AZ vs. CA:24 California Exhibits, Vol. XXIV; Miscellaneous

page 76

76 PROBLEMS OF IMPERIAL VALLEY AND VICINITY. Ockerson levee, built by United States in 1911, length 24£ miles. This was partly destroyed shortly after its construction and has not since been repaired. Operation difficulties.-A great deal of difficulty is being experienced by the Imperial project in its operation, due to the fact that there is no permanent diversion dam and sluicing basin at ?the inlet, which condition requires the construction of a temporary diversion damr which is needed to enable the diversion of sufficient water through the low period; and on account of the insufficient desilting at the diversion point a large expense is incurred in dredging canals. The present^ course of the river is following the Bee River channel to the southwest into Volcano Lake and it is, silting up the lake to such an extent as to endanger the Volcano Lake levee. Plans are now being considered by the district to divert the river to the south and thus keep it out of Volcano Lake. Irrigation plan.-The present plan of the project provides for diversion from the west side of the Colorado River at the Rockwood heading, about 7,000 feet above the Mexican line, and the control of the low-water diversion by temporary rock-and-brush weirs; a main canal through the Imperial Valley of Mexico following mainly the old Alamo River channel; the diversion of water into submains and laterals for irrigation of lands in Mexico; the division of the main canal, a short distance south of where it reenters the United States, into the east-side high line, east-side low line, central main and west-side main canals for the irrigation of the lands of the Imperial irrigation district. A diversion from Volcano Lake is also made to supplement the irrigation on the west side in Mexico and the United States. The present plan of flood control is by a levee extending from Hanlon heading southwesterly to near Volcano Lake and the Volcano Lake levee, extending from the west mesa, just north of the lake, northeasterly to the Inter-California Railroad embankment * and to the bank of the main canal. This forms a double defense except near the west side of the valley. It is planned to strengthen these leyees as required and also to repair the Ockerson levee near its crossing of Bee River and to extend it westerly on the north side of Bee River, a distance of about 5 miles, and at this point to cut a new river channel southwesterly from Bee River for a distance of about 4 miles, where it will discharge into an arroyo and onto lower ground and thus to keep it away from Volcano Lake and from threatening the Volcano Lake levee. Alternate plan.-It is proposed to divert at Laguna Dam of the United States Reclamation Service, to enlarge the Yuma project main canal to the siphon drop, and to construct an Ail-American canal from this point to near the border line of Mexico and thence west on the American side to the Imperial Valley. A contract has been entered into to this effect dated October 23, 1918, between the United States and the Imperial irrigation district. Details of this plan, including estimate, are outlined in the section devoted to Ipiperial Valley, this report. Power requirement.-The present Imperial project is all a gravity system ana no power is required for irrigation pumping.