Arizona’s Groundwater Replenishment Program Facing an Uncertain Future

PHOENIX — A key water management tool that sustains housing development in central Arizona does not have a rosy future, according to a new report from Arizona State University.

The report looks at the Central Arizona Groundwater Replenishment District, which the Legislature established in 1993 to assure the replenishment of groundwater that’s tapped for development.

Developers and, by extension, home buyers, can pump and purchase groundwater and then pay into the program; the district then has to replenish the water that serves those homes. This is a way to meet the state’s water management goals and comply with the legally required 100-year water supply.

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But the report outlines several concerns about the specific rules that govern the replenishment district and casts doubt on the district’s ability to find water to meet expected obligations.

One concern is that the replenished water does not have to be returned to the same place where it originally was pumped. The district only has to put water back into the larger active management area, and the recharged water doesn’t necessarily migrate to where it’s needed.

“It’s an unsustainable practice,” said Kathy Ferris with ASU’s Kyl Center for Water Policy, the report’s co-author. “There are so many different aquifers and layers. There are seven subbasins. And water doesn’t just move around like it’s in a bathtub. Sometimes it doesn’t move at all, depending on where it’s recharged.”

There are five active management areas in central Arizona. The one in Phoenix, for example, covers 5,646 square miles.

Another concern is financial. As water in Arizona becomes more expensive, some homeowners enrolled in the replenishment district have looked for water that’s cheaper than the original source the developer identified for its required 100-year water supply. A different source may free homeowners from paying an annual charge for replenishment.

The problem, the report said, is that the district still must find and pay for water “to meet the member’s long-term replenishment obligation.”

Depending on how many homeowners use this cheaper-source strategy, it could mean consistent expenses but lower revenues for the replenishment district, which has fixed costs that do not fluctuate depending on how much water needs to be replenished that year.

Ferris cited a consultant’s report from 2017 that said if all of the Phoenix area lands enrolled in the replenishment district used this workaround, the result would be “financially catastrophic.” The consultant’s policy recommendations involved legal or regulatory changes that have not been enacted.

The ASU report also raises concerns over the amount of water the replenishment district is expected to need to meet its current and projected obligations, especially at a time of shortage conditions on the Colorado River, the state’s largest source of surface water.

The district’s board also runs the Central Arizona Project canal system. In a statement, the agency pointed out it “was charged with the statutory obligation to manage the CAGRD since its inception more than 25 years ago,” saying it “has fulfilled this duty effectively, demonstrating fiscal responsibility while securing a robust water supply portfolio that will be available through the mid-2030s.”

CAP also acknowledged in the statement that its part of the discussion over where growth will happen in urban areas especially Maricopa County.

“CAP welcomes the opportunity to be part of it, but given that the focus of this conversation would be beyond CAP’s CAGRD responsibilities, CAP may not be the appropriate entity to convene and lead this conversation.”

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The agency does not have the legal authority to reject new enrollees in the groundwater replenishment program. The Arizona Department of Water Resources does have some oversight because it approves a 10-year plan for the district and can later reverse an approval.

But the report said “such a decision will be politically difficult, will not stop the sale of previously enrolled but unconstructed lots, and will not address CAGRD’s continuing replenishment obligations for its current members.” It recommends authorizing the program to deny accepting new members if needed.

A spokeswoman at the water resources department declined to comment on the ASU report, saying it had not yet been reviewed.

The report comes on the heels of the state releasing its own water bombshell: a new model for the Pinal Active Management Area that shows an expected shortfall of more than 8 million acre-feet of water. An acre-foot is enough water to cover 1 acre of land with 1 foot of water, enough to supply a family of four for a year.

“I think that the Pinal situation demonstrates that as time has gone on, we’ve learned more and more about our groundwater resources,” Ferris said. “And our scientific ways of assessing how much groundwater is there have dramatically changed. Nobody’s talking about the fact that, well, even if there was enough groundwater, if it’s all used up, it gets all used up.

“Then what?”

Unquenchable Thirst: Groundwater Bill Could Shift California’s Water Management Approach

LOS ANGELES – The latest salvo is California’s long-running water wars, SB307, has the potential to emerge as one of the most important pieces of water regulation in recent years. Although its target was narrow — it was designed to undercut the capacity of Cadiz, Inc. to pump annually upwards of 16 billion gallons of groundwater in eastern San Bernardino County and sell it to ever-thirsty Southern California — the legislation may prove to be far-reaching in its consequences.

Governor Gavin Newsom signed the bill into law on July 31, requiring independent review from the State Lands Commission, Department of Fish and Wildlife and the Department of Water Resources to ensure that pumping from the groundwater basin doesn’t harm the natural or cultural resources at the site and in the surrounding watersheds. Focused on short-term impact, columnist at the Desert Sun, decried the bill as a job-killer and legislative overreach. The Los Angeles Times and the Sacramento Bee read the law as yet another Golden State rebuke of the Trump administration and made much of the legislation’s protection of imperiled Mojave Desert springs and species. The environmental impact of the law was a point that Sen. Dianne Feinstein confirmed: “If Cadiz were allowed to drain a vital desert aquifer,“ she declared, “everything that makes our desert special — from bighorn sheep and desert tortoises to Joshua trees and breathtaking wildflower blooms—would have been endangered.“

Bighorn sheep relax along the Barker Dam trail in Joshua Tree National Park. (Photo via Jasperdo/Creative Commons)

These are all important considerations to be sure. But the new law is actually more expansive in reality and reach. Although the enduring battle over the control and distribution of white gold dates back to the Spanish conquest of Alta California in the late 18th century, this particular piece of 21st century legislation offers an important twist in the state’s longstanding struggle to secure a sustainable supply of this most-essential resource.

In this case, the play has been for desert groundwater. That unusual wellspring is a bit of a shock, not least because ever since the Gold Rush it has been Sierran snowmelt that has dominated the state’s mirage-like fantasies of an unending stream of water that would blast open mineral riches, fill reservoirs, irrigate farms and lawns, drive industrial production, and wash windows, cars, and sidewalks. This natural tap would forever boom the state’s economy. But could the desert, specifically the Mojave Desert, one of the most arid regions on this blue planet, become a rich repository of water? That has seemed a contradiction in terms.

Adding to the confusion is that the main actors in this most-recent drama are not the usual suspects. This story isn’t about water grabs devised by big ag in the Central Valley. It isn’t about a scheming Metropolitan Water District (though it would surely benefit from the deal). Neither the City of Los Angeles nor the State of California, each of which in the past has diverted vast amounts of other region’s water for its own ends (and ticked off a lot of people in the process), are the creators of this particular narrative.

Taking center stage instead is a clutch of venture capitalists who have invested in the Cadiz Project, and whose investment has underwritten the purchase of 34,000 desert acres and associated water rights in San Bernardino County. Theirs is a supply-side operation, a tantalizing pool of water that has not yet been integrated into California’s highly complex water-market. Should it ever be so — and you can be certain that Cadiz will do everything in its power to make that happen, SB307 notwithstanding — then its privately owned groundwater will become a cash cow for Wall Street profiteers.

The latest salvo is California’s long-running water wars has the potential to emerge as one of the most important pieces of water regulation in recent years. (Getty Images)

Standing in their way is this new law, the promise of which is that it unflinchingly calls the question on water agencies and consumers: why are we still fixated on securing new supplies of hitherto unexploited water, by hook or by crook? Cadiz, after all, is one more shimmering proposal, in a long line of such illusions, that ever-dry Southern California can solve its water crises by pumping out the Owens River Valley, the Colorado River, or that trio of NorCal rivers, the Feather, Sacramento, or the San Joaquin. Absent this law, and the Mojave would be yet another victim of our unquenchable thirst.

The adoption of this law sheds light on a new approach to water management: the smartest, least expensive, and most efficient method of building a more water-resilient state is to tackle the demand side of the equation. That’s at the heart of an argument by Peter Gleick, president Emeritus of the Pacific Institute, in a 2018 article in the Proceedings of the National Academy of Sciences. In it, he probes the new water-management paradigm that he dubs the “soft water path,“ a refocusing on the “multiple benefits water provides, improving water use efficiency, integrating new technology for decentralized water sources, modernizing management systems, committing to ecological restoration, and adopting more effective economic approaches.“ By rigorous conservation we can do more with less.

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That prospect isn’t new. It has been demonstrated in the implementation and constant improvement of low-flow technologies that are required features in building codes across California. It was strikingly manifest, amid a punishing four-year drought, in the rapid decrease in urban water use following Gov. Jerry Brown’s April 2015 declaration of mandatory emergency restrictions to cut consumption by 25%. It is evident as well in Orange County’s highly successful groundwater replenishment operation — to date, the world’s largest — that captures and treats stormwater and effluent to the EPA’s highest standard for potable water; the project currently serves more than 500,000 people a year (with an expansion underway to increase its capacity to an estimated 850,00 consumers by 2020).

This system is making a critical contribution to the county’s ambition to become water independent by 2050, an ambition that the UCLA Institute of the Environment and Sustainability believes Los Angeles County could replicate. In its 2018 report, the center highlighted “potential pathways to a transformation of the city’s historical reliance on imported water to an integrated, green infrastructure, water management approach that provides water quality, supply, flood control, habitat, open space and other benefits.”

Although galvanizing policymakers, politicians, and taxpayers to invest in these proven, real-world outcomes will not be easy, UCLA researchers believe “the recent extreme drought on water supplies throughout California has created a new urgency to increase the city’s ability to provide a secure, resilient water supply through local sources.“ SB307 might accelerate that transition by helping break our bad habit of relying on Cadiz-like pipe dreams, which the late historian Norris Hundley argues in “The Great Thirst“ was “born of an earlier era when abundance encouraged abuse.“ If it does so, then it will mark a significant turning point in the state’s contentious water history.

This story is part of Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.

Elemental: Covering Sustainability is a multimedia collaboration between Cronkite News, Arizona PBS, KJZZ, KPCC, Rocky Mountain PBS and PBS SoCal.