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Crews respond as manhole in Bothell overflows during record rainfall


Record rainfall March 16 resulted in a manhole overflow south of Thrasher's Corner in Bothell.


Record rainfall March 16 resulted in a manhole overflow south of Thrasher’s Corner in Bothell. The manhole, located in a wetland area away from residences, also overflowed during severe rain storms March 5-9.

King County Wastewater Treatment Division employees responded immediately to an overflow alarm at about 8 p.m. Sunday evening. The manhole is in a wetland west of the Bothell-Everett Highway between 208th Street Southeast (SR-524) and 214th Street Southeast.

While the system is now operating normally, an undetermined amount of highly diluted wastewater overflowed for up to four hours from the manhole on the North Creek Interceptor. King County reported the overflow to health and regulatory agencies and will sample and monitor water quality in North Creek over the next few days.

The interceptor is a major regional sewer line that carries wastewater collected from homes and businesses in unincorporated Snohomish County and the City of Bothell for treatment at the Brightwater Treatment Plant north of Woodinville. The County is completing design on a project to upgrade the line in this portion of the service area to provide additional capacity for homes and businesses and to ensure safe and reliable operations for decades to come. Construction on the project is expected to receive notice to proceed this year.

In 2013, King County conducted maintenance and repair activities to reduce stormwater entering the sewer system until the new project is completed.

According to the Seattle Weather Blog, 1.09 inches of rain fell on Seattle Sunday breaking previous mark of 0.98 inches from 1950. Seattle is only 0.72 inches away from breaking the mark for all-time wettest March ever.

Detailed information about the project, including maps, is available at For more information, please contact David Freed at 206-263-9453 or Monica van der Vieren at 206-263-7301, or 711 TTY.

This release is also posted on the website for the Department of Natural Resources and Parks at

Note to editors and reporters: Visit the WTD Newsroom, a portal to information for the news media about the Wastewater Treatment Division, King County Department of Natural Resources and Parks: