Two requests to change management of the Kootenai River, the
third largest tributary of the Columbia River, received a cool reception from
fisheries managers at this week’s Technical Management Team meeting, and one of
those, a request to deviate from VARQ on the river was denied.
The Kootenai Tribe of Idaho and the U.S. Fish and Wildlife
Service asked permission from TMT to maintain low flows in the river at 6,000
cubic feet per second or less in September and October to accommodate habitat
improvement construction in the river.
Even in a low water supply year, TMT fisheries managers
worried the operation would reduce flows needed for fish migrations in the
lower Columbia River and will likely suggest revisiting the operation closer to
September after it knows more about water supply in Lake Koocanusa, which backs
up behind Libby Dam in Montana, and available flows.
A second request from the Service is to provide additional
water releases from Libby Dam to augment flows for sturgeon and bull trout
spawning. It received a warmer reception as the operation would increase flows
in the lower rivers.
Decisions for both of these Special Operations Requests
(SOR) were put off to next week’s TMT meeting, May 13.
A third operation request from the Service was to deviate
from VARQ, the flood control rule in the Kootenai River, by dropping stream
flows immediately from the required VARQ flow of 18 cfs to 13 cfs.
“This year is unique,” said the Service’s Jason Flory.
“There is a lot going on and not a lot of water.”
He said VARQ at 18 cfs is high considering this year’s
hydrologic conditions in which there is almost no risk of flooding on the
river. It would help fill Lake Koocanusa higher by an additional three feet and
push more available water from this month to June through August.
As it stands in this low water year, the reservoir could be
drafted to an elevation of 2,439 feet by the end of September, rather than the
2,449 that has occurred in recent years. Full pool is 2,459 feet elevation.
For more information, see CBB, May 1, 2015, “Low Water
Forecasts At Dalles Dam Will Impact How Much Montana Reservoirs Will Be Drawn
TMT denied the Service’s request, saying it needed the
output at Libby Dam now to provide more river flow further downstream in the
Columbia River to help pass migrating juvenile salmon at the dams.
“The consensus (among TMT fisheries managers), this year
particularly with low flows and McNary at 170 kcfs, which is not desired, is to
continue to move water downstream from Libby during the spring migration,” said
Paul Wagner of NOAA Fisheries. “We’re struggling to keep the flows up at McNary
and also to refill Coulee in June.”
Variable flow, or VARQ (Q refers to flow), flood control has
been in effect at Libby Dam since 2003. In 2009, the U.S. Army Corps of
Engineers signed a Record of Decision for the flood control plan.
Prior to the ROD, the dam would generally release high flows
from January through April in order to make space to capture the spring runoff
in May, June, and July. Because of the large amount of water drafted,
historically little water was released from May through July period to allow
refill of the reservoir.
During the draft season in a majority of years VARQ provides
less flood storage space than standard flood control in Libby's reservoir, Lake
Koocanusa. During the spring-early summer refill, water releases from the dam
will vary based on the year's April-August water supply forecast for the basin.
The water release adjustments compensate for the reduced winter reservoir draft
VARQ also helps by stabilizing flows downriver in all but
the highest water years by sending more water downstream in spring and early
The first SOR of the year for TMT came from USFWS and Idaho
Fish and Game requesting flows for sturgeon and bull trout.
Based on the 2006 Biological Opinion for Libby Dam
operations, the April to August runoff forecast of 5.4 million acre feet make
operations for Kootenai River white sturgeon a Tier 2 year, which allows for .8 million acre-feet of water to
be released, but all in one peak (in
past years with better water supplies, it has been a two-peak operation).
The operation is to provide sturgeon in the river with cues
to begin their upstream migration to staging areas, and when river temperatures
warm to move into spawning areas. “Overall, the goal is to provide conditions
that will enable sturgeon to migrate to, and spawn over, rocky substrates that exist
upstream of Bonners Ferry,” the SOR says. The timing is May into July.
The SOR is at http://www.nwd-wc.usace.army.mil/tmt/agendas/2015/0506_2015_USFWS_Libby_sturgeon_SOR.pdf.
The second SOR from the Kootenai Tribe of Idaho and USFWS is to provide low
flows of no more than 6 cfs in September and October to accommodate instream
construction of a habitat project near Bonners Ferry Island.
The project is the latest in a series of habitat projects
aimed at restoring nearly 50 miles of habitat downstream of Libby Dam at a
total cost of $30 million over the past six years.
The project, which will be done over two construction
seasons, includes construction of two islands on mid-channel gravel bars of
about 18 total acres, excavation of three 20 foot to 30 foot pools,
construction of two large and two smaller pool-forming structures, and bank grading
and revegetation, according to the SOR.
The SOR is at http://www.nwd-wc.usace.army.mil/tmt/agendas/2015/0506_2015_KRHRP_SOR_FINAL_April_27_2015_db.pdf.
TMT will act on SOR 2015-1 and 2015-2 at its next
regularly-scheduled meeting Wednesday, May 13.