On Jan. 30, the U.S. Environmental Protection Agency (EPA) released an update to the National Stormwater Calculator, adding a climate assessment tool that allows the calculator to assess future climate vulnerability scenarios. The calculator now includes changes in seasonal precipitation levels, the effects of more frequent high-intensity storms, and changes in evaporation rates based on validated climate change scenarios by the Intergovernmental Panel on Climate Change.

The updated calculator includes climate models that can be incorporated into the calculation of stormwater runoff. This adds future climate scenarios to last year’s Phase 1 release, which estimates the annual amount of stormwater runoff from a specific location and takes into account local soil conditions, slope, land cover, and historical rainfall records.

Users can enter any U.S. location and select different scenarios to learn how specific green infrastructure changes, including inexpensive modifications such as rain barrels and rain gardens, can reduce stormwater runoff. This information shows users how adding green infrastructure can be one of the most cost-effective ways to reduce stormwater runoff.