The Mississippi River hovered just a few inches below the low-water mark in Memphis Wednesday afternoon — a notable improvement after months of record drought, but still unusually low for this time of year.
Lack of rain brought drought to much of the Mississippi River basin early this summer, and it’s likely going to linger into winter, U.S. Army Corps of Engineers leadership said during a press conference on Nov. 8 in Memphis, while a dredge was working nonstop to keep the river channel open a few miles south.
It’s the second year in a row that extreme drought has caused a shrinking channel, forcing the Corps to dredge later in the season than normal. Last year, low river levels lingered into the winter, and dredging continued until January.
It’s shaping up to be the same this year.
“We’re anticipating challenges as we progress into the winter months,” said Colonel Brian Sawser, commander of the Corps’ Memphis District.
A persistent drought this summer left the dry ground thirsty, so it absorbed much of the water that would have eventually reached creeks or streams on its journey to the Mississippi, said Mike Welvaert, a hydrologist at the North Central River Forecast Center.
“We’re so far behind normal that we just can’t catch up,” Welvaert said.
Future outlook
The region is in an El Niño, a climate shift in the Pacific with wide-ranging weather implications. It tends to bring warmer and drier conditions across much of the Midwest, said Illinois State Climatologist Trent Ford. Farther south, though, these periods are usually wetter than normal.
An El Niño is characterized by unpredictable and extreme weather patterns, said Sarah Girdner, acting hydraulics and hydrology chief of the Corps’ Memphis District, and this climate pattern is expected to continue through next summer.
Along the lower Mississippi River, forecasters are expecting above-average rainfall, but the upper river is more of a toss-up, and it supplies 90% of the water that flows past Memphis.
It’s still possible to recover from the dry conditions this year, but only if the upper river basin gets a lot of moisture, Ford added.
“What we really need is a cold, wet and snowy winter to help recharge this river,” Ford said.
Rain in parts of Minnesota this fall helped replenish soil moisture, lakes and other smaller bodies of water, but not much of it reached the river.
And time is running out. When temperatures drop and things start freezing, the flow from up north will shut off.
There’s another drop in river flow that’s tied to the end of the navigation season on the Missouri River, when dams along the river begin storing water again, said Andy Schimpf, operations manager for the Corps’ St. Louis District Mississippi River Project.
These factors are expected to keep river levels low through winter.
“All of that to say: we don't really know,” Girdner said. “But it doesn't look great right now. It’s going to take a long time for the river to recover.”
In the meantime, industry on the river will continue to grapple with drought.
Costly dredging to keep a low river open
The Corps must maintain a shipping channel that’s at least nine feet deep. For the most part, when it’s shallower than that, barge companies have to load less cargo on each barge to ensure safe travel — which is costly and cumbersome.
Corps officials say dredging is a key temporary measure to maintain a navigable channel. In an average year, Donny Davidson, chief civilian deputy for the Memphis District, said the district spends about $4 million for about a month of dredging. Last year, that cost doubled and went on for about three months.
They started dredging earlier this year. Since June, the Corps has spent $38 million maintaining the channel, mostly through dredging. They’ve moved the equivalent of 5,000 Olympic-sized pools of sediment since June, and the effort could last up to six months this year, Davidson said.
“I think we are collectively getting better at getting ahead of this and knowing what the signs are,” Davidson said.
This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouri in partnership with Report for America, with major funding from the Walton Family Foundation.