On its 111-mile journey from Galena Summit to the Snake River near Hagerman, the Big Wood River is well used.
It supports one of the West's best trout fisheries and is exposed to varying applications and manipulations by other water users: thirsty wildlife, parched golf courses, hungry irrigation canals and farmland, sewage plant returns and electricity generation plants, to name a few.
But local hydrologists say they don't really know in a comprehensive way how those uses are affecting the quality and quantity of water, which is arguably the most precious resource in the West.
Despite more than two dozen studies on the Big Wood River and its aquifer, the Wood River Valley's three most educated hydrologists are asserting they still don't have a clear view to the big picture. That's something they hope to soon change.
Funds found for analysis
Local hydrologists Bruce Lium, Wendy Pabich and Lee Brown have voluntarily spearheaded an effort to comprehensively study local water in the hope that the previous studies, combined with new data, will help local planners and public officials make decisions that will preserve the precious resource. The study will focus on the most developed portions of the upper Big Wood River Valley, approximately from North Fork to Glendale Road.
On Wednesday, Jan. 19, the Blaine Soil Conservation District capped off funding of the preliminary stages of the comprehensive local water study, which Brown called "a study of studies."
The conservation district's board unanimously voted to pony up a $5,000 contribution. Blaine County agreed earlier this month to contribute $5,000, and the U.S. Geological Survey, which will conduct the study, will match the local money to pay for the $20,000 preliminary examination.
The initial $20,000 inquiry will produce an outline of what could, should and should not be included in the overall study, which in "very, very preliminary" estimates could cost around $200,000, Lium said.
Pabich, who worked with a group of MIT students several years ago to study nitrogen loading in the Big Wood system, said her work on that project revealed only that more research is needed.
"One of the many things that came out of that study was that there is not enough ground water data to really understand what the water quality looks like," she said. "This would focus more on the science, so there would be a basis to develop more of these tools."
Blaine County Planning and Zoning Commission Chairman Lawrence Schoen said that in two years working on the P&Z, he has come to realize the value such a study could have.
"Given all of the past studies and their diversity, there needs to be an update of that from the top of the watershed down," he said.
Armed with new knowledge the study could supply, valley residents may not get 10 to 20 years down the road and discover they wished they had had more information and had done things differently
"We've got 25 studies, but they're not showing us anything," Lium said. "This isn't just another study. It's taking that next step so we can take precautions that will adequately protect our water resources."
Wood manifests water needs
Between Galena Summit and the Hagerman Valley, the Big Wood tumbles down alpine valleys, flows swiftly through consumptive mountain towns and helps green the great irrigated desert below. It is one of the best trout fishing streams in the country.
The Big Wood, which joins the Little Wood River near Gooding to become the Malad River, is a microcosm of the West's water use, as the balance between preserving natural resources clashes with consumption and production.
"Water and quality of life go hand in hand in Idaho," Brown wrote in a Big Wood water study released in 2000. "This condition is especially true in the Wood River Valley, where the economic engines of recreational tourism and agriculture drive the connection between water, nature and human existence even harder."
The Big Wood is the thread that binds the Wood River Valley's communities. Homeowners and builders flock to its edges, and anglers seek its prized trout.
But there's more going on in the river and its aquifer than one might think by watching it slither through the valley.
Alpine snowfields feed the aquifer, which surfaces in various locations along the serpentine river. The first of the springs, a mossy patch in the Smoky Mountains, isn't far from where state Highway 75 bisects the mountains at Galena Summit. From there, the stream gradually widens until, in Ketchum, it is more of a river than a stream.
Between its source and Magic Reservoir, 56 miles downstream and 3,800 feet lower in elevation, 28 named creeks and rivers feed the steadily growing—and below Hailey, shrinking—Big Wood. The river's upper basin covers 881 square miles of rocky mountain terrain and high sagebrush desert.
Throughout this area, the river and its aquifer work in tandem to transport water as gravity and soil permeability dictate. The Wood River Valley's cities, in fact, sit on top of the slow-moving underground river of water.
Hulen Meadows, just north of Ketchum, is at the top of the food chain, so to speak. Residents of the suburban-style neighborhood have the first sizable crack at use of water that could otherwise flow into the Snake, 100 miles downstream.
Farther down the valley, in the towns of Ketchum, Hailey and Bellevue, the Big Wood and its underground aquifer are used extensively.
"Blaine County's consumption is high compared to the rest of the United States," reads Brown's 2000 report, "Hydrologic Evaluation of the Big Wood River & Silver Creek Watershed."
"The typical American's annual use nationwide is much lower and is usually between 160 to 180 gallons a day, in contrast to the upper valley where this figure ranges from 400 to 600 gallons a day."
Even so, the Wood River Valley, with all its golf courses, excessively manicured lawns and thirsty people, consumes only 3 percent of the entire upper river's water. Each year, an average 1.33 million-acre foot of water flows into the Big Wood River system. Each year, the Wood River Valley's municipalities draw 1,960 acre feet back out.
Magic Reservoir receives 223,000 acre feet from the Big Wood River channel, and 29,300 acre feet recharges groundwater beneath the sagebrush desert and lava fields of the Snake River Plain.
"Both human and non-human demands are placed upon moisture the moment it enters the watershed," Brown said. "Ultimately, these demands will consume about three-quarters of annual precipitation while the remaining quarter will pass through the system" and into Magic Reservoir.
Goal is to provide answers
Although hydrologists know bits and pieces about the Wood River system, they continue to maintain that the big picture is missing.
"Water quality (investigations) has focused on the shallow part of the aquifer," Brown said, providing an example of missing information. "We need to ask real dumb questions: Gee, are water tables going up, going down or staying the same if you control for precipitation? The answer to that is, we really don't know.
"Real fundamental questions like that, we can't answer unless we pull all of this information together."