Switzerland’s water bodies are used intensively. They supply drinking and process water, are used to produce energy, provide indispensable habitats for animals and plants, and enable people to enjoy high quality recreation. The wide-ranging requirements of society and intensive agriculture pose a challenge to the quality of Switzerland’s water bodies.
Pressure from built-up area and land use
Switzerland's watercourses are extensively engineered and limited in their natural functions. The numerous flood protection structures, energy production and reclamation of land for agriculture and development area have resulted in the structure of one quarter of all watercourses being in poor ecological shape. Around one quarter of these watercourses require rehabilitation.
Bed load budgets and fish migration are impaired. Over 100,000 artificial barriers block the upstream and downstream movements of fish in streams and rivers.
Not all watercourses are equally affected by these negative changes:
- At 52%, the highest number of watercourses with structures in an unnatural state is found in the Alpine valleys at altitudes below 600 m.
- The corresponding figure for the Central Plateau is 38% and 36 % for the Jura.
- Above the valley floors in the Alps, it is only 15% (above 600 m).
Intensive construction activity is also problematic for the groundwater as, due to the associated progressive soil sealing, precipitation flows off the surface instead of seeping and feeding into the groundwater.
Use for hydropower production
The use of water bodies for hydropower production results in insufficient residual water volumes in watercourses and impairs the natural functions of the water bodies through the strong variations between surges in the water level and low flow (hydropeaking).
The quality of Switzerland's water bodies is generally good. However, groundwater and surface water quality is reduced by residues from fertilisers and plant protection products, and by components of personal care and cleaning products and drugs. These micropollutants can have an adverse effect on water quality, even in very low concentrations.
In many medium-sized and large rivers, the majority of micropollutants come from wastewater treatment plants (WTPs). Approximately 4,800 km of Switzerland's 65,000 km-long network of waterways are polluted with wastewater from these point sources.
Last modification 30.12.2019