The Army Corps of Engineers is delaying the use of explosives to blast away treacherous rock pinnacles on the Mississippi River in southern Illinois because crews are having so much success removing the rocks with excavating machinery, officials said Tuesday.

The corps has hired contractors to use explosives to remove the pinnacles that stretch over about six miles near Thebes, Ill. The river's water level is so low in the area between St. Louis and Cairo, Ill., that barge traffic is threatened.

Blasting was scheduled to begin Tuesday but corps spokesman Mike Petersen said excavation barges were removing so much rock that the explosions are on hold for now.

"It's like a backhoe on steroids," Petersen said as he watched the excavation from the shore. "It reaches down and basically scoops rock out of the river. It's just spooning it out right now."

The middle Mississippi River is approaching historic lows due to months of drought, a fact worsened last month when the corps cut the outflow from an upper Missouri River reservoir, further reducing the amount of water flowing into the Mississippi.

Dozens of lawmakers from affected states have urged the corps to restore the flow. They were unsuccessful in that effort but did convince the corps to expedite the rock removal, which was previously scheduled to start in February.

Two excavation barges positioned on each side of a railroad bridge worked constantly Tuesday, backhoe arms digging deep into the river bottom, pummeling rock and pulling up the remains.

"It's a lot safer, a lot cleaner and a lot faster" than using explosives, Petersen said.

The rock removal work is expected to take 30 to 45 days and explosives will likely be needed at some point — officials just don't know when, Petersen said.

When explosions happen, sightseers expecting to view plumes of river water spraying into the air will be disappointed.

"It'll make tiny bubbles," Petersen said. "It's not going to be very exciting to see."

During the excavation work, a constant line of small boats from observing agencies like the U.S. Fish and Wildlife Service and the Missouri Department of Conservation launched at Thebes Landing, an RV and campground at a scenic crook of the river.