For the week of July 11 - July 17, 2001

Good from the first drop

Water’s journey from summit not overnight

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By GREG STAHL
Express Staff Writer

From the time a snowflake lightly settles on Galena Summit to the moment the same water molecule tumbles into the Snake River in the Hagerman Valley, 18,000 years might pass — if the drop of water ever makes it that far.

On its 111-mile journey, the water is well used. It is exposed to varying applications and manipulations: thirsty wildlife, parched golf courses, hungry irrigation canals and electricity generation plants, to name a few. And the people along the meandering stretches of the Big Wood River are as diverse as water uses are.

Water is Mother Earth’s life blood. It feeds her animals, people and plants, and helps put food on tables and keep electric lights on at night. The Big Wood River, which originates high in the Smoky and Boulder mountains, and feeds a vast valley aquifer, is no exception.

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 ¾ which joins the Little Wood River near Gooding to become the Malad River ¾ 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," writes hydrologist Lee Brown in a Big Wood water study released last year. "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."

 

Hydrology at a glance

The Big Wood is the thread that binds the Wood River Valley’s communities. Home owners and builders flock to its edges. Anglers seek its prized trout, and reflective thinkers seek its soothing sounds to spur ethereal thoughts.

But there’s more going on in the river and its aquifer than one might think by watching it snake through the valley.

After landing on a snowbank at around 10,000 feet in the upper basin, a water molecule that remains in the river’s underground aquifer may finally trickle into Ketchum 13,392 years later, according to Brown’s research. Water that remains in the river channel travels at several miles per hour, but there’s a constant exchange between the river and the aquifer, making water molecule travel time difficult to quantify.

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 from 6 inches to 5 feet near Galena Lodge. In Ketchum, the stream is more of a river at about 40 feet wide.

Between its source and Magic Reservoir, 56 miles downstream and 3,800 feet lower, 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.

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.

On 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 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, writes Brown.

Each year, an average 1.33 million acre feet of water flows into the Big Wood River system. Each year, the Wood River Valley’s municipalities draw 1,960 acre feet back out.

Most of the river’s flow goes to naturally water or unnaturally irrigate forests, rangeland and crops at 985,000 acre feet annually. Silver Creek is the recipient of 91,100 acre feet via an underground aquifer that transports Big Wood water to the fishing Mecca’s springs.

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," says Brown. "Ultimately, these demands will consume about three-quarters of annual precipitation while the remaining quarter will pass through the system" and into Magic Reservoir.

 

No water, no people

"Water is life in the Wood River Valley. If we had no snow or rain it is clear the communities in the valley would not exist," Brown says.

Dave Willding, a fishing guide for Bill Mason Outfitters in Sun Valley, agrees.

"The one thing about water issues anywhere in the West you go is that water will only support a certain amount of people," says Willding, who’s been fishing local streams and tracking Wood River Valley water issues for 20 years.

The Big Wood River in the upper valley is an attraction for well-to-do home-owners, who seek the solace — and inevitable problems—of riverside lots.

"River front’s worth a lot more," Ketchum Realtor Dick Fenton says. "It’s pretty popular. Any waterfront’s popular."

But as the valley’s community grows and water use increases, Willding fears the population threshold is approaching.

"Developers and Realtors aren’t doing this place any favors," he says. "This valley could be nearing its capacity."

Water doesn’t only contribute to people’s ability to live here. It’s a significant part of the valley’s largest economic engine, tourism.

During winter, the Sun Valley Co. taps the Big Wood and its tributary stream, Warm Springs Creek, to blanket Bald Mountain with snow. Without artificial snow fed by the rivers, tourism would suffer, and without tourism, 36 percent of Blaine County’s jobs would either directly or indirectly take a hit, according to a recently completed economic study.

The Big Wood and Silver Creek, which the Big Wood feeds, are two of several Blue Ribbon trout streams in Idaho that attract anglers from all over the world. Without the rivers and their abundant trout the economic engine would suffer.

There’s "no doubt" that fishing contributes to local tourism, Willding says. "It’s vital in the summer."

But the argument for or against human inhabitation of the valley, with or without water, goes far beyond tourism, skiing or fishing.

This summer, all of the valley’s municipalities are implementing emergency regulations that restrict the times residents are allowed to irrigate their lawns. They’re also restricting acceptable uses.

Last winter’s diminutive snows left little runoff to feed the Big Wood and other Idaho river systems.

At Ketchum water superintendent Steve Hansen’s recommendation, the Ketchum City Council recently adopted an emergency water use ordinance, should water levels in the city’s storage tanks dip below levels needed to fight fires or to wet parched mouths.

The ordinance gives the city the power to implement restrictions on watering lawns and landscaping, and washing sidewalks and porches. Those are all activities that could be turned off this summer, if water forecasters’ dire predictions hold true.

 

Low water, fish mortality and 
new fishing regulations

The Big Wood is "one of the best fishing rivers in the West," Willding says. Its natural cycles, unregulated by dams in the upper valley, and a cobbled river bottom contribute to the abundant fish here.

In hot, dry summers like this one, however, the river’s dissolved oxygen levels slip, and fish can become easily stressed. Many will probably die.

"The real loss, and people won’t see it, will more than likely occur next winter," says Fred Partridge, Idaho Department of Fish and Game regional fisheries manager. "The fish will go into the winter with less habitat available, and they’re in poor shape because of the summer’s warm water temperatures."

Even during hot, dry summers, the Big Wood fishery is a relatively healthy one, in part due to controversial fishing restrictions Fish and Game implemented in 1990.

Fish and Game changed Big Wood fishing regulations to catch and release only, between the Sawtooth National Recreation Area boundary, north of Ketchum, and Greenhorn Gulch, about five miles south of Ketchum. The take limit down-stream of that point was lowered from six to two.

It was an issue that packed the Wood River High School auditorium with 300 people for a public hearing, but Partridge says the end result was worth the headaches of getting the restrictions implemented.

"We haven’t had to stock that stretch (from north of Ketchum to south of Hailey) for three years," Partridge says. "Populations are pretty much at the carrying capacity of the system. There’s been a definite boost."

 

A shrinking river

In the river reach from Hailey to Magic Reservoir, the water table alternates between rising above and falling below the river channel, but overall the Big Wood is clearly a losing stream for most of the distance, Brown says.

It is not uncommon for the river to run dry below Glendale Bridge, south of Bellevue, during peak irrigation months, only to re-emerge several miles farther south from springs or from waters contributed from an irrigation return canal.

Water is withdrawn from the Big Wood River in the lower valley by three means: evaporation, stream bed seeps and irrigation diversions.

In the early 1990s, the Hailey stream gauge measured 382,000 acre feet a year, yet only 223,000 acre feet exited the basin at Stanton Crossing (U.S. Highway 20), "underscoring the amount of water lost from the river south of Hailey," Brown states.

Water seeping through the river bed and into the aquifer between Hailey and Glendale Bridge comprises about 79,200 acre feet per year.

"No doubt some amount returns to the Big Wood River via springs and stream bed flow. However, most serves to recharge the Bellevue Triangle/Silver Creek aquifer. Put differently, 217 acre feet of water each day percolates down through the river’s porous stream bed and moves toward the southeast and Silver Creek."

Irrigation diversions are another means by which the river loses water. Headgates are usually opened in May and water is diverted through a system of unlined canals that deliver water to south county farmers and ranchers.

"Great variability exists on the amount of water diverted for irrigation from the river, usually depending upon snowpack and precipitation," Browns says.

In the early 1990s test year, 101,100 acre feet were transported from the river through four large canals, called District 45, Black’s Ditch, Glendale and Baseline.

This summer, the four canals, evaporation and river bed seeps completely drain the Big Wood, which promptly ends near Glendale Road, south of Bellevue, where a large earth and rock dam diverts water into two of the canals.

Water downstream of there continues to flow most years, because Magic Reservoir stores enough during spring and winter to turn flows on each summer, feeding a vast plain of sugar beets, potatoes, alfalfa and other cash crops.

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Next week: Greening the desert: The Big Wood River from Magic Reservoir to Gooding.

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