| OCR Text |
Show PART II PRESENT STATUS OF IRRIGATION River Subregion, k8 percent in the Upper Main Stem Subregion, and 19 per- cent in the San Juan-Colorado Subregion. A reservoir upstream regulates the streamflow and provides clear water of excellent quality for irrigation downstream. The Green River (except within Flaming Gorge Reservoir), the San Juan River, and the Colorado River above Glenwood Springs, Colo., gener- ally do not have contents of total dissolved solids exceeding 500 mg./l. The Colorado River, extending from Glenwood Springs to Lee Ferry, has total dissolved solids varying between 500 mg./l. and 1,000 mg./l. Sa- linity hazards for irrigation in the region are considered low to medium for the Green River, the San Juan River, and the Colorado River above Glenwood Springs, and medium to high for the Colorado River below Glen- wood Springs. Water of these main rivers is suitable for most irrigated agriculture. The water of some tributaries of the Green, San Juan, and Colorado Rivers offers possible water quality problems with regard to its use for irrigation. These streams are generally small and are comprised mostly of return flows from irrigation upstream. Little, if any, of this water is reused for irrigation without dilution with better quality water from other streams. |
