WEBBERS FALLS, Oklahoma - About $4 billion worth of commerce travels through Tulsa each year on the Arkansas River; but right now, barge traffic is shut down.

Lock and Dam number 16 near Webbers Falls is normally full of water, but right now it’s empty; it’s only temporary and for a good reason.

The lock is part of the waterway that ships in about $300 million to Oklahoma's economy each year.

“Grain, agriculture, finished product, steel, coal,” those are just some goods shipped, according to Tulsa District Corp of Engineers COO, Earl Groves.

Lock and Dam number 16 is just one of 18 along the Arkansas River navigation system. Right now, it’s closed while the Army Corps of Engineers makes major repairs to the 50-year-old gates.

“Below the water line, that's where all the heavy lifting's going on,” Groves said. “The gates are in such poor shape, just from wear and tear and water.”

Water rust and corrosion are issues that must be addressed.

“If the structural members are rusted so bad and the delaminated steel is that bad and we haven't fixed it, it could, theoretically, crush like a coke can in your hand. We don't ever want that to happen,” Groves said.

He said if the gates were to fail it would shut down the whole system, costing the state $2 to $3 million per day - which is why making sure the two gates are as good as new again is so important.

Groves said, “There's things that come out of the seven-state area that are shipped worldwide right down this system. We don't ever want a failure to happen.”

The Corps said it picked a slower cargo season to shut down the lock. The 21-day project is more than halfway through.