Environmental flows in the Rio Grande - Rio Bravo basin
International audience ; The Rio Grande/Bravo is an arid river basin shared by the United States and Mexico, the fifth-longest river in NorthAmerica, and home to more than 10.4 million people. By crossing landscapes and political boundaries, the Rio Grande/Bravo bringstogether cultures, societies, ecosystems, and economies, thereby forming a complex social-ecological system. The Rio Grande/Bravosupplies water for the human activities that take place within its territory. While there have been efforts to implement environmentalflows (flows necessary to sustain riparian and aquatic ecosystems and human activities), a systematic and whole-basin analysis of theseefforts that conceptualizes the Rio Grande/Bravo as a single, complex social-ecological system is missing. Our objective is to addressthis research and policy gap and shed light on challenges, opportunities, and success stories for implementing environmental flows inthe Rio Grande/Bravo. We introduce the physical characteristics of the basin and summarize the environmental flows studies alreadydone. We also describe its water governance framework and argue it is a distributed and nested governance system across multiplepolitical jurisdictions and spatial scales. We describe the environmental flows legal framework and argue that the authority over differentaspects of environmental flows is divided across different agencies and institutions. We discuss the prioritization of agricultural usewithin the governance structure without significant provisions for environmental flows. We introduce success stories for implementingenvironmental flows that include leasing of water rights or voluntary releases for environmental flow purposes, municipal ordinancesto secure water for environmental flows, nongovernmental organizations representing the environment in decision-making processes,and acquiring water rights for environmental flows, among others initiatives. We conclude that environmental flows are possible andhave been implemented but their implementation has not ...