With an annual rainfall of less than 0.04 inches, the cities in Chile’s arid Atacama Desert, known as one of the world’s driest regions, rely on ancient underground water sources for their water supply. Researchers have now discovered an additional method to combat water scarcity.
An international team of researchers has evaluated the feasibility of fog harvesting in Chile, a water-collection technique evocative of the fictional concepts from “Dune” and the moisture farming of “Star Wars.” According to a study published in the journal Frontiers in Environmental Science, this method could provide significant assistance to those living in impoverished, informal settings lacking a reliable water source.
Virginia Carter, an expert in sustainable development at Universidad Mayor and a leading co-author of the study, emphasized the potential of non-traditional water sources like fog water to enhance living standards. Carter, along with her team, conducted their research in Alto Hospicio, a rapidly expanding municipality where about 10,000 people reside in informal settlements, with only 1.6 percent having access to water distribution systems.
The team implemented basic fog collectors consisting of fine nets, or mesh, suspended by two poles. The moisture from the air condenses into droplets on the mesh, which then funnel into a gutter leading to a water tank. Although not as advanced as sci-fi suits designed to recycle urine into drinking water—a technology more aligned with space exploration—the fog collectors function passively without needing electricity or any other energy source.
Nathalie Verbrugghe, an engineer at Université libre de Bruxelles and co-author of the study, remarked that demonstrating its effectiveness in Alto Hospicio—one of Chile’s most stigmatized and swiftly urbanizing cities—sets the stage for its broader application in other urban areas facing water scarcity.
The research by Carter, Verbrugghe, and their team showed that an area of 38.61 square miles (100 square kilometers) could capture between 0.05 and 1.32 gallons (0.2 and five liters) of fog water per 10.76 square feet (one square meter) daily. August and September emerged as the prime months for fog water collection, with up to 2.64 gallons (10 liters) per 10.76 square feet (one square meter) collected each day.
Carter highlighted a shift in the perception of fog water utilization—from a rural, smaller-scale solution to a viable water resource for urban settings.
The researchers estimate that a relatively modest mesh area could harvest enough water to sustain Alto Hospicio’s green spaces. Scaling up the fog collectors could potentially meet the weekly water needs of the city’s informal settlements. Additionally, fog water could be used for soil-free farming, potentially yielding up to 44 pounds (20 kilograms) of leafy greens monthly.
The researchers acknowledge limitations in their analysis. The promising results were obtained from fog collectors positioned at higher altitudes outside city boundaries, thus requiring substantial distribution infrastructure and large storage systems for regular use. Other essential conditions include adequate fog density, favorable wind patterns, and elevated landforms. Since fog is seasonal in various regions, this variability should also be considered, according to Verbrugghe. Carter emphasized that fog can complement urban water supplies but should not be viewed as a comprehensive solution to water scarcity.
Nonetheless, the team aspires to inspire policymakers to integrate this renewable resource into national water strategies, Carter concluded, noting the potential to bolster urban resilience against climate change and rapid urbanization while improving access to clean water.
While fog harvesting alone cannot resolve the issue of water scarcity, it represents an innovative and sustainable method of water collection that might one day become a critical component of water management in desert communities.
