Ida caused Mississippi River to temporarily flow backwards as hurricane hit Louisiana

Tropical Weather Atlantic
Posted at 11:01 AM, Aug 30, 2021

NEW ORLEANS, La. — When Hurricane Ida hit Louisiana as a Category 4 storm on Sunday, it temporarily reversed the flow of the Mississippi River.

Ricky Boyette, a spokesman for the U.S. Army Corps of Engineers, told The Associated Press and USA Today that engineers detected a “negative flow” on the river as a result of the storm surge from Ida.

USGS data shows that the river discharged about 300,000 cubic feet per second in the days leading up to the hurricane and as the storm hit on Sunday, it discharged nearly 40,000 cubic feet per second in the opposite direction. That reversal occurred just over a couple of hours.

Scott Perrien, a supervising hydrologist with the USGS Lower Mississippi Gulf Water Science Center in Baton Rouge, told CNN that the river level rose to about 7 feet on Sunday as a result of storm surge pushing up the river at the USGS gauge located in Belle Chasse.

During that time, Perrien said the flow of the river slowed from about 2 feet per second down to nearly half a foot per second in the other direction.

However, Perrien added that it is possible deeper portions of the river did not reverse flow directions, since the gauge does not measure the flow of the entire waterway.

Now that the storm has moved northward, the river has risen and it’s discharging more water into the Gulf of Mexico than the days leading up to the storm.

In the wake of the storm, most of the southeastern region of Louisiana is without power and residents are assessing the damage from Ida. Search and rescue efforts are also underway.

At least one person had died as a result of the storm as of Monday morning. Officials believe there will be more.

“I am certain that as the day goes on, we will have more deaths,” Gov. John Bel Edwards told “The Today Show” on Monday. “We’re going to be getting information throughout the day. I fully expect that the confirmed death total (will) go up considerably.”