After a really good start, the lake is
currently at elevation 21.8 feet, typical for early May and consistent with
normal annual operations. However, because of recent dry conditions and
forecasts, and significantly earlier than normal snowmelt, Corps water managers
intend to complete refill by mid-May instead of the usual June 1 target date.
“If we wait until late May, there may not be
sufficient lake inflow to get us to elevation 22 feet,” said Ken Brettmann,
senior water manager with the Seattle District, U.S. Army Corps of Engineers.
Getting the lake to 22 feet is extremely
important since every inch of water in the 2-foot operating band is needed for
fish passage, lockages, and managing water quality throughout the season.
Refilling early last year helped immensely
during the record-breaking drought but Corps officials still needed to alter
lock operations. Even with the operational changes of the early refill, limiting
water usage for smolt flumes, maximizing lockage efficiency and delaying lockages,
the lake briefly fell below the 20 foot minimum elevation water managers try to
“Last year’s challenging drought conditions
reinforced how important it is to fill the lake to the 22 foot elevation each
year,” said Brettmann.
Depending on conditions, the lake may remain at
full pool through June. The official lake level is measured at the Locks. 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.
Vessel owners should closely monitor lake
elevations and adjust mooring lines as necessary.
More information on Lake Washington’s status is
available on the Corps’ Seattle District Reservoir Control Center website at http://bit.ly/NWS-RCC.
Release no. 16-012