2017-02-212017-02-212011-12-13http://hdl.handle.net/123456730/311In Brazil, human activities such as dumping of sewage, deforestation of riparian vegetation and inappropriate use of pesticides, have caused damage to the environment and water quality of rivers, especially when these rivers cut the large urban centers. The launch of fresh domestic sewage and industrial effluents are among the activities that negatively impact these water bodies. When they are not treated it degrades the quality of river water, and this have a great impact on the activities of coastal communities. The aim of the research was to analyze and diagnose the state of pollution of the River Catu in Bahia and propose measures to improve the quality of the water. The survey consisted of a questionnaire that raised the use of the riverside communities of Rio Catu, a survey that pointed sewage spills from industrial and residential projects, through the use of GPS, and analysis of water quality in four sections of the river in two periods, in May and in October 2010. Analyses were performed in the laboratories of SENAI and Laboratory Studies in Environment - LEMA of UCSAL, as well as of the results obtained through the Water Quality Index (IQA) that are a simple way to indicate the quality of water systems. This paper proposes the implementation of the weighting of IQAS as a methodology to assess water quality. It is concluded that the release of sewage and industrial effluents cause negative impacts to water quality of Rio Catu, having an impact on the flora and fauna of the river and coastal communities that need the river for some activity.Acesso AbertoÁgua superficialSurface waterIQAAnalise físico-químicoDegradação do Rio CatuPhysico-chemical analysisDegradation of the Rio CatuDissertaçãoPlanejamento Urbano e RegionalPlanejamento Ambiental