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GREEN INFRASTRUCTURE ASSETS
The 8th Avenue "Industrial Strength" natural drainage site is a great example of stormwater management in an area without any 'gray' curb and gutter infrastructure. 8th Avenue is one of Seattle's oldest streets, and has a 100-foot right-of-way. Until 1937, the right-of-way once held the original "light rail" in Seattle: the Des Moines-Seattle streetcar line, connecting Seattle to the southern neighbors of South Park, Boulevard Park, and Des Moines. When the streetcar tracks were ripped up in 1937, the 57-foot right-of-way became an enormous dirt 'parking strip' with giant potholes. Eventually, after 80 years on the site, Markey decided to pave their driveways over the dirt shoulder, which initiated the project's need to problem-solve how to deal with stormwater running off of impervious surfaces on a street without any stormwater service.

The three swales do not drain into any piped infrastructure, but are designed to hold and infiltrate stormwater that runs down the Markey concrete driveways. The plant pallet is a combination of Pacific Northwest species and other plants that love water in winter and are drought-tolerant in summer.

Rain Garden, Workplace, Bioswale

Green Infrastructure Systems and Functions:
Hydrologic System
Social System

DESCRIPTION
8th Avenue is a busy industrial and trucking/shipping hub. In the summer it's dry and dusty and in the winter the street is full of puddles. Some say the puddles are tidally influenced from the Duwamish estuary, a mere 2 blocks away. The street connects the Georgetown historic neighborhood with a wonderful shoreline street-end pocket park on the Duwamish, called Gateway park. People from the residential and industrial neighborhood use the park during the days and evenings. Twice a year people from the community host work parties to pick up trash, remove invasive blackberry vines, and plant native species.
There is a decommissioned pump station at the street end that used to pump water from the Duwamish up to the Georgetown Steam Plant to generate electricity for the street cars and breweries in the area around the early 1900s. The community would like the pump station to be used to display historic murals about the local Native American and early settler histories.

PHOTOS AND DRAWINGS

Cross-section of the swale. Design: Amalia Leighton, SvR for Seattle Department of Transportation

LESSONS LEARNED
This project was lead by community and business stakeholders. Luckily the project had a very persistent project manager within the City of Seattle's Department of Transportation, who helped work the project from inside the City. This project would have been nearly impossible for a volunteer community group or a business initiating this on their own because it attempted to set a precedent for the City, prior to the new drainage code being written. Internal City staff were critical to the project's success as well. The fact that the site is also within a few blocks of the Duwamish River Superfund site, as well as a known hazardous waste emitter (up the street), we had difficulties getting he project going in the beginning. We were also cobbling together small lumps of funding to pay for the design of the swale, the landscape design, construction, paving, materials, and project coordination (Neighborhood Street Funds (SDOT), Neighborhood Matching Fund (DON), Puget Soundkeeper Alliance settlement funds, business contributions, volunteer hours, and other materials).

The most exciting success for the project is that the Vice President of an industrial business, a neighborhood volunteer group, non-profit staff, and government staff worked together, meeting for several years to slowly bring the project along. Individuals formed positive working relationships with each other, and there is a high likelihood that a future iteration of the working group could partner on other projects in the area.

As far as maintenance, the working group will use "light duty" staff from the neighboring industrial businesses to keep the swales free of trash and weeds. Yearly work parties will also help keep the swales functioning properly; at some point the bottoms of the swales may need to be dug out again.

The "Industrial Strength" natural drainage swales, in addition to the overall site improvements that Markey recently completed, make the site the nicest looking industrial site in Seattle!

ADDITIONAL RESOURCES
Link to the Duwamish River Cleanup Coalition web site.