THEBES — Contractors from Iowa and Ohio are using explosives and excavating machinery to remove bedrock pinnacles from a 6-mile stretch of the Mississippi River between St. Louis, Mo., and Cairo, as part of a $10 million project funded by the U.S. Army Corps of Engineers.

The months of drought have dipped water levels on the Mississippi River to record lows. It has exposed the rocks underneath, causing a tricky situation for boats and barges. Barge industry trade groups have expressed concern that the ever-dropping river could further restrict barge weights to the point that shipping on the river is halted.

“Think about it like we’re driving down the highway in your car,” said U.S. Coast Guard Captain Byron Black. “If the highway was to suddenly get narrower, it becomes more of a challenge to safely operate.”

To ensure the Mississippi River remains open to barge traffic, the U.S. Army Corps of Engineers has hired contractors to remove bedrock from the river. The contractors are drilling holes in the bedrock pinnacles — described as six times harder than concrete — and then blowing them up with explosives. The contractors are also using excavating machinery to remove the bedrock.  

“We’re using excavators because the river is so low and it’s giving us access with heavy equipment to tear the rock right out of the bottom of the river,” said U.S. Army Corps of Engineers Spokesman Mike Peterson. “So we’re having a lot of success with that and that’s reduced the need for blasting.”

The U.S. Army Corps of Engineers hope to increase the depth of the 6-mile stretch of the Mississippi River by six inches, while removing enough bedrock pinnacles to fill 50 dump trucks.

“We have to work with maintaining the channel for as long as possible, with not just a short-term view, but also the long-term view,” said Sue Caffeau, a public affairs specialist for the St. Louis District of the U.S. Army Corp of Engineers. “Decisions are made based on the idea that droughts are not usually just one season, so we’re kind of preparing, as we always do for the water management, to be as long-term as possible.”

Crews began removing bedrock pinnacles near Thebes on Dec. 18. 

According to Petersen, the project will be completed by the end of March.

The six-mile stretch of the Mississippi River has been shut down between 6 a.m. and 10 p.m. to let crews work on the bedrock. For eight hours overnight, barge traffic is being allowed to pass in one direction at a time. The U.S. Coast Guard is watching over the barge navigation and setting up a system for barges wanting to pass. 

“For everyone’s safety, there have been hours that barges are asked to queue up until 10 p.m. and then they float through until 6 a.m.,” said Caffeau. “The queue doesn’t get very long and it’s never a last-to-the-second session. Everybody has been able to get through.”

The last time the U.S. Army Corps of Engineers funded a project for the removal of bedrock from the Mississippi River was 1989, following one of the worst droughts in the history of North America.