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For Immediate Release, January 26, 2011

Contact: Dr. Robin Silver, (602) 799-3275

Study: Peril From Fort Huachuca/Sierra Vista Groundwater Pumping Nears San Pedro River

TUCSON, Ariz.— A new hydrology study from the Center for Biological Diversity shows that the effects of Fort Huachuca and city of Sierra Vista groundwater pumping are moving perilously closer to the San Pedro River, which is the Southwest’s last surviving undammed desert river. Well-water levels are declining near the river at the Fort’s eastern border.

The Center’s new study follows up on a 2005 U.S. Army Corps of Engineers report titled “Compilation and Analysis of April 1995 to April 2005 Water-Level Data at Monitoring and Test Wells, Fort Huachuca AZ.” The 2005 report concluded that:

From analysis of water-level data from 1995-2005, a clear trend has developed. The cone of depression in the Fort Huachuca area is growing, and measured water levels within 2 miles of the river have been declining…it is likely this decline in water levels currently extends to the river, resulting in a reduction of groundwater discharge to the river when compared to predevelopment conditions.

A cone of depression is a cone-shaped hole that develops in an aquifer’s water table in the immediate vicinity of a well or a group of closely associated wells as the result of groundwater removal.

The Center’s new study shows that the trend identified by the Corps in 2005 continues.

Groundwater-dependent activities related to and subsidized by Fort Huachuca jeopardize the San Pedro River and its endangered species. Pumping continues to increase to support expanding local, groundwater-dependent Department of Defense activities.

A 2003 congressional legislative rider sponsored by former Rep. Rick Renzi (R-Ariz.) shields Fort Huachuca from full responsibility for its negative impacts on the San Pedro River and its endangered species. Sen. John McCain (R-Ariz.) supported Renzi’s legislation based on the Upper San Pedro Partnership’s Sept. 9, 2003 promise “to eliminate deficit groundwater pumping by 2011.”

However, the Partnership has not kept its promise; the annual local groundwater deficit or overdraft is now approximately 6,000 acre-feet/year and growing. The Center’s new study establishes that jeopardy to the San Pedro and its wildlife has increased as the effects of Fort Huachuca/Sierra Vista groundwater pumping move closer to the river.

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