Oregon: Portland (Glencoe Elementary School)

Green Infrastructure Type: Green Campuses

Types of Green Infrastructure Used:

Summary:

Rain Garden at Glencoe Elementary School

Description:
Between 2002 and 2003, the City of Portland funded retrofitting projects at the Glencoe Elementary School which included a rain garden and a vegetative infiltration swale with landscaping to redirect stormwater runoff at the school. These retrofits manage runoff from a 40,000 square foot catchment area. The swale and rain garden have assisted in eliminating the problem of basement flooding in neighborhood homes and helped to improve water quality.

The City of Portland and the Portland Parks and Recreation Bureau, in partnership with the Portland Public Schools, implemented a parking lot retrofit project to reduce the amount of impervious surface at Glencoe Elementary School. Through a grant from the Willamette Stormwater Control Program, the city redesigned the school's parking lot to include less parking spaces and a vegetative infiltration swale to manage stormwater from the site. The goal of the project was to maximize capacity to capture runoff from the area while still preserving parking spaces. The main components of the parking lot retrofit included a vegetative swale with check dams that runs along the length of the lot, landscaping, and speed bumps. The 150 foot by 6 foot swale was designed to capture the runoff from the parking lot and allow it to infiltrate through three large holding areas that are planted with native grasses and plants. Overflow from the swale is directed to the north end of the retrofit where it is redistributed to the Glencoe Rain Garden. The landscaped area of 4,600 square feet (including the stormwater swale) was planted with 24 trees-Red Maples, Dogwood, Vine Maples, and Douglas Firs-and an irrigation system for summertime watering. Two berms are used as speed bumps across the parking lot, rerouting runoff into the swale in different locations for even distribution. The success of the swale is a proven example of how to incorporate green infrastructure practices without eliminating the practical use of the area.

Also as a collaborative effort between the City of Portland, Portland Public Schools, and various contractors, the Glencoe Elementary Rain Garden project converted a previously large grassy area adjacent to the school into an innovative rain garden designed to collect runoff from adjacent streets, reduce stormwater in the sewer system, and help prevent local basement flooding and combined sewer overflows. The rain garden mimics natural hydrologic conditions of the site, which allows runoff to filter through vegetation and soil media, before soaking into the ground. The rain garden also adds aesthetic appeal to the campus and surrounding area and is used as an educational resource for students and the community.

The catchment area for the rain garden consists of a vegetative swale running along the school parking lot; the school entrance; and Morrison Street and SE 51st Avenue. The overall project goal was to reduce sewer overflows for residents on SE 52nd Avenue. Since its completion the rain garden has successfully captured 30-40% of the runoff from the catchment area and data also showed a retention rate of 95%. To date, the rain garden has not exceeded it holding capacity.

For more information, visit the Portland Bureau of Environmental Services Web site at http://www.portlandonline.com/Bes/index.cfm?a=78198&c=45388 and http://www.portlandonline.com/shared/cfm/image.cfm?id=147510 .

Office of Water | Office of Wastewater Management | Disclaimer | Search EPA

EPA Home | Privacy and Security Notice | Contact Us

Last updated on September 10, 2009 10:55 AM
URL:http://cfpub.epa.gov/npdes/greeninfrastructure/gicasestudies_specific.cfm