Conservation groups have filed a lawsuit against Arizona Governor Katie Hobbs and Arizona Department of Water Resources Director Tom Buschatzke for their alleged failure to safeguard the San Pedro River. The San Pedro Alliance, which comprises local, regional, and national organizations, submitted a petition in September 2023 urging the establishment of an active management area (AMA) in the Upper San Pedro Basin. However, both officials have reportedly failed to respond.
The San Pedro River, recognized as the last free-flowing desert river in the Southwest, supports several endangered species, including the Southwestern willow flycatcher and the Huachuca water umbel.
Groundwater pumping from the over-drafted local aquifer is critically threatening this vital ecosystem. According to Robin Silver, co-founder of the Center for Biological Diversity, the Governor’s inaction undermines the Arizona Groundwater Management Act, leading to potentially catastrophic outcomes for the river and its dependent species.
Arizona’s Groundwater Management Act of 1980 mandates the designation of active management areas to preserve groundwater for future needs. It also requires the Department of Water Resources to certify the availability of a 100-year water supply for developments within these areas. Attorney General Kris Mayes highlighted that the Department has inadequately reviewed the Upper San Pedro Basin, conducting only two studies in 40 years. The recent lawsuit seeks judicial intervention to address these regulatory lapses.
The San Pedro Alliance’s earlier 2005 petition for an AMA was denied by the state water department, which disregarded the San Pedro River and its federally reserved water rights. The EPA also objected to a large-scale development in Benson, citing potential significant impacts on the San Pedro River. Subsequent reports from multiple studies have also documented or predicted the river’s deterioration.
In 2023, federal water rights for the San Pedro Riparian National Conservation Area were quantified, mandating minimum water levels at specific monitoring wells. However, violations have already been observed at the Cottonwood and Summers wells. This quantification necessitates the revision of at least 67 basin adequacy certificates, including those for the 28,000-home Vigneto development in Benson, to prevent further depletion of the San Pedro River’s water supply.
Tricia Gerrodette, president of San Pedro 100, emphasized the urgency of establishing an AMA in the Upper San Pedro Basin. Despite numerous studies indicating severe over-drafting, the state has continued to permit new wells under Buschatzke’s leadership. Gerrodette stressed that the lack of action threatens the river’s future viability, underscoring the necessity for immediate regulatory intervention.
