Artificial Beach Nourishment on Norderney, A Case Study

Abstract

Norderney is one of the East Frisian Barrier Islands that extend along the western part of the German North Sea coastline (Fig. 1). Severe dune erosion jeopardized the health resort settlement on the west end of Norderney and necessitated the construction of solid coastal protection structures since 1857. These structures were successful in stopping the migration of the inlet and in preventing further dune erosion; but they were not able to maintain stable beaches. To protect the existing structures against damage artificial beach restoration was initiated on Norderney in 1951. Since then five further beach fills were necessary to affect an active protection by shifting the zone of wave attack seawards. The scouring from the groyne fields had been monitored. Based on these data the sane budget has been investigated. It has been proved, that on Norderney beach nourishment is an appropriate solution to protect the existing structures from failure during severe storm-floods. If we want to lower the amount of losses, we have to nourish the beach not higher than necessary to achieve the protection goals. Above a 'critical beach profile' in certain areas losses of nourished material increase considerably with height. Especially for the Norderney-case we should develop a 'low-cost-technique' for a 'low-rate-beach-nourishment'.