Learning More About Watersheds

Threats to our watersheds-threats to us

Everything we do or don't do on the surface of our natural watershed "sinks" impacts our water quality. Our actions also affect the rate that the water flows. Like organs in a body, every part of a watershed is essential. What affects one part, affects all parts.

The results of what we do in our homes and on our land can extend hundreds of miles downstream. As we go about the business of our lives, each of us impacts the watershed day by day, drop by drop.

1% of H2O is all we have

When rain falls it begins a never-ending cycle. It evaporates or percolates underground or flows along waterways into Puget Sound and the ocean. There it evaporates, forms clouds and falls to earth again.

The water we currently have on this planet is all we will ever have. Ninety-seven percent of the earth's water is contained in the oceans and 2% is frozen. That leaves only 1% as fresh water we can use.

The Major Watersheds:

The Snohomish-Snoqualmie Watershed

The Snohomish-Snoqualmie Watershed covers nearly 700 square miles of land and is home to about 45,000 people. While the Snoqualmie River is in King County, it is part of the larger Snohomish River Watershed that flows into Puget Sound at Everett.

While the Snohomish-Snoqualmie area is well known for its farms, which lie downstream of Snoqualmie Falls, much of the Snohomish-Snoqualmie watershed is forested.

Chinook, coho, pink and chum salmon and steelhead trout spawn in the Snohomish-Snoqualmie. The tributaries of the Snoqualmie produce more coho salmon than the entire state of Oregon.

"Within the last ten years, amphibians have been declining globally
- They are telling us something about our environment"

- Klaus Richter, King County Senior Ecologist

The Cedar-Sammamish (Greater Lake Washington) Watershed

The Greater Lake Washington watershed covers a vast area including two of the largest lakes in the state (Lakes Washington and Sammamish), two major river systems (Cedar and Sammamish) and a vital connection to the saltwater environment through the Ballard Locks.

The Cedar River supplies two thirds of Seattle's drinking water and contributes more than half of the fresh water to Lake Washington.

Both lakes are popular for boating, swimming and water skiing, and are lined with waterfront homes, parks and businesses. Native runs of chinook, kokanee (a landlocked salmon species), steelhead, coho and sockeye inhabit and use portions of these waters, making the Greater Lake Washington watershed unique in metropolitan areas.

The Green-Duwamish Watershed

The Green-Duwamish watershed, originally 1,600 square miles, is only 492 square miles today because the Cedar River was diverted to Lake Washington and the White River to the Puyallup River in the early 1900's. The main stem of the Green River stretches 90 miles from the heavily industrialized Elliott Bay to the pristine Cascade Mountains.

More than 400,000 people live in the watershed, home to commercial forestry, farming, international trade and industry.

Despite the loss of almost all the tidal wetlands at the mouth of the Duwamish River and significant loss of habitat, all five species of Pacific salmon are found here, with coho and threatened chinook predominating.

When we take care of our watersheds, they take care of us.

Additional Resources

• Rivers and Watersheds
• Snohomish-Snoqualmie Watershed
• Cedar-Lake Washington Watershed
• Sammamish Watershed
• Green-Duwamish Watershed
• White River Watershed
• Central Puget Sound Watershed