Water Released To Aid Sturgeon Biologists Hope High Flows Will Lead To Spawning

Within a week or so, the amount of Kootenai River water flowing past Bonners Ferry, Idaho, will more than double to help endangered sturgeon.

More water is being released from behind Libby Dam in Montana in hopes it will prompt the giant fish to spawn. The sturgeon haven’t reproduced in 20 years since the dam was built and bottled up spring floods. “We haven’t put out this amount of water in a long time,” Wayne Wagoner of the U.S. Army Corps of Engineers said Wednesday.

State and federal biologists have asked the corps for several years to release more water in the spring. But the corps and the Bonneville Power Administration have balked, citing drought and the need to keep water behind the dam for winter power generation.

So, last September, the U.S. Fish and Wildlife Service listed the sturgeon as endangered. That means federal projects, such as hydropower dams, have to be operated so no harm is done to the fish while a recovery plan is being written.

In short, the biologists got more clout. Here’s what has been agreed upon for this year:

The flow at Bonners Ferry went from 7,500 cubic feet per second in late April to 15,000 cfs on May 1.

Next, the corps will send as much water through Libby Dam as its turbines can handle. That will start when the water temperature increases to 48 degrees Fahrenheit (possibly within the next week) or when fish start spawning (eggs will show up on mats strategically placed in the river).

The 20,000 cfs that pours through the dam will be joined by water melting into tributary streams.

“By mid-May, it should be up to 35,000 or 40,000 at Bonners Ferry,” said Bob Hallock of the U.S. Fish and Wildlife Service.

The flow will remain at that level for 42 days or until radio-tagged female sturgeon retreat from the spawning areas and head downriver.

Fish and Wildlife officials wanted 35,000 cfs for six weeks. But because one of Libby’s five turbines is being repaired, the dam can’t handle high enough flows to sustain that level this year.

Ironically, while Fish and Wildlife blames the spawning problem on hydropower operations, it is urging the corps to install more generators. That way, more water can be sent through the dam to help spawning.

Libby was built to house eight turbines. Three of those have sat in boxes since 1980, Wagoner said. They would cost $15 million to install.

During the high water, the corps will have flood engineers on hand to work with farmers who have land in the floodplain, Wagoner said. They’re concerned the high water will damage levees or pumps.

Although the corps doesn’t expect any serious problems, Wagoner said, “we’ll be ready for anything.”

The last time flows reached such high levels at Bonners Ferry was in 1991, when spring runoff was naturally high, he said.