Planning Detention Storage for Stormwater Management

Abstract

A method for estimating detention storage capacity in stormwater management is presented. A generalized storage‐overflow relationship is derived. This relationship defines real available storage (empty space in detention basin) on the positive range and overflow volumes on the negative range. By using exponential probability density functions for the independent hydrologic variables runoff volumes, runoff durations, and interevent times, and the generalized storage relationship, a new probability distribution is derived for the treatment plant overflow volumes. The new distribution provides an easy‐method for estimating the detention storage and treatment capacity for a design risk level. The methodology has the advantage that it provides easy to use preliminary planning information for stormwater management without the need for extensive simulation.