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

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Open Space C Hyd. No. 38 Hydrograph Type = NRCS Runoff Peak Flow = 4.208 cfs Storm Frequency = 100-yr Time to Peak = 12.23 hrs Time Interval = 1 min Runoff Volume = 18,667 cuft Drainage Area = 0.86 ac Curve Number = 74.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 4.208 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Woods C Hyd. No. 39 Hydrograph Type = NRCS Runoff Peak Flow = 4.295 cfs Storm Frequency = 100-yr Time to Peak = 12.23 hrs Time Interval = 1 min Runoff Volume = 18,911 cuft Drainage Area = 0.95 ac Curve Number = 70.00 Tc Method = User Time of Conc. (Tc) = 18.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 4.295 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 Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Gravel C Hyd. No. 40 Hydrograph Type = NRCS Runoff Peak Flow = 0.695 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 2,368 cuft Drainage Area = 0.08 ac Curve Number = 89.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 0.695 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 (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Impervious Hyd. No. 41 Hydrograph Type = NRCS Runoff Peak Flow = 9.544 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Runoff Volume = 35,374 cuft Drainage Area = 1.05 ac Curve Number = 98.00 Tc Method = User Time of Conc. (Tc) = 5.0 min Total Rainfall = 9.24 in Design Storm = NOAA-D Storm Duration = 24 hrs Shape Factor = 484 Qp = 9.544 cfs 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 Time (hrs)

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 EX-2-U Hyd. No. 42 Hydrograph Type = Junction Peak Flow = 16.94 cfs Storm Frequency = 100-yr Time to Peak = 12.13 hrs Time Interval = 1 min Hydrograph Volume = 75,319 cuft Inflow Hydrographs = 38, 39, 40, 41 Total Contrib. Area = 2.94 ac Qp = 16.94 cfs 19 18 17 16 15 14 13 12 11 10 Q (cfs) 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) EX-2-U Open Space C EX-2-U Woods C EX-2-U Gravel C EX-2-U Impervious EX-2-U

TOTAL EXISTING FLOW TO POA-2

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 TOTAL POA-2 Hyd. No. 44 Hydrograph Type = Junction Peak Flow = 9.625 cfs Storm Frequency = 2-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 39,342 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 9.625 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 Time (hrs) EX-2-D EX-2-U TOTAL POA-2

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 TOTAL POA-2 Hyd. No. 44 Hydrograph Type = Junction Peak Flow = 17.05 cfs Storm Frequency = 10-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 71,409 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 17.05 cfs 19 18 17 16 15 14 13 12 11 10 Q (cfs) 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) EX-2-D EX-2-U TOTAL POA-2

Hydrograph Report File: Eagle Rock Existing (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 TOTAL POA-2 Hyd. No. 44 Hydrograph Type = Junction Peak Flow = 32.74 cfs Storm Frequency = 100-yr Time to Peak = 12.12 hrs Time Interval = 1 min Hydrograph Volume = 141,014 cuft Inflow Hydrographs Total Contrib. Area = 0.0 ac Qp = 32.74 cfs 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 Q (cfs) 19 18 17 16 15 14 13 12 11 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) EX-2-D EX-2-U TOTAL POA-2

TOTAL ALLOWABLE FLOW TO POA-2