Northwest Hydropower News Archives 2010 & Older

Return to Previous PageLet’s be sure Shoshone Falls’ future is secure

By Editorial

Fifty years is a long time to repent in leisure.

So let’s make sure – very sure – of what we’re in for if the Federal Energy Regulatory Agency approves Idaho Power’s plans to replace two small electrical-generating turbines at Shoshone Falls on the Snake River, a change that would significantly alter the flow of water over the 212-foot cascade.

The Boise-based utility wants a half-century plant license rather than the current 30-year permit.

By 2015, a $100 million plan to replace the turbines with one large 64-megawatt unit would alter the face of the falls, ensuring a show in the spring but possibly draining them for much of the rest of the year.

That’s critical, because Shoshone Falls pumps millions of dollars annually into the local economy through tourism – and thousands more into the treasury of the city of Twin Falls.

The new plant would be capable of diverting five times as much water as it can today, a new maximum of 4,800 cubic feet per second. Idaho Power’s current license requires it to spill at least 300 cfs over the falls during daylight hours from April 1 through Labor Day.

Under the terms of the utility’s application to FERC, it would release larger weekend flows on Fridays from 4 to 8 p.m. and Saturdays, Sundays and Memorial Day from 9 a.m. to 8 p.m. The actual amount over the falls would vary depending on the river. The plant would be limited to 950 cfs until the falls reached 9,000 cfs, at which point the plant would gradually increase its diversions.

All of which means that more water would run over the falls in the spring and summer – peak visitor seasons – than the current license requires. But the larger flows will come at a cost – even during the peak seasons, when the number of days that the falls get more than 300 cfs would nearly be halved at best.

The effect would be even more pronounced during the rest of the year. During the remaining 7 1/2 months, the falls would be bone-dry.

The city of Twin Falls has signed off on the plan; the state Department of Parks and Recreation and the federal government’s National Park Service aren’t so sure.

Neither are we, and not because the water releases that Idaho Power proposes wouldn’t be adequate for the immediate future. This license – if FERC approves it this year – would run until 2060. The world – and south-central Idaho’s economy and hydrology – could change profoundly in that time.

Think not? Then consider what our neck of the woods looked like 50 years ago, in 1960. Shoshone Falls was at best a regional attraction and ditches and laterals dominated irrigated agriculture in the Magic Valley.

Nobody dreamed the Eastern Snake River Plain Aquifer might actually start to run dry some day, the concept of conjunctive management was arcane, and the notion of climate change didn’t cross anybody’s mind.

And when Twin Falls had 16,000 residents, few grasped the real-world consequences of explosive population growth.

NPS wants Shoshone Falls visitors be surveyed and tallied to monitor the effects of the project. Idaho Parks and Rec questions whether the environmental review recommended enough measures to make up for the diverted river. Those are legitimate concerns.

Whatever decision FERC makes on Idaho Power’s application will have major effects on the Twin Falls and regional economy until the end of this century.

FERC must get this call right.

Twin Falls, ID
March 16, 2010

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