For centuries, the Mississippi River and its tributaries have flowed south to the Gulf of Mexico providing residents along its banks a source of transportation, food and recreation.

But when people talk about the nation’s primary river system, they discuss its effect on the nation’s history and the floods that spilled over its banks, putting thousands and millions of acres of homes and farmlands under water. They talk about the era of the flatboats and the steamboats that plied the river shipping goods north and south for consumers of factories.

They don’t discuss why the nation’s first and largest super highway remains underutilized by companies moving goods from a northern factory south.

According to statistics by the American Waterways Operators and the Waterways Council, 4 percent — about 604 million tons — of the total cargo moved inland during 2014, the most recent year for statistics, was moved by barge along the nation’s inland waterways.

“One of the key things about the water is its capacity,” said Debra Calhoun, senior vice president for the Waterways Council Inc. a coalition of towboat operators, conservation groups and industries served by waterways companies. “A 15-barge tow is equal to 1,050 tractor trailer trucks, 216 rail cars and six locomotives.”

“If we take away the capacity of the water base, you wouldn’t be able, none of us, in any part of the country, be able to drive anywhere because of gridlock,” Austin Golding, executive vice president of Golding Barge Line, added. “We produce the least amount of emissions. It’s the safest. It’s the most fuel efficient (transportation system). We can go 615 ton miles compared to 413 by rail and 155 by truck. It’s the silent workhorse of the transportation supply chain.”

And for Mississippi, it’s one of the most lucrative.

Commodities such as oil, manufactured goods and chemicals, shipped to and from Mississippi ports totaled about $46.3 billion in 2014, providing a direct impact to the state of $2.4 billion. Mississippi ports and waterways companies employ 14,435 people.

“We’re buying groceries from people in Mississippi. We’re calling diesel mechanics from people in Mississippi, we’re buying uniforms from people in Mississippi,” Golding said. “The support it takes to have those people on the water would be impacted probably four-fold. These guys, once they become a captain, end up making $130-$150,000 a year. They’re covering house notes, car notes, and college tuition. And that’s with a high school diploma.”

The impact of waterways transportation, he said, influenced Hinds Community College to open a barge transportation program, adding 250 people went through the program in 2015, “and there’s 100 percent placement.”

Mississippi, he said, has a unique employment base.

“There’s not a lot of industry and we have a lot of people who like to work hard, and don’t mind working outside, and maybe college was not an option for them,” he said. “You cannot go to an urban space and capture that type of an employee. You might capture that same attitude, but you can’t capture that guy who grew up on a farm working on tractors or the guy who has grown up with a mechanical sense.”

The waterways industry, he said, attracts people from a rural setting who like the industrial application of their skills.

“So Mississippi, is a very fertile recruiting base,” Golding said, adding companies from across the country have hiring offices along the river from Mississippi to St. Louis.

Part of the reason for the Mississippi’s draw is its multiple uses for work and recreation. It’s a characteristic Calhoun said waterways operators want to protect.

“People don’t play on the highway. They don’t look at it as an accent to their property,” Golding said. “It’s the same thing with airports, same thing with railroads. We literally rely on the environment for all working space.

“We actually work within the environment. So when you invest in waterways, you’re not paving paradise to put up a parking lot; you’re helping make paradise something that’s sustainable and there’s more benefit to it than industry, and that’s what taxpayers have to think about.

“I am not just throwing money at a pothole. I’m throwing money at a cause that also has an economic impact on my daily life, and we don’t just tell the politicians that or the purse holders that. We tell the guys on the boat that.

“We maintain that mentality ourselves when we operate, we’ve got to be good stewards of our work environment, so that’s why we ask people to help maintain it. We work to promote our stewardship; help promote this as an environmental cause because this is an investment in the environment more than it is an investment in industry.”

And the waterways system has something rail and the trucking industry is slowly losing, Calhoun said, capacity. The full capacity of the Mississippi and tributaries with their lock and dam systems hasn’t been threatened. “There is capacity to move this stuff,” she said.

“We have not maxed out our capacity,” Golding said. “There may be some ports that will tell you they’re maxed out, but that’s a local issue, but from New Orleans to St. Louis it does not look like I-55 at rush hour in Jackson. It looks like Clay Street at three in the morning. There’s a lot room to grow out there.”

One way of helping increase that capacity, Calhoun said, is ensuring the line of goods traversing the waterways is not interrupted. And that means ensuring the systems of locks and dams along the upper Mississippi region are maintained or are improved to handle increased tows and barge traffic.

“If a lock and dam goes down on the Industrial Waterway in New Orleans and is shut down, the detour affects the Chevron refinery in Pascagoula, Chiquita Banana in Gulfport; anything from Mississippi to the western part of U.S., Anderson Tully can’t get wood products; it might affect Cam 2 or Magnolia or Ergon’s oil supply,” Golding said.

When a barge hit the Interstate 20 bridge in January, shutting down the river, he added, “It didn’t take 48 hours for 100 boats to get stacked up north of Vicksburg. That’s several 100 tons of product, and they’re waiting in Vicksburg. So the Port of Vicksburg suffered, the Port of Natchez suffered; I bet the port of Corpus Christi (Texas) suffered. I bet the ripple effect of the shutdown was massive.”

The same thing could happen with a lock failure on the upper Mississippi.

Calhoun said the Waterways Council is working with the Army Corps of Engineers on programs to improve systems, and lobbies Congress to make sure the funding is available to the Corps to do the work.

She said the 2014 Water Resources Development Act has laid out the policy and set priorities for work on lock systems on the upper Mississippi.

She said projects are underway to expand capacity on the upper Mississippi to accommodate large tows. “We need to be ready as a nation modernize,” she said.

One advantage the waterways operators have, Golding said, is representatives and senators from Mississippi and other waterways states. Mississippi, he said, has taken the lead “and our local constituents have voted in people who understand it (waterways); they get it.”

“The waters are an economic generator for cities and states and regions and for the nation,” Calhoun said. “This is critical infrastructure; it allows the system to be navigable, because of various depths, as our forefathers saw it.”