The Upper Arkansas John Martin watershed covers an area of 11,219 square kilometers and is located in east-central Colorado. The hydrology of the watershed is dominated by the Arkansas River, which flows through the area and provides water for irrigation, municipal, and industrial uses. The watershed experiences a semi-arid climate, with low precipitation and high evaporation rates. The snowpack in the area is typically light and melts quickly, contributing to the seasonal flow of the Arkansas River. The watershed is home to several reservoirs, including John Martin Reservoir, which provides water storage and recreation opportunities. The reservoir constituents include sediment, nutrients, and pollutants from agricultural runoff and urban areas. Climate trends in the area include increasing temperatures, decreased snowpack, and changes in precipitation patterns. These trends have implications for water availability, agriculture, and ecosystem health in the watershed.