The approach to the Devils River challenges the senses. Limestone and juniper-covered plains, in gray and muted green, stretch as far as the eye can see. In the landscape, there's little variety or change.
Then there's the river. Flowing for 65 miles, the Devils River is turquoise-blue. It spreads broad and lazy. It flows swift and shallow through mazes of cane. It collects its force into waterfalls and powerful rapids. And it's clean – the Devils River is the most pristine river in Texas.
How does this crystal river exist in an arid, rocky land? At the Rio Grande Research Center in Alpine, scientists are learning about the river's workings, and its vulnerabilities.
Beginning south of Sonora, the Devils River meets the Rio Grande at Lake Amistad, near Del Rio. The Devils is the eastern boundary of the Chihuahuan Desert. Here, the signature plants of the Big Bend – ocotillo, yucca, lechuguilla – mingle with the oaks and hardwoods of Central Texas.
Taylor Bruecher is a master's student at Sul Ross State University. Working with the school's Rio Grande Research Center and the staff at Big Bend National Park, she is studying the Devils River – and the springs that sustain it.
“There's Pecan Springs, which is on the Hudspeth Ranch, above Baker's Crossing,” Bruecher said. “That is pretty much the headwaters of the Devils. And then you have Finnegan Springs. You have Dolan Springs, on Dolan Creek. And then you have the springs at Rio Vista. Those are the main ones, and they provide about 80 percent of the base flow to the Devils River.”
These four springs emerge from the Edwards-Trinity Aquifer. One of the largest aquifers in Texas, the Edwards-Trinity stretches from the Permian Basin to San Antonio, and its springs feed the Pecos River and the Lower Canyons of the Rio Grande.
Bruecher is collecting samples from springs on the Devils River, and submitting these samples to a range of tests.
Using radiocarbon and tridium tests, Bruecher can assess the age of the water. While spring flows increase in wet years, Bruecher has found that much of the water is emerging after 10,000 years or more beneath the surface.
With isotope testing, Bruecher and other researchers hope to identify sources of recharge – the spots where rainfall migrates down to fill the river's springs.
The river's wilderness character, and its abundant large- and small-mouth bass, make it a paradise for canoeing, kayaking and fishing. Boaters can access the river from Texas Parks and Wildlife land, but permits are limited. Most of the area is in private hands. Bruecher says the commitment of local landowners has helped preserve water quality.
“It's in such a remote area,” Bruecher said. “The landowners are very, very private and very protective of the area, and I think that helps a lot with keeping it pristine. It's not very easy to get access to it. There's a little bit of agriculture around the Devils River, but not a whole lot. And it's mostly spring water – that spring water is really, really clean.”
But while water quality remains excellent, flows on the river are on the decline.
In his 1981 book Springs of Texas, Gunnar Brune identified 120 springs along the Devils River. Most of those springs no longer flow. Where visitors once floated rapids, they must now must drag their canoes.
Increased groundwater pumping and drought are the primary causes of declining water, Bruecher says. As the state's population grows, the pressures on the Edwards-Trinity Aquifer will increase. Bruecher notes that only 15 percent of rainfall returns to the aquifer as recharge. In this arid country, pumping can easily outpace the rate of recharge.
“I think just understanding how groundwater works, how aquifers work, is really important to keeping rivers flowing and water available for the population,” Bruecher said. “We're keeping our finger on the pulse. We're monitoring it, to see what is happening. If we get a head start, I think we have more of a chance of protecting it.”
At the crossroads of West and Central Texas, the Devils River is one of the great wonders of the state. Understanding its ways is a first step – to insure that the river's pure waters flow into the future.