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-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

3 539 2 538 1 537 0 0 10000 20000 30000 40000 50000 Total Storage (cuft) 2-yr 10-yr 25-yr 100-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 / Type Rectangular Exfiltration, in/hr Crest Elevation, ft 539.4 Crest Length, ft

angular Exfiltration, in/hr Crest Elevation, ft 539.4 Crest Length, ft 2.5 Angle, deg Weir Coefficient, Cw 3.3 m = Flows through Culvert, i = Independent Stage-Discharge 542 5 541 4 540 3 539 2 538 1 537 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 Discharge (cfs) Top of Pond 2-yr 10-yr 25-yr 100-yr Pond Outflow

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 = 1.017 cfs Storm Frequency = 2-yr Time to Peak = 12.63 hrs Time Interval = 1 min Hydrograph Volume = 19,304 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 538.28 ft Pond Name = SSBB-2 Max. Storage = 11,216 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.78 hrs Qp = 1.017 cfs 7 6 5 4 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 Time (hrs) PR-2A PR-2A Routing

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 = 4.038 cfs Storm Frequency = 10-yr Time to Peak = 12.27 hrs Time Interval = 1 min Hydrograph Volume = 36,206 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 538.75 ft Pond Name = SSBB-2 Max. Storage = 15,826 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.11 hrs Qp = 4.038 cfs 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 26 27 28 29 30 Time (hrs) PR-2A PR-2A Routing

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 = 6.082 cfs Storm Frequency = 25-yr Time to Peak = 12.25 hrs Time Interval = 1 min Hydrograph Volume = 49,644 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 539.07 ft Pond Name = SSBB-2 Max. Storage = 19,070 cuft Pond Routing by Storage Indication Method Center of mass detention time = 1.82 hrs Qp = 6.082 cfs 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 26 27 28 29 Time (hrs) PR-2A PR-2A Routing

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 = 9.295 cfs Storm Frequency = 100-yr Time to Peak = 12.23 hrs Time Interval = 1 min Hydrograph Volume = 76,666 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 539.63 ft Pond Name = SSBB-2 Max. Storage = 25,429 cuft Pond Routing by Storage Indication Method Center of mass detention time = 1.54 hrs Qp = 9.295 cfs 26 25 24 23 22 21 20 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 26 27 28 Time (hrs) PR-2A PR-2A Routing

PR-2B WATERSHED POND ROUTING

Pond Report File: Eagle Rock Proposed (Future).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