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

Channel Flow Sub-Total 0.002 hours Watershed or subarea Tc or Tt Total Tc (hours) = 0.214 hours (Add Sub-Total Tt from prior steps) Total Tc (minutes) = 13 minutes \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Time of Concentration Calcs\Future Existing TC EX-1-D Pervious v1.2

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 1.274 cfs Storm Frequency = 2-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 4,896 cuft Drainage Area = 0.65 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.274 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-1-D Woods D Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 1.356 cfs Storm Frequency = 2-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 5,225 cuft Drainage Area = 0.78 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 1.356 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-1-D Impervious Hyd. No. 3 Hydrograph Type = NRCS Runoff Peak Flow = 0.359 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 1,295 cuft Drainage Area = 0.09 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 4.08 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.359 cfs 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 Q (cfs) 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-1-D Hyd. No. 4 Hydrograph Type = Junction Peak Flow = 2.885 cfs Storm Frequency = 2-yr Time to Peak = 12.17 hrs Time Interval = 1 min Hydrograph Volume = 11,416 cuft Inflow Hydrographs = 1, 2, 3 Total Contrib. Area = 1.52 ac Qp = 2.885 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) EX-1-D Open Space D EX-1-D Woods D EX-1-D Impervious EX-1-D

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 2.457 cfs Storm Frequency = 10-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 9,562 cuft Drainage Area = 0.65 ac Curve Number = 80.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.457 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 Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Woods D Hyd. No. 2 Hydrograph Type = NRCS Runoff Peak Flow = 2.745 cfs Storm Frequency = 10-yr Time to Peak = 12.18 hrs Time Interval = 1 min Runoff Volume = 10,603 cuft Drainage Area = 0.78 ac Curve Number = 77.00 Tc Method = User Time of Conc. (Tc) = 13.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 2.745 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 Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Impervious Hyd. No. 3 Hydrograph Type = NRCS Runoff Peak Flow = 0.563 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 2,066 cuft Drainage Area = 0.09 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 6.37 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.563 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-1-D Hyd. No. 4 Hydrograph Type = Junction Peak Flow = 5.617 cfs Storm Frequency = 10-yr Time to Peak = 12.17 hrs Time Interval = 1 min Hydrograph Volume = 22,230 cuft Inflow Hydrographs = 1, 2, 3 Total Contrib. Area = 1.52 ac Qp = 5.617 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-1-D Open Space D EX-1-D Woods D EX-1-D Impervious EX-1-D

Hydrograph Report File: Eagle Rock Existing (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-1-D Open Space D Hyd. No. 1 Hydrograph Type = NRCS Runoff Peak Flow = 5.206 cfs Storm Frequency = 100-yr Time to Peak = 12.17 hrs Time Interval = 1 min Runoff Volume = 21,042 cuft Drainage Area = 0.65 ac Curve Number = 80.00 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 = 5.206 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)