As river flows decline and court-ordered spill
to gas caps comes to an end at eight Snake and Columbia River dams, fisheries
managers at the interagency Technical Management Team this week argued over how
“spill to the gas cap” should be defined.
Snow-melt throughout May and early June forced
spill at the dams to uncontrolled or involuntary levels, most of the time much
higher than was called for by the U.S. District Court in a decision in April
2017. With involuntary spill, total dissolved gas levels in each of the dam’s
tailwaters and in the downstream dam’s forebay exceeded water quality limits
set by Oregon and Washington.
Now flows and spill have dropped, which has
allowed the U.S. Army Corps of Engineers to resume spilling to court-ordered
state mandated total dissolved gas levels, known as gas caps – 120 percent TDG
in tailraces and 115 percent TDG in the downstream dam’s forebay.
A three-judge panel of the Ninth Circuit Court
of Appeals ruled April 2, 2018 in favor of an April 2017 U.S. District Court
injunction allowing more spring spill at four lower Snake and four lower
Columbia river dams. With the decision, spill to the gas cap began April 3 at
lower Snake River dams and at lower Columbia River dams April 10. The
additional spill through June 15 is designed to aid migrating juvenile salmon
While both fisheries and river managers at
this week’s TMT meeting, June 13, agreed that the Corps should continue gas-cap
spill right up to today’s deadline for the operation, June 15, when
court-ordered gas cap spill is to end, differences arose among some fisheries
managers and the Corps as to how aggressive the dam operating agency should be
when pushing up against state dissolved gas limits.
Higher than normal flows, spill and TDG that
plagued the spill cap operations in May have returned to manageable levels,
according to a presentation at TMT by Dan Turner of the Corps’ River Control
He showed recent lower Snake River spill
targets that did not always result in reaching gas cap limits. For example,
since June 6 TDG in the Lower Granite Dam tailrace has averaged about 116
percent, with a low of 115 percent and a high of 118 percent (upper gas cap for
tailwater is 120 percent), while the downstream forebay at Little Goose Dam was
as low as 110 percent (upper gas cap for forebays is 115 percent).
At McNary Dam tailrace TDG has been consistent
since June 8 at 118 percent, while forebay TDG at John Day Dam dropped to as
low as 109 percent June 12 and 13.
“There has been a lot of frustration about
spill not reaching the gas cap over the last week,” Paul Wagner of NOAA
Fisheries said at the TMT meeting.
“Last Tuesday we were in a declining
hydrograph transition from involuntary to voluntary spill,” Russ Kiefer of
Idaho Department of Fish and Game told TMT. “There is a pattern here where the
high TDG of involuntary spill has resulted in a delayed response by the Corps
to bring spill caps up to meet the current conditions.”
“The Corps team is working hard to do the best
at managing a difficult situation,” said Julie Ammann of the Corps. “Overall
we’re making an effort to meet spill caps at all projects. We need to meet, not
exceed, state water quality standards.”
“It seems more like an effort to not meet the
court order,” said Erick VanDyke of the Oregon Department of Fish and Wildlife.
“I hope to get back to maximizing spill and I hope the Corps will do that.”
Dave Statler of the Nez Perce Tribe said the
Corps should be aggressive as possible with spill caps. “I hope we don’t get to
a point where we’re too cautious and not exceeding the spill caps on any day.
“It’s easy to say ‘meet spill caps,’ but
everyone has a different interpretation of what that means,” Statler said.
“We’ve never strived to go over spill caps,”
Ammann said. “We have taken what we’ve learned this year and are trying to
apply it to our operations.”
(See CBB, May 4, 2018, “Maintaining
Court-Ordered Spill At Columbia/Snake Dams Without Exceeding Gas Caps Proves
According to Jim Litchfield, who represents
Montana at TMT, that state considers the gas cap a maximum upper limit. “It’s
not a target, it’s a limit,” he said.
“You can exceed 115 percent in forebays, but
the average needs to meet the target,” Charles Morell of the Washington
Department of Fish and Wildlife said of how he thought gas cap spill should be
We interpret it to meet, but not to exceed,
Turner of the Corps concluded.
-- CBB, June 8, 2018, “NOAA Fisheries Delivers
First Court-Ordered Spring Spill For Fish Report; Shows Complex Operations” http://www.cbbulletin.com/440890.aspx
--CBB, May 18, 2018, “Court-Ordered Spring
Spill Now Moot As High Columbia/Snake Flows Forcing Involuntary Spill At Dams,”
--CBB, April 13, 2018, “Court Ordered Spring
Spill For Fish Begins On Four Lower Columbia River Dams,” http://www.cbbulletin.com/440516.aspx
-- CBB, April 6, 2018, “Appeals Court Rules In
Favor Of More Spill For Juvenile Salmon, Steelhead At Columbia/Snake Dams” http://www.cbbulletin.com/440480.aspx
--CBB, April 6, 2018, “New Court-Ordered Spill
Regime Based On Dissolved Gas Caps Begins This Week,” http://www.cbbulletin.com/440479.aspx
--CBB, March 23, 2018, “Ninth Circuit Hears
Arguments On More Spill For Juvenile Salmon/Steelhead At Columbia/Snake Dams,” http://www.cbbulletin.com/440399.aspx
- CBB, December 8, 2017, “Briefs Filed In
Appeals Court To Expedite Challenge To Increased Spill For Juvenile Salmon,