Nooksack Levee Project Shows Success of Floodplains by Design

By Jenny Baker, Senior Restoration Manager

Thanksgiving Day floods found many people evacuating their homes around Puget Sound and fish searching for quiet places to get away from fast-moving floodwaters. Two of the 29 projects funded by Floodplains by Design provided just that: flood refugia for salmon behind log jams and in off-channel areas constructed as part of these multi-benefit projects. 

  During the Thanksgiving Day flood, log jams provided quiet places for fish away from the waist-high standing waves through this section of Canyon creek. Photo © Paula Harris   

During the Thanksgiving Day flood, log jams provided quiet places for fish away from the waist-high standing waves through this section of Canyon creek. Photo © Paula Harris
 

Canyon Creek, which is a tributary to the Nooksack River, is a high-gradient, high-energy creek that had been constricted by a levee along the right bank. In 1989 and 1990, several homes were completely destroyed by debris flows, and additional creekside homes were threatened as fast-moving water eroded the banks. Fish also struggled to pass through the firehose of water.

The first phase of the project removed homes that were at risk of being washed away, and then the levee was set back, reconnecting the creek with its historic floodplain and channel migration area. Log jams were installed throughout the reach to reduce stream energy and form pools for migrating salmon. 

 Canyon Creek project during construction in 2013. Photo © TNC

During the Thanksgiving flood, Paula Harris, Whatcom County Flood Manager, was on site to see how the project was performing.

"You could hear the boulders crashing against each other. The standing waves were waist high, but the water around the logs jams was tranquil — a nice place to be if you were a fish in this creek."

These quiet off-channel floodplain habitats provided places for fish away from the rushing river. Photo © Paula Harris

The Deming levee setback project is located on a fast-moving portion of the main stem Nooksack River. The project involved constructing a new setback levee that provides protection for the town of Deming against much larger floods than the previous levee. On Thanksgiving, floodwaters backed up into the reconnected tributary, providing a place along the fast-moving river where fish could find refuge in the quiet, off-channel habitat.

The project also reconnects off-channel habitat for juvenile salmon, which is especially important during floods. And it is a step forward in building relationships for larger-scale actions in the Nooksack floodplain. 

The NOAA Restoration Center also contributed funds to the Deming levee project.

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