Here’s a guest column written by Steve Vandiver that’s running in the Valley Courier. Here’s an excerpt:
Wells were constructed from the earliest days of settlement in the Valley; and in fact, the oldest appropriation of water in the San Luis Valley is a small domestic well in the Conejos area. No new non-domestic appropriations from the aquifers in the Valley have been allowed for 30 to 40 years depending on the aquifer and the area of the Valley being considered. The moratoriums on new wells occurred as a result of the State Engineer Office’s recognition that additional groundwater appropriations would cause impacts to those aquifers and surface streams…
Recent drought conditions, with the lowest water year being 2002, have caused significant reductions in the natural runoff that recharges this study area, and have greatly reduced the diversions from the Rio Grande that normally provide approximately 275,000 acre-feet of additional recharge into this area. Recharge into the aquifer from those diversions occurs through infiltration from the ditches and from constructed recharge pits that introduce water into the aquifer.
Aquifer storage continues to decline even though the irrigated area within the study area has been reduced by approximately 20,000 acres over the last 12 years and recently by additional thousands of acres placed in fallowing and preventative planting insurance programs.
Graphs of the unconfined aquifer storage study show the changes that are occurring in the unconfined aquifer and are indicative of the significant reductions in storage that have occurred from changes in the hydrologic conditions over the last decade. Well pumping in the area has been reduced by approximately 20 percent in 2012, over the last several years because of management efforts of the well owners themselves and efforts of Rio Grande Water Conservation District’s Subdistrict #1.