Pete Byers, a supervisor in Arizona's Mohave County, says two proposals to build Las Vegas bedroom communities in northwest Arizona are in trouble on the issue of adequate long-term water supply. Photo by Dave Hawkins/Special to the Review-Journal.

KINGMAN, Ariz. -- The Arizona Department of Water Resources has put Las Vegas-based developers on notice that they've not yet sufficiently demonstrated adequate water supply for master-planned communities that they propose to build in northwest Arizona.

Jim Rhodes and Leonard Mardian have earned preliminary county-level approvals to continue planning what they perceive to be future Las Vegas bedroom communities off U.S. Highway 93 south of Hoover Dam. They still, however, require a number of other approvals from local and state entities to pursue development of the Village at White Hills (Rhodes) and the Ranch at White Hills (Mardian).

The water agency has sent letters to Rhodes and Mardian indicating concern about their applications for determination of water supply adequacy. Director Herb Guenther said his agency can approve the applications only if developers can demonstrate that sufficient water is "physically, legally and continuously available" for 100 years.

"These two proposed communities total in excess of 62,000 lots and would require approximately 25,000 acre-feet of groundwater," Guenther said in letters sent to Mardian and Rhodes. An acre-foot of water is almost enough to supply the needs of two Las Vegas Valley households for one year.

"We felt it was important to bring to your attention that at this time, based on information that is available, that the department feels that it is unlikely that adequate supplies of groundwater are physically available for the proposed uses in the pending applications," he wrote.

Mohave County Supervisor Pete Byers said the letters are important. He said the proposed communities could be in jeopardy of rejection or significant modification.

"They're going to have to scale these projects back tremendously or they're not going to be able to build as far as I'm concerned," Byers said.

"But they may have a legal way. These people are very powerful and have lots of money, so they may be able to circumvent something, but as far as I'm concerned I don't want to have these aquifers damaged," he said.

Guenther said that the Department of Water Resources is receptive to additional input and information regarding water supply before making any final determination regarding the water adequacy applications for the proposed developments.

A Mardian spokesman said the developer has provided additional information that could resolve the problem.

"We believe that the letter from the ADWR was written before the department had reviewed new information that we provided at the request of their scientist," Mardian spokesman Brian Tassinari said. "Based on the testing from the additional wells that we've drilled, our water experts believe we can prove there's enough water to support our planned community."

Rhodes spokesman Bill Marion declined comment, saying he would respond when he could.

Guenther said the developers could abandon or scale back their projects if they can't prove they have a 100-year supply.

"They have sizable investments involved here, and we did not want them assuming that approval of their water adequacy applications is forthcoming," he said.

Guenther also noted that Rhodes and Mardian conceivably could push the projects through without application approval, but that they would be required to disclose the lack thereof to prospective lot purchasers.

Water officials said that even though the proposed developments are near the Colorado River, which provides water for Las Vegas and the Phoenix area, all of Arizona's water from the river is already allocated.