The Environmental Protection Agency (EPA) recently updated its national stormwater calculator, which estimates the amount of rainwater and runoff from any site in the U.S., to reflect best estimates on future climate change. The EPA writes: “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 Intergovernmental Panel on Climate Change (IPCC) climate change scenarios.†The first iteration of the calculator just covered soils conditions, slope, land cover, and historical rainfall records.
The goal is help developers, planners, and landscape architects understand how to best adapt our water management systems for a changing future. The new EPA administrator, Gina McCarthy, said: “climate change threatens our health, our economy, and our environment. As part of the President’s Climate Action Plan, this tool will help us better prepare for climate impacts by helping build safer, sustainable, and more resilient water infrastructure.â€
The calculator software, which can be downloaded free, enables users to discover how green infrastructure can reduce stormwater runoff. According to the EPA, the calculator first accesses several databases that offer soil, topography, rainfall, and evaporation information for any given site. Users then plug in information about a site’s land cover and finally determine which types of green infrastructure they would like to use. Options include rain harvesting, rain gardens, green roofs, street planters, infiltration basins, or porous pavement.
The EPA says it’s best to develop a range of results using different assumptions about “percent of impervious surface, soil type, sizing of green infrastructure, as well as historical weather and future climate change scenarios†in order to comprehensive.
Download the new calculator from the following web page, which includes instructions for downloading: http://www.epa.gov/nrmrl/wswrd/wq/models/swc/.
