For the week of November 12 - 18, 2003

Snake water storage
hits all-time low

2004 irrigation depends on good winter

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"When you look at the numbers, it’s hard to stay optimistic."

— DICK LARSON, Idaho Department of Water Resources

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By GREG STAHL
Express Staff Writer

As Idaho drifts into its winter wet season, the state’s water experts are bemoaning the upper Snake River reservoir system’s lowest storage levels ever recorded.

On Oct. 11, close to the end of the irrigation season, the eight-reservoir system hit 385,000 acre feet of storage water, only 9 percent of its total capacity. The previous record was in 1977, when only 386,000 acre feet remained at the end of the irrigation system.

Nearly half of the total 2003 carryover is held in Idaho’s Henry’s Lake and in Wyoming’s Jackson Lake. The remainder of the storage is spread out throughout the rest of the reservoir system, according to the Idaho Department of Water Resources.

"That’s what’s been driving it, the years of drought," said IDWR spokesman Dick Larson. "We’ve been using the carryover, using the carryover, and now the reservoirs are gone."

Larson said nearly all indicators are pointing to ongoing drought. The four-year running average flow for the Snake River near Heise is as low as it has ever been. This year’s well drilling applications—2,000 so far—are at an all-time annual high. Flows from springs are down. The Snake River Plain Aquifer is getting lower.

"When you look at the numbers, it’s hard to stay optimistic," he said.

In reservoirs, carryover water is used like money in a savings account to reduce the amount of new water that has to be captured before the next irrigation season starts.

"That is critical on the Snake River system, where irrigators are totally dependent on the annual snow received during winter for their irrigation water supplies," Larson said.

Long-range weather projections for the coming winter are not optimistic for any type of above average snowfalls, Larson added.

At Magic Reservoir on the Big Wood River, 13,500 acre feet of water are currently stored. The reservoir’s capacity is 191,500 acre feet, said Big Wood Canal Co. director Lynn Harmon.

Water managers say the storage shortfalls have forced them to focus almost exclusively on capturing and saving every drop of water in the system reservoirs, except when low flows would jeopardize fish populations in the system.

Outflows from Island Park, Grassy Lake, Ririe and Henry’s Lake reservoirs have been shut off. Water releases from American Falls and Palisades reservoirs have been drastically reduced.

The move means total storage water levels in the system are increasing about 8,500 acre feet per day. At that rate, the storage system will have about 1.5 million acre feet of water by April 1, which is about 36 percent of the system’s capacity.

"That figure virtually guarantees severe irrigation water shortages during the 2004 irrigation season," Larson said.

If conditions don’t improve, farmers won’t be the only Idaho residents impacted.

Wildfires could continue to persist, the rafting industry could take a downward turn and tourism in general could suffer.

"People tend to think about how water shortages affect our farmers," Larson said. "It spins out way, way beyond that."

 

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