Laserfiche WebLink
however, as wells are mechanically incapable of completely <br />draining an aquifer and economic considerations (costs of <br />pumping) will limit actual recoverable amounts. <br />In 1987 and 1988 a deep test well was drilled in Castle <br />Pines, and in 1999 a similar well was drilled near the town <br />of Kiowa. These wells were drilled by public agencies to <br />further the existing knowledge of the geology and hydroge- <br />ology of the Denver Basin aquifer system. Both wells were <br />continuously cored throughout the aquifer sequence. <br />Aquifer properties ascertained from the Castle Pines and <br />Kiowa core holes suggest that the aquifers are very hetero- <br />geneous and vary significantly with distance from the source <br />area of the sediments comprising the aquifer. The new core <br />hole data suggests that the quantity of recoverable water <br />AQUIFERS of THE DENVER BASIN, COLORADO <br />Figure 2. Bedrock geology of the Denver Basin. <br />Modified from Denver Museum of Nature <br />and Science, 1999 <br />stored within the Denver Basin may be one -third less than <br />previously estimated by Senate Bill 5 (Table 2). <br />GROUNDWATER WITHDRAWALS <br />Groundwater withdrawals within the Denver Basin <br />aquifers have a long history. The USGS reported that during <br />1985, total withdrawals from the Denver Basin aquifers were <br />36,000 acre -ft from approximately 12,000 wells (Robson and <br />Banta, 1995)• During that year, 53% of the water was used <br />for public supply and 34% was used for agriculture. <br />As of February 2001, approximately 33,700 wells of <br />record have been completed in the sedimentary rock <br />149 The Rocky Mountain Association of Geologists <br />