EXAMPLES OF GROUNDWATER MINING-DENVER, TUCSON, CHICAGO, LAS VEGAS

There has been a large increase in groundwater use in the United States for irrigation and municipal supplies. The U.S. Geological Survey has noted that increased groundwater use mining is a significant issue in almost every state. The development of groundwater has led to declining water levels and artesian head in a number of states. In several areas groundwater levels have declined 91m (300 feet) or more in the past 10 years. Five case histories were selected where groundwater mining has had a major impact: Denver Colorado, Tucson Arizona, Chicago Illinois, Central Valley of California, and Las Vegas Nevada. In these areas groundwater mining has caused serious environmental and other problems as follows: 1. Stream flow depletion, 2. Land subsidence, 3. Saltwater intrusion, 4. Increased cost to deepen wells, 5. Increased costs to pump groundwater, 6. Decrease in well yield, 7. Drying up of shallow wells and springs, 8. Degradation of water quality