The Itaipu Dam on Paraná
The threats from dams and navigation on the La Plata are intense. For example, on the Paraná River, the Itaipu Dam, the largest in the world, flooded approximately 100,000 ha of land, and destroyed significant aquatic habitat including the Guaíra Falls.
Second greatest number of planned dams in the world
The basin faces the 2nd greatest number of planned dams in the world: 27 large dams, of which 6 are under construction. In Brazil alone, total generating power from hydroelectric stations is poised to reach a total of 107,307 MW in the next few decades.
In particular, new impoundments and water diversions threaten the Paraguay River’s relatively pristine headwaters, which comprise the central artery of the Pantanal wetlands, and Uruguay River.
The hidrovia project, the largest development proposed to date, both in size and scale of possible impacts on the economy and environment
The Brazilian, Bolivian and Paraguayan governments' plan for the massive navigation and hydroelectric dam project, 'hidrovia', is proceeding without an adequate Environment Impact Assessment. The hidrovia would dredge and redirect the Paraguay and Paraná Rivers to create a 3,442 Km long navigation channel at least 3 meters (~10 feet) deep between Caceres, Brazil and the harbour of Nueva Palmira in Uruguay.
This would provide cargo ships with access to the interior of Argentina, Bolivia, Brazil, Paraguay and Uruguay during the dry season.
Impact on biodiversity
The hidrovia threatens to drain and destroy habitat in the Pantanal by increasing the drainage capacity of the river outlet, affect native fish populations, and expose the river system to invasion by exotic species through links to rivers in the Amazon basin. This would seriously exacerbate the impacts from loss of water inflow due to climate change.
According to experts, lowering the level of the Paraguay River by only 25 cm on average would increase the frequency of downstream flooding and increase erosion during the rainy season, while also reducing the total flooded area of the Pantanal during the dry season by 22%.
Impact on local indigenous communities
In addition, the hidrovia would directly affect local indigenous communities whose livelihoods depend on the fish and biological resources of the Pantanal, particularly in Brazil's Mato Grosso State and in riverine communities in Paraguay.
The hidrovia is intended to facilitate expansion of the export of soybean, timber, iron ore and other commodities during the dry season at the expense of the opportunity for ecotourism, and local use of resources. It would also increase access and facilitate further dam development in the area.