Sunday, January 29, 2023

Stacked flow to replace sturgeon spill

| May 12, 2006 12:00 AM

BY ROGER MORRIS Western News Publisher

A last minute alternative to spill from Libby Dam for endangered sturgeon was approved Tuesday by the white sturgeon recovery team, it was announced Wednesday night at the annual Libby Dam operation meeting.

The U.S. Army Corps of Engineers will begin increasing releases from the dam to powerhouse capacity, about 25,000 cubic feet per second, within the next week to achieve what is being called "stacked flows." The 25,000 cfs from the dam is being stacked on peak low elevation runoff in streams and rivers between the dam and Bonners Ferry to provide needed flows for the white sturgeon to begin spring spawning. Flows will remain full powerhouse capacity for up to 14 days and will be followed by releases of up to 20,000 cfs.

The biological opinion for the recovery of the white sturgeon, and the final environmental impact statement for the VarQ management protocol at Libby Dam, called for powerhouse flows plus 10,000 cfs of spill in three out of the next 10 years and preferably the next four years.

Brian Marotz, fisheries mitigation manager for the Montana Fish, Wildlife and Parks, said the discussion about stacked flows has been ongoing for the past two weeks.

"If we did anything else, it would have been unconscionable," Marotz said. "It's been something FWP has been after for years."

The decision diffused the discussion at Wednesday night's meeting. Several homeowners who live on the river above Libby have been threatening to sue the Corps if they spill water for the sturgeon. Homeowners Terry Andreessen and John Johanson have been expressing concerns about damage to their property after an unintended 2002 spill event.

While the property owners are pleased with the decision to go with stacked flows, they said they are concerned about an unintended spill occurring in June due to the high level of the reservoir and potentially heavy runoff from a deep snowpack in the Canadian reaches of the Kootenai River drainage.

Cindy Henriksen, director of the Crops' Reservoir Control Center near Portland, said the 2006 is showing itself to be 100 percent of average for runoff. She operations at Libby Dam for the summer will look very similar to 2005, which was 90 percent of average.

"In 2006, you might see some similarities to 2005," she said. "We will increase to powerhouse capacity by next week. The outflow from Libby Dam this summer will average the same, from 20,000 to 25,000 cfs."

She said Lake Koocanusa should reach full pool and the reservoir will be drafted down 20 feet for endangered downstream salmon in July and August.

Kerry Berg, policy analyst for Montana's two representatives to the Northwest Power and Conservation Council, said the state will once again seek to spread out the salmon releases over the month of September, too. And the state wants to draft Lake Koocanusa down 10 feet and not 20 as recommended in the salmon biological opinion.

The combined actions would lower the flows in the Kootenai river below 20,000 cfs.

Bruce Measure, one of two representatives for Montana to the NPCC, had told Lincoln County Commissioners last month that the state was prepared to file a suit to stop the spill for white sturgeon.

Bob Hallock, biologist for the U.S. Fish & Wildlife Service, said the agency is open to information and alternatives that use lesser flows.

He called spill from Libby Dam a "gut-wrenching action" because the agency is aware of problems it causes native species in the Kootenai River, including the endangered bull trout.

The latest biological opinion for sturgeon is calling for habitat construction downriver of Bonners Ferry to help the sturgeon either reach more suitable reaches of the river for spawning or creates an more suitable habitat in the river. Work on the option has been ongoing for several years and involves the U.S. Geological Survey.

"We're looking a flow options until we get habitat projects done," Hallock said. "I think we're going to come up with a remedy that meets your needs here and for the folks around Bonners Ferry."

It's not know yet where the habitat construction will need an environmental assessment or EIS. And funding can come from either Congress or the Bonneville Power Administration through the NPCC.

Marotz said the habitat improvements proposed for the Kootenai River are on an unprecedented scale.

"We're not at all thrilled about spill," he said. "The habitat construction is going to be expensive but it's worth it because there won't be a demand for such things as spill."