Bathing water

Official swimming water locations

We work with the laboratory Stichting Waterproef to ensure that the 31 official swimming locations in our waters are sampled monthly for bathing water parameters. These include blue-green algae, which can be toxic, and various bacteria, including E-coli. In addition, transparency, temperature, pH and the like are measured. All these things affect bathing water quality. 

The official swimming locations can be identified by large blue signs at the outdoor swimming area and can also be found on the website www.zwemwater.nl. Here records are kept of what has been measured and the results of the measurements. There are also reports on the swimming location (if you click on the location, you will see a tab on the right with measurement data and at the bottom a reference to the so-called swimming water profile). 

The province is the authority when it comes to swimming water. The province evaluates the results of measurements and determines whether a swimming location is safe enough or not. And it is the province that designates a location as a "designated swimming location. If somewhere regularly has a lot of people swimming then, if the water quality is sufficient, that location should be designated as a 'designated swimming location' (and investment should be made in management measures, such as delineating the swimming zone with a ball line). This takes into account other functions of the water, such as navigation.

If blue-green algae or bacteria exceed certain values, we advise the province about instituting a warning or negative swimming advice. We check with the province and the manager of the swimming water (the recreation board or the municipality) whether we can do something about it. Sometimes this can be done quite simply, but sometimes this has already been tried and does not work or not well enough. Of course costs play a role in this. If it's going to cost millions and only a few people go swimming then it doesn't outweigh that. Sometimes it does work and the costs are manageable. And there is no guarantee that we will never have problems again, because in nature not everything can be determined.

Other swimming water locations

Incidentally, the fact that the Netherlands has some 770 designated swimming locations does not mean that everyone who wants to swim outdoors does so at a designated swimming location. Many people swim in rivers, lakes and ponds, which are not designated for that purpose and where no explicit safety measures have been taken. Basically, swimming outside official swimming locations is at your own risk. It is not always wise, but usually not prohibited (except at bridges and overpasses). We do not sample these locations for swimming water quality. We only make an exception for swimming events, such as City Swims.

Detailed information can be found in the report "Swimming in surface water" (June 2020). This report by the Reddingsbrigade Nederland explains how swimming in surface water is dealt with. In particular, the report focuses on swimming safety and how that is regulated in the Netherlands. The project is part of the larger program NL Zwemveilig, which is coordinated by the National Swimming Safety Council and financially supported by the Ministry of Health, Welfare and Sport. The report focuses mainly on preventing drowning and less on preventing disease from reduced water quality.