LAKE UNION The effect of this natural system will have an overall impact of cleaning the lake by reducing contaminants by 4%.
Fairview Ave
WATER RUNS FROM HIGH POINTS TO LOW Runoff from the Capitol Hill drainage basin naturally flows towards the South Lake Union Neighborhood.
Republican St SWALE
SOUTH LAKE UNION
CASCADE NEIGHBORHOOD
North Dexter
Valley St
Yale Ave East Lake Ave
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Harrison St Thomas St
CAPITOL HILL
Swales remove 60% of contamination
Denny Way Pontius Ave
VEGETATION NATURALLY CLEANSES STORMWATER Particulates and chemicals in rain waterrunoff can be treated without mechanical means through planted channels called bioswales.
188 million gallons of Capitol Hill runoff will flow through the swales. convention center
et ark em lac eP Pik
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WHERE IS IT?
SEATTLE, SOUTH LAKE UNION AND CASCADE NEIGHBORHOOD PROBLEM
SOLUTION:
Stormwater from Capitol Hill flows across streets and surfaces collecting particles and contamination before the 475 acres (188 million gallons per year) of runoff head to the storm drain pipe that empties into to Lake Union. This process contaminates the lake with silt, heavy metals, fertilizers, and pathogens that affect plant and animal habitat as well as human conditions. Typical stormwater treatment plants designed to remove these pollutants are expensive and unattractive interruptions to the urban environment.
Stormwater will be treated through a vegetated filter called a bioswale, an earth channel planted with erosion resistant and flood tolerant grasses, that removes contaminants collected in Capitol Hill while creating a neighborhood amenity in Cascade and improving the water quality conditions of Lake Union. This win-win situation takes advantage of new development to meet rising infrastructure demands of associated hardscape through a less invasive and more cost effective means. Stormwater from below ground pipes will be pumped into four street-level bioswales that will naturally treat 188 million gallons of stormwater every year.