Its task is easy to describe, but hard to execute. When extreme storms hit, the system must move enormous volumes of water within seconds – fast enough to keep parts of the city dry.
For Wien Kanal, operator of Vienna’s wastewater system, the project is less about theoretical capacity and more about action. Climate change has altered rainfall patterns across Central Europe. In Austria, hourly heavy rainfall has increased by around 15% over the past four decades. In August 2024, a single thunderstorm dumped more than 100 millimeters of rain over parts of Vienna in just two hours – an event once considered exceptional.
In dense urban areas, that combination leaves little margin for error. “For facilities such as the Donauinsel pumping station, this development means one thing above all: systems must no longer only be capable of moving large volumes of water, but of doing so within the shortest possible time and with maximum operational reliability,” explains Otto Max Schaefer, Division manager ANDRITZ Pumps Division. “Extreme rainfall creates unpredictable peaks that push traditional design concepts to their limits.”
