Sonoran Desert dwellers between Tucson and Phoenix might one day be able to boat the Colorado River without leaving their backyards. Rural Pinal County says it wants to take a billion gallons of Colorado River water and pump it into a manmade lake.


Thanks to the Central Arizona Project, the three-quarter mile, $7 million reservoir in the Picacho Lake Recreation Area could fill by December 2001. Sun and aridity will dry up the shallow lake unless it's replenished each year, but Cheryl Banta of the county's Public Works Department says that level of evaporation is "normal, for the desert."


Normal, too, is the state's growing demand for water. But while CAP gets 1.5 million acre-feet of the Colorado River annually, the project's users, including municipalities, industry, farmers and Indian tribes, don't use it all - yet. Bob Barrett, spokesman for CAP, says some users have permanent CAP allotments but have never taken a drop. That means some of that 1.5 million acre-feet is currently available through an "excess water contract" for a new desert lake. Barrett warns, however, that the situation will change.


"I can stand here and tell you that for the next 30 years there's going to be excess water," Barrett says. "I'm pretty sure of that. But at some point, all of our customers will take their allotment. At that point, Picacho gets no water."


Not unless a permanent water right becomes available, he adds. If an existing user decides to sell, Picacho could then try to buy or lease rights for a time. The odds of that are "pretty fair," Barrett says. "It's a question of price." Indian tribes may sell or lease their water rights free of price controls, at least for now.


Picacho will cross that bridge when it comes to it. Arizonans clamor for water-based recreation, Banta says, and for many Tucson residents, this would be their closest lake. Patagonia Lake, south of Tucson, hosts 295,000 people a year, and Picacho would attract even more, she says.


Besides, she adds, right now those billion gallons just float down the Colorado River. "We're not asking for an allocation that's currently going to farmers or cities or anyone. That's why we think this is a great idea, because it's not being used."


Critics say that unused CAP water could better be put to work recharging depleted aquifers; even with CAP, Tucson's is dropping six feet a year. And Kieran Suckling, co-founder of the Center for Biological Diversity, says creating a fake lake in the desert resembles "clear-cutting a forest in Minnesota and planting cactuses."


Suckling has another idea for those billion gallons: Save the river's dying delta. "You could leave the water in the Colorado River," he says. "God forbid anyone think of that!'


* Karen Mockler