In the 1940s, a need for increased water storage capacity and additional flood control became apparent. The United States Congress passed the Rivers and Harbors Act of 1945, which called for additional construction in the Trinity River basin. The United States Army Corps of Engineers built the Garza-Little Elm Dam between 1948 and 1954 at cost of $23.4 million. The structure combined Lake Dallas, Hickory Creek, and Little Elm Creek. The long Lewisville Dam was completed in 1955, and the Garza Dam was breached in 1957 to create the new lake, known then as Garza-Little Elm Reservoir and renamed Lewisville Lake. This new lake had one hundred eighty-three miles of shoreline and a capacity. In 1998, additional modifications raised the lake's permanent level from 515 feet MSL to 522 feet MSL and increased the holding capacity to 555,000 acre-feet.