On the Bratislava bank of the Danube, one of the side arms did not dry up on its own: during the construction of the Prístavný bridge, it was first covered with a concrete plant, then a burnt ship's hull was dragged there, and waste from the demolished old Petržalka was brought in. In the memories of boaters, this sounds like a story about the river, and at the same time about the city's habit of treating the Danube floodplains as empty space for decades.
For a person living in Bratislava or visiting for a weekend by the water, the consequence is simple: parts of the banks that should be cool bays, spawning grounds, and quiet places for kayaking still look like an industrial backyard. But it is here, within the city and a little downstream, that Slovakia is trying to give the Danube back its "side breath." And this is already noticeable not only to ecologists — fishermen, rowers, and residents of Petržalka also notice it.
What exactly did Bratislava lose
The modern Danube near the Slovak capital is not a "wild" river, but a heavily rebuilt channel. In 1886–1896, the riverbed began to be regulated according to the projects of the Italian engineer Enea Lanfranco. The banks were reinforced with stone, and many natural arms and floodplains were cut off or gradually filled in. In the 20th century, this was continued by bridges, embankments, industrial sites, and finally, Gabčíkovo — a reservoir launched in 1992, which drastically changed the water regime downstream.
The ecological cost turned out to be high. According to environmentalists, up to 50% of natural biotopes have been lost in the Slovak section of the Danube, and the fish population has decreased by about 70%. Therefore, the story of the arm under the Prístavný bridge is not a local curiosity, but a small episode of a big change. The river was squeezed between dams and cities, and then people wondered why it held water worse, overheated faster, and became poorer in life.
Why dead arms suddenly became important
Slovak ecologists explain revitalization very practically: to return water to the landscape. Side arms, oxbow lakes, and floodplain meadows act as a buffer. They slow down flood waves, replenish groundwater, and provide fish with quiet places to spawn. People also benefit from them — shade, moisture, and access to the river without a concrete slope under their feet.
This is especially noticeable for Žitný ostrov, a large island region between the Danube and the Little Danube below Bratislava, where the groundwater level is directly related to how much water remains in the arms and wetlands. The BROZ organization, which systematically deals with the restoration of river arms and wetlands, has restored over 34 km of such sections in recent years. Part of the money comes from European programs, including LIFE, part from the Slovakia's Recovery and Resilience Plan, and individual projects are supported by private foundations, such as The Coca-Cola Foundation.
Two examples that show the scale
In June 2026, the Malé Foki arm, part of the historic Istragov arm, was restored. Over 8,300 cubic meters of silt and sediment were removed from it, the current was restored for 343 meters, and the condition of about 20 hectares of adjacent ecosystems was improved, wrote Bratislavské noviny. The numbers are not astronomical. But it is from such several hundred-meter sections that the living network of the river is formed.
A year earlier, in 2025, BROZ completed 11 months of work on the Foki arm near Gabčíkovo: they excavated 2 km of the riverbed, removed about 80,000 cubic meters of material, and reconnected the arm to the main Danube, so that new spawning grounds would appear there, Teraz.sk reported. The difference between Malé Foki and Foki shows the approach: somewhere it is enough to clear a silted mouth, and somewhere it is necessary to actually re-lay the riverbed through decades of sediment and development.
What this means for people in Bratislava
The return of the arms does not mean that tomorrow the concrete under the Prístavný bridge will disappear and a wild beach will appear. The city is too densely built, and the Danube here remains a navigable artery with requirements for safety, ice drift, and flood protection. But the logic has changed: instead of "filling in everything unnecessary," they now calculate which old riverbeds can be reopened, where to leave water in the wetlands, and where not to interfere with the river eroding the bank.
What does this mean in practice? If you go to the Danube in Bratislava or travel downstream, pay attention not only to the embankment. Look for signs of nature conservation projects, restored channels closed to traffic, and places where water suddenly returns to its former course after rain. This is not landscaping for the sake of appearance. Each such arm slightly reduces the heat around and supports fish, and the Danube gets a chance to be not only a transport axis between Vienna and Budapest, but also a living river next to home.
