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.
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.
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.
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."
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.