Juneau Rain Garden Will Improve Jordan Creek Water Quality

 

Jordan Creek: An impaired fish stream

Jordan Creek, in the valley near the Juneau airport, is an anadromous stream that supports coho, pink, and chum salmon along with Dolly Varden char and cutthroat trout. Jordan Creek has been listed by the Alaska Department of Environmental Conservation as an impaired waterbody due to sediment, high turbidity, low dissolved oxygen, and debris attributed to urban runoff from the nearby streets and parking lots. Fine sediments and other pollutants attributed to urban runoff occurring in the densely populated lower portion of the watershed can adversely impact fish and fish habitat. 

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North side of the Edward K Thomas Building, looking east toward back parking lot. Note the sediment from melted snow. Vegetation not yet emerged. Photo taken April 2014.

 

Stormwater Pollution and Green Infrastructure Stormwater is the water that flows across our yards, streets, and parking lots after rainfall and snowmelt. In developed areas, stormwater picks up a variety of pollutants such as petroleum hydrocarbons, heavy metals, fertilizers, pesticides, fine sediment, and fecal matter, which it eventually discharges into our streams and waterways. Stormwater flow is traditionally managed using ditches and storm sewer systems designed to concentrate and quickly move water. Traditional stormwater infrastructure discharges directly into our streams with little time for pollutants to settle out. Green infrastructure uses vegetation and natural processes to manage and treat stormwater to minimize impacts on the environment. Examples of green infrastructure include rain gardens, bioswales, planter boxes and constructed wetlands. Green infrastructure options can be selected and designed to fit site-specific conditions. The Juneau Watershed Partnership and US Fish and Wildlife Service recently completed a stormwater inventory and assessment for the lower Jordan Creek watershed to identify opportunities to manage the quantity and quality of stormwater entering the stream.     

The Jordan Creek Green Infrastructure Project The Juneau Watershed Partnership, Southeast Alaska Watershed Coalition, and Central Council of Tlingit and Haida have partnered to construct a snow barrier fence and rain garden at the Edward K. Thomas Building in the Juneau Airport Shopping Center.  

Central Council of Tlingit and Haida’s property boundary for the Edward K Thomas Building located in the Airport Shopping Center in Juneau, Alaska.

Snow management activities in the Airport Shopping Center parking area frequently result in contaminated snow and snowmelt impacting the riparian habitat and discharging directly into the creek. This snow carries contaminates harmful to fish and wildlife and can destroy the riparian plants. To deter contaminated snow from being pushed into the riparian areas and stream, SAWC and JWP worked with project partners to construct a barrier fence along the perimeter of the parking area near Jordan Creek. The fence extends approximately 600 feet and consists of both split-rail cedar fencing and concrete barriers to prevent impacts from snow plows. 

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Volunteers help unload and stack cedar posts and rails for the split-rail snow fence
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Assembling the split-rail snow barrier fence

The next phase of the project will include construction and planting of a rain garden and bioswale to collect and filter stormwater from 36,000 square feet of parking lot area. The rain garden will be situated between Jordan Creek and the parking area intercepting the majority of the stormwater, and will contain substrate and native plants selected for their water retention and filtration properties. Rain garden construction is expected to be complete this fall, with planting occurring in the spring.

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Gretchen Pikul (ADEC) and John Hudson (USFWS) help plant willows to revegetate the riparian area

 

Learn more about how rain gardens work and why other Southeast Alaska communities are using them to improve water quality in their streams with Taiya Inlet Watershed Council’s Guide to Building Rain Gardens!

 

Funding for this project was provided by the Alaska Department of Environmental Conservation Alaska Clean Water Actions Grant Program, and the National Fish and Wildlife Foundation Wells Fargo Environmental Solutions for Communities Grant Program. Thank you to all of our partners and volunteers who have helped make this project possible!