River Basin compact of 1949. The Mexican Water Treaty of 1945 defines Mexico's rights to the use of water from the Colorado River system.

Colorado River compact

The Colorado River compact, signed November 24, 1922, and subsequently ratified by all signatory States and approved by Congress, has often been referred to as the "law of the river."

Articles II and III of the Colorado River compact are of particular significance and are quoted in full as follows:

As used in this compact:

ARTICLE II

(a) The term "Colorado River system" means that portion of the Colorado River and its tributaries within the United States of America.

(b) The term "Colorado River Basin" means all of the drainage area of the Colorado River system and all other territory within the United States of America to which the waters of the Colorado River system shall be beneficially applied. (c) The term "States of the upper division" means the States of Colorado, New Mexico, Utah, and Wyoming.

(d) The term "States of the lower division" means the States of Arizona, California, and Nevada.

(e) The term "Lee Ferry" means a point in the main stream of the Colorado River 1 mile below the mouth of the Paria River.

(f) The term "Upper Basin" means those parts of the States of Arizona, Colorado, New Mexico, Utah, and Wyoming within and from which waters naturally drain into the Colorado River system above Lee Ferry, and also all parts of said States located without the drainage area of the Colorado River system which are now or shall hereafter be beneficially served by waters diverted from the system above Lee Ferry.

(g) The term "Lower Basin" means those parts of the States of Arizona, California, Nevada, New Mexico, and Utah within and from which waters naturally drain into the Colorado River system below Lee Ferry, and also all parts of said States located without the drainage area of the Colorado River system which are now or shall hereafter be beneficially served by waters diverted from the system below Lee Ferry.

(h) The term "domestic use" shall include the use of water for household, stock, municipal, mining, milling, industrial, and other like purposes, but shall exclude the generation of electrical power.

ARTICLE III

(a) There is hereby apportioned from the Colorado River system in perpetuity to the upper basin and to the lower basin, respectively, the exclusive beneficial consumptive use of 7,500,000 acre-feet of water per annum, which shall include all water necessary for the supply of any rights which may now exist.

(b) In addition to the apportionment in paragraph (a), the lower basin is hereby given the right to increase its beneficial consumptive use of such waters by 1,000,000 acre-feet per annum.

(c) If, as a matter of international comity, the United States of America shall hereafter recognize in the United States of Mexico any right to the use of any waters of the Colorado River system, such waters shall be supplied first from the waters which are surplus over and above the aggregate of the quantities specified in paragraphs (a) and (b); and if such surplus should prove insufficient for this purpose, then, the burden of such deficiency shall be equally borne by the upper basin and the lower basin, and whenever necessary the States of the upper division shall deliver at Lee Ferry water to supply one-half of the deficiency so recognized in addition to that provided in paragraph (d).

(d) The States of the upper division will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75,000,000 acre-feet for any period of 10 consecutive years reckoned in continuing progressive series beginning with the first day of October next succeeding the ratification of this compact.

(e) The States of the upper division shall not withhold water, and the States of the lower division shall not require the delivery of water, which cannot reasonably be applied to domestic and agricultural uses.

(f) Further equitable apportionment of the beneficial uses of the waters of the Colorado River system unapportioned by paragraphs (a), (b), and (c) may be made in the manner provided in paragraph (g) at any time after October 1, 1963, if and when either basin shall have reached its total beneficial consumptive use as set out in paragraphs (a) and (b).

(g) In the event of a desire for further apportionment as provided in paragraph (f) any two signatory States, acting through their governors, may give joint notice of such desire to the governors of the other signatory States and to the President of the United States of America, and it shall be the duty of the governors of the signatory States and of the President of the United States of America forthwith to appoint representatives, whose duty it shall be to divide and apportion equitably between the upper basin and lower basin the beneficial use of the unapportioned water of the Colorado River system as mentioned in paragraph (f), subject to the legislative ratification of the signatory States and the Congress of the United States of America.

Mexican water treaty

The treaty between the United States of America and the United States of Mexico, effective November 8, 1945, allots to Mexico a guaranteed annual quantity of 1,500,000 acre-feet to be delivered in accordance with a schedule specifically set out in the treaty. When the United States section of the International Boundary Commission decides that there is a surplus of water in the Colorado River in excess of the amount necessary to supply uses in the United States and the guaranteed quantity of 1,500,000 acre-feet allotted to Mexico, the United States, by the express terms of the treaty, would undertake to provide a total quantity of 1,700,000 acre-feet to Mexico. Provision is made in the treaty for reduction of the guaranteed quantity to be delivered to Mexico in the event of extraordinary drought or serious accident to the irrigation system in the United States.

Upper Colorado River Basin compact

By the upper Colorado River Basin compact, approved by Congress April 6, 1949, the use of water apportioned the upper basin under the Colorado River compact is divided among the upper basin States. The upper basin compact also establishes the obligations of each State of the upper division with respect to the deliveries of water required to be made at Lee Ferry by the Colorado River compact.

Article III of the compact, part of which is quoted below, provides for the apportionment of the consumptive use of water.

(a) Subject to the provisions and limitations contained in the Colorado River Compact and in this compact, there is hereby apportioned from the Upper Colorado River system in perpetuity to the States of Arizona, Colorado, New Mexico, Utah, and Wyoming, respectively, the consumptive use of water as follows:

(1) To the State of Arizona the consumptive use of 50,000 acre-feet of water per annum.

(2) To the States of Colorado, New Mexico, Utah, and Wyoming, respectively, the consumptive use per annum of the quantities resulting from the application of the following percentages to the total quantity of consumptive use per annum apportioned in perpetuity to and available for use each year by the upper basin under the Colorado River Compact and remaining after the deduction of the use, not to exceed 50,000 acre-feet per annum, made in the State of Arizona.

Article IV outlines certain principles to be applied in determining the extent to which each State of the upper division will be required to curtail its apportioned consumptive use if a curtailment is necessary to permit the States to meet the Lee Ferry flow obligations provided in article III of the Colorado River Compact.

Article V pertains largely to the charging of storage losses. Paragraph (c) of this article, quoted below, is concerned with the use of reservoir sites and is of importance in the development of the water resources of the States of the upper division.

(c) In the event the Commission finds that a reservoir site is available both to assure deliveries at Lee Ferry and to store water for consumptive use in a State of the Upper Division, the storage of water for consumptive use shall be given preference. Any reservoir or reservoir capacity hereafter used to assure deliveries at Lee Ferry shall by order of the Commission be used to store water for consumptive use in a State, provided the Commission finds that such storage is reasonably necessary to permit such State to make the use of the water apportioned to it by this Compact.

Article VI, quoted below, provides for a determination of the quantity of the consumptive use of water for the upper basin and for each State of the upper basin.

The Commission shall determine the quantity of the consumptive use of water, which use is apportioned by Article III hereof, for the upper basin and for each State of the upper basin by the inflow-outflow method in terms of man-made depletions of the virgin flow at Lee Ferry, unless the Commission, by unanimous action, shall adopt a different method of determination.

Article VIII creates an interstate administrative agency to be known as the Upper Colorado River Commission. This article provides that the commission be composed of one commissioner representing each of the States of the upper division, designated or appointed in accordance with the laws of each such State and, if designated by the President, one commissioner representing the United States of America.

In anticipation of projects which require diversion and storage of water in one State for use in another State, article IX is included in the compact. This article, part of which is quoted in the following paragraphs, is of significance to the Colorado River storage project because, as to the appropriations of Colorado River water, it supersedes existing statutory law in some of the upper basin States which deny the right to divert water in one State for use in another State.

(a) No State shall deny the right of the United States of America and, subject to the conditions hereinafter contained, no State shall deny the right of another signatory State, any person, or entity of any signatory State to acquire rights to the use of water, or to construct or participate in the construction and use of diversion works and storage reservoirs with appurtenant works, canals and conduits in one State for the purpose of diverting, conveying, storing, regulating, and releasing water to satisfy the provisions of the Colordao River Compact relating to the obligation of the States of the upper division to make deliveries of water at Lee Ferry, or for the purpose of diverting, conveying, storing, or regulating water in an upper signatory State for consumptive use in a lower signatory State, when such use is within the apportionment to such lower State made by this Compact. Such rights shall be subject to the rights of water users, in a State in which such reservoir or works are located, to receive and use water, the use of which is within the apportionment to such State by this Compact.

Article IX also provides for acquisition of out-of-State property by donation, purchase, or through the exercise of the power of eminent domain. In addition it provides for administration of water-control facilities in one State for use of water in another State.

INVESTIGATIONS AND REPORTS

Previous investigations

Investigations of means to develop the waters of the upper Colorado River system were started by the Bureau of Reclamation in 1902, the year of the Bureau's organization. Within 3 years two major projects in the upper basin, the Uncompahgre in Colorado and the Strawberry Valley in Utah, were authorized for construction. A few years later the Grand Valley project in Colorado also was authorized. No significant action was then taken until 1928 when Congress, recognizing the need for further development, wrote into the Boulder Canyon Project Act a directive to the Secretary of the Interior to make investigations and publish reports on the feasibility of projects for irrigation, power, and other multiple uses for the purpose of formulating a comprehensive scheme of control and the improvement and utilization of the water of the Colorado River and its tributaries. In accordance with the congressional mandate, work was undertaken after 1928 on the tremendous task of classifying lands in the upper drainage basin, making water supply studies on the numerous tributary streams, and locating and investigating reservoir and canal sites. Prior to completion of these studies the Colorado-Big Thompson project and a few smaller projects were selected for construction. The basinwide studies, retarded by the war, were reported in a publication of March 1946, entitled "The Colorado River," a comprehensive report on the development of the water resources of the Colorado River Basin. The report was later printed as House Document 419, 80th Congress, 1st session. The report includes a description of the basin, its natural resources, needs, and problems. It describes present developments in the basin and presents a descriptive inventory of potential develop

ments.

The Colorado River report lists 134 projects as possibilities for future development of water resources within the natural drainage basin of the Colorado River. One hundred of these projects are located in the upper drainage basin. The report also lists potential projects for the export of water from the Colorado River system to adjoining basins. It points out that a comprehensive plan of water resources development could not be formulated until further detailed investigations were made and allotments of Colorado River water made to each of the States of the upper and lower basins. The report provided a basis for compact negotiations among the upper basin States which resulted in their compact of 1949.

Cooperating with the Bureau of Reclamation in the basinwide. investigations and contributing to the 1946 report were other agencies of the Department of the Interior, including the Geological Survey, National Park Service, Fish and Wildlife Service, Grazing Service, Bureau of Mines, Office of Indian Affairs, and General Land Office. The Forest Service of the Department of Agriculture and the Federal Power Commission also contributed to the report.

Scope of present investigations

Investigations leading to the present report have been conducted since 1946 to determine in greater detail than was done in the basin investigation the most attractive plan for providing river regulation, sediment retention, power production, and other benefits on the

Colorado River and its major tributaries above Lee Ferry. The investigations have been carried out in sufficient detail to establish an overall plan and to determine its engineering and economic feasibility. The various dams and other related works required by the plan are collectively designated the Colorado River storage project. The main stream investigations have been closely correlated with concurrent studies made of various projects to utilize the waters of the upper Colorado River system for irrigation and other purposes. Correlations have been made from the standpoints of water supply and storage requirements, and suggested financial relationships have been developed through which surplus power revenues of the Colorado River storage project would be used to assist irrigators in payment of costs of other projects that would utilize water of the upper Colorado River system. Projects that would be so assisted are referred to as "participating projects." Detailed reports have been completed on some participating projects and others are being prepared. All projects authorized subsequent to approval of the upper Colorado River Basin compact that would consume water of the upper Colorado River system are considered to be dependent on the storage project for an assured water supply. Such projects therefore are designated “dependent projects.'

Acknowledgments

This report has been prepared by the Department of the Interior and assembled under sponsorship of the Bureau of Reclamation. Important contributions to the report were made by the Upper Colorado River Compact Commission and States of the upper Colorado River Basin. Information also was obtained from the Federal Power Commission and other Federal agencies.