Tucson-area golf courses enjoy a world-class reputation. They attract duffers from around the globe to lush landscapes that spring from a harsh, dry desert.

But behind their temperate facade lies a blistering reality: Billions of gallons of water are needed annually to keep the links green.

And water experts say the flow affects all Tucsonans because it can diminish the quality - and quantity - of drinking water by draining underground reserves.

"As a matter of environmental ethics, it's crucial that we employ our natural resources in a sustainable fashion," University of Arizona law professor Robert Glennon said in a recent speech about Arizona's Ground Water Management Act.

"Quite simply, we have a moral obligation to consider future generations."

That obligation is not disputed by politicians, water experts or groundskeepers.

The debate instead is focused on how effectively - and economically - to handle the challenge of switching the area's golf courses from ground water to treated wastewater.

That debate will take on a new emphasis across Arizona under a plan by Gov. Jane Hull to re-examine the state's 20-year-old Ground Water Act and find ways to achieve "safe yield" - a balance in which the amount of water pumped from the ground does not exceed its replenishment - by the year 2025.

Achieving that in Tucson will depend partly on golf courses because:
 

• Twenty-four of the area's 38 courses use ground water and last year pumped 3.8 billion gallons onto their greens.
•  An additional 25 courses are expected to be built in the Tucson area during the next few decades.

The new courses won't be as challenging because more of them will be using such renewable supplies as treated wastewater or imported Colorado River, or CAP water, says Kathy Jacobs of the Tucson office of the Arizona Department of Water Resources.

The real issue will be getting the older courses - those that hold ground-water rights - to make the switch.

And the problem with that, according to Brent Newcomb, city administrator of golf operations, is economics.

Tucson Country Club, for example, continues to use ground water even though it's connected to the city's 85-mile reclaimed water pipeline.

That's because it costs $100 to $150 to pump and deliver an acre- foot of ground water and $475 for the same amount of treated water. And connecting to the pipeline isn't cheap.

Rolling Hills Country Club, for example, would have to pay about $4.1 million to design and build a connecting transmission main and another $500,000 to upgrade a pumping station.

One solution that's being considered in Oro Valley and Green Valley is to cover the costs through tax-levying water authorities. Another approach - currently directed at some Tucson courses - is to put limits on the amount of ground water that can be used but no restrictions on consumption of treated water.

Countering conservation is overseeding in winter by some courses that jumped from 21 percent of all area turf in 1985 to 60 percent last year. And that, some experts say, is another reason to encourage the switch.

"We need to continue toward more full utilization of Central Arizona Project water," the state's Jacobs says. "That's probably the highest priority."

What do you think?

• Should all golf courses be required to stop using ground water and instead feed their greens with treated water? 
• If so, how should the conversion be financed? 
• Should public funds be used to pay the costs? Should developers shoulder the expense? Or should a combination of public and private money be used? 
• If golf courses are required to use treated water, should private consumers also be asked to change their water habits? For example, should more CAP water be used in the public supply? 

What other alternatives can be considered to get golf courses - and others - to stop depleting the ground water supply?