Groups seek review of Ft. Huachuca pumping
Conservation activists are pressing for the federal government to reexamine the effects of groundwater pumping at Fort Huachuca in southern Arizona, pointing to a confidential 2010 study commissioned by the Army base that detailed how the area’s wells are taking a growing toll on the flow of the San Pedro River.
The leaked 2010 report was released by Robin Silver, a co-founder of the Center for Biological Diversity, who said the findings show the base’s groundwater pumping has been harming the river for years and will do more damage unless water use is scaled back.
Silver said the study’s projections of worsening effects on the river’s flow in the coming decades weren’t adequately considered when U.S. Fish and Wildlife Service officials issued an opinion in 2014 approving the base’s groundwater pumping for another decade.
“The damage was already attribut
able to Fort Huachuca when they started their evaluation, and that has to be accounted for,” Silver said.
The San Pedro River, which runs near Fort Huachuca and Sierra Vista, is sustained by water that flows from an underground aquifer. The river forms a vibrant oasis for birds and wildlife, and conservationists have been warning for years that greater efforts are needed to prevent the San Pedro from drying up.
Study notes link between wells and rivers
The 2010 study examined pumping from wells on the base and also pumping from other wells in the area that are related to the fort. The report maps declines in streamflow due to what it calls “fort-attributable” pumping in 2003, as well as projections for 2050 and 2105 based on federal data.
The study was prepared for Fort Huachuca by the contractor GeoSystems Analysis, Inc.
The document is marked “CONFIDENTIAL; FOR OFFICIAL USE ONLY.”
The report says projected pumping on and off the base would account for 19% of all pumping and 65% of “total baseflow capture” in the Upper San Pedro Basin by 2105. It says projections show stream depletion linked to fort-related pumping would be concentrated at the confluence of the San Pedro River and the Babocomari River, and several miles upstream on each river.
Depletion of streamflow due to the base’s pumping is projected to peak in the mid-21st Century, the report says, and include two 250-meter (820-foot) stream reaches that would be “pumped dry” on the Babocomari in 2050. The study projects that all fort-related pumping could dry up as many as five stretches of the rivers by the middle of the century.
The study also said there is a strong connection between pumping from wells on the base and effects on the two rivers.
“For this reason, reducing or eliminating production from these wells may prove to be one of the most effective means for mitigating the Fort’s pumping-induced depletions of stream baseflow,” the report says.
The Center for Biological Diversity and two other conservation groups — Maricopa Audubon Society and the Sierra Club — argue the report’s findings should have been considered in the Fish and Wildlife Service’s most recent biological opinion examining Fort Huachuca’s effects on the San Pedro River.
The three groups filed a notice Dec. 3 informing the government they intend to sue Fort Huachuca and the Fish and Wildlife Service in 60 days if the agencies don’t address violations of the Endangered Species Act and carry out a new review.
The groups said in their notice that Fort Huachuca “covered up” the 2010 report and failed to provide it to the Fish and Wildlife Service as officials were preparing their opinion, which authorized the base’s groundwater pumping for another decade. The environmental groups said if the base hadn’t “covered up” the conclusions of the report, Fort Huachuca’s pumping “would not have been cleared to the current levels.”
Silver said in a statement that the report makes clear “Fort Huachuca should’ve been downsized in 2014 rather than given the green light to keep damaging the San Pedro.”
Base says study guided earlier decisions
Fort Huachuca responded to questions from The Arizona Republic in a written statement. It said the Fish and Wildlife Service and the Army “completed a very thorough formal consultation in 2014, regarding the potential effects of Fort Huachuca’s operations.”
The Army base’s statement noted that the 2010 report — while not publicly released until this month — was cited in the 2014 biological opinion and “used as part of the overall determination issued by U.S. Fish and Wildlife Service.” It repeated the wildlife agency’s conclusion that the Army base’s current and planned operations “are not likely to jeopardize the continued survival or recovery” of any threatened or endangered species.
The base says it has a total population of about 14,500, including full-time military personnel, military students, civilian employees and contractors.
Angela Camara, a spokesperson for Fort Huachuca, said she couldn’t comment on the pending litigation.
In their notice to the government, the conservation groups said the San Pedro’s base flow is disappearing because of “the Fort Huachuca/Sierra Vista area’s excessive, uncontrolled, deficit groundwater pumping.” They pointed out that the report indicates fort-related pumping was already causing harm to the river by 2003, and that the peak effects are projected to occur around 2050.
The river, which snakes north from the Mexican border, nourishes an oasis that provides habitat for more than 350 species of birds, many of which pass through to feed during migration. The forests and wetlands along the river are filled with animals from frogs to bobcats.
Over decades, as more wells have been drilled across the river valley, pumping has triggered declines in the aquifer in many areas, drawing away water that would otherwise feed the San Pedro.
Endangered species that survive along the river include a plant with slender leaves called Huachuca water umbel, as well as the southwestern willow flycatcher, western yellow-billed cuckoo and northern Mexican gartersnake.
Under the Endangered Species Act, Fort Huachuca is required to consult with the Fish and Wildlife Service to ensure it won’t jeopardize federally protected species.
‘The situation has gotten worse’
The conservation groups argued in the Dec. 3 legal notice that the 2014 opinion by the Fish and Wildlife Service authorizing the base’s pumping is no longer valid, and that because significant new information is now available, the government must conduct a new consultation.
The groups said their legal filing is the ninth challenge since 1994 to Fort Huachuca’s activities based on environmental laws.
Sandy Bahr, director of the Sierra Club’s Grand Canyon Chapter, said in a statement that federal officials “must ensure that groundwater pumping is reduced to levels that keep this unique wildlife corridor alive.”
Silver said multiple species are at risk of going extinct if the San Pedro River dries up. He said despite local officials’ pledges of working toward a water “balance” in the area — in which the amount of water recharging the aquifer would roughly balance out with pumping — the area’s water deficit has worsened since the early 2000s.
Silver acknowledged that Fort Huachuca has taken significant steps to conserve water on the base.
“On post, they committed to a balanced budget and they pretty much are there,” Silver told The Republic. “And they were counting on the locals, the city of Sierra Vista, Cochise County and Arizona Department of Water Resources to help out so that they could balance the water budget off-post. That’s not happening. In fact, that situation has gotten worse.”
He said if the federal government doesn’t remedy the situation, the groups are prepared to sue.
Reach reporter Ian James at ian.james@arizonarepublic.com or 602-444-8246. Follow him on Twitter: @ByIanJames
Environmental coverage in The Arizona Republic and on azcentral.com is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at environment.azcentral.com and @azcenvironment on Facebook, Twitter and Instagram.