6.5 PARADOX BASIN
The Paradox Basin is an elliptical-shaped structural depression located within the Colorado Plateau physiographic province in southwestern Colorado and southeastern Utah. In Colorado, the basin is bounded on the north by the Uncompahgre uplift, on the east by the San Juan Mountains, on the south by the San Juan Basin, and by the Utah-Colorado state line on the west (Figure 6.5-1). The basin covers approximately 14,000 square miles of which, 40 percent or, 5,600 square miles are located in Colorado.
The terrain is mostly composed of high plateaus with deeply incised canyons and dry arroyos. The San Miguel and Dolores Rivers, which are part of the Colorado River system, form the main surface-water drainage system in the Colorado portion of the Paradox Basin. Administratively, the basin lies in both Water Divisions 7 and 4.
In Colorado, the Paradox Basin is primarily located in Dolores, San Miguel, and western Montrose counties. Few people live in the Paradox Basin, with the 2000 Census recording only 1,844 people in Dolores County and 6,594 in San Miguel County. Agriculture has historically been an important industry in this region. According to the Colorado Division of Water Resource’s (DWR) well permit database, less than 2,000 bedrock wells are located in the basin, with most clustered around the population centers and river courses (Figure 6.5-1).