Flood Protection Project
We are working to protect our basin both now and well into our future.
The District is sponsoring a project that would support its goals of reducing flood risk, preserving life, preventing property damage, and protecting natural resources. The project has two related parts:
- 1 Flood retention facility
- 2 Improvements to the airport levee
Understanding the Flood Protection Project
Part 1: Flood Retention Facility
The facility would be located south of SR 6 in Lewis County, on the mainstem Chehalis River at approximately River Mile (RM) 108, about 1 mile south of (upstream of) Pe Ell. During major floods, which are expected to occur every 5-7 years, the facility will store water in a temporary reservoir and slowly release it back to the river as conditions return to normal. There will be no permanent storage for water, so in non-flood times, the river and its fish would move at their natural rate through outlets in the facility.
Part 2: Improvements to the airport levee
The District is proposing to increase the height of the existing levee by four to seven feet. Additionally, 1,700 feet of Airport Road would be raised to meet the new levee height along the southern side of the airport.
What are the benefits of the project?
The project would help protect basin communities from flood damage, reducing the duration and extent of severe flooding for many areas downstream. It would:
- Cause no net loss of habitat function for fish and other aquatic species.
- Reduce floodwater levels on over 4,000 acres.
- Decrease flood damages to structures by up to 72%.
- Reduce the likelihood and duration of I-5 and airport closures.
- Save hundreds of millions of dollars by reducing damages to structures, farms, and businesses and preventing transportation interruptions.(Early estimates show savings of more than $240 million per major flood event!)
What does “no net loss” mean?
“No net loss” means maintaining the same level of habitat function that exists in the basin today. Studies show that the District’s flood protection project can be built with no net loss of habitat function for fish and other aquatic species. The District has pledged to make no net loss a condition of construction and will meet this goal by conducting mitigation projects.
Federal and state agencies will review the District’s environmental mitigation plan. If approved, this means that all other habitat restoration work in the basin will have a net positive benefit for fish and other aquatic species.
How would the project affect the environment?
Visit our environmental review page to learn more and read the draft Environmental Impact Statements from the Washington Department of Ecology and the United States Army Corps of Engineers.Learn More