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Important work along Snoqualmie River will protect state highway, regional trail


Repairing the Sinnema Quaale structure protects a state highway, fiber optic line and a King County regional trail from the Snoqualmie River's erosive forces.


Work is expected to begin the first week of June to repair a damaged structure thatFlood Control Zone District Logo protects a state highway, a fiber optic line, and a King County regional trail from the erosive force of the Snoqualmie River north of Carnation.

Rebuilding the Sinnema Quaale Upper Revetment requires a summer-long closure of a stretch of the Snoqualmie Valley Trail.

The revetment – which absorbs and deflects the Snoqualmie River’s erosive energy  – has been repeatedly damaged by flooding beginning in 2006, and is in need of repair to restore its function.

Any further damage to the revetment would threaten public safety by potentially impacting State Route 203 – the primary transportation thoroughfare through the Snoqualmie Valley. A nearby fiber optic cable line is also threatened by further erosion.

In the past, the ongoing bank erosion and settling has repeatedly required King County Parks to close this portion of the Snoqualmie Valley Trail on short notice for emergency repairs; this repair should eliminate the need for these temporary short notice closures.

Located along the Snoqualmie River between Duvall and Carnation, the project includes reconstructing about 750 feet of bank revetment, and rebuilding approximately 1,100 feet of the adjacent trail. The $6.3 million project is being funded primarily by the King County Flood Control District, with King County Parks providing funding for rebuilding the trail.

While the construction is underway, a stretch of the Snoqualmie Valley Trail will be closed to all use from approximately 1-½ miles south of Northeast 124th Street to 2 miles north of the Stillwater Natural Area.

The trail closure is expected to run from June 1 to Oct. 31, and no trail detour is available. Trail users are encouraged to take advantage of other portions of King County Parks’ 175-mile regional trail system.

In addition to improving protection for the state highway, regional trail and a regional fiber optic trunk line, this project will benefit the local ecology by removing the remains of at least 20 rusted 1940s car bodies that were used as a cheap and convenient levee-building material at this site, and are the reason that this location on the Snoqualmie River is locally known to some as “Car Body Curve.”

The Sinnema Quaale Upper revetment is named after the property’s early settlers in this portion of the Snoqualmie Valley. The Sinnema (Dutch) and Quaale (Norwegian) families farmed the land dating back to the early 1900s – and their ancestors live in the area to this day.

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About the King County Flood Control District
The King County Flood Control District is a special purpose government created to provide funding and policy oversight for flood protection projects and programs in King County.  The Flood Control District’s Board is composed of the members of the King County Council. The Water and Land Resources Division of the King County Department of Natural Resources and Parks develops and implements the approved flood protection projects and programs. Information is available at

About King County Parks
King County Parks - Your Big Backyard - offers more than 200 parks and 28,000 acres of open space, including such regional treasures as Marymoor Park and Cougar Mountain Regional Wildland Park, 175 miles of regional trails, 215 miles of backcountry trails and a world-class aquatic center. By cultivating strong relationships with non-profit, corporate and community partners, King County Parks enhances park amenities while reducing costs.