The sunshine has been a treat for most of the early spring and summer, but it also has an adverse effect: with such little rainfall, Lake Washington’s water level could drop below 20 feet this summer, and boaters will experience delays at the Ballard Locks. According to the U.S. Army Corps of Engineers officials, current forecasts say the lake could have record-low levels by August, and could continue to drop until September or October. The last time the lake levels were that low was October 1987.

The Corps says they typically maintain the water level between 20 and 22 feet, officially measured at the Chittenden Locks. Officials keep winter levels at 20 feet, and begin the annual summer refill in February, targeting a 22-foot refill by late May to early June. They say the higher level helps meet summer water use, providing water necessary for fish passage, navigation and salinity control.

The Corps anticipated the low levels, and took precautionary steps to speed up the annual refill. They say the lake reached a 21.95 foot elevation in early May this year, but low inflows means the lake level is still dropping faster than normal, already nearing what is normal for mid-summer levels at just above 21 feet.

Boat traffic through the locks will begin to experience longer delays, as the Corps will start maximizing lockage efficiency by increasing the number of recreational vessels in each locking and adding more recreational vessels with commercial vessels. “By increasing the number of vessels for each locking, recreational vessels could experience up to one hour delays waiting for additional vessels to arrive,” the Corps says.

The Corps has taken a number of conservation steps, including limiting the amount of water used to operate the juvenile salmon flumes used to provide smolt safe passage into the Puget Sound. Normally the Corps uses four flumes, but they’ve reduced it to one in order to save water. The Corps is also asking floating-home owners to prepare for low water levels of 18.5 to 19 feet.

“Water management is about balance,” said Seattle District Senior Water Manager Ken Brettmann, who oversees reservoir regulation at the Corps’ Western Washington projects. “This year will be extremely challenging and we’re balancing water conservation across lines to minimize impact to commerce, fish and the public.”