WBIR.COM - It's maintenance that comes around once every decade for the lock at Fort Loudoun Dam in Loudon County.

While the work being done is routine, the views in the meantime are anything but normal for East Tennessee. 

This week, the Tennessee Valley Authority and United States Army Corps of Engineers have the lock drained, with workers at the bottom of the 360-foot long basin.

It's like a football field sized bath-tub, temporarily empty.

"When people first see it, they think 'Oh man, this is really big.' That's usually what you get," Keith Holley, the Project Manager for the US Army Corps of Engineers, said.

In order to get two shifts of 20-25 workers going around the clock at the bottom of Ft. Loudoun's lock, they first had to pump out nearly 40 million gallons of water.

"These are some of our biggest projects.  They're very fast. We have short periods of time to do them, so we have to work around the clock," Jonah Beckler, Project Manager for the Tennessee Valley Authority, said.

They'll be sandblasting, painting gates, working on valves, and repairing other things like a bumper they believe a barge rammed.

"That's actually what the barges rub up against on the gates, so it's pretty common," Beckler said.

The work itself only comes around once a decade and costs about $2 million.  With it, they're hoping to continue to provide reliable transportation all kinds of materials up and down the Tennessee River.

Melton Hill and Watts Bar Dam are also on this list of maintenance projects this summer.

"You're holding back the river, the Tennessee River, so everything has to be big," Holley said.  "You've got to go through this lock right here to go between Knoxville and Paducah."

A lot of materials use the river. Road salt is one in particular. TVA said most of the salt that comes to East Tennessee makes its way here via the river system.

"We should be completely done on May 5 and starting to work our way out of here," Beckler said.

As they move out, water will once again move in, allowing that river traffic to flow just like normal for another decade, if all goes well.