SIERRA VISTA, Ariz.— As a direct result of a lawsuit by the Center for Biological Diversity and the San Pedro 100, Arizona Gov. Katie Hobbs will conduct a review to determine if the designation guaranteeing a 100-year water supply for developer Castle & Cooke’s 7,000-home Sierra Vista development should be revoked because of a lack of water.

The homes would rely on groundwater that is no longer available after a recent Water Adjudication Court ruling. The groundwater feeds the nearby San Pedro River, the Southwest’s last free-flowing river — a vital lifeline for plants and animals across southeastern Arizona.

“This lawsuit forced the governor to finally face the simple reality that there’s just not enough water for existing homes in Sierra Vista, let alone more development,” said Robin Silver, co-founder of the Center. “We’ve known for decades that home construction in the area was based on the fantasy of a limitless water supply. The inevitable revocation of Pueblo del Sol’s water-supply designation will come far too late but will give the San Pedro River a fighting chance at survival.”

In 2013 the Arizona Department of Water Resources granted Castle & Cooke’s Pueblo Del Sol water company a 100-year designation of adequate water supply for its development without any consideration of then unquantified but congressionally assigned federal reserved water rights for the San Pedro Riparian National Conservation Area.

On Aug. 9, 2018, the Arizona Supreme Court ruled this action was legal, saying: “ADWR is not required to consider unquantified federal reserved water rights under its physical availability or legal availability analysis.”

The court’s ruling acknowledged that when federal reserved water rights were quantified, water department officials must respect them. Dissenting justices noted that “[t]his interpretation defeats the adequate water supply provision’s manifest purpose to proactively protect consumers in Arizona before they purchase property.”

That decades-long legal battle ended on Aug. 25, 2023, when Maricopa County Superior Court Judge Mark H. Brain issued a ruling quantifying water rights for the San Pedro Riparian National Conservation Area.

The ruling mandated that groundwater levels be maintained at nine monitoring wells within the conservation area. Four of those wells have already dropped below their required elevation, in violation of the ruling. Water levels in a fifth well are on a downward trend and edging closer to a violation.

A 2014 U.S. Geological Service study showed that by 2114 between 10% and 60% of the water withdrawn by Pueblo del Sol’s wells will be water denied to the San Pedro National Riparian Conservation Area.

Current declining water levels show that the area’s historic cumulative groundwater pumping of approximately 2 million acre-feet since 1940 is overtaking efforts to mitigate the local groundwater extraction.

The Center has filed complaints calling on the governor to review and revoke 100-year designations of adequate water for 35 additional subdivisions in the Sierra Vista area. Those complaints have gone unanswered and await pending litigation

Gov. Hobbs visited the San Pedro this week to tout a grant for an ineffective and inconsequential stormwater recharge project, instead of taking on the region’s developers and limiting growth, the only substantive action that will save the San Pedro River.

“Gov. Hobbs’s PR stunt at the San Pedro this week was a poor attempt to show she actually cares about the river or is concerned about Arizona’s environmental legacy,” said Silver. “It shouldn’t take a lawsuit for her to review the water supply for these Sierra Vista mega-developments that are drying up our state’s riparian crown jewel. We’ll keep fighting for the river until the Hobbs administration finally comes to term with the fact that the days of development on the Upper San Pedro have come to an end.”