The rain and cooler temperatures of the week of September 21 to 27, 2014, were a signal to fish, that it is almost time for them to swim upstream!  The summer dry-season is over, and in-water work at The Confluence on Thornton Creek must finish by the end of September in compliance with state regulations on habitat for fish.

With creek work finishing now, construction will continue on the flood plain area being created on the east side of 35^th Ave NE adjacent to Meadowbrook Pond, and on rebuilding of the 35^th Ave NE roadbed. Westwater Construction is the private contractor working on this project designed by Seattle Public Utilities along 35^th Ave NE at NE 107^th Street in Meadowbrook.

In September 2014, from Meadowbrook Pond, we look to the northwest where a digging site for a flood plain will extend from 35th Ave NE eastward toward the Pond.

Meadowbrook Pond is not a “park” but is a Seattle Public Utilities facility with the functions of containing floodwaters and filtering sediments out of the water.  The sediments settle in the pond and are dredged out by vacuum trucks in a cycle of routine maintenance every few years.  As the creek then continues its flow eastward to its outlet on Lake Washington at Matthews Beach, excess sediments will not be carried along downstream, which would cause the creek and outlet to become silted up and blocked.

Both branches of Thornton Creek, north and south, were temporarily diverted during summer 2014 construction to improve and enlarge the creekbeds at the point of The Confluence where the creek branches join and flow into Meadowbrook Pond.  Seattle Public Utilities reported that recent rainfall which caused higher water in the creek, allowed observation of how newly-installed log structures and rock weirs are working.  In addition to improvement of fish habitat, creek improvements are designed to help sediments move through the channel into Meadowbrook Pond.

The South Branch of Thornton Creek flows eastward parallel to Nathan Hale High School and its athletic fields. Here we see new engineered log structures and rock weirs which improve habitat for fish and help move sediment along. The tarp areas will remain covered until new trees and ground cover can be planted in Autumn 2014.

Looking north on 35th Ave NE we see rebuilding of the roadbed at NE 107th Street where new, much larger culverts were put in to carry the south branch of Thornton Creek eastward to Meadowbrook Pond.

Work is progressing on-schedule at The Confluence site, including the continued closure of 35^th Ave NE at NE 107^th Street through the end of November 2014 while the roadway is rebuilt.  A huge cut was made across the road to install much larger culverts for the south branch of the creek to pass under 35^th Ave NE on its way to Meadowbrook Pond.  Now a bridge-like structure is still under construction to rebuild the roadway over the new culvert.

Extensive digging can still be seen on the east side of 35^th Ave NE at NE 107^th Street, where a flood plain is being created to increase the capacity for water even more.

Seattle Public Utilities Thornton Creek reports of the monitoring of the water quality can be found at this link.

Looking northward from Meadowbrook Pond, we see the fenced-end of 36th Ave NE. Extensive work will continue from September to November 2014 to create a flood plain here, which will flow into Meadowbrook Pond. Engineering solutions such as the flood plain and the Pond are intended to hold water and release it gradually rather than letting it rush and overflow along the Thornton Creek channel.