Puerto Rico's faltering Guajataca Dam was completed when Calvin Coolidge was president. It is one of 38 dams in Puerto Rico, and according to an Army Corps of Engineers inventory, every single one of them has been rated as having a "high hazard potential."
Yet Guajataca hasn't been inspected since 2013, according to the National Inventory of Dams, significantly longer than is ordinarily required of dams with high hazard potential.
Now the 120-foot wall of the earthen Guajataca Dam — finished by the Puerto Rico Electric Power Authority (PREPA) in 1927 — has fissures that triggered evacuation orders for thousands of people who were scrambling to deal with the devastation of Hurricane Maria. Water has been pouring out of one section of the large reservoir into small neighborhoods down in the valley.
A high hazard rating reflects the damage that could happen from a dam's failure, and it is not a commentary on the condition of a dam. Nonetheless, one safety expert said he was surprised by the long gap between inspections at the dam.
"Since this is clearly a high hazard dam (one for which loss of life is likely if the dam were to fail), it would be typical for an inspection of some type to be done once every one or two years," John W. France, vice president for the dams and hydropower technical practice of the engineering firm AECOM, said in an email.
Those inspections are carried out by the Puerto Rican government; 80 percent of dams in the United States are inspected by state governments.
Although France said he was not familiar with Guajataca, he said the four-year gap in inspections violates common practice in most of the United States. He said that "most state dam safety programs in the United States require a physical (visual) inspection of a high hazard dam on an annual basis."
Yet five of PREPA's 16 dams have not been inspected since 2013, and one has not been inspected since 2012, according to the National Inventory of Dams.
The Association of State Dam Safety Officials said in a recent report that the percentage of state inspections declined steadily from 1999 to 2015, when just 80 percent of the high hazard dams were inspected. In 2015, two of Puerto Rico's dams were rated "poor" and four "fair," according to the report. One was not rated at all and the rest were "satisfactory."
The 90-year-old Guajataca Dam created a lake 2½ miles long and as much as a mile wide in the scenic northwest part of Puerto Rico. It has long been considered a recreational attraction, where people go camping, hiking and fishing alongside rain forests. Still owned by PREPA, the dam has supplied hydroelectric power, irrigation and water needs.
But little investment has gone into infrastructure in Puerto Rico, which is in bankruptcy to restructure its more than $72 billion in debt. The biggest single chunk of that debt belongs to PREPA, the bankrupt state-owned utility.
That could pose problems for the commonwealth's dam infrastructure. Most of Puerto Rico's dams — 26 of the 38 — date to before 1960. Six were built a century ago.
"The infrastructure in Puerto Rico is decades old," said Miguel Soto-Class, president of the Center for a New Economy, a San Juan think tank. "That goes for water infrastructure, as well."
Soto-Class said that some of the island's reservoirs need dredging and therefore don't have enough water during droughts. That would also reduce the volume of water that could be held back in a heavy rain.
The long-deferred investments make it more difficult to revamp infrastructure a bit at a time, Soto-Class said. When the water and sewer authority recently updated pipes, older pipes blew up because they couldn't handle the additional pressure.
Another major dam owner is the Puerto Rico Aqueduct and Sewer Authority. Its Carraizo, Carite and Rio Blanco dams for hydroelectric power and water supply haven't been inspected since 2013, according to the National Inventory of Dams.
The Guajataca Dam is just one example of the fragile infrastructure that has collapsed — along with Puerto Rico's entire electrical transmission grid — raising the question of whether the island can and should be rebuilt to a higher standard than it has had.
But that can't be done by the dam owners. PREPA has about $9 billion in debt and the Puerto Rico Aqueduct and Sewer Authority has about $4.6 billion in debt, far more than they can service without any major new project.
"We've been cutting corners for a long time in a lot of places," Soto-Class said.