
ARS Builds
Mock Village on Farmland To Measure Runoff Effects on Water QualityBy Don Comis June 30, 2003With 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 agency. U.S. Department of Agriculture |