TULALIP – Stormwater runoff from the parking lots and playfield at Tulalip Elementary runs directly into Tulalip Bay. Traveling through conventional drains and pipes, at times seeping over the sidewalk onto Totem Beach Road, the water potentially picks up and carries pollutants.
At the nearby Boys and Girls Club, the lack of drainage results in a parking lot pond when it rains.
As an alternative to conventional stormwater detention methods, the Tulalip Tribes are turning to low impact development (LID) to improve water quality and fix several drainage problems. The tribes’ Natural Resources Department is engineering wetlands to absorb stormwater and filter out pollutants before it drains into the bay.
“For fish it’s much better to address your stormwater naturally as it would happen without us,” said Val Streeter, stormwater planner for the tribes. “So that’s why we’re getting away from the conventional stormwater treatment – pipes, curbs, gutters, detention ponds – and moving into more natural treatment, where you don’t disturb the land as much and try to mimic nature to the greatest extent possible.”
Concern about water pollution in Tulalip Bay has grown because of the increasing population in the surrounding area. Potential contaminants in stormwater runoff include dissolved metals, such as copper shavings from car brake pads. Even in trace amounts, copper can be fatal to juvenile salmon. It interferes with their alarm pheromones, making them vulnerable to predators. It also impairs salmon’s breathing, brain function and sense of smell, interferes with migration and depresses the immune system.
Like a natural wetland, an engineered wetland has habitat value, but its primary function is absorbing and breaking down pollutants carried by stormwater.
“What an artificial wetland does is hold water, similar to a storm detention pond except you have much more soil and vegetation that you use in order to filter the water,” said Julia Gold, environmental planner for the tribes. “It’s a very slow process, you need enough volume to hold whatever stormwater runs off your parking lot. Then the water will essentially move through that wetland.”
This summer, the tribes’ Natural Resources Department plans to install two catch basins in the Boys and Girls Club parking lot, to drain into a constructed wetland adjacent to an existing natural wetland. Below the playfield, an existing natural wetland will be enhanced and drainage will be improved to prevent water from flooding onto Totem Beach Road. Additional engineered wetlands will treat water from the school parking lots and improve absorption of pollutants from the runoff.
“The wetland will act like a filter to clean metals and pollutants from the water,” Streeter said. “We will construct an initial settling pond so that pollution can settle out, then we’ll add soils with high organic content – microbes that break down pollution plus soil to trap and hold metals. Last, you add your plants and at the end of the pond you have your outlet. Assuming the water sits long enough, it will come out clean.”
Low impact development techniques already have been successfully used at Tulalip’s beda?chelh (Beh-Daa-Cha) Behavioral Health Department and Health Clinic. The beda?chelh parking lot has permeable pavement and the Health Clinic site uses biofiltration in addition to conventional underground water detention.
“Beyond our environmental stewardship, Tulalip Bay is important to the tribe for economic and cultural reasons,” said Tulalip Chairman Mel Sheldon. “As we evaluate and plan from the water quality studies that have been done up to this point, we’re also looking at what actions we can take right now to clean up the bay.”
The projects also are an opportunity to involve students in natural resources stewardship.”We want to involve students from Tulalip Elementary and Northwest Indian College, perhaps in planning, monitoring water quality or comparing water quality before and after filtration,” Gold said. “The project gives them an opportunity to learn about stormwater and impacts on water quality.”
The Tulalip Tribes Board of Directors in early November approved planning and engineering for the project. The planned wetlands are being funded through a combination of grant money from the U.S. Environmental Protection Agency’s Clean Water Act Fund and tribal hard dollars. Construction is planned for the summer, with wetland planting beginning in early 2010.
“The Watershed Plan by our Natural Resources Department staff, continuous water quality monitoring and community support are all essential to ensure our number one priority – a clean Tulalip Bay for the Tulalip Tribes and our surrounding community,” said Harvey Eastman, the manager of the Water Quality Department for the Tulalip Tribes.
For more information, contact: Mytyl Hernandez, Tulalip Tribes Public Affairs, (360) 716-4013 or [email protected]; Kari Neumeyer, NWIFC information officer, (360) 424-8226 or [email protected].
