Vienna Danube regulation







The Vienna Danube regulation (Wiener Donauregulierung) refers to extensive flood-control engineering along the Danube river in Vienna, Austria during the last 150 years. The first major dams or levees were built during 1870-75. Another major project was constructed during 1972-88, which created the New Danube and Danube Island (Donauinsel). Prior to regulation, the Danube in Vienna had been an 8-kilometre (5 mi) wide wetlands, as a patchwork of numerous streams meandering through the area (see maps).

History
In Vienna, the Danube river up until 1870, was almost totally unregulated. The river flowed through wetlands on the left (east) bank of today's Danube course. Villages like Jedlesee, Floridsdorf and Stadlau that were near the former main branch of the Danube were particularly susceptible to flooding.

After repeated severe flooding, in 1810 Hofbau-Direktor Josef von Schemerl proposed regulating the river by creating a new river bed, but his plans were not realized.

From 1870 to 1875 the Danube was regulated for the first time. On the left bank, a 450 m wide flood-prone area, the Inundationsgebiet, was created with the dam Hubertusallee covering today's municipal districts of Floridsdorf and Donaustadt. The new main branch, including shipping, was 280 m wide, leaving the old river bed as the Old Danube. Additional major floods in the years 1897, 1899 and 1954, especially concerning the right bank of the Danube at Handelskai ("Trade pier"), proved that this 1875 regulation of the Danube was insufficient.

In 1972, after several years of study, a new flood-control project was started. Working up to 1988, within the inundation area, a new, 210 m wide channel (Entlastungsgerinne) was created. The material excavated from the channel was placed between the Danube and the channel, creating the Danube Island. This channel, the New Danube, is protected by fortifications and is only used to divert flood waters. It is designed for a flow of 5 e3m3/s. Overall, the Danube regulation is designed for a capacity of up to 14 e3m3/s, which is the estimated maximum flow of a flooding which took place in 1501. The Danube Island and the New Danube now serve as a popular recreation area.

Flood years and levels
Major floods in Vienna were: