Why does the water level of Lake Washington change through the year?

The Hiram M. Chittenden Locks are getting an upgrade.

After more than a 100 years of shuttling boats from Lake Washington to Puget Sound, the large lock will close for 45 days.

The U.S. Army Corps of Engineers is replacing the original valves, known as the Stony Gate Valves. The closure will impact larger commercial vessels.

The Ballard Locks are part of a much larger waterway system that includes Lake Washington.

KUOW listener Nancy Morrison was curious why the water levels in Lake Washington vary at different times of the year.

Our SoundQs team went to find out. Click on the play button above to hear the story!