| OCR Text |
Show PART II PRESENT STATUS OF IRRIGATION Meadow hay and pasture provide feed for livestock, complementing utilization of surrounding rangeland in the Upper Colorado Region. Irrigated mesa and terrace lands occur at elevations of 5,500 to 7^500 feet in western and southwestern Colorado. These are primarily reddish-brown, medium- to moderately fine-textured soils of aeolian and alluvial origin formed on an undulating topography. The soils are deep and moderately deep over glacial outwash gravel, sandstone, or shale. They are permeable, retain moisture well, are easy to till, and have no salinity or alkali problems. By 1965 there were 52,900 acres irrigated in the New Mexico segment of the San Juan-Colorado Subregion, located primarily along the San Juan, Animas, and La Plata Rivers of the San Juan Basin. A few sparsely scat- tered tracts are located on the Navajo Indian Reservation south of the San Juan River on small ephemeral streams originating in the Lukachukai and Chuska Mountain Ranges. These comprise part of the Region's short supply cropland acreage. Except in a very few extremely dry years, the natural runoff of the San Juan and Animas Rivers has provided essentially a full irrigation supply for lands served by them. The flows of the La Plata River, however, are insufficient in most years to serve lands along its course. 13 |
