WSP10867 - Laserfiche WebLink

Home Browse Search

" Verde is a tributary of the Salt River. The flows of these streams are very erratic, and, to facilitate the irrigation development, reservoirs have been constructecl. "One of the early projects undertaken by the Bureau of Reclamation was to build the Roosevelt [leservoir on the Salt River. The present capacity of that reservoir is 1,400,000 acre-feet. On the Gila River, the Indian Irrigation Service have constructed the Coolidge Reservoir with a capacity of 1, 250,000 acre-feet, to control the flows of that stream, and the Verde River is being controlled by the Bartlett Reservoir, which has a capacity o~ 182,000 acre-feet. There are other reservoirs built on the Salt River. There is the Horse Mesa, with a capacity of 245,000 acre-feet; the Mormon Flat, with a capacity of 58,000 acre- feet; and the Stewart Mountain, with a capacity of 70,000 acre-feet. These reservoirs were built by the Salt River Valley Water Users Association, and construction is now under way for an additional reservoir at the Horseshoe site, which will have a capacity of 60,000 acre-feet. In addition to the surface reservoirs, the irrigation plan also utilizes a vast quantity of underground storage. At the present time there is a serious problem of the quality of water used for irrigation, espeCially at the lower end of that proj ect, I have examined records of water samples from wells throughout the area and I find that at the upper end the salinity of thE: water is 300 parts per milhon. For practical purposes, that is fresh water, However, as we progress down- stream the water becomes p~ogressively more saline. "Senator McFARLAND. Now, you are talking about the underground supply? "Mr. RITER. I am talking, Senator, about these. These are the wells, in the underground reservoir; yes. "Senator McFARLAND. Of course, that would be true of the others, too? " Mr~RI'IER._Ye s~sir~_b,ecall se_thaLLeilect.!uhe..mingling_oLwate1'6 from all sources. In the extreme lower end there are some wells that have as high as 7,500 parts per million of salts. The low flow discharged at Gillespie Dam, which is located at the lower end of the Phoenix area, has a salinity concentration of 6,000 parts per million. "Senator McFARLAND. Now, are you talking about the water in the river? "Mr. RITER. The water in the river. "Senator McFARLAND. The water in the river? "Mr. RITER. As it goes over the dam. That is where the samples were selected. "Senator McFARLAND. That is 6,000 parts? "Mr. RITER. 6,000 parts per millIOn; yes, sir. "Now, there was considerable discussion this morning with a previous witness regarding the amount of return flow from the central area. It is my -29-