Yaciretá dam

From Freepedia

Yaciretá-Apipé (or just Yaciretá) is an hydroelectric dam located on the Paraná River between Argentina and Paraguay, 83 kilometers downstream of Posadas City, next to Praguayan city of Ayolas, and Argentine city of Ituzaingó, Corrientes Province. It was named after the Yaciretá island, now 80% covered by the waters of the reservoir, and the Apipé islands, now completely covered.

The dam is 808 metres long and has 20 turbines with a power of 4.050 MW that can produce 19.080 GW/h, with maximum water flow of 55.000 Cubic metres per second. There's a Canal lock to let the ships through the dam overcoming the 25 metres water difference, as well as a system to allow fishes go upstream, during reproductive season.

The project was heavily criticised before construction, as 1,600 square kilometres of land where to be covered by water as reservoir to the dam, what finally eliminated the natural environment of a number of species. As a result, a lot of fish died right after the dam was filled (due to the oxygen difference in the water), and fish mortality is in high levels. The reduction of inhabitable environment has decreased the number of several species of the area. Also in danger where the Esteros de Iberá in the Corrientes Province, through suspected underground infiltration. City floods during heavy rains have been also said to be caused by the higher level of he waters. Before flooding the reservoir, new houses had to be built for the relocation of 40.000 people who lived in the area.

Even though it was started at the end of 1983, it was not until 1994 that the dam started working, in middle of a corruption scandal, and after the original budget was largely exceeded. In 1998 the dam started working in full capacity, though there are plans to raise the water level 7 more metres to increase power generation, but by doing so covering 500 square kilometres more, and affecting 80.000 more people.