The construction of two dams in the Lower Volta River, Ghana, adversely affected downstream riverine ecosystems and communities. In contrast, Ghana has enjoyed vast economic benefits from the dams. Herein lies the challenge; there exists a trade-off between water for river ecosystems and water for anthropogenic water demands such hydropower. In this study, we quantify these trade-offs and show that there is room for providing environmental flows under current and future climatic conditions.