The U.S Army Corps of Engineers received assistance Thursday from area fire departments and various Monroe County emergency management personnel in tending to several sand boils detected near an agricultural levee at Reichmann Road and Merrimac Road north of Valmeyer in the far west-central portion of Monroe County.
A local farmer first observed the sand boils Thursday and notified emergency officials.
Officials at the scene stressed that the situation is not uncommon with the current river elevation, which was at 39.6 feet as of 11:30 a.m. Thursday. The river crested Tuesday at 40.52 feet in St. Louis, which is considered major flood stage.
“We’re just gonna try and take care of them. No need to panic,” said Brian Mehrtens of the Columbia Levee and Drainage District.Geotechnical engineer Mario Guerrero of the U.S. Army Corps of Engineers assesses a standpipe culvert that was placed on one of the sand boils Thursday. The water pooled to the top of the culvert pipe within minutes.
Sand boiling is occurring up and down the length of the metro-east levee system, although Reichmann Road is the only known affected area so far in this county. It is a result of hydrostatic pressure of the high water on the outside of the levee. This forces water through the ground and it rises to the surface. Left undetected, sand boils could eventually lead to a levee collapse.
“Everything’s manageable at this point,” Corps sector engineer Keith McMullan assured.
He and fellow Corps members David Gordon, Janet Ulivi and Mario Guerrero were on scene, with a plan to surround the most serious of the sand boils closest to the levee using a ring of sandbags. Other smaller sand boils in the area were being treated with “standpipes,” or portions of metal culverts used to apply pressure.
The first sandbags used Thursday were leftovers from the Flood of 1993, trucked in from a county storage yard adjacent to Rock City in Valmeyer. Once those were used up, volunteers were put into action and more bags were filled with sand to be trucked to the area of the sand boils.Volunteers assist Corps officials in creating a sandbag ring around a cluster of sand boils detected near the levee by Reichmann Road on Thursday.
Firefighters from Waterloo, Valmeyer, Maeystown and Columbia assisted in the volunteer effort, as did Monroe County Highway Department employees and others affiliated with the Monroe County Emergency Management Agency.
Corps official Keith McMullan told the Republic-Times he was out assessing the situation Friday morning, and it appears efforts to contain the sand boils were successful.
“All of them have shut down, so that’s great,” he said. “They are stagnant, with no movement of materials. We believe we have it under control. “
McMullan added that with the continued river recession, the risk of similar incidents is diminishing day by day. The river measured at 38.6 feet this morning in St. Louis, and was expected to drop to 35.5 feet on Sunday.