Return to Benefits Toolkit

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, Trees, Rainwater harvesting, Permeable paving, Bioretention, Native plants, Green roof

The LPS Fast Fact Library is a collection of short summaries of landscape benefits derived from published research. The Landscape Architecture Foundation (LAF) compiles and writes the Fast Facts. LAF has no involvement in the data collection, analysis, review, publication, or funding of the research. If you have questions or comments on the Fast Fact Library itself, contact us at email hidden; JavaScript is required.

Help build the LPS: Find out how to submit a case study and other ways to contribute.