Swiss perspectives in 10 languages

Water supply assured despite shrinking glaciers

Dammed lakes are set to play an ever more important role Keystone

Although Switzerland’s glaciers are retreating, water supplies will remain abundant in the coming decades, according to computer modeling performed by institutes belonging to the country’s two Federal Institutes of Technology (ETH).

Switzerland holds around six per cent of all fresh water reserves in Europe, and plays a vital role both in water supply and the production of hydroelectricity. Its 200 or so dammed lakes supply 30 per cent of the country’s own requirements for electric power and also help regulate the flow of water and prevent flooding.

Computer simulations up to the year 2099 carried out by researchers from the Swiss Federal Institute for Forest, Snow and Landscape Research, part of the so-called ETH Domain, found that overall, Switzerland will continue to have an excess of water, although stocks will decline.

However,  there will be a shift in the way water is stored.

“As a result of climate change, the role of the glaciers as water reservoirs and summer water sources will decrease,” said institute director Konrad Steffen in a statement issued by the ETH Board.

In the future, dammed lakes will have to take over part of the role currently played by glaciers, he explained.

He added that while the total amount of water run-off will remain more or less constant, there will be regional and seasonal differences.

Regionally, slightly more water will flow from the high mountains and significantly less in the southern canton of Ticino. Seasonally, peak outflows will occur earlier in the year, since higher temperatures will cause the snow cover to melt sooner.

Power supply

Hydroelectric power is slated to take on a greater role in the Swiss government’s Energy Strategy 2050, which is designed to meet the country’s electricity needs after the phasing out of nuclear power.

At present only five per cent of annual precipitation, or about one billion cubic metres, is used for the water supply, boding well for the future of hydroelectricity.

But Anton Schleiss, director of the Laboratory of Hydraulic Constructions at the Federal Institute of Technology Lausanne warned in the same statement it was important to expand the storage volume of reservoirs if a secure and independent power supply is to be achieved.

Minor increases in the height of existing dams could increase winter production – the most critical time of year – by more than ten per cent, he said.

He called for increases in the size of reservoirs, improvements in turbine and pump capacity, and the creation of new equalising basins and turbine water systems so as to enable Switzerland to function as a “battery” and bolster its position as a supplier of energy to the rest of Europe.

In March, the Swiss parliament committed funds to help strengthen energy research. The Federal Institutes of Technology will receive an additional CHF60 million ($64 million) over four years. The money will be used to create new research teams (CHF20 million) and for investments in infrastructure (CHF40 million), the ETH Board’s statement announced.

In compliance with the JTI standards

More: SWI certified by the Journalism Trust Initiative

You can find an overview of ongoing debates with our journalists here. Please join us!

If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at

SWI - a branch of Swiss Broadcasting Corporation SRG SSR

SWI - a branch of Swiss Broadcasting Corporation SRG SSR