**This project was showcased as a "Bay Area Success Story" by the State Water Resources Control Board.
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With a lot of hard work, local support, and creative thinking, a small grassroots community group in Marin County, California, has completed a model stormwater capture project that protects coho salmon streams, reduces bank erosion, saves water, and educates the local school children about how to protect the earth we all share. The project was completed by SPAWN, the Salmon Protection and Watershed Network (www.SpawnUSA.org ), a community-based environmental non-profit in the San Geronimo Valley of Marin County, California. SPAWN's mission is to protect and restore creek and riparian habitat within the Lagunitas Creek Watershed and to protect and restore endangered coho salmon and steelhead. In 2003 SPAWN was funded through a 319(h) grant to develop citizen water-quality monitoring and nonpoint source pollution awareness outreach, and to implement an on-the-ground project to address nonpoint source pollution. This success story focuses on the rainwater catchment project completed by SPAWN in the summer of 2006.
Rainwater Catchment Project:
The Lagunitas School project was designed cooperatively with the Lagunitas School District, with input from the Regional Water Quality Control Board staff and others. Actual implementation of the project was accomplished by SPAWN staff, interns and volunteers, Lagunitas School Board member,, Richard Sloan, Lagunitas Organic Garden Coordinator, Josh Traub, and a pro-bono crew of local contractors. The project was completed in August 2006.
The model project captures rainfall from the roof of a 1,600 sq. ft. playground lunch-shelter at the local Lagunitas Elementary School in the San Geronimo Valley, diverting it away from a stormdrain and into a cistern during the stormy winter months. The project serves to irrigate the School's Organic Garden Project during the dry, summer period.
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The first step was to install a new 1,600 sq. ft. polycarbonate roof on the school's outdoor lunch-shelter. The slanted roof leads to a rain gutter where two downspouts collect water into one pipe that flows to a new "Pioneer Galaxy" 30,000-gallon cistern adjacent to the school garden. In an average year, the roof drains 35,000 gallons of water. 30,000 gallons of that water can be stored in the cistern and used during dry months to water the school's garden, where kale, snow peas, cabbage, broccoli, chard, sweet peas and other vegetables are grown for educational and school cooking projects. The additional 5,000 gallons of water is diverted through and overflow into a nearby raingarden (vegetated swale) where it is allowed to filter into the groundwater table.
Left un-captured, the roof's runoff would have drained onto a concrete pad and into a 10-inch storm-drain that empties out onto an already eroded bank on Larsen Creek, a salmon-bearing creek that flows into San Geronimo Creek, one of the major tributaries to Lagunitas Creek. Although small in size, in most years, Larsen Creek is home to more coho salmon spawners than the entire Russian River basin!
SPAWN's future goals are to leverage this project to encourage a heightened awareness of stormwater issues related to impervious surfaces on the School District property, and to implement further projects at both the school and other facilities. Since the project was completed in August 2006, it has already received local press coverage and has garnered widespread community interest. During the winter months, hundreds of visitors on our creek walks visit the project. The project is certainly highly visible and we hope to use it in future years as part of science school curricula (calculating rainfall, runoff from roofs and parking lots, and associated physical principles) and a watershed tour to demonstrate methods in creek care, sustainable water-use and stormwater runoff mitigation.
More Project Info:
This roofwater catchment project was achieved through a larger program of SPAWN's 2003 319(h) (Clean Water Act) grant program. Our overall 319h goals were: 1) to contribute to the development and implementation of TMDLs through a citizen-based water quality monitoring program, 2) to identify sources of nonpoint source pollution by surveying stream habitat, assessing potential sources, and mobilizing an "Emergency Response Team" as needed, 3) to educate the public about nonpoint source pollution, and 4) to complete a replicable, community-based restoration project designed to reduce stormwater runoff and sediment loads into creeks and to increase groundwater recharge. Hence the Lagunitas School roofwater catchment project!
Watershed Background and Relevance:
Lagunitas Creek and its tributaries, located in western Marin County (north of San Francisco), drains into Tomales Bay, an estuary of national significance. The Lagunitas Creek Watershed has been identified by State and Federal resource managers as one of the most important waterways left for wild coho salmon in Central California, and for steelhead populations as well. Coho salmon in this region are listed as "endangered" at both the State and Federal level. On average five hundred (500) spawning adult coho return yearly to the Lagunitas Creek Watershed, down ninety percent (90%) from historic levels. Factors leading to their precipitous decline include: elimination of more than half their historic spawning habitat as a result of Marin Municipal Water District dams built in the early 1900s; sedimentation of spawning habitat due to erosion from poor land-management practices and roads; impoundment of water needed for juvenile and adult salmonids; loss of floodplain and off-channel habitat as a result of development (roads, homes); and areas of poor water quality (e.g., high fecal coliform counts) likely a result of leaking septic tanks and other impacts from urbanization. Impervious surfaces from roofs, parking lots, driveways and roads also prevent water percolation into underground aquifers, causing more dangerous and frequent flooding that threatens lives and property. The increased velocity and volumes of storm water also increase soil erosion, damage creek banks and cause harmful sedimentation that harms salmon and other aquatic life. Lagunitas Creek and its tributaries have been 303(d) listed for sediments, nutrients, and pathogens, and TMDLs are scheduled for development in approximately 2008.