Monitoramento e controle da qualidade da água em usinas hidrelétricas : estudo de caso para a Cemig Geração e Transmissão S.A.

Abstract

Cemig manages the aquatic resources associated with its projects, identify and evaluate the impacts, and monitors the main risks related to water. It also set goals for reduction of water consumption in its unities, participates in the planning, and take operative measures in its hydropower plants to improve the efficiency of water use, always considering the specificities of the drainage basins and ensuring the multiple water uses. Cemig acts towards water conservation and preservation of springs in order to guarantee water availability in the drainage basins where it has enterprises. Additionally, it has a monitoring network to investigate quality of water in its reservoirs. Beside legally established physicalchemical parameters, Cemig also records data on biological groups such as phytoplankton, zooplankton, and zoobenthos that are considered integrative communities of lentic and lotic environments according to the ecological integrity concept. Inland aquatic ecosystems present great faunal and floral diversity and the Brazilian hydrographic network highly complex and very diverse. Thus, the main objective of this study is to describe how the monitoring and water quality control are conducted in Cemig Geração e Transmissão S.A.s 86 hydroelectric reservoirs located in the States of Minas Gerais, Espírito Santo, and Santa Catarina. It also aims to create a manual for monitoring and controlling water quality in those reservoirs which will help the Núcleo de Gestão e Qualidade da Água (Managing and Water Quality Center, free translation) of the company. In order to reach those goals, it is presented a description of the water quality managing actions used by the company in its reservoirs and a presentation of the companys efforts to fight and control the opportunistic and/or invasive species found in the impoundments. Additionally, it is discussed the main environmental constraints imposed by the environmental protection agency during the operation stage of the hydropower plants for which the company has the economic concession. This work was divided into six chapters: Introduction, literature review, water resources managing in Cemig GT, results and discussion, conclusions, and final considerations