The catchment area of the water abstraction must be adequately protected against pollution. To this end, special protection zones are established in which activities such as construction and agriculture are prohibited or restricted. If the water is not of sufficiently good quality despite protection zones, the water must be purified. There are three protection zones to protect drinking water from pollution

The protection zone III (further protection zone) is intended to protect against biochemical impurities that are difficult or impossible to degrade. The area of the protected zone corresponds approximately to the catchment area of the groundwater abstraction.

In protection zone II (narrower protection zone), permanent protection against microbial contamination (bacteria, viruses) should be ensured. This protection is achieved by a minimum residence time of the water in the soil of 60 days.

The protection zone I (collection zone) protects the drinking water abstraction as well as the immediate surroundings from damage and contamination. This zone is usually fenced in and laid out as a green area.