Utility company Seattle City Light has announced its plan to rehabilitate to spillway gates at the Gorge Dam in Newhalem this summer, requiring water levels in Gorge Lake to be lowered for the work.
The rehabilitation will be coordinated by Long Painting of Kent, Wash., and includes seal replacement and recoating of all surfaces on two 47-foot by 50-foot steel gates. Seattle City Light said the work will require the removal and replacement of backing plates and the replacement of approximately 1,000 bolts, with all work needed to be complete by October 1 to ensure the Gorge Dam’s availability as part of the Skagit River flood control program.
“This work has been scheduled for several years as a necessary step to ensure the long-term reliability of these gates,” said Mike Haynes, Seattle City Light Director of Power Generation. “Summertime represents the most favorable conditions for performing this work due to the need for predictable weather and worker safety.”
The utility said it will lower the water level in Gorge Lake over a three day period, beginning July 15. The lake is to be returned to its normal operating level when work is completed in September.
The current Gorge Dam was built in the 1960s and helps provide water to the Gorge Powerhouse, located two miles upstream. The 175-MW hydroelectric plant was completed in 1924 when the original Gorge Dam was a wooden crib structure and provides about 9% of Seattle City Light’s overall generating capacity.
HydroWorld.com reported in April that Seattle City Light had been recognized by The Climate Registry as “Climate Registered” for the second consecutive year. The utility became the nation’s first to achieve carbon-neutral status in 2005.