Act Now:
Please consider contacting the Chelan County PUD Commissioners regarding the future of Tumwater Dam. Written comments can be submitted by email to the commissioners at:
garry.arseneault@chelanpud.org
Background:
Chelan County PUD’s plans to conduct an expensive repair on Tumwater Dam in 2023. An article published in the Wenatchee World on March 15 states the repairs are estimated to cost between 2.5 and 4 million dollars. Before moving forward, NCWAS requests that the PUD thoroughly assess the continued environmental and financial costs of keeping the aging dam in place.
Specifically, NCWAS requests the PUD conduct rigorous studies to examine the following:
- Fish migration — Currently, migration delays and impacts are only measured by salmon that choose to enter the fish ladder, and then fall back. The PUD needs to quantify migration delays and impacts of fish holding at the base (tailrace) of the dam prior to entering the fish ladder. During migration periods, fish can be observed attempting and failing to jump over the spillway of the dam. Currently, there is no understanding how many fish are injured, killed, or simply turn back downstream. The result is the same: we don’t currently understand the extent to which the dam may be delaying or inhibiting upstream migration into high-quality habitat. Three species of Endangered Species Act salmonids migrate over Tumwater Dam during their lives. Pacific lamprey passage at the dam is known to be problematic. Other native fish species also migrate up and down Tumwater Canyon throughout their lives and may be impacted.
- Water quality — Water quality impacts of Tumwater Dam have not been assessed but are likely occurring. NCWAS is particularly concerned about water temperature. The Wenatchee River is listed as having impaired water temperatures on the Department of Ecology’s 303d list. The water impounded above Tumwater Dam is unshaded, likely contributing to the elevated water temperatures during summer months. The salmonid species that call the Wenatchee River home depend on cold water, and the river’s elevated water temperatures jeopardize their continued survival. The Norwest Stream Temperature model (https://www.fs.fed.us/rm/boise/AWAE/projects/NorWeST.html) predicts the Wenatchee River will warm 2-4 degrees Celsius by 2080.
- Fish management practices – NCWAS understands that the dam’s current, and only, function as a fish management tool is highly valued by fisheries and hatchery managers. However, NCWAS is also aware that other, less impactful, options are available and widely used to accomplish the same tasks. Feasibility studies of alternative management options are needed to properly evaluate the need and cost of continuing to maintain this aging dam.
Other potential Talking Points:
- Historical and future costs — Over the past 20 years, Chelan PUD has spent over $3 million repairing the dam, and plans to spend an additional $2-4 million in 2023. Can the costs of maintaining the dam be redirected to dam removal and construction of a weir for fish management?
- Risk to transportation and commerce — In 2008, Washington Department of Transportation commissioned a study to evaluate chronic road maintenance issues along Highway 2 through Tumwater Canyon, stating that the dam directed flows at the highway and caused reoccurring washouts.
- Recreation — Tumwater Canyon has become a popular whitewater destination and boater advocates have stated that the dam degrades the recreational quality of the Wenatchee River.
Supporting Documents: