Gov. Bobby Jindal's cheif coastal advior said a decision will be made later today on whether the levee on the east bank of Plaquemines Parish should be deliberately breached to relieve flood water pressure on it from Hurricane Isaac.
This action would be the last resort if other means to relieve the pressure on the levees fail.
Jindal said that between nine and 40 people have been trapped on the east bank and are being rescued by the National Guard.
Attention is focused on the Caernarvon fresh water diversion project, a coastal restoration project built by the Army Corps of Engineers that is now operated by the state.
During normal times, the state diverts water from the Mississippi River through a large pipe that runs through the east bank levee at Caernarvon so that the sediment from the Mississippi flows into the marshes to help rebuild the sinking land.
But with Braithwaite under water, officials are considering running the pumps in reverse so that the storm surge water from Hurricane Isaac that overtopped the back levees drains out through the pipe into the Mississippi River, where it can flow out to sea.
Heath Jones, an emergency manager with the Army Corps of Engineers, said that officials made such a maneuver in 2008 and it worked. But in this case, the state might need to let the level of Mississippi River fall before it can reverse the pumps. If the level of the river is higher than the flood water in Braithwaite, opening the pipe in the other direction would only compound Plaquemines' problems because water from the River would flow into the parish.
Earlier, state emergency management officials said that the 8-foot-tall non-federal levee near the Braithwaite community was being overtopped with flood water and they levee was being "scoured away."
There has not been a breach yet," Jindal said at a noon news conference. "We are considering a deliberate breach to relieve the water pressure."