Stormwater & Toxics

I’ve been waiting for this. From the time I got into the river’s pristine headwaters, I was waiting for the Darth Vader of my journey. It’s time to swim through the Duwamish River’s toxic mess. This is the part of the river that scares people.

I found several storm drains pouring water into the Lower Duwamish. Some were carrying water that looked fine, but one was cloudy and smelled bad. I put my GoPro inside of one small storm drain and got an interesting video of the inside of the pipe. Finally, I came to the grand salon of the Duwamish Diagonal, the largest storm drain in Seattle. It has two entrances leading to a very large pipe. Big enough to swim inside…


…and so I swam into the storm drain. This is probably not recommended, but I couldn’t swim this far down the river and dodge away from the problems. See video at this link and below.

Toxics in the Lower Duwamish come from 2 sources.  Industrial dumping from past decades remains buried in the mud.  But the biggest source of new pollution is storm drains like the Duwamish Diagonal that bring polluted runoff into the river when rain falls and flows over oily roads and other hard surfaces.

Fortunately, King County and others are working to clean up polluted stormwater runoff, and you can help.

Storm drains and runoff are not the pretty part of the Duwamish and Green River.  But they’re reality, and an important part of the story.