The Mississippi River drought was big news when barges got stranded, receding waters revealed historic artifacts, and river traffic briefly ground to a standstill in October.
But the drought didn’t end when the channel reopened.
Barges have been able to transport goods down the historically shallow Mississippi only because the US Army Corps of Engineers has been constantly vacuuming the bottom of the river.
“There was a few months of pretty intense management,” Lou Dell’Orco, the chief of operations and readiness at the Corps’ St. Louis District, told Insider.
The Corps maintains a 9-foot-deep channel down the Mississippi River so that ships and barges can travel freely.
To keep that channel open, Dell’Orco had to bring in dredges from other districts.
At some points, three vessels were operating 24/7, traveling to chokepoints in the St. Louis area, dropping their suction tubes to the riverbed, inhaling material from it, and transporting the material through tubes to designated disposal sites — like “a giant vacuum cleaner,” Dell’Orco said.
“Our dredge can fill up an Olympic-sized pool about every hour,” he said.
It’s normal for the Corps to keep one dredge at work 24/7 throughout the season — but not two or three, Dell’Orco said.
A four-day break during a cold snap around Christmas gave crews time to do minor maintenance on the vessels. One of the dredges left the district about that time, and the second one left St. Louis last week, Dell’Orco said.
More rain and snow have improved conditions on the river, and it looks like the end of the crisis is on the horizon.
“Commerce is moving with no restrictions relative to drought,” Deb Calhoun, a senior vice president at the Waterways Council, a group that advocates for modern waterway infrastructure, told Insider in an email. “We will be watching for high water next, which is something that normally happens around this time of year.”
Dell’Orco expects his teams can stop dredging by the end of January.Drought damage control by the numbers: 3 dredges sucking up the river bottom 24/7
Since July, the St. Louis District has dredged about 9 million cubic yards of material from the bottom of the river in about 70 locations, Dell’Orco said. In a normal year, they would dredge only 3 million to 4 million cubic yards.
That’s more than 2,700 Olympic-size swimming pools of material removed from the riverbed this year, compared with just 1,000 Olympic-size swimming pools in a normal season.
This year, the dredging season has stretched at least 100 days longer than normal, Dell’Orco added.
He estimated that it cost about $6.5 million to operate two dredges for a month. Throw in a third, and he said the Corps was looking at $10 million a month.
Climate change could make droughts like this year’s more common
The last time the Mississippi dropped to such extreme lows and required this much management was in 2012.
No research has directly linked these drought events to the climate crisis, but scientists are confident that rising temperatures will amplify droughts across much of the US.
In this case, a summer of record heat waves baked away some of the river’s water, and then a flash drought struck the Ohio and Missouri river valleys, robbing the Mississippi of the snowpack that usually feeds it.
It’s unclear how climate change will affect the Mississippi River in the long term, Paul Pastelok, an AccuWeather meteorologist, previously told Insider. But it’s possible that the river’s drought cycle accelerates.
Instead of every 10 to 15 years, for example, drought could strike the river every five to 10 years.
Forecast maps show the Mississippi’s drought may end soon
Much of the Mississippi River basin is still classified as in a drought, including the lower regions that help farmers transport grain for export, according to the US Drought Monitor.
That could end in the next few weeks, though. Forecasts from the National Weather Service’s Climate Prediction Center offer hope that drought will dissipate in February across much of the Mississippi River basin.
Above-average precipitation across the northern Midwest could help replenish the river throughout the month. That’s when Calhoun and Dell’Orco will be on the lookout for flooding.
After that, forecasts show there could be no drought conditions across the Mississippi River basin for the first time in months.
That would give Dell’Orco’s team time to do maintenance on their vessel before the dredging season begins again in July.
“It’s really a shorter maintenance season. You’ve got March through the middle of June to to get it ready to go,” Dell’Orco said.
That shouldn’t be a problem, he added. But still, he said, “it’s a 90-year-old vessel — it needs a lot of TLC.”
source: businessinsider