Thinking Deeper

Mighty Mississippi gets man-made help
Oil Tankers On The Mississippi
A line of oil tankers transporting fuel to the refineries located along the Mississippi River just north of New Orleans, Louisiana.

While enjoying the view of bustling commerce on the Mississippi River from various vantage points in New Orleans, it’s easy to conclude that the city has been merely fortunate: Mother Nature put the river there, and for 300 years New Orleans has benefited from the exceptional access to inland and overseas trading routes that the river provides. But to believe that New Orleans simply lucked out with a good location is to oversimplify man’s relationship with one of the great rivers of the world.

The fact is, the biggest cargo ships, barges and passenger vessels that ply the lower Mississippi River are able to use the waterway only because of huge investments of time and money that go into maintaining the river in a navigable state. New Orleans recently received a reminder of this when the federal government committed $85 million for dredging the river’s channel. 

Since the early 1800s, the U.S. Army Corps of Engineers has routinely dredged the main channel of the Mississippi River to clear out layers of silt that continually accumulate on the river bottom. The dredging ensures that deep-draft vessels that traverse the river between its mouth and Baton Rouge will always have access to Louisiana’s major ports.  

The Corps keeps the channel clear by using a dredge boat that can pump as much as 1,300 cubic yards of silt per hour. Between dredgings, the Corps deploys a fleet of survey vessels that use global positioning and echo sounders to measure the river’s depth. These surveys enable river pilots to guide ships up and downstream, but their primary purpose is to determine when, where and how much dredging is needed.

For many years, the goal of the dredging has been to maintain a depth of 45 feet in the river’s main channel. But this year the Corps plans to deepen the channel to 50 feet from Baton Rouge through New Orleans. The deeper channel is necessary to accommodate the large ships known as “New Panamax” vessels, which the Panama Canal was widened to accommodate during the past decade, as well as even larger “Post Panamax” vessels that, among other hurdles, must fit beneath the Crescent City Connection bridge in New Orleans on their way up or down the river. In all, 256 miles of the river will be deepened. 

The Corps in 2018 told Congress that the project would benefit the nation’s economy to the tune of $127 million a year. In announcing the Corps’ spending plan, Congressman and Majority Whip Steve Scalise (R-La.) pointed to its strategic importance. “The Mississippi River Basin has an unprecedented impact on our national economy, global competitiveness and American job creation,” he said. “Modernizing our infrastructure and deepening the river to 50 feet will help strengthen Louisiana’s dominance in domestic and international commerce.”

The project will entail significant additional construction costs related to relocating utility lines that run beneath the river and transporting dredged sediment for use in building up coastal wetlands. Ongoing maintenance of the river from Baton Rouge to the Gulf of Mexico will cost a projected $250 million annually. The state must shoulder more than $100 million of the price tag.

Brandy Christian, president of the New Orleans port, predicted big benefits across a wide region. “With two integrated container terminals served by one of the strongest rail, barge and road gateways, along with unrestricted air draft and 50-foot water depth, Port NOLA will be able to meet the growth demands for the entire Lower Mississippi River for the next century,” she said. 

A study of the project’s national impact suggests it will create 17,000 jobs and generate $850 million in increased income for American workers.