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

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-1A Routing Hyd. No. 11 Hydrograph Type = Pond Route Peak Flow = 6.121 cfs Storm Frequency = 100-yr Time to Peak = 12.22 hrs Time Interval = 1 min Hydrograph Volume = 39,166 cuft Inflow Hydrograph = 10 - PR-1A Total Max. Elevation = 536.47 ft Pond Name = SSBB-1 Max. Storage = 12,336 cuft Pond Routing by Storage Indication Method Center of mass detention time = 1.21 hrs Qp = 6.121 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 Time (hrs) PR-1A Total PR-1A Routing

PR-2A WATERSHED POND ROUTING

Pond Report File: Eagle Rock Proposed (Current).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 (Current).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 (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2A Routing Hyd. No. 46 Hydrograph Type = Pond Route Peak Flow = 0.856 cfs Storm Frequency = 2-yr Time to Peak = 12.62 hrs Time Interval = 1 min Hydrograph Volume = 14,915 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 538.07 ft Pond Name = SSBB-2 Max. Storage = 9,171 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.85 hrs Qp = 0.856 cfs 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 (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2A Routing Hyd. No. 46 Hydrograph Type = Pond Route Peak Flow = 2.457 cfs Storm Frequency = 10-yr Time to Peak = 12.37 hrs Time Interval = 1 min Hydrograph Volume = 28,753 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 538.57 ft Pond Name = SSBB-2 Max. Storage = 14,024 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.38 hrs Qp = 2.457 cfs 10 9 8 7 6 5 4 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (hrs) PR-2A PR-2A Routing

Hydrograph Report File: Eagle Rock Proposed (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2A Routing Hyd. No. 46 Hydrograph Type = Pond Route Peak Flow = 4.531 cfs Storm Frequency = 25-yr Time to Peak = 12.25 hrs Time Interval = 1 min Hydrograph Volume = 38,803 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 538.80 ft Pond Name = SSBB-2 Max. Storage = 16,329 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.04 hrs Qp = 4.531 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 (Current).hys Hydrology Studio v 3.0.0.39 10-21-2025 PR-2A Routing Hyd. No. 46 Hydrograph Type = Pond Route Peak Flow = 6.883 cfs Storm Frequency = 100-yr Time to Peak = 12.25 hrs Time Interval = 1 min Hydrograph Volume = 58,144 cuft Inflow Hydrograph = 45 - PR-2A Max. Elevation = 539.24 ft Pond Name = SSBB-2 Max. Storage = 21,029 cuft Pond Routing by Storage Indication Method Center of mass detention time = 1.71 hrs Qp = 6.883 cfs 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 29 Time (hrs) PR-2A PR-2A Routing