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

PR-2B WATERSHED POND ROUTING

Pond Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PAPS-1 Stage-Storage User Defined Contours Stage / Storage Table Description Input Stage Elevation Contour Area Incr. Storage Total Storage (ft) (ft) (sqft) (cuft) (cuft) Bottom Elevation, ft 553.00 0.00 553.00 6,586 0.000 0.000 Voids (%) 40.00 1.00 554.00 6,586 2,634 2,634 Volume Calc Ave End Area 2.00 555.00 6,586 2,634 5,269 3.00 556.00 6,586 2,634 7,903 Stage-Storage 556 3 555 2 554 1 553 0 0 1000 2000

0 0 1000 2000 3000 4000 5000 6000 7000 Total Storage (cuft) 2-yr 10-yr 25-yr 100-yr Contours

Pond Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PAPS-1 Stage-Discharge Orifice Culvert / Orifices Cir Culvert Perforated Riser 1 (i) 2 (i) 3 Rise, in 3 3 Hole Diameter, in Span, in 3 3 No. holes No. Barrels 1 1 Invert Elevation, ft Invert Elevation, ft 553.00 554.80 Height, ft Orifice Coefficient, Co 0.60 0.60 Orifice Coefficient, Co Length, ft Barrel Slope, % N-Value, n Weir Weirs Riser Ancillary 1 2 3 Shape / Type Exfiltration, in/hr Crest Elevation, ft Crest Length, ft Angle, deg

Exfiltration, in/hr Crest Elevation, ft Crest Length, ft Angle, deg Weir Coefficient, Cw m = Flows through Culvert, i = Independent Stage-Discharge 556 3 555 2 554 1 553 0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 Discharge (cfs) Top of Pond 2-yr 10-yr 25-yr 100-yr Pond Outflow

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B Routing Hyd. No. 57 Hydrograph Type = Pond Route Peak Flow = 0.184 cfs Storm Frequency = 2-yr Time to Peak = 12.62 hrs Time Interval = 1 min Hydrograph Volume = 4,595 cuft Inflow Hydrograph = 56 - PR-2B Max. Elevation = 553.73 ft Pond Name = PAPS-1 Max. Storage = 1,923 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.64 hrs Qp = 0.184 cfs 2 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (hrs) PR-2B PR-2B Routing

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B Routing Hyd. No. 57 Hydrograph Type = Pond Route Peak Flow = 0.246 cfs Storm Frequency = 10-yr Time to Peak = 12.82 hrs Time Interval = 1 min Hydrograph Volume = 7,429 cuft Inflow Hydrograph = 56 - PR-2B Max. Elevation = 554.20 ft Pond Name = PAPS-1 Max. Storage = 3,173 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.85 hrs Qp = 0.246 cfs 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (hrs) PR-2B PR-2B Routing

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B Routing Hyd. No. 57 Hydrograph Type = Pond Route Peak Flow = 0.283 cfs Storm Frequency = 25-yr Time to Peak = 12.92 hrs Time Interval = 1 min Hydrograph Volume = 9,422 cuft Inflow Hydrograph = 56 - PR-2B Max. Elevation = 554.56 ft Pond Name = PAPS-1 Max. Storage = 4,100 cuft Pond Routing by Storage Indication Method Center of mass detention time = 3.05 hrs Qp = 0.283 cfs 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (hrs) PR-2B PR-2B Routing

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2B Routing Hyd. No. 57 Hydrograph Type = Pond Route Peak Flow = 0.476 cfs Storm Frequency = 100-yr Time to Peak = 12.67 hrs Time Interval = 1 min Hydrograph Volume = 13,183 cuft Inflow Hydrograph = 56 - PR-2B Max. Elevation = 555.14 ft Pond Name = PAPS-1 Max. Storage = 5,649 cuft Pond Routing by Storage Indication Method Center of mass detention time = 3.15 hrs Qp = 0.476 cfs 4 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (hrs) PR-2B PR-2B Routing

FUTURE POND ROUTING CALCULATIONS