Evaluation of the temporal evolution of the water quality of the Mãe d'Água Dam

The Mãe d'Água Dam, located on the UFRGS campus, was built for landscape and research purposes, but over time suffered from pollution by solid waste, domestic effluents, and sediments, as well as eutrophication. This study aimed to evaluate the temporal evolution of dam water quality, comparing data with the parameters of CONAMA Resolutions nº 357/2005 and CONSEMA nº 355/2017, by calculating the Water Quality Index (WQI). Between December 2023 and April 2024, monitoring was performed at four distinct points of the dam, measuring parameters such as pH, turbidity, and dissolved oxygen, using a multiparameter probe. The results showed that points P1 and P4 had WQI indicating regular water quality, while points P2 and P3 exhibited poor quality. The P3 point presented high turbidity, suggesting contamination by sediment and organic matter, while the P2 point had low concentration of dissolved oxygen, possibly due to the presence of untreated effluents. These results highlight the degradation of water quality in specific areas of the dam, raising concerns about environmental impacts on the ecosystem and adjacent communities. The research reinforces the need for continuous monitoring and mitigation actions to preserve the environmental health of the dam and its surroundings.