Page:Popular Science Monthly Volume 70.djvu/19

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The total cost of the seventh and last attempt to control this irrigation system has been $40,000, or thereabouts. There are two headgates—one, of concrete, on the California side, and one, of wood, on the Mexico side. The one of concrete is built to stand the greater portion, by far, of the strain, and it has every appearance of being amply substantial. The cost of this gate alone was $24,770.47. It necessitated the excavation of 12,637.1 cubic yards of earth and 5,700.81 cubic feet of rock, and required the use of 1,335 barrels of cement, 1,204.85 cubic yards of sand, gravel and rock, 25,722 pounds of steel bars for reinforcement and 791 pounds of expanded metal for gate facings. The work is being engineered by Mr. C. F. Cory, an engineer of wide repute.

Although these dams or head-gates seem to promise a solution to the Salton Sea problem, there is nevertheless excuse for apprehensions of further trouble. The banks of the Colorado River in this vicinity are soft and gravelly and very easily eroded, and on this account there will always be the possibility of new channels being cut around these head-gates, especially during flood seasons.