| OCR Text |
Show PART II PRESENT STATUS OF IRRIGATION Alluvial soils derived largely from marine shale are irrigated in lower valley lands of Colorado. Irrigated lands in the New Mexico segment vary in elevation from lj-,900 to 6,000 feet. Annual precipitation averages about 8 inches and the average frost-free period is l6o days. The soils of the river valleys are alluvial, largely deposited on fans by the intermittently flowing tributaries entering the river valley. Lands near the outer edges of the valleys are moderately steep and sandy. They become flatter and finer textured near the stream channel. Deep percolation losses of irrigation water on the upper slopes often create seepage and salinity problems in the bottom lands. Predominant crops are hay, irrigated pasture, corn, orchards, beans, and small grains. Truck gardening increased signifi- cantly in the San Juan and Animas Valleys immediately prior to 1965. It has been demonstrated that the area is capable of growing excellent qual- ity vegetables with high yields. Irrigation in the Navajo Reservation, comprising the Arizona segment of the San Juan-Colorado Subregion, has been limited to development of intermittent flows of Chinle Creek and other southern tributaries of the San Juan River. Some 2k small Indian project areas including about 10,900 acres are now irrigated. About 1,200 acres of this land in the Many Farms Project area receive nearly a full water supply. The remaining Ik |
