Our Views: Skookumchuck Dam Has Attention of the Chehalis Basin Board


The Skookumchuck Dam was built in 1970 to create a reservoir of water for one purpose: supplying water to the Centralia Steam Plant. 

With the plant scheduled to close in 2025, the dam’s purpose no longer exists. The dam blocks 30 miles or more of potential salmon and steelhead upstream. It is not designed to provide flood protection. 

The Skookumchuck river provides the most important spring salmon spawning habitat in the Chehalis Basin. Today, nearly 50% of the spring Chinook spawners in the basin spawn in the Skookumchuck. Less than 3% of the basin’s spring Chinook spawn in the upper main stem of the Chehalis River where the proposed water retention flood facility is proposed.                                                                                                                                                          

The Chehalis Basin Board has voted unanimously to move forward promptly to engage with the dam’s owner, TransAlta, to determine if the company will allow a serious look at whether the dam can be operated in a way to enhance salmon and steelhead spawning as well as provide winter flood storage.

In most years, the reservoir behind the dam is full by early November. After that, when a storm hits, the excess water spills over the dam, meaning that the dam provides no downstream flood protection to Bucoda, Centralia or other downstream communities.

There are many unanswered questions. 

Can the dam be modified to allow passage by salmon and steelhead or can they be assisted to get above the dam to spawn? Can the dam be operated or modified to provide any predictable downstream flood protection? Can dam modifications be done at a reasonable price? What would happen if the dam was removed?

Would that provide enough fish benefit to justify the costs? Could the Skookumchuck Dam operation, modification or removal be an important component of an overall basinwide fish enhancement and flood protection effort? 

Each year, the dam produces a small amount of electricity, but not enough to cover the cost of operation. What will happen to replace the electricity if the dam is removed?

All of these questions are on the table and need to be answered.

What we know is that the purpose for which the dam was constructed no longer exists. We know that it blocks salmon migration and potential habitat. And it does not provide predictable flood protection.    

We know that the dam’s owner, TransAlta, is closing its local operation. And we know that a plan needs to be developed soon to determine what happens to the Skookumchuck Dam.

The Office of Chehalis Basin Board includes both tribal members and representatives of other communities in the Chehalis Basin as well as agricultural and environmental representatives.  The fact that this diverse group has accomplished so much together including agreeing to this new look at the Skookumchuck dam is very encouraging. 

We applaud the Office of Chehalis Basin and its board for moving promptly to get answers.