Can Dam Failures Like Puerto Rico's Guajataca Be Prevented?

Deepening Crisis

Friday afternoon Puerto Rican officials urged 70,000 people in the vicinity of the Rio Guajataca, including the northwestern communities of Quebradillas, Isabela, and the surrounding areas, to evacuate immediately. The 37-meter (120-feet) high Guajataca Dam was threatening to fail, its collapse characterized by the authorities as “imminent.”

“This is an EXTREMELY DANGEROUS SITUATION. Buses are currently evacuating people from the area as quickly as they can,” the National Weather Service (NWS) in San Juan said in a statement. Warnings were also issued via social media.

Since Hurricane Maria devastated the island, there have been at least 13 deaths, and the entire U.S. territory remains without power for the foreseeable future. The storm was the second hurricane to hit the island this month, and the strongest in 90 years. The governor said that Maria was the worst storm Puerto Rico had seen in a century.

Early Warnings Save Lives

The dam, situated in northwest Puerto Rico at the northern end of Lake Guajataca, threatens to spill 11 billion gallons of water into nearby populated areas. The dam's slow failure, which continued into Saturday morning, forced NWS to urge residents via Tweet to avoid the water's path and move to higher ground.

According to federal reservoir data, between Tuesday and Wednesday the lake rose more than a meter (three feet) as the category 4 storm pummeled the island. The agency has the ability to warn residents thanks to its early warning system, the kind of technology scientific agencies all agree saves lives in various contexts.

At the time of this writing there is still a flash flood warning in effect. “This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order,” the NWS warned in the alert.