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CENTER STREET AREA FRAMEWORK + POLICY PLAN <br />Stormwater Management System Project I cements <br />Rainfall Event <br />V Event <br />Rainfall Depth <br />(IN) <br />1.00 <br />Runoff <br />Volume (CF) <br />5500 <br />Runoff <br />Vol u me (GA) <br />41,140 <br />1-Year <br />2,46 <br />14,700 <br />109JP956 <br />2-Year <br />7.86 <br />17.1600 <br />1311648 <br />5-Year <br />3.58 <br />221700 <br />1691796 <br />10-Year <br />4426 <br />27.1500 <br />2051700 <br />Table 1: Summary of expected runoff volumes. <br />Additional Considerations <br />A simplified estimate of stormwater runoff expected <br />from the street section was assembled to ensure the <br />watershed can produce enough runoff to adequately <br />fill the tanks. Table 1 is a summary of expected runoff <br />volumes for a variety of events. A rainfall event producing <br />between 3.6 and 4.3 inches in 24 hours (5-year to <br />10-year return interval) can completely fill the tank. <br />During final design, additional hydraulic information will <br />be provided to provide an effective high flow bypass <br />system. In other words, if the tank is full and the City <br />experiences a 100-year rainfall event, there will be <br />adequate bypass capacity to reduce local flooding and <br />protect the tank(s). Also, since the COR trunk storm <br />sewer system is already designed to accommodate a <br />100-year rainfall event with discharge to regional flood <br />storage areas, the bypass system will effectively mimic <br />the originally designed scenario. In between events <br />when irrigation is occurring, or the tanks is being filled, <br />there will be hydraulic relief on the trunk system and <br />volume control provided. <br />Since the reuse water will pass through a filter and <br />potentially other treatment methods, the impact <br />to groundwater resources through the infiltration <br />of irrigation water is expected to be very minimal. <br />Impacts to groundwater resources in the ERA are <br />29 <br />