The practice of Aquifer Storage and Recovery (ASR) has been successfully implemented at the local level in Colorado for decades, but there are advantages to coordinating underground storage at a regional level. SMWSA is conducting a study to evaluate the feasibility, economic constraints, and benefits of a regional ASR project. Working with entities such as Denver Water, Centennial Water & Sanitation District, and Aurora Water, South Metro Water is leading the efforts to regionalize ASR.
A critical component to securing our water future is storage. As we pursue surface water storage such as the Chatfield Reallocation Project and Rueter-Hess Reservoir, we are also pursuing the implementation of underground storage through ASR within the South Metro area.
ASR is the storage of water in a suitable aquifer through direct injection in a well when water is available and later recovery of the water from the same well when it is needed.
ASR has been successfully implemented in portions of the Denver Basin for more than 20 years. South Metro Water and several of our members are actively exploring options to broaden this practice to store renewable water during times when it is available for later use in years of drought. Some advantages of ASR compared to traditional surface storage in reservoirs include: reduced infrastructure and permitting costs, lower evaporation loss and, typically, greater public acceptance.
Given our success implementing ASR at the local level, and the fact that renewable water supplies are becoming available to the South Metro area through the WISE project, the Chatfield Reallocation and other projects, South Metro entities are in a unique position to execute local and regional ASR. A large-scale conjunctive use plan, with the help of a regional ASR program, can change the use of the Denver Basin aquifer system from an unsustainable base supply to a secure and sustainable drought supply.
Building on the success that Centennial Water has had with ASR, several other South Metro entities are pursuing pilot projects to test how ASR would work with specific renewable water supplies in specific wells within their service area. East Cherry Creek Valley Water and Sanitation District (ECCV), the Town of Castle Rock, Rangeview Metropolitan District, Meridian Metropolitan District, and Pinery Water and Wastewater District are studying and pilot-testing and have plans to incrementally expand ASR within their existing well fields.
For its part, the South Metro Water is conducting a regional ASR pilot project with financial assistance from the Colorado Water Conservation Board. This study will not perform any physical injection of water into an ASR well, but it will evaluate the technical, financial, and logistical hurdles that prevent a water provider that has ASR capabilities from storing water for another provider that may not be able to perform ASR for itself.
Whether implemented individually by South Metro entities or as part of a regional ASR program, there is great potential for ASR in the Denver Basin Aquifer system. South Metro Water estimates that existing well fields may have more than 100 million gallons per day (MGD) of capacity available for ASR without dramatically impacting current well field operations. As renewable water supplies come into the South Metro area, ASR can play a significant role in creating a secure and sustainable water supply for the region.