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West Seneca Sewer Report | Page 8 Table 5: Required RRv Total Minimum Soil Soil Soil Soil Increase in Weighted RRv Group A Group B Group C Group D Rv Impervious S Factor Required (%) (%) (%) (%) Area (Ac) (cf) 1.92 0 0 0 100 0.95 0.20 1,324 4.4 Provided WQv and RRv The following table summarizes both the water quality volume and reduced runoff volume provided by each practice: Stormwater Practice WQv Treated (cf) RRv Provided (cf) Bioretention (3 total areas) 3,338 1,337 Water Quality Unit 6,627 0 Total 9,965 1,337 Based on the above table, the WQv and RRv requirements are being met. 4.5 Discharge Rates A comparison of the pre- and post-development watershed conditions was performed for all Design Points and storm events evaluated. For all Design Points and design storms, this comparison demonstrates that the peak rate of runoff will not be increased. Therefore, the project will not have a significant adverse impact on the adjacent or downstream properties or receiving water courses. The results of the computer modeling used to analyze the pre- and post-development watersheds are presented in the following table below: Table 6: Summary of Pre-Development and Post-Development Peak Discharge Rates 10-year 24-hour storm event 100-year 24-hour storm event Analysis Point (AP) Pre Post Pre Post 1 16.3 13.9 36.8 31.7 Based on the table above, the proposed stormwater flows have been reduced for all storm events to below pre-development conditions. A full stormwater pollution prevention plan per NYS Stormwater Design Manual, NYSDEC SPDES General Permit for Stormwater Discharge from Construction Activity and NYSDEC Page 80 of 359