The federal government is considering a framework to cut Colorado River water use in Arizona, California and Nevada by as much as 3 million acre-feet a year.

Though the move is supposed to protect Lake Mead — which is on a swift and perilous path downward — it also could dry up taps and idle prime farmland across Arizona, devastating communities across the state.

A diverse swath of cities and irrigation districts, to their credit, are working overtime to blunt the impact of these potential cuts. 

But there could be roadblocks.

The focus is on voluntary water deals

Let’s start with Yuma.

Five irrigation districts serve the area. They primarily serve farmers and rely on third-priority water, which is later in line for cuts than many users in central Arizona and Mohave County.

The separate Yuma County Water Users Association delivers water to farmers, cities and tribes that hold some of the most senior water rights in the state. 

There has long been fear that powerful central Arizona interests would use political force to take this water.

But — at least for now — the focus is on finding mutually beneficial deals to keep taps flowing in central Arizona without decimating critical agriculture production in Yuma. 

Phoenix and Tucson are creating a voluntary water-sharing network that would be open to anyone who wants to buy, sell or exchange water supplies. 

Some Yuma irrigation districts are considering participation.

Return flows complicate the picture

But how much water could they put on the table?

This is where it gets tricky.

Because Yuma lies in a river delta, a significant portion of the water farmers use makes its way back into the Colorado River.

The federal government created complex formulas decades ago to quantify this return flow so others could use it downstream. 

Central Arizona water users don’t have to make these calculations because they are far removed from the Colorado River. 

Whatever water they divert is what they consume. 

So, if central Arizona cities agree to leave 100 acre-feet of water in the river, they receive credit — and compensation — for the full 100 acre-feet.

Not so in Yuma.

If its five irrigation districts do the same, they would only receive credit for a fraction of what they save — though the exact figures vary by district because some have higher return flows than others.

For some, that simply won’t be economically feasible.

Yuma has other potential roadblocks

There are other potential issues:

  • Wellton-Mohawk Irrigation & Drainage District’s return flows already play a key role in salinity control agreements and water deliveries to Mexico.
  • If Yuma Irrigation District or North Gila Valley Irrigation and Drainage District agree to save water, those savings must flow to Yuma Mesa Irrigation & Drainage District first. It’s part of the baggage that comes with the three districts sharing a single water entitlement.
  • Unlike its irrigation district neighbors, Yuma County Water Users Association doesn’t hold the senior rights to the water it distributes — its shareholders and landowners do. That means any conservation deal would likely have to be negotiated with multiple parties.
  • Not to mention that any unused water in the area has historically flowed to the next lower-priority user — the Central Arizona Project, which delivers water to cities and tribes in metro Phoenix and Tucson.

It’s unclear how much latitude the federal government will give Yuma irrigation districts to deviate from these practices.

It’s also unclear how much water Yuma can realistically cut and still supply winter greens and vegetables for the nation.

It can only tap groundwater in some areas, and not for much water.

“It’s a delicate balance, given that the primary economic driver in Yuma is ag,” said Meghan Scott, who represents a handful of Yuma irrigation districts.

“People sometime see Yuma as the naysayer, but we’re not saying no to be difficult. Negotiations here are just a lot more complex.”

Mohave County could be zeroed out

Meanwhile, three hours north in Mohave County, Colorado River users are in a pickle.

They rely on fourth-priority water, same as the Central Arizona Project, which could be completely wiped out under a 3 million-acre feet cut.

But unlike Central Arizona Project subcontractors, farmers and cities in Mohave County have no other water source.

Tapping groundwater is off limits because the aquifer is shallow and hydrologically connected to the Colorado River.

Lake Havasu City and Bullhead City aren’t using their full entitlements. But they also have no ability to store that water underground or in Lake Mead.

Local water officials want more flexibility for the treated effluent they create.

“If we can use our effluent, we have more options,” said Jamie Kelley, general counsel for the Mohave County Water Authority. “But if we can’t use it to develop stored supplies, I don’t know what happens to us.”

These are big, complicated challenges. But they are not insurmountable.

Despite the animosity that has divided the Colorado River basin, the conversation in Arizona now is about pitching in to keep each other afloat.

The better we understand the roadblocks to this effort, the better we can work around them — and find the creative solutions necessary to protect livelihoods on and off the Colorado River. 


Joanna Allhands writes about water, land use and other issues important to the Arizona Farm Bureau. Reach her at joannaallhands@azfb.org.