Design considerations for multiple detention systems

Design of a detention system is often subject to the constraints of upstream and downstream conditions. This study summarizes the design considerations of the Lower detention basin on the Western Tributary Wash in the North Las Vegas City. Storm centering tests were applied to the 103 square mile watershed area for determining the critical storm size and centering. The outfall channel in this case collects the release from the Lower detention basin, and then joins the Gowan outfall channel which carries a local flow from 11 square miles. Both assumptions of a single storm and dual storm events were examined in this study in order to identify the optimal combinations of basin release and storage volume subject to the critical flow capacity of the outfall channel at the confluence.