Sustainable use of low flow reaches downstream energy generation dams

The paper describes the issues of water quality in low flow reaches downstream energy generation dams. These reaches should maintain a minimum water flow in order to guarantee adequate ecological conditions in the water body. A case study is presented with respect to the longest low flow reach in Brazil, focusing mainly on environmental and regulatory aspects. Water quality in this reach should be enhanced by the construction of some intermediate dikes, which will allow the sedimentation of particulate matter and the formation of small reservoirs for the growth of aquatic species. A concern remains only with phosphorus concentrations, since the environment will change from a lotic to a lentic condition.