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This fact sheet is one of a 15-part series on urban stormwater management practices.
Please refer to definitions in the glossary at the end of this fact sheet. Glossary terms are italicized on first mention in the text. For a comprehensive list, see Virginia Cooperative Extension (VCE) publication 426-119, “Urban Stormwater: Terms and Definitions.”
Grass channels (GCs) are wide, gently sloping, open channels with grass sides used as a stormwater conveyance system (see figure 1). Grass channels are similar to ditches; however, their side slopes are much more gradual. GCs provide treatment via filtering through vegetation. When compared with traditional curb and gutter, or inlets and pipes, which remove no pollutants, GCs may provide a modest amount of runoff reduction and pollutant removal. The extent of this reduction depends on the underlying soil characteristics, slope, and flow velocity. At higher velocities, stormwater is only conveyed and is not treated. Unlike dry swales, (VCE publication 426-129), GCs do not include a soil media and/or specific storage volume.
Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.
Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.
December 11, 2019