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

The sill, or underwater levee, is being built for a third year in a row to head off the potential for New Orleans area drinking water to be threatened.

As the Mississippi River water level lowers, the possibility of a saltwater intrusion increases, and for the third year in a row, southern Louisiana will be facing one.

The Rundown Army Corps builds a temporary barrier on Mississippi River bed to block upstream movement of salt water that threatens municipal drinking water. EPA announces $7.5 billion in low-interest financing for water infrastructure.