San Pedro River Condemned by Arizona Department of Water Resources

Massive new development threatens river and wildlife


McCrystie Adams, Earthjustice, (303) 996-9616


Robin Silver, M.D., Center for Biological Diversity, (602) 799-3275

The Arizona Department of Water Resources has approved a massive groundwater pumping project that will drain the Upper San Pedro River in Southern Arizona. This decision comes despite opposition from the property owners along the river and the U.S. Bureau of Land Management (BLM), and ignores the project’s impact on the birds, wildlife, and local residents and businesses that are dependent on a healthy river.

The San Pedro Riparian National Conservation Area. The desert riparian ecosystem of the Upper San Pedro River is one of a few remnants of the formerly extensive network of similar areas throughout the region.  (BLM)

The planned groundwater pumping will feed massive new development in Sierra Vista, a small city in the desert east of Tucson. By the developers’ own admission, the proposed construction will consume “virtually all of the available development land” left in Sierra Vista, and will significantly expand the population of this critically water-short area.

The developers could not proceed with the project without the State’s determination of an adequate water supply—a determination the State could only make by assuming that there is no connection between groundwater and water in the river.

Incredibly, despite volumes of scientific study demonstrating that the river and the groundwater aquifer are interconnected, the State has now made that determination and the pumping may begin.

“The Upper San Pedro River is the lifeblood of this region,” said Earthjustice attorney McCrystie Adams. “The state of Arizona continues to hold fast to the fiction that groundwater and surface water are not connected. In the meantime, the river is disappearing and the birds, wildlife, and people who depend on a living San Pedro are left high and dry.”

The Upper San Pedro is the last undammed and free-flowing river in the desert Southwest. This desert riparian ecosystem is one of a few remnants of the formerly extensive network of similar areas throughout the region.

The river is a biological treasure, providing important habitat for a wide array of species and a refuge from the impacts of development and climate change. The San Pedro corridor is also one of the most important migratory flyways in the United States; millions of songbirds use the San Pedro each year during their migrations between Central America and Canada.

Importantly, the river is home to the San Pedro Riparian National Conservation Area, a reserve managed by the BLM to protect and enhance this national gem. The area attracts thousands of visitors, who contribute millions of dollars to the local economy, each year.

BLM and property owners—including Dr. Robin Silver—along the river have opposed the determination and may challenge ADWR’s action in court.

Earthjustice has worked with partners for over a decade to sustain the San Pedro River and the rich ecosystems that flourish there. “Allowing this groundwater mining to proceed is signing the death warrant for the river,” added Adams. “This one decision could undo many years of hard work by residents and organizations fighting to keep the San Pedro flowing.”

Earthjustice is reviewing legal options with Dr. Silver.

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