Lake Tangipahoa at Percy Quin Park is flooding. Its spillways are working, but nearly 10 inches of rain from Hurricane Isaac created two slides on the side of the dam.
"You don't have as much earth there to keep the water back, essentially and so that's a real threat," says Mississippi Department of Environmental Quality Dam Safety Engineer Dusty Myers.
Louisiana National Guard helicopters are placing boulders on the dam to help ensure it doesn't fail. The Mississippi National Guard is also on the scene with bulldozers and trackhoes.
A breech is scheduled to begin Friday and could continue into Saturday.
"We'll remove some of the roadway and allow some of the pressure of the high water to simply go into the fields, lowering the threat," explained Mississippi Governor Phil Bryant at a Thursday press conference.
"We want to control that. We don't want to open up a breech and cause more problems that we do good. So, we have to take our time and do that, and depends on how much rain fall we get coming in and I think the lake level has pretty much stabilized now," explains Myers.
Pumps are also being used to take water out of the Pike County lake, which could breech at any moment.
Bryant says he has talked to Louisiana Governor Bobby Jindal about the dam. Precautions are being taken to protect residents downstream from the 700 acre lake and near the Tangipahoa River should the dam fail.
"Our immediate flood plain would help control that flow. It would not be a wall of water moving toward Tangipahoa parish in Louisiana. As it moved under the bridge, it would then dissipate within the low lying areas that we have designed in Mississippi," explained Bryant.
About 20 nearby homeowners were strongly advised to leave until the controlled breech was completed sometime Sunday. Pike County EMA says some residents did leave their homes.
Copyright 2012 WLBT. All rights reserved. AP contributed to this report.