Tucson has 5.5 years of excess Colorado River water stowed in a "secret" reservoir

JUANA SUMMERS, HOST:

It is drier than it has been in the Southwest for 1,200 years. And the fast-growing states there that rely on the Colorado River are seeing their water deliveries being cut out like never before. But as NPR's Kirk Siegler reports, in Arizona anyway, few people appear to be panicking.

KIRK SIEGLER, BYLINE: Tucson's water manager, John Kmiec, is standing on a patch of desert shrub more than 330 miles from the shrinking Colorado River. Tucson gets the bulk of all of its drinking water from the river, but there's no five-alarm fire right here.

JOHN KMIEC: And now we have a shortage condition on the Colorado River, but it's really not going to affect the Tucson Basin.

SIEGLER: It's not? Kmiec says there are two big reasons why. The first is aggressive conservation, like water recycling. Tucson uses the same amount of water as it did in the 1980s, yet it's added 200,000 more people.

KMIEC: It's all about adaptation and making sure you - the water that you use, particularly in the desert, is for what you need.

SIEGLER: But the other, even bigger reason why Kmiec isn't up all night worrying?

KMIEC: Because we've banked more than 5 1/2 years of excess Colorado River water in these aquifers already.

SIEGLER: You can think of it like a secret reservoir hidden underneath this vast Sonoran Desert, with its blazing sun and saguaro cactus.

KMIEC: It looks like about a 40-acre basin, the one we're standing next to.

SIEGLER: This basin is mostly dry dirt with occasional stalks of green grass from recent monsoons, not exactly what you picture when you think of a city's water plant, though another basin in front of us does have some water.

KMIEC: We fill these large reservoirs up. They look like small lakes. But what's actually happening is the water is slowly going down and percolating into the aquifer and back and turning into groundwater.

SIEGLER: For more than 20 years now, Tucson has been preparing for this crisis, pumping its legal share of Colorado River water from the federally built canal into the ground right here.

(SOUNDBITE OF RUSHING WATER)

SIEGLER: The idea is you bank the water for lean times. The excess is then pumped back out of the ground and into taps in the city about 30 miles east of here. In fact, a lot of Arizona has been banking its Colorado River water in underground reservoirs like this for decades. The state pioneered the practice because it had to, says Kathryn Sorensen. She's a water policy expert at Arizona State University.

KATHRYN SORENSEN: It's a secret underground reservoir. You're right. Most people really aren't that interested in water issues until there's a crisis.

SIEGLER: Sorensen says Arizona has long known its water rights are junior to California's, so they have to bank the river water they are given and aggressively conserve the rest.

SORENSEN: I think the advantage of - that water planners in Arizona have is that it is a desert. And we do have lower priority water to the Colorado River, so you know to plan for worst case.

SIEGLER: This may be why in a lot of Arizona right now, it doesn't really feel like anything is out of the ordinary. You don't see signs urging conservation in hotels or restaurants. Sidewalk misters are running full bore in 108 degree heat. Some farms have been cut off, but there's no rationing in cities. Still, a 5 1/2-year supply in Tucson's water bank doesn't sound like much to city councilman Steve Kozachik.

STEVE KOZACHIK: For us to be assuming or hoping that the drought is going to end is a false hope. This is the climate reality that we're living in.

SIEGLER: Kozachik cast a lone vote recently against the city taking all of its entitled Colorado River water. He says Tucson should lead by example.

KOZACHIK: Three years from now, five years from now, whenever it is, we can all be standing along the banks of the Colorado looking at a drive riverbed, saying all I did was take what I was entitled to. And we sucked it dry.

SIEGLER: Kozachik says every user in this basin needs to come to the table now and agree to use significantly less water. Otherwise, the Colorado really will run dry.

Kirk Siegler, NPR News, Tucson. Transcript provided by NPR, Copyright NPR.