Appraisal Report Central Arizona Project

Document: "Appraisal Report Central Arizona Project-Chapter III", January 1962, page 23CHAPTER III - WATER SUPPLY This chapter presents the existing hydrologic conditions and water supply and operation under assumed project conditions. Present Water Supply Within the Central Arizona Project area, both surface- and ground-water supplies are available. The surface sources are natural flows, return, waste, and effluent flows, and storage on upper reaches of the major streams. The ground-water sources are the underground reservoirs filled prior to man's recent activity and continuously recharged by surface waters applied to the areas over which development has occurred. Rainfall in the developed areas generally is not significant as a source of water for crop production or ground-water recharge. The water supply studies for this appraisal are reconnaissance in nature and limited by the data presently available. In analyzing the present water supply, the period 1921-1959 has been considered to be representative of average surface-water conditions which might be expected in areas having upstream storage available. The average annual long-term surface-water supply was determined from the available records of diversions associated with the inflow to major storage reservoirs modified as necessary to reflect increasing reservoir storage capacity and water adjudications. In areas where surface water diversions are not directly influenced by upstream reservoirs, shorter term periods of record were used in order to reflect present conditions. These areas include the Gila River above Coolidge Dam, San Pedro River, and the lower reach of the Gila River below the confluences of the Salt and Agua Fria Rivers. 23Epson Perfection 4870 Photo, 400 dpi, 8 bit, 1,025,709 byte