2025 12 19 Stormwater Report Rev 1

EXISTING CONDITIONS The existing site has been modeled as two drainage areas totaling 4.86 acres. (See Fig.1 Existing Drainage Area Map.) The point of analysis for Drainage Area 1 is the Type Double “B” Inlet at the rear of the site, which connects to the municipal storm sewer system within Deerfield Drive. The point of analysis for Drainage Area 2 is the rear property line that bypasses. The drainage areas include all areas of disturbance, as well as any other areas that drain to the point of analyses. DRAINAGE AREA 1 (DA-1) Drainage Area 1 consists of 4.68 acres of both pervious and impervious surfaces. The impervious area, 3.32 acres, consists of the existing parking lot and associated improvements. The pervious area, 0.27 acres, is comprised of landscaped and lawn areas that are in good condition. Two times of concentration have been calculated for this drainage area, one based on the current adjusted rainfall total and one for the future projected rainfall total. The times of concentration are 13.6 and 12.7 minutes, respectively. DRAINAGE AREA 2 (DA-2) Drainage Area 2 consists of 0.18 acres of both pervious and impervious surfaces. The impervious area, 0.04 acres, consists of walkways. The pervious area, 0.14 acres, is comprised of landscaped and lawn areas that are in good condition. Two times of concentration have been calculated for this drainage area, one based on the current adjusted rainfall total and one for the future projected rainfall total. The times of concentration are 11.8 and 10.9 minutes, respectively. CURVE NUMBERS The CN values used have been taken from the TR-55 Manual “Urban Hydrology for Small Watersheds,” Table 2-2a and Table 2-2c, based on land cover and hydrologic soil groups. Table 2 – Curve Number (Existing Conditions) Description Hydrologic Group Curve Number Landscaped Islands D 80 (Open Space-Good Conditions) Impervious D 98 PEAK FLOWS Using the information described above, the peak flows during the 2-, 10-, and 100-year storm events where calculated. Table 2 below summarizes the peak flows during

98 PEAK FLOWS Using the information described above, the peak flows during the 2-, 10-, and 100-year storm events where calculated. Table 2 below summarizes the peak flows during each 5