| OCR Text |
Show WATER Lower Colorado Region By 1980, projections indicate a water deficiency of about 1.51 million acre-feet, increasing to more than 4.5 million acre-feet by 2020. Previ- ous studies have indicated that the Colorado River flows would need to be augmented to fulfill present commitments of 3.1 million acre-feet to the Lower Colorado Region, 4.4 million acre-feet to California, and 1.5 million acre-feet to the Hepublic of Mexico. Estimated 1965 and projected regional water withdrawal and depletion requirements are presented in Figures 11 and 12. It should be noted that quantities shown are estimated water requirements and not quantities actually withdrawn in 1965. Water withdrawals for all uses are expected to increase to a level of 12.96 million acre-feet by 2020. Projected increases are associated primarily with the needs resulting from popula- tion growth in the Region. Municipal and industrial water withdrawal requirements are expected to increase by 2.3 million acre-feet; for elec- tric power generation, 0.425 million acre-feet; for mineral development, 0.252 million acre-feet; and for recreation, fish and wildlife, 0.4 mil- lion acre-feet. Irrigation withdrawal requirements would remain about the same level as for 1965. Water saved by increasing management effi- ciencies and lining of canals would satisfy increased requirements result- ing from additional irrigation developments. The most critical immediate need is to meet withdrawal requirements projected, to occur prior to 1980 without increasing the ground-water overdraft. To gradually eliminate the ground-water overdraft, the long- range program, 1981 to 2020, would need to provide for increased annual water withdrawals of about 4.5 million acre-feet from new sources. The present and projected water withdrawal and depletion requirements for the Lower Colorado Region are summarized in Table 5. Lower Main Stem Subregion One of the most vital needs of the Lower Main Stem Subregion is the municipal and industrial water for a rapidly growing population in the Las Vegas, Nevada area. Addi-tional irrigation development is expected to occur within the Jtort Moha^ve and Colorado River Indian Reservations and other areas which woold utilize Colorado River water under existing water rights. It is estimated that the water withdrawal requirement of 3.0 million acre-feet in 1965 will increase to 3.4 million acre-feet by 1980 and then increase to 3.8 million acre-feet by 2020. 68 |
