Here's the latest on saltwater intrusion threatening New Orleans drinking water in Louisiana
A saltwater wedge working its way up the Mississippi River is on track to contaminate New Orleans' drinking water in late October, which has federal, state and local officials scrambling to deliver alternative supplies of fresh water to southeastern Louisiana.
Last week, President Joe Biden approved Louisiana Gov. John Bel Edwards' request for an emergency declaration, unlocking resources to address the crisis.
The saltwater intrusion already has compromised the drinking water supply in the most southern rural southeastern parish of Plaquemines, but it's expected to arrive in Louisiana's signature city on or near Oct. 28.
Edwards convened a working group meeting Friday with the Governor's Office of Homeland Security and Emergency Preparedness, the U.S. Army Corps of Engineers and officials from Orleans, Jefferson, Plaquemines and St. Bernard parishes.
"We will get through this just as we have with other emergencies, and that is by working together," Edwards said. "There are four parishes in the country impacted by this event, and there is no doubt that we will be able to satisfy the needs of those communities.”
The saltwater wedge from the Gulf of Mexico is crawling along the riverbed because of low water and insufficient rain. Normally, the flow from the Mighty Mississippi is enough to flush the saltwater back into the Gulf of Mexico.
Similar intrusions have happened before, but this wedge presents the greatest threat to the fresh water supply since 1988.
Last month the corps began construction on a sill, or underwater levee, to slow the intrusion, but it won't completely halt the wedge's advance.
Only an increase in rain in the upper Mississippi River Valley far north of Louisiana will create enough flow to flush the salt back into the Gulf of Mexico.
"A lot of good work has taken place thus far, and I’m grateful for it, but we still have more work to do,” Edwards said. “The weather forecast indicates minimal rain for the next two weeks, and if there is any potential increase in the upper Mississippi Valley it will still take some time to reach our state. The mitigation measures in place are still very necessary, and we are continuing to study all additional options that can be used to address this ongoing situation. The (corps) is making progress daily on augmenting the sill."
In the meantime, pipelines are in the works to pump fresh water from farther up the Mississippi River to New Orleans and other communities where the water supply could become contaminated.
Those pipelines are expensive - perhaps $200 million or more - but the emergency declaration means much of the expense could be funded through the federal governments.
Millions of gallons of fresh water are being taken by barges to treatment facilities in impacted areas, and another option could be to transport fresh water using vessels larger than barges.
The corps has told officials to prepare to deal with the intrusion for at least three month unless significant rainfall occurs.
Greg Hilburn covers state politics for the USA TODAY Network of Louisiana. Follow him on Twitter @GregHilburn1.
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This article originally appeared on Shreveport Times: Saltwater wedge threatens New Orleans drinking water
