Construction of the 11 recommended participating projects would constitute a material advance in the development of the upper basin water resources. They would bring 132,360 acres of new land into agricultural production and provide supplemental water to 233,930 acres of land now irrigated with an inadequate water supply. They would also supply industrial and municipal water and hydroelectric

energy.

STORAGE UNITS

The Echo Park and Glen Canyon units of the storage project are part of the plan for regulation of the upper Colorado River through which the provisions of the Colorado River compact can be met and additional use of apportioned waters can be made in the upper basin. The basin plan would eventually comprise a system of seven large regulatory reservoirs located at strategic points of control on the main stem and major tributaries of the upper Colorado River. At each of the seven storage sites a powerplant would be constructed for the generation of hydroelectric energy. Two additional powerplants with small reregulating reservoirs that would utilize upstream regulation would complete the integrated storage and power system of the plan. The Secretary, however, recommends initial construction of only two of these power and storage units, and has selected the Echo Park and Glen Canyon units because of their economy and efficiency.

Although the regulatory reservoirs proposed in the basin plan are generally below the points of diversion for the participating projects, they would serve essentially the same purposes as reservoirs above points of diversion. This would be achieved through a replacement practice quite common on western streams where water is diverted upstream in exchange for storage water releases from downstream reservoirs. In this manner the downstream obligations would be met. It would be impossible and there is no necessity to provide this replacement through reservoirs at the sites of the participating projects. Selection of a few large reservoirs would also facilitate the integrated operation of the system, which would be necessary in order to provide river regulation, water for consumptive use and generate the optimum amount of hydroelectric power from the system's water as it is released to meet downstream obligations.

Optimum production of power at the Glen Canyon and Echo Park units would be assured by the construction of interconnecting transmission lines. These interconnecting facilities would permit maximum flexibility in power operation and facilitate the delivery of Glen Canyon power to load centers in the upper basin States. The initial lines would be the backbone of the transmission grid to which subsequently constructed powerplants would be added. Supply lines from the transmission grid would be constructed to serve local market areas. Ten major private power companies support this project and propose to absorb the project power output from a main transmission system and deliver it to existing and prospective customers. This would relieve the Federal Government of a portion of its contemplated construction cost.

Glen Canyon Dam would be on the Colorado River in northern Arizona approximately 13 miles downstream from the Utah-Arizona border and 16 miles upstream from Lee Ferry. The dam would be a concrete structure rising 700 feet from bedrock and 580 feet above the

river. The reservoir would offer final regulation for deliveries of water at Lee Ferry in compliance with the Colorado River compact. Out of a total capacity of 26 million acre-feet, 20 million acre-feet would initially be active capacity. The reservoir when filled would have a normal water surface area of 153,000 acres and would extend about 186 miles up the Colorado River, nearly to the mouth of the Green River, and 71 miles up the San Juan River. It would be the principal point of sediment control in the upper basin.

Even after 200 years, at the present rate of sediment flow and with upstream storage developed, almost half the initial storage space would be available for river regulation.

A powerplant would be located near the toe of Glen Canyon Dam It would consist of 7 generating units with a total installed capacity of about 800,000 kilowatts or approximately one-half the total capacity contemplated for the entire Colorado River storage project.

The total construction cost of the Glen Canyon unit, with an appropriate share of transmission costs, is estimated at $421 million. Also provided in the proposed bill of authorization would be the construction of facilities for adequate protection of the Rainbow Natural Bridge.

Echo Park Dam would be located in Colorado on the Green River about 3 miles east of the Utah-Colorado State line and 3 miles below the junction of the Green and the Yampa Rivers in the tri-corner area of Colorado, Wyoming and Utah. The dam would be a concrete structure rising 690 feet from bedrock and 525 feet above the river. The reservoir would have a storage capacity of 6,460,000 acre-feet, including 5,460,000 acre-feet of active capacity. When filled to capacity the reservoir would have a surface area of 43,400 acres and would extend 63 miles up the Green River and 44 miles up the Yampa River.

The powerplant at the dam would consist of 4 generating units with a total capacity of about 200,000 kilowatts.

The construction cost of the Echo Park unit is estimated at $176 million including an appropriate part of the basic transmission system but not including the Department's plan for recreational development of the Dinosaur National Monument estimated to cost $21 million.

PARTICIPATING PROJECTS

A participating project is defined as any water-consuming project which would utilize water of the upper Colorado River system for irrigation and require repayment assistance on irrigation costs from power revenues of the storage project.

The following 11 such participating projects are recommended for initial authorization in the Secretary's supplemental report: LaBarge, Wyo., Seedskadee, Wyo., Lyman, Wyo., Silt, Colo., Smith Fork, Colo., Paonia, Colo. (including Minnesota unit), Florida, Colo., Pine River extension, Colorado-New Mexico, Emery County, Utah, central Utah (initial phase) Utah, Hammond N. Mex.

Brief statements on each of the initial participating projects are attached for filing with your committee, and further details can be found in the supplements to the Colorado River storage project report (H. Doc. 364, 83d Cong., 2d sess.).

A 12th project, the Eden project in Wyoming, was authorized in 1949 and is now under construction. That authorization provided that the project be assisted in repayment by power revenues from the Colorado River storage project. The Eden project is therefore included in the plan as a participating project.

The Secretary's supplemental report also included the Shiprock division of the Navaho project. Subsequent studies show that major features of the Navaho project, including the Navaho Reservoir, would be used jointly by the two divisions of the project. The Navaho Reservoir would also be used by the potential San Juan-Chama project. Thus, the Navaho project would be uneconomical of construction by divisions, and authorization of only the Shiprock division of the project would therefore be unsound.

For the information of the committee, however, a brief summary statement on the overall Navaho project prepared by the Bureau of Indian Affairs is attached. Further details on this project can be found in the feasibility report Navaho Project, New Mexico, January 1955, compiled by the Bureau of Indian Affairs.

WATER SUPPLY

The Colorado River compact in article III (a) apportioned from the Colorado River system in perpetuity to the upper basin and the lower basin, respectively, exclusive beneficial consumptive use of 71% million acre-feet per annum. There is a provision in article III (d) of the same compact that the States of the upper division (Colorado, New Mexico, Utah, and Wyoming) will not cause the flow of the river at Lee Ferry, the point of division between the upper and lower basins, to be depleted below an aggregate of 75 million acre-feet for any period of 10 consecutive years. These are the controlling and most important limitations with respect to water uses in the upper basin although there are other provisions in the compact relating to uses and deliveries of

water.

Substantial water development in the upper basin is impossible without regulation of the uneven flow of the Colorado River. Our studies show that without such control only about 58 percent of the water apportioned to the upper basin could be used.

During the past 59 years the historic annual flow of the Colorado River in the upper basin has varied from a high of 22 million acre-feet in 1907 to less than 5 million acre-feet in 1934. That span of years also presented extended periods of abnormal and subnormal flows, the most impressive being the extremely high flows of the period 1914–29 with historic annual flows averaging over 16 million acre-feet and the prolonged 25-year drought following thereafter with historic annual flows averaging only 11.5 million acre-feet. The long-time average flow, however, including periods of high runoff and drought, is sufficient to supply the allocated consumptive uses in the upper basin in addition to the downstream obligations.

The primary function of the storage units in the plan is to store water during years of high runoff for release during years of low runoff. Therefore, these cyclic conditions must be recognized in planning future uses of water in the upper basin.

A history of 59 years of river operation may or may not have revealed the full characteristics of the Colorado River. Yet, an initial

development of the magnitude now proposed has the assurance of the availability of sufficient water supply. Later stages of development would derive additional assurances as time goes on, or, if changes are required, time will permit appropriate adjustments in the later stages of development.

Under sound engineering and economic practices it would be impractical to completely regulate past historic flows of the river and its tributaries. Also, in years of extreme drought conditions the users of upper basin water would experience shortages in their supply which cannot be prevented. However, analyzing the upper basin's long-time program for developing its apportioned use of 712 million acre-feet per annum we found that such occasional shortages would be within the limits of normal irrigation, industrial, and municipal operations. The initial storage project units would provide for a greater amount of replacement storage than would be needed to permit the increase in consumptive use which would result from the initial development. However, these large storage facilities would develop the optimum power potential of these sites necessary to meet the demands of the region. These large power and storage units would also fit into any subsequent phase of the upper basin development which may be authorized.

A start on the required storage facilities in advance of their actual need is imperative because of the time element involved in the construction and initial filling of the storage reservoirs. Apportioned water not presently consumed in the upper basin would greatly facilitate the initial filling of the reservoirs.

Through electrical interconnection between Glen Canyon, Echo Park, and existing powerplants in the lower basin a first filling of the storage reservoirs could be attained with no interruption in delivery of firm electric energy to existing and potential customers on the river's system.

The time required to initially fill the Glen Canyon and Echo Park Reservoirs will largely depend upon the amount of runoff in the river. Under very favorable runoff conditions the filling period could be less than 5 years whereas a much longer period would be necessary under extreme drought conditions.

In either event, however, dead storage levels at Glen Canyon and at Echo Park could be attained during the period of construction of the dams, thereby providing the heads necessary for initial power generations.

Since the initial participating projects do not require the full capacity of Glen Canyon and Echo Park Reservoirs for regulatory purposes, there would be no immediate need to completely fill these reservoirs. Thus the initial filling process can be readily adapted to the amount of runoff and downstream demands for water and firm electric energy. This initial filling process would not violate the terms of the Colorado River compact.

The total consumptive use of water in the upper basin by all constructed projects, those authorized and projects under construction, will be approximately 212 million acre-feet, or one-third of the annual allotment of 72 million acre-feet to the upper basin. The 11 participating projects recommended in the Secretary's supplemental report

would increase present stream depletion by an additional 400,000 acrefeet annually.

Average evaporation from the recommended Echo Park and Glen Canyon storage units would amount to about 613,000 acre-feet annually. The units and projects recommended for authorization would thus involve an increased use of approximately 1 million acre-feet per annum. With accelerated development in the future, the remainder (4 million acre-feet per annum) of the upper basin's share of the Colorado River water may be put to beneficial use within the next 75 years.

Our studies show that the recommended units and projects would have no material effect on the quality of water downstream. With respect to later phases of development, the plan provides for additional gaging and sampling stations to supply data for continued analysis and scrutiny as each phase approaches authorization.

Our analysis of the quality of water at Lee Ferry reveals for the critical period of low flow (1931-47) concentrations of dissolved salts averaging 0.78 ton per acre-foot (575 parts per million) corresponding to uses totaling 22 million acre-feet per annum in the upper basin. An average concentration of 0.85 ton per acre-foot (625 parts per million) or an increase of about 9 percent is anticipated at Lee Ferry following completion of the recommended Glen Canyon and Echo Park storage units and the 11 initial participating projects, with a corresponding use then totaling about 312 million acre-feet.

With full use of the 712 million acre-feet per annum allotment in the upper basin, the average concentration of dissolved salts at Lee Ferry is estimated at about 1.20 tons per acre-foot or 880 parts per million.

Under any of the above conditions concentrations and type of salts are well within the standard range for irrigation water designated by the United States Salinity Laboratory at Riverside, Calif., as "good to permissible," and within the range of practical treatment for municipal and industrial purposes.

COST, ALLOCATIONS, AND REPAYMENT

The total construction cost of the initial units and participating projects is estimated at $930 million as summarized in table 1. This cost includes $7,287,000 for the authorized Eden project now nearing completion, $2,035,000 expended on the Paonia project under a previous authorization, and $21 million proposed for recreational development of the Dinosaur National Monument. This cost is based on January 1953 price levels and if adjusted to October 1954 price levels would be reduced by about 1 percent.

Also included is the cost of a transmission system necessary to deliver electrical energy to power market centers in the upper basin States and to tie in with the lower basin system.

If the Federal Government construct's only the interconnecting trunkline, with the remainder of the system to be constructed by nonFederal interests, the estimated Federal construction cost would be reduced and the purchase price for project power to those nonFederal interests decreased.