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Idaho gets smart about water

Science helps state juggle water rights during dry times


It might seem like the wrong time to be optimistic about Idaho’s water. Five years of drought have set an all-time record for dryness. Despite the increasing water needs of cities, recreation and native fish, farmers still account for nearly 90 percent of the state’s total water use. Farm irrigation routinely causes some streams to go dry and aquifers to shrink.

Thousands of farmers are now arguing over who gets what from the state’s biggest pool of water, the Lake-Erie-sized Eastern Snake River Plain Aquifer, which stretches underground from Twin Falls to Yellowstone National Park. The farmers are divided into two camps — the surface-water users and the groundwater pumpers — and Lynn Tominaga, director of Idaho’s Groundwater Appropriators Association, says, "This (water struggle) is either going to bring us together, or drive us further apart."

Ironically, the farmer-versus-farmer struggle may actually be a sign of progress. A flurry of recent actions by the state’s water powers shows that Idaho, which began shaking off a long adolescence 10 years ago, may finally be reaching maturity when it comes to water management.

Admitting connections

Farmers began tapping surface water above the Eastern Snake River Plain Aquifer in the early 1900s, especially from the huge springs that gush from the Snake River Canyon walls at the aquifer’s western edge. Then, from the 1950s to the early 1990s, other farmers began drilling thousands of wells to pump groundwater.

The groundwater pumpers put more than a million acres into irrigation for potatoes, beets and grain, but caused declines in the flows of springs, streams and rivers (HCN, 2/20/95: No more ignoring the obvious: Idaho sucks itself dry).

Finally, the Idaho Department of Water Resources, which had basically ignored the connection between groundwater pumping and surface-water declines for decades, started acting like a grown-up. In the mid-1990s, it instituted "conjunctive" management, which treats the state’s farmers as part of a single, interconnected water system. The department formed groundwater districts to manage the well pumpers. It also set up a leasing system, so that water needed for farmers or for salmon migration can be leased from farmers who aren’t using all of their allotted water.

But the surface-water users continued to complain about shortages. Those holding senior water rights began to make "calls" — legal maneuvers demanding that the groundwater pumpers either cut back or compensate them with leased water.

In response, the Legislature and Gov. Dirk Kempthorne, R, took several more steps this year. According to Tominaga, they approved spending about $60 million over the next 15 years, to help launch the federal Conservation Reserve Enhancement Program in Idaho. That program is expected to match state money with $180 million of federal money, paying farmers to idle fields and hence reduce the demand for water.

The political leaders also agreed to an expensive settlement of the Nez Perce Tribe’s claims on the Snake River. And they arranged to bill groundwater users for some of the costs of the reforms (HCN, 3/7/05: Small tribe in Idaho weighs big water deal).

Idaho is looking realistically at water systems in a way not seen in some other Western states; for instance, Arizona does not acknowledge the interdependence of surface and groundwater. And Barbara Cosens, a law professor at the University of Idaho who has worked on water issues in Nevada and California, says, "In comparison to those states, Idaho is way ahead in recognizing the connection between surface water and groundwater, and acting accordingly." Idaho’s reforms and its newfound enlightenment about water systems are helping the state weather the severe drought.

Shaping policy with science

Idaho’s water management is increasingly based on science. University of Idaho researchers, working with a range of hydrologists, have spent eight years developing a sophisticated computer model. It predicts how water moves through the aquifer, and shows the effects of shutting down specific wells.

Karl Dreher, who has run the water department since the mid-1990s, uses this model to decide which specific groundwater pumpers should be held responsible for surface-water shortages. It also helps him determine how to respond to the recent water calls.

Both this year and last year, for example, trout farmers and big canal companies issued massive calls that threatened to shut down 40 percent of the aquifer’s wells. Those calls could have devastated southern Idaho’s economy. One was settled with a temporary compromise, but several others are yet to be decided.

Evaluating one of the biggest calls, Dreher concluded that about 1,300 groundwater pumpers owe two canal companies and five irrigation districts a total of 27,700 acre-feet of water this summer. They may owe up to 101,000 additional acre-feet later, depending on rainfall and other variables.

The groundwater pumpers will have to spend more than $2 million this year to lease water for the callers, Tominaga says. Much of that water will be leased from "high-lift" pumpers, who draw water hundreds of feet uphill from the bottom of the Snake River Canyon. And they are generally eager to lease or sell their rights: Sharp increases in electricity costs have made their operations marginal.

The groundwater pumpers are also figuring out ways to use less groundwater, in some cases by leasing surface water instead. And they’re anticipating buyout offers from the federal Conservation Reserve Enhancement program. With that money, Tominaga says, more than 60,000 acres could be disconnected from groundwater, to answer the current calls. Down the line, the total could reach 100,000 acres.

In all the recent activity, salmon have not been forgotten: In April, the state paid $24.5 million to high-lift pumpers, so 75,000 acre-feet per year can go down the river to aid salmon migration. That’s the first time the state has bought out farmers’ water rights.

Idaho’s water management still needs tweaking, especially to help the fish. Recent progress shows that the state is at least headed in the right direction, according to John Tracy, director of the Idaho Water Resources Research Institute. However, he cautions that translating scientific understanding into sound water policy may prove arduous: "It’s one thing to understand the physical system; it’s another to change water management to meet all these goals."

The author is the environmental reporter for the Idaho Statesman. HCN’s editor in the field, Ray Ring, contributed to this story.