The floods of October 9-11, 1954 in the Chicago area of Illinois and Indiana were the greatest in the history of the region. The 24-hour rainfall of 5.63 inches on October 9-10 and the 48-hour total rainfall of 6.72 inches were the greatest recorded at the Chicago Weather Bureau station in 69 and 84 years respectively. Unofficial measurements in the southern suburbs of the city indicate that nearly 11 inches of rain fell in 48 hours.
These intense rainfalls on the flat areas of the Little Calumet, Kankakee, and Chicago Rivers caused the streams to overflow their banks flooding heavily industrialized and densely populated parts of the city. Slow drainage of flood waters in large areas along these rivers resulted in a prolonged period of inundation. On the Kankakee River at Shelby, Ind., the crest of the flood occurred 17 days after the rain.
The flow of South Branch Chicago River has been diverted by locks into the Des Plaines River since 1900. The elevation at the mouth of the South Branch is held usually about 3 feet below lake level. During the flood the river rose about 3.4 feet above lake level. To relieve flooding, the lock gates were opened allowing the river to discharge into the lake for the first time in 54 years.
Notable rates of discharge occurred in the Des Plaines River basin, where Long Run had a unit discharge of 152 cfs per square mile from a drainage area of 20.8 square miles, and Flag Creek had 80.2 cfs per square mile from a drainage area of 16. 2 square miles.
Flood damages in Chicago and its suburbs have been estimated by the U. S. Weather
Bureau to be about $25 million.
Included herein, for the Chicago area in Illinois and Indiana are general descriptions of the floods, an isohyetal map showing the amounts and areal distribution of the storm rainfall, detailed stage and discharge data at 49 gaging stations, peak discharges at 4 miscellaneous sites, and water-surface elevations at 1 lake site. Floodcrest stages collected by other agencies are also presented.
Additional publication details
USGS Numbered Series
Floods of October 1954 in the Chicago area, Illinois and Indiana