Puerto Rico is rationing water, despite receiving up to 169 inches of annual rainfall. The government could be tapping into this abundant resource, especially as climate change intensifies droughts.

Fernando Abruña from local firm Abruña & Musgrave Architects suggests that ‘one of the best unused reservoirs of water in Puerto Rico are the roofs of the houses.’ Rainwater harvesting systems, which rely on gravity to collect rainwater from rooftops into canisters for indoor use, could drastically reduce pressure on existing infrastructure. The island’s 1 million households, if all equipped with such technology, could gather 30 billion gallons annually.

However, despite the potential benefits and a recent legislative push, rainwater harvesting remains underutilized in Puerto Rico. Only 90% of homes in the US Virgin Islands have cisterns for collecting rainwater. Legislative efforts to mandate such systems on government buildings have failed to materialize, highlighting a lack of political will.

Environmental lawyer Ruth Santiago notes that mismanagement is the biggest issue, not water scarcity itself. She argues that rainwater harvesting could be a cost-effective and quick solution, yet the current infrastructure loss due to leaking pipes remains significant. The Puerto Rico Aqueduct and Sewer Authority loses about 60% of drinking water before it reaches customers’ homes.

Local environmental nonprofit Plenitud Puerto Rico has installed 73 rainwater harvesting systems in Las Marías since 2010, helping residents manage their household needs during water disruptions. Yet scaling this solution across the island remains a challenge, especially for urban areas where large apartment complexes make installation difficult.