That continues to be important, since there’s widespread understanding that the Corps and river users could face new challenges from drought this year.

“Very few droughts are one-year events,” Petersen acknowledges. “The 1988-1989 drought cycle wasn’t fully broken until 1993. As we’ve seen in the last two years, the Mississippi can change its mind very fast.

“We’re still living from [rain] forecast to forecast.”

Iowa State Extension Climatologist Elwynn Taylor explains the dynamics behind Petersen’s example. “When precipitation returns, soils will wick it up until they reach full field capacity. In much of the Corn Belt, that means 10 in. water in the top 5 ft. of soil before the tiles start running.

“In 2012, we had crop roots going deeper, down as much as 8 ft., and they took all the available moisture. To replenish that would require 16 in. of rain – then the agricultural drought will be over and any excess precipitation will percolate into wells, tiles, streams and rivers to ease the hydrological drought.”

Though rains have returned in much of the eastern Corn Belt, Taylor expects to see “precious little correction” of the hydrological drought in 2013.

“That’s going to mean more limits on the headwaters of our great rivers. I anticipate shipping will still be limited above the confluence of the Missouri and Mississippi in the fall of 2013, and probably above the confluence with the Ohio.”

The Soy Transportation Coalition’s Steenhoek is also concerned.

“It’s a big deal with water levels already depleted. We would hate to start the year already low seeing barges loaded light.

“We don’t manufacture a unique product like iPads where you have the luxury of passing additional transportation costs along to your consumer. Our primary competitive advantage is our ability to out-deliver other suppliers," he says. “Our farmers pay the freight.”

The AWO’s McCulloch raises another concern: “If we get into a prolonged drought, the question is whether you continue to manage situation by situation or do you take a more comprehensive look at the Mississippi and all its tributaries. That’s the next question for the Corps and the river users to address.”

Corps officials are anticipating they could have less water to work with than they had in 2012.

“Drought still affects the entire Midwest,” says Petersen. “The Missouri River is dealing with the same drought as the Mississippi. Water management is difficult in good years, but in a drought, it is very contentious.”