19.11.2018 | News SLF
Artificial snowmaking in ski resorts consumes a lot of water, which can become scarce during periods of drought. The SLF has surveyed resort operators to discover where they obtain the water they need and whether they recognise the existence of a clash between artificial snowmaking and drought.
From a countrywide perspective, the use of water resources for machine-made snow does not pose a direct threat – after all, the Alps are regarded as the reservoir of Europe. On the other hand, precipitation is unevenly distributed both geographically and over time, and periods of drought could become more commonplace as a consequence of climate change. In recent times, 2003, 2011, 2015, 2016 and 2018, for instance, are all recognised as examples of dry years. Against this backdrop, the problem chiefly arises in individual regions, such as inneralpine valleys where relatively small amounts of precipitation are registered. According to Pascale Josi, who is studying for a master’s degree while contributing to the work of the SLF, “Almost a quarter of the 120 surveyed ski resorts recognised the potential conflict between water resources management and artificial snowmaking.”
Reservoirs mitigate the problem
Artificial snowmaking takes place predominantly during the months in which natural watercourses are already carrying relatively small amounts of water. In order to ensure local security of supply during periods of water scarcity as well, reservoir construction activity in ski resorts has increased in recent years. Water levels are replenished by melt water in the springtime and continuously maintained throughout the year by natural inflows. Reservoirs in ski resorts provide the operators with large quantities of water for a brief period without depleting natural water resources. A third of the Swiss ski resorts that engage in artificial snowmaking, however, do not have access to such a reservoir. “In the absence of a local reservoir, artificial snowmaking during dry periods becomes more difficult,” explains Josi. Operators who wish to use surface water to produce machine-made snow must obtain a permit, which is subject to constraints. The governing factor is the minimum residual water level prescribed by federal law. Although the residual water level primarily applies to watercourses, it also has to be maintained when water is taken from a lake and the flow of the watercourse is affected.
The ski resorts surveyed for the master’s degree dissertation that is being written at the SLF were ones that use local water resources for artificial snowmaking purposes. Multiple responses to the questions were allowed. 34% of the resorts reported drawing water for machine-made snow from streams or rivers, 30% from the drinking water supply, 21% from springs, and 15% from lakes. Reservoirs were disregarded because the water they hold originates from the forenamed sources as well.
The survey was conducted in the context of a master thesis that is nearing completion on the basis of research undertaken at the SLF and the University of Bern. Its subject is water management in artificial snowmaking and thoughts on the future of snow sports in Switzerland. Ski resort operators in Switzerland were asked questions about climate change, water management and forward thinking. One hundred and twenty operators in 18 cantons were invited to comment on potential future problems or conflicts relating to water management in artificial snowmaking in their resorts.