NATIONAL STORMWATER CALCULATOR USER’S GUIDE – VERSION 1.1
Rossman, L. NATIONAL STORMWATER CALCULATOR USER’S GUIDE – VERSION 1.1. U.S. EPA Office of Research and Development, Washington, DC, EPA/600/R-13/085c, 2015.
The calculator is most appropriate for performing screening level rainfall runoff analysis for small footprint sites up to several dozen acres in size with uniform soil conditions.
The National Stormwater Calculator is a simple to use tool for computing small site hydrology for any location within the US. It estimates the amount of stormwater runoff generated from a site under different development and control scenarios over a long term period of historical rainfall. The analysis takes into account local soil conditions, slope, land cover and meteorology. Different types of low impact development (LID) practices (also known as green infrastructure) can be employed to help capture and retain rainfall on-site. Future climate change scenarios taken from internationally recognized climate change projections can also be considered.