After widespread flooding in the United States during the early 1930s,
Congress passed the
Flood Control Act of 1938. The
United States Army Corps of Engineers built the 100-foot-high earthen dam primarily as a
flood control project for the
Mississippi River. Construction started in 1949, was delayed by the
Korean War, and was completed in 1958. The lake has a capacity of of water, equal to 137.18 billion gallons at its "100 year flood" level of .
Floods Water first flowed over the emergency spillway on July 5, 1993 (
see Great Flood of 1993), reaching a then-record crest. when water again flowed over the emergency spillway on June 12, 2008, and the reservoir crested at early in the morning on June 15, 2008. Lake Macbride is formed by another dam just up from the Coralville reservoir. This dam was overtopped by floodwaters in the flood of 2008, and the lake effectively became part of Coralville Lake. ==Recreation and public use==