Drought conditions on the upper Mississippi River have reduced water levels to such an extent that barges are hitting sandbars, stalling river traffic and costing the shipping industry hundreds of thousands of dollars, according to experts.

Since the beginning of July, nine barges have run aground, affecting 200 to 250 barges, said Bob Anderson, a spokesman for the Army Corps of Engineers Mississippi Valley Division. The two most recent river closures, in Greenville, Miss., were caused by excess sediment deposits.

Low water levels and barge groundings have shut down the river for two full days this summer, Anderson said. The result is a hit to shipping companies up and down the route. Corporations automatically lose about $10,000 in revenue as towboats sit idle in the river, Marty Hettel, senior manager for bulk sales at AEP River Operations, said in an email. Losses from stationary barges and late shipments are more difficult to calculate but could be significant.

These blockages only add to the host of drought-related setbacks facing the industry. Heavy barges must lighten cargo loads to cope with low water levels. Lower water levels also reduce the area of the river open to traffic, meaning fewer barges can safely travel to ports. Unlike trucks or trains that can reroute to avoid traffic jams and track issues, barges can only run north or south -- there's no getting around affected areas.

"Our members are still reducing the size of their draft and limiting the number of tows," said Ann McCulloch, spokeswoman for American Waterways Operators, a national trade association.

Every 1-inch loss of water decreases the carrying capacity of a barge by 17 tons of cargo, according to a news release by American Waterways Operators. A normal tow has 15 barges, so a 1-foot loss of draft will reduce capacity by about 3,000 tons. Depending on the commodity a barge is carrying, deficits could be considerable.

"Each foot of draft could mean anywhere from $600,000 to $1 million in loss to a vessel because you're light-loading a vessel, leaving some cargo on the dock," said Matt Gresham, a spokesman for the Port of New Orleans.

Economic and political downsides

Major waterways haven't seen these kinds of losses since 1988, when the United States last experienced such a severe drought. That year, the river was closed for three days when barges ran aground, contributing to an estimated $1 billion in damage to the shipping industry, Anderson said.

Last year's weather is partially to blame for this year's obstructions. In 2011, large portions of the Mississippi River flooded. The high waters deposited more sediment on the riverbed than usual. Thus, the drought has exacerbated the already existing problem -- less water and more sediment is a menacing combination for shippers.

In response, the U.S. Army Corps of Engineers has a team of employees working around the clock. Five dredgers run along the river, removing sediment before it grounds barges. Survey boats, the corps' eyes on the river, scout for problem areas, placing buoys to warn pilots of potentially dangerous stretches.

The constant dredging and surveying cost money. Though it's not uncommon for the corps to mobilize, this year's dredging projects are more intense than usual, Anderson said.

The upper Mississippi, where the drought damage is the most extensive, has a $21 million budget. So far, the corps has obligated $17 million of that for shallow-water dredging, Anderson added. Yet it might not be enough.

"In those districts where they have the drought ... they need additional funding. Without earmarks in Congress, they have to find a way to get supplemental funding," said Sean Duffy, executive director of the Big River Coalition. "They clearly have a need for supplemental funding."

Anderson said he's not worried about funding. The real problem, in his opinion, is the lack of rain. If conditions on the river don't improve, this could be an issue for President Obama's 2010 National Export Initiative, which aims to double U.S. exports by 2014. U.S. rivers transport more than 60 percent of the nation's grain exports and 22 percent of domestic petroleum and petroleum products, according to a report by the National Waterways Foundation.

The low river levels could also increase the cost of some goods, Hettel said. With the economy on every politician's mind, a spike in commodity prices could factor into this year's election agenda, he added.