The city of Kent will close 104th Avenue Southeast between Southeast 267th Street and Southeast 272nd Street from Monday, June 10 through this fall for work on the Upper Mill Creek Dam.
Traffic will be diverted to 108th Avenue Southeast, according to the city Public Works Department.
A $5.9 million city project to improve the Upper Mill Creek Dam will help reduce flooding and restore salmon populations. The City Council unanimously approved a low bid in August 2018 by Aberdeen-based Quigg Bros. Inc., to raise the height of the dam by about 5 feet along the east side of 104th Avenue Southeast near Southeast 267th Avenue, according to city documents. Crews will add a reinforced concrete wall to the top of the dam to increase flood storage by about 50 percent and install a fish ladder.
The project will help control flooding downstream in Mill Creek, including 76th Avenue South and Woodford Avenue. The dam provides flood risk reduction in the area spanning from Earthworks Park to Central Avenue and from Titus Street to James Street. The area includes the Kent Senior Activity Center, Mill Creek Middle School and a number of homes and businesses along Mill Creek.
The city will pay for the project from its storm drainage fund. Residential rates are $12.81 per month for the storm drainage fee. Commercial businesses and multi-family complexes pay a fee based on impervious surfaces.
Fish passage is included in the project to comply with environmental permitting requirements from the state Department of Fisheries, the U.S. Army Corps of Engineers and from consultation with the Muckleshoot Indian Tribe, according to Public Works staff. The original dam and flow diversion structure does not have a formal fish ladder facility.
Crews built the dam in 1974. The dam was upgraded to its current structure in 1989. The improvements will increase flood storage to about 150 acre feet or 49 million gallons.
In addition to improving the dam, the city plans to dredge Mill Creek in 2020 to reduce flooding in the Kent Valley – an estimated $10 million project.