Lower Monumental Dam’s navigation lock near Kahlotus will be out of service April 21 for repairs.
An August inspection found cracks in the lifting mechanism of one of the two valves used to fill the lock. The lock has continued to be used, but having just one valve operating has doubled the time needed to fill the lock, according to the Army Corps.
Repairs started earlier this month and should finish in May, with most of the work not requiring taking the lock out of service.
The visitor center at the Lower Granite Dam near Pomeroy also is closed through April 22. The access road to the center is being used for heavy equipment for work on a new juvenile fish bypass system.