(CBS News) GRANITE CITY, Ill. - A powerful storm system known as a derecho swept across the Midwest Tuesday, knocking out power to more than 300,000 homes and businesses in Illinois. But it did little to reverse the damage done by the record drought across much of the country -- now taking a toll on one of America's most important commercial waterways.
Barge operator Mark Fletcher has been shipping corn and grain on the Mississippi river for over 30 years. Twice a day, he checks river levels in St. Louis. Today, it's nearly 12 feet below average, making the river narrow and shallow.
"It takes more turns, more shipments to get the same amount of tonnage down to New Orleans," Fletcher said.
The drought has exposed sandbars. To navigate around them, tugboats must push fewer barges that carry less cargo. Fletcher is losing $3,600 per barge.
Consumers may start to be affected. "The company that buys the corn or wheat or the soybeans to process and other food items is obviously going to raise their prices over time," Fletcher said.
One barge can haul as much as 58 tractor trailers at a fraction of the price. But with water levels so low, navigation -- a tough skill to begin with -- becomes even more dangerous for riverboat pilots."
"The biggest fear right now is as water level drops, they're going to continue to run aground," creating an aquatic traffic jam, Fletcher said.
One of Fletcher's barges has already run aground and will be stuck for months. The Army Corps of Engineers plans to dredge the river to keep it open. But that's little comfort to port operator Dennis Wilmsmeyer.
"If the river gets silted in to a point that's not passable, you'll see delays of barge tows for two to three days while they're in there dredging that area to get it back open again," he said. "We know that as the river continues to drop, the problem just worsens for everyone."
Many fear this drought could be as bad as 1988, when the river was so low it was closed to barge traffic.
"We can't do anything about it," Fletcher said. "Mother Nature is going to do what it's going to do."
As many as 70 of Fletcher's barges are tied up at the dock. Water levels are expected to keep falling along the Mississippi until at least September.