A historic storm in Central Europe brought devastating floods to many countries, including Poland, Hungary, Austria, Czechia, Hungary, and Romania. Twenty-seven were killed, and several more sustained injuries and mental health impacts. Vienna, Austria, however, experienced only mild impacts thanks to its extensive floodwater control system, one that can serve as a model for other cities around the world.
Between September 13 and 16, 2024, a low-pressure system moved into Western Europe and continued east, eventually turning into Storm Boris, bringing record-breaking levels of precipitation to much of the region. Boris dropped more than three months’ worth of rain in three days. This led to catastrophic flash flooding, especially in parts of Austria and Northern Czechia.
Unfortunately, Vienna was not entirely spared from the deluge, experiencing 10,000 cubic meters per second of water flowing through the drainage system. However, the effects of this only included 10 minor injuries and 15 evacuated houses. The ingenious flood management system, which began development in the 1970s, is being given credit for saving many lives and property.
One critical aspect of the stormwater system is that it was designed to handle 14,000 cubic meters per second of flood discharge, the equivalent of a 5,000-year storm. The 10,000 cubic meters per second experienced during Boris was easily controlled. Another important feature of the system is the artificial Danube Island and the flow channel named the New Danube. The channel and island system are controlled by weirs that allow excess water from the Danube to flow into the channel during heavy rainfall.
Austria’s substantial investment of $67 million (around €60 million) annually in flood control also includes emergency drills practicing the use of mobile walls to hold back floodwaters, as well as updating and improving forecasting systems. The investment paid off during Boris, with an emergency plan already in place and accurate rainfall totals predicted.
Vienna’s success story is being contrasted with the disastrous flooding during Hurricane Helene in the Appalachian region of the U.S., where hundreds were left dead and even more missing. Unlike Austria’s preparedness measures, the Federal Emergency Management Agency’s flood maps and subsequent infrastructure only account for 100-year and 500-year floods, or floods with a 1% and 0.2% chance of happening in any given year, respectively. Lessons can be learned from Vienna’s handling of Boris and can be used to save lives around the globe.
By Sarah Ortega