-- REPORT FOR AUGUST 30, 2016 --
INTRODUCTION: With weekly updates, The Hot Water Report 2016 tracks water temperatures, salmon survival and climate related developments in the Columbia-Snake River Basin this summer. The report is updated weekly - published here every Tuesday - from early July through September. Each week we will share the most recent temperature data from the Columbia-Snake Rivers, news stories on climate change and current conditions for rivers and fisheries, and share information on actions state and federal agencies and our communities can take to ensure safer, healthier rivers for salmon and steelhead. We will include first-person accounts from anglers, guides, scientists and citizens on the Columbia-Snake rivers this summer.
SPRING-SUMMER 2016 WATER TEMPERATURES AT LOWER SNAKE RIVER DAMS (4/1-8/30)
The graph above reflects water temperatures recorded in the lower Snake River reservoirs. The blue-toned lines reflect the average daily mean temperatures in each of the four reservoirs collected in the last 1-8 years, beginning on April 1. The red-toned lines reflect the 2016 daily mean temperatures at each of the four lower Snake River reservoirs since April 1. As one can see, earlier this season, daily mean water temperatures were frequently considerably warmer than the average daily mean temperature collected over the last 1-8 years. There has been considerably more overlap in these temperatures since approximately the middle of July.
Notably, temperatures in the Lower Snake River appear to be beginning to slowly decline. This of course is good news for stressed and endangered salmon and steelhead that are still moving through this reach of the river - upstream as adults or downstream as juveniles. Temperatures in the Lower Granite Dam reservoir are the lowest - still hovering around 66 degrees - and safe for salmon and steelhead. Temperatures in the reservoir behind Little Goose Dam are a little higher, but still at or close to 68 degrees. Further downstream in the reservoirs of Lower Monumental and Ice Harbor Dams - temperatures are now about 68 degrees. Ice Harbor Dam's reservoir still has the highest temperatures, but it is cooler this week than during the last 6 weeks.
SPRING-SUMMER 2016 WATER TEMPERATURES AT LOWER COLUMBIA RIVER DAMS (4/1-8/30)
This second graph above reflects water temperatures recorded in the lower Columbia River reservoirs. The blue-toned lines reflect the average daily mean temperatures in each of the four reservoirs collected in the last 1-20 years, beginning on April 1. The red-toned lines reflect the 2016 daily mean temperature at each of the four lower Columbia River reservoirs since April 1. Like the upper graph, earlier this season, daily mean water temperatures were frequently considerably warmer than the average daily mean temperature collected over the last 1-20 years. These temperature differentials have tightened considerably since approximately the middle of July.
Notably, temperatures in all Lower Columbia River reservoirs continue to read consistently above 70 degrees F. - at or above 72 degrees Fahrenheit. These sustained, high temperatures in the lower Columbia and lower Snake rivers are harming fish returning to the Snake River and its tributaries - with lethal and sub-lethal impacts.
These two tables reflect the previous week's high water temperatures in each of the eight reservoirs created by the lower Snake and lower Columbia River dams. On the lower Snake River between August 24 and 30, temperatures have exceeded 68 degrees Fahrenheit twice in Little Goose, five days in Lower Monumental reservoir and all seven days in Ice Harbor reservoir. Temperatures in each of the lower Columbia River reservoirs have exceeded 68 degrees every day. In fact, there were no readings in the lower Columbia below 70 degrees this past week. This week's overall high temperature recording - 72.32 in John Day pool - was more than 1 degree cooler than last week's high in the Columbia (73.58 degrees in the reservoir behind the Dalles Dam).
Overall in the four lower Snake River reservoirs, 68 degrees has been reached or exceeded 14 times this past week (the previous week was 16) and 124 times so far this summer.
In the four lower Columbia River reservoirs, 70 degrees has been exceeded every day in all four reservoirs for a total of 28 times this past week and 199 times so far this summer. Recreational fishermen have told us that while there are decent numbers of fish in the lower river, they are stressed by the high temperatures and not biting. Catch rates in recent weeks have been very low.
Salmon and steelhead begin to suffer harmful effects when water temperatures exceed 68 degrees Fahrenheit. The longer temperatures remain above 68 degrees and the farther the temperatures rise above 68 degrees, the more severe the effects, including: increased metabolism/increased energy usage, increased susceptibility to disease, reduced fecundity or reproductive potential, and/or death.
Temperature data included in these reports come from the USGS Current Conditions for Washington State. Graphs and tables were assembled by SOS Staff.
THIS WEEK ON THE RIVER: Scientists and river managers are paying increasing attention to how migrating salmon rely on cold water refuges, whether they be mainstream rivers, tributary rivers and streams, springs or other sources. Columbia Basin Bulletin ran this story last week looking at the latest research. Some of these cold water sources have been buried under reservoirs making them less accessible or inaccessible to stressed wild salmon and steelhead. Removal of the four lower Snake River dams would deliver multiple benefits, including speeding migrating smolts toward salt water and reducing water temperatures throughout the lower Snake River corridor. An additional benefit of a restored Snake would be making incoming springs, streams and rivers more accessible to migrating adult salmon, providing cool water stops where fish could rest and wait for lower temperatures when the region experiences heat waves. Providing cold water “breathers” for our imperiled wild fish populations will become ever more imperative as our climate warms.
Read the full CBB story here.
LINKS TO 2016 HOT WATER REPORTS AND OTHER RESOURCES:
SELECT 2016 MEDIA COVERAGE, REPORTS AND OTHER DOCUMENTS
MEDIA: Lawsuit Aims To Lower Columbia And Snake River Temperatures For Salmon (Oregon Public Radio, August 15, 2016)
MEDIA: Hot water poses ongoing threat to Columbia River salmon, groups say (Spokesman Review, August 15, 2016)
MEDIA: Reservoir Drawdown Could Spare Fish (Lewiston Morning Tribune, July 17, 2016)
MEDIA: Steps Taken To Cool Warming Lower Snake, Reduce Thermal Blocks As Large Basin Sockeye Return Heads Upstream (Columbia Basin Bulletin, July 1, 2016)
MEDIA: Columbia Basin Salmon/Hydro Managers Gear Up For Another Hot Summer: Will Sockeye Get Slammed Again? (Columbia Basin Bulletin, June 2016)
MEDIA: Middle Fork could regain role as salmon nursery (Idaho Mountain Express, May 27, 2016)
LAW: N.W.F et al v. N.M.F.S. - U.S. District Court Opinion rejecting the federal salmon plan for Columbia and Snake river salmon and steelhead (Note: The Court's lengthy discussion of climate change begins on page 86. May 4, 2016)
MEDIA: Last year’s heat wave doomed nearly all Okanogan sockeye salmon (Seattle Times, April 13, 2016)
REPORT: Data Request Drawing Down Lower Granite Reservoir to Better Meet Water Quality Standards for Temperature (Fish Passage Center, June 2016)
SELECT 2015 MEDIA COVERAGE, REPORTS AND OTHER DOCUMENTS
MEDIA: Preliminary 2015 Spring Juvenile Survival Estimates Through Snake/Columbia River Dams Dismal (Columbia Basin Bulletin, October 23, 2015)
MEDIA: Dead Salmon, climate change and Northwest dams (Seattle Times Guest Opinion, August 2, 2015)
MEDIA: Snowpack drought has salmon dying in overheated rivers (Seattle Times, July 25, 2015)
MEDIA: Biologists bring sockeye into Idaho on trucks to get them out of hot water (Idaho Statesman, July 2015)
REPORT: Restoring Wild Salmon: Power system costs and benefits of lower Snake River dam removal (NW Energy Coalition, August 2015)
SELECT PRE-2015 MEDIA COVERAGE, REPORTS AND OTHER DOCUMENTS
REPORT: Bright Future: How to keep the Northwest’s lights on, jobs growing, goods moving, and salmon swimming in the era of climate change (NW Energy Coalition, 2009)
REPORT: A Great Wave Rising: Solutions for Columbia and Snake River Fish in an Era of Climate Change (SOS, NW Energy Coalition, Sierra Club, 2008