Some heavy equipment is pounding away this week at the rock in a section of the Mississippi River south of St. Louis. The U.S. Army Corps of Engineers says the removal is essential to keeping cargo moving along the river. Crews are working this week at Thebes, Illinois, near Cape Girardeau.

Shipping on the Mississippi is vital to the U.S. economy. A Corps spokesman said more than 100 million tons of cargo, including 60 percent of the nation's agricultural exports, move along the river every year. And the engineers have a responsibility to keep the shipping channel at least 9-feet deep and 300-feet wide.

"But in these areas, the river actually has a bend," said Mike Feldman, project management chief of the Corps of Engineers St. Louis District. "These pilots don't have the precision in a bend that they would have in a straight stretch of the river, so we try to provide some additional width in those bends."

The work, which will continue as long as the water levels are low enough to get heavy equipment out on the river, will not shut down traffic on the Mississippi. The Corps has been working with shipping companies and the U.S. Coast Guard to find ways to keep cargo moving, while the rock is being removed during the day.

The effort dates to the 1980s, when most of a large natural formation in the area was taken out. Crews are now working on the leftovers; conditions have been less than ideal since 2014. That's mainly because the water level has to be low enough to bring out big machinery, including a major piece of hydraulic equipment.

"Which is basically a large jackhammer attached to an excavator," Feldman said. And it's needed to get rid of the largest pieces, which are broken down and moved out of the way.

Credit File photo | St. Louis Public Radio The U.S. Army Corps of Engineers is responsible for making sure there is enough room for cargo shipments to make it through the bends along the Mississippi River.

But where does it all go?

"We basically take it from the area that we find it and drag it into areas that are deeper," said Feldman

The rock can be moved anywhere from a few hundred feet from its original location to a few hundred yards in a deep hold.

"We don't physically remove any of the rock from the river."

