Optimizing Retention Basin Networks

Retention basins are an effective and common means of flood control. Differing from detention, retention fully contains a particular storm event, using infiltration as the primary means of disposal. For a complex watershed with multiple subwatersheds; however, requiring basins to retain only flow from their contributing subwatershed may result in a suboptimal solution both in terms of cost and overall flood control. This paper introduces a design procedure for considering location and sizing of a network of retention basins within a watershed. It utilizes the discrete dynamic programming technique to determine the ideal locations and geometry for each basin. A design example demonstrates that this method may allow significant cost savings over traditional methods.