This report explores how traditional knowledge (TK) can support sustainable water management and climate resilience, focusing on three historic systems: Aflaj in Oman, Acequias in the Southwestern United States, and Qochas in Peru. Each system demonstrates centuries-old practices that remain relevant today for addressing environmental challenges, particularly in arid and semi-arid regions.

The Aflaj in Oman are underground channels that distribute groundwater to communities. Despite their sustainability, they now face pressures from urbanization, pollution, and declining interest among youth. Oman has enacted legal protections, including the 2017 Aflaj Protection Law, to preserve these systems as part of national heritage.

Acequias are community-managed, gravity-fed irrigation systems brought to the Americas by Spanish settlers. They continue to play a vital role in agriculture and cultural identity, but face threats from climate change, legal disputes over water access, and modern development. Local organizations and laws in New Mexico and Colorado are helping to protect them through policy and funding.

In Peru, Qochas are circular, depression-based reservoirs used for high-altitude agriculture. Once fading, these systems have been revived through the Climate Change Adaptation Program (PACC), a partnership between the Peruvian government and the Swiss Agency for Development and Cooperation. Over 190 qochas were built or restored, improving water security and livelihoods.

The report concludes that integrating traditional knowledge with modern policy and science can enhance climate adaptation, protect ecosystems, and empower local communities. Earthna calls for increased recognition of TK in policymaking, protection of intellectual property rights of knowledge holders, and community-led implementation. It also plans to expand its work by documenting other traditional practices in water, land, and food systems.