From The Arizona Daily Star (Tony Davis):
The total stored is nearly 3.6 million acre-feet of water in 28 sites across Pima, Pinal and Maricopa counties. That’s well over two years worth of CAP deliveries. They’ve stored another 600,000 acre-feet for Nevada.
The total tab has topped $330 million for the state and the Central Arizona Project to design and build storage basins and recharge water in them by artificial means.
But all that work has left a key detail unsettled: how to withdraw the bank’s water when needed.
No wells or other infrastructure exists to pump the water from recharge sites where nearly 25 percent of the water-bank water is stored, including one of the system’s largest recharge facilities. While water is also banked in some of the cotton, alfalfa and grain fields served by CAP water, and they do have infrastructure to get the water out, many of these facilities are far from urban and tribal users…
Tucson is better primed than most cities for water-bank recovery. The water bank has put more than two years worth of the city’s water needs into city-owned recharge basins in the Avra Valley, many miles west and northwest of the city limits.
City wells to pump that water out are already in place. But that’s mainly because Tucson Water’s original delivery of CAP water in the 1990s was so problematic that it had to switch to something more innovative and farsighted like recharging its supply. The city first delivered corrosive CAP water that rotted out many homeowners’ pipes. That fiasco led to a citizen-backed initiative requiring the city to recharge CAP water rather than run it through a treatment plant.
But in general, many major questions about water-bank recovery remain unanswered. They include: How, when and where will the water be recovered? Who will recover it? How will this be done legally, meeting contractual obligations? How much will it cost?
The water-bank water is stored mainly for the benefit of Tucson and Phoenix and their suburbs, and tribes such as the Gila River Indian Community and the White Mountain Apache Tribe. (The Tohono O’odham Tribe near Tucson is not in line for water-bank water.) Water users along the Colorado River also have a claim to some of the bank’s water.
There is a recovery plan, done in 2014, but to many city water agencies, it’s longer on concepts than details: “It’s a plan to plan,” says Kathryn Sorensen, the city of Phoenix’s water service director. She is secretary for the Arizona Water Banking Authority’s governing commission, and one of many municipal water officials who has pushed hard for a more thorough plan…
The 2014 plan reflects the longstanding, conventional wisdom that CAP cutbacks to cities and tribes wouldn’t start until the mid-2030s at the earliest.
Today, the outlook for Lake Mead and the river in general is worse. Shortages cutting off agricultural water are expected in the early 2020s. Urban shortages are considered possible by the mid-2020s and maybe even 2022, under the worst-case, least-likely scenario.
So water officials are now grappling with the nitty-gritty details of putting together a more complete recovery plan, perhaps by the end of 2018.
The effort is being led by a committee representing various water utilities and other interests, and shepherded by the Central Arizona Water Conservation District, which runs CAP, the Arizona Department of Water Resources and the Arizona Water Banking Authority, which manages the water bank.
Wally Wilson, water service manager for the suburban Metro Water district, said that the big questions about recovery weren’t addressed before, “to the chagrin of many.”
“One thing we know when it comes to water, Arizonans are very innovative,” Sorensen said. “There are a lot of difficulties and a lot of uncertainties. But I know we’ll get there.”