ENVIRONMENT / WATER WAR : Snake River Dam Proposal Becomes Idaho Hot Potato : Conservationists and farmers battle a city seeking more cheap hydroelectric power.

Here in the heart of potato country, where the swift-flowing Snake River generates cheap electricity, people were both amused and scornful as they brushed aside Los Angeles County Supervisor Kenneth Hahn’s recent proposal to channel river water to parched Southern California.

Among themselves, though, Idahoans bicker fiercely over use of the Snake, which was named for its meandering 1,038-mile course.

At issue now is the city of Idaho Falls’ 1984 application to build a hydroelectric power plant and dam on the western fringe of this small (pop. 3,680) town.

The Federal Energy Regulatory Commission is expected to rule on the application this summer. For nearly six years, the project has provoked allegations of deception, greed and ecological disregard between Shelley and Idaho Falls, communities separated by seven miles of Interstate 15 in southeast Idaho.

“They’re trying to build an electrical empire when we don’t need more electricity,” says Gerald Jayne, president of the statewide Idaho Environmental Council.

Jayne and a throng of residents of Shelley contend construction of the power plant will do irreparable harm to eagles, waterfowl, otter, trout and numerous other species--as well as disrupt several potato farms.

In Idaho Falls (pop. 42,830), where nearly $1 million already has been spent on studies aimed at winning a federal permit, Councilman Wes Deist and others insist the hydro plant is an economical hedge against uncertain energy supplies of the future.

Southeast Idaho, shouldered on the east by the Grand Tetons, is both energy and environmentally conscious. On the one hand, thousands are employed in nuclear defense research at the Idaho National Engineering Lab. And nearby Arco claims to be the first city lighted by nuclear power.

On the other, the region sports a variety of game species and the Snake’s tributaries are internationally renowned.

Others have a stake in the river, too. Commercial barges weighted with commodities and potato farms irrigated with river water also trace their vitality to it.

Indeed, Shelley, whose high school mascot is the “Russet,” is the center of the largest potato-producing region in the nation’s leading spud state.

Ted Harder’s family has been growing potatoes on a 350-acre riverside farm since 1942. Twelve-foot high dikes for the proposed Shelley hydro plant would replace the shoreline homes of Harder and his son, Doug, who is gradually inheriting the family farm. The project’s canals would supplant their potatoes.

Like several neighbors, Harder says he is not budging and has refused Idaho Falls’ offer of $500 to allow biologists, engineers and others access to his land for studies crucial to obtaining the license to build the plant.

“There’s some things you sell and some things you don’t sell, some things you can’t put a price on,” says Harder, 58.

When Harder and others learned that Idaho Falls had designs on their stretch of the river, they organized Save Our Snake. Though Councilman Deist contends detractors are merely a small “vocal minority,” the group boasts nearly 200 dues-paying members and has been formally recognized as intervenors by federal officials.

Like many, Shawna Wardell, a mother of five who is president of Save Our Snake, says enough is enough. The Snake’s flow already is interrupted by two dozen power plants and dams including, she notes, Idaho Falls’ recently completed Gem State plant just four miles upstream from Shelley.

Idaho Falls has two other plants, and the city produces about half of the 530 million kilowatt-hours it uses annually.

The abundance means low rates. At 3 1/2 cents per kilowatt-hour, electricity for Idaho Falls residents is about as cheap as it comes. Los Angeles residents pay about 8 cents per kilowatt hour.

Idaho Falls’ Shelley application faces an uphill climb. Besides federal approval, state agencies also must give the green light. And two, the Department of Fish and Game and the Department of Water Resources, have expressed reservations about the project, estimated to cost $24 million to $40 million.