As Vienna’s Donauinsel (Danube Island) celebrates its 25th birthday this year, the Architekturzentrum Wien recently devoted an evening to its planning history, featuring an interesting talk by Harald Erber in which he talked about August Zottl’s (and his son Hermann Zottl’s) vision behind the island as well as alternative proposals and current development scenarios.
The story of the Donauinsel is a fascinating story of an urban planning project which probably wouldn’t be feasible today due to its complexity, its size and environmental requirements – especially not within such a short timeframe and not to mention the lack of political will and public funds as well as opposition by political parties, media and the public that would be expected today.
But first things first: The Donauinsel is not only a success story of urban planning but also an integral part of the city’s highly sophisticated flood protection system and one of the its favorite recreation areas. The 21.1 km long and 70-210 m narrow island between the Danube river and the parallel excavated New Danube channel is best known for its annual music festival with 3 million visitors and as a great place for walking, cycling, swimming, surfing, rollerblading, hanging around or having BBQs.
As Wikipedia mentions, the story of the Donauinsel ranges back to the 19th century when – between 1870 and 1875 – “a central bed, 280 m, was dug out, and an inundation area of 450 m was created at the Danube’s left bank.” After a flood severely hit the city in 1954, August Zottl developed his plan of “digging an additional channel to replace the former inundation area, and using the spoil to build up the remaining strip of land between the straightened bed from the 19th century flood defense schemes and the newly created one.”
Other approaches included the construction of higher dams which would have increased the danger of potential floods, a widening of the riverbed which would have posed problems for ships or diverting the river to the North which would have been a barrier for future urban development. So, Zottl’s plan was soon tested in a model, declared a preferred water engineering project (to speed up regulatory approval) in 1968, approved by the City council in 1969 and approved by regulators in 1970.
After thinking about how to manage the actual construction process, construction already began in 1972. As construction first solely focused on flood protection and didn’t address the island’s future use and design, the City of Vienna in 1972 launched an idea competition with a renowned international jury.
44 proposals were submitted and included ideas such as using the site for a university campus, a central train station or a building complex for international organizations. Nevertheless, the jury decided that the island should eventually be used as a recreation area for the public, with no golf clubs, tennis clubs, fences, etc. With hindsight, this was not only a great decision but also a wonderful piece of luck that tremendously contributes to Vienna’s high quality of life today.
Construction lasted until 1988 when the island was finally officially opened. As expected, people already used the area for recreation during construction, thereby highlighting the extraordinary appeal of water in urban environments. In fact, while planners in the 1970s hoped that the Donauinsel would attract up to 80,000 people a day, today between 200,000 and 300,000 people inhabit the island on a nice summer day.
Finally, from Harald Erber’s talk and the subsequent discussion, it became clear that the main reasons for the success of this huge urban development project were the simultaneous planning, legislative and construction process as well as quick political decisions, strong political backing and politicians’ attitude to let the experts do their work, in particular when it came to technical or design questions.
The flood control system is designed to protect from flash floods bringing river flows of up to 14,000 m3 per second. This has only happened once in Vienna’s history in 1501; the heavy 2002 flood and the recent June 2013 flood brought flows of 10,000 and 11,000 m3 per second. Once again, the Donauinsel served as the cornerstone in Vienna’s flood protection system, as seen in this video: