Puerto Rico is experiencing a historic drought that’s led to water rationing following the driest month on record in July.
Yet one ready-made solution is barely being tapped: the normally copious rainfall. Anywhere from 30 to 169 inches of precipitation falls on the territory annually, but the government doesn't require US citizens in Puerto Rico to install catchment systems to take advantage of the free resource—unlike some other island states. As climate change increases the odds of more intense droughts on the island, that type of decentralized infrastructure may be just what Puerto Ricans need in an emergency.
“One of the best unused reservoirs of water in Puerto Rico are the roofs of the houses,” says Fernando Abruña, a partner at local firm Abruña & Musgrave Architects.
The drought has exacerbated a water crisis that was already in motion due to ruptured water pipes and other decrepit infrastructure. For the past week, Puerto Rico governor Jenniffer González has ordered municipal governments to shut off water two days at a time for people in the northeast to conserve local supplies, leaving 180,000 households with limited access. The problems began well before that, though: Many families have been without consistent water for more than 100 days.
While the drought is a factor, the biggest issue isn’t a lack of water, says environmental lawyer Ruth Santiago, but rather the government’s mismanagement of it.
“Even with the climate crisis and these droughts, we still have abundant water,” says Santiago, who works with the local group Comité Diálogo Ambiental (the Environmental Dialogue Committee). “We could be harvesting rainwater right now,” she says as a storm erupts mid-conversation.
The most resilient harvesting systems rely on gravity, using gutters to divert rainwater from a roof to a canister that connects to indoor pipes like a faucet or showerhead. Bigger systems can help collect water to cool power plants and other industrial uses.
Abruña, who is also a fellow with the American Institute of Architects, estimates the island could gather 30 billion gallons of water a year if just 1 million households used rainwater collection technology. The average resident uses 62 gallons a day, amounting to just over 72 billion gallons of residential water use a year.
The Puerto Rico Aqueduct and Sewer Authority loses about 60 percent of the island’s drinking water before any arrives at customers’ homes due to leaking pipes and failing infrastructure. The ongoing emergency was caused, in part, by a series of ruptures in the 72-inch Superaqueduct water pipe, a main artery that services major cities on the northern coast. Repairing and updating the island’s aging water distribution system is most urgent, Santiago says, but rainwater harvesting is a cost-effective solution that can be quickly implemented.
The practice is not widespread in Puerto Rico, where the government has prioritized centralized grids fed by freshwater, but these systems are popular in other island communities. Roughly 90 percent of homes in the US Virgin Islands have a cistern to collect rainwater, and the territory has building codes that require many new developments to include this infrastructure. (Barbados has similar codes.) In Hawaii, Honolulu County even offers a limited number of free rain barrel installations to residents.
“There is nothing that can help the Caribbean region as quickly and as reliably as rainwater harvesting,” says Farah Nibbs, an assistant professor at the University of Maryland Baltimore County’s Department of Emergency and Disaster Health Systems, noting governments should treat it “as part of the national water supply.”
She also says governments should help cover the costs to avoid putting onerous “economic and financial burdens on households.” Yet in Puerto Rico, the government offers no incentives or financial assistance. That’s left small organizations attempting to meet demand.
Since 2010, local environmental nonprofit Plenitud Puerto Rico has donated and installed 73 rainwater harvesting systems for neighbors in Las Marías, a mountainous municipality on the western side of Puerto Rico. Executive codirector Owen Ingley estimates that the technology costs the group $500 to $2,000 for small, simple units and up to $5,000 for larger, more advanced ones with electric pumps. There are also additional costs to maintain the system, especially if a bad storm damages it, and to monitor water quality.
The team recently installed a unit for a man in his eighties who lives alone and regularly experiences disruptions to his water supply. The system doesn’t provide drinking water, but it helps him meet other household needs such as flushing the toilet or filling his dog’s water bowl. “He’s a really sweet and talkative guy with gray hair and a big smile,” Ingley says.
José Pérez Cordero, an at-large legislator in the Puerto Rico House of Representatives, introduced a resolution in June that would order the Puerto Rican Natural Resources Committee to conduct a feasibility study on rainwater harvesting. That would include looking at how other Caribbean islands have made it work and adopting similar models for Puerto Rico. The proposal has gone nowhere, even as water insecurity mounts.
“We are, right now, in the perfect moment to do it, because we are in the middle of a crisis,” Pérez Cordero says. “Sadly, we always wait for the reaction.”
He points to a 2024 law that mandated all public agencies to implement rainwater collection systems on government buildings. That, too, has gone nowhere: Agencies aren’t following the law, nor is it being enforced. Pérez Cordero’s New Progressive Party is in power, but he says his peers have often lacked the political will to be proactive and prioritize the environment.
Rainwater harvesting won’t solve all of Puerto Rico’s water problems, particularly in urban locations where it’s hard to install them in large apartment complexes. They also aren’t sustainable if the wet season isn’t rainy enough—a prospect that’s likely to increase as burning fossil fuels heats up the planet. But that doesn’t mean they can’t play a role in shoring up a dysfunctional system.
“Facing climate change, every year is going to be harder,” Pérez Cordero says. “Every year, the dry season is going to be longer. Every year, the rainy season is going to be harder too.”
