Indicator water

Bathing water quality

The assessment of bathing waters is made on the basis of hygienic quality using E.coli and intestinal enterococci. They provide indications on the effectiveness of water protection measures and in particular the extent to which waste water treatment plants are fulfilling their function. Good hygienic quality of bathing water is essential to ensure that the population can bathe in rivers and lakes without any risk to health.

Assessment of the state
good good
Assessment of the trend
positive positive
Poor quality 2021: 2.3 Sufficient quality 2021: 2.3 Good quality 2021: 5.2 Excellent quality 2021: 90.2 Poor quality 2020: 1.282 Sufficient quality 2020: 1.923 Good quality 2020: 9.615 Excellent quality 2020: 87.179 Poor quality 2019: 1.156 Sufficient quality 2019: 2.89 Good quality 2019: 3.468 Excellent quality 2019: 92.486 Poor quality 2018: 1.266 Sufficient quality 2018: 1.266 Good quality 2018: 6.329 Excellent quality 2018: 91.139 Poor quality 2017: 0 Sufficient quality 2017: 4 Good quality 2017: 3.2 Excellent quality 2017: 92.8 Poor quality 2016: 1.935 Sufficient quality 2016: 1.29 Good quality 2016: 3.226 Excellent quality 2016: 93.548 Poor quality 2015: 2.609 Sufficient quality 2015: 0.87 Good quality 2015: 1.739 Excellent quality 2015: 94.783 Poor quality 2014: 2.941 Sufficient quality 2014: 1.471 Good quality 2014: 1.471 Excellent quality 2014: 94.118 Poor quality 2013: 0 Sufficient quality 2013: 0 Good quality 2013: 6.154 Excellent quality 2013: 93.846
Quality classes, as % of all evaluable bathing water according to the EEA method (hygienic evaluation)

Data for the graph: Excel
Source: Cantonal agencies


Thanks to various preventive measures and major efforts in waste water treatment over the last few decades, the bathing water quality of Swiss rivers and lakes is very good today: It is possible to bathe in lakes and rivers in Switzerland almost everywhere without any health risks.

Only after heavy rainfall or during flooding is it advisable not to bathe in rivers: bacteria adhere to suspended particles and these may be ingested by bathers if they swallow the water. In the case of rivers and streams which act as receiving water courses for waste water treatment plants, increased volumes of waste water may be introduced as a result of storm overflows and can adversely affect hygienic conditions.

In the case of bathing water of limited quality, in accordance with the Waters Protection Ordinance, the authorities must take measures such as better water protection, upgrading of wastewater treatment plants or closing direct discharges, or explicitly advising against bathing. It can therefore be assumed that there will be a positive development in the quality of bathing water in the future.

International comparison

Compared with other European countries, the quality of Swiss bathing water is very good: As is the case in only a few other countries, even major rivers and lakes in Switzerland are inviting bathing waters with outstanding quality.


Assessment of bathing water quality is carried out on the basis of cantonal water monitoring data relating to the hygienic parameters E. coli and intestinal enterococci (faecal bacteria). The EEA classification system applies to the quality assessment according to the EU Bathing Water Directive of 2006 (see table 3, section 7 of the Recommendation for the Assessment of Bathing Waters).The EEA classification can only be calculated on the basis of a series of measurements of at least four bathing seasons, with four samples per season.

Basis for assessment of the trend
Targeted trend Initial value Final value Variation in % Observed trend Assessment
Stabilisation Average 2013-2015 Average 2019-2021 -1.36% Stabilisation positive
Basis: Excellent quality, Good quality
Last updated on: 07.06.2022

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