Starting in the 1940s, the federal government had also sought to build a high dam at the Melones site. The Flood Control Act of 1944 authorized the U.S. Army Corps of Engineers to build a flood control structure with about four times the capacity of the irrigation districts' dam. However, they were unable to provided a sound economic justification for the project on flood control alone. In the 1950s, the U.S. Bureau of Reclamation proposed a much larger dam with a capacity of 2.4 million acre feet (3.0 km3), which would capture most of the extra floodwaters that the existing small irrigation dams could not hold. It would be a multi-purpose unit of the Central Valley Project, providing irrigation, flood control, hydropower and fishery flows. Locals initially criticized the project, saying that it was too big, a waste of federal money, and the reservoir would never fill. There was also concern that the Bureau of Reclamation was attempting a "water grab" that would take the extra water to meet obligations outside the Stanislaus River Basin. However, after the Christmas flood of 1964 caused massive destruction along the Stanislaus River, New Melones gained political support. After federal funding was approved, construction started in 1966.