Identifying Changes in Background Water-Quality Conditions, Arkansas River and Fountain Creek, near Pueblo, Colorado

Location and description of the study area

The study area is located in the vicinity of Pueblo, Colorado, and extends about 32 miles from the Arkansas River at Portland site to the Arkansas River near Avondale site.

River elevations along this reach range from 5,021 to 4,509 feet. The area is characterized by a semiarid climate with a mean annual precipitation of about 12 inches (Pielke and others, 2002). Mean annual humidity is relatively low at about 36 percent. The range in daily temperature averages about 18 degrees Celsius. Streamflow in the Arkansas River exhibits considerable seasonal variability with the majority of the total annual streamflow resulting from snowmelt runoff in the Rocky Mountains west of the study area. Streamflow between 1986 and 2001 averaged 732 cubic feet per second at the site Arkansas River above Pueblo and 999 cubic feet per second at the site Arkansas River near Avondale. The average streamflow at the site Fountain Creek at Pueblo was 166 cubic feet per second during 1986-2001.

Map of study area, lower Arkansas River in the vicinity of Pueblo, CO.