text: Two early examples of scientifically designed bioswales for large scale applications are found in the western US.  In 1996, for Willamette River Park in Portland, Oregon, a total of 2330 lineal feet of bioswale was designed and installed to capture and prevent pollutant runoff from entering the Willamette River. Intermittent check dams were installed to further abet silt capture, which reduced by 50% suspended solids entering the river system.
  A second example of a large scale designed bioswale is at the Carneros Business Park, Sonoma County, California. Starting in 1997 the project design team worked with the California Department of Fish and Game and County of Sonoma to produce a detailed design to channel surface runoff at the perimeter of a large parking area. Surface runoff consists of building roof runoff, parking lot runoff and overland flow from properties to the north of the project site.  A total of two lineal miles of bioswale was designed into the project.  The purpose of the bioswale was to minimize runoff contaminants from entering Sonoma Creek. The bioswale channel is grass-lined and nearly linear in form. Downslope gradient is approximately 4% and cross-slope gradient is approximately 6%.
  A relatively recent project established was the "Street Edge Alternatives" (SEA) project in Seattle, Washington, completed in 2001. Rather than using traditional piping, SEAs goal was to create a natural landscape that represented what the area was like before development. The street was 11% more pervious than a standard street and was characterized with evergreen trees and bioswales. The bioswales were planted on graded slopes with wetland and upland plants. Other landscaping also focused on native and salmon-friendly plants. SEA provided a strong benefit for stormwater runoff mitigation that helped continue to protect Seattles creek ecology. The project street also created a more inviting and aesthetically pleasing site as opposed to hard landscaping.
  The New York City Department of Environmental Protection (NYC DEP) has built more than 11,000 curbside bioswales, which are referred to as rain gardens. Rain gardens are constructed throughout the city to manage storm water and to improve the water quality of city waterways. The care and tending of rain gardens is a partnership between the NYC DEP and a group of citizen volunteers called "harbor protectors". Rain gardens are inspected and cleaned at least once a week.