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Finding Water for Columbia River Fish in a Low Flow Year by Staff Columbia Basin Bulletin, July 24, 2015

Most Comes From Canada Storage Reservoirs

Canadian storage reservoirs have provided the lion's share of water releases for the Columbia River Basin, and in a timely fashion, during one of the driest years in decades throughout the region.

"It's a message that folks should understand, that the Columbia River Treaty has provisions that provide for releases for the lowest-of-low streamflow conditions," said Tony Norris, operations planner with the Bonneville Power Administration. "And this year, (releases) came out coincident with the needs of fish."

An estimated total of 8.7 million acre feet is scheduled to be released through September, with about 5.7 million acre feet coming from Canada.

Even with U.S. reservoirs such as Hungry Horse and Lake Koocanusa in Montana drafting a maximum of 20 feet below full pool, under provisions of a salmon and steelhead biological opinion for the Columbia Basin for dry years, U.S. storage will provide just about 3.2 million acre feet. The maximum provided for under the BiOp in the driest of years from U.S. storage is about 4.1 million acre feet.

Norris explained that the total U.S. flow target was arguably reached, but a large portion of it flowed downstream in the spring rather than being released from storage later in the summer.

"Since we have a low streamflow year, the U.S. portion of that streamflow augmentation (from storage) is diminished to a significant degree," Norris said. "There would normally be more U.S. storage released per the BiOp."

"We cannot make a dry year a wet year from storage," Norris said, adding however, that water managers can control and "shape" releases from storage.

This year, releases from Canadian storage to meet energy needs throughout the region were highly timely, totaling about 5.7 million acre feet of the total 8.7 million acre feet, with most of it coming in June and continuing into July.

"That's a notable number," Norris said, referring to the high proportion of water coming from Canada in relation to total storage releases.

About 3.2 million acre feet of the total releases are considered to be "Proportional Draft," a provision of the Columbia River Treaty with Canada that is designed to "meet firm energy needs during low streamflow conditions," Norris explained. "Fortunately, the release of water due to Proportional Draft occurred coincident with the needs of migrating salmon in the Columbia River."

Proportional flows, under the treaty, are separate from "flow augmentation" obligations for fisheries that amounted to about 4.7 million acre feet this year -- 3.2 million acre feet from U.S. and about 1.5 million acre feet from Canada. So the proportional flows from Canada under the treaty, and the timing of the flows, were significant.

"It's pretty rare to see proportional flows in June," Norris said. "It's fortunate this year, extremely fortunate, that these releases occurred during juvenile salmon migration."

Out of the total 8.7 million acre feet of storage releases, flows in June totaled 2.4 million acre feet while flows in July totaled 3 million acre feet. Aggregate storage releases are projected to drop sharply to 1.5 million acre feet in August and .5 million acre feet in September.

Those numbers include flow augmentation for the Upper Snake River Basin, which is not related to Canadian proportional flows. Total augmentation flows for the Upper Snake River Basin are expected to amount to 427 thousand acre feet.

Norris and other water managers note that estimates for flow augmentation will likely be adjusted as releases continue through the summer.

Related Pages:
Count the Fish Sockeye return counts from 1977 onward

Snake River Sockeye Life-Cycle: Returns Enhanced By Lipid-Rich Ocean During Smolts' First Year Columbia Basin Bulletin, 1/16/15
First Snake River Sockeye Reaches Sawtooth Basin; Fish Trapped At Lower Granite Taken to Hatchery by Staff, Columbia Basin Bulletin, 7/31/15
Water Temps (near 68), Lower Flows Prompt Earlier Than Usual Summer Hydro Operations In Lower Snake by Staff, Columbia Basin Bulletin, 6/19/15
Hot Weather Forces Dworshak Flow Increase To Cool Lower Snake; Snake River Sockeye Passing Bonneville by Staff, Columbia Basin Bulletin, 6/26/15
Lower Granite Water Temps Go Above 68 Degrees; Returning Snake River Sockeye Stalling Through System by Staff, Columbia Basin Bulletin, 7/10/15
Warm Water Hitting Returning Sockeye Hard: NOAA Says Maybe 80 Percent Mortality For Upper Columbia by Staff, Columbia Basin Bulletin, 7/31/15
NOAA Fisheries Releases Snake River Sockeye Salmon Recovery Plan: 25 Years Of Actions At $101 Million by Staff, Columbia Basin Bulletin, 6/12/15

Related Sites:
Last of Dworshak Water For August? 400 Snake River Sockeye Between Lower Granite, Sawtooth Basin by Staff, Columbia Basin Bulletin, 8/14/15
Smoke, Lower Air Temperatures Keep Lower Snake Cooler; 33 Sockeye Make It To Redfish Lake Trap by Staff, Columbia Basin Bulletin, 8/28/15