Water supply and wastewater disposal

The Best Tap Water: A Given in Vienna

Every day, Viennese residents drink tap water and use it to cook their meals. This is entirely safe, thanks to Vienna's excellent water supply system. This is made possible by around 1,100 employees who work tirelessly on behalf of the city of Vienna to maintain, operate, and keep clean the drinking and wastewater infrastructure of this city of 2 million people. This ensures that Vienna’s water demand—approximately 400,000 cubic meters of fresh tap water per day—is met around the clock.

Spring Water from the Alps: Vienna’s Treasure

Since 1873, Vienna’s drinking water has been sourced directly from springs in the Alps and transported into the city, which is exceptional for a metropolis like Vienna. This is made possible by two high spring pipelines, 31 water reservoirs, and a network of pipes that would reach from Lisbon to Warsaw if laid end to end. All of this ensures that Vienna's population is supplied with the best high spring water 24/7. To secure the long-term water supply for Vienna's residents, the city invests continuously in the maintenance and expansion of the pipeline network and water reservoirs to ensure that the population is supplied with the best drinking water even in times of crisis.

Vienna Water Charter – Unique Protection Against Privatization

Vienna is the first city worldwide to protect its drinking water supply from potential privatization through a municipal constitutional provision. This demonstrates how important the high quality and reliable provision of drinking water is to both the population and the city. After all, drinking water is a vital resource!

Water Around the Clock – Even During Blackouts, Droughts, or Power Outages

Since the planning phase of the I. Vienna High Spring Pipeline, care was taken to ensure that the water flows into Vienna by gravity alone, without the need for pumps. In addition to the 70 springs from the Alps, the city also has 30 groundwater wells. This ensures the water supply even during heat and drought periods, on peak consumption days, or during extended maintenance work on the high spring pipelines.

Water Makes Vienna Climate-Resilient

Climate change and the resulting urban overheating pose challenges for Vienna. To mitigate heat islands, Vienna has 55 monumental fountains, 100 mist showers, and around 1,500 drinking fountains—75 of which are equipped with additional mist spray functions at particularly busy locations—to provide cooling on hot days. Sixteen water power plants in the source areas along the high spring pipelines and within the city contribute to making Vienna climate-resilient by generating electricity. These plants produce enough green water power to supply more than 40,000 people.

Modern Sewer Network Keeps Vienna Clean

With more than 2,500 kilometers of pipes, 52,000 manholes, and 124 pumping stations, Wien Kanal is Austria’s largest sewer network operator. Every day, half a billion liters of wastewater from two million people and 180,000 buildings are transported to the treatment plant in Simmering safely and environmental friendly. To keep everything flowing smoothly, sewer workers operate underground. Each year, they remove around 5,000 tons of deposits from the sewers— that's the equivalent of about 20 tons per working day. The wastewater experts are supported by a digital control system, which draws on 700 monitoring stations, 150 electromechanical and 300 static control structures, as well as 35 weather stations. On average, Vienna’s sewer network grows by 10 kilometers each year. About 1,000 sewer construction projects are carried out for maintenance. Approximately five kilometers of sewers are rehabilitated underground each year—almost entirely without excavation. Wien Kanal’s robots are also active underground. Every year, they travel roughly 200 kilometers through the wastewater labyrinth to inspect the pipes for damage.

Vienna Prevents Flooding Often Unnoticed

The climate crisis is bringing ever hotter summers and increasingly severe thunderstorms and heavy raining. As a result, floods have become a constant threat. While retention basins like those in Auhof or the Danube Island were specifically built for flood protection, the wastewater sewers were never originally designed for that purpose. Nevertheless, with the help of large underground storage facilities and modern sewer network control, Vienna is able to divert stormwater out of the city. The system’s capacity during heavy rain is boosted by regulating flows and using the underground labyrinth as a giant reservoir. Without the New Danube, the city would have suffered from floordings several times in the past two decades. Thanks to a perfectly coordinated flood protection system, the population is largely unaware that the frequent heavy rainfalls and storms could otherwise inundate Vienna—because the city is able to manage volumes of water by carefully controlling them. This is only possible because Vienna has retained responsibility for essential public services. When rainfall exceeds normal levels, a sophisticated safety network diverts water into retention basins. Only when that is no longer enough and the Danube itself is in flood does the city play its trump card—opening up the sluices to the relief channel. Flood protection in Vienna isn’t just about safety. The city also makes a conscious effort to minimize interference with nature and to preserve its high quality of life.

Europe's Most Modern Wastewater Treatment Plant in Vienna

Vienna-Simmering is home to one of Europe’s most modern wastewater treatment plants, which treats more than 500,000 cubic meters of wastewater per day and ensures that the Danube leaves Vienna with the same high water quality it had when it entered the city. Every year, two billion liters of so-called thin sludge are produced, containing the pollutants removed from Vienna’s wastewater. This thin sludge is the raw material for energy production at the city’s treatment plant, which generates significantly more eco-power than it consumes for wastewater treatment through specialized processes. Vienna's commitment to continually developing and employing more innovative and effective technologies is also why Vienna is home to Europe's most powerful large-scale heat pump, which uses already treated wastewater for energy production. The three large-scale heat pumps in use supply tens of thousands of households with green district heating and save up to 300,000 tons of greenhouse gases annually when operating at full capacity.

For further information on water supply and wastewater disposal in Vienna, please visit:

Vienna's water https://www.wien.gv.at/english/environment/watersupply/

Vienna's water supply https://www.wien.gv.at/english/environment/watersupply/supply/index.html

Vienna's sewer system https://www.wien.gv.at/english/environment/sewer-system/