at the headworks. The canal follows the river for the first 22 miles. The initial capacity is maintained for 15 miles to Syphon Drop, at which point 2,000 second-feet, carried for the Yuma project, is delivered to the Syphon Drop power plant. This plant, although located on the California side, is operated by the United States for and as a part of the Yuma project, Arizona. A portion (approximately 800 cubic feet per second) of this is carried under the river through a siphon to the Yuma Canal system, and the balance is discharged into the river through the Syphon Drop power plant. A capacity of 13,155 cubic feet per second is maintained for the next 7 miles, to Pilot Knob. At this point, water may be discharged into the river either through the projected Pilot Knob power plant, or the Pilot Knob wasteway. In either event, it reaches the river above the Mexican boundary and above the works controlling the heading of the Alamo Canal. These works are in the United States. They comprise Rockwood Gate, which controls the amount diverted from the river into the headworks of the Alamo, and Hanlon Heading, which controls the amount thereof passing from the headworks into Mexico. These control works are to be operated and maintained by the International Boundary and Water Commission under the terms of the Mexican water treaty (appendix 1405). No part of the water carried by the All-American Canal can be physically diverted into Mexico except through structures (Rockwood Gate and Hanlon Heading) controlled by the International Boundary and Water Commission. The All-American Canal turns west at Pilot Knob, roughly paralleling the border, with a capacity of 10,155 cubic feet per second for 14 miles to drop No. 1. At that point the Coachella branch takes out, with a capacity of 2,500 second-feet. This branch is 119 miles long, carrying water to the Coachella Valley. (See ch. XI (E) above.) Of this 2,500 cubic feet per second, 1,000 is carried for Imperial Irrigation District, for use on the East Mesa, which this branch traverses for 49 miles. Beyond that point, the capacity, now reduced to 1,500 cubic feet per second, is maintained to the boundary of the Coachella district, where it gradually tapers off to 425 cubic feet per second. The main canal from the junction of the Coachella branch (drop No. 1) continues west 44 miles, gradually reducing in capacity from 7,655 to 2,655 cubic feet per second. The main All-American Canal is thus 80 miles long, and the Coachella branch 119; water is carried for Coachella a total of 155 miles, including the common sections. The Gila Canal (referred to in ch. XII (H)) takes off from the headworks at the eastern end of Imperial Dam to serve lands of the Gila project, Arizona.25 25 For a description of the Gila project, see hearings, House Committee on Appropriations, or the Interior Department Appropriation Act for Fiscal Year 1949, p. 1156. H. Summary of Interests in All-American Canal In general, the various All-American Canal contracts provide that costs shall be allocated on the basis of capacities assigned to each agency, except that the capacity for the Yuma project is to be provided without cost to that project or the United States, save for turn-out structures. The share of the Gila project in the cost of Imperial Dam and certain portions of the All-American Canal has not been determined as of the date of publication. The Reclamation Bureau to date has not published tables setting up either the allocation of costs nor basis for determining allocations. The assignment of capacities in various portions of the canal is shown on the following table: TABLE 5.-All-American Canal: Assignment of capacities 1 Cost of capacity for Yuma project is charged to other contractors. Yuma project pays cost of turn-out structures only. NOTE. Imperial Dam is a part of the All-American Canal and also serves the Gila project in Arizona (2,400 cubic feet per second). I. Effect of the Mexican Water Treaty on the AllAmerican Canal The treaty with Mexico, February 3, 1944 (appendix 1405), contained a number of provisions relating specifically to the All-American Canal. Article 11 (c) of the treaty provides that after Davis Dam and Reservoir are placed in operation (see appendix 1214, re Davis Dam) until January 1, 1980, the United States shall deliver 500,000 acre-feet annually, and after January 1, 1980, 375,000 acre-feet annually, at the international boundary line by means of the AllAmerican Canal. Article 12 (b) obligates the United States to construct Davis storage dam and reservoir within 5 years from the date of the entry into force of the treaty (which was November 8, 1945). Article 12 (c) obligates the United States to construct or acquire works necessary to convey a part of the waters allotted to Mexico to the Mexican diversion points on the international land boundary. Article 14 provides that in consideration for the use of the AllAmerican Canal for the delivery of water to Mexico as provided in articles 11 to 15, Mexico shall pay to the United States its proportion of the cost incurred in the construction of Imperial Dam and the section of the All-American Canal from Imperial Dam to Pilot Knob, and a proportionate part of the annual cost of operation and maintenance of these facilities. Article 14 (b) provides that in the event revenues from the sale of hydroelectric power generated at Pilot Knob become available for the amortization of part or all of the cost of the facilities named in article 14 (a), the part that Mexico shall pay of the cost of these facilities shall be reduced or repaid in the same proportion. Such revenues shall not become available until the cost of any works constructed for the generation of power are fully amortized from revenues derived therefrom. Article 15 provides for the setting up of an annual schedule to cover the delivery of water at the boundary line by means of the All-American Canal, the schedule to be formulated by the International Boundary and Water Commission, subject to certain limitations. By article 15 (d), the United States declared its intention. to cooperate with Mexico in attempting to supply additional quantities of water under certain circumstances through the All-American Canal, if such use of the canal and facilities will not be detrimental to the United States, provided that such deliveries shall not have the effect of increasing the total schedule of deliveries to Mexico. These provisions are at variance with the stipulation in section 1 of the Boulder Canyon Project Act 26 that the Hoover Dam and AllAmerican Canal should be constructed for storage and for the delivery of the stored waters thereof for reclamation of public lands and other beneficial uses exclusively within the United States-and the authorization in that section for construction of— * a main canal and appurtenant structures located entirely within the United States, connecting with the Imperial and Coachella Valleys in Californiaas well as the provisions in section 7 granting to American districts and agencies the right to develop power and apply the net proceeds as stipulated in that section. So also with section 7, providing for the transfer of title of certain parts of the canal to the American districts interested. As of this writing, negotiations between the affected districts and the United States to accomplish the adjustments made necessary by the treaty are under way, but have not been consummated. 27 26 Act of December 21, 1928 (45 Stat. 1057) (appendix 401 herein). 27 See further references in ch. XIV. J. Transfer of Operation and Maintenance of the AllAmerican Canal On February 28, 1947, the Secretary of the Interior transferred to the Imperial Irrigation District operation and maintenance of the main All-American Canal west of engineer station 1098 (Pilot Knob). As of this writing the operation and maintenance of Imperial Dam, the portion of the main canal from Imperial Dam to Pilot Knob, and the Coachella branch, have not been transferred.28 28 See hearings, House Committee on Appropriations, Interior Department appropriation bill for fiscal year 1949, pp. 1597-1614. RELATED PROJECTS A number of important projects, built or authorized, are related directly or indirectly to the Boulder Canyon project. The project itself, as previously outlined, comprises Hoover Dam, Hoover Dam power plant, and the All-American Canal. The Hoover Dam transmission lines, although privately financed, are such an integral part of the project that they are discussed, supra, as a part of the project. The works more or less directly related to the Boulder Canyon project, built or authorized to date, in general order from north to south, are as follows: A. Davis Dam, 67 miles below Hoover Dam. C. Colorado River aqueduct, diverting from the reservoir im- D. Alamo Dam (on the Bill Williams River), on the margin of Parker Dam Reservoir. E. Headgate Rock Dam (Colorado River Indian Reservation), 14 F. Colorado River front work (levees and channel control), from G. Palo Verde weir (Palo Verde Irrigation District), 43 miles below Headgate Rock Dam. H. Gila project (Imperial Dam), 90 miles below the Palo Verde weir and 22 miles above the Mexican boundary. I. Yuma project (Laguna Dam), 5 miles below Imperial Dam. J. Rockwood Gate and Hanlon Heading, immediately above the upper Mexican boundary. K. Morelos Dam (in Mexico and Arizona), about 1 mile below the upper Mexican boundary, in the limitrophe section of the river. These, together with the Comprehensive Plan of Development of the Colorado River, are identified below. A. Davis Dam (1) Background and name of Davis Dam.-A dam at this site was proposed by A. P. Davis and J. B. Lippincott in the First Annual Report of the Reclamation Service (H. Doc. 79, 57th Cong.). Such a dam, for reregulation of the discharges from Hoover Dam, was con |