Rainbow Bend on the Cedar River was the site of an ambitions levee removal and floodplain restoration project that provided flood risk reduction benefits and restored salmon habitat.
The project’s first stage included buying a flood-prone mobile home park and nine single-family homes subject to repeated flooding, and helping to relocate the residents. The next stage involved removing a degraded 900-foot levee, digging pilot channels across the floodplain, and placing logs in the floodplain to slow water velocity and provide habitat diversity when the river moves through the floodplain.
Removing the levee reconnected 40 acres of river floodplain, significantly improving conditions for young salmon on their way to the ocean, as well as for adult salmon migrating upstream. The project also eliminated the flood risk to more than 50 families in the 100-year floodplain and allows floodwaters to dissipate, easing flood risk to residents downstream, and reducing impacts to the Cedar River Trail, State Route 169, and a regional fiber optic cable line. Post-project monitoring after only two years showed that the number of young Chinook salmon that can live in the river at Rainbow Bend has roughly doubled. A patchwork of new habitat is developing and more change is expected.
Funding Sources:
- City of Seattle
- Federal Emergency Management Agency
- National Oceanic and Atmospheric Administration’s Pacific Coastal Salmon Recovery Fund
- King County
- King County Flood Control District
- King County Conservation Futures
- King Conservation District
- Puget Sound Acquisition and Restoration Fund
- Salmon Recovery Funding Board
Congressional District: 8
Partners:
- King County
- City of Seattle
