12 2026 02 12 Crestmont CC Stormwater Management Report

runoff rates for the 2-, 10-, and 100-year design storm events are 50, 75, and 80%, respectively, of the pre-construction runoff rates for the portions of the site on which the proposed development is to be constructed and quantity control BMPs are required to be implemented. Watersheds noted as being “disturbed” in the watershed descriptions in Section 3.1.4 of this report represent the areas on the project site that are to be disturbed as part of the proposed redevelopment and are therefore subject to post-construction peak rate reductions if post- construction peak runoff rates exceed pre-construction peak runoff rates and quantity control BMP’s are required to be implemented. Watersheds noted as being “undisturbed” in the watershed descriptions in Section 3.1.4 of this report represent the areas on the project site that are to remain undisturbed as part of the proposed redevelopment and are therefore not subject to peak rate reductions. The following section summarizes the quantity control criteria being established for each point of analysis, which watersheds are subject to peak rate reductions, and the allowable peak discharges for each point of analysis. • Point of Analysis 1 (POA-1): The proposed development within this watershed results in peak runoff rates increasing in the proposed condition, and quantity control BMPs are required to be implemented. Therefore, it shall be demonstrated in accordance with N.J.A.C. 7:8-5.6.(b).3 that the post-construction peak runoff rates for both the current and future 2-, 10-, and 100-year design storm events are 50, 75, and 80%, respectively, of the pre-construction runoff rates for the disturbed portions of the overall watershed. Table 7 – POA-1 Allowable Peak Discharges (Current) Design Storm Existing Peak Allowable Peak Event Discharge (CFS) Discharge (CFS) 2-Year 13.48 12.57 10-Year 23.47 22.52 100-Year 44.56 42.92 Note: Total Allowable Peak Discharges are calculated by hydraulically adding runoff hydrographs and may not reflect the

100-Year 44.56 42.92 Note: Total Allowable Peak Discharges are calculated by hydraulically adding runoff hydrographs and may not reflect the direct addition of peak discharge rates. Refer to the hydrograph report calculations in Appendix A. 9