 Flooding damages on the Mississippi – Missouri river system were one of the primary reasons for which Congress passed the Flood Control Act of 1944 , opening the way for the USACE to develop the Missouri on a massive scale . The 1944 act authorized the Pick – Sloan Missouri Basin Program ( Pick – Sloan Plan ) , which was a composite of two widely varying proposals . The Pick plan , with an emphasis on flood control and hydroelectric power , called for the construction of large storage dams along the main stem of the Missouri . The Sloan plan , which stressed the development of local irrigation , included provisions for roughly 85 smaller dams on tributaries . 
