Disruptions in the drinking water network are rare, but can occur. Rescue and emergency services cannot help all companies, facilities or citizens at the same time in the event of a large-scale crisis. It is therefore advisable to take your own precautions. You can find out how to prepare for an evacuation or other crisis situations on the Emergency preparedness page.

Wiesbaden is supplied with drinking water from various sources, including the Hessian Ried, the Wiesbaden Taunus tunnels and the Schierstein waterworks.

The water from the waterworks' wells and the Taunus tunnels is processed into drinking water in five waterworks. Together with the water from the Hessian Ried and Niedernhausen, it is pumped into various water tanks and from there enters the supply network. Mixing of the water can occur in the network.

The drinking water network consists of 26 water tanks, around 740 kilometers of supply pipes and over 34,000 house connections. It is divided into 24 pressure zones. Some zones are not physically connected to other zones. This is particularly the case in the eastern suburbs such as Naurod. Nevertheless, the area supplied by the water supply companies of the state capital of Wiesbaden (WLW) is legally considered to be one supply area.

The districts of Amöneburg, Kastel and Kostheim are not supplied by WLW, but by Mainzer Netze GmbH. They are a separate water supply area.

In Wiesbaden, four companies are primarily responsible for the drinking water supply: Wasserversorgungsbetriebe der Landeshauptstadt Wiesbaden (WLW (opens in a new tab) ), ESWE Versorgung (opens in a new tab), Hessenwasser (opens in a new tab) and Mainzer Netze (opens in a new tab).

WLW is a company owned by the city of Wiesbaden. They procure water and connect properties to the water network. The necessary pipes and other components of the water network belong to ESWE Versorgung. Both companies work closely together. WLW has leased pipes and other components of the water network from ESWE Versorgung. The water itself comes from Hessenwasser. The company is majority-owned by municipalities and supplies water to numerous cities, municipalities and distributors in the Rhine-Main region, including Wiesbaden.

The Mainz networks (opens in a new tab) supply the districts of Amöneburg, Kastel and Kostheim with drinking water.

In Wiesbaden, as in the whole of Germany, drinking water is subject to the strictest controls. The quality requirements are defined by laws, guidelines and regulations. To ensure that there are no undesirable substances in the drinking water, drinking water samples are regularly taken from the distribution network.

There are currently seventy sampling points in Wiesbaden's distribution network. Around 530 routine checks were carried out in 2024. The public health department determines how often samples are routinely taken at individual sampling points, for example monthly, bi-monthly, quarterly or annually.

In special situations, certain sampling points are sampled more frequently. In addition, there are regular inspections of extraction, treatment and distribution facilities such as water tanks and waterworks. In total,well over a thousand drinking water samples are taken in Wiesbadenevery year, which undergo various analytical tests.

Drinking water is generally not sterile. It is tested for a variety of microbiological, chemical and physical parameters to ensure that it is safe for human health. These include tests for faecal bacteria such as E. coli and enterococci, heavy metals such as lead and copper, as well as agricultural contaminants such as nitrate and pesticides.

As soon as a sample does not meet the requirements of the Drinking Water Ordinance(Ordinance on the Quality of Water for Human Consumption (opens in a new tab)), the necessary measures are taken immediately. However, slight deviations in the measured values do not usually pose an immediate health risk.

There is no general answer to this question. Some parameters are determined directly when samples are taken on site, for example the pH value of the water. Other parameters must be analyzed in the laboratory. Once a sample has been received by the laboratory, the analysis usually begins on the same day. Results of microbiological tests are available after 24 to 48 hours, depending on the method and parameters. Organic or inorganic tests can take several days to weeks.

A boiling requirement is a recommendation to boil drinking water once (up to around 100 degrees Celsius) and then leave it to cool for around ten minutes before using it. This kills germs. You can then use the water as usual. Alternatively, you can also use packaged drinking water from the supermarket if boiling is required.

The health department of the state capital of Wiesbaden issues a boiling order if there is a possibility that drinking water has been contaminated or a specific contamination has been detected. At the same time, the purposes for which the water must be boiled are specified.

There is no general answer to this question. The answer depends on the situation. If a boiling order is issued, you can find up-to-date information on this at wiesbaden.de/krisenfall.

As soon as a boil-off order is issued, we as a city inform the public immediately - including via press release, on wiesbaden.de/krisenfall and via social networks such as Facebook, Instagram and Whatsapp. Also look out for reports in local print and online media as well as on radio and television. Depending on the situation, information may also be provided via warning apps.

The boiling ban for the affected areas is valid until revoked by the health department of the state capital Wiesbaden. In order for it to be lifted, several drinking water samples in succession must be harmless.

As soon as the boiling ban has been lifted, we as the city will inform the public immediately - including via press release, on wiesbaden.de/krisenfall and via social networks such as Facebook, Instagram and Whatsapp. Also look out for reports in local print and online media, on the radio and on television. If warnings have been issued, an all-clear will also be given via the apps.