What Is the Future of ASR in the Denver Basin Aquifers?

The Denver Basin covers an area of 6,700 square miles and there is a large volume of underground storage available. The allure of this storage is the lack of evaporative loss, compared to surface water storage. The future of ASR is dependent on future conditions and use of water in the Denver Basin aquifers. These aquifers have historically been the primary water supply for communities along the Front Range. Initial ASR research focused on providing a regional supplemental water supply using excess surface water in wet years as the source water for injection. With the aquifers all in a confined state, the benefits from injection could be felt regionally through increases in aquifer pressure. However, aquifer use is now evolving because of significant water level declines, with water levels dropping below the top of the aquifers in many locations. This situation has resulted in a growing concern over the lack of sustainability of Denver Basin water supplies and, therefore, the need to find either supplemental or replacement water supplies. These supplies would likely be trans-basin diversions of renewable water supplies that can not only replace current primary Denver Basin aquifer water supplies, but also become a future source for excess surface water supplies by becoming the source water for ASR. Therefore, as Denver Basin aquifer use evolves, ASR’s potential role with respect to Denver Basin aquifer water supply needs to evolve as well. As Denver Basin aquifer use will not cease completely, due to drought protection, ASR could have a role in the future. This role will likely be through local application to provide supplemental storage and to improve local water levels and well production rates. The question is: What can ASR’s measurable impact be to future water supplies and management strategies for a growing Denver metropolitan area?