Comparative eutrophication development in two Brazilian water supply reservoirs with respect to nutrient concentrations and bacteria growth

The comparison of eutrophication development in two Brazilian water supply reservoirs has shown the convenience of adopting different management strategies according to climatic conditions and to the balance between nutrient concentrations. These techniques should be directed to the prevention of cyanobacteria input in the water supply system (case of Vargem das Flores) and to the selection of the most appropriate treatment techniques (case of Gavião). Moreover, it has been shown that the dominance of cyanobacteria is not always coupled with low N/P values, as usually assumed in the technical literature.