Behind the scenes at Cantrell Dam in Truth or Consequences: erosion, large drainage tunnel and maintenance limits

Presenter conducted an exclusive behind-the-scenes tour of Cantrell Dam near Truth or Consequences in late July 2025, five years after a devastating flood affected the city and nearby Williamsburg. The presenter described visible signs of storm-driven erosion and a large drainage system running beneath Interstate 25.

From the road to the dam, the presenter said the 2.5-mile route from Capra is “roller coaster-like” and lined with deep powdery sand that can challenge even four-wheel-drive vehicles; the presenter added, “we strongly advise against attempting the trek.” The approach makes the structure’s true scale more apparent than distant views suggest.

At the site, the presenter reported a shallow pool of rainwater near the top and deep cuts and settled silt at the base, which the presenter described as evidence of the force and direction of recent flows. The presenter said Cantrell Dam spans nearly 300 feet with a ridge that drops about 30 feet to the floor where two large drainage tubes are located.

The presenter described the dam’s two primary drainage pipes as having varied openings intended to regulate heavy rainfall. According to the presenter, the city streets department cleans those drainage pipes every two years; scattered debris and high-water marks along the downstream path indicate a powerful surge moved through the system during recent storms.

Near the final curve of the drainage path the presenter found an 8-foot-diameter culvert the size of a truck portal, with a makeshift asphalt track on the tunnel floor. “The 8-ft diameter tunnel is so large that a truck could drive through it,” the presenter said, and added that city crews eventually stopped driving in the tunnel after bolts lining the walls damaged tire sidewalls.

Although the tunnel runs directly beneath Interstate 25, the presenter described its interior as unexpectedly quiet, broken only by bats and graffiti that indicate people have entered the space. From the vantage point above the structure, the presenter said views of Truth or Consequences and Williamsburg are visible across a network of ditches and old infrastructure.

The presenter noted old gabion (rock-filled wire) cages likely dating from the 1960s construction of I-25 and said the dam may have begun as a highway retention wall, though its origins are unclear. The tour provided observational detail on erosion, storm impacts and maintenance limits but did not include statements of policy or formal actions by the city.