Application of the Analytical Hierarchical Process for Improved Selection of Storm-Water BMPs

Engineers and planners responsible for the selection and design of storm-water best management practices (BMPs) face a formidable array of practices and techniques for managing the quality of urban runoff. Primary factors affecting the choice of BMP invariably include the performance capability of a given class of BMPs and the new impervious cover fraction arising from development projects. We introduce the analytical hierarchal process (AHP) as an analytical framework for BMP selection, through priority ranking of storm water control objectives and BMP performance metrics. Using the AHP, a BMP priority ranking is accomplished through the construction of pairwise relative rankings of the selection criteria and then of the BMPs themselves against the respective selection criteria. The use of normalized ranking vectors, obtained through eigenvector approximation, is employed to provide a final ranking of BMP choices that then can be carefully reviewed by the design engineer. Two BMP selection applications are included in the context of a residential/commercial development and a linear highway project.