State environmental review: Proposed Chehalis River Basin Flood Damage Reduction Project

The Chehalis River Basin Flood Control Zone District (District) is seeking to construct a flood retention facility and associated temporary reservoir near the Lewis County town of Pe Ell, and make levee and other improvements around the Chehalis-Centralia Airport.
We have determined the District’s proposed Chehalis River Basin Flood Damage Reduction Project could have significant adverse environmental impacts.
We are now conducting an environmental review of the proposal under the State Environmental Policy Act (SEPA). We are currently preparing a state draft Environmental Impact Statement (EIS) that will identify and analyze how the proposal is likely to affect the environment. The state’s draft EIS is planned to be released in February 2020.
In addition, the U.S. Army Corps of Engineers (USACE), is also conducting a separate but synchronized federal review of the District's proposal under the National Environmental Policy Act.

Project description and intent clarified

The District has developed a detailed description of its proposed flood damage reduction project, including supporting documents. In response to questions we and the USACE posed, the District also provided clarifications regarding the project.

For example, the District made clear the proposed flood retention facility and associated temporary reservoir is intended to reduce damages from periodic floods from Pe Ell to Centralia triggered by rainfall in the Willapa Hills. The project is not intended to address flooding in all parts of the Chehalis River basin.

Different environmental elements to be evaluated

The state EIS will study the likely significant environmental impacts from the proposed project as well as project alternatives. Our SEPA analysis will include climate change as we evaluate how the project could affect the following:
  • Air quality
  • Amphibians
  • Cultural resources, both historic and archaeological
  • Cumulative impacts
  • Environmental health and safety
  • Environmental justice
  • Fish
  • Geology and geomorphology (landslides and earthquakes)
  • Habitat and vegetation
  • Land use
  • Noise
  • Public services and utilities
  • Recreation
  • Transportation
  • Tribal resources
  • Visual
  • Water
  • Wetlands
  • Wildlife (including impacts to southern resident killer whales)

Geographic study area could vary

The geographic area we intend to study could vary, depending where probable significant impacts are likely to occur. In general, the study area will be:
  • The site of the proposed flood retention facility site near Pe Ell.
  • Upriver and downriver where probable impacts could occur.
  • The area near the Chehalis-Centralia Airport levee
The study will look at the entire life-cycle of salmon and analyze impacts to chinook salmon that could affect southern Puget Sound resident orcas.

Project alternatives to be analyzed

Besides the proposed project, the EIS also will analyze what is known as a "no action" alternative. This examines what would happen if the flood retention facility is not built or no improvements made to the airport levee. The study will also analyze an alternative based on localized and nonstructural actions that could help retain flood waters and reduce flood-related damage.

Click to see full map.

State EIS scoping completed, summary available

Scoping is the first step in the state and federal environmental review process. We and USACE held a joint SEPA-NEPA EIS scoping period from Sept. 28 through Oct. 29, 2018 — including conducting two public scoping meetings. During scoping, the public as well as representatives from local and tribal governments, state and federal agencies, the business community, and other organizations provided input regarding the scope of the state EIS.
The comments we heard help identify project alternatives, likely significant adverse impacts, and potential measures to offset negative environmental effects. We will consider the substantive scoping comments we received as we develop the state draft EIS.
The SEPA EIS Scoping Summary Report provides a summary of scoping comments and outreach. This report will be included in the SEPA draft EIS as well. Visit the EIS Scoping page to view scoping materials and other information.

Administrative and SEPA process questions

What is SEPA? Why are Environmental Impact Statements being done for the proposed Chehalis basin project? Who decides what the Environmental Impact Statements will evaluate? What is a substantive scoping comment? Does it matter how many times a comment is made? Where can I find a response to my scoping comment? Will comments at meetings be more valued? I made a comment on the programmatic EIS for the Chehalis basin. Will it be automatically included?