Flood of July 5-7, 1978, on the South Fork Zumbro River at Rochester, Minnesota

The intense thunderstorm of July 5-6, 1978, caused record flooding on the South Fork Zumbro River at Rochester, Minnesota. The peak discharge on July 6 was 30,500 cubic feet per second compared with 19,600 cubic feet per second for the flood of March 1965, which was the largest previously known. The 1965 flood had a recurrence interval of about 30 years, whereas the 1978 flood had a recurrence interval exceeding 100 years. The flood waters claimed at least 5 lives and 5,000 people were forced to leave their homes. Millions of dollars in flood damage was reported, and this report summarizes some of the flood data and a photomosaic map shows the inundated area.