The U.S. Army Corps of Engineers are set to raise lakes Washington and Union to the target summer elevation a couple of weeks earlier than normal due to extremely low inflows to Lake Washington.
The lake is currently at elevation 21.9 feet, which is typical for early May and consistent with normal annual operation.
However, due to the extreme low water supply situation (no mountain snow pack, dry recent conditions), the Corps intends to complete refill to an elevation of 22 feet in the next week or two instead of the normally scheduled June 1 target date. The official lake level is measured at the Ballard Locks.
“If we wait until late May, there probably won’t be sufficient lake inflow to get us to elevation 22 feet,” says Ken Brettmann, senior water manager with the Seattle District, U.S. Army Corps of Engineers.
“In a very poor water supply year like this one, getting the lake to 22 feet is extremely important, as every inch of water in the 2-foot operating band will be needed to operate the locks for fish passage, lockages, and managing water quality concerns this year given current and expected future low lake inflows,” Brettmann continues.
Lake Washington levels may vary due to the natural gradient between the lake and the locks or wind that can push the lake levels up for short durations. Depending on conditions, the lake may remain at full pool through June and July.
Vessel owners should closely monitor lake elevations and adjust mooring lines as necessary.
Click here to find out more information on Lake Washington’s status.