Study region: The study region is the Big Bend Reach of the Rio Grande/Bravo, from Luis L. Leon reservoir in the Rio Conchos to Amistad reservoir in the Rio Grande/Bravo mainstem. This reach is part of the Rio Grande trans-boundary river basin between United States and Mexico, an area of recognized environmental and socioeconomic significance by both countries. Study focus: A central challenge of Integrated Water Resources Management is the design and implementation of policies to allocate water to both humans and the environment in a sustainable manner. This study uses the results from a water-planning model of the Big Bend Reach of the Rio Grande/Bravo to quantify and compare the economic benefits of two water management policies: business as usual (Baseline) policy and a proposed reservoir re-operation policy to provide environmental flows (EFs). New hydrological insights: This study determines the economic feasibility of the EF policy. Results show that a proposed Environmental Flow policy would increase irrigated agriculture profit, slightly decrease recreational activities profit, and reduce costs from flood damage and environmental restoration compared to the baseline policy. In addition to supporting ecological objectives, the proposed EF policy would increase the economic benefits of water management objectives.