Municipalities tend to develop their stormwater management policy by examining those of their neighboring communities, chosen out of convenience and perception of similarity rather than a purposeful, directed search. Alternatively, having a policy that is backed by science creates regulations that policy makers can confidently support. To address this issue, the model used in this study incorporates local rainfall and development data to analyze stormwater runoff volumes for various storm events using one year of development data from Chattanooga, Tennessee. The runoff values are used to analyze several policy combinations based on simplified policies, model policies, and customizable policies. Outputs of the tool include project count, impervious area managed, runoff managed, and runoff cleaned. This study indicates that stormwater managers can use the outputs of this tool to choose the policy that best meets their city’s unique goals.