Save Our Wild Salmon - Hot Water Report 2016 (7.26.2016)

SOS HwR

-- REPORT FOR JULY 26, 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.

Will you be on the river this summer? Do you have a story or photo you would like to share? Please send to Sam Mace.

This is a joint project of the Save Our wild Salmon Coalition, Association of Northwest Steelheaders, Columbia Riverkeeper, Idaho Rivers United and Sierra Club.

SPRING-SUMMER 2016 WATER TEMPERATURES AT LOWER SNAKE RIVER DAMS (4/1-7/24)

HWR.4.LSRD.GRAPH

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, this year's daily mean water temperatures are frequently considerably warmer than the average daily mean temperature collected over the last 1-8 years.

Notably, Ice Harbor Dam reservoir average temperatures continue to rise above the 68 degree mark and are now very close to reaching 70 degrees. Temperatures in the Lower Monumental Dam reservoir continue to hover around 68 degrees while temperatures at Little Goose and Lower Granite reservoirs are not showing consistent trends but average temperatures are close to - but currently under - 68 degrees.

SPRING-SUMMER 2016 WATER TEMPERATURES AT LOWER COLUMBIA RIVER DAMS (4/1-7/24)

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, this one also reflects consistently higher water temperatures so far this year, when compared to average daily mean temperature based on data collected over the last 1-20 years.

Notably, average temperatures at the four lower Columbia River dam reservoirs have continued their steady upward trend - and are now all above 68 degrees.

HWR.4.LSRD.TABLE

HWR.4.LCR.table

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. Between July 18 and 24, temperatures have exceeded 68 degrees Fahrenheit between 2 and 7 time in three of the four lower Snake River reservoirs. Temperatures in each of the lower Columbia River reservoirs have exceeded 68 degrees between 6 and 7 times.

Overall in the lower Snake River reservoirs, 68 degrees has been reached or exceeded 14 times this past week and 42 times so far this summer.

In the lower Columbia River reservoirs, 68 degrees has been reached or exceeded 27 times this past week and 57 times so far this summer.

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: EPA PRESSES NOAA TO THINK BIG TO COMBAT HOT RIVERS & POACHED SALMON: Earlier this spring, EPA's Daniel Opalski sent a letter to NOAA's Michael Tehan urging the agency charged with protecting the Northwest's wild salmon and steelhead to consider additional recommendations and actions to better protect at-risk fish in the Columbia and Snake Rivers from hot water events in the June and July. The EPA is concerned that NOAA's recommendations are limited to "micro-scale temperature improvements at specific dams" and believes that additional measures be considered that "focus on reducing the overall river temperatures" in June and July to improve adult and juvenile salmon survival.

68 degrees F (20 degrees C) is the threshold at which water temperatures begin to harm salmon. Sockeye salmon are particularly at risk as temperatures above 68 degrees result in alarming rates of mortality. According to Mr. Opalski, the Director of EPA's Office of Water and Watersheds, keeping temperatures below 68 in the Lower Columbia and Snake Rivers “would be beneficial for adult summer Chinook and steelhead survival as well and would also be beneficial to juvenile salmon and steelhead out migrating during this period.”

To combat high temperatures in the lower Snake River, the EPA proposed various mitigation measures to keep temperatures below 68 degrees. Included in these measures is a recommendation to evaluate the Dworshak Dam cold water release program. This program releases cool water into the Clearwater River just before it enters the lower Snake River upstream of Lower Granite dam. (The beneficial effects of this program can be seen in the graphs above that track daily average water temperature throughout the lower Snake River.)

The EPA also calls on NOAA to evaluate lower Snake River dam operations and asks for recommendations to maximize the impact of the cool water released from Dworshack through all four of the lower Snake River dams. As shown on the graph above, the cold water releases from Dworshack can have a significant effect on water temperatures at the Lower Granite Dam reservoir, but those effects taper the further downriver you go. The release of Dworshak's water appears to have little to no effect on temperatures at Ice Harbor dam.

You can read the EPA's letter to NOAA here.

LINKS TO 2016 HOT WATER REPORTS AND OTHER RESOURCES:

HOT WATER REPORT 2016: #1 - July 6

HOT WATER REPORT 2016: #2 - July 12

HOT WATER REPORT 2016: #3 - July 19

HOT WATER REPORT 2016: #4 - July 26

SELECT 2016 MEDIA COVERAGE, REPORTS AND OTHER DOCUMENTS

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)

POLICY: EPA Comments on NOAA Fisheries 2015 Adult Sockeye Salmon Passage April 2016 draft Report (May, 2016)