The City of Kirkland improved native fish habitat and reduced flooding risks along a fish-bearing stream by replacing an aging culvert that allows the creek to pass under one of the city’s busiest arterials. The new culvert on 100th Avenue Northeast and improvements to Cedar Creek were designed by Stantec—a global engineering, architecture, and consulting firm. The firm’s Bellevue office managed the project.
“As a high priority with the City, this project removes the most significant fish barrier on Cedar Creek,” said Tim Nightengale, one of Stantec’s Bellevue-based project biologists. “The improvements open up significant habitat to migratory anadromous fish upstream of this location and will improve the overall health of Cedar Creek.”
The project restored native fish access to more than a mile of upstream habitat by removing the 40-year-old barrier. The improvements rebuilt 1,200 feet of the severely degraded creek channel, recreating a sinuous alignment with 23 log structures, bank stabilizing plantings, and deep pools. A new side channel allows larger flows to spread across the adjacent wetland and minimize downstream flooding.
The $2.5 million project replaced the original 36-inch concrete box culvert, which was structurally deficient and too small, with a culvert that is 14 feet wide, 10 feet tall and 120 feet long. To accomplish the work, crews bypassed the existing creek, excavated 100th Avenue Northeast down to the creek bed, and rebuilt the arterial to meet the needs for a future roadway widening project.
“It’s exciting to see the restored Cedar Creek flowing through the new culvert,” said Jim McPherson, Stantec project manager, based in Bellevue. “The more natural channel will support the return of fish to this waterway. Improving and restoring aquatic habitat is a priority for both the community and the state.”
Critical to the project’s success was its 23-day road closure. Stantec, Interwest Construction, and the City of Kirkland collaborated to limit traffic disruption.
“Twenty-three days is a long time to shut down one of your city’s busiest arterials,” said Laura Drake, the City of Kirkland project engineer, who co-managed the project. “But tight coordination between Stantec, Interwest, and the City of Kirkland helped us keep the community informed of the closure and the need for it.”
Stantec provided project management; civil design; biological design; structural design; and environmental permitting, mitigation, restoration design and construction inspection. Stantec’s Pacific Northwest design and environmental experts include more than 360 professionals. The firm has completed nearly 100 fish passage projects in the Pacific Northwest, including 14 that are injunction-compliant in Washington.