Central Avra Valley Storage and Recovery Project (CAVSARP) - History

Purpose and History

CAVSARP allows Tucson Water to efficiently use Colorado River water as a drinking water supply through a process known as recharge and recovery. Groundwater overuse in the latter half of the 20th Century led to severely declining groundwater levels and the beginnings of subsidence (land sinking) in and around the Tucson area. In addition, Arizona law requires Tucson and other groundwater-dependent communities to reduce reliance on this limited resource and concentrate on using renewable water supplies.

To eliminate over-pumping and mitigate past over-use, the City has been transitioning from groundwater to renewable Colorado River water, delivered via the Central Arizona Project (CAP). Water quality issues that occurred when Colorado River water was first delivered to Tucson Water customers in 1992-94 led to the passage of Proposition 200: the Water Consumer Protection Act, which prevents delivery of CAP water directly to customers. To meet the requirements of the Act, Tucson Water developed CAVSARP to recharge, store and recover a blend of Colorado River water and native groundwater. This allowed the City to shut down many of its groundwater wells serving urban Tucson.