South Louisiana was hit with a massive amount of rain late last week that has had a devastating impact on the state and its residents.

In some areas of Louisiana the event is being called a “1,000-year rain” because there was a 0.1 percent chance of that amount of raining falling in any year, Ricky Boyett, Chief Public Affairs U.S. Army Corps of Engineers New Orleans District said. Other areas saw a “100-year rain” meaning rainfall amounts had a 1 percent chance of happening any given year.

“It’s an extremely rare event where you had areas of up to 25 inches of rain in a three day period. Sometimes they were getting as much as 3 inches an hour. That’s the primary cause of the flooding is the rainfall in such a massive amount,” Boyett said.

He said state officials are still evaluating data to determine the reason for the amount of rain.

“The state of Louisiana is working on looking at areas that have flooded,” Boyett said.

An official from the Governor’s Office of Homeland Security and Emergency was not available for comment.

“They have the lead on this project,” Boyett said, adding the Corps role has been to help with the response. “We’re making sure we have ample pumps and sand bags available.”

He said whenever there is an emergency, especially water related, and the federal government declares it an emergency the Corps can supply technical assistance, supplies and resources.

Greg Raimondo, Army Corps of Engineers Vicksburg District Public Affairs Office Chief, said the Vicksburg District of the Corps has not been impacted by the onslaught of water.

“We have no structures down there in that area,” Raimondo said.

Since the sheer amount of rain has been the main cause of the flooding, Ramindo said he didn’t know of any way for it to have been prevented.

“That’s a flat area down there so it doesn’t drain, it’s not meant to drain like that. They had 15 to 20 inches of rain in some places,” he said. “I’m looking at the map, and I know that we have no flood damage risk reduction projects down in that area. The rivers and streams were all at normal levels.”

He said the amount of rain was similar to an event in March called a 600-year event where a line of rain cut diagonally through Louisiana up to southeast Arkansas and into northwest Mississippi.

“That storm produced tremendous, what we call, backwater flooding,” Raimondo said, defined by the National Weather Service as upstream flooding caused by downstream conditions.

Typically flooding comes from heavy rains occurring upstream causing the river to rise downstream, he said, which is the kind of flooding levees are suppose to protect against.

“The kind of flash flooding we’ve seen from the March event and this event, there isn’t really anything that can be done,” Raimondo said.

President Barack Obama signed a federal disaster declaration Sunday for Louisiana to aid the impacted areas. The next step will be to begin cleanup.