Thornton Creek Alliance
  welcomes you!

In Your Care!
Picture courtesy of

The Thornton Creek Alliance (TCA) is a grassroots, nonprofit organization dedicated to preserving and restoring an ecological balance in the Thornton Creek watershed. The Thornton Creek Alliance publishes the Thornton Creek Currents, a newsletter mailed directly to members' homes.

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Meetings/ Events

updated Apr 10, 2007

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Links of interest

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Restoration Projects

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Education  / Outreach /


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TCA's Newsletter, Currents


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Become a TCA Member

Our goal is to benefit the creek by encouraging individuals, schools, groups, businesses and government to work together to address the many issues associated with the creek system, including water quality, stabilization of water flow, flood prevention, reforestation, habitat improvement, stream-bank stabilization, open space acquisition, community involvement, and education. We also promote neighborhood-based monitoring and stewardship of Thornton Creek.

TheThornton Creek watershed is a drainage of approximately 11.6 square miles in northeast Seattle, and Shoreline.   It is Seattle's largest watershed, and drains to Lake Washington at Matthews Beach.  That water ultimately goes through the Lake Washington Ship Canal to Puget Sound. The creek is a historic home to at least 5 species of Pacific salmon and trout (with 3-4 salmon species, plus trout, still migrating each year.) 

Take a Tour of Thornton Creek

As an urban watershed, the Thornton Creek drainage has been impacted by development and its consequences--frequent flooding,sedimentation, pollutants, loss of biodiversity, and decimation of salmon runs and other aquatic life.

Do you know the seven pesticides to avoid? Thornton Creek is one of the King County Streams subject to the U.S. District court-ordered 60 foot buffers. Read more.

An interesting article on the impact of pet waste on creeks and other water bodies:

Report Surface Water Pollution
Help protect Seattle's water and wildlife by reporting surface water pollution. Seattle Public Utilities will send a surface water quality field inspector to investigate the problem and get it cleaned up.
Surface water refers to rain that falls and carries pollutants along streets and into Seattle's creeks, lakes and Puget Sound. Examples of pollutants to report so they can be cleaned up include:
leaking automobiles
concrete dumped on the street
paint poured down a drain
Use Surface Water Pollution On-line Complaint Form or call the Surface Water Pollution Report Line at (206) 684-7587. To make a report

P.O. Box 25690
Seattle, WA 98165-1190


Questions, comments:
Webmaster Christine L. Southwick

The Thornton Creek Alliance thanks Seattle Community Network for making this space available.