Both locks, large and small, will be closed for a few days the last week in January

From the Locks web site:

Repair on locks in Ballard will cause visitor, vessel traffic closures January 13, 2012

SEATTLE – The 95-year old Hiram M. Chittenden Locks are showing signs of wear and tear from nature’s most destructive force, and repair work beginning Friday will cause visitor and vessel traffic closures near the end of January.

Water has caused erosion along a portion of the small lock wall creating a scour. U.S. Army Corps of Engineers, Seattle District, officials said the lock is safe and there is no immediate danger of failure, but the repair is needed to maintain the safe waterway and stop further erosion.

“There have been scour problems documented in a nearby area for 30 years. The first major repair was done in 1985 to the apron,” said Marian Valentine, a hydraulic engineer in charge of operations and maintenance of the facility. “Water is very destructive so we actively monitor the locks and make interim repairs where necessary.”

A 2009 sonar survey detected an elongated scour hole and during a subsequent dive inspection, a void was noticed under the small lock foundation.

To repair the monolith, the Corps contracted Redside Construction, Port Gamble, Wash., for $1.3 million to drive sheet piles adjacent to the wall. These sheet piles will act as armor, to prevent future erosion, and as forms so concrete can be pumped in to fill the void. As part of the contract, riprap and quarry spalls will be placed in areas where channel scour occurred.

To minimize aquatic ecosystem harm, the Corps worked with state and federal agencies and scheduled work to coincide with U.S. Fish and Wildlife Service time restrictions. The Corps also prepared a Biological Evaluation in accordance with the Endangered Species Act to assure full compliance, according to Project Manager Joshua Jackson.

The work is expected to take 60 days to complete and the locks are likely to close to all visitor and vessel traffic for a couple days during the last week of January. For more information and updates follow the Chittenden Locks on www.facebook.com/chittendenlocks and www.twitter.com/chittendenlocks.