A runoff footprint is the total surface runoff that a site produces over the course of a year. According to the United States Environmental Protection Agency (EPA) stormwater is "rainwater and melted snow that runs off streets, lawns, and other sites". Urbanized areas with high concentrations of impervious surfaces like buildings, roads, and driveways produce large volumes of runoff which can lead to flooding, sewer overflows, and poor water quality. Since soil in urban areas can be compacted and have a low infiltration rate, the surface runoff estimated in a runoff footprint is not just from impervious surfaces, but also pervious areas including yards. The total runoff is a measure of the site’s contribution to stormwater issues in an area, especially in urban areas with sewer overflows. Completing a runoff footprint for a site allows a property owner to understand what areas on his or her site are producing the most runoff and what scenarios of stormwater green solutions like rain barrels and rain gardens are most effective in mitigating this runoff and its costs to the community.