State environmental review of proposed Chehalis River Basin Flood Damage Reduction Project
The Chehalis River Basin Flood Control Zone District has proposed constructing a flood retention dam and associated temporary reservoir on the Chehalis River near Pe Ell, and making changes to the Chehalis-Centralia Airport levee.
Ecology released a draft state Environmental Impact Statement (EIS) and analyzed how the proposal is likely to affect the environment under the State Environmental Policy Act (SEPA). More detail is below and Ecology’s focus sheet has an overview of the findings of the draft EIS.
A comment period for the draft state environmental review of the proposed Chehalis River Basin Flood Damage Reduction Project was held from February 27 to May 27, 2020. Public meetings were held in April to present information about the report and receive verbal comments. The presentation on the draft EIS is available as slides or with audio. Next, Ecology will consider the comments and responses will be included in the final EIS, expected to be released in spring 2021.
Comments on the draft EIS are available to view and download. All comments are valued equally. They have been arranged in categories solely for ease of access and downloading. Tribal comments. Agency comments. Business comments. Public comments. Organizational comments. Public meeting comments. Form letter comments.
Flood District’s proposed project
The Flood District’s flood retention dam and associated temporary reservoir is intended to reduce damages from major floods from Pe Ell to Centralia triggered by rainfall in the Willapa Hills. The Airport levee changes would raise and widen the Chehalis-Centralia Airport levee and nearby roads to improve the levee protection level during catastrophic floods. The project is not intended to address flooding in all parts of the Chehalis River basin and would not stop regular annual flooding.
Relationship to Chehalis Basin Strategy
Communities in the basin are working with the Chehalis Basin Board on a long-term strategy to reduce flood damage and restore aquatic habitat. One part of this strategy is to consider large-scale flood damage reduction actions. The project evaluated in the draft environmental review is one of the proposed actions for consideration. The Chehalis Basin Board is expected to use the information in the environmental review, along with other information, to inform their recommendations for the long-term strategy.
Study identifies significant environmental impacts
Ecology’s review studied the likely significant environmental impacts from the Flood District’s project as well as alternatives. Ecology looked at 17 different environmental elements including impacts to air quality, cultural resources, environmental health and safety, environmental justice, fish and aquatic species, habitat and land use, recreation, transportation, tribal resources, water, wetlands, and wildlife.
Under Ecology’s analysis, the project would reduce flooding to buildings and infrastructure, including U.S. Interstate 5. It would have significant adverse effects, mainly along the Chehalis River in the area above the flood retention dam and below the structure to Rainbow Falls. These include:
- Reducing spring- and fall-run Chinook salmon, Coho salmon, and steelhead trout
- Reducing native aquatic species such as lamprey and mussels
- Reducing wildlife such as amphibians
- Degrading habitat on land, and in water and wetlands
- Degrading river and stream water quality
- Eliminating access for recreational fishing and whitewater boating
- Increasing greenhouse gas emissions
- Impacting tribal and cultural resources
Several impacts from the proposal would be unavoidable unless measures to offset them are determined to be feasible and meet regulatory requirements. This would be determined during future permitting processes including local and tribal governments, and state and federal agencies.
Should the project move forward, there are nearly 40 local, state, and federal authorizations, approvals, and permits that would be needed.
EIS analysis integrates climate change
Since climate change will drive more frequent, higher flood levels, and steeper declines in fish runs in the Chehalis River basin in the future, Ecology integrated climate change in their analysis of future conditions where the proposed flood retention dam would operate.
Project alternatives analyzed
In addition to the proposed project, the EIS also analyzed what is known as a “no action” alternative. This examines what would happen if the flood retention facility is not built or no improvements are made to the airport levee. The study also analyzed an alternative based on localized and nonstructural actions that could help retain flood waters and reduce flood-related damage.
Summary available of state EIS scoping
Scoping is the first step in the state and federal environmental review process. From Sept. 28 through Oct. 29, 2018, Ecology and the Corps of Engineers held a joint SEPA-NEPA EIS scoping period—including two public hearings—to receive input regarding the scope of the state EIS. The SEPA EIS Scoping Summary Report provides a summary of scoping comments and outreach.
To ensure equal access to materials, Ecology will provide auxiliary aids/services to persons with disabilities. Please call (360) 407-6831 with any requests. Persons with hearing loss and speech disability can contact 711 for the Washington Relay Service. Persons with a speech disability may call TTY at (877) 833-6341. All meeting-related requests must be received 72 hours in advance.
El Departamento de Ecología del Estado de Washington (Ecología) determinó que el Proyecto Propuesto podría tener impactos ambientales adversos y significativos. El Borrador de la Declaración del Impacto Ambiental (EIS por sus siglas en inglés) identifica y analiza cómo es probable que el Proyecto Propuesto afecte el medio ambiente. Ecología ha preparado un borrador de EIS bajo los requisitos de la Ley Estatal de Política Ambiental (SEPA) en el Código Administrativo de Washington 197-11. Una EIS SEPA no aprueba ni niega un proyecto propuesto. Proporciona información sobre los impactos ambientales probables, significativos, y adversos, de una propuesta.
Ecología está solicitando comentarios públicos para el borrador de la EIS SEPA sobre el Proyecto Propuesto del 27 de febrero al 27 de mayo de 2020. Los comentarios recibidos sobre el borrador de la EIS SEPA durante el período de comentarios serán compilados y revisados por Ecología. Se considerarán comentarios sustantivos en la preparación de la versión finalizada de la EIS SEPA.