Saltwater Intrusion

Construction has begun on a saltwater sill near Myrtle Grove to help mitigate the effects of saltwater intrusion up the Mississippi River.

In this episode, we explore a growing threat to our freshwater supplies in coastal regions all over the country. With climate change, we are experiencing sea-level rise and more frequent droughts, both of which make it easier for saltwater to creep into places we don’t want it.

It’s the second year in a row that extreme drought has caused a shrinking channel, forcing the U.S. Army Corps of Engineers to dredge later in the season than normal.

The saltwater wedge slowly creeping up the Mississippi River is no longer threatening drinking water for Louisiana’s biggest metro area – but officials in Orleans and Jefferson parishes are moving forward with mitigation plans, in case forecasts shift yet again.

For more than three months, residents in south Plaquemines Parish didn’t have safe drinking water. The cause? Intruding salt water from the Gulf of Mexico.

Rainy weather is set to return to the Gulf Coast after an unusually dry hurricane season that’s contributed to crop failures, saltwater intrusion and record-breaking wildfires.

St. Bernard Parish is no longer expected to be affected by the saltwater wedge moving up the Mississippi River, joining its upriver neighbors.

The U.S. Army Corps of Engineers says salt levels should be within the safe-drinking threshold set by the Environmental Protection Agency when — and if — the wedge reaches New Orleans.

Exactly which steps schools will need to take — and when — is still unclear, as city, state and federal agencies race to get ahead of the saltwater wedge.

Communities in southeastern Louisiana are bringing fresh water — by barge and by pipeline — to their local water treatment plants, to dilute the briny water brought in by the saltwater wedge.