The environmental protection area of Lageado was created in 2001 in Campo Grande, Mato Grosso do Sul's State capital, and it constitutes a conservation unit that belongs to the Sustainable Use Group. The environmental protection area of Lageado is located in an urban area and provides approximately 12% of the water supplied to the municipality. Knowing the relationship between soil occupancy and population density, which may cause harmful effects to the quality of surface water and water resources, is fundamental. The present study aims to analyse the physical-chemical parameters of water samples collected at three different times and in six distinct points in Lageado. To verify whether the transformation of this watershed into a conservation unit resulted in the maintenance of water quality, the statistical analyses considered the significance and correlation among the following parameters: water quality index (WQI); dissolved aluminium, iron and copper; Escherichia coli; nitrate; ammoniacal nitrogen; Kjeldahl nitrogen; chemical oxygen demand; and chlorophyll α. The results show that the formal creation of the environmental protection area of Lageado did not provide the effective improvement or maintenance of its environmental conditions. Statistically, there were decreases in the WQI over the studied period, which demonstrates that the creation of a conservation unit is, in itself, not sufficient and it lacks the implementation of effective programmes and actions related to the soil use, occupancy and water quality.
Keywords: Cerrado Biome; Conservation unit; Environmental protection area; Sustainable management; Water quality index.