RS-06 Colorado’s Hydrothermal Resource Base: An Assessment


As part of its effort to more accurately describe the nation’s geothermal resource potential, the U.S. Department of Energy, Division of Geothermal Energy contracted with the CGS to appraise the hydrothermal (hot water) geothermal resources of Colorado. Includes descriptions of 58 individual thermal areas in 25 counties. 144 pages. 46 figures. 6 tables. Digital PDF download. RS-06D

This investigation by the CGS attempts to refine earlier estimates of Colorado’s geothermal resources. Colorado’s geothermal resource potential is expressed in the over 160 thermal springs and wells (temperatures in excess of 20°C) found throughout the western one-half of the state. While these springs and wells are found in a variety of geological environments, the majority of them are associated with the Rio Grande Rift of the San Luis Valley and Upper Arkansas Valleys, and with the San Juan and La Plata Mountains of southwestern Colorado.

To aid in appraising the hydrothermal resources of Colorado, geothermometer models were utilized to estimate the subsurface reservoir temperatures of the various thermal areas. The models used were: Silica, Mixing Model I and II, Na-K, and Na-K-Ca. Probable subsurface temperatures range from a low of 20°C at Dexter Warm Spring in the southern San Luis Valley to high of over 200°C at both Cottonwood Hot Springs and Mount Princeton Hot Springs areas.

Using published data, the areal extent of each thermal system was estimated and the amount of heat contained in the system calculated. These estimates showed that the total amount of heat contained in the hydrothermal systems in Colorado ranged from 4.8782 Quads to 13.2386 Quads.