Corps: Lessons learned will help with this flood
Published 8:45 pm Saturday, January 2, 2016
Personnel at the U.S. Army Corps of Engineers are heading into this month’s anticipated flooding of the Mississippi River and its tributaries feeling confident.
“Most of what we learned from the 2011 flood, we are going to apply this time,” said Greg Raimondo, chief of public affairs for the Vicksburg District U.S. Army Corps of Engineers.
“For example, during the 2011 flood, we had a significant problem up in Buck Chute near Eagle Lake. We had huge sand boils,” he said. “Using relief wells and seepage burms, we won’t have the need to raise the water level of Eagle Lake this time.”
Raimondo explained a sand boil is created because the water is higher on the riverside than the landside of the levee, which creates pressure against the levees.
“What happens is the water tends to percolate under the levee and will pop up on the land side. As long as it’s flowing cleanly, we’re OK. If it’s flowing dirty, that means it’s taking material with it and is undercutting the levee. If we have a big enough problem, you could have a levee collapse, and that would be horrible,” Raimondo said.
During the 2011 flood, because of the number of sand boils, the Corps had to raise the level on Eagle Lake to put water on top of those sand boils to help relieve the pressure on the levee.
“Now we know we need to use relief wells, which give the levee a release point,” he said.
Investment in infrastructure along the Mississippi River and its tributary system pays back at a rate of about 44 to 1, Raimondo said.
“In 2011, only one person lost his life. Compare that to what happened in 1927. You can see the investment infrastructure has been well worth it. Every time we have a flood, that investment continues to pay dividends,” he said.
During times of flooding, the Corps provides technical advice and some manpower to levee boards, including helping to patrol the levees to look for slides and sand boils. In addition, the Corps provides technical assistance to the city of Vicksburg, working with the city engineer, and the Warren County Emergency Operations Center.
The EOC was activated on Thursday, meaning it opened for business and will stay open until any threat has passed, he said.
The Corps may help provide pumps, sandbags or Hesco bastions, which are cages filled with geotextile inside and can be filled with sand and linked together.
The Corps levee flood fight teams will be in place beginning next week, Raimondo said, probably by Jan. 4, and will be working out of two locations: at Lake Village in its northern sector and in its southern sector in Vidalia, La.
He said the “levee stompers” — affiliated with levee boards — are out in full force during floods.
“They are climbing all over the levees, looking for sand boils and slides. You’ll see them out there on ATVs,” Raimondo said.
One difference he pointed out between the 2011 flood and the one expected to crest here on Jan. 16 is the drought conditions in 2011.
“We were in a drought in 2011. You could stand on top of the levee and see water for miles on one side, then look on the dry side and see a farmer irrigating his fields,” Raimondo said. “This time we’ll be fighting a winter flood. There’s lots of water out there on the ground as it is. That may make it a little harder to find the sand boils. It may be a little more challenging, but we have known places where we expect to see these things.”