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Challenging Unsustainable Water Use in the San Pedro River

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

What's at Stake

Earthjustice is challenging the Army and U.S. Fish and Wildlife Service to provide protection to the San Pedro River in Arizona, a miraculous desert river that provides habitat for an extraordinary array of birds and other wildlife.

Case Overview

Earthjustice represented the Center for Biological Diversity and the Maricopa Audubon Society in challenging the lawfulness of a U.S. Fish and Wildlife Service biological opinion, which concluded that continued groundwater pumping by the Army for Fort Huachuca, a U.S. Army base near Sierra Vista, Arizona, will not unduly impact the San Pedro River. The lawsuit argued that the existing biological opinion unlawfully failed to protect two endangered species that depend on the river—the Huachuca water umbel (a plant) and the Southwestern willow flycatcher—as required by the Endangered Species Act. In May 2011, Earthjustice won this case in the District of Arizona. We sued again in 2014 to force the Army/FWS to produce a new biological opinion, which was released on March 31, 2014 Our next step is to make sure this new one complies with the Endangered Species Act.

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. This was the third lawsuit the groups filed challenging the Fort's water use.

Case ID

2413, 2459

Case Updates

June 10, 2014 | Press Release: Victory

Court Upholds the San Pedro River’s Right to Water

Arizona Superior Court Judge Crane McClennen today reversed and vacated the Arizona Department of Water Resources’ (ADWR) approval of a massive groundwater pumping project that would have drained the Upper San Pedro River in Southern Arizona.  The court concluded tha

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