Tyrol's drinking water: A hidden heritage from the mountains

Tyrol's drinking water: A hidden heritage from the mountains

In Tyrol, the importance of the mountains for drinking water supplies is unmistakable: around 90 percent of the state's drinking water comes from mountains, while only 10 percent is obtained from groundwater via wells. According to landscape ecologist Ulrike Tappeiner from the University of Innsbruck, the amount of water is sufficient to supply around two million people, although Tyrol only uses 30 of its 55 large springs for drinking water.

A central element of this infrastructure is the drinking water tunnel in Halltal, which is located in the Innsbruck-Land district. This was built after a severe storm in 1992, when a mudslide destroyed the previous water intakes and the communities of Hall and Absam had to rely on tankers to supply Innsbruck with drinking water. The tunnel, which was built between 1995 and 2001, protects the water from mudslides and avalanches and makes optimal use of the geological conditions of the Bettelwurf massif. Here, about 700 meters inside the mountain, a protective layer of rock begins that prevents water from escaping into the valley.

The memory of the source

According to Tappeiner, around a quarter of the precipitation that falls on the mountain surface penetrates the rock. This process takes about ten years, during which the water is purified and enriched with minerals before being collected in the tunnel. Therefore, the impact of heavy rainfall events is not immediately apparent on water availability; In this context one also speaks of the “memory of the source”. However, since the tunnel was put into operation, a decline in water supply of 20 to 30 percent has been noted. Nevertheless, there are positive signs that the discharge volume has been increasing again since 2021, even if the exact cause has not yet been determined, according to Alfred Ropic, head of the water/heat department at Hall AG.

The two experts are optimistic about the climate crisis. Ropic and Tappeiner currently see no critical impact on Tyrol's water balance, even if temperatures increase. Tappeiner explains that precipitation amounts will remain stable or even increase slightly. She highlights that despite a theoretical decrease in water availability with a temperature increase of four degrees Celsius, the amount of water still remains sufficient.

Responsibility for the downstream areas

However, ensuring responsible water use is of great importance. Tappeiner emphasizes that the countries from which large rivers originate must also bear responsibility for the areas downstream. As an example, she mentions the water shortage that occurred a few years ago in the Italian regions of Trentino and Veneto, where South Tyrol was asked to release more water from its reservoirs. This happened even though this water was not needed for energy production.

Tappeiner points out that any water that is used or polluted is no longer available in the downstream areas. In addition, large cities, including those in the lowlands of Germany and Europe, must ensure their drinking water supply from rivers and treat the water accordingly. In doing so, it underlines the urgency of sustainable water management and emphasizes the importance of the mountains for the water supply in Tyrol and beyond.

These fascinating aspects of water supply in Tyrol are essential not only for the region itself, but also for the surrounding areas, because they testify to the close connection between the natural environment and the need for forward-looking planning in water management. A more detailed analysis of the background to this situation can be found in a report on tirol.orf.at.