A panel that helps manage federal hydro operations in the Northwest has approved a request to increase flows from Montana’s Libby Dam.
The move is in preparation for reducing flows this fall for work to make parts of the Kootenai River more suitable for endangered wild white sturgeon.
The Technical Management Team last week approved the request by the Confederated Salish and Kootenai Tribes that will allow work on portions of a 55-mile stretch of the river mostly upstream of Bonners Ferry, Idaho.
“We’re really excited to get this first project implemented,” Sue Ireland, director of the tribes’ fish and wildlife program, said.
Flows from the dam have been increased from 14,000 cubic feet per second to 16,000. The flow will be decreased in September so work can start in the river.
Officials said the project is a large-scale ecosystem restoration that will take 10 to 15 years to complete. Work includes stabilizing banks, increasing riparian vegetation and improving side-channel complexity.
Before Libby Dam, there were an estimated 10,000 Kootenai sturgeon. Fewer than 500 mature adults of spawning age remain.
The wild Kootenai River white sturgeon, a toothless beast from the days of dinosaurs, has a large head, armor-like scales, can reach 19 feet long and top 1,000 pounds. It takes 20 or 30 years for white sturgeon to mature and reproduce.
An isolated population of the bottom-feeding behemoths lives along a stretch of the Kootenai that passes through Montana, Idaho and British Columbia, Canada. The construction of Libby Dam in 1974 stopped the river from flooding Bonners Ferry, Idaho, but also prevented the high water flows that triggered the sturgeon to move upriver and spawn.
In recent years flows have been increased at certain times of the year to make conditions more favorable for spawning sturgeon. But the most recent project is different.
“Another thing about this project that we think is important is that it’s a habitat fix rather than flow only, which has kind of been the only approach in the past,” Ireland said.
Work this fall will last about two months and include equipment in the river channel. The work costing about $2.2 million is mostly being paid for through the Bonneville Power Administration’s fish and wildlife program that’s intended to mitigating impacts caused by federal dams.
“We’re going to need to de-water a portion of the main and by-channels,” Ireland said. “We will need to isolate that work area by building a small dam so we can do the channel work.”
Ireland said part of the work is intended to reduce sedimentation in the riverbed that has reduced the survival chances for sturgeon emerging from eggs.
Officials say survival of young sturgeon in the river appears to be nonexistent. The tribes have a hatchery program that produces sturgeon and puts them in the river to prevent the population from becoming extinct.