The hydrogeological conditions are unfavourable for a sufficient supply of drinking-water. The small size of the catchment area, the large hydraulic gradient inside the steep 'Buntsandstein'-cliff and the low geodetic level of the 'Dune Island' and the foreshore at the eastern foot of the cliff do not allow the formation and recharge of a sufficiently exploitable geodetic freshwater dome over the underlying saltwater. This means that until recently the provision of sufficient drinking-water for the island's inhabitants, for its garrison as well as for visiting ships was a problem. This problem has now been solved by the desalination of seawater.

ELEVATION [m a.s.l.] represents the sampling depth (Entnahmetiefe).

Supplement to: Johannsen, Alfred; Seifert, Alfred (1981): Trinkwassergewinnung und -versorgung auf Helgoland - von den Anfängen bis zur Gegenwart. Meyniana, 33, 41-59