The rapid erosion of alpine valleys can be prevented by torrential barriers. For their design is crucial the thrust acting upon them due to earth and water pressures. From the evaluation of damage events and field investigations it can be inferred that often no water saturation and thus not the full hydrostatic pressure acts upon such barriers. The uncertainty associated herewith is reflected in various guidelines. The field observations can be explained by the structure of the backfill but also by the distribution of the water pressure. An empirical assessment of the loads on such structures is here proposed, which takes into account the probabilities of the individual events.

Keywords: natural hazards, torrential barriers, water pressure, culverts.