Geology and Water Resources of the Spanish Valley Area, Grand and San Juan Counties, Utah (TP-32)

By: C. T. Sumsion

The Spanish Valley area covers about 144 square miles on the western slopes of the La Sal Mountains in southeastern Utah; within it, Spanish Valley comprises about 18 square miles. Altitudes of land surface within the area range from about 3,950 feet at the Colorado River near Moab to 12,646 feet at Mount Mellenthin in the La Sal Mountains. Principal streams in the area are Mill and Pack Creeks; they join near Moab, and Mill Creek enters the Colorado River. The climate ranges from arid and semiarid in the canyons and valleys at lower altitudes to generally humid and cool in the higher parts of the La Sal Mountains. The precipitation at Moab is fairly evenly distributed throughout the year; but slightly more falls during the winter than during the summer. Mean annual precipitation is about 8 inches at the city of Moab in Spanish Valley, and the weighted normal annual precipitation on the entire Spanish Valley area is about 15 inches.

This water-resources investigation was initiated in order to provide an estimate of the average annual water yield of the Mill Creek-Pack Creek drainage basin, the parts of that total yield available as surface water and ground water, the amount of ground water that might be recovered for beneficial use, and the effect of this use on the usable ground-water storage within the valley fill in Spanish and Moab Valleys. Detailed information has been sought which is basic to the establishment of sound policies for the development and management of water resources. The investigation was carried out as part of water-resources investigations in Utah with the Utah Division of Water Rights, Department of Natural Resources. Fieldwork was done during the period July 1967-November 1969.

Other Information:
Published: 1971
Pages: 45 p.
Location: Grand County and San Juan County
Media Type: Paper Publication