He said the Corps expects to eliminate current restrictions on when barge shipping may take place by the end of January, when its work to remove rock outcroppings that can ground vessels in low water is complete.
Petersen said efforts by the Corps to keep the river accessible during drought were likely to be necessary at least through 2013, because the region was likely to remain in drought for at least another year.
“While a flood comes up and down relatively quickly, a drought sticks around usually for a couple of years,” he contended. “Droughts almost never last only one year.”
He said the 200-mile region just south of where the Missouri and Ohio rivers intersect with the Mississippi would need “tremendous snow packs and heavy spring rains” to eliminate current drought conditions and low water on the river.
In the absence of any big changes in the weather, the Army Corps of Engineers was working on making the middle Mississippi a “more efficient channel” with a smoother, well-dredged bottom, an acceptable depth of 9 feet and a normal width of 300 feet, he said.
Petersen said the river would, in all likelihood, be able to remain open even if the drought lingered, although he said there was no way to know absolutely. In the late 1980s, when the Midwest suffered a serious drought but not one as severe as the current one, the Mississippi River was temporarily unable to support barge traffic.
“Closure is not unheard of,” Petersen said, although he added that technological and engineering resources had advanced in the last 25 years.
“We’re giving better measures of surety to those looking 30 days out” and making plans to ship on the middle Mississippi, Petersen said.
The current work planning rock outcroppings builds on a much bigger effort undertaken in the late 1980s when the region was also in drought, Petersen said. At that time, 200,000 cubic yards of rock called pinnacles were reduced significantly; the current effort only involves 890 cubic yards, Petersen said.