The San Pedro River north of Hunter Wash. 2008 photo. Courtesy Bureau of Land Management.

Courtesy Bureau of Land Management.

In the name of keeping the San Pedro River alive, the federal government is trying to stop Arizona from certifying that a planned Sierra Vista development has enough water for 100 years.

The U.S. Bureau of Land Management's effort is the first time in years that the feds have questioned development in that area due to concerns about groundwater pumping possibly drying up the San Pedro, the Southwest's last free-flowing desert river.

"We're about to see some heavy battles. There are real issues here" that could set a precedent for the Sierra Vista area, said Thomas Maddock, a University of Arizona hydrology professor who has studied the San Pedro for years.

At issue is a project called Tribute, of 5,800 single-family homes, 1,100 apartments and commercial development. Approved by Sierra Vista in 2006, it is scheduled to start construction this year.

The consultant for the developer, California-based Castle & Cooke Associates, says its computer model found that pumping for Tribute would not lower the water table more than 1,200 feet over 100 years. That typically meets the legal definition of an adequate water supply.

But in a March 16 letter to the state, the BLM said the development's supply isn't legally available. That's because the San Pedro's flow is protected by federal water rights superior to the developer's right to pump groundwater, wrote Julie Decker, a deputy BLM director for Arizona.

The 40-mile-long San Pedro Riparian National Conservation Area was created by Congress in 1988 with an express water right, Decker wrote.

Rick Coffman, a Castle & Cooke vice president, said that the feds' San Pedro right covers only surface water, not groundwater.

"I am not sure why they are even commenting. I presume ADWR (the Arizona Department of Water Resources) will respond the same," Coffman said in an email Friday.

After taking public comments, the state water agency will decide who's right.

Chuck Potucek, Sierra Vista's city manager, said it's hard for him to say how he'll react if the BLM prevails. "I don't see a basis for not allowing (Tribute). ... If they're looking strictly at supply, my statement stands. If they do take these other things into account, who knows?"

The case comes at a time the state has more clout than it used to on water decisions in Sierra Vista. Until 2008, a state ruling of inadequate water was only a red flag to homebuyers and lenders. That's because Sierra Vista, unlike Tucson, is not in an active management area, where a developer must prove a 100-year supply to build.

But under a 2008 change in state law, a development such as Tribute, which had gotten its rezoning but not yet its subdivision plat before that law changed, can't build without a state designation of adequate supply, Arizona water officials said.

State water officials have not made many waves regarding the San Pedro since 1993, when they said that generally, water supplies are legally available for new subdivisions there, reversing a previous policy that said the opposite.

Since then, the state water agency has found that all but eight of more than 90 new developments in that area had adequate water.

"This is a very positive sign," said UA law professor Robert Glennon, referring to the BLM's new stance. "There's a federal preserve that they are bound as fiduciaries to protect."

Glennon noted that a 1976 U.S. Supreme Court case gave the Devil's Hole National Monument in Nevada senior water rights over a rancher two miles away who wanted to drill a well. That's even though the monument - unlike the San Pedro conservation area -didn't have water rights established in writing, Glennon said.

"It would be outrageous for ADWR, in the face of this very powerful federal legal claim," to decide in the developer's favor, Glennon said.

In her letter, the BLM's Decker noted that overdrafting of groundwater in the Sierra Vista area - about 6,000 acre-feet annually - is continuing despite a legal requirement to have ended it by September 2011.

She also wrote that the state shouldn't grant Tribute adequate-supply designation until state courts rule on who has the highest priority water rights in the entire Gila River Basin, including the San Pedro. That court case has lasted since 1978 with no end in sight.

Decker also pointed out that there are now more than 8,500 unregulated wells in the Upper San Pedro Basin, a 74 percent increase since 1990.

Robin Silver, a Flagstaff environmentalist who has fought to save the San Pedro for years, said, "There is not sufficient water in the Fort Huachuca/Sierra Vista area for any further unmitigated growth without further damage to the San Pedro River. ... Finally, BLM joins us in calling out ADWR."

Sierra Vista's Potucek said, in effect, that if this development is turned down, it wouldn't be a critical loss because of the economic slowdown.

"This development was approved six years ago. Nothing's happened. The town didn't end. The economy has slowed down. It's not like cars have been lined up on Highway 90 for people to move in," he said.

To comment on this case

Any resident or landowner of the Upper San Pedro groundwater basin may by May 10 file a written objection to the possibility of the state issuing a designation of adequate water supply, if they include their name, address and signature. Under the law, only objections are accepted, said Thomas Buschatzke, an assistant director of the Department of Water Resources. Mail comments to Docket Supervisor, Arizona Department of Water Resources, Legal Division, 3550 North Central Ave., Second Floor, Phoenix, AZ 85012.

Contact reporter Tony Davis at or 806-7746.