FAQ

The FOEN publishes hydrological data on rivers and lakes of varying quality ("release status"):

  • Raw data: Unverified raw data. This data may contain errors.
  • Verified data: These data have undergone an initial check and have been corrected if necessary. Changes may still be made to the data series at a later date.
  • Validated data: These data have been more thoroughly checked and corrected if necessary. There are generally no further changes to these data series.

More information on data quality

Real-time data (graphs of current data, text message service, 'Meine Pegel' app): Raw data

Forecasts: Measured raw data and data based on hydrological forecast models.

Annual tables: Verified data or validated data. Tables based on verified data are labelled ‘Provisional data’. For groundwater stations, only validated data is published in the tables.

Flood statistics and low-flow statistics: validated data.

Current data: Raw data

Monthly data delivery subscription: provisional or validated data.

Individual data delivery of historical data to clients: Raw data, verified data and validated data. The data quality (release status) is indicated on each line of data in the CSV file.

More information on obtaining data:

Current data: The latest measured values (last measured value and graphs) are transmitted directly from FOEN hydrometric stations. This is raw data which is not checked before publication (see above). Raw data and forecast values are published in local time, i.e. summer time UTC+2 (CET), winter time UTC+1 (CET).

Historical data: Historical data can be obtained from the FOEN. For historical data, the values are given in winter time, i.e. UTC+1 (CET). In exported data files, the time stamp is always indicated at the beginning of the measurement interval.

Water level data is normally collected continuously at the gauging stations. On site, the data logger calculates average values to compensate for fluctuations (e.g. through wave impact). Measurement data is therefore normally recorded in the form of 10- or 5-minute averages (rarely 2-minute averages) at stations on rivers and lakes, or 5-minute instantaneous values at groundwater stations.

Heights in metres above sea level correspond to the Swiss national levelling network LN02.

swisstopo: Swiss National Levelling Network LN02

Data can be used freely; we recommend citing the source.

Suggestion for source citation:

  • Surface waters data: Hydrology Division, Federal Office for the Environment FOEN (reference date).
  • Groundwater data: NAQUA National Groundwater Monitoring, Hydrology Division, Federal Office for the Environment FOEN (reference date).

More information:

Terms and conditions for the supply and use of FOEN hydrological data 2020 (PDF)