P.O. Abbott | Geology Reports

USGS1987

Hydrology of the U.S. Army Pinon Canyon maneuver site, Las Animas County, Colorado

The U.S. Department of the Army (Fort Carson Military Reservation) has acquired 381 sq mi of semiarid rangeland in southeastern Colorado for mechanized military maneuvers. The study area, known as the Pinon Canyon Maneuver Site, drains into the Purgatoire River, a major tributary of the upper Arkansas River. A multidisciplined hydrologic investigation began in October 1982. The primary aquifer in the Maneuver Site is the Dakota-Purgatoire. Well yields generally range from 10 to 500 gal/min. Dissolved solids concentrations in groundwater ranged from 195 to 6,150 mg/L. Streamflow in the Purgatoire River is perennial. Tributaries draining the Maneuver Site are intermittent or ephemeral and contribute only about 4.4% of the streamflow of the Purgatoire River downstream from the Maneuver Site. Flood frequencies were calculated by using the log Pearson III procedure and compared well with a regional estimating technique that was developed that uses physical drainage-basin characteristics. Calcium and sulfate are the predominant ions in the surface water of the area. Time-series plots indicate that instream water-quality standards for nitrate and metals are exceeded. About 80% of the suspended-sediment load is transported by rainfall runoff, which occurs less than 8% of the time. Ephermal tributaries contributed less than 25% of the suspended-sediment load transported to the Purgatoire River downstream from the Maneuver Site. Historic annual mean sediment yields were measured for 29 small watersheds. Sediment yields were measured for 29 small watersheds. Sediment yields ranged from 9.5 to 1,700 tons/sq mi. Sediment yields were estimated by a multiple-linear-regression model developed by using physical drainage-basin characteristics and by the Pacific Southwest Interagency Committee method. (USGS)

Water-Resources Investigations Report↗

USGS1985

Selected climatological and hydrologic data, Raton basin, Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico

The hydrology of the coal-bearing Raton Basin of Colorado and New Mexico was investigated by the U.S. Geological Survey. Data in the report were collected from 1977 to 1982, mainly in the watersheds of the Apishapa and Purgatoire Rivers; data from the Cucharas, Canadian, and Vermejo River watersheds are also included in the report. The report contains records of precipitation, temperature, relative humidity, evaporation, and wind movement at U.S. Geological Survey and U.S. Army Corps of Engineers meteorological stations; records of soil water collected by the U.S. Geological Survey; records of stream discharge and quality at U.S. Geological Survey gaging stations and miscellaneous sites; and a variety of ground-water data. The ground-water data includes records of 231 wells, springs, and mines, including 87 chemical analyses of the water, recorded water levels in 29 observation wells, results of 125 aquifer tests, and 87 logs of wells and test holes. (USGS)

Open-File Report↗

USGS1985

Description of water-systems operations in the Arkansas River basin, Colorado

To facilitate a current project modeling the hydrology of the Arkansas River basin in Colorado, a description of the regulation of water in the basin is necessary. The geographic and climatic setting of the Arkansas River basin that necessitates the use, reuse, importation, and storage of water are discussed. The history of water-resource development in the basin, leading to the present complex of water systems, also is discussed. Municipal, irrigation, industrial, and multipurpose water systems are described. System descriptions are illustrated with schematic line drawings, and supplemented with physical data tables for the lakes, tunnels, conduits, and canals in the various systems. Copies of criteria under which certain of the water systems operate, are included. (USGS)

Water-Resources Investigations Report↗

USGS1984

Water-resources appraisal of the upper Arkansas River basin from Leadville to Pueblo, Colorado

Water used for agriculture and stock and municipal supplies in the upper Arkansas River basin is derived mostly from the Arkansas River and its tributaries. The flow regime of the river has been altered by increased reservoir capacities and importation of 69,200 acre-feet per year from the Colorado River drainage through transmountain diversions. An estimated 10.2 million acre-feet of hydrologically recoverable water is present in the first 200 feet of basin-fill alluvium. Well yields of 300 gallons per minute have been reported for the Dakota-Purgatoire aquifer aquifer located east of Canon City. Water quality of ground- and surface-water resources are generally acceptable for agriculture and stock watering, but concentrations of iron, manganese, sulfate, pH, and hardness may exceed recommended drinking-water criteria during periods of river low flow. Concentrations of mercury, selenium, and select radiochemical constituents also were high in the Dakota-Purgatoire aquifer. Dissolved solids increased downstream and in local areas as a result of water use and in the Leadville area because of mine drainage. (USGS)

Water-Resources Investigations Report↗

USGS1983

Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

Area 61 is located on the Colorado-New Mexico boundary in Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico, and includes the Raton Mesa coal region. The 5 ,900-square-mile area is an asymmetrical structural trough bounded by the Rocky Mountains on the west and the Great Plains on the east. The area is drained by the Huerfano, Apishapa, Purgatoire, and Canadian Rivers (and their tributaries), all tributary to the Arkansas River. The principal coal-bearing formations are the Vermejo Formation of Late Cretaceous age and the Raton Formation of Late Cretaceous and Paleocene age. Much of the coal in the area is of coking quality, important to the metallurgical industry. Topographic relief in the area is greater than 8,700 feet, and this influences the climate which in turn affects the runoff pattern of area streams. Summer thunderstorms often result in flash floods. Virtually all geologic units in the region yield water. Depth to ground water ranges from land surface to 400 feet. Surface and ground water in the area contain mostly bicarbonate and sulfate ions; locally in the ground water, chloride ions predominate. Potential hydrologic problems associated with surface coal mining in the area are water-quality degradation, water-table decline, and increased erosion and sedimentation.

Open-File Report↗

USGS1983

Hydrology of Area 61, Northern Great Plains and Rocky Mountain Coal Provinces, Colorado and New Mexico

Area 61 is located on the Colorado-New Mexico boundary in Huerfano and Las Animas Counties, Colorado, and Colfax County, New Mexico, and includes the Raton Mesa coal region. The 5 ,900-square-mile area is an asymmetrical structural trough bounded by the Rocky Mountains on the west and the Great Plains on the east. The area is drained by the Huerfano, Apishapa, Purgatoire, and Canadian Rivers (and their tributaries), all tributary to the Arkansas River. The principal coal-bearing formations are the Vermejo Formation of Late Cretaceous age and the Raton Formation of Late Cretaceous and Paleocene age. Much of the coal in the area is of coking quality, important to the metallurgical industry. Topographic relief in the area is greater than 8,700 feet, and this influences the climate which in turn affects the runoff pattern of area streams. Summer thunderstorms often result in flash floods. Virtually all geologic units in the region yield water. Depth to ground water ranges from land surface to 400 feet. Surface and ground water in the area contain mostly bicarbonate and sulfate ions; locally in the ground water, chloride ions predominate. Potential hydrologic problems associated with surface coal mining in the area are water-quality degradation, water-table decline, and increased erosion and sedimentation. (USGS)

Water-Resources Investigations Report↗