SEATTLE -- Both large and small locks will close to all marine traffic eight hours, 8 a.m. to 4 p.m., September 18 to inspect and open a saltwater drain screen structure. The large lock will close again to all marine traffic eight hours, 8 a.m. to 4 p.m., September 19 for sill and pump discharge inspections in preparation for the large lock dewatering outage in October.
The structure, immediately upstream of the locks, prevents salmon from entering the locks’ saltwater return intake. Divers will open 10, 10-foot-by-6-foot doors and inspect the 30-by-60 foot curved-front, mesh screen structure. U.S. Army Corps of Engineers officials open the doors and inspect the structure annually after salmon migration season ends 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.
The saltwater drain delivers water to a diffuser beneath the fish ladder to provide flow for fish passage.
“We closed off some potential well access points and in 2008 installed the screen,” said Locks’ fisheries biologist Kaitlin Whitlock. “We continue to research ways to ensure salmon can pass upstream to spawning grounds.”
Another project projected to help with salmon migration is replacement of the large lock filling culvert valves. Original to the century-old locks, the valve gates open and close, allowing water to flow through the large tunnels to raise and lower levels in the chamber. The new gates will allow flow regulation that the old system does not.
The upgrade will require several extended 45-day closures to replace the filling culvert valves. The projected closure dates are:
2019
October 12 through December 3
2020
February 12 through April 5
October 12 through December 3
2021
February 12 through April 5
November 9 through November 24
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.