Southern Arizona Developments Sued Over Federal Groundwater Rights

Fifty-five southern Arizona subdivisions stand accused of illegally diverting water from federally protected wetlands, according to a recent lawsuit filed by conservationists. The Center for Biological Diversity and San Pedro 100 allege that since at least 2006, these developments have been undermining the ecological integrity of the San Pedro River.

The lawsuit challenges 100-year water supply designations for various Sierra Vista subdivisions, referencing a 2023 court ruling that established water rights for the San Pedro National Riparian Conservation Area. The plaintiffs are pressing the Arizona Department of Water Resources to reassess the viability of these developments, particularly in light of concerns over the potential draining of the last free-flowing river in the Southwest.

“Governor Hobbs and Director Buschatzke refuse to acknowledge the over-pumping in Sierra Vista, which violates the San Pedro River’s water rights,” stated Robin Silver, co-founder of the Center for Biological Diversity. “Despite laws requiring a review of inaccurate water adequacy designations and mandates for consumer protections, we find ourselves taking legal action against Arizona.”

The lawsuit emphasizes the San Pedro River’s critical role as a habitat for migratory birds and endangered species. Conservationists contend that groundwater extraction, primarily for residential developments and a U.S. Army base, has led to significant drops in water levels across court-monitored wells, with six of thirteen wells falling below legally mandated thresholds.

Furthermore, the plaintiffs accuse the Arizona Department of Water Resources of violating the Arizona Consumer Fraud Act by assuring developers of water access that may not legally exist. They argue that both Governor Katie Hobbs and Department Director Tom Buschatzke have disregarded these serious allegations for two years.

Following a prior lawsuit from the Center in August 2024, the department agreed to reevaluate the water-supply designation for Pueblo Del Sol, a development comprising 7,000 homes. This indicates a tense environment surrounding water rights and development in the area.

Earlier in June 2024, the Center had sought a ruling for the riparian area to be declared an active management area, ensuring closer monitoring of groundwater usage. However, a state judge dismissed this challenge in January.

Central to the current lawsuit are water rights established in 1988, when Congress reserved water for conservation purposes. Despite this, the rights were never quantified, allowing the state to allocate them to developers. A 2018 Arizona Supreme Court ruling upheld this allocation, leaving it to the department’s judgment regarding water rights reservations.

Dissenting justices in that case noted concerns that such interpretations undermine protections for consumers purchasing property in Arizona.

A recent turn of events occurred in August 2023 when Maricopa County Judge Mark H. Brain issued a ruling that quantified water rights for the conservation area. This ruling could potentially invalidate the water rights granted to the 55 subdivisions implicated in the lawsuit.

As of now, the Arizona Department of Water Resources has yet to respond to requests for comment on the ongoing legal situation.