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San Pedro River Water Use Challenge

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 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’s biological opinion, which concluded that continued, even increased, water withdrawals by the Army for Fort Huachuca, a U.S. Army base near Sierra Vista, Arizona, will not unduly impact the San Pedro River. In May 2011, Earthjustice won this case in the District of Arizona.

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 lawsuit argued that two species—the Huachuca water umbel (a plant) and the Southwestern willow flycatcher—will be threatened with extinction if the opinion was allowed to stand.

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. The annual local groundwater deficit, or overdraft, of the aquifer is now approximately 6,000 acre-feet per year and growing. This was the third lawsuit the groups filed challenging the Fort's water use.

Case ID

2413, 2459

Related Features

Case Updates

June 10, 2014 | Press Release

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