Corps, Partners Prepare For Low Water On Lower Miss

While threatening assets in southern Louisiana, Hurricane Francine could provide a brief respite for low-water conditions on the Lower Mississippi River.

The Memphis Engineer District held a news conference September 11 to inform local media outlets about low-water conditions on the river for the third year in a row.

Col. Brian Sawser, commander of the Memphis Engineer District, said the Memphis gauge was at nearly –8 feet on September 11, about 4 feet higher than when it set the all-time low record in October 2023.

He stressed lessons learned during similar conditions in the past two years, including the importance of close collaboration with the Corps’ partners.

“I think that has made us more responsive to some of the challenges, primarily to navigation on the Mississippi River,” he said.

Partners include both industry groups and the Coast Guard, with survey boats that evaluate water depth and buoy tenders that move buoys that mark the navigable channel working in concert with Corps-owned and Corps-contracted dredges. So far, Sawser said, industry has not seen the closures and groundings due to low water that have marked some previous low-water years.

Michael Clay, chief of hydraulics and hydrology for the district, said the river has been dropping an average of about 6 inches every couple of days, but that rain from Hurricane Francine could “flatline” the gauge for about a week before it looks like it will begin falling again.

“We haven’t bottomed out, but we’re still well below the average stages you would expect to see in the month of October,” Clay said.

Most gauges along the Lower Mississippi are reading 2 to 4 feet above the lowest stages from last year, he said.

The Corps has been working closely to coordinate releases from upstream reservoirs at Olmsted Locks and Dam on the Ohio, Kentucky Dam on the Tennessee and Barkley Dam on the Cumberland River, but those reservoir levels are close to their minimum pool for this time of year, he said.

The Nashville Engineer District sent out a news release September 11 about the expected effect of the remnants of Hurricane Francine, which it said would be moving through the Cumberland River Basin September 12-15. The area is expected to receive 1 to 4 inches of rainfall with isolated areas potentially receiving 5 or more inches.

The heaviest rainfall was expected in western portions of the Cumberland Basin, particularly within the J. Percy Priest, Cheatham and Barkley watersheds.

“All of our flood risk management projects are currently functioning as intended,” said Lt. Col. Robert Green, Nashville District commander. “If you are planning on being on or near the water over the next few days, we urge the public to use caution and be prepared for sudden water condition changes and direct any immediate emergency needs to local emergency services.”

Except for the tropical system associated with Hurricane Francine, the region has trended drier for the time of year in 2024 compared to 2023, Clay said. Additionally, he said, while a major component of last year’s low-water conditions was drought in the middle Mississippi Valley, this year the region fared better. However, the Ohio Valley was drier than usual in June and July and extremely dry for August, and the Ohio makes up much of the volume of the Mississippi below their confluence at Cairo, Ill., where the Lower Mississippi begins.

Matt Young, chief of the navigation branch, said that areas of concern were just below the confluence with the Ohio, where the dredge Potter was at work, along with near the Interstate 40 bridge in Memphis, where the dredge Jadwin was working.

The Coast Guard sent out notices September 11 of channel reductions to 550 feet at Lower Mississippi Mile 920.8 and to 530 feet at Mile 925.1, advising mariners to implement one-way traffic at each point. Additionally, the Coast Guard received a report of shoaling between miles 518 and 519 along the left descending bank and urged caution in that area.

Other Coast Guard notices indicated that the dredge Potter would be at work near Mile 1.3 on the Upper Mississippi River and the dredge Angela Kay at Upper Mississippi River Mile 703.2.

Memphis Engineer District senior project manager Zach Cook noted that last year’s dredging removed the equivalent of 7,800 Olympic-sized swimming pools of sediment from the river to help keep vessel traffic moving. About 700 million tons of cargo is moved annually on the Lower Mississippi River, he said, with an economic benefit to the nation of nearly $200 million.

The Memphis Engineer District includes 350 river miles along six states bordering the Mississippi River, and the district is also responsible for 10 federally maintained harbors.