New Colorado River rules are in effect. What does that mean for Yuma?

Federal water reductions begin in 2027, but Yuma's farms, irrigation districts and households don't all have the same water rights. The biggest question is still how the new rules will affect local deliveries.

By Dan Bustard | Yuma Informed

October 1 marked the beginning of a new chapter for the Colorado River. It did not, however, mean that every farm, irrigation district and household in Yuma County suddenly lost a portion of its water.

That distinction has been getting lost in the discussion over the federal government's new operating rules.

The rules are real. So are the reductions they require. Beginning January 1, 2027, the three Lower Basin states must reduce their combined annual consumptive use of Colorado River water by 1.25 million acre-feet.

But figuring out how those reductions reach individual water users is another matter.

Arizona, California and Nevada were still working out the details when the new rules took effect. And for Yuma, where water rights can differ considerably from those serving Phoenix and Tucson, a statewide reduction doesn't automatically translate into the same percentage cut for everyone.

The federal decision is final. Its full local consequences are not.

October 1 changed the rules, not everyone's water deliveries

Interior Secretary Doug Burgum signed the new Colorado River operating guidelines on August 21.

The decision came after years of negotiations among the seven Colorado River Basin states failed to produce a long-term agreement. With reservoir levels falling and existing operating arrangements expiring, federal officials moved forward without that consensus.

The result is a 10-year framework extending through 2036, with more specific rules generally developed in two-year periods. The first covers 2027 and 2028.

There are also two different calendars involved.

Lake Powell operates on a federal water year beginning October 1 and ending September 30. Lake Mead's annual water-delivery decisions for the Lower Basin follow the regular calendar, January through December.

That means the new operating framework began October 1, 2026, while its larger Lower Basin reductions apply beginning January 1, 2027.

The difference matters when trying to determine whether a change in federal reservoir operations has actually changed a local water delivery.

At Lake Powell, federal officials expect to release between 6 million and 7 million acre-feet during water year 2027. Reclamation's September 24-Month Study places the reservoir in its Low Elevation Infrastructure Protection Range, where operations are designed to protect Glen Canyon Dam.

The release amount may change as conditions develop. Interior expects to determine the water-year release volume in April 2027.

Those decisions affect how much water moves between the major reservoirs. They do not, by themselves, tell a Yuma farmer how much water will be available through an irrigation district.

Arizona faces a major reduction, but the final details matter

Under the 2027–2028 operating guidelines, the Lower Basin's annual consumptive-use allocation falls from the normal 7.5 million acre-feet to 6.25 million.

An acre-foot is roughly 326,000 gallons. The federal reduction amounts to approximately 407 billion gallons annually.

Consumptive use refers to water that is consumed rather than returned to the river. It is different from the total amount diverted into canals or municipal water systems.

If the Lower Basin states complete the necessary implementing agreements, the reductions would be divided this way:

StateAnnual reductionRemaining allocation

Arizona

760,000 acre-feet

2.04 million

California

440,000 acre-feet

3.96 million

Nevada

50,000 acre-feet

250,000

Total

1.25 million

6.25 million

Those figures are written into the federal guidelines, but their distribution depends on the agreements being completed.

Without fully executed agreements, the Interior secretary must determine how the available water is apportioned under applicable law.

That's a considerable detail to leave unresolved with January approaching.

On October 1, KJZZ reported that negotiations were continuing. Arizona Department of Water Resources Director Tom Buschatzke said Arizona and Nevada had plans in place, while California was still working through details involving major water users.

Buschatzke was optimistic that agreement language could be ready for consideration by participating boards within weeks. That was his expectation, not confirmation that the agreements had been signed.

Arizona also faces a separate legal requirement.

Under A.R.S. § 45-106, an agreement entered into by the state's water-resources director involving Arizona's sovereign rights or claims is ineffective without legislative approval through a concurrent resolution.

That could require a special legislative session.

The public materials reviewed through October 8 did not establish a fully executed Lower Basin implementing agreement or a scheduled date for the necessary Arizona legislative action.

Why Yuma isn't the same as Phoenix

Much of the statewide discussion focuses on the Central Arizona Project, the canal system that delivers Colorado River water to central and southern Arizona.

Yuma's water arrangements are different.

Local farms and irrigation districts receive water through longstanding federal project arrangements, contracts and water rights. The Yuma Project, for example, uses infrastructure associated with Imperial Dam and the All-American Canal.

The differences go beyond which canal carries the water.

Colorado River entitlements are organized by priority. Some rights are senior to others, meaning they generally stand ahead of lower-priority users when shortages are distributed under the governing legal arrangements.

Reclamation's August 2024 entitlement records place several Yuma-area suppliers in the third priority, including Wellton-Mohawk Irrigation and Drainage District, the City of Yuma and the Yuma Mesa Division.

The Yuma Mesa entitlement is shared among North Gila Valley Irrigation District, Yuma Irrigation District and Yuma Mesa Irrigation and Drainage District.

Some local water users also hold present perfected rights, which occupy the first priority.

The Central Arizona Project, meanwhile, is listed in the fourth priority, alongside other fourth-priority users. Reclamation's Arizona priority rules explain how those rights are treated.

That is why simply applying Arizona's proposed statewide reduction percentage to every Yuma water user would produce a misleading answer.

It would be equally misleading to conclude that senior rights guarantee no local changes.

Federal operating decisions, annual water orders, the treatment of other priority holders and voluntary conservation agreements can all affect the final picture.

A legal entitlement establishes an important right. It is not the same document as an approved annual delivery.

Yuma Informed previously examined those differences in Arizona Is Losing Colorado River Water. Is Yuma?.

What Yuma's current water records actually show

The latest local numbers offer some perspective, although they describe 2026 rather than next year's deliveries.

Reclamation's October 8 forecast of 2026 water use lists the City of Yuma with an approved annual diversion of 32,600 acre-feet.

The report forecasts a diversion of approximately 30,806 acre-feet and consumptive use of approximately 18,107 acre-feet.

Those figures describe different things. The approved diversion is the amount authorized for the year, the forecast diversion is the amount expected to be taken from the river, and consumptive use accounts for water consumed rather than returned.

None of those numbers is a final 2027 delivery authorization.

The same federal report estimates 23,901 acre-feet of system conservation associated with Yuma Mesa Irrigation and Drainage District under an existing conservation agreement.

That conservation activity matters. It demonstrates that local water users are already participating in efforts to reduce pressure on the river system.

But it is not evidence that a new mandatory cut was imposed on the district October 1. Nor does the forecast establish the district's final conservation savings or payments.

Wellton-Mohawk has also addressed the changing federal rules.

In an undated statement responding to the July 31 environmental review, still posted October 8, the district said no immediate delivery changes were being announced.

It also described the proposed 2027–2028 guidelines as avoiding uncompensated, out-of-priority reductions for Yuma-area water users.

That was the district's assessment of the July proposal. It should not be mistaken for a final delivery schedule under the rules adopted in August.

The City of Yuma's water-conservation information similarly explains that the City is not currently subject to Central Arizona Project reductions. Its published guidance, however, addresses the 2026 shortage rather than a completed municipal response to the new 2027 rules.

As of the October 8 review, the available records did not establish a new citywide water restriction, a water-rate increase, a specific loss of farmland or a quantified local economic loss caused by the October transition.

That doesn't settle what might happen next. It establishes what the documents currently support.

Lake Mead shows why federal officials are worried

The uncertainty over local deliveries should not obscure the condition of the river itself.

Lake Powell and Lake Mead have been struggling under prolonged drought, declining runoff and heavy demand. The federal government adopted the new framework partly because the existing arrangements were no longer sufficient to address the risks facing the reservoirs and their infrastructure.

On October 7, Reclamation's provisional measurements placed Lake Mead at approximately 1,037.7 feet above sea level.

What happens next depends heavily on inflows, releases and conservation.

The September federal forecasts illustrate how much conditions can differ even under the agency's most-probable inflow assumptions.

With a 6-million-acre-foot release from Lake Powell, Reclamation projects Lake Mead could fall to 1,007.38 feet by the end of July 2027.

Under a 7-million-acre-foot release scenario, the projected elevation for that same month is 1,018.11 feet.

That's a difference of more than 10 feet at Lake Mead.

These are modeled scenarios, not guaranteed outcomes. Actual reservoir conditions will depend on weather, runoff, operating decisions and other factors.

The new guidelines also contain a warning threshold.

If Reclamation's most-probable forecast shows Lake Mead falling below 1,010 feet at any point during the following 12 months, federal officials must consult with the Basin states, tribes and other affected parties about possible additional actions.

That threshold triggers consultation. It does not automatically impose a particular water reduction on Yuma.

The rules also call for an additional 700,000 acre-feet of voluntary Lower Basin conservation across 2026, 2027 and 2028 combined, beyond the annual 1.25-million-acre-foot reductions planned for 2027 and 2028.

How those conservation commitments are carried out will depend on further agreements with water users.

Yuma is already preparing for a possible legal fight

The City of Yuma has not been waiting quietly for the federal process to play out.

On September 16, the City Council authorized the City Attorney's Office to explore potential legal action concerning the federal government's new Colorado River operating decision.

That authorization allows the City to consider legal options, retain counsel and potentially pursue litigation to protect its water entitlement rights.

It does not establish that a lawsuit has been filed.

The Council also approved a separate action involving an existing federal judgment in a proposed water-transfer case. The two matters involve different legal questions.

Yuma Informed covered both decisions in Yuma Authorized Two Colorado River Legal Actions. They Are Not the Same Thing.

The City's willingness to consider litigation shows how seriously it regards the federal changes, even as the effect on its own future deliveries remains unresolved.

What to watch before January 1

The next important decisions will come from agreements, approvals and water-delivery records, rather than from the calendar alone.

The Lower Basin states still need to complete the arrangements necessary to implement their proposed distribution of reductions. Arizona must address its legislative approval requirements where applicable.

Reclamation's 2027 Annual Operating Plan, which was still being developed when the September study was issued, will provide another part of the federal picture.

For Yuma's farms and irrigation districts, the more immediate documents will be their individual 2027 water orders, approved delivery schedules and any new conservation commitments.

The federal rules also require work on the next round of operating guidelines to begin no later than October 1, 2027, with consultation involving the Basin states, tribes and other affected parties.

This review did not obtain final 2027 delivery notices for every Yuma-area supplier or new interviews with local water officials. Some district websites were inaccessible during the review.

So the question isn't whether the Colorado River faces serious reductions. The federal government has already made that decision for the Lower Basin.

The unanswered question is how those reductions, along with the agreements still being negotiated, will affect the particular rights and deliveries that Yuma depends on.

For a grower, that answer will ultimately come through the water available under the farm's irrigation district arrangements. For a household, it will come through any changes announced by the municipal water supplier.

Until those decisions are documented, claiming that Yuma has escaped the cuts entirely would be premature.

So would claiming that everyone here is about to lose the same percentage of water.

The river operates under new rules. Yuma is still waiting for the details that matter most locally.

Follow Yuma Informed's Colorado River Water & Yuma coverage for the underlying records, local water-rights information and developments as the 2027 decisions take shape.