LOS LUNAS — More than five months and about $5 million dollars later, the N.M. 6 river bridge in Los Lunas is back to being fully operational following a detrimental collapse near the bridge.

“Everything is permanently fixed in that area, which hadn’t been touched since 1989. Hopefully, that will provide more stability in the area and will continue to keep traffic flowing,” said Kimberly Gallegos, public information officer for the New Mexico Department of Transportation District 3.

On the evening of May 13, a sinkhole formed due to erosion around a culvert that runs under Main Street on the east side of the Los Lunas river bridge. This caused a section of sidewalk and dirt shoulder to abruptly collapse right as 40-year-old Sergio Marquez biked over it, trapping him in the process.

Marquez’ son, Felix, who was biking with Sergio thankfully did not fall in, but he could not pull his dad out of the sinkhole alone. Fortunately, three passerbyers took notice and stopped to help Felix pull Sergio out of the strong river current within the sinkhole, injured but alive.

The collapse occurred where the Lower Peralta Drain culvert passes under the street east of the Rio Grande. Water in the drain had been extremely high due to unusually high flows in the river. This, accompanied by higher than normal groundwater levels that exceeded the scope of the culvert, is what’s thought to have been the main cause of the erosion which led to an eventual collapse.

Julia M. Dendinger | News-Bulletin photos
Part of the sidewalk on the north side of Main Street in Los Lunas collapsed after a sinkhole opened up under the westbound side of the roadway as it approaches the bridge over the river.

The village of Los Lunas, responsible for the utilities that run beneath and around the bridge, paid $32,000 total following the incident.

Los Lunas Public Works Director Michael Jaramillo said this went toward hiring a contractor to assist village personnel in turning off and adjusting water services in the area.

“Once they isolated the water line and redirected services to a few property owners, NMDOT took over the remaining repairs,” said Jaramillo.

NMDOT, who owns N.M. 6 and the culverts beneath, paid for all other associated repair costs.

Gallegos said the repaired sidewalk along the river bridge is now safe to walk on. Also, the new 72-inch diameter reinforced concrete culvert placed in both the east and westbound sides of the roadway should prevent future sinkhole scenarios.

This concrete culvert, estimated to have a 100-year lifespan, replaces the previous 54-inch corrugated metal culvert, which was about 70 years old with 30-year-old extensions on both ends.

Gallegos said the culverts on the west-bound side were not in any trouble, but they decided to replace those as well to ensure consistency on both sides of the roadway.

“These ones will definitely hold more capacity and be able to better assist with changing water flows,” she said.

Gallegos said part of why construction repairs took as long as they did was because of all the de-watering that took place. Water needed to be cleared out of the area to see the full extent of the damage and to complete repairs.

“We had to release and hold back some of the water in the reservoir at Cochiti Lake and it only went down about 2 inches,” said Gallegos. “So when that didn’t work, that’s when we had to bring in these specialized pumps from out of state and that took about a month, maybe longer.”

Large pumps pull water out of the Lower Peralta Drain to dewater the area that collapsed under a sidewalk on the east side of the Los Lunas river bridge.

After the area was de-watered, they then had to wait for everything to dry out. Once dried, Gallegos said a crew investigated that entire area with cameras to see what they were up against.

They then formulated and executed a plan to replace the existing culvert with four separate concrete segments which make up the entirety of the new culvert.

According to an Albuquerque Journal article by Colleen Heild, this incident spurred NMDOT to evaluate other culverts it’s responsible for along the Rio Grande, especially along the river from near Bernalillo south to Socorro.

Gallegos said the NMDOT team dedicated to this task has been collecting culvert data from around the state since the summer to see what areas need to be addressed and which ones are at the most risk.

In Valencia County, Gallegos said they had a couple situations around Jarales recently, but those are now resolved. She believes the rest of the infrastructure in the county is in sound condition.

“Our crews continue to monitor and evaluate our bridges and culverts in the area, as of now there are no additional areas of concern,” she said.

Gallegos is appreciative of the community’s patience during this unforeseen emergency.

“We understand it was a hurdle to get through,” she said. “With the village expanding there’s a lot more people on the road and we realize it was an inconvenience, but we did the best we could to get it done in the amount of time we did.”

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Felina Martinez was born and raised in Valencia County. She graduated from the University of New Mexico in 2021. During her time at UNM, she studied interdisciplinary film, digital media and journalism. She covers the village of Los Lunas, Los Lunas Schools, the School of Dreams Academy and the town of Peralta.