Chapter 1 Page 3

Chapter 1, Page 3 of 4

Climate and Water

An area’s climatic conditions will ultimately control its ground-water resources because the source of ground water is infiltration of precipitation. Colorado’s location, far inland from any ocean, and its variable topography greatly influence weather patterns producing a semiarid climate with hot summers and cold winters. These climatic conditions produce a mean annual statewide precipitation of 17 inches. On average, 81 percent of the precipitation that falls on the land surface is lost through evapotranspiration producing a water balance deficit over most of the state, with the exception of the higher mountainous regions (Figure 1.3). While the amount of water recharged to a local aquifer is dependent upon climatic conditions, land surface characteristics, and aquifer hydraulic parameters, the delicate water balance in Colorado limits the water available for long-term storage from fractions to a few inches per year. Given these low recharge rates, it is readily seen why ground-water resources should be considered a finite resource.

Thunderstorms on the eastern plains, while typically intense,
provide little recharge to ground water.

Figure 1.3 Average annual water balance in Colorado.
(Click image to zoom 0.7MB)

Chapter 1, Page 3 of 4





			Chapter 1, Page 3 of 4 Climate and Water An area’s climatic conditions will ultimately control its ground-water resources because the source of ground water is infiltration of precipitation. Colorado’s location, far inland from any ocean, and its variable topography greatly influence weather patterns producing a semiarid climate with hot summers and cold winters. These climatic conditions produce a mean annual statewide precipitation of 17 inches. On average, 81 percent of the precipitation that falls on the land surface is lost through evapotranspiration producing a water balance deficit over most of the state, with the exception of the higher mountainous regions (Figure 1.3). While the amount of water recharged to a local aquifer is dependent upon climatic conditions, land surface characteristics, and aquifer hydraulic parameters, the delicate water balance in Colorado limits the water available for long-term storage from fractions to a few inches per year. Given these low recharge rates, it is readily seen why ground-water resources should be considered a finite resource. Thunderstorms on the eastern plains, while typically intense, provide little recharge to ground water. Figure 1.3 Average annual water balance in Colorado. (Click image to zoom 0.7MB) Chapter 1, Page 3 of 4