From U.S. Army Corps of Engineers

The Hiram M. Chittenden Locks in Ballard will close to all marine traffic 7 a.m. to 1 p.m., June 6, allowing U.S. Navy divers to inspect a saltwater drain screen structure.

The structure, immediately upstream of the locks, prevents salmon from entering the locks’ saltwater return intake. Navy divers from Naval Base Kitsap, will close 10, 10-foot-by-6-foot doors and inspect the 30-by-60 foot curved-front, mesh screen structure. The Navy annually supports the U.S. Army Corps of Engineers with this procedure 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 at least a week prior on the Seattle District’s public web site at http://bit.ly/BoaterInfo and on the Locks on Facebook and Twitter sites at www.facebook.com/chittendenlocks and http://twitter.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.

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