Zanjeras are resource management institutions that have endured for centuries in the Ilocos region of northern Luzon. By most accounts, these cooperative irrigation societies emerged during the Spanish regime when Augustinians were deployed to congregate indigenous populations into pueblos, convert them to Christianity, and raise tributes for the Crown. Zanjeras emerged from a blending of two traditions: the Iberian model of irrigation and zanjera practices that involved water-for-land exchanges with landowners and atar-holdings to distribute shares among the members. Like other farmer-managed irrigation systems in Southeast Asia and globally, zanjeras are self-governed, long enduring, and serve as exemplary models of sustainable agriculture. They have met the test of time, but will zanjeras survive under new complexities that result from urbanization, economic modernity, and increased vulnerabilities due to global effects of climate change? The book explores these challenges and proposes actions that governmental bodies can undertake to strengthen the adaptive capacity of zanjeras and other irrigation communities around the world.