The sign marks the „old“ waterway which is dry now

At Bratislava, the Danube enters the Hungarian plain where it formerly deposited a big fan of sediments. The Danube runs on top of this gravel and sand body which is filled with one of the largest groundwater reservoirs. This so-called "inland delta” is a very dynamic network of forked and meandering arms that regularly changed its structure. Since 1880, this wild system has been tamed through various river engineering steps that improved navigability and local flood protection.

 

Dry Danube bed and side-arm system

 

Modern river engineering was initiated only in September 1977, when a joint treaty was signed between Czechoslovakia and Hungary to construct the Gabcikovo-Nagymaros river dam complex. The objectives included improving navigation and flood protection, and exploiting the river more intensively by producing peak power at the Gabcikovo Dam, with the resulting flood waves being caught up in the 130-km-long reservoir impounded by the Nagymaros Dam.
While Czechoslovakia completed most of the scheme in the 1980s, Hungary, which received support by the Austrian Donaukraftwerke (Danube Powerplant Co.), started late. In 1989, however, as a result of public protests and a change in political power, works were halted. Widespread criticism both inside Hungary and from international experts and environmental groups caused Hungary to abandon the bilateral treaty in May 1992.
Czechoslovakia, on the other hand, having already invested very much in the construction, decided in 1991 to quickly build a unilateral solution in the form of a new river diversion dam at Cunovo, only a few hundred meters upstream of the Hungarian border. While resumed negotiations encouraged by the European Commission were under way, Slovak engineers dammed the river bed in late October 1992 and started operating the power plant. Since then, over 80% of the river flow and all commercial navigation have been directed through the 25-km-long Gabcikovo side-canal.
As a result, parts of the Danube bed and the extended side-arm system fell dry. In spring 1993, artificial irrigation systems started providing water for these floodplain biotopes on both sides of the river (altogether 8,000 hectares).

Gabcikovo: one of the hottest water disputes in Europe

However, the former open and interconnected ecosystem became dissected by numerous dikes and cross-barriers into separated parts. The Danube lost its function as a "life pump” regularly moistening and draining the riparian landscape. The stabilisation of formerly very dynamic hydrological and morphological processes led to a continuous degradation, with many forest areas drying up and fisheries receding and rare pioneer habitats and species diappearing. Another major loss involved the former purification effects for the Danube waters through the filtering process in the rich vegetation and soils.

 

Are new solutions possible?

 

In March and April 1997, the legal dispute between the two states was discussed under world-wide attention at the International Court of Justice in The Hague. On 25 September 1997, the judges ruled "that both Parties committed internationally wrongful acts”: They must now negotiate a new solution jointly using the present technical variant (i.e. without Nagymaros) "in such a way as to accommodate both the economic operation of the system of electricity generation and the satisfaction of essential environmental concerns." Indeed, there are new proposals by Slovak, German and WWF experts to restore the river-floodplain system.
Since autumn 1997, both parties have conducted a number of negotiations but have so far failed to find a mutually satisfying solution. Today, Gabcikovo is a major economic burden since the cost of massive loans and of the dam maintenance cannot be covered by income generated by the hydropower plant. Therefore, October 24th was no day to celebrate, neither for the environmentalists nor for the dam operators.

 

Author: Alexander Zinke