The storm was caused by a cut-off low weather system. The maximum rainfall was in the same order as that of tropical cyclone Domoina, but the flood peaks were, on the whole, less extreme. Very rare flood peaks seem to occur rather frequently, consequently there is an urgent need to develop more realistic statistical analyses.
Extreme storms and the resulting floods over Natal appear to come from two distinct weather-generating mechanisms. The paper descriptionbes the estimation of the mixed distribution functions for the two components and attempts to regionalize large storms for design purposes.
The exceptional continuous heavy rain in the catchments of the major Natal rivers flowing through Durban caused very high flood levels to occur. The magnitudes of the floods are considered, as are the means of determination of the flows.
The September 1987 floods in Natal, which caused extensive damage to property and loss of Iife In the densely populated areas, also caused extensive damage to the bulk water supply infrastructure supplying the Pietermaritzburg and Durban metropolitan areas.