Dam Release for Mitigation of Impacts on Neotropical Fish Communities: The Challenges In Brazil

 Flow regulation causes various environmental impacts in the downstream reaches of impounded rivers. The environmental flows are discharges that should be released into a river system to maintain a "healthy" riverine ecosystem. They are a necessary step toward mitigating impacts. The biggest rivers of South America flows in the Brazilian territory. The impact on the Brazilian rivers has became more intense due to the necessity of water for economic growth. As consequence, the discussion about actions for mitigation of environmental impacts, such as dam releases, has increased also. The determination of environmental flow involves the analysis of hydrological data prior to and after man impacts on the river flows. The application of these actions demands studies of economic losses. However, the challenges for dam releases in main Brazilian watersheds are many, such as the lack of hydrological information, lack of knowledge about life cycle of Neotropical fish communities, the occurrence of different economic activities in same watershed and the existence of unique system of energy management in Brazil. The objective of this study was to identify possible dam releases in São Francisco River basin, which is Brazil’s third most important watershed as well the challenges for environmental flow implementation. The results show there more social and economic challenges for dams releases in the downstream areas than in upstream regions. However, there are problems related to system of energy management in entire watershed, what can create difficulties for dam releases.