FIGHTING SAND BOILS Relief wells coming to repair Buck Chute
Published 11:59 am Tuesday, October 4, 2011
Making the mainline Mississippi River levee strong-er at Buck Chute means reshaping the barrier on its dry side to ensure a stronger structure is in place to protect the Eagle Lake community before the river’s annual spring rise, a lead project manager said Monday.
An emergency berm built on the land side of the levee is being leveled out and enlarged using dirt from marshy areas on the river side. The result, if plans spelled out by the Corps of Engineers hold, will be a 1,700-foot berm with 30 relief wells to ease pressure from seep water deep below ground.
“It’s pretty much cut and dried,” Corps project engineer Jason Overstreet said. “It’s pretty much reshaping the berm and putting in the relief wells.”
In August, Thibodaux, La.-based Phylway Construction LLC was awarded a $3.1 million contract to handle two projects fast-tracked by the Mississippi River flood of 2011 — the Buck Chute berm and a barrier across 300 feet of weak landside levee at Lake Albemarle. Both are expected to be done by late January, as per the 120-day contract term.
Buck Chute, west of Eagle Lake, forms the southernmost point of the mainline levee system in Mississippi — the most vulnerable point in the levee system in the state due to chronic seepage from the river trying to find a way to its former stem. Work to build a sand berm and relief wells was scheduled in the spring but scrapped when hunters found new sand boils during the river’s first spring rise in March. A 2-acre berm was built, minus the wells, and the Muddy Bayou Control Structure was opened to elevate the lake about 12 feet above normal stages to ease water pressure on the levee.
Once installed, the wells will relieve water pressure by containing the water and filtering the soil particles that can cause sand boils on the traditional trouble spot.
About seven miles north at Lake Albemarle, soft sections of landside levee gave way May 16, three days before the river crested in Vicksburg at 57.1 feet, or 14.1 feet above flood stage and 0.9 foot higher than the Great Flood of 1927. Five sand boils nearby were found and sealed with about 18,000 tons of sand and rock in the following week.
Brush was cleared at Albemarle on Monday to move power lines near the work site, Overstreet said.
The levee system spans 163 miles in the zone maintained by the Board of Mississippi Levee Commissioners.