Yacyretá

Building the Future

By Oscar Thomas

Photo courtesy of Oscar Thomas. 


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A hydroelectric plant is about much more than water and energy. It is about community and environment, urban planning and resource development. It is about the future and the past of the surrounding area.

In 1973 the governments of Argentina and Paraguay signed the Treaty of Yacyretá to build one of the world’s most important hydroelectric power plants on the Paraná River, the fastest-flowing large river in South America.

The option for a hydroelectric plant was clear: oil, used as a fossil fuel, had to be replaced by a renewable source. 

As I am myself an architect from the province of Misiones, in Argentina, I was determined to take advantage of the development of the hydroelectric plant to transform, in a positive way, the situation of those who would be affected and to improve the urban planning for the region’s most important cities and the surrounding area.

The actual construction of the power plant took 34 years, from 1978 to 2011. Finally inaugurated in 1998 with a reservoir level seven meters (7.65 yards) lower than originally designed, the plant was producing only 60% of anticipated energy. A number of engineers and architects focused on achieving the maximum production of electric energy. At the same time, they had to ensure the adaptation of the inhabitants affected by the new reservoir level. All this took place in the Argentine provinces of Misiones and Corrientes and in the Paraguayan departments of Itapuá and Misiones. The reservoir area would encompass 1,500 square kilometers (nearly 590 square miles).

Yacyretá had already built an important bridge linking both countries over the Paraná River. However, the transformation of the surrounding region was still pending. The nearby cities had experienced accelerated growth without any urban planning. Some 700,000 inhabitants—especially the 80,000 who lived in the coastal regions under unsanitary conditions and recurrent floods— would have to be taken into account with the flooding of the reservoir. The environment would undergo changes that would alter its equilibrium.

I felt compelled to come up with possible solutions. Perhaps, being from Misiones, I was especially sensitive to the importance of the rivers—their historical, as well as environmental, importance. During the 17th and 18th centuries, the Jesuits and the Guarani-speaking indigenous peoples built more than thirty urban settlements supported by the rational exploitation of water, land and cattle-raising. The streams provided the water they needed for their own consumption and served for fishing, boating and as an energy resource for water wheels and hydraulic mills. I thought that history was not only memory but also a fund of experiences that could serve us now and in the future.

We had to come up with solutions for the high energy requirements of both Paraguay and my country. Completing the reservoir would provide it. The adequate functioning of the Yacyretá undertaking would be the guarantee for the necessary investments for the region.

My home province is a land of rivers and streams, the red soil and the jungle. No element from that habitat could be damaged. Maintaining the quality of the water would be one of our most important objectives.

Some 1,500 square kilometers were set aside as ecological reserves to compensate for the land flooded by the dam for the Yacyretá hydroelectric plant. Actions centering upon the aquatic environment involved monitoring with an eye towards conservation, as well as building capacity for local and regional governments to do the same. We can now contemplate environmental sustainability in the context of a new balance, with images of a neotropic cormorant (Phalacrocorax brasilianus) feeding on the common armado fish (Pretodoras granulosus) and several other Paraná tiger fish found in the vicinity of the dam. Nature has returned. Storks and tuyuyú birds known as American wood storks (Mycteria americana) grace the landscape of the Iberá estuary. All the actions carried out for environmental preservation are carefully explained to all the region's communities. 

The past of this region was always present as an element of identity. At the Ayolas museum, we displayed the archeological pieces found during the earlier explorations for the development of the hydroelectric plant. The Guarani and Kaingang indigenous groups had left traces of their ways of living and teachings to connect us with nature.

But my concern was not only the past; it was the future. The cities in the region had to be renewed. In Paraguay, Ayolas, Santos Cosme and Damián, San Juan del Paraná, Carmen del Paraná, Cambyretá and Encarnación were about to experience changes. In Argentina, the cities of Ituzaingó, Posadas, Garupá and Candelaria would form part of the project. Each would undergo urban reform plans jointly agreed upon with local governments that would integrate the different sectors of the city. Various enclaves were separated not only by streams but by the absence of the necessary road infrastructure. By constructing bridges and providing roads, we would transform vehicle circulation and the means of transport.

There were other challenges to ensuring future growth. Renovation and improvements had to be provided to hospitals, schools, public administration, security and services; likewise, recreational areas, parks and squares and riverside promenades had to be developed.

Thus, a new connection could be formed with the landscape and, especially with the Paraná River. The result would be the formation of urban coastal areas with access to the water for all. 

The city would be thought of as a whole, a living, growing organism.

The population affected by the Yacyretá undertaking received social and health assistance programs. People were moved to housing developments, harmoniously integrated into the city that offered infrastructure and community services. Members of indigenous communities were provided with property titles to well-constructed homes, as well as bilingual schools and social services.

All the cities in the project expanded towards the river. Encarnación has become a river resort; Posadas has considerably increased its number of tourists. The urban and rural sectors now have a better access to the cities after the construction of roads and bridges across streams.

Looking back over the changes that have taken place over a decade, I believe that the Yacyretá hydroelectric undertaking has had strong regional impact. The best way of making the most of its construction and energy production was to see the project as a way to improve the living conditions of all the people in the region by providing the vital infrastructure. That infrastructure would have been impossible to achieve without the hydroelectric sector.  

For future hydroelectric undertakings in the region, we will have to bear in mind the past experiences. Only if we integrate the necessary projects to improve the daily lives of the residents will we find support for the construction of these new works. And only with these new projects will we find adequate renewal energy for the area and beyond. 

Oscar Thomas, who hails from the Province of Misiones, Argentina, is an architect and executive director at Yacyretá of the Binational Entity of Yacyretá for Argentina. He is the Argentine President for the Argentine-Brazilian Joint Technical Committee for the Construction of the Hydroelectric Plants in Garabí and Panambí. He has taught at the Faculty of Architecture and Urban Planning of the UNNE of Argentina and at the Faculty of Architecture of the Catholic University of Paraguay.