Meadowbrook Pond is located east of 35th Ave NE at about NE 107th Street, its entrance framed by the flame ash street trees which line the arterial. The pond is part of a low-lying flat area called the Confluence because the North and South Branches of Thornton Creek combine here.
At the Confluence there is high groundwater and periodic flooding. For that reason, Meadowbrook Pond was created for flood management and for filtering sediments in the water.
Flowing out of Meadowbrook Pond, the water continues to Matthews Beach and into Lake Washington. Sediments, if carried downstream, would silt up the outlet of the creek at Matthews Beach and then the water would back up and cause flooding. Filtering sediments out of the water at Meadowbrook Pond helps prevent flooding downstream.
The Thornton Creek system flows from Shoreline and northeast Seattle through eighteen miles of tributaries. It might have been named for Washington Territory pioneer John Thornton though he didn’t live in Seattle.
Since its creation in 1996-98 Meadowbrook Pond has worked so well to collect and filter the water, that the pond has needed more frequent maintenance than originally planned. The pond is currently in a three-year cycle of improvements.
Dredging was done in 2012 and in the summer of 2013 the pond was enlarged at its northwest corner to increase its capacity to hold water. Other work done in summer 2013 was for improving access by maintenance crews. For example, there is a trash rack (vertical structure to catch debris) and this year the walkway was improved for greater safety of access by crews who clear the trash rack. Another improvement put in was paved access ramps for vacuum trucks which remove sediment from the pond.
Landscaping work will continue into the months of October and November, which is the best time of year to plant trees.
More information is available on the Seattle Public Utilities page with updates for Meadowbrook Pond and The Confluence.
The Confluence area and 35th Ave NE culvert improvements were constructed in 2014, completing this three-year cycle of work.
In 2015 work was completed to create a bridge in a section of the roadway of 35th Ave NE so that instead of being culverted, the creek flows freely underneath the roadway. This is better for fish and also will help to reduce flooding by creating more space for water to spread out. Along with the road work in 2015, a much larger floodplain was created on the east side of 35th Ave NE which is for more capacity for water.
UPDATE: Construction fencing was removed on Friday, October 4, 2013 and on that weekend many people enjoyed being able to stroll in the Pond grounds once again. There is still a lot of work to be done in landscaping and tree-planting, and the area will look more “finished” as new ground cover and trees grow up in the spring.
IMPORTANT NOTICE: A warning has been posted about dangerous levels of bacteria in the waters of the Thornton Creek Watershed. Do not allow children to play in creek water or in the Meadowbrook Pond, and it is advised that dogs should not drink the water, either. Scroll to the end of the report page to read the Microbial Trace Study of June 2013 by Dr. Jonathan Frodge.