John Moore, a retired deputy assistant chief hydrologist and field scientist with the U.S. Geological Survey, spoke to the citizens’ group Protect Our Wells (POW) in August. Moore has worked as a technical advisor to the U.S. Department of Agriculture and the U.S. House of Representatives and currently teaches short courses in hydrology.The focus of his presentation was on ground water, the primary source of water for the Denver and Colorado Springs area. The 6,700-square-mile Denver Basin, which consists of several aquifers, has experienced depleted water levels as growth in the area intensifies.”Ground water availability is a major issue in Western states, where we have a limited amount of surface water,” Moore said. “Most of the water supply for this area, now and in the future, is ground water.”POW, also known as the Denver Basin Aquifer Private Well Owners’ Association, currently has about 250 members. The group advocates for private well owners and gathers information about Denver Basin ground water supplies.Moore presented a series of slides that included maps of the basin and data on ground water use. “Some people have the philosophy that the way to get around this water shortage is to drill another well,” he said. “The more wells you have, the more they interfere and the more the costs go up for lifting the water. This gets expensive.”In many areas in Denver, such as Parker and Highlands Ranch, ground water is being pumped from the confined aquifer and streams are being depleted, he said. “Homeowners in Highlands Ranch are probably not going to make it to the end of their home loan without running out of water,” Moore said. “Probably what will happen is they’ll increase the cost of the water.”The situation in the Falcon/Black Forest area is not yet as critical as in the Denver area. The aquifers in this area are unconfined, which means there is no confining bed between the aquifer and the land surface. “So, you’re not pumping large amounts of ground water, and it’s replenished in most years,” Moore said.The 100-year standard established by the state in 1973 allows well owners to only pump 1 percent of the estimated available water per year. Since water estimates are always uncertain, the well may or may not last 100 years. “I asked a state legislator how they came up with 100 years, and he said, ‘Because I’ll be dead then!'” Moore said. “Since the Denver Aquifer is geologically complex, you might get a 100-year life at one well, but if you move over 100 feet, you’ll get 20 years or 10 years.”The impact of growth on water levels is difficult to determine. “Denver population has doubled from 1.2 million in 1960 to 2.2. million in 2005,” Moore said. The population of El Paso County has seen a four-fold increase in roughly the same time frame, from 144,000 in 1960 to an estimated 576,000 in 2006.The only way to determine how much water this area has available is to monitor water levels in wells. “You need to set up observation wells in the Dawson,” he said. “Existing wells could be used, and then water levels are measured approximately twice a year.” He suggested that POW members approach the county government with a proposal to share the costs for such a project. “The state is going to leave it up to you,” he said.The meeting concluded with POW president Sandy Martin urging attendees to join the group or renew their current memberships. “More members bring more credibility,” she said. “Private well owners do not have water resources to fall back on when their wells run dry.”
