Ongoing maintenance on the Round Butte Dam will keep levels of Lake Billy Chinook noticeably lower than normal until mid-April, prompting a warning to boaters who frequent the popular recreation area.

The Oregon Parks and Recreation Department is advising boaters that the current water level and lowered docks could cause boats to make contact with rocks and debris.

Boat ramps at Cove Palisades State Park will still be accessible, but park staff warn that drop-off points may be exposed. Longer wait times may occur as boaters exercise caution while loading and unloading boats.

Dam maintenance is conducted by Portland General Electric and the Confederated Tribes of Warm Springs, co-owners of the Pelton Round Butte dam complex. The complex, which includes three dams along 20 miles of the Deschutes River, was completed in 1964 and generates enough power for 150,000 homes.

Drawing down the water level began in September to allow for spillway maintenance at Round Butte Dam.

Maintenance includes replacing three turbine shut-off valves that control the flow of water from the reservoir through the dam and into the turbines, said Allison Dobscha, a spokesperson for Portland General Electric. Each valve is 15.5 feet in diameter and weighs approximately 120 tons. The valve gallery is located at the lowest level of the plant powerhouse and is about 35 feet below the lower river level.

“The existing valves are original to the dam construction and have been in constant use since 1964,” said Dobscha. “After 60 years, the valves need to be replaced to improve their function and reliability.”

To replace the turbine shut-off valves, the Round Butte plant will temporarily pause power generation, and all water flowing from the reservoir will be redirected through the spillway.

While the water is redirected, the old valves will be removed and replaced. New wiring, hydraulics and electronic controls will also be also be installed.

Portland General Electric will start refilling the reservoir when the dam repairs are complete and anticipates Lake Billy Chinook will reach regular summer levels no later than June 5.

The power authority said the change in water level has no impact on water quality, fish or wildlife populations in the reservoir.

Lake Billy Chinook pumping project moves forward as North Unit tries to overcome water shortage