The Proposed Chehalis River Dam
In 2020, The Chehalis River Basin Flood Control Zone District (FCZD), proposed construction of a new dam in the Chehalis River. The Chehalis River is a key water way for the salmon, specifically Chinook salmon, Coho salmon, and Steelhead salmon, which are critical components of the southern residential killer whales’ (SRKW) diet.
The proposed function of this dam is to help prevent flood damage. It would operate by allowing regular flow of water, however, when water levels get too high threatening a flood, the flood gates would close and retain water until it could all be safely let out.
In the earliest stages of this project, the Washington State Department of Ecology published an environmental impact report, which showed many negative environmental impacts. A brief rundown of these impacts include:
-Projections that 123,439 metric tons of greenhouse gas (GHG) emissions produced from construction.
-Construction could affect archeological sites; also, traditional and cultural sites could be affected.
-Permanently altering 0.32 acres of the river channel.
-Small chance of reservoir failure in the event of an earthquake, that would result in damage to people, infrastructure, and the environment. (Environmental justice would become disproportionate.)
-Smaller salmon runs.
-Temporary and permanent removal of vegetation affecting up to 847 acres of land.
-Changes in water temperature.
-Eliminating many acres of wetlands.
-Decreased wetland habitat function.
It’s been five years since this report came out, and design changes have been incorporated to minimize the negative impacts. The updated environmental impact report will be available in the fall of 2025. Design changes include:
-Fish conduits that would mimic natural river conditions that fish could pass through.
-Realigning the dam on the river so that it could affect less area of cultural significance to the Confederated Tribes of the Chehalis Reservation.
-Reducing the size of the reservoir by 32 acres to reduce vegetation impacted during the construction of the dam.
-Updated spillway design.
The salmon may not adapt well to this environmental change. The proposed changes to the salmon passage could be detrimental to their run sizes and populations. One of the biggest factors contributing to the endangerment of SRKWs is lack of food, and smaller salmon runs will greatly reduce the already too small salmon populations available for the orcas. SRKWs are critically endangered with just 73 left, and this dam could be harmful to the restoration and conservation of this endangered species.
There are many ways you can make your voice heard if you want to help stop this dam. There are Chehalis basin board meetings once per month, happening on the first Thursday of each month, where you can make a comment to the board. Also, when the new environmental impact report is published in the fall of 2025, you will be able to write in and make a comment on that.
My Resources
https://ecology.wa.gov/getattachment/1c1097b9-e746-480b-bf07-120d5128ed11/Chehalis-SEPA-DEIS-Summary-022720.pdf
http://chehalisriverbasinfczd.com/
https://officeofchehalisbasin.com/get-involved/
https://www.orcaconservancy.org/blog/action-alert-stop-the-proposed-dam-on-the-chehalis-river
https://www.orcanetwork.org/action-advocacy/blog-post-title-one-9c996-cc3ht
https://www.fisheries.noaa.gov/west-coast/endangered-species-conservation/saving-southern-resident-killer-whales#:~:text=The%20research%20identifies%20three%20main,These%20factors%20compound%20each%20other.