Challenging Unsustainable Water Use in the San Pedro River

Arizona's "River of Life," the San Pedro River is a surviving remnant of a once extensive network of desert riparian corridors that traversed the Southwest. The last major free-flowing river in the desert Southwest, the San Pedro is a sanctuary for millions of migratory birds and home to multiple endangered species including the jaguar and southwestern willow flycatcher.

Case Overview

Recognized as a world heritage natural area by the United Nations World Heritage program, the San Pedro River supports 400 species of birds (nearly half of the U.S. total), 100 species of butterflies, 83 species of mammals and 47 species of amphibians and reptiles.

The San Pedro is the Southwest’s last surviving undammed desert river, threatened by local groundwater pumping that intercepts water that would ordinarily move from the aquifer seeping through the riverbanks to provide surface flow to the river.

Reduction of the river’s flows have already adversely affected the riparian and wetland vegetation surrounding the river, as well as species dependent on riparian habitat.

For years, Earthjustice and our clients have engaged in a series of legal actions to defend the San Pedro River and its riparian vegetation and springs from irresponsible, unsustainable groundwater pumping.

The San Pedro River.
The San Pedro River is a remnant of a once extensive network of desert riparian corridors that traversed the Southwest. (Melanie Kay / Earthjustice)

Case Updates

April 18, 2022 Press Release

San Pedro River Named Among America’s Most Endangered Rivers of 2022

Groundwater pumping, harmful development threaten endangered fish and wildlife 

December 22, 2020 document

Memorandum in Support of Motion for Partial Summary Judgment on NEPA & CWA

Memorandum in Support of Motion for Partial Summary Judgment on NEPA & CWA

December 22, 2020 document

Motion for Partial Summary Judgment on NEPA & CWA

Motion for Partial Summary Judgment on NEPA & CWA