Low water level is sending Oro Valley a warningOro Valley is not facing an immediate water shortage, but the weakening Colorado River system could reduce the Town’s future flexibility and increase water costs.
Lake Powell’s decline is becoming more serious
Lake Powell is again moving in the wrong direction. The Bureau of Reclamation projects that the reservoir will end the 2026 water year at about 22 percent of capacity. The expected inflow for the year is just 36 percent of average. The reservoir is not merely a recreation destination hundreds of miles from Oro Valley. It is one of the two major storage reservoirs supporting the Colorado River system and the Central Arizona Project water delivered to communities across central and southern Arizona.
CAP water changed Oro Valley’s water future
Oro Valley began receiving CAP water through the Tucson Water system in 2012. In 2023, the Water Utility purchased its full annual CAP entitlement of 10,305 acre-feet. Of that amount, 2,573 acre-feet were recovered and delivered through the potable water system, representing 27 percent of the utility’s total water production. Other CAP water was used to replace groundwater pumping or stored for future use. By the end of 2023, Oro Valley had accumulated an estimated 34,493 acre-feet of long-term storage credits. Credits are an accounting right, administered by the Arizona Department of Water Resources, that allows the Town to recover an equivalent amount of water from permitted wells when needed.
The present situation does not mean that Oro Valley residents are about to turn on their faucets and find no water. Arizona is operating under a Tier 1 Colorado River shortage, but the reductions have fallen primarily on agricultural and other lower-priority CAP users. Municipal and industrial users continue to receive most of their allocations. Oro Valley also has groundwater wells, reclaimed water, storage credits and an annual CAP entitlement of 10,305 acre-feet. That diversified portfolio gives the Town protection against a near-term interruption.
The first loss may be water stored for the future
The more immediate risk is not necessarily a reduction in water delivered to existing customers. It is a reduction in the CAP water that Oro Valley can recharge and save for later. Water Utility Director Peter Abraham told the Town Council in June that the utility was preparing for a possible 20 percent CAP allocation reduction. He said current customer deliveries could be maintained, but less unused CAP water would be available for storage. That would gradually reduce the reserve Oro Valley has built for future droughts, growth and emergencies.
NWRRDS improves delivery but does not create water
The Northwest Recharge, Recovery and Delivery System will strengthen Oro Valley’s ability to recover CAP water stored west of Tucson and move it into the Town’s water system. The regional project is expected to provide Oro Valley with capacity to recover and deliver as much as 4,000 additional acre-feet annually. That should reduce groundwater pumping and give the Town greater control over its water deliveries. NWRRDS does not create another source of water. It provides a better way to deliver CAP water, and CAP water still depends on the condition of the Colorado River.
Lake Powell is a warning, not an immediate crisis
Oro Valley has prepared better than many communities for water uncertainty. It has reduced groundwater dependence, accumulated storage credits and invested heavily in regional infrastructure. Still, Lake Powell’s decline cannot be dismissed as someone else’s problem. A smaller CAP allocation could mean less water stored for the future, greater reliance on groundwater and storage credits, and higher costs for purchasing, transporting and recovering renewable water. Oro Valley is not running out of water. However, the renewable supply on which the Town increasingly depends is becoming less certain and more expensive. That makes conservation, reclaimed-water expansion and careful growth planning just as important as ever.
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