As a result of storms but also gradually by the continuous action of currents and waves beaches can suffer from erosion. By in situ monitoring and mathematical modeling one develops understanding of the driving forces of this erosion. With this knowledge alternative strategies for the maintenance of the beaches can be evaluated. As a result of the climate evolution and particularly sea level rise the risk of beach erosion increases. Sustainable solutions do not work against the natural forces but use these processes such as the stability of larger grains of sand, the fixation by vegetation such as marram grass, dune formation, the long shore transport in the surf zone, equilibrium profiles.