The map shows the current situation of discharges and water levels of Swiss rivers and lakes. The current values are expressed in percentiles; these are calculated using all daily averages from the comparison period for the day in question. The standard period 1981–2010 is used as the comparison period. If this period is not available for a particular gauging station, the data is evaluated from the earliest measurements up to and including 2010. If less than 10 years of measurement data is available, no classification is made.

The percentile indicates the proportion of comparative values that are lower than the current value.

• For example, if the current discharge corresponds to 'very high', this means that at least 95% of all daily averages in the period 1981–2010 were lower than the current discharge. The discharge is thus significantly higher than would be expected on average for that day.
• If the current discharge corresponds to 'average', it lies between the 25th and 75th percentile. 50% of daily averages are in this range.
• If the current discharge is classified as 'low', only 5% of all daily averages in this period were even lower during the comparison period, while 75% were higher.

Further information (historical data, statistics, etc.) is available by clicking on the stations.

Basic monitoring network: water levels and discharge in surface waters – Background information on the FOEN monitoring network