Let's start with a riddle: Which is the oldest natural island still in existence on the heavily regulated, straightened, and de-insulated section of the Danube in Vienna? If there is one at all.
Of course there is; otherwise, the question would be pointless to begin with, and there would be no reason to even write this post. In any case, this is by no means obvious on the ground; in fact, given its morphology, it should rank among the youngest islands, and everything points to the fact that this riverbed was created by humans between 1972 and 1988, when the Danube regulation carried out between 1870 –1875 was revised in Vienna, creating the bleakest urban zone in the river’s history, known as the Überschwimmungsgebiet, where the natural riverbeds of the time lay on the banks for a long time, like dead fish after the cyanide pollution of the Tisza river. A hundred years later, these remains were dredged up and buried beneath a 21-kilometer-long artificial island called the Donauinsel, which has one positive aspect: it was ultimately not built up with office buildings and apartments, but instead developed into a city park, featuring varied topography and a diverse shoreline despite its straight, paved banks.
Along the Donauinsel, bays, peninsulas, and quieter stretches of water bordered by rock embankments have been created—and even separate Danube islands—to replace the natural tributaries that have been eliminated and so to increase biodiversity. One such artificially created island is the Albern Gravel Bank (Alberner Schotterbank), which could easily be called an island due to the floodplain forest that has developed on it, interrupted at only one point by the highly spectacular pipeline system connecting the Schwechat oil refinery with the Lobau oil terminal.
On Monday, May 11, 2026, in the early afternoon, during a low-water period of 150 centimeters—with the water level slightly receding—measured at Wildungsmauern, a significant overflow was observed in the approximately 20-meter-wide side channel next to the Alberner Schotterbank. The water flowed extremely rapidly in the deep channel between the extremely steep, eroded bank walls composed of massive pebbles. On both sides, tree roots hang in the air. There are two human-made reasons for this: one is the Freudenau Dam, downstream of which lies the Alberner Schotterbank; the other reason can be traced back to the same project, albeit somewhat indirectly. This is because beneath dams, the riverbed suddenly deepens, the original water level drops, and the islands are left dry.
That’s what happened here as well; this gravel bar is very close to the dam, and it functioned as a gravel bar right up until the dam was built. As a result of the drop in water level downstream, it became an island, which is why the forest was able to grow there, and why the side channel began to dry up. In Austria, they typically don’t leave things like this alone and set about dredging. Between 2023 and 2024, with a brief interruption when the Boris flood deposited an astonishing amount of silty sediment and debris in the area, they dredged out the deep channel still visible today, despite protests from regular beachgoers [1]. The dredged gravel was used to counteract the deepening of the main channel and was spread out below the Freudenau dam. Some online maps still show the old situation of the river, so many visitors may be surprised to find that the island can no longer be reached on foot even at low water, a fact that beachgoers have resented ever since; conversely, the wildlife is quite grateful for the isolation.
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| The Alberner Schotterbank in 1856. |
The Alberner Schotterbank first appears on Pasetti’s 1856 nautical chart of the Danube. It was closer to Mannswörth than to Albern, and was located on the opposite bank. At that time, Albern was a small fishing village belonging to Kaiser Ebersdorf, which suffered greatly from the Danube’s floods. It was destroyed by the “Himmelfahrtsgieß” flood of 1501, and then by the “Allerheiligengieß” flood of 1787, when erosion by the Danube washed away 85 hectares of land, including the village itself [2]. It was then that the fishermen relocated to the site of the present-day settlement. In 1809, Napoleon, passing through here, dismantled the village to build a pontoon bridge using the beams from the houses in Albern.
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| The Alberner Schotterbank in 1938. |
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| The upsilted island before the dredging, 2023. |
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| The current situation |
On Pasetti’s map, it appears that one of the islands in the vast Danube side channel—which was dammed off between 1836 and 1841 opposite the settlements of Albern and Mannswörth—was split in two by the dam, with the smaller, shoal-covered section remaining in the floodplain. We are most likely witnessing the very moment of the Alberner Schotterbank’s birth; in other words, this island in the Danube—now part of Vienna—will soon be blowing out two hundred candles on its birthday cake. The Albern gravel bar is a true relic. It is not so much its formation as its survival that is considered a miracle. Although it is inseparable from the history and territory of the Donauinsel today, it is very distinct from it.
Recommended and cited literature:
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