Northwest RiverPartners Urges Practicality and Transparency Over EPA River Temperature Report for Columbia & Snake River Dams
Vancouver, WA, May 20, 2020 – A report released by the Environmental
Protection Agency on May 18 entitled “Total Maximum Daily Load (TMDL) for
Temperature in the Columbia and Lower Snake Rivers” outlines river
temperature limits and seeks public comment. The report is related to a recent
decision by the Washington State Dept of Ecology to add a river temperature
provision into an EPA permit for Columbia River Basin dams.
The TMDL is required because Washington and Oregon identified portions of the
Columbia and lower Snake Rivers as impaired because temperatures exceed the
states’ water quality standards. These temperature requirements are designed to
protect the beneficial uses in these waters, in particular salmon migration and
River temperatures are a significant concern. In 1994, due to record high
temperatures, approximately 466,000 adult fish perished in the undammed
Fraser River before reaching their spawning grounds. In 2015, a quarter of a
million Snake River sockeye salmon died during a heatwave. Large fish die-offs
were also recorded in Alaska last summer due to heatwaves.
Northwest RiverPartners supports efforts to protect salmon from extreme
temperatures but takes issue with the standards that have been set by
Washington and Oregon. The TMDL report clearly demonstrates that the water
entering the U.S. from Canada is already too warm ”by a substantial margin” to
meet the Washington state standard in the summer months. The same is true for
the water entering the lower Snake River dams from Idaho.
This means that the Washington and Oregon standards cannot be met,
regardless of the existence of the lower Columbia and lower Snake dams.
Given these conditions, the EPA notes the significant challenge of meeting the
water quality standards in Washington and Oregon and has suggested that the
states reconsider their respective standards.
While this is a sophisticated and often complex process between state and
federal entities, what remains clear is that the newly proposed burden for
regional hydropower operators is unrealistic, unworkable, and unfair to the
communities that depend on affordable hydroelectricity to help make ends meet.
As part of this report, the EPA attempted to estimate river temperatures with and
without dams in place. The agency also tried to allocate temperature
responsibility to each dam but acknowledged the task as difficult and imperfect.
The EPA’s model estimated that the dams can cool or heat water, depending on
the month and the air temperature condition. In general, the model predicted that
during the August-September period, dams cause river temperatures to exceed
established targets. It’s important to note, however, that the great majority of
salmon smolts and adults do not migrate during these peak temperature months.
Other studies have shown that the dams have a neutral or moderately positive
effect on water temperature. As an example, a 2002 peer-reviewed study
performed by Pacific Northwest National Laboratory showed that dams within the
Columbia and Snake river basins tend to moderate extreme water temperatures.
Again in 2002, researchers compared pre-lower Snake River dam measurements
of water temperature from 1955-1958 to measurements taken after the lower
Snake River dams were constructed. They found no evidence that river
temperatures had increased as a result of the dams, and instead appeared to
have remained unchanged or slightly lower, even though air temperatures had
increased. The team identified air temperature and flow levels as the biggest
influences on temperatures in the river.
Washington and Oregon’s decision to include river temperatures in their
permitting process threatens to needlessly reduce the availability of a carbon-free
energy resource and increase electricity bills for millions of customers. These
decisions could also directly contradict efforts by both states to reach their bold
clean energy goals.
That outcome would be a step in the wrong direction for the climate, for salmon,
and for the social welfare of the region.
About Northwest RiverPartners
Northwest RiverPartners (NWRP) is a member-driven organization that serves
not-for-profit, community-owned electric utilities in Washington, Oregon, Idaho,
Montana, Nevada, and Wyoming. We also proudly represent partners that
support clean energy, low-carbon transportation, and agricultural jobs.