All branches of the U.S. Dept. of Defense (DOD) combined forces to attack an engineering problem that holds the lives of 70,000 people in the balance. Hurricane Maria’s heavy rains caused Puerto Rico’s 984-ft-long, 120-ft-tall hydroelectric, earthen Guajataca Dam to overflow its banks on Sept. 22, damaging its spillway and forcing federal engineers to get creative in their approach to stabilizing the hard-to-reach structure.
“When we arrived on site it was four days after the hurricane and approximately 50% of the spillway channel was eroded and gone, with 2 feet of water flowing through the spillway,” says Dan Blaydes, lead engineer for dams and levees, Jacksonville District, U.S. Army Corps of Engineers, which provided technical support to the owner, Puerto Rico Electric Power Authority (PREPA), and its contractors. Another 10% of the 646-ft-wide spillway channel was lost during the ensuing 20 days that it took crews with the Corps and DOD to stabilize the dam, says Blaydes. “Most of it happened very quickly after the hurricane and the flows were super high,” he says.