Research students from the the University of Alabama measure wind speeds as Hurricane Isaac makes landfall, Wednesday, Aug. 29, 2012, in New Orleans, La. Isaac was packing 80 mph winds, making it a Category 1 hurricane. It came ashore early Tuesday near the mouth of the Mississippi River, driving a wall of water nearly 11 feet high inland and soaking a neck of land that stretches into the Gulf. The storm stalled for several hours before resuming a slow trek inland, and forecasters said that was in keeping with the its erratic history. The slow motion over land means Isaac could be a major soaker, dumping up to 20 inches of rain in some areas. (AP Photo/Eric Gay)

Newly downgraded Tropical Storm Isaac plodded its way across Louisiana on the seventh anniversary of Katrina, with officials weighing whether to bust a hole in a levee to relieve some of the water that was spilling over a wall in a rural part of the state Wednesday.

Two men walk in the storm surge from Isaac, on Lakeshore Drive along Lake Pontchartrain, as the storm approaches landfall, in New Orleans, Tuesday, Aug. 28, 2012. (AP Photo/Gerald Herbert)

People and a dog who were rescued from their flooded homes are loaded into a Louisiana National Guard truck, after Hurricane Isaac made landfall and flooded homes with 10 feet of water in Braithwaite, La., in Plaquemines Parish Wednesday, Aug. 29, 2012. (AP Photo/Gerald Herbert)

Drug Enforcement Agency Special Agent Keith Billiot, left, Lanny LaFrance, center, and Sam Maltese, right, battle the wind and rain from Hurricane Isaac while riding in a rescue boat Wednesday, Aug. 29, 2012, in Braithwaite, La. Maltese and his family were rescued from their flooded home. (AP Photo/David J. Phillip)

Residents who were rescued from their flooded homes are transported to waiting assistance, after Hurricane Isaac made landfall and flooded homes with 10 feet of water in Braithwaite, La., Wednesday, Aug. 29, 2012. Isaac was packing 80 mph winds, making it a Category 1 hurricane. It came ashore early Tuesday near the mouth of the Mississippi River, driving a wall of water nearly 11 feet high inland and soaking a neck of land that stretches into the Gulf. (AP Photo/Gerald Herbert)

Homes are flooded as Hurricane Isaac hits Wednesday, Aug. 29, 2012, in Braithwaite, La. As Isaac made landfall, it was expected to dump as much as 20 inches of rain in several parts of Louisiana. (AP Photo/David J. Phillip)

Isaac's winds and storm surge overcomes the seawall and floods South Beach Boulevard in Waveland, Miss., Wednesday, Aug. 29, 2012, the seventh anniversary of Hurricane Katrina hitting the Gulf Coast. (AP Photo/Rogelio V. Solis)

Pedestrians pass a fallen traffic light as Hurricane Isaac makes landfall, Wednesday, Aug. 29, 2012, in New Orleans, La. Isaac was packing 80 mph winds, making it a Category 1 hurricane. It came ashore early Tuesday near the mouth of the Mississippi River, driving a wall of water nearly 11 feet high inland and soaking a neck of land that stretches into the Gulf. The storm stalled for several hours before resuming a slow trek inland, and forecasters said that was in keeping with the its erratic history. The slow motion over land means Isaac could be a major soaker, dumping up to 20 inches of rain in some areas. (AP Photo/Eric Gay)