The river that helps fill Oro Valley’s taps is having its worst year in decades. Federal data now shows 2026 could produce some of the lowest water levels ever recorded on the Colorado River system, and Oro Valley’s water utility is already preparing for the fallout.
A river running out of snow
Most of the Colorado River’s water starts as snow in the Rocky Mountains. This past winter, that snowpack came in at roughly half its normal amount, following the warmest winter on record across much of the West. Less snow means less spring runoff, and this year’s runoff into Lake Powell, the river’s key upstream reservoir, has been tracking at some of the lowest percentages of average ever measured.
The numbers from the U.S. Bureau of Reclamation, the federal agency that manages the river’s dams, tell the story plainly. Inflow into Lake Powell this spring ran as low as 7 percent of the 30-year average in June, and the broader water-year forecast sits at about a third of normal. Lake Powell and Lake Mead together hold roughly 80 percent of the entire river system’s storage, and both are now projected to approach or beat their all-time low water marks. Lake Mead could fall to around 1,040 feet by July, matching the record low first set in 2022, with federal models showing it could drop even further, into the low 1,020s, within the next year or two.
This isn’t just one bad winter. Scientists studying the basin describe a shift from ordinary drought into something more permanent, a hotter, drier climate pattern some now call “aridification.” Since 2000, the river’s flow has shrunk by about 20 percent compared to 20th-century averages, and the gap between what the river provides and what the Southwest has come to depend on keeps widening.
The consequences reach far beyond the riverbank. The Colorado supplies water to roughly 40 million people across seven states and Mexico, along with millions of acres of farmland and hydropower systems that keep the lights on from Denver to Las Vegas. Lower reservoir levels also mean less hydroelectric capacity at dams like Hoover and Glen Canyon, a problem utilities across the region are now factoring into their own planning.
What this means for Arizona
Arizona takes its share of Colorado River water through the Central Arizona Project, the 336-mile canal system that carries water from the river across the state to cities like Tucson and Phoenix. Because Arizona holds junior water rights compared to California, it tends to absorb the earliest and steepest cuts when the river runs short. The state is already operating under a Level 1 Shortage Condition for 2026, which requires Arizona to give up roughly 512,000 acre-feet, about 18 percent of its normal allocation.
Federal officials and the seven basin states are now negotiating new long-term operating rules to replace guidelines that expire at the end of this year. Those talks haven’t produced a final agreement yet, and some states have floated the possibility of litigation if a deal doesn’t come together this year.
How Oro Valley is responding
Locally, the Town’s Water Utility has been paying close attention. Water Utility Director Peter Abraham told the Town Council in early June that Oro Valley has been informally told to prepare for a roughly 20 percent cut to its CAP allocation starting in January 2027. Nothing is finalized yet. The Bureau of Reclamation still has to confirm the number, and Abraham noted it could land higher or lower than 20 percent once it’s official.
Even so, Abraham struck a measured tone with the Council, telling members the town is in a strong position compared to many of its neighbors. His reasoning comes down to how Oro Valley built its water portfolio over the past two decades.
The town draws water from three sources: groundwater wells, CAP water delivered from the Colorado River, and reclaimed water used mainly for irrigation. CAP deliveries have made up around 27 to 28 percent of the Utility’s total water production in recent years, with groundwater covering most of the rest. That balance is deliberate. Since Oro Valley began taking CAP deliveries in 2012, the town has cut its groundwater pumping by more than half, banking the savings as long-term aquifer credit it can draw on later.
That stored credit is a big part of why officials aren’t sounding alarms. The town holds an annual CAP entitlement of 10,305 acre-feet and has accumulated tens of thousands of acre-feet in long-term storage credits at recharge facilities, plus a membership in the Arizona Water Banking Authority that gives it access to additional stored CAP water if deliveries get cut. Abraham used 2025 numbers to walk the Council through a worst-case scenario: even with a 20 percent CAP reduction, the town would only need to pump about 11 percent more groundwater than it already does to make up the difference.
The town is also investing in new infrastructure. The Northwest Recharge, Recovery, Delivery System, expected to come online around 2027, will let Oro Valley draw up to 4,000 additional acre-feet of CAP water each year, on top of what it already receives. Once complete, it’s expected to further reduce the town’s reliance on groundwater pumping even as Oro Valley continues to grow.
“We are in a state of crisis,” Abraham told KGUN9. “We need to act now so we’re not in a state of emergency in the future.” He was quick to add that residents shouldn’t expect any disruption when they turn on the tap, now or for decades to come.
Sidebar: What a Water Right Actually Means
Oro Valley’s CAP entitlement and its relatively mild 20 percent cut estimate raise a question worth spelling out. What does it actually mean to hold a “right” to a set number of acre-feet, if the people managing the river can cut deliveries anyway?
The short answer is that a CAP entitlement is a priority ranking, not a guaranteed volume of water. CAP water is allocated through a tiered system, from highest to lowest priority: Indian priority, municipal and industrial (M&I), non-Indian agricultural, and various lower-tier “excess” pools. When the river doesn’t produce enough water to fill every entitlement, cuts start at the bottom of that list. Since 2020, CAP’s mandatory reductions have wiped out the excess and agricultural pools first, while trimming only a small amount from the M&I and tribal pools.
Oro Valley holds M&I priority, which is why a 20 percent cut sounds manageable next to what agricultural users have already absorbed. But that protection comes from where the town sits in the priority order, not from any physical guarantee that the water exists. The Bureau of Reclamation controls actual releases from Lake Powell and Lake Mead, and an entitlement on paper doesn’t create water that isn’t in the reservoir. Water managers call this the difference between “paper water,” the legal right, and “wet water,” the water that’s actually available to deliver.
This is also why Oro Valley’s banked storage credits matter so much. A right to future CAP deliveries can be curtailed. Water already stored underground through the Arizona Water Banking Authority cannot, since it’s physically in the aquifer rather than a claim on a river that may or may not deliver. The priority system determines who gets cut first among existing users. It doesn’t obligate anyone to produce water that the river simply doesn’t have. If Colorado River inflows keep falling in the years ahead, even M&I priority holders could eventually see real cuts, not just the pools below them.
The bigger picture
Oro Valley’s planning doesn’t erase the seriousness of what’s happening upstream. The Colorado River Basin is confronting conditions unlike anything in the historical record, and the decisions being made this year, both in Washington and among the seven basin states, will shape how much water reaches Arizona for years to come. For now, the Town’s groundwater savings account and its diversified supply give Oro Valley a cushion that many CAP-dependent communities don’t have. Whether that cushion holds will depend on how deep the cuts eventually go, and how quickly the basin states can agree on a shared plan for a shrinking river.
Sources: U.S. Bureau of Reclamation 24-Month Study and Colorado River operations data; ABC News; KTNV Las Vegas; EarthSky; National Geographic; Sierra Club; KGUN9; Tucson Local Media; Oro Valley Water Utility Annual Reports and Water Utility Commission records.
