This summer Truth or Consequences experienced two major disasters within 40 days—a fire and then a flood—which tested and revealed the area’s level of hazard preparedness.
Our two-part series, “Fire and then Flood Show Prevention Could Have Mitigated Extent of Damage,” examines the circumstances surrounding these emergencies and assesses lessons learned. The first story in the series, published last Friday, covered the Mims Lake fire that began June 17 and ended June 20. Part 2 of the series offers a similar evaluation of the July 26 rain event and the infrastructure malfunction that contributed to extensive flooding in the S. Broadway area.
COSTLY LACK OF MAINTENANCE
Cantrell Dam wasn’t on anyone’s radar until the July 26 deluge gave it importance. The partial breach of the dam, located on Bureau of Land Management property north of Interstate 25 about 1.5 miles north of the Williamsburg exit, contributed to extensive flooding downstream in Williamsburg and western Truth or Consequences.
Maintenance of the dam—for which the City of Truth or Consequences has tacitly accepted responsibility—was inadequate. Erosion and sedimentation contributed to the dam’s overtopping at its eastern and western ends, which released storm waters directly toward the two communities it was built to protect.
T or C is seeking natural-disaster relief for flood damages to its facilities estimated by City Manager Morris Madrid at “less than $750,000” at a Sept. 9 commission meeting. Madrid also sought permission to apply for a $750,000 grant from the New Mexico Finance Authority to repair Cantrell Dam at the Sept. 23 commission meeting.
STATE INSPECTION CONFIRMS DAM’S BREACH
It is impossible to accurately quantify how much rain fell over a very short time on July 26. The National Weather Service, which uses measurements from the Truth or Consequences Airport, sent out a flood warning that up to 2.5 inches had fallen by 5:30 p.m.
But Williamsburg, about 10 miles south, was hit much harder.
KOB 4 and other news outlets said up to 5 inches fell within an hour around Williamsburg, relying on verbal reports from eyewitnesses.
This reporter lives in Williamsburg and can attest this estimate is fairly accurate. But how much of the rising water was from localized rain and how much was from water normally held back by Cantrell Dam cannot be separated out and measured.
Sierra County Emergency Manager Paul Tooley, in an interview with Ryan Laughlin at KOB 4 on July 27, said, “We found a small dam up in that area that actually got breached. It got deep enough there—about 20 feet, and was pouring water all the way down Hyde Street. All the way into the ball fields down towards the river.”
Several homes were damaged, but no one was hurt, according to Tooley.
His statements were refuted by Madrid and Mayor Sandra Whitehead at the Aug. 12 city commission meeting. “The dam didn’t breach,” they insisted.
Given Madrid’s and Whitehead’s statements, Tooley, understandably, did not want to be interviewed for this article.
Besides working for the county as the emergency manager, Tooley is also T or C’s fire chief. His professional assessment that the Mims Lake fire could have been prevented was similarly refuted by Madrid at the June 24 city commission meeting.
However, Tooley’s assessment that the Cantrell Dam’s malfunction was a prime cause of the subsequent flood damage was affirmed by the Office of the State Engineer’s Dam Safety Bureau.
CAUSES OF THE BREACH
Dam Safety Bureau Chief Charles Thompson sent an engineer, James Head, to examine four “jurisdictional” and two “non-jurisdictional” dams in Truth or Consequences on July 30. Most of Thompson’s 11-page report was taken up with Cantrell Dam.
Thompson’s report is dated Aug. 14. He addressed it to Madrid and Williamsburg Mayor Deborah Stubblefield and sent copies to the state Disaster Recovery Manager Rosalita Whitehair, among other state and federal officials.
Describing Cantrell Dam as a “non-jurisdictional floor retardation dam,” Thompson wrote: “This structure experienced a very substantial uncontrolled flood release that resulted in the flooding of downstream residential areas located within the town limits of Williamsburg, New Mexico.”
Cantrell Dam is not inspected and overseen by the Dam Safety Bureau, because it is too small to fall under their jurisdiction. But the Dam Safety Bureau does have the authority to make the responsible entity fix “dangerous works,” which Thompson made clear in the report.
Non-jurisdictional dams are less than 25 feet high and hold back less than 15 acre feet of water. If a dam’s height is six feet or lower, it must hold back more than 50 acre feet of water to be considered jurisdictional by the OSE.
Thompson’s report estimates the Cantrell Dam is about 20 feet high, 310 feet long and its flood detention pond holds less than 15 acre feet of water.
Because Cantrell Dam is non-jurisdictional, there is little documentation on it. Thompson’s report said local sources think it was built “under the supervision of the Natural Resources Conservation Service.”
It shows up on United States Geological Survey maps in the early 1960s, Thompson wrote.
Tooley said the county queried the Bureau of Land Management, since the Cantrell Dam is on BLM land, but it, too, had no documents.
The Sierra County Sun submitted a public-records request to the City of Truth or Consequences, asking for any documents revealing what agency built the dam, what it was designed to do and how it was handed over to the city, but “no such documents exist” was the response.
Unable to rely on government documents for the dam’s design or holding capacity, Thompson looked at Google Earth maps to compare the dam’s post- and pre-flood condition.
The “original storage capacity, (currently unknown), is significantly reduced due to sediment accumulation,” Thompson discovered.
In addition to the storage capacity being diminished, Thompson noted erosion problems that contributed to the dam’s malfunction on July 26.
The greatest erosion was at the “right downstream groin,” Thompson said, which would be the left side of the dam, viewing it from I-25.
To the far-right side of the dam, Thompson said, is a combination access road and spillway, which showed “severe” erosion in 2015 Google Earth maps.
As a result of the erosion on the left and right sides of the dam, as well as the sedimentation limiting water retention, water not only went over the right-side spillway, it also overtopped the left side of the dam, Thompson said.
T OR C’S “TIMELY” REHABILITATION OF DAM STRONGLY RECOMMENDED
The dam’s “partial breach,” Thompson said, in a Sept. 29 interview, caused considerable damage to the I-25 culvert that runs underneath the highway about 200 yards away. In his report he warned the New Mexico Department of Transportation should be notified.
Severe erosion in a third spot on the Cantrell Dam also concerned Thompson. On the left side, near the bottom (when looking from I-25) are two “corrugated metal pipe outlet conduits,” he said. The “headcuts” caused by water streaming from the pipes are visible in the 2015 Google maps.
The erosion under the outlet pipes “will eventually result in total failure of the dam if timely rehabilitation efforts to control additional erosion are not taken,” Thompson said.
Thompson said he didn’t know if Truth or Consequences or Williamsburg was responsible for maintaining the dam, but “recommended that the owner of Cantrell Dam make the necessary timely repairs and perform due diligence with regard to maintaining the dam and the associated appurtenances (spillway and outlet works) to ensure that the structure performs properly.”
The City of Truth or Consequences is responsible for maintaining Cantrell Dam.
Madrid, at the Aug. 12 city commission meeting, didn’t explain or provide documents demonstrating city responsibility, but treated it as a given by including Cantrell Dam among 15 other sites for which the city is seeking disaster-relief funding.
The city commission held an emergency meeting July 29 to declare a disaster, a prerequisite for requesting state and federal funding.
Madrid hired the city’s on-call engineering firm, Wilson & Company of Las Cruces, to do the city’s assessment of flood damage. Funding will only be provided for “new damage,” he said, that is, damage caused by the flood, not pre-existing damage caused by neglect of structures. Therefore, it is essential the city demonstrate it adequately maintained Cantrell Dam.
Wilson & Company, during its Aug. 12 presentation to the city commission, claimed repeatedly the city had good maintenance records for various structures. However, maintenance records requested and received by the Sierra County Sun for Cantrell Dam were scant and prove nothing.
The city provided an unnamed person’s hand-written notes, dated “June/19,” the 19 possibly referring to the day or the year. The notes are headed, “Mud Mountain Dam Project,” which is the wrong dam.
Pictures of Cantrell Dam were also among the Inspection of Public Records Act documents supplied to the Sun as maintenance records. They are undated, but two have hand-written notes on top of the image referring to the flood damage. Post-flood pictures are not proof of prior maintenance.
There is no way to know if the other photos pre-date the flood, as they lack dates and the names of their authors.
The Sierra County Hazard Mitigation Plan, which the city adopted, along with Sierra County, Elephant Butte and Williamsburg, in 2018, will not help the city demonstrate it maintained Cantrell Dam.
Adopting a Hazard Mitigation Plan is another prerequisite for receiving Federal Emergency Management Agency or state emergency management funding after a flood or disaster.
The 2018 plan names and plans for disasters resulting from failure of only the Elephant Butte and Caballo dams.
During the Sept. 9 city commission meeting, Madrid said Wilson & Company’s assessment of damage was “under $750,000,” and therefore federal disaster-relief funding “was unlikely.”
At the following city commission meeting on Sept. 23, Madrid appeared to reverse himself on what happened at Cantrell Dam. After denying Tooley’s assessment the dam breached, Madrid asked the city commission’s permission to submit a completed $750,000 grant application to the New Mexico Finance Authority for the dam’s “design and rehabilitation.” The dam needed to be fixed, he said, “to provide flood protection for the west side of the city.”
The city commission approved the grant application with no comment or questions.
The Sun asked each city commissioner to comment on the city’s switch from denying the dam had malfunctioned to supporting a $750,000 fix for the Cantrell Dam. No commissioner responded.
In a Sept. 29 interview, Thompson said he had not heard from the city about his report. When the Sun told him of the grant application to fix the dam, he was pleased. “It’s a good outcome.”