Reporter for The Canyon Weekly
The U.S. Army Corps of Engineers has produced a tentative plan for solving fish passage and water temperature issues in the Willamette River Basin.
The Corps has released a draft environmental impact statement for a program that would affect all 13 Willamette reservoirs, including Detroit Lake.
The 2,000-plus page document was released Nov. 30 and will undergo a public comment period that lasts through Jan. 19. See the information box on page 7 for instructions on how to participate as well as local zoom and in-person meetings.
The Corps has been working to resolve fish passage and water temperature issues since 2008, when a National Marine Fisheries Service “biological opinion” concluded that the continued operation and maintenance of the Willamette dams “was insufficient to avoid jeopardizing the continued existence” of endangered chinook and steelhead stocks.
The Corps is under a court order to take action to improve threatened winter steelhead and spring Chinook salmon stocks in the Willamette basin and the new EIS is intended to be a response to the court order.
The long-delayed and long-analyzed project is going through a bit of a reboot. Instead of Corps officials working specifically on the Detroit piece, the new EIS reflects a broader initiative that will cover the entire 13-dam Willamette River Basin.
Earlier work on the Detroit piece included consideration of building a massive tower near the dam to address the water temperature issue and a giant weir to move fish around the dam. Such structures also are in the revised plan, but it is not clear how their use or implementation differs from previous iterations.
The process is of keen interest in the Santiam Canyon because of the tourism value of Detroit Lake.
If solutions to the fish passage/temperature challenges require lowering the lake level, the region’s economy will suffer.
The Corps considered a no-action alternative as well as seven other alternatives, with the draft EIS identifying Alternative 5 as the preferred course of action. Alternative 5 is described as the “refined integrative management flexibility and ESA-listed fish alternative.”
The proposal is intended to improve conditions for ESA-listed fish while providing flexibility for USACE to meet water demands for fish and wildlife, water supply, hydropower generation and recreation. The EIS says the Corps can meet project goals with Alternative 5 “using a combination of modified operations and structural improvements, along with other measures to balance water management flexibility and meet ESA-listed fish obligations.”
The earlier approach with the tower and the weir also was reviewed by the Corps as Alternative 4. It was noted in the draft EIS that Alternative 4 would be “the costliest alternative to implement” at more than $110 million per year. This high cost, the report said, “make it unlikely this alternative would be acceptable to many stakeholders, agencies and the public.”
The Corps timeline for Alternative 5 at Detroit calls for a temperature control tower to be completed by 2031 and downstream fish passage work to be completed by 2035.
PLAN OBJECTIVES
• Greater flexibility in water management (refill, drawdown timing, etc.).
•. Nature-based structures that help prevent bank erosion.
• Greater flexibility in hydropower production.
• Increase ESA-listed fish passage survival at dams.
• Improve water management during the conservation season to benefit ESA-listed fish and other purposes.
• Improve water quality to benefit ESA-listed species.
• Reduce spawning and rearing habitat competition caused by hatchery fish
