How Protecting Kauaʻi’s Forests Safeguards Fresh Water

A new study led by the University of Hawaiʻi Economic Research Organization (UHERO) finds that conserving Kauaʻi’s native forests offers major water benefits, with each dollar invested in protection efforts generating an average of 593 gallons of groundwater recharge. These efforts focus on keeping invasive species like feral pigs and deer out of vital watershed areas to maintain the island’s freshwater supply.

UHERO — an applied research group housed within UH Mānoa’s College of Social Sciences — conducted the study in partnership with the Institute for Sustainability and Resilience, the Water Resources Research Center, and The Nature Conservancy. Their analysis showed that regions with natural barriers, such as Wainiha and Nāmolokama, yielded even higher returns, while mid-elevation areas were identified as offering the greatest recharge benefits per dollar invested.

The study also emphasized the broader ecological and climate resilience benefits of conservation, including enhanced biodiversity and erosion control. With the potential to increase total groundwater recharge from 21.4 to 34.4 billion gallons over 50 years, the findings provide a compelling economic and environmental case for expanding forest protection as part of long-term watershed management across Kauaʻi and beyond.