The Gabčíkovo power plant is a run-of-river power plant in Slovakia at river kilometer 1836 and uses the hydroelectric power of the Danube. It is the largest hydroelectric power plant in Slovakia and generates around 11% of the national electricity requirement. As early as 1947 Stalin wanted to make the shallow alluvial plain between Győr and Bratislava navigable all year round. A canal was intended to enable Soviet warships to reach the borders of what was then the Eastern Bloc. In the 1950s, the first plans were drawn up but never realised.
After major floods in the area in the 1950s and 1960s, particularly in 1954 and 1965, Hungary and Czechoslovakia signed an agreement on September 16, 1977 to build the Gabčíkovo–Nagymaros barrage system, the so-called “Budapest Agreement”. A large power plant was planned in Gabčíkovo, shortly before that an approximately 60 km² Dunakiliti-Hrušov reservoir and a second smaller one around 120 km downstream in the Hungarian city of Nagymaros (as an equalizing reservoir) on the Danube bend. This would have required 200 km of canalization or diking of the Danube. The construction costs should be borne equally by both states. Since the majority of the objects to be built were located on Czechoslovak territory, Hungary undertook to build Czechoslovak objects named in the agreement at its own expense. The electrical energy generated should also be shared equally.[1] According to the original agreement, the works were to be fully completed by 1991, with full commissioning of the Gabčíkovo power plant expected in 1989 and the Nagymaros power plant a year later. As early as 1981, the Hungarian government wanted to suspend the project for financial reasons, and in 1983 Czechoslovakia and Hungary agreed to extend the work by four years. In 1984, Hungarian environmentalists (Duna Kör) reinforced their ecological concerns about this mammoth project with a signature campaign. Concerns about drinking water and the existence of the riparian forests in particular played a major role. After the end of the Kádár government in 1988, the new government stopped all work in Hungary in May 1989 without giving a reason after a scientific study of the ecological consequences of the project, after only three months earlier it had signed a protocol to accelerate construction. By that time, 85 to 90 percent of the work on the Czechoslovak side had already been completed. On October 31, the Hungarian Parliament decided to halt work on the Nagymaros power plant and gave the government powers to negotiate an amendment to the 1977 Budapest Agreement. In 1993 both countries agreed to appeal to the International Court of Justice in The Hague. On September 25, 1997, the Court ruled that both countries had breached their legal obligations, Hungary in almost every point of the treaty. Czechoslovakia (later Slovakia) had the right to complete the construction but not to put it into operation. The original contract continues to apply and both countries should negotiate a new, more environmentally friendly solution. In its decision, the ICJ held that the agreement concluded between Hungary and Czechoslovakia was a treaty with territorial ties. For such a treaty, it follows from customary international law that a successor state must take over the treaties of the territorial predecessor. Slovakia is therefore bound by the former treaty between Czechoslovakia and Hungary. To settle the dispute, representatives of both governments agreed on a framework agreement in March 1998. To date, no real agreement has been reached, which has strained relations between Hungary and Slovakia for years.[7] In June 2017, a representative of the Slovak government sent an application to the ICJ to end the proceedings, which had been ongoing since 1998, for an additional decision. The Hungarian side stated in July 2017 that they did not oppose the Slovak request.