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

PAPS-1

Hydrograph Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-22-2025 PR-2B Routing Hyd. No. 57 Hydrograph Type = Pond Route Peak Flow = 0.124 cfs Storm Frequency = 2-yr Time to Peak = 93 min Time Interval = 1 min Hydrograph Volume = 1,416 cuft Inflow Hydrograph = 56 - PR-2B Max. Elevation = 553.40 ft Pond Name = PAPS-1 Max. Storage = 1,059 cuft Pond Routing by Storage Indication Method Center of mass detention time = 2.47 hrs Qp = 0.124 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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Time (hrs) PR-2B PR-2B Routing

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-22-2025 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 3000 4000 5000 6000

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

Pond Report File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-22-2025 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

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 Pond Outflow

SUMMARY

Hydrograph 2-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-22-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (min) (cuft) (ft) (cuft) 1 NRCS Runoff PR-1A-D Grass D 0.150 69 202 ---- 2 NRCS Runoff PR-1A-D Imp 0.924 65 1,127 ---- 3 Junction PR-1A-D 1.013 65 1,329 1, 2 5 NRCS Runoff PR-1A-U Open Space C 0.044 76 89.7 ---- 6 NRCS Runoff PR-1A-U Woods C 0.004 81 9.73 ---- 7 NRCS Runoff PR-1A-U Imp 1.444 65 1,760 ---- 8 Junction PR-1A-U 1.449 65 1,860 5, 6, 7 10 Junction PR-1A Total 2.461 65 3,188 3, 8 11 Pond Route PR-1A Routing 0.000 61 0.001 10 534.52 2,487 13 NRCS Runoff PR-1B-D 0.180 68 227 ---- 15 NRCS Runoff PR-1B-U Open Space C 0.036 77 76.3 ---- 16 NRCS Runoff PR-1B-U Woods C 0.027 83 72.9 ---- 17 NRCS Runoff PR-1B-U Impervious 3.349 66 4,321 ---- 18 Junction PR-1B-U 3.355 66 4,470 15, 16, 17 21 Junction PR-1B (Swale) 3.512 66 4,696 13, 18 24 NRCS Runoff PR-1C-D Open Space D 0.192 65 188 ---- 25 NRCS Runoff PR-1C-D Impervious 0.318 65 387 ---- 26 Junction PR-1C-D

D Open Space D 0.192 65 188 ---- 25 NRCS Runoff PR-1C-D Impervious 0.318 65 387 ---- 26 Junction PR-1C-D 0.510 65 576 24, 25 28 NRCS Runoff PR-1C-U Open Space C 0.103 75 195 ---- 29 NRCS Runoff PR-1C-U Impervious 3.417 65 4,206 ---- 30 Junction PR-1C-U 3.432 65 4,401 28, 29 32 Junction POA-1 7.380 65 9,673 11, 21, 26, 30 35 NRCS Runoff PR-2A-D Open Space D 0.412 68 518 ---- 36 NRCS Runoff PR-2A-D Impervious 1.213 65 1,479 ----

Hydrograph 2-yr Summary File: Eagle Rock Proposed (Future).hys Hydrology Studio v 3.0.0.39 10-22-2025 Hyd. Hydrograph Hydrograph Peak Time to Hydrograph Inflow Maximum Maximum Flow Peak Volume Hyd(s) Elevation Storage No. Type Name (cfs) (min) (cuft) (ft) (cuft) 37 Junction PR-2A-D 1.509 65 1,997 35, 36 39 NRCS Runoff PR-2A-U Open Space C 0.022 79 48.1 ---- 40 NRCS Runoff PR-2A-U Woods C 0.008 87 21.5 ---- 41 NRCS Runoff PR-2A-U Impervious 1.963 65 2,394 ---- 42 Junction PR-2A-U 1.965 65 2,464 39, 40, 41 45 Junction PR-2A 3.474 65 4,460 37, 42 46 Pond Route PR-2A Routing 0.000 58 0.000 45 537.39 3,332 48 NRCS Runoff PR-2B-D Open Space D 0.017 67 18.8 ---- 49 NRCS Runoff PR-2B-D Impervious 1.068 65 1,303 ---- 50 Junction PR-2B-D 1.083 65 1,322 48, 49 52 NRCS Runoff PR-2B-U Open Space C 0.002 66 2.50 ---- 53 NRCS Runoff PR-2B-U Impervious 0.087 65 106 ---- 54 Junction PR-2B-U 0.088 65 108 52, 53 56 Junction PR-2B 1.171 65 1,430 50, 54 57 Pond Route PR-2B Routing 0.124 93 1,416 56 553.40 1,059 59 NRCS Runoff PR-2C-D Open Space D 0.348 65 341 ---- 60 NRCS Runoff PR-2C-D Impervious 0.837 65 1,021 ---- 61