Under the provisions of this act and all amendatory and sup plementary acts, the Department of the Interior has become the principal and almost the sole developing agency in irrigation for the arid States. This work in the Interior Department is organ ized as a Bureau with a Commissioner located in Washington as the directing head, and with an engineering office in Denver, presided over by the Chief Engineer.
Under this law these works are required to be self-liquidating and contracts for repayment are usually made before construc tion begins. The majority of the contracts are made with the settlers organized as an irrigation district but in some instances they are made with the irrigators organized as associations. While the original intention was to use this act as an instrument for extending the irrigated area, its main value has been in provid ing the reserve of capital and the engineering knowledge and ex perience to undertake larger and more costly works than had previously been attempted.
Greater than the need for works for new lands was the need to conserve the wasted water to give an adequate water supply to land already under cultivation. Hence the Reclamation Act has been largely a rescue agency for providing a water supply to meet needs of existing development and especially to provide for the continued increased use of water due to increase in population, not only on the farms but in cities and towns, and for the ex panding needs of industries.
The money with which to begin the construction of these irri gation works was provided by making available the income from the sale of public lands and part of the revenue from oil and mining leases. After the works were built, they were to be paid for by the water users under them. From the outset the income from these different sources has been inadequate to pay for the construction of reservoirs and canals sorely needed to meet the increasing demands for water. The growth of cities increased the
demand on streams to meet the requirements for domestic and industrial uses. It soon became evident that the original provi sions for irrigation were inadequate. More water for the farms already under cultivation had to be provided. To cope with this situation Congress in 1914 loaned the Reclamation Fund $20, 000,000. Of this amount $10,000,000 has been repaid.
In 1928 an act was passed authorizing the construction of Boulder Dam. It had for its object the complete regulation of the flow of the Colorado River in order that the entire water supply might be made available for use for irrigation, domestic purposes, and generation of hydro-electric power, the money for this development to be provided by Congressional appropriations.
In 1933 the water conservation policy of these arid States was greatly accelerated by allotments from the emergency funds pro vided by Congress for public works administration. This made possible dealing with the emergency water needs of not alone a single community but of the State. A program of water utiliza tion was planned for Utah and Nevada, and in a lesser measure for some of the other States. Including Boulder Dam, the con struction of which was begun in 1931, the Federal reclamation program for the last five years has included the works described below : When undertaken in 1931 the Boulder Canyon project was the most important irrigation enterprise in the United States, both in the amount of money to be expended and because of its out standing engineering features. The project has three construction features—the 726-foot Boulder dam, a power plant of 1,835,000 horsepower installed capacity, and the All-American canal. This 8o-mile canal will carry water from the Imperial diversion dam on the Colorado River to provide water for 500,00o acres in the Imperial Valley of Southern California, now irrigated and ulti mately to irrigate an additional 500,00o acres. This will include the Coachella Valley. The Imperial district is now irrigated by an inadequate system with its main canal running through Mexico.