The groups on Wednesday demanded a legislative audit be conducted on the division to force open the agency's process for justifying expensive water-development projects, such as the Lake Powell Pipeline and the Bear River Development.
While they don't relish the idea of an audit, division leaders say they have nothing to hide.
"We try to use the best numbers. They are hard to pin down, and our methodology has changed over the years," said Eric Millis, deputy director of the Division of Water Resources. "We're not interested in inflating numbers. We aren't going to do this [construct water projects] before it's needed."
The Utah division tries to include all municipal and industrial use, including the unmetered water some residences put on gardens, according to Millis.
"We don't compare well with other cities because we report things differently," he said. Phoenix, for example, does not include secondary water or apartment complexes in its per-capita use calculations.
In 2000, the baseline year Utah uses for its 25 percent conservation goal, per-capita water use here was 295 gallons per day, the agency estimates. That's down from 320 gallons in 1995, said Eric Klotz, the division's water conservation director.
Frankel and his allies remain skeptical because Utah's water district officials frequently release conflicting water-use numbers. Critics believe if Utahns' municipal use is actually lower than officials say and conservation goals adjusted, the state could put off developing new water supplies for decades.
"There's a lot of doubt that needs to be resolved," said Steve Erickson, a legislative advocate for the Great Salt Lake Audubon. "We are not dismissing that we may need to augment our water supply, but we have time to do a rational examination of what's the best mix of policy options to achieve water security."
To bolster their claims, the environmentalists cite "Strong's Law," a dictum referencing Utah water resources director Dennis Strong's famous pronouncement that whenever water is conserved something dies.
This shows the division's bias against conservation at the expense of taxpayers and the environment, Frankel contends.
Among the nation's most profligate water wasters, Utah should create stronger incentives to use less, he says. Good places to start are stepping up tiered rate structures, so that residences that use more water pay more per gallon, and ending the use of property taxes to subsidize water development.