2025 12 19 Stormwater Report Rev 1

storm event. (See attached Hydraflow Output for Existing Conditions Hydrographs, CN Values, and Time of Concentration Calculations.) Table 3 – Existing Peak Runoff Rates DA-1 Current Adjusted Rainfall Future Projected Rainfall Existing Site Existing Site Existing Site Existing Site Storm Event Peak Runoff Runoff Volume Peak Runoff Runoff Volume 2 Year 9.339 cfs 44,031 cf 11.28 cfs 53,349 cf 10 Year 15.35 cfs 73,038 cf 18.49 cfs 88,329 cf 100 Year 27.41 cfs 132,192 cf 34.83 cfs 169,002 cf DA-2 Current Adjusted Rainfall Future Projected Rainfall Existing Site Existing Site Existing Site Existing Site Storm Event Peak Runoff Runoff Volume Peak Runoff Runoff Volume 2 Year 0.271 cfs 1,209 cf 0.345 cfs 1,533 cf 10 Year 0.503 cfs 2,237 cf 0.627 cfs 2,796 cf 100 Year 0.978 cfs 4,428 cf 1.271 cfs 5,815 cf PROPOSED 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 and proposed 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 12.6 and 11.7 minutes, respectively. DRAINAGE

ea, one based on the current adjusted rainfall total and one for the future projected rainfall total. The times of concentration are 12.6 and 11.7 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 6