By Lindsay Peyton 

The Hiram M. Chittenden Locks in Ballard are closed for regular maintenance. 

No marine traffic has been able to traverse the large lock since Monday, Nov. 6 – but the small lock remains available for vessels less than 120 ft. in length and 26 feet in width.Closing the area for upkeep is essential to preserving the natural ecosystem – and to keep traffic flowing, William Dowell, spokesman for the Seattle District of the U.S. Army Corps of Engineers, said. Every year, Dowell said, the Army Corps of Engineers consults with area businesses to determine the best time for the project. Usually, November is ideal, when business is slightly slower. 

This year, with the recent installation of new pumps, Dowell the process is going faster. Instead of three weeks, he estimates that all work will be complete in two weeks.

The faster speeds can make a world of difference for nearby marine companies, which have to delay their work during the repair process.  “It definitely affects our customers,” Dowell said. “We recognize that – and we try to reduce our impact.”

The Ballard Locks, which were built 100 years ago, still remain the busiest in the nation, with 40,000 vessels passing through each year. The Locks also contribute more than $1.2 billion to the Seattle economy each year. 

In addition to facilitating commercial cargo, the Locks have become a tourist destination. More than 1.2 million visitors come each year to watch as ships are lowered between the Puget Sound and Lake Union.

“The Locks turned 100 years old this year,” Dowell said. “What it did for Seattle was huge. Seattle wouldn’t be what it is today without the Locks.” The initial construction, however, had negative affects on salmon. 

Since then, the Army Corps of Engineers has been doing all it can to protect the fish. “We’re working hard to help the salmon,” Dowell said. 

That’s a big reason behind having annual repairs, Katie McGillvray, natural resource specialist for the Seattle District of the U.S. Army Corps of Engineers, explained. 

About 150,000 salmon pass through the Locks annually. A high velocity of water flows through the area. To keep salmon from being scratched and scraped by barnacles on the tunnels in the Locks, the walls are completely scraped clean each year. It’s a massive undertaking, McGillvray said. 

On Nov. 6, crews started pumping all the water out of the chambers – after timing exactly when low low tide occurred, which is the best time to close the gates. 

After the water is almost completely drained, McGillvray brings in a group to rescue fish. “We come out with buckets,” she said. “It’s a huge effort.”

They’re especially focused on saving endangered species. In the past, they have also rescued a seal and a 6-foot green sturgeon. 

Then, the Corps is stationed 65-ft down from the Locks -- in a place where usually only fish and sea anemones see the bottom. They use scaffolding and ropes to rappel to the chambers.  Debris is cleared from the space. One year, workers even rescued a wedding ring from the bottom of the chamber. 

Once the draining and fish rescue is complete, the scraping can begin. Other locks undergo maintenance every five or 10 years, McGillvray said. “We’re the busiest lock in the nation,” she said. “And we’re really unique.”

Because the Ballard Locks join fresh and saltwater together, extra steps are taken to control corrosion of the metal that makes up the structure. 

About 150 “sacrificial anodes” are replaced each year. The zinc bars are mounted on the gates of the Locks – and react with saltwater. They corrode instead of the wall, protecting the infrastructure. 

As part of this year’s maintenance effort, The Army Corps of Engineers is also replacing sill beams, which seal the gates shut. Originally made of wood, they only lasted a couple of years before degrading and becoming habitats for boring clams. Now, the beams are made with a composite material and can last decades, McGillvray said. 

She said crews will also inspect the buoyancy chambers at the Locks – and well as maintain the hydraulics system. “With a 100-year old structure, there’s a lot of work to be done – and a lot of it is below water,” McGillvray said. “Things break when they’re 100-years old.” When the water is drained, parts can be accessed to insure everything is working properly. 

But with the routinely scheduled, comprehensive maintenance program, McGillvray  said the 100-year old Chittenden Locks are expected to keep going strong – and remain safe and operational for marine businesses, boaters and salmon population for years to come.

For more information about the Locks, visit http://www.nws.usace.army.mil/Missions/Civil-Works/Locks-and-Dams/Chittenden-Locks/. Follow the Locks on Facebook at www.facebook.com/chittendenlocks or on Twitter at http://twitter.com/ChittendenLocks.