Carlsbad sinkhole will take two years to fix
Work to fill in a massive sinkhole on the southern edge of Carlsbad is set to begin next year and will take at least two years to complete, local roadway officials learned this week.
Traffic at the junction of U.S. 285 and Highway 62/180 where the sinkhole exists will have to be detoured to allow the work to proceed, said Tim Parker, the New Mexico Department of Transportation’s district engineer for southeastern New Mexico. Parker spoke to members of the Southeastern New Mexico Roadway Safety Integrated Project at a quarterly meeting Wednesday in Hobbs.
A concrete wall barrier will be constructed along U.S. 285 to the intersection of Highway 62/180, and a new ramp will be built for motorists merging from Highway 62/180 onto U.S. 285. Two-lane traffic in every direction will remain in place throughout the duration of the project, Parker said.
Once begun in January or February 2019, Parker said the $43 million project will proceed 24 hours a day, seven days a week, as workers fill in the sinkhole with 300,000 to 1 million cubic yards of materials with several piers of grout. He said 26 to 28 wells will be drilled over the sinkhole in a grid pattern which will be used to pump materials into the sinkhole.
Parker said other large sinkholes have been filled in, but never on the scale of the one found in Carlsbad. He said a rubble pile possibly exists in the middle of the sinkhole.
“What they’re trying to figure out is when they start construction in January or February of next year is doing more science, dialing it in a little bit better, removing one of the buildings from the site that needs to go away,” Parker said.
The sinkhole is a former brine well, which was closed in 2008 when the ground was deemed unstable. Brine wells hold saltwater for oil and gas operations and leave behind underground caverns.
Parker said an average of 42,000 vehicles a day pass through the junction.
“It’s a real busy intersection, in fact it’s one of the busier intersections in the state, believe it or not, including Albuquerque,” Parker said. “This is big city traffic. We don’t want to change much.”
The sinkhole is situated near the junction of U.S. 285 and Highway 62/180, and is also beneath a canal that supplies water to most of southern Eddy County’s farmers.
Carlsbad Irrigation District manager Dale Ballard has said a collapse of the sinkhole would cut off water to 80 percent of the district’s users for up to three years.