18.09.2026
Hydrological Yearbook of Switzerland 2025
Discharge, water level and water quality of Swiss waterbodies
The Hydrological Yearbook of Switzerland is published by the Federal Office for the Environment (FOEN) and gives an overview of the hydrological situation in Switzerland.
It shows the changes in water levels and discharge rates of lakes, rivers and groundwater and provides information on water temperatures and the physical and chemical
properties of the principal rivers in Switzerland. Most of the data is derived from FOEN surveys.