The scheme for the Gabčíkovo-Nagymaros Dam System in Hungary and Czechoslovakia consisted of dams and canals that were to redirect and alter the Danube drastically on a stretch of about 200 kilometres, according to a bilateral agreement. They were to dry out Europe’s last inland delta, the Szigetköz, and place a dam in the Danube Bend, an iconic landscape of national identification. This prospect mobilised Hungary’s first environmental initiative, founded by biologist János Vargha in 1984. Initially, the group used Samizdat underground publications. Despite oppression during the early years, the movement kept growing, and the political climate of perestroika made large protests and petitions possible in 1988. One year later, Duna Kör reached its most significant success: the socialist government suspended the construction of the Nagymaros dam, and its democratic successors discarded the project entirely in 1991.

Even touching on the topic was seen as political suicide in Hungary for decades. It was so closely related to the events of regime change, and many politicians in post-socialist Hungary had built their careers on fighting the dam. So did Viktor Orbán and the FIDESZ movement that joined the environmental protest in 1988. However, these „Young Democrats“ have remarkably changed their agenda, so the debates were reopened in 2016. 

While not building the dam became a symbol for democratisation in Hungary, completing the scheme became a symbol for nation-building in newly independent Slovakia, aiming to achieve energy autonomy. Consequently, Slovakia continued alone in the 1990s. The Danube was redirected towards the Gabčíkovo Hydro Power Plant near Bratislava. The major share of water was provided for the Slovak power plant, while the Szigetköz on the Hungarian side of the now abandoned border river dried up.

As the following dispute could not be solved diplomatically, it was taken to the International Court of Justice in 1997 – without significant results. A bilateral conflict would have prevented the two countries from entering the European Union in 2004. Thus, the official debate was muted, and unofficial solutions were found to share the current and produce electricity while main­taining the threatened inland delta by technical means.

Since then, the Szigetköz has survived only due to the water management provided by the dams that almost destroyed it. Hydroengineers aim to simulate the most favourable water levels of the last decades, including seasonal droughts and floods, to provide the best conditions for the ecosystem.

However, it would be false to blame the dam system alone for the problems of the delta: the transformation of the Szigetköz had started centuries earlier: first in terms of land reclamation by local farmers, then dredging and diking of the Danube by Habsburg engineers accelerated the process. Long before the dam project, weirs had to be installed to prevent the side arms and oxbows from running dry. The Szigetköz became an example for the ongoing extension of the technosphere, which increasingly assimilates the biosphere.