Statements (2) and (3) are the potential threats to the safety oflarge dams. A characteristic of flash floods is the localised nature of the heaviest rainfall. When the large amounts of this localisedprecipitation fall within a small drainage basin, flash floods can occur in the catchment area, thus multiplying the threat to the safety of large dams. Seismic activities in the surrounding areas can cause the failure of large dams resulting into widespread submergence ofthe nearby areas.