Due to low water levels in many Corps reservoirs in the Willamette Valley, officials are warning reservoir users of potential hazards.
The low levels, a result of low precipitation this fall, are exposing soft, muddy areas of lake bed, which could pose a danger to users. The surface of Green Peter Reservoir was at 904 feet above sea level, down roughly 106 feet from its full pool, on Nov. 26.
Due to these potential hazards, Corps officials request that reservoir users avoid these areas for their own safety.
The Corps will temporarily close areas when necessary to address safety concerns. Cottage Grove’s Lakeside boat ramp closed Nov. 19. Other reservoirs with potentially hazardous lake beds include Green Peter, Hills Creek, Lookout Point, Cottage Grove and Fall Creek. Closures will remain in effect until water levels return to normal.
Over the past 20 years, the record low pool was 899.1 feet on Oct. 30, 2015. This year, the record low was 902.25 feet on Nov. 23. On Monday, Dec. 3, after 1.25 inches of rain, the reservoir was at 915.13 feet. The lowest possible pool allowing the river to continue flowing is 745 feet.
Power from Willamette Valley dams primarily is used to stabilize the power grid.
The National Weather Service predicts more precipitation in the coming weeks, which may allow for better access to Corps reservoirs this winter.
“We’re hoping it rains some more,” said Corps Spokesman Tom Conning. The minimum pool for power production is 887 feet, and the target pool for this time of year and in the ideal world is about 934 feet.
The Willamette Valley consists of 13 Corps-operated dams and reservoirs that work as a system to provide flood risk management, recreation, water quality and supply and more to the region. Many factors impact water levels in the Willamette Valley’s lakes and reservoirs throughout the summer and fall, including the Willamette Biological Opinion – which focuses on meeting target flows for fish downstream.
Lack of inflows to those water bodies is another factor on which hydrologists base release decisions.