What is water protection at home

In which cases should you check?

Despite the changes to the Waste Water Self-Monitoring Ordinance, which came into force on August 13, 2020, there are still certain inspection obligations for homeowners.

For new buildings and major changes / after renovation

Anyone building a new house or making a significant change, such as installing additional connections to the existing drainage system, must have the condition and functionality of their sewers checked by a recognized expert immediately after completion. The same applies after rehabilitation of the sewer pipe. In addition, leak tests remain an important criterion for the acceptance of the sewer pipes under the contract for work, because this is the only way to ensure that the work has been carried out properly.

Well-founded suspicion of damage

What is new is the obligation to test private sewers in water protection areas for cases in which there is a reasonable suspicion on the part of a property owner that the domestic sewer is leaking. This is the case if one of the following circumstances was found during the inspection of the municipal sewer network:

  • Leaching of sand and earth
  • Rinsing of broken glass
  • Rinsing of other foreign matter, which suggests a leak in the sewer
  • Deposits of such material at the inlet area of ​​the domestic connection sewer into the communal sewer
  • in the case of subsidence in the property area or in the sidewalk area above the course of the domestic connection sewer, which suggests that sand and earth have been washed out
  • several blockages of the canal in a short time


In addition, property owners outside of water protection areas are fundamentally obliged in the suspected cases mentioned to take any necessary measures to put their pipes in order. They can be asked to do this by the community. Because of the municipality's obligation to dispose of wastewater, it is obliged to take in all the wastewater in its municipality. This gives rise to the so-called institutional power of the municipality, which entitles it to order necessary measures if damage is suspected. In justified suspicions, the municipalities can therefore also request the property owners to check their sewer pipes outside of the water protection areas.

Parish statutes

In addition, the cities or municipalities have the option of having their own statutes to require the inspection of sewage pipes in the urban area or only in certain areas and to set inspection deadlines. This can be done, for example, in so-called foreign water focus areas or if the city checks the public pipes in certain areas and wants to have the private pipes checked at the same time. Citizens will then be informed separately about this.

Old sewer pipes in the water protection area

If private sewers were built before 1965 and the property is located in a water protection area, the test should have been carried out by December 31, 2015. This is still valid. The lower water protection authority and in certain cases also the municipal drainage company can therefore continue to demand proof of the test for these sewer pipes.

The waste water consumer hotline gives you free information about whether your property is in a water protection area or not. Alternatively, you can get this information in the online database "ELWAS-WEB" of the state of North Rhine-Westphalia. This database contains all designated water protection areas in NRW. Here you will find step-by-step instructions on how to use it.