Work has begun to remove an obsolete levee on the Rainbow Bend reach of the Cedar River.

Rainbow Bend is a three-quarter-mile-long segment of the Cedar River east of Renton, near the intersection of Cedar Grove Road and State Route 169.

This work is the final phase of a three-phase project that began in 2006, to reduce flood risks to homes and private property, to state Route 169, and to King County’s Cedar River Trail.

Removing the old, degraded levee will allow floodwaters to pass safely across the floodplain and reduce flood velocities by about 30 percent for a 100-year flood event. The project is also intended to improve fish and wildlife habitat by allowing the river to widen and create side channels and slow water areas where fish can take refuge during flooding.

Project construction includes about four weeks of in-water work that will take place between July 1 and Aug. 31, in the time of year that is known as the fish window – when fish protected by the Endangered Species Act are not present.

The in-river work will limit recreational access in the river, including possible full closure for brief durations when intensive construction is under way. Signs will be posted and the project website will be updated to alert users as construction progresses.

Funding for this phase of the project is being provided by the King County Flood District and Seattle Public Utilities. Total construction cost for this phase is approximately $1.25 million.

For more information, visit the project website at www.kingcounty.gov/rivers, or contact Jon Hansen, environmental scientist, at 206-296-1966.