Arizona's San Pedro River
In recent years, it's become apparent that the San Pedro River itself is very much in jeopardy. Adjacent to the river are Fort Huachucha, Arizona's largest military base, and the fast-growing city of Sierra Vista; the water demands of these communities are simply outstripping the river's supplies. The rise in groundwater pumping from the San Pedro aquifer has been accompanied by a drop in the underground water table. Without strict controls on groundwater pumping, the San Pedro will soon cease to flow year-round, and will eventually become just another dry wash. The cottonwood-willow forestslarger than those of the Rio Grande, and the Colorado, Gila, and Pecos Rivers combinedwill die, and biologists can only guess at the ripple effect this might eventually have on all the wildlife dependent on the river.
University of Arizona studies show that most people in southeastern Arizona agree that protecting the San Pedro is a good thing, at least in the abstract. This general consensus underwrote the 1988 congressional decision to set aside a 40-mile stretch of the river between Interstate 10 and the Mexican border as a National Conservation Area. But the NCA designation offers no protection against groundwater pumping, the main culprit threatening the river. The paradox is that the allure of the San Pedro and its wildlife is a big part of the reason people are flocking here to visit or live, but, at the same time, it is this uncontrolled growth that is killing the river.
Sierra Vista and Fort Huachucha are trying to reduce pressure on the San Pedro by conserving waterwith low-flow plumbing and strict irrigation limits, for exampleand by finding ways get water back into the aquifer. The communities are experimenting with technologies that capture storm water and recharge the aquifer with treated waste water. But these measures are not by themselves likely to save the San Pedro, and other ways of balancing the river's "water budget"including retiring irrigated agriculture in the San Pedro River Basin, curtailing the growth that is fueling the region's economy, closing Fort Huachucha, or importing water from other parts of Arizonaare highly divisive solutions, each making a loser out of some segment of the region's people. Further muddying the political waters is the fact that the river crosses bordersits dynamics in Mexico remain poorly understood, but there's no question that the biggest water user along the river is the world's largest copper mine, near the Sonoran town of Cananea.
To get involved with the rescue of the San Pedro River, check in with the San Pedro Alliance, an international coalition of organizations seeking permanent protection for the San Pedro River; you can find information at the Center for Biological Diversity.
Whenever I'm asked about birdinghow I can spend hours stock-still, ogling birds and incurring neck strainI reach back to that day on the banks of the San Pedro. My friend Erik is a wildlife biologist and long-time birder, and I'd been slightly bemused for years by his fixation with our winged friends. But not 15 minutes into our San Pedro walk, he dug his elbow into my ribs and nodded at the stream bank beyond. Arcing out and over the stream from the cottonwood branches was a brilliantly ruby-red and black bird, so luminously colored it seemed to be lit from within. "Vermilion flycatcher," he whispered. It flew an elegant intercept course toward some unseen insect, snapped it up, and neatly swung back into the cottonwoods. Erik and I wordlessly watched it for nearly an hour as it made one elliptical orbit after another out over the San Pedrofeeding; courting a female vermilion; occasionally stopping to preen, flick its tail, sing its high, reedy song. And now I think of that day as my "confirmation ceremony" as an amateur naturalist, and of the San Pedro as churcha nearly intact ecosystem whose diversity is often favorably compared with Costa Rica's.
Saving it is not going to be easy or painless. But if this river is indeed one of the world's eight "Last Great Places," as the Nature Conservancy opines, then the burden of protecting it should rest on not just Sierra Vista or a Mexican mining town but state and federal tax dollarsin other words, it is a responsibility that falls on all of us.
Details mentioned in this article were accurate at the time of publication