Drought and the Mighty Mississippi: USACE efforts to keep cargo flowing
Drought is creating havoc in some sectors of the shipping industry. Persistently low water levels in Gatun Lake have been creating a traffic jam at the Panama Canal reminiscent of the long lines of ships waiting in San Pedro Bay just a few years ago. With the Panama Canal Authority limiting the number of vessels granted passage each day, some companies are paying millions to secure a prime place in line — and two gas tankers recently did a U-turn after traveling all the way across the Pacific.
Closer to home, the Mighty Mississippi is experiencing drought issues of its own. That has grain farmers worried, wheat exports at a 20-year-low, and the U.S. Army Corps of Engineers (USACE) scraping the river’s bottom to ensure barges don’t do the same.
A familiar scenario
Although intermittent drought conditions have been a big problem this year for one of America’s most important inland commercial waterways, unfortunately, the scenario isn’t new. About this time last year, much of the Mississippi River Basin was also at “near-historic lows,” resulting in bottlenecks and increased costs for grain industry stakeholders just as harvest season hit.
Things got so bad at one point that barges got stuck in the muck, and in one traffic jam, more than 2,000 vessels were impacted.
Max Golembo and Julia Jacobo of ABC News describe the fiasco like this: “Last year, hundreds of water vessels, including shipping containers, recreational boaters and even cruise ships, ran aground on the Mississippi in mud and sand that was previously covered. Water levels were so low that hundreds of barges were stuck for weeks as they attempted to transport crops down the river.”
Quoted in a recent Investigate Midwest article, Mike Steenhoek, executive director of the Soy Transportation Coalition said, “Unfortunately, we are watching a movie sequel that none of us want to watch.”
As NASA’s Earth Observatory notes, water levels have been especially low near Memphis, Tennessee. In the images below, comparisons of the Mississippi River near Memphis on September 10, 2021 and around the same time this year demonstrate that the river is “significantly slimmed down in 2023, exposing some of the river bottom.”
Commerce on the Mississippi
According to the U.S. Department of Transportation’s Bureau of Transportation Statistics (BTS), the Mississippi River is the:
Largest drainage basin in the United States
Second-longest river in North America
Fifteenth-largest river by discharge in the world
This BTS schematic map of the Mississippi, its major tributaries, and major ports —as defined by the USACE based on total tonnage—demonstrates how extensive this watershed is.
In addition to being “one of the world’s major river systems in size, habitat diversity and biological productivity,” the Mississippi River is also “one of the world's most important commercial waterways and one of North America's great migration routes for both birds and fishes,” according to the National Park Service (NPS).
In terms of commerce, the NPS says the agricultural products and the “huge” agribusiness industry in the Mississippi River Basin produce:
92% of the nation's agricultural exports
78% of the world's exports in feed grains and soybeans
Most of the livestock and hogs produced nationally
“Sixty percent of all grain exported from the US is shipped on the Mississippi River through the Port of New Orleans and the Port of South Louisiana,” the NPS says, noting that shipping at the lower end of the river focuses on petroleum and petroleum products, iron and steel, grain, rubber, paper, wood, coffee, coal, chemicals, and edible oils.
However, with the Mississippi being so shallow in places, barge companies have been required to reduce the amount of cargo they normally carry and shipping costs have increased significantly.
The role of the U.S. Army Corps of Engineers
Of course, using the Mississippi to move goods requires a reliable channel to keep all those heavy barges afloat — which is where the USACE comes in.
According to the NPS, the USACE maintains a 9-foot shipping channel from Baton Rouge, LA to Minneapolis, MN — while a 45-foot channel is maintained from Baton Rouge past New Orleans to Head of Passes, so ocean-going vessels can access ports between New Orleans and Baton Rouge.
The USACE describes its work along those lines more specifically in a fact sheet about its use of locks and dams — as well as the navigation channel it maintains.
Locks and Dams
“The Corps of Engineers maintains navigation channels, much like road crews maintain highways, as well as builds breakwaters or jetties to protect public property from shoreline erosion,” the USACE explains. “A 9-foot navigation channel is maintained on the Upper Mississippi River so river vessels can transport goods north of St. Louis. To achieve a 9-foot channel in the Upper Mississippi River, Congress authorized the Corps of Engineers to construct a system of navigation locks and dams in the 1930s. Dams are built on rivers to hold back water and form a deeper navigation ‘pool.’”
“Dams make it necessary for river vessels to use a series of locks to ‘step’ up or down the river from one water level to another,” the USACE adds, noting that additional benefits from the locks and dams include:
Adding river recreational areas for public use
Providing water supply for river communities
Serving as nesting grounds for migratory birds
“Sedimentation in the channel is caused by the normal cycle of silt movement, erosion from high water or heavy rains and changes in river currents,” the USACE says. “To maintain the 9-foot navigation channel, the Corps must remove material that settles in the channel area. …Mechanical or hydraulic dredging are methods used for the removal of that material.”
Noting that the removed material is placed in designated areas along the river, the USACE says some of those areas are designated as “beneficial use placement areas.” It describes beneficial use of dredged material as “the productive use of the material by the public or private sectors,” such as “upland habitat development, aquatic habitat enhancement, creation of areas for bird nesting, beach nourishment, winter road maintenance and bank protection and general purpose fill.”
As noted on the Upper Mississippi Waterway Association’s list of monthly USACE reports, the USACE has plenty of ongoing projects in various locations to keep river traffic moving.
Since regularly updated data from the National Weather Service (NWS) indicates that the downward water-level trend is only expected to get worse in coming weeks, the USACE will likely continue its busy schedule as it works to keep all those barges afloat.