Harvesting the Rain: Decentralized Stormwater Management

Last Wednesday, the Los Angeles and San Gabriel Rivers Watershed Council (LASGRWC) held a symposium on harvesting rain as a means to manage stormwater in the LA area.  The symposium included a field trip to Elmer Avenue in Sun Valley, a pilot site for a green streets project.

The Watershed Council hosts quarterly symposia to provide a forum to discuss the issues related to watershed management and land use planning.  Diverse panelists offer various perspectives on relevant topics to engage and stakeholders and educate the public on pertinent watershed issues.  This particular symposium was focused on stormwater augmentation, and took a closer look at the significance of the Elmer Avenue Neighborhood Retrofit Project.

Presenter Nancy L.C. Steele (executive director of LASGRWC) presented a brief history of the water augmentation study, describing Southern California’s drought problem, and the importance of weaning ourselves off of imported water.  She presented an interesting and convincing case for capturing stormwater as a means of acquiring regional water independence for years to come.

According to Steele, Elmer Avenue was chosen on the basis of three criteria:  it had poor street conditions; good soil as to keep pollutants from entering the groundwater; and resident support and participation.  Completed in May 2010, the retrofit project includes the use of bio-swales and an infiltration gallery under the street.  The project is designed to reduce flooding, improve water quality, and to recharge local groundwater supplies (40% of California’s water is from groundwater).  The one-block section of Elmer Avenue was retrofitted to capture runoff, improve water conservation, reduce river pollution, restore natural habitats and green space, and to beautify the community.

The pilot site is monitored on a regular basis to measure groundwater recharge, landscape water conservation, and changes in property values.  Furthermore, homeowners receive training on how to maintain the new streets.  Many of the retrofits included implementing stormwater best management practices (BMPs) on private and public property.  The retrofits include installing permeable surfaces, planting drought-resistant native plants on lawns and sidewalks, building bio-swales along the streets, installing smart-irrigation controllers, and solar streetlights.  The neighborhood project is a test site that serves as a natural laboratory and model for sustainable private and public space design.  It also is an example of how many technologies and efforts can be integrated to address environmental restoration, water regeneration, and flood management.

Sidewalk Bio-Swale

Solar-Powered Streetlight

Permeable Driveway

Native vegetation on private lawn

Popularity: 43% [?]