New Orleans freshwater supply threatened by salt water creeping into Mississippi River
The saltwater intrusion is expected to occur within a few weeks. In the meantime, the U.S. Army Corps of Engineers is building an additional 25 feet to an underwater barrier known as a “sill" in the Mississippi River.
New Orleans freshwater supply threatened by salt water creeping into Mississippi River
Drought has caused the flow of the Mississippi River to run low, compromising its ability to hold the salt water of the Gulf of Mexico at bay. Sept. 27, 2023.
NEW ORLEANS – Drought has caused the flow of the Mississippi River to run low, compromising its ability to hold the salt water of the Gulf of Mexico at bay and threatening the freshwater supply of Louisiana residents.
This saltwater intrusion of the freshwater supply in New Orleans has caused many to stock up on water, while some find other ways to prepare for the potential contamination of their water supply.
"I feel that I probably will filter my water like I am usually doing, but probably not going to be running to stores. I have backup water from hurricanes," said New Orleans resident Brittain Crull.
Bottles of water. (Bowen Kedrowicz / FOX Weather)
Officials said the cause of this contamination is due to the low rainfall amounts upriver, causing the Mighty Mississippi River to fall to low levels. The river’s ability to flow powerfully into the Gulf of Mexico is critical in protecting the freshwater supply.
"When the Mississippi River doesn’t have enough flow where it gets a certain low flow, it doesn’t have enough force to keep the Gulf of Mexico essentially from coming upstream," said Heath Jones, Chief Operations Division New Orleans Army Corps of Engineers.
SALT WATER THREATENS LOUISIANA DRINKING WATER SUPPLY AMID MISSISSIPPI RIVER DROUGHT
The saltwater intrusion is expected to occur within a few weeks. In the meantime, the U.S. Army Corps of Engineers is building an additional 25 feet to an underwater barrier known as a "sill" in the Mississippi River. Building such a barrier involves pumping up sediment from the river bottom.
U.S. Army Corps of Engineers. (Bowen Kedrowicz / FOX Weather)
This measure helps prevent salt water from reaching the river. According to Jones, salt water is heavier than fresh water, so it sits on the bottom. To keep it at bay, the sill essentially works as a levee until the amount of salt water becomes so high that it breaches the sill.
This engineering feat has historically happened once every 10 years. However, this year marks the second year in a row the sill has had to be built, according to New Orleans Division Army Corps of Engineers Chief of Public Affairs Ricky Boyett.
"The only real fix is rain," Boyett said. "We need to get rain into the Mississippi Valley. We’re a long ways away if the forecast holds, but we are preparing for this to go into December, maybe early January."
Dangerous salt water intrusion continues in lower Mississippi River amid drought
Lower Mississippi River Forecast Center hydrologist Jeff Graschel explains that rains have not made it far enough west to help with the extreme drought conditions in the Mississippi River. As the drought continues, salt water is making its way into the lower Mississippi and threatening the drinking water supply in Louisiana.
Officials said the sill is expected to hold off the salt water for 10-15 days. At that time, salt water from the Gulf may climb over the sill and into the Mississippi River.
According to the White House, President Joe Biden ordered federal assistance for Louisiana after declaring the emergency exists on Wednesday.