Water supervision includes measures to avert dangers to the general public, individuals or water bodies caused by the condition or use of water bodies, banks, dykes, flood, water protection and medicinal spring protection areas as well as installations on water bodies or in these areas.

Citizens who become aware of a situation that is suspected of posing a threat to water bodies can report it to the lower water authority. The lower water authority will check whether measures are required to avert danger and arrange for these to be taken as part of its supervision of water bodies.