Siltation of Australian reservoirs: some observations and dam safety implications

The Australian continent can experience extreme sedimentation rates which affect water supply systems. The study documents complete reservoir siltation events. Sedimentation problems were observed predominantly with small to medium size reservoirs (catchment area less than 100 km2). The effects of reservoir siltation are analysed in terms of dam safety. In several cases, the sediment load associated with major flood events would create high loads on the dam wall, especially in the cases of thin concrete structures. For such situations, the tested concrete strength could be less than twice the load, and the safety of the dam becomes questionable.