An alleged plot by a Mexican drug cartel to blow up a dam along the Texas border — and unleash billions of gallons of water into a region with millions of civilians — sent American police, federal agents and disaster officials secretly scrambling last month to thwart such an attack, authorities confirmed Wednesday.
Whether or not the cartel, which is known to have stolen bulk quantities of gunpowder and dynamite, could have taken down the 5-mile-long Falcon Dam may never be known since the attack never came to pass.
It may have been derailed by a stepped-up presence by the Mexican military, which was acting in part on intelligence from the U.S. government, sources said.
The warning, which swung officials into action, was based on what the federal government contends were “serious and reliable sources” and prompted the Department of Homeland Security to sound the alarm to first responders along the South Texas-Mexico border.
Mexico's Zeta cartel was planning to destroy the dam not to terrorize civilians, but to get back at its rival and former ally, the Gulf cartel, which controls smuggling routes from the reservoir to the Gulf of Mexico, said Zapata County Sheriff Sigifredo Gonzalez, head of the Southwest Border Sheriff's Coalition, as did others familiar with the alleged plot.
But in the process, massive amounts of agricultural land would stand to be flooded as well as significant parts of a region where about 4 million people live along both sides of the U.S.-Mexico border.
The dam along the lower Rio Grande was finished in 1954 as part of a joint U.S.-Mexico project to collect water for flood control, hydroelectric power and water for drinking and agriculture.
Gonzalez's agency was among many that responded, as did the U.S. Border Patrol, the Texas Department of Public Safety and even game wardens, who put more boats on the water.
Citing security concerns, neither Homeland Security nor DPS commented.
“We trust that DPS and their federal and local law enforcement partners are constantly collecting intelligence and monitoring all threats to Texas and taking the appropriate action to protect our citizens from those who would do us harm,” said Gov. Rick Perry's deputy press secretary Katherine Cesinger.
Law enforcement officials huddled at the dam, near Rio Grande City, to discuss the threat and how to stifle it, said an officer who attended the meeting.
Officers interviewed by the Chronicle gave the warning varying degrees of credibility. They noted that among the Zetas ranks are Mexican military defectors who were trained in special forces tactics, including demolition.
Special cameras were set up along the dam, which has six 50-foot-tall steel gates, and lawmen hid in brush.
A Mexican military spokesman, who spoke on the condition of anonymity, said he had not heard of any threat to the Falcon Dam and expressed doubt that the Zetas would try such an attack.
“This isn't the way these groups operate, they have never attacked installations like that,” he said.
Rick Pauza, a spokesman for Customs and Border Protection, in Laredo, said the port of entry at the dam had been at a heightened alert due to violence in Mexico.
The attack may have been thwarted in Mexico. It raises the fear of what the powerful cartels could do.
“It would have been a hell of a disaster,” said Gene Falcon, director of emergency preparedness for Starr County, site of the dam. “There was plenty of concern.”
With handbills and bullhorns, members of the Zeta cartel are said to have warned the civilian population on the Mexican side of the river near the dam to get out of the area, according to residents and intelligence information from law enforcement officials.
A border law enforcement official told the Chronicle the warnings originated in part by the seizure of small amounts of dynamite near the dam, and the discovery of a copy of the alert on the Mexican side of the border.
Capt. Francisco Garcia, of the Roma (Texas) Police Department, said there was no way to know what the traffickers were capable of doing, but bringing down the dam would require nearly a tractor-trailer full of dynamite.
“As far as blowing it up — making it fall apart completely — it would have to be something like 9/11,” he said. “By the time they'd start to do something, there will be so much law enforcement there it'd be ridiculous.”