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Thornton Creek Confluence & Meadowbrook Pond Project

  • Local construction impacts
  • King County Metro bus route changes
  • Thornton Creek Confluence project area and future improvements

Thornton Creek is 18 miles of urban creeks and tributaries flowing from Shoreline through northeast Seattle into Lake Washington at Matthews Beach Park. The creek is the largest watershed in Seattle, draining a 12-square-mile region of relatively dense biodiversity for an urban setting and home to over 200,000 people.

Thornton Creek provides habitat for many species of fish, including endangered salmon and trout. View more information on migratory fish (pdf).

The North and South Branches of Thornton Creek combine just upstream of Meadowbrook Pond, in a flat area called the Thornton Creek Confluence. The Confluence lies within the area bordered by Northeast 105th Street on the south, Northeast 109th on the north, from just west of 35th Avenue Northeast to 39th Avenue Northeast.

At the Confluence, high groundwater has significantly contributed to the wetlands and saturated soils that occupied this site historically. In more recent years, significant flooding has affected a number of homes and occasionally closed 35th Ave. N.E.

Seattle Public Utilities is improving the Thornton Creek Confluence to reduce upstream flooding and downstream flows. The Thornton Creek Confluence project will also provide:

  • A new 2.0-acre floodplain and meandering channel for the existing creek.
  • Construction of a new culvert under 35th Ave. N.E.
  • Improved wildlife habitat with native riparian plantings.
  • Removal of invasive plants on the stream bank.

Construction is anticipated to begin in May 2014 and take approximately six months to complete. During construction, anticipated temporary impacts will include:

  • Closure of 35th Ave N.E. with pedestrian and Metro bus re-routes. Advance detour information will be provided.
  • Noise and machinery in the project area. Please stay clear of moving trucks and heavy equipment and keep out of fenced areas.
  • Restricted access to Meadowbrook Pond from 36th Ave N.E. The Pond will remain open and accessible from the east, west and south.
  • Removal of approximately 108 existing trees, including 11 street trees on 35th Ave N.E. More than 600 new trees will be planted as part of the project.

Overall, this project will help restore water quality, improve fish and wildlife habitat, reduce local flooding, and prepare for other flood reduction projects in the future. 

View the latest project updates for Thornton Creek Confluence, or sign up to receive the latest updates via email.

Meadowbrook Pond is a SPU-created facility near 35th Ave N.E., between N.E. 105th and 107th streets, across from the Meadowbrook Community Center. It serves two distinct functions: (1) flood management on Thornton Creek and (2) a place for fine sediments in the water to deposit, which improves the water quality. The Meadowbrook Pond maintenance improvements were completed in 2013 and the Pond was reopened in October 2013 following four months of construction.

Related Links

Lake Washington Watershed
Thornton Creek Water Quality Channel