The design plans to replace an aging culvert at 100th Avenue Northeast in Kirkland have recently been submitted to the U.S. Army Corps of Engineers for permitting on the $1 million project.
The project would improve fish passage and reduce flooding in Cedar Creek by replacing the aging culvert.
The original Cedar Creek 36-inch concrete box culvert is structurally degraded and was built 30 years ago in 1989, according to Jim McPherson, Stantec project manager. Stantec — an engineering, architecture and consulting firm — is helping the city of Kirkland design and build the new culvert in a way that minimizes impacts on traffic flow, McPherson said.
The city and the design team are working on concepts to either maintain traffic flows on a diverted path, or to accelerate the planned work with closing the road and using a detour around this stretch of 100th Avenue Northeast, he said.
The current size and orientation of the culvert blocks fish passage, making it difficult for traveling salmon. And high-flow events and high-water velocity, because of culvert conditions, have caused an eroded downstream channel. Upstream is an outdated storm-detention structure, with no adequate flow control. This prevents sediment transport.
The project aims to tackle these issues, while reducing the risk of flooding.
“By working with the city of Kirkland, we have an opportunity to restore a key stretch of Cedar Creek,” McPherson said in a press release. “The project will bring back a more natural channel and provide a longer path for flow than currently exists. That will allow natural vegetation to come back. Supporting aquatic habitat is a priority within the community and within the state. This project supports that goal, providing the best return on investment to the city of Kirkland.”
The city of Kirkland is planning to begin construction next summer, with plans for the project to be completed by October 2020.