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A trend that has been observed recently, is that the potato farmers in Closed Basin trade in old <br />center pivot systems for new systems. Used center pivot systems are purchased primarily by <br />alfalfa hay farmers south of the Rio Grande. Potato farming benefits greatly from the accurate <br />and automated technology available in new center-pivot systems. This allows alfalfa farms to <br />also get center-pivot technology at reduced prices that are feasible for this less lucrative but more <br />dependable crop. <br />Ralph Curtis has personally directed an effort to map and characterize the agricultural lands, <br />cropping and irrigation sources in portions of the Valley. This effort involves both aerial <br />photography and ASCS aerial slides, as well as visual inspection of the fields using part-time help <br />in the summer. <br />Historical Groundwater Hydrology and Practices <br />The increased groundwater pumping in the San Luis Valley has, for the most part, benefited <br />farmers, but has also raised concern and controversy. Until the advent of groundwater pumping, <br />farmers were largely at the mercy of each year's surface water hydrology. With groundwater <br />pumping, irrigation water is available even during the late season and to some extent in dry years <br />when surface water would be non-existent. However, this increasing reliance on groundwater has <br />generated concerns about groundwater mining in the Valley, in other words, pumping <br />groundwater at a rate greater than either natural or man-made processes replace it. <br />In 1970, the State Engineer stopped issuing new well permits for the non-Closed Basin aquifers <br />and the Closed Basin confined aquifer. In 1981, the State Engineer stopped issuing new well <br />permits for the Closed Basin unconfined aquifer. In the early 1990s, the AWDI case brought the <br />groundwater situation in the San Luis Valley to the forefront. <br />All the management efforts described above have not prevented groundwater mining from <br />occurring in certain locations in the Valley. For example, agricultural pumping in the northeast <br />quadrant of the extensively irrigated area north of the Rio Grande is causing water levels to drop <br />in some areas. East of the County Line Road, pumping for potato and grain agriculture is also <br />suspected to be mining groundwater. About 23,000 acres of agricultural land in the Valley is <br />being irrigated which do not have any surface water rights. Many farmers and residents of the <br />Valley have observed that many of the historically flowing springs around the perimeter of the <br />Valley have decreased in flow, leading to further speculation that confined aquifer groundwater <br />pumping is the cause of these diminished flows. <br />The controversy over groundwater pumping is being addressed by the RGWCD by funding <br />projects to monitor and study groundwater levels. <br />Comments and Concerns <br />None <br />Attachments <br />1. Closed Basin Division Information Map <br />2. Closed Basin Division Project Description <br />3. Closed Basin Division Act of Congress <br />4. Bureau of Reclamation Projects Map -Albuquerque Area Office <br />5. Rio Grande River Basin Irrigation Map <br />C:Acdss\RGWCD.doc Rio Grande Water Conservation District Interview May 10 -Page 4 of 4 <br />