Yakima County and city officials have been working to remake the narrow gap between Selah Ridge and the Cowiche Upland for years in an effort to create better wildlife habitats along the Naches River and prevent floodwaters from reaching urban areas.
The projects involve navigating overlapping waterways, infrastructure and jurisdictions to reduce flood risk, improve natural habitat and better serve the community.
County and city officials will take the next steps in that process after receiving almost $11 million in federal funds to work on the Cowiche Creek Confluence Project – restoring the floodplain and addressing flooding where Cowiche Creek meets the Naches River over the next four years.
“The creek has been so modified for years to accommodate other infrastructure,” said Troy Havens, water resources division manager for Yakima County.
“By returning the Cowiche to that natural state, we’ll make big improvements,” said Mike Shane, the City of Yakima’s Water and irrigation Manager.
This batch of federal funding will go toward restoring Cowiche Creek between U.S. Highway 12 and the Naches River. Around half of the funds will go toward the Nelson Phase II Pipeline, which brings irrigation water from the new Nelson diversion to the City of Yakima.
What makes the improvements tricky is the overlap of roads, canals and boundaries in a narrow space between two dramatic ridges. Projects and updates need to happen on coordinated schedules to make sure new infrastructure fits together in a delicate jigsaw puzzle of water, concrete and riparian habitat.
Building that new pipeline will make older canals and diversions near the confluence unnecessary, allowing their removal and habitat restoration, Havens said.
The Cowiche Creek Confluence Project will bring restored habitat to the area, with a particular focus on the land between U.S. 12 and the Naches River.
Kory Graafstra, a natural resources specialist with Yakima County, said the Cowiche Creek bed would be returned to a more natural channel, eliminating sharp turns and diversions.
The county has bought much of the land near the confluence and orchards and irrigation infrastructure will be removed in the next few years, Graafstra added. New wetlands and riparian habitat with side channels cutting through them would create more space for fish and wildlife and make fish passage easier.
Bull trout and steelhead, both listed as threatened under the Endangered Species Act, could be in line to benefit as fish screens and piping are removed. That could bring more fish up Cowiche Creek.
Havens said parts of the restored habitat could also be publicly accessible. Planning is still in progress, but a park could be added to the area.
“We want to try to connect to the Greenway in some fashion,” Havens said.
Those connections are key to Yakima County Commissioner Amanda McKinney, who said the project addressed multiple needs. Not only did it improve habitat, she said, it created opportunities for recreation and efficient irrigation.
“It’s something we want to be mindful of. We want people to be able to get down to the river,” she said.
McKinney highlighted the collaboration involved in securing federal funding and working in the confluence.
Initial applications for federal funding were denied, she said, but county officials spoke with U.S. Bureau of Reclamation staff to solve those issues.
Reducing flood risk
The drive for much of this work came from 2016 and 2017, when flooding hit the Yakima area.
In 2017, Wide Hollow Creek topped its banks and Cowiche Creek burst through a levee, sending floodwater over 40th Avenue and as far as 16th Avenue, Havens said.
Various agencies came together to plan around the numerous pieces of infrastructure and housing developments that sit next to the Naches River in the narrow gap between ridges, Havens said.
Right now, Yakima County and the City of Yakima are collaborating to build a new levee between U.S. 12 and Powerhouse Road. That levee will replace an older levee that broke in 2017.
In the long term, reducing flood risk could lead to lower insurance costs for people in the current flood plain. Havens said removing people from flood risk maps drawn by the Federal Emergency Management Agency (FEMA) could mean instant savings for them.
That will take time, he cautioned, and involves working with the Federal Emergency Management Agency to reassess the local floodplain when more work is completed.
Eventually, Havens said, officials are hoping to widen the U.S. 12 bridge over Cowiche Creek, which will allow more water to flow under it and greatly reduce flood risk.
Brian White, a regional administrator for the Washington State Department of Transportation, said past floods have eroded U.S. 12’s embankment in the area and replacing the bridge would represent a solution to flooding.
There is no current project to replace the bridge, White said, but WSDOT is supporting efforts to minimize flooding.
