Massman Recognized For Columbia Lock Repairs
by Frank McCormack | The Waterways Journal Weekly
In July 2018, the Vicksburg Engineer District announced an emergency closure at Columbia Lock on the Ouachita River in the northeast corner of Louisiana. District personnel investigating seepage and sand boils at the structure had discovered voids under a lock wall.
Two and a half years prior, a sand boil had developed inside the lock chamber, with water upstream of the lock forcing its way under the miter gate, through the aquifer beneath the lock and up through the lock floor. Unlike many locks that have a heavy, continuous concrete floor, the lock floor at Columbia is made up of a sand and gravel base layer that acts as a filter, with heavy concrete blocks on top to hold that filter in place. The porous floor was intended to allow seepage between the upper pool and lock chamber.
Columbia Lock provides a maximum 18-foot lift between the lower pool to the upper pool.
“In late 2015, there was the sand boil inside the lock chamber floor, so we knew those blocks and the filter system had become compromised and had displaced some of those blocks,” said Lanny Barfield, dam safety officer for the Vicksburg District. “We now had water running under the lock and boiling up into the lock chamber.”
