Salinity Problems in the Lower Colorado River Area

Document: State of California, Colorado River Board of California, "Salinity Problems in the Lower Colorado River Area," September, 1962, page 2222 COLORADO RIVER BOARD Sources and relative proportions of the total flow and salt load at the northerly boundary in the period October 1961 through February 1962 are shown diagrammatically on Plates 6 and 7 and quantitatively on the following table. SOURCES OF WATER AND MINERALS Colorado River at Northerly International Boundary * October 1961 Through February 1962 Water Minerals Percent of total at Percent of total at Source A.f. boundary Tons boundary MEASURED DRAINAGE RETURNS Wellton-Mohawk 80,510 18.9 661,030 54.1 Gila River 1,479 0.3 12,510 1.0 North Gila Valley 2,063 0.5 4,010 0.3 South Gila Valley 14,101 3.3 49,450 4.0 Subtotal Arizona 98,153 23.0 727,000 59.4 Yuma Reservation Division 18,558 4.3 26,160 2.2 Subtotal California 18,558 4.3 26,160 2.2 Total Arizona and California 116,711 27.3 753,160 61.6 MEASURED WASTEWAY RETURNS Imperial Dam release and seepage 104,462 24.5 117,000 9.6 Gila project 15,682 3.7 17,560 1.5 California wasteway (siphon drop) 35,980 8.4 40,300 3.3 Pilot Knob 126,560 29.7 141,750 11.6 Total Arizona and California 282,684 66.3 316,610 26.0 UNMEASURED NET RETURNS Imperial Dam to northerly boundary t 27,185 6.4 151,530 12.4 MEASURED NORTHERLY BOUNDARY 426,580 100 1,221,300 100 * Water available at Morelos Dam. + Northerly boundary less sum of all measured return. The Reservation Division of the Yuma Project is the only project on the California side below Imperial Dam which contributes drainage return to the river at the boundary. The total quantity of return in calendar year 1961 was about 51,600 acre-feet, or an average of about 70 cfs. Quality samples indicated about 1,000 ppm, or about 1.4 tons of total dissolved solids per acre-foot. Annual discharge from the Reservation Division including seepage from the All-American Canal picked up by the two drains constitutes only about 4 percent of the total annual return flow to the Colorado River between Imperial Dam and the northerly boundary. For the five months, October 1961 through February 1962, the discharge from the Reservation Division drains was 4.3 percent of of the total delivery at the boundary and carried 2.2 percent of the total salt load. Drainage water from the Valley Division of the Yuma Project has in general about twice as much mineral content as the Colorado River at Imperial Dam. This water has been used for irrigation for many years without complaint by farmers on the SonoraEpson Perfection 4870 Photo, 400 dpi, 8 bit, 2,137,860 byte