Document: "Lower Colorado River Project", 1961-1969, (carbon copy) page 55. Upper Tributaries This subunit includes problem areas within the Gila River Basin of Arizona to which direct diversion of Colorado River water cannot be made but which can increase water use through exchange arrangements with the Central Arizona Project. Proposed investigations would include studies of possibilities for development and conservation of the local water resources and the study of water exchange possibilities. Reconnaissance investigations of the Upper Gila River and San Pedro River areas are now in progress. Similar investigations of the Santa Cruz River are programed to begin next year. V. SOUTHERN NEVADA DIVISION A. Southern Nevada Water Sup...