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National Stormwater Calculator - Version 1.1 (Model)
Citation:
Rossman, L. National Stormwater Calculator - Version 1.1 (Model). U.S. Environmental Protection Agency, Washington, DC, EPA/600/C-13/106b, 2014.
Impact/Purpose:
Stormwater discharges continue to cause impairment of our Nation’s waterbodies. Regulations that require the retention and/or treatment of the frequent,small storms that dominate runoff volumes and pollutant loads are becoming more common. EPA has developed a desktop application, the National Stormwater Calculator, to help support local, state, and national stormwater management objectives in this regard.
Description:
EPA’s National Stormwater Calculator (SWC) is a desktop application that estimates the annual amount of rainwater and frequency of runoff from a specific site anywhere in the United States (including Puerto Rico). The SWC estimates runoff at a site based on available information such as soil type, landscape and land-use information, and weather. This update to SWC will allow users to consider how runoff may vary based both on historical weather and potential future climate. To better inform decisions, it is recommended that the user develop a range of SWC results with various assumptions about model inputs such as percent of impervious surface, soil type, sizing of green infrastructure, as well as historical weather and future climate scenarios. Please check with local authorities about whether and how use of these tools may support local stormwater management goals.