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Show DIXIE PROJECT, UTAH 107 I should like to review briefly for you the existing uses of water in Utah's portion of the Virgin River Basin and possible effects of the proposed Dixie project on the quantity and quality of the water in the river as it leaves Utah and flows into Arizona and on into Lake Mead. Others have already or will discuss the physical and financial features of the project, the needs of the local people for this development and the benefits to the people in the project area, the region, State, and Nation. As most southwest rivers, the Virgin is an erratic and flooding stream. Much of the annual flow comes heavily laden with silt particularly that resulting from heavy summer storms. After the river breaks out of the deep eroded canyons above Hurricane, Utah, the gradient lessens and the river fans out over a wide flood plain. Canal diversions from this section of the river are practically impossible. Periodic flooding causes shifting of the river bed and supports dense stands of phreatophytes, particularly salt cedars and willows, resulting in considerable nonbeneflcial use of water. A few miles below St. George, Utah, the river again enters a canyon section and emerges just east of Littlefield, Ariz. From this point to where it discharges into Lake Mead, a distance of some 40 miles, there is an almost continuous area containing many acres of dense phreatophytes with the low flow river channel meandering back and forth through them supplying the water to keep them luxuriantly green. The heavier floods flush out sand and silt accumulations and " irrigate" the many acres of nonbeneflcial vegetation. Because of the heavy movement of silt down the river, with some being deposited at one point and some eroded from another, and with the wide variation in flow it is impractical to attempt to control the unregulated river into any single channel and to prevent waste of water. The Dixie project will provide for control of destructive and wasteful floods and for silt storage and necessary regulation and distribution of water to the land to be irrigated. The Virgin Reservoir has a capacity of 246,000 acre- feet. Seventy- three percent of this capacity will be dedicated to silt storage and flood control. Of the 24,000 acre- feet storage capacity proposed for the Lower Gunlock Dam on the Santa Clara River, 10,000 acre- feet- 42 percent of the total storage-• is to be reserved for silt storage and flood control. Combined, the two project reservoirs will stop a large part of the silt now going into Lake Mead. They will also stop much of the flooding along the entire lower reaches of the Virgin River in Utah, Arizona, and Nevada. But, most important, a large portion of that water now consumed nonbene- flcially will be available for beneficial uses of man. Before the construction of Hoover Dam only limited use could be made of the uncontrolled Colorado River waters, flood damage was high, and wastes of water were inevitable. On a smaller scale, but still far too large for individual people or communities to handle, is the control and use of the Virgin River water. Utah will benefit greatly from this project, but Arizona and Nevada both stand to gain substantially along the Virgin River from the flood and silt control provided by the Dixie project. Those who will be benefiting most directly- Irrigation and municipal users- in Utah will be paying most of the costs and this seems proper. But the benefits to others down the river through flood control, water salvage potentials, silt removal, and better regulated streamflow, should not be overlooked. There are those who oppose this development on the basis that Utah has no right to increase her uses of Virgin River water, that the Colorado River Basin is already overappropriated for existing and approved projects, that further hydrological studies are essential to good planning, et cetera. However, I believe that few new reclamation projects! will be built in the United States in the future if reasonable and sound developments can be stopped by political opposition. There are few if any unbuilt projects that will not Aral strong opposition from some source, and if the Dixie project, with its highly favorable benefit- cost ratio ( 2.3 to 1) cannot proceed, many others that are far less needed and far less economical in terms of new water development, will probably be for- |
