Friday, July 27, 2007

Drought causes ripple effect

Irrigators, wildlife and forests showing signs of severe water shortage

Express Staff Writer

Richard Sahli of Nampa casts a fly from a dry gravel bar on the Big Wood River just south of Ketchum. On Thursday, measured at the river gauge at the Bullion Street Bridge in Hailey, the river was flowing at just below 50 percent of normal for this time of year. Photo by David N. Seelig

Signs the Wood River Valley is in the clutches of an extended, multi-year drought are painfully apparent.

Throughout the Intermountain West, experts in water, forestry, wildlife and other disciplines are reporting signs of severe, prolonged dry weather.

The effects are everywhere. They include too little water to meet the needs of many southern Idaho irrigators, drought-stressed forests unable to fight off outbreaks of forest insects and wildlife pushed into valley bottoms from their normal summer ranges in the high, remote mountains.

It's an inevitable recipe for trouble that brings the region's elk, deer and black bears into conflict with humans.

River levels are just one of many measures indicating the severity of the situation.

As of Thursday, July 26, the Big Wood River flowed at a mere 143 cubic feet per second, the United States Geological Survey river gauge at the Bullion Street Bridge in Hailey indicated. That compares to a 91-year average flow on the Big Wood River of 305 cfs for the same date.

On the Little Wood River above Carey, water levels are no better. Measured at the USGS-maintained river gauge upstream from the Little Wood Reservoir near its confluence with High Five Creek, the Little Wood River flowed at 33 cfs Thursday. That compares to a 43-year average flow of 78 cfs for the same date.

The summer's water woes further complicate the already difficult job of Kevin Lakey, water master for District 37 and 37M in Shoshone, which has jurisdiction over the Big and Little Wood river systems.

Thus far this summer, Lakey has had to shut off all water rights in the Big Wood River drainage with 1884 priority dates and younger. Only those with priority dates ranging from 1883 through 1880—the oldest water right in the Big Wood drainage—are still receiving water at this time, Lakey said Monday.

Those with 1883 priority dates are receiving only 30 percent of their water rights, he added.

The situation would be even worse if those who hold the oldest 1880 water right in the valley—the Diamond Dragon Ranch west of state Highway 75 in the Bellevue Triangle area—hadn't elected to forego receiving their water rights this year, Lakey said.

"They have not called for that water this year," he said. "That means I can deliver all of the Diamond Dragon water to everybody else."

Lakey said if Diamond Dragon hadn't chosen to do this, "everybody else would have been cut off a month ago."

The extensive forests of the Wood River Valley, like many of those throughout central Idaho, are also showing signs of drought-caused stress and fatigue.

Drought-stressed trees are far more susceptible to outbreaks of forest-dwelling insects like the mountain pine beetle, the Sawtooth National Forest's Ketchum District Ranger Kurt Nelson said.

One only has to look north of the Wood River Valley in the Sawtooth Valley and Stanley Basin areas to see the red-needled handiwork of the 5-millimeter-long native insects.

Minus ample amounts of water, tree species like the lodgepole pine are unable to mount an adequate response to fight off the attack of the miniscule beetles, which bore through trees' outer bark into cambium levels. Non-drought stressed trees like lodgepole pine are able to muster a "pitch out" mechanism to eject beetles from beneath their bark, Nelson said.

But the trees must have adequate amounts of water to produce the resinous substance they use to eject the insects, he said.

"They are able to push the bugs out with sap flow as the bugs are boring in," Nelson said.

In the past few years, the beetle outbreak has spread into other areas adjacent to and along the perimeter of the Wood River Valley. A drive over Trail Creek Pass east of Ketchum and even farther into the Copper Basin area on the Salmon-Challis National Forest provides an excellent view of this ongoing outbreak.

Scattered throughout the lower lodgepole pine-dominated forests and up higher in stands of whitebark pine, the needles of an increasing number of trees have begun to turn red.

Also impacted by the drought are local wildlife species. During drought years, wild critters that depend on green forage to put on fat reserves that will carry them through the coming winter must descend into the valley bottoms when their high-country food sources dry up, said Randy Smith, wildlife manager for Idaho Department of Fish and Game's Magic Valley Region.

"This is the kind of year we see more wildlife in the valleys and more potential for wildlife conflicts," Smith said.

Black bears, for one, are a concern in years like this, he said. Dry conditions mean bears' normal food sources—especially berry crops—are either slim pickings or nearly non-existent.

This means homeowners need to be extra cautious to keep garbage cans locked up and keep dog food and bird feeders inside their homes, Smith said.

"This is a very important year for people to keep these kind of things put away," he said.

The drought also has the potential to impact something closer to home—one's wallet.

As water flows go down so too does the Idaho Power Co.'s capacity to generate electricity from their regional hydroelectric projects. This decreased generating capacity in turn impacts the power rates the utility passes on to its customers.

In years of decreased snowpacks, "rates will generally go up as they have this year," Idaho Power Co. Corporate Communications Specialist Russ Jones said.

On an annual basis, the company monitors Idaho snowpacks before submitting an application with the Idaho Public Utilities Commission requesting what electricity rates it will charge customers starting June 1 of each year. More snowpack means lower rates, and vice versa, Jones said.

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