[env-trinity] Eureka Times Standard 4 12 09

[Byron Leydecker]

For want of water: Another dry winter could push Trinity River too far


John Driscoll/The Times-Standard

Posted: 04/12/2009 01:23:56 AM PDT





California's drought may push the Trinity River close to crisis this year,
and it will take a lot of rain next winter to prevent that plight from
getting far worse. 

When Trinity Lake falls below a certain level, it may no longer be able to
provide the frigid water to the river that's needed to keep salmon and
steelhead healthy during a hot summer. Depending on whether the region sees
more rain this spring, the lake could be drained close to that critical
point -- but probably not until, fall when temperatures drop. 

It is this coming winter that may spell real trouble. Should the drought
continue, Trinity Lake won't fill up enough to meet demands on the system:
the diversion to the Sacramento River and the Central Valley, the
electricity that diversion produces, and fish in the river. What water there
is may be too warm to ensure that salmon are protected in the river, as
well. 

"It will be difficult to meet all the requirements next year throughout the
system," said Brian Person, area manager for the U.S. Bureau of Reclamation,
which operates the project. 

The Trinity River Division of the Central Valley Project was completed in
the 1960s to ship water to the Sacramento River, which is tapped for farms
in the San Joaquin Valley. Early on, the diversion was as much as 90
percent, leaving the Trinity's fisheries in jeopardy. After years of
deliberations and litigation, a federal record of decision was put in place
in 2001 that mandated the diversion be no more than 52 percent in an effort
to restore salmon and steelhead. 

That decision calls for a yearly determination on how much water should be
released down the river and when. Extremely wet years call for huge releases
of water in the spring meant to reshape the river and improve fish habitat,
while dry years are meant to provide enough cold water for spawning and
rearing needs. 

Last week, the Trinity Management Council, which makes that determination
based on a series of forecasts on snow and rain figures, classified the year
as a "dry year." That means 453,000 acre feet -- or 147 billion gallons --
is scheduled to be sent down the river, most of it during the spring. 

If there is no more rain this year, that and the diversion to the Sacramento
River will draw Trinity Lake down to about 600,000 acre feet by late fall.
That's not likely to trigger a problem this year. But with the lake that
low, it will take millions of acre feet of water flowing into the lake over
the winter to bring the lake up far enough to keep it from falling below
that level in the summer of 2010. 

It's happened twice before. In 1977, the lake was far below that
600,000-acre-foot level and thousands of fish at Trinity River Hatchery died
from diseases. In 1991, it dipped just below that level. The wetter years
that followed, however, replenished the reservoir. 

"You have to tackle these things on a year-to-year basis," said Mike Hamman,
executive director of the Trinity River Restoration Program run by the
Bureau of Reclamation. 

Some familiar with the complex operation of the project, however, are
concerned that there is no real contingency plan to deal with an extended
drought in the face of possible climate change. There are so many
operational and regulatory constraints on the project that balancing them
could be increasingly challenging in the future. 

Among them are that the bureau must make sure that the water released down
the river from Lewiston Dam is cold -- about 48 to 50 degrees -- in order to
protect fish. It also has temperature requirements on the Sacramento River,
and Trinity River water is used to help keep that river cold, too. 

The plumbing of the project creates problems for meeting those requirements.
Because water released to the Trinity River must first move through shallow
Lewiston Lake, where it warms up during hot weather, more cold water must be
released to dampen that effect. So summer flows of about 450 cubic feet per
second to the river require that 1,500 to 1,800 cfs be released into
Lewiston Lake. 

The warmer the water released from Trinity Lake, the more difficult it is to
keep that water cool. It may be possible to take water from the bottom of
Trinity Lake, where it's coldest, but that bypasses the power plant. Even
that won't be effective if Trinity Lake gets too low and too warm. 

Trinity River fisheries advocates say that the problem could be avoided by
keeping more in the lake each year, something they say the bureau is
reluctant to do. 

"There is no plan for the future to avoid a crisis," said Tom Weseloh with
California Trout. 

Weseloh said that the group of stakeholders that make recommendations on
operations recently suggested that the Trinity Management Council ask the
bureau how it intends to comply with a 1990 State Water Resources Control
Board order intended to protect the river. It demands that temperature
requirements must first be met on the Trinity River. 

National Marine Fisheries Service Arcata Area Office Supervisor Irma
Lagomarsino said that if the lake is drawn down to below that
600,000-acre-foot level, the Bureau of Reclamation must confer with her
agency and the U.S. Fish and Wildlife Service. But there is no hard-wired
process to follow beyond that, Lagomarsino said. 

Lagomarsino said that long-term discussions are necessary to address how
much water is flowing to the Sacramento River and the Central Valley, adding
that the diversion and river flows have exceeded the amount of water flowing
into Trinity Lake for the past two years, which may constrain the operation
of the system in the future. 

"All of this is risk management," Lagomarsino said. 

The current scenario is something that former Trinity County Senior Planner
Tom Stokely was warning about several years ago. Stokely now works with the
California Water Impact Network, and said that the bureau has a number of
regulatory issues that need to be cleared up before there is assurance that
the Trinity River is protected in dire circumstances. Included in those, he
said, are that the releases called for in the 2001 record of decision have
not been written into key water rights permits. 

"Until that's done," Stokely said, "the Trinity's cold water supply remains
at great risk." 

John Driscoll can be reached at 441-0504 or jdriscoll at times-standard.com. 

THE PROJECT: 

Trinity Lake, behind Trinity Dam, stores water from the Trinity River for
release through Trinity Powerplant. Downstream, Lewiston Dam diverts water
from the Trinity River, through the Lewiston Powerplant, into Clear Creek
Tunnel for the 11-mile trip through the Trinity Mountains. Water enters
Whiskeytown Lake through Judge Francis Carr Powerhouse. Some of the water
diverts from the lake into the Clear Creek Unit South Main Aqueduct to
irrigate lands in the Clear Creek Unit. The rest flows through the Spring
Creek Power Conduit and Powerplant into Keswick Reservoir in the Shasta
Division. From there, it goes through Keswick Powerplant, then south in the
Sacramento River. The Wintu Pumping Plant diverts irrigation water from the
Sacramento River into the Cow Creek Aqueduct and Unit.

 

Byron Leydecker, JcT

Chair, Friends of Trinity River

PO Box 2327

Mill Valley, CA 94942-2327

415 383 4810 land

415 519 4810 cell

 <mailto:bwl3 at comcast.net> bwl3 at comcast.net

 <mailto:bleydecker at stanfordalumni.org> bleydecker at stanfordalumni.org
(secondary)

 <http://fotr.org/> http://www.fotr.org 

 

 

 

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