Slow-moving Isaac was downgraded to a tropical storm on Wednesday but was still packing a punch, with new evacuations ordered and rescues made when a levee outside New Orleans overtopped. Inside New Orleans, levees and pumps were protecting the city from widespread flooding, but Isaac had cut power to a third of Louisiana’s households and was expected to lash the state with heavy rain and winds into Friday.
In Plaquemines Parish, the storm surge overtopped an 18-mile stretch of levee, sending up to 12 feet of water over the 8-foot-tall barrier. National Guardsmen and residents rescued dozens of people trapped in homes.
“We have flooding, inundated four-to-nine feet in areas,” parish emergency management official Guy Laigast told The Weather Channel. “We’ve got homes that have been inundated.”
“It’s piling that water up on the east side of the Mississippi River,” he added. “All that water is ponding up in that area, and that’s what’s causing the overtopping.”
The area had been under a mandatory evacuation order, but only half of the 2,000 residents reportedly had left ahead of Isaac’s landfall Tuesday.
By Wednesday afternoon, the threat eased on the east side of Plaquemines Parish, but a shift in the wind now threatens the west side, triggering mandatory evacuations there of some 3,000 residents — among them 112 nursing home residents.
With the wind having shifted, officials were also looking at whether to deliberately breach the overtopped levee so that water flushes out more quickly.