V3 RESUBMISSION Stormwater Management Report Rev 2 Dated November 3 2022

METHODOLOGY The USDA Natural Resources Conservation Service (NRCS) methodology described in the Technical Release 55 — Urban Hydrology for Small Water Sheds (TR-55) is used for computing stormwater runoff rates, volumes, and hydrographs for both existing and proposed conditions. In computing stormwater runoff from all design storms, the relative stormwater runoff rates and volumes of pervious and impervious surfaces are analyzed separately. The rainfall-duration- frequency data was taken from the NOAA National Weather Service (See attached). The NRCS Type D Design Storm Rainfall Distribution was used to analyze both pre-and post-conditions. Hydraflow Hydrographs Extension 2021 Modeling Software was used to compute the site's pre and post-development runoff. EXISTING CONDITIONS The existing conditions was analyzed to include the entire property and any offsite areas that currently drain onto the property. The existing drainage area was broken into 7 drainage areas totaling 20.16 acres. It should be noted that all open space within the existing Limit of Disturbance was modeled as Open Space — D, since it was already previously disturbed. Each of these drainage areas is explained in further detail below. DRAINAGE AREA 1A (DA-1A) Drainage Area 1A consists of 6.97 acres of both pervious and impervious surfaces that drain via storm sewers to the existing detention basin onsite. See below for a more detailed analysis of the existing detention basin. The pervious surface, 6.09 acres, consists of wooded and landscaped areas. The impervious surface, 0.88 was calculated for this drainage area. A time of concentration of 14.25 minutes was calculated for this drainage area, DRAINAGE AREA 1B (DA-1B) Drainage Area 1B consists of 0.24 acres of pervious surface that drains directly into the existing surface basin. These pervious areas are comprised primarily of existing wooded areas. A time of concentration of 9.78 minutes was calculated for this drainage area. DRAINAGE AREA 2 (DA-2) Drainage Area 2 consists of 0.60 acres of pervious area, which currently flows from the subject property and onto Kessler's driveway before making its way into the storm sewer system on Pleasant Valley Way. This drainage area includes both wooded areas along with some landscaped and lawn areas. A time of concentration of 10.14 minutes was calculated for this drainage area. DRAINAGE

Pleasant Valley Way. This drainage area includes both wooded areas along with some landscaped and lawn areas. A time of concentration of 10.14 minutes was calculated for this drainage area. DRAINAGE AREA 3 (DA-3) Drainage Area 3 consists of 4.54 acres of both pervious and impervious surfaces that drain to via onsite storm sewers directly into the storm sewer located in Pleasant Valley ° 2