On 11 August 1979, the Machhu-2 earth dam, situated about 6 km upstream of the town of Morvi in the Saurashtra region of India, collapsed under the onrush of an unprecedented volume of water. An 8–10 m high flood wave rolled down Machhu valley, entirely submerging Morvi and nearby villages. This flash flood caused the deaths of thousands of people and totally destroyed urban and rural property downstream of the dam. The heavy rainfall of August 1979 over and around the Machhu basin has been analysed by both depth-area-duration and depth-duration methods. Important aspects of heavy rainfall distribution such as: analysis of past severe rainstorms, maximum point rainfall of different return periods, and probable maximum precipitation, were also studied. This study has shown that this event was not the most severe rainstorm in this region. Possibly, the antecedent conditions of the Machhu basin played a significant role in generating the flood volume which caused the earth flanks of the dam to give way.