Puerto Rico’s Drought Highlights Its Vast Untapped Rainwater Harvesting Potential
Puerto Rico is currently grappling with a historic drought that triggered widespread water rationing after July became the driest month the territory has ever recorded. Even amid this crisis, one ready-made solution remains almost entirely unused: the island’s normally abundant annual rainfall.
Puerto Rico receives between 30 and 169 inches of precipitation each year, but unlike many other island jurisdictions, the Puerto Rican government does not require resident U.S. citizens to install rain catchment systems to capture this free natural resource. As climate change increases the likelihood of more intense, frequent droughts on the island, this kind of decentralized water infrastructure could be exactly what communities need to withstand emergencies.
“One of the best unused water reservoirs in Puerto Rico are the roofs of our houses,” says Fernando Abruña, a partner at local architectural firm Abruña & Musgrave Architects.
The current drought has only exacerbated a long-brewing water crisis already driven by burst pipes and other crumbling, outdated public infrastructure. Over the past week, Governor Jenniffer González has ordered municipal governments to shut off water service for two full days at a time for northeast Puerto Rican residents to stretch limited supplies, leaving 180,000 households with severely restricted access. But the problem predates this latest emergency: thousands of families have gone without consistent running water for more than 100 days.
While drought is a contributing factor, the core problem is not a lack of water, explains environmental lawyer Ruth Santiago, but government mismanagement of the resource. “Even with the climate crisis and these droughts, we still have abundant water,” says Santiago, who works with local advocacy group Comité Diálogo Ambiental (the Environmental Dialogue Committee). “We could be harvesting rainwater right now,” she noted mid-interview, as a rainstorm erupted outside.
The most resilient rainwater harvesting systems operate on simple gravity: gutters divert runoff from a roof into a storage canister, which connects directly to indoor plumbing for uses like faucets and showers. Larger-scale systems can supply water for cooling power plants and other industrial operations. Abruña, also a fellow with the American Institute of Architects, estimates the island could collect 30 billion gallons of water every year if just 1 million households adopted rainwater collection technology. For context, the average Puerto Rican resident uses 62 gallons of water per day, adding up to just over 72 billion gallons of total annual residential water use across the territory.
The Puerto Rico Aqueduct and Sewer Authority already loses roughly 60 percent of the island’s drinking water before it ever reaches customers’ homes, due to widespread pipe leaks and failing infrastructure. The ongoing emergency was partially sparked by a series of breaks in the 72-inch Superaqueduct, the main water artery serving major cities along Puerto Rico’s northern coast. Santiago says repairing and updating the island’s aging distribution network is the most urgent long-term priority, but rainwater harvesting is a cost-effective solution that can be rolled out much faster.
The practice is not widespread in Puerto Rico, where the government has long prioritized centralized water grids fed by natural freshwater sources, but it is standard in many other island communities. Roughly 90 percent of homes in the U.S. Virgin Islands have cisterns to collect rainwater, and the territory’s building codes require most new developments to include this infrastructure. Barbados enforces similar mandatory rules. In Hawaii, Honolulu County even offers a limited number of free rain barrel installations for 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. Nibbs argues governments should treat rainwater harvesting “as part of the national water supply,” and notes public funding is needed to avoid placing onerous “economic and financial burdens on households.”
Yet in Puerto Rico, the government offers no incentives or financial assistance for residential rainwater harvesting, leaving small local organizations to fill the gap on their own. Since 2010, local environmental nonprofit Plenitud Puerto Rico has donated and installed 73 rainwater harvesting systems for residents of Las Marías, a mountainous municipality on western Puerto Rico. Executive co-director Owen Ingley estimates small, simple systems cost the group $500 to $2,000, while larger, more advanced setups with electric pumps cost up to $5,000. There are also additional ongoing costs for maintenance (especially after a storm causes damage) and regular water quality monitoring.
The team recently installed a system for an 80-year-old man who lives alone and regularly faces water service disruptions. While the system does not provide drinking water, it covers most of his other household needs, from flushing the toilet to refilling 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 expanding rainwater harvesting across the island. The study would examine how other Caribbean islands have successfully implemented the practice and adapt similar models for Puerto Rico. But even as water insecurity grows, the proposal has gone nowhere.
“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 crisis to react.”
He points to a 2024 law that mandated all public agencies install rainwater collection systems on government buildings. That measure has also been ignored: agencies are not complying with the rule, and there is no enforcement to hold them accountable. Pérez Cordero’s New Progressive Party holds power in Puerto Rico, but he says his peers have consistently lacked the political will to act proactively and prioritize water and climate resilience.
Rainwater harvesting will not solve all of Puerto Rico’s water problems. It is difficult to install large systems in dense urban apartment complexes, for example, and systems cannot sustain communities if the wet season brings far less rain than average — a risk that will only grow as fossil fuel emissions warm the planet. But that does not mean it cannot play a critical role in shoring up the island’s dysfunctional water 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.”
