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

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 SSBB-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 534.00 0.00 534.00 4,713 0.000 0.000 Voids (%) 100.00 1.00 535.00 4,938 4,825 4,825 Volume Calc Conic 2.00 536.00 5,145 5,041 9,865 3.00 537.00 5,354 5,249 15,114 4.00 538.00 5,649 5,500 20,614 5.00 539.00 6,413 6,026 26,641 Stage-Storage 539 5 538 4 537 3 536 2 535

2 535 1 534 0 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 24000 26000 Total Storage (cuft) 2-yr Contours

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 SSBB-1 Stage-Discharge Orifice Culvert / Orifices Cir Culvert Perforated Riser 1 (m) 2 (m) 3 Rise, in 18 4 4 Hole Diameter, in Span, in 18 12 14 No. holes No. Barrels 1 1 1 Invert Elevation, ft Invert Elevation, ft 530.25 534.60 535.40 Height, ft Orifice Coefficient, Co 0.60 0.60 0.60 Orifice Coefficient, Co Length, ft 47 Barrel Slope, % 7.34 N-Value, n 0.013 Weir Weirs Riser Ancillary

Riser Ancillary 1 (m) 2 3 Shape / Type Rectangular Exfiltration, in/hr 1.50** Crest Elevation, ft 536.1 Crest Length, ft 3.5 Angle, deg Weir Coefficient, Cw 3.3 m = Flows through Culvert, i = Independent **Exfiltration extracted from outflow hydrograph. Rate applied to contours. Stage-Discharge 539 5 538 4 537 3 536 2 535 1 534 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

8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Discharge (cfs) Top of Pond 2-yr Pond Outflow

SMALL-SCALE BIORETENTION BASIN 2

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2A Routing Hyd. No. 46 Hydrograph Type = Pond Route Peak Flow = 0.000 cfs Storm Frequency = 2-yr Time to Peak = 58 min Time Interval = 1 min Hydrograph Volume = 0.000 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 537.39 ft Pond Name = SSBB-2 Max. Storage = 3,332 cuft Pond Routing by Storage Indication Method Qp = 0.000 cfs 4 3 2 1 0 -1 0 10 20 30 40 50 60 70 Time (min) Req'd Stor PR-2A PR-2A Routing

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 SSBB-2 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 537.00 0.00 537.00 7,745 0.000 0.000 Voids (%) 100.00 1.00 538.00 9,163 8,443 8,443 Volume Calc Conic 2.00 539.00 10,607 9,875 18,318 3.00 540.00 12,084 11,337 29,655 4.00 541.00 13,601 12,834 42,489 5.00 542.00 15,155 14,369 56,858 Stage-Storage 542 5 541 4 540 3 539 2 538 1 537

1 537 0 0 10000 20000 30000 40000 50000 Total Storage (cuft) 2-yr Contours

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-21-2025 SSBB-2 Stage-Discharge Orifice Culvert / Orifices Cir Culvert Perforated Riser 1 (m) 2 (m) 3 Rise, in 18 4 6 Hole Diameter, in Span, in 18 9 16 No. holes No. Barrels 1 1 2 Invert Elevation, ft Invert Elevation, ft 533.50 537.40 538.30 Height, ft Orifice Coefficient, Co 0.60 0.60 0.60 Orifice Coefficient, Co Length, ft 36 Barrel Slope, % 1.5 N-Value, n 0.012 Weir Weirs Riser Ancillary 1 (m) 2 3 Shape