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Show Nonbeneficial consumption occurs as evaporation from the Great Salt Lake ( 5.0%), evaporation from fresh water lakes and streams ( 1.5%), and evaporation and use by phreatophytes and unmanaged wetlands ( 3.1%). An estimated 7.7 million acre- feet of water ( or 13 percent of the total precipitation) enters the three major basins and constitutes the manageable water supply. The Utah portion of the Great Basin yields approximately 4.5 million acre- feet annually; the Utah portion of the Colorado River Basin, 3.1 million acre- feet; and the Utah portion of the Columbia Basin, only 0.05 million acre- feet. i0 During the past few years, different agencies have conducted studies to further identify the existing manageable water supply, define present water use, and estimate projected future water requirements within the Great Basin area. These include the following, in descending order of magnitude of area covered by each study: ( 1) a Great Basin interagency study covering portions of Nevada and Utah and small portions of Idaho and Wyoming, ( 2) a Utah State water plan, y which covers the state of Utah, and ( 3) the Bonneville Unit plan^ 3 of the Central Utah Project, which covers all or portions of 12 Utah counties located in the heart of Utah. Table A- l gives data comparing related areas covered by the three studies identified above. The State Water Plan19 projects an annual increase in diversion requirement of 2.8 million acre- feet and an annual increase in consumptive use of 1.2 million acre- feet, by the year 2020. If the growth of Utah is not to be curtailed, these needs must be met. Since augmentation from outside the region is not expected before the year 2020, existing Utah water supplies must suffice during the interim. The report indicates that Utah will exert sustained effort in three major directions to cope with the water needs of the future, These are ( 1) continued efforts toward more effective use of locally available water supplies by better regulation and distribution, better utilization of groundwater basins, water salvage, and planned reuse of water; ( 2) developing the concept and the necessary physical works of an integrated water system for the state, to permit the redistribution of water from areas of relative sufficiency to areas of relative scarcity; and ( 3) improving the state's institutional and management structure so as to permit and encourage more effective use of the limited water resources. The State Water Plan1" states that the potential use for water far exceeds the water supply and priorities for use will eventually need to be established. At the present time, however, sizeable quantities of water are not being fully utilized because of a lack of reservoir capacity to store and regulate and a lack of conveyance facilities to transport the water supply to points of use. 5 |