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National Stormwater Management Calculator

Center for Neighborhood Technology

This online tool compares predevelopment, conventional development, and development with Green Stormwater BMPs for a single site. Results include changes in total runoff volume, pervious area, and life cycle costs. Inputs include: site size, predevelopment land cover, post development land cover, and parameters for Green Stormwater BMPs. Default values can be used where information is not available. The calculator uses zipcode to determine average annual rainfall. This tool can also be used to find a combination of BMPs that will meet a particular runoff reduction goal.


Stormwater management, Operations & maintenance savings, Bioretention, Green roof, Native Plants, Permeable paving, Rainwater harvesting, Trees

The LPS Benefits Toolkit is a compilation of online calculators and tools that can be used to estimate landscape performance. The Landscape Architecture Foundation (LAF) compiles and writes descriptions of the tools in the Benefits Toolkit. LAF has no involvement in the development, review, or maintenance of the tools. If you have questions or comments on the Toolkit itself, contact us at (email hidden; JavaScript is required).

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