Ecologically, the construction of the dam most greatly affected the environment of the region in three ways. Firstly, it altered aquatic habitats via the elevation of the water level and the flooding of previously dry areas, which produced chemical changes in the water, including a drop in water oxygen levels. Besides, the alteration of the streams of water affected the dynamics of the floating vegetation that in the system Iberá is the habitat of many endemic species. The more calm water behind the dam has also allowed the spread of waterborne diseases and disease vectors, such as schistosomiasis, dengue fever and malaria.