May 20, 2020 (PORTLAND, WA) -- Northwest RiverPartners Urges Practicality and Transparency
Over EPA River Temperature Report for Columbia & Snake River Dams
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 spawning.
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.
Conflicting Research
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 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.
