V - Missouri Department of Natural Resources

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INTRODUCTION
Outstanding floods occurred July 18-23, 1965 on Missouri River tributaries in an area east
of the Missouri River extending [rom the lowa-Hissouri State line on the north to the Blackwater
River basin on the south and east into the Grand River basin (fig. 1). Floodwaters [rom these
tributaries produced extensive flooding on the Hissouri River from St. Joseph to its mouth near
St. Louis.
The floods were due to torrential rainfalls during July 17·20 following a 4-month period
of near normal precipitation. Storm totals amounting to more than 20 inches were reported at
Rockport and Edgerton. The Little Platte River at Smithville crested 7.4 feet higher than any
previously known flood. The crest on the Platte River, 3% miles northeast of Agency, where a
streamgaging station has been in operation since May 1924, was 4.6 feet higher than any prev­
iously recorded stage. Four lives were lost, 15 communities suffered damages and thousands of
acres of croplands were flooded.
Purpose and Scope
The purpose of this report is to document these outstanding floods for future hydrologic
planning within the State. Data related to unusual floods are essential to wise development,
within any basin, where the threat of potential flooding endangers public interests and public
safety. This report presents storm and flood descriptions, damage estimates, peak stages and
discharges, flood profiles, station data, and discharge hydrographs for the floods of July 18­
23, 1965 and indicates the unusually high recurrence interval of both rainfall and runoff assoc­
iated with this storm.
Cooperation and Acknowledgments
Rainfall data in this report were collected by the Weather Bureau precipitation gaging
network and several precipitation gages operated by the U. S. Geological Survey in connection
with streamflow network operation. The Weather Bureau and Corps of Engineers collected addition­
al rainfall information by contacting local residents in areas of intense rainfall. These data
were used by the Weather Bureau in preparing an isOhyetal map and representative mass rainfall
curves for the storm. The data are published in the July 1965 issues of Monthly Climatological
Data and Hourly Precipitation Data for Iowa, Nebraska and Missouri. Hourly precipitation data
collected by the U. S. Geological Survey at Blairstown, Osborn, and Arrow Rock, Missouri were not
published but are available from the District office in Rolla, Missouri. The sections on meteor­
ological conditions and on rainfall intensity and distribution were prepared by the Environ­
mental Science Services Administration, Weather Bureau, Kansas City, Missouri. Flood damage