THE SUSTAINABLE WATER SUPPLY DEFICIT IN THE SOUTH METROPOLITAN DENVER AREA

The southern suburbs of the Denver, Colorado metropolitan area have one of the highest average growth rates in the United States. Arapahoe and Douglas Counties, two of the major growth areas in the region experience a 45% increase in population from 1990 to 2000. Douglas County experienced a 185% increase in population. During the 1990’s, the two county population grew by approximately 209,000 persons. The population is expected to increase by an additional 442,000 persons during by 2030.

Much of the new growth in the area depends on groundwater derived from the Denver basin aquifer system. Groundwater reserves in the aquifer system are naturally non-renewable resulting in declining water levels within several municipal use areas. More importantly, continued development is creating a sustainable water supply deficit which is projected to increase from approximately 19,000 Acre-Feet per Year (AF/Yr) in 2000 to 107,000 AF/Yr by 2030 unless additional sustainable water reserves are developed. The annual tracking of the sustainable water supply deficit for the area is an important tool for water resource managers interested in the management of the Denver basin aquifers in the area as a long-term water supply.