Trial of fog and rainwater harvesting to alleviate water scarcity in the agricultural highlands of the Galapagos Islands

ABSTRACT The Galapagos Islands face complex challenges to protect their endemic biodiversity against anthropogenic decline while simultaneously improving the welfare and livelihoods of a growing resident community. For instance, alternative mechanisms for water provision across the impoverished agricultural highlands of Santa Cruz are being urgently sought. This study presents the results of the largest-ever trial of fog and rainwater harvesting technologies across the archipelago, focusing on their potential role in contributing to a regional sustainable water supply. The water yields from 16 installations (eight fog harvesting and eight rainwater harvesting) were continuously monitored for a period of ten months. The results demonstrated the influence of rainfall on the yields from both technologies, though fog harvesting volumes were less adversely impacted by drier months. While rainwater harvesting provides larger and more consistent yields, fog harvesting offers a viable alternative, particularly in remote locations or where rainwater harvesting is impractical. Although practical considerations such as storage availability and economic burden are critical, this study demonstrates the substantial role that off-grid water supply mechanisms can play in enhancing the resilience of Galapagos’ agricultural zones.