OCR Text |
Show -11- small a canal as possible at first, the minimum width is limited by the possibilities of mechanical construction. As planned, the canal will have a bottom width of 20 feet, side slopes of one to one, a grade of 8% inches per mile, and with 10 feet depth of water will carry 750 cubic feet per second, a sufficient amount for the irrigation of 150,000 acres. This can be inlarged [sic] from time to time by dredgers without interfering with the operation of the canal. Settling Basin. The large amount of sediment carried by the Colorado and the impossibility of flushing the canal will make necessary the construction of a settling basin immediately below the head gates. This basin will be merely an enlargement of the canal, and will be 350 feet in length by 100 wide. Its bottom will be 10 feet below the bottom of the canal. The heavier sands will be dropped in this basin and pumped back into the river by an hydraulic dredge. The clay and lighter silt that passes through will be carried by the greater velocity of the canal water onto the lands. Head Gates. I would prefer to build the diversion structure of masonry; but from an economical point of view, think it advisable to build of wood for the present, and replace by more permanent material when the canal requires enlargement. The wooden structure will be equally as safe as masonry for a period of ten years, and can be built for $10,000 while masonry would cost twice that amount. Other Structures. I would advise that all structures, bridges, drops, regulating weirs and gates be constructed of wood, and all estimates have been based on this material. |
Source |
Original book: [State of Arizona, complainant v. State of California, Palo Verde Irrigation District, Coachella Valley County Water District, Metropolitan Water District of Southern California, City of Los Angeles, California, City of San Diego, California, and County of San Diego, California, defendants, United States of America, State of Nevada, State of New Mexico, State of Utah, interveners] : California exhibits. |