-1B-U Open Space C PR-1B-U Woods C PR-1B-U Impervious PR-1B-U

= = PR-1B WATERSHED (COMBINED PROPOSED FLOW TO SWALE 1)

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B (Swale) Hyd. No. 21 Hydrograph Type = Junction Peak Flow = 6.200 cfs Storm Frequency = 2-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 23,599 cuft Inflow Hydrographs = 13 Total Contrib. Area = 0.35 ac Qp = 6.200 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-1B-D PR-1B-U PR-1B (Swale)

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1B (Swale) Hyd. No. 21 Hydrograph Type = Junction Peak Flow = 10.83 cfs Storm Frequency = 10-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 41,497 cuft Inflow Hydrographs = 13 Total Contrib. Area = 0.35 ac Qp = 10.83 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-1B-D PR-1B-U PR-1B (Swale)