12 2026 02 12 Crestmont CC Stormwater Management Report

steps) Total Tc (minutes) = 14 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Future Existing TC EX-2-D Pervious v1.2

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 = 0.774 cfs Storm Frequency = 2-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 3,137 cuft Drainage Area = 0.41 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.774 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 Woods D Hyd. No. 26 Hydrograph Type = NRCS Runoff Peak Flow = 1.707 cfs Storm Frequency = 2-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 6,941 cuft Drainage Area = 1.02 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.707 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 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 = 0.261 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 786 cuft Drainage Area = 0.07 ac Curve Number = 91.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.261 cfs 0.26 0.24 0.22 0.2 0.18 0.16 0.14 Q (cfs) 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 (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 = 3.799 cfs Storm Frequency = 2-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 12,701 cuft Drainage Area = 0.91 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.799 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 Hyd. No. 30 Hydrograph Type = Junction Peak Flow = 5.948 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 23,566 cuft Inflow Hydrographs = 25, 26, 27, 28 Total Contrib. Area = 2.41 ac Qp = 5.948 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 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 = 1.496 cfs Storm Frequency = 10-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 6,127 cuft Drainage Area = 0.41 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.496 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 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 = 3.463 cfs Storm Frequency = 10-yr Time to Peak = 12.20 hrs Time Interval = 1 min Runoff Volume = 14,085 cuft Drainage Area = 1.02 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 14.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 3.463 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 Gravel D Hyd. No. 27 Hydrograph Type = NRCS Runoff Peak Flow = 0.434 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 1,352 cuft Drainage Area = 0.07 ac Curve Number = 91.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.434 cfs 0.44 0.42 0.4 0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 Q (cfs) 0.22 0.2 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 (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 = 5.958 cfs Storm Frequency = 10-yr Time to Peak = 12.10 hrs Time Interval = 1 min Runoff Volume = 20,254 cuft Drainage Area = 0.91 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 4.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 5.958 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)