In 1937, the Marion County Lake was completed by the Civilian Conservation Corps south-east of Marion. It was to be used for recreation. There were many floods during the early history of Marion. In June and July 1951, due to heavy rains, rivers and streams flooded many cities in Kansas, including Marion. Many reservoirs and levees were built in Kansas because of the Great Flood of 1951. From 1964 to 1968, the Marion Reservoir was built north-west of Marion. Downstream from the Marion Reservoir, levees were built in the low areas of Marion and Florence.