Optimization Tool


The Optimization Tool is intended to assist stormwater managers with selecting the best LID placement alternatives among the many options available that satisfy user-defined management targets. It uses an evolutionary optimization technique (Non-dominated Sorting Genetic Algorithm II) to evaluate the benefits (runoff and pollutant load reductions) and costs associated with various LID implementation scenarios (location, number, type, and size of LIDs) and identify the most cost-effective options for achieving desired flow mitigation and pollutant reduction at minimum cost.  The tool incorporates site information from the GIS Site Locator Tool and local cost information, and is interacted with the modeling tool during the search process in an iterative and evolutionary fashion to systematically generate viable LID scenarios and compare their performance.


The Optimization Tool provides critically needed support to stormwater managers at all levels for selection and placement of LID at strategic locations in urbanized watersheds for stormwater runoff or pollutant control.  The tool develops and evaluates alternative management scenarios and identifies the optimal combination of LID location, type, size to meet specific management goals on the basis of cost and effectiveness. The tool generates a cost- and pollutant-reduction effectiveness relationship that provides quantitative information on a range of optimal LID solutions for achieving various reduction goals at minimum costs to facilitate decision making.  The outputs of the tool can be overlaid with the LID opportunity maps produced by the Site Locator Tool to create a map /tabular output of suitable and most effective locations for LID implementation for achieving specific reduction objectives.  


The Optimization Tool is designed to help local watershed planning agencies to develop stormwater management plans and coordinate watershed-scale investments to meet their program needs. It is intended for knowledgeable users familiar with LIDs and the technical aspects of watershed modeling. The tool outputs, combined with other site specific information and management requirements, can be used to develop watershed-scale Green Infrastructure master plans.