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Senator HAYDEN. We thank you for your statement.

Any questions, Senator Kuchel?

Senator KUCHEL. No, sir.

Senator HAYDEN. The next witness is Mr. W. S. Gookin, Arizona State water engineer, on the subject of Arizona's need for the project. Mr. Gookin.

STATEMENT OF WILLIAM S. GOOKIN, STATE WATER ENGINEER. STATE OF ARIZONA

Mr. GOOKIN. My name is William S. Gookin, and I am the State water engineer for the State of Arizona. I appreciate this opportunity to appear before you and to describe the water supply conditions as they exist in central Arizona today.

My knowledge of Arizona's water problems dates from 1937 when I, as an engineer with U.S. Geological Survey, first started measuring streamflows in Arizona. My knowledge of the central Arizona project dates from 1940 when, as an engineer with the Bureau of Reclamation, I started work on a survey of the aqueduct from Lake Havasu to Granite Reef Dam. With the exception of one 3-year period, when I was absent from the State of Arizona on other assignments with the Bureau of Reclamation, I have been continuously associated with water problems of the State of Arizona.

Arizona has for many years had serious water problems due to water shortage but today faces a crisis as a result of these problems. It is basic that in a desert country such as Arizona, the limitation on the economic development of the area is water supply. That limitation has been reached and far surpassed. We exist today only by virtue of the fact that we are mining our water resources. Such overutilization cannot continue indefinitely.

The water supply of the central Arizona project service area is not derived from a single source or utilized in a unified area. There are within the central Arizona project service area various areas of utilization which are more or less separated from each other and which are supplied from sources which are in some cases common to two or more. Any technical hydrological study must evaluate the various basins separately, but once such an evaluation has been made, it is appropriate to consider the hydrology on a broad base. This is particularly true in the central Arizona project service area where the same problems of overuse are applicable in all areas with variations being merely a matter of degree.

Surface waters within the central Arizona project service area come chiefly from the Salt, Verde, Gila, Agua, Frià, and San Pedro Rivers. Existing storage reservoirs on the Salt and Verde Rivers control essentially all of the flows of those streams. The last time any appreciable amount of water spilled from these reserviors was 1941.

The San Carlos Reservoir behind Coolidge Dam provides complete control of the Gila River upstream from its location, although some additional regulation of summer storm runoff on the upper Gila above the dam and its tributaries would be beneficial from the standpoint of flood control and water salvage.

No regulating reservoirs exist on the Gila River downstream from Coolidge Dam or the San Pedro and some water from high intensity thunderstorms on this unregulated watershed above the Buttes Dam site escapes the project area and is largely lost to evaporation and vegetation.

The flow of the Agua Fria is controlled by the Carl Pleasant Dam. The existing storage reservoirs of which I speak, combined with the diversion dams operated in conjunction therewith, serve to permit virtually complete utilization of the surface water supply, of the central Arizona project service area. Even so, this surface water supplies less than one-quarter of the total amount of water used each year in the service area.

The major portion of the central Arizona project service area is characterized by comparatively small mountain ranges separated by basins filled with various alluvial materials. These basins form underground reservoirs in which water has accumulated for geological ages. To obtain the remainder of the water supply needed to even support the existing economy of the area, the people of the State of Arizona have tapped these underground reservoirs and are pumping approximately 211⁄2 times as much water as annually enters those basins. The result of this overdraft is obvious. The static water level in our underground reservoirs is progressively lowering at a precipitous rate and the pumping levels are declining at an even greater rate.

Mr. Lassen, our State land commissioner, has demonstrated how the water levels in these ground water reservoirs is declining. Where ground water levels are declining at rates such as Mr. Lassen has demonstrated one of three results is inevitable. Either the ground water reservoir is pumped dry, the quality of the water deteriorates until it is no longer usable or the pumping lift becomes so great that the cost of pumping renders continued utilization impractical and uneconomic. In either event, continuing declining water tables eventually put the water user out of business.

In Arizona this crisis is not 50 or 100 years in the future, it is upon us today.

Approximately 1,162,000 acres of land in the project service area have been fully developed for irrigated farming. During the 195560 period an average of 880,000 acres were irrigated. The 282,000 acres made ready for irrigation, but not irrigated during this period are for the most part acres which were idle because of insufficient water supplies or because water costs increased to a point where further farming was uneconomic. Thus even though we are now mining our ground water reservoirs at a rate which can only lead to catastrophe, we still are not meeting the full requirements of our developed acreage. More than one-quarter million acres of good, developed farmland stands idle each year for lack of water. This idle acreage is increasing every year. To the individuals who own this acreage this idleness often represents economic ruin.

In any hydrologic discussion involving quantities of water it is important to clearly define the point and period of measurement. In the discussion which follows, unless specifically designated otherwise, all figures are annual averages for the 1955-60 period, at the farmer's

headgate and the intakes to the systems used to supply municipal and industrial requirements.

To supply 880,000 acres it is necessary to deliver 4,190,000 acre-feet of water annually. In addition, 300,000 acre-feet was needed to supply the municipal and industrial requirements.

Thus, even with 250,000 acres out of production, the water requirements during the 1955-60 period totaled 4,490,000 acre-feet. Since the mean long-term surface supply available to the central Arizona project service area is only 1,020,000 acre-feet annually, it is evident that the ground water basins must make up an annual deficit amounting to 3,470,000 acre-feet to sustain agricultural, municipal, and industrial development at the 1955-60 level. The gross amount of ground water which can be withdrawn year after year on a sustained yield basis is estimated to be 1,280,000 acre-feet. Thus, with sustained agricultural and static urban area such as existed during the 1955-60 period, the overdraft on the ground water basins in the central Arizona project service area amounts to 2,190,000 acre-feet annually.

Were present conditions to continue, ultimately deliveries would have to be decreased by 2,190,000 acre-feet annually.

To illustrate the relationship of these figures, chart No. 1, a copy of which is attached to this statement and entitled "Present Water Requirements Deficiency and Supply" has been prepared. The total annual water deliveries have been depicted as a circle and the relative portion which may be considered as dependable supply shown as a blue segment. The red segment of the circle entitled "Average Annual Deficiency" illustrates the proportion of present water supplies which are obtained through ground water mining and which cannot be considered to be available on a long-term sustained basis unless additional sources such as waters under the central Arizona project are made available.

I would interject that because of the difficulties of reproducing a chart in color, the chart which I have attached has been stippled and carries the same proportions.

The diversion of 1,200,000 acre-feet of water from the Colorado River, under the central Arizona project would result, after deducting conveyance losses, in the delivery of 1,020,000 acre-feet to the project direct service area. This supplemental supply would directly reduce the draft on the ground water basins and, in addition would, through deep percolation, augment the recharge to those basins increasing the safe annual yield. Effluent flows resulting from additional municipal and industrial uses could also be recaptured, thereby adding further to the total usable water.

It is anticipated that operation of Colorado River diversion facilities would be coordinated with the operation of existing irrigation works and with other conservation facilities to be developed within the project service area. It is estimated that these latter facilities, which would furnish additional storage on the Gila River and tributaries, would make an additional 50,000 acre-feet of water available for project use. Such facilities would also make possible the exchange of Colorado River water for local stream water at downstream locations, making possible the supplementing of supplies at upstream locations not susceptible of benefits by direct diversions from the mainstream of the Colorado River.

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