This is the 45th in a weekly series celebrating Colorado Water 2012.
By CRAIG COTTEN
VALLEY — Water users in the Rio Grande Basin in Colorado are facing many challenges, both natural and man-made. The basin is also facing challenges not only in our area, but from farther away as well.
The Rio Grande is in the fourth year of below average streamflows. Other parts of Colorado are also in a severe drought this year, with some areas having a more severe single year drought than the San Luis Valley. However, much of Colorado had very good precipitation and streamflow last year which filled their reservoirs and aquifers. In fact, some areas in the northern part of the state had one of their best years ever last year in terms of precipitation and streamflow, while this basin languished in the midst of a multi-year drought. Since the extreme drought year of 2002, there have only been three years of above normal flow on the Rio Grande and only two years on the Conejos River. Some smaller streams around the valley have fared even worse, with only one year of above normal flows in the last ten.
The water levels in the San Luis Valley aquifers are dropping, and have been dropping, over the last several years. This drop is in response to the lower than normal recharge into the aquifers from the area rivers, streams, and ditches. After seeing modest gains during the years of 2007 to 2009, the unconfined aquifer is once again dropping substantially.
According to the aquifer study conducted by Davis Engineering, the unconfined aquifer in the West Central part of the San Luis Valley has lost nearly 500,000 acre-feet of water during the last three years. There is not a formal, comprehensive study of the confined aquifer throughout the Valley, but this aquifer is also seeing significant declines in the amount of artesian pressure. While it is not known exactly how much water is in the aquifers, it is obvious that the San Luis Valley cannot continue this drastic drop in the aquifers without severe long-term consequences.
In order to address the problem of injury to surface water users and the decline in the aquifers due to well pumping, the State Engineer is in the process of developing Rules and Regulations concerning the withdrawal of groundwater in Division 3. The State Engineer is being assisted in the development of these rules by a 55 member advisory committee made up primarily of area water users.
While these rules are not completed yet, we do know generally what they will require. In general, the rules will require that large capacity wells in the San Luis Valley repay the injury that they are causing to senior water rights, which are generally ditch and canal rights. In addition, the rules will have a sustainability component which will require that well owners ensure that the underground aquifers are brought back to a sustainable level.
The repayment of injurious depletions and ensuring sustainability can be accomplished by a well owner in two ways. A well owner may choose to implement an individual augmentation plan in which that owner will cover his individual well or wells. Otherwise, a well owner may choose to join a subdistrict, which, in exchange for monetary payment, will provide the repayment of injurious depletions and the sustainability of the aquifers for that owner.
After the rules and regulations are completed, nearly all large capacity wells in the San Luis Valley will be required to replace their depletions and sustain their aquifers, or they will not be allowed to pump. The large capacity wells that will be affected by these rules include not only irrigation wells but also municipal wells, some commercial wells, and other larger capacity wells.
In May of this year, the first subdistrict became active. Currently this subdistrict, covering wells in the central part of the Valley, is actively replacing water to the Rio Grande to offset the injurious depletions caused by well pumping. Also, this subdistrict has fallowed a large amount of farmland to attempt to bring the aquifer into a sustainable condition. However, there are still concerns by some over this subdistrict, and another trial over these issues was held last week.
Water users here in the San Luis Valley face many challenges, even some occurring hundreds of miles away. Even though Colorado is protected by the Rio Grande Compact, there are always groups and individuals looking to gain more water for their downstream uses. The State of Colorado and local water users are closely watching a large court battle between New Mexico and the Bureau of Reclamation regarding Rio Grande Compact issues. In fact, Colorado has briefed the judge in the case on some of the issues, although Colorado is not a party to the case. This case, and other similar court cases looming on the horizon, has the capacity to drag Colorado into a long, expensive battle in which other parties may seek to gain more of Colorado’s water from the Rio Grande and Conejos Rivers.
One of the other concerns on the Rio Grande is the issue of endangered species. The two main endangered species of concern on the Rio Grande are the Silvery Minnow and the Southwestern Willow Flycatcher. These two species depend upon streamflow in the Rio Grande for their survival, and the US Fish and Wildlife Service is actively engaged in developing new regulations for the protection of both of these species. Colorado is assisting the Fish and Wildlife Service in the development of these regulations to try to ensure that the species are recovered but that the regulations do not adversely affect water use in Colorado. As described in a previous article, the Rio Grande Compact protects Colorado water users from downstream water grabs that would seek to take more of our water for these downstream uses. However, there are groups downstream that are always scheming of ways to get more water from Colorado.
There is no magic bullet to solve all of the Valley’s water woes, but increased snowpack and streamflow will make a huge difference. With more flow in the rivers and streams, surface water users will have a higher supply of water for their crops and the underground aquifers will have a higher recharge rate that will help them to rebound from their recent drops. Also, higher streamflows in Colorado will translate into more water in the Rio Grande through New Mexico. This will help the endangered species and alleviate some of the concerns from downstream users about Colorado’s use of water. We don’t know what this winter will bring in terms of snowpack, but we are all hoping for a good year.
For more information on Water 2012 in the Rio Grande Basin, please visit www.water2012.org or www.rgwcei.org. This month’s Rio Grande Roundtable meeting has been canceled. The next meeting will be held on December 11.