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 28POSSIBLE FUTURE CONDITIONS Water users in the international boundary area are at a distinct disadvantage because of their geographical location. By natural process alone, large quantities of minerals are dissolved and transported along the course of the Colorado River. It is not unlikely that existing projects and projects now authorized may soon be utilizing all the available water supply of the Colorado River Basin. Future main-stream water reaching the Lower Colorado River area will have increased in salinity through more intensive use and additional pollution. Expert testimony in the pending Supreme Court suit, Arizona v. California, indicates that under future conditions of upstream development the salinity of the river at Imperial Dam may get as high as 1.50 tons per acre-foot and possibly more. Such probability is of serious concern to all Lower Basin mainstream water users because of the potential necessity of applying more water or reducing irrigated acreage in order to maintain favorable salt balance, and because of the provision in the Colorado River Compact that "perfected rights" shall be "unimpaired." The problem of the Wellton-Mohawk Project and that at the Mexican border could become more aggravated also by the construction of the proposed Central Arizona Project. The planned diversion of about 1,200,000 acre-feet from the Colorado River to the Phoenix area probably would make it necessary to discharge quantities of salty water down the Gila River. In the 1947 report by the Commissioner of Reclamation on this proposed project it was estimated that if the project were constructed, the outflow from the project area for salt balance would amount to 376,000 acre-feet a year carrying nearly 2,100,000 tons of salt a year into the Lower Gila. The computation assumed that Colorado River water diverted into Central Arizona would carry an average salt load of about 1.1 tons per acre-foot. Expert testimony in Arizona v. California indicates that the future load in the Colorado River at the proposed point of diversion for the Central Arizona Project may be appreciably greater than assumed by the Bureau in 1947. Much consideration should be given to the potential effect on water quality of any proposed future project to use Colorado River System water. This page is the only one which creates any concern in Arizona. Bill Gookin would like to get Fannin to write a letter to Gov. Brown complaining; others think it is best left as it is, to avoid giving it undue emphasis. This is it, anyway. OBEpson Perfection 4870 Photo, 400 dpi, 24 bit, 2,336,907 byte