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Study: Stark picture for Arizona water supply, Tucson could be oasis in desert

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Colorado River

TUCSON (KVOA)-- Arizona has been in a state of drought for two decades. For the first time in the modern history of the Colorado River, a water shortage will likely be declared at Lake Mead. Couple this with increasing temperatures and climate change and it could spell trouble for Arizona's water supply.

A report released in May by the Kyl Center for Water Policy paints a stark picture for the water supply in Arizona. "First of all we've got too many people using groundwater. we've got to find ways to curb that use," said Kathleen Ferris, a senior research fellow at the Kyl Center.

The report says most of the state is not achieving safe-yield, not pumping more groundwater than can be replenished. "In other words, as long as we continue , we call it mine groundwater, which means take more out than you are replenishing, the less groundwater you have. And groundwater is a finite supply," Ferris said.

But could Tucson be the oasis in the desert?

Unlike Phoenix, Tucson is at or near safe-yield. "Tucson is in a little better shape than the other active management areas at the moment, but the Department of Water Resources is saying the ability to maintain that goal is in jeopardy," Ferris said.

The city started taking deliveries of Colorado River water 20 years ago. "On a net balance level 100% of Tucson Water's use is Colorado River water," said Tucson Water's Superintendent of Public Information and Conservation, James MacAdam. That means the utility is still pumping groundwater in some parts of town. But it's taking in an equivalent amount of Colorado River water and recharging it.

Tucson Water has actually been banking water. "Tucson water has been playing the long game for decades. Our allocation from the Colorado River is 144,000 acre feet a year, our water use is about 90-100 acres a year. So that means over the past several years we've actually been banking a half year's worth of water in the aquifer every year," said MacAdam.

The city is in that position because Tucsonans have been really great at conserving water. "Per capita water usage in Tucson has been dropping since the 1970's. About 1-2% per year, it actually accelerated 10-15 years ago." said Pofesser Thomas Meixner, Department head of Hydrology and Atmospheric Sciences at the University of Arizona. Tucson Water also said its users have reduced their water use 30% per person over the past decades.

Tucsonans have also embraced the desert landscape. Grass lawns are rare. Net-zero yards are now more the norm than the exception. But one of the biggest challenges the state faces is the influx of new residents and the ensuing construction. Ferris doesn't think Tucson will be able to sustain safe-yield over the long term." We have too much development on raw desert land and all that does is bring new uses into the system. It doesn't do anything to curb existing uses," Ferris said.

But McAdam says the utility is capable of handling the growing population. "People moving here from other places, growing our population, growing our economy, we have managed that over the past 30 years by decoupling water use and growth. What that means is that we have added 220,000 customers while using the same amount of water," he said.

The Kyl Center report says conservation isn't enough at this point. The state needs new, bold water policies. Arizona lawmakers passed the Groundwater Management Act in 1980, with the goal of achieving safe-yield by 2025. A goal it now says will be impossible under current regulations of the Arizona Department of Water Resources. One recommendation is to address long-term rights to pump groundwater, including a fee or tax on mined groundwater.

Tucson Water is also looking to alternative water sources, like rain or storm water. The utility offers customers up to a $2000 rebate for installation of rainwater harvesting systems. It also has a green storm water infrastructure mini-grants program that provides funding for neighborhoods who install water harvesting systems which capture water off of the street.

And while Tucson is in good shape, experts say it's not time to get complacent. "We will have choices as a state that we will need to make," Ferris said.

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