With funding from the U.S. Environmental Protection Agency, the Agricultural Research Service is building a mock residential housing development on rolling farmland in Coshocton, Ohio, to find out what happens to streams and lakes as farmland is urbanized.
EPA plans to use the results of this first, fully controlled study of water runoff to create a national program to trade runoff credits, just as air pollution credits are now traded.
Each year, ARS hydraulic engineer James Bonta and colleagues at the agency's North Appalachian Experimental Watershed in Coshocton will increase "development" until it covers 40 percent of each of the four watersheds they are working on. The watersheds range in size from one to seven acres.
Annual runoff from these watersheds has been monitored for many years, as has land use. This will provide long-term background data for comparison as "urbanization" proceeds.
Development replaces soil and vegetation that once soaked up rainwater and snowmelt with the impervious surfaces of roofs and roads. These changes increase the volume and speed of water runoff, increasing the risk of flooding, soil erosion and the transport of chemicals into waterways.
The scientists will build 3-foot-high "houses" covered with plastic. They will plow soil to simulate construction work, and they will plant lawns and use pesticides and fertilizers just as homeowners do.
Then they will measure the rate of increase in volume and peak flow rate of runoff and the increase in amounts of fertilizers, sediment and perhaps pesticides that end up in streams and lakes.
The researchers will also evaluate ways to reduce the runoff, such as installing roof gardens to trap rainwater and intermixing natural areas with homes and paved areas, to give water a chance to soak in before reaching waterways.
The EPA's Sustainable Environments Branch in Cincinnati, Ohio, is conducting this research jointly with ARS as a pilot program to find the most cost-effective ways to improve water quality.
ARS is the U.S. Department of Agriculture's chief scientific research