The structure, immediately upstream of the locks, prevents salmon from entering the locks’ saltwater return intake. Divers will close 10, 10-foot-by-6-foot doors and inspect the 30-by-60 foot curved-front, mesh screen structure. The U.S. Army Corps of Engineers closes the doors and inspects the structure annually before salmon migration season begins mid-June. Divers will perform monthly inspections until the doors are opened mid-September.
The inspections require Lock closure to all but emergency vessels on emergency calls. The staff will complete work as quickly and safely as possible. Monthly inspection closures will be posted on the Seattle District’s public web site at http://bit.ly/BoaterInfo and on the Locks on Facebook site at www.facebook.com/chittendenlocks.
Prior to installation of the large screen structure in 2008, adult salmon sometimes entered a diffuser well beneath the fish ladder. The well does not have an exit and entering it led to salmon migration delay, injury or death. The saltwater drain structure improves viability of salmon using the fish ladder returning upstream to spawning grounds.
The Chittenden Locks fish ladder was one of the first in the nation. Former Seattle District Engineer Maj. Hiram M. Chittenden understood salmon’s importance to the Pacific Northwest ecosystem and incorporated a fish ladder in the Locks early 1900s design. In 1976, Corps officials renovated and improved the ladder to reflect changes in fish conservation.
For more information about activities at the Locks, visit the Locks’ Web site at http://bit.ly/BallardLocks. Also follow the Locks on Facebook and Twitter, http://twitter.com/ChittendenLocks.
Release no. 16-021