investigations are continuing to identify the extent and cause of a
65-foot-long crack across a Wanapum Dam spillway pier monolith, fishery
experts, engineers and others are scurrying to assure passage for
fast-approaching salmon spawners.
Grant County Public Utility District hydro project was rendered impassable for
adult salmon and steelhead when, following the Feb. 27 discovery of the crack,
the reservoir upstream of Wanapum was drawn down by roughly 26 feet to reduce
pressure on the fractured spillway structure.
current reservoir level of 541-545 feet elevation, the lowest it has ever been
since the dam went into operation in 1964, doesn’t allow water to pour into the
fish ladders that were built to allow upstream passage.
lowered reservoir also leaves a considerable fall from the top of the ladder
for fish, should they be able to ascend it.
remedies for both issues are nearly in place. Workers are currently installing
pumps in the dam’s two fish ladders and will install weirs and flumes to help
migrating fish navigate to the top of the ladders and then to the reservoir
behind the dam.
on the fish ladders is expected to be completed by April 15, which is the start
of the spring chinook salmon run. At the request of agencies and stakeholders,
Grant PUD now plans to initially trap fish at Priest Rapids Dam and haul them
in trucks before releasing them above Wanapum or Rock Island dams during the
first few weeks of the fish run while the effectiveness of the ladder
modifications are evaluated.
to the “left bank” fish ladder, where more than 80 percent of the fish pass, is
expected to be completed by this weekend or Monday, Grant PUD fishery biologist
Russell Langshaw told the Technical Management Team Wednesday. TMT is made up
of federal, state and tribal fishery and hydro experts. The panel meets to
discuss options for improving hydro operations in the Columbia and Snake river
systems to improve survival for salmon and steelhead.
stocks include wild fish that are listed under the Endangered Species Act, such
as Upper Columbia spring chinook salmond and steelhead that must get up and
over Wanapum to reach spawning grounds. ESA listed bull trout also pass up and
down. Also passing the dam are summer and fall chinook, sockeye and coho
salmon, fish stocks that are not ESA listed, as well as lamprey.
slides are expected to be completed at Wanapum’s two fish ladders within the
next three or four weeks. The slides are intended to provide a safer descent
for fish from the top of the fish ladder down to the lowered reservoir.
the request of agencies and stakeholders, Grant PUD now plans to initially trap
fish at Priest Rapids Dam – the next hydropower project downstream on the
Mid-Columbia -- and haul them in trucks upstream before releasing them above
Wanapum or Rock Island dams.
collected at the Priest Rapids adult trap would be hauled “at least around
Wanapum in the near term,” Langshaw said. That involves a road trip of about a
half hour one way. Grant PUD to start has identified four available trucks,
each likely to carry from 75 to 100 spawners, though Langshaw said some have
suggested as many as twice that number could be carried. Potentially as many as
10 tanker trucks could be employed.
time would be roughly doubled if fish are transported to above the Chelan
County PUD’s Rock Island Dam, the next dam upstream of Wanapum. Ladders are an issue
too at Rock Island because of the lowered Wanapum Reservoir.
County PUD is taking steps to ensure passage of juvenile and adult spring
chinook salmon can occur at Rock Island Dam.
working for Chelan PUD have made adjustments to the release pipe for the Rock
Island juvenile fish bypass system that monitors smolts heading to the ocean.
The PUD will be able to use its standard river flow and special spill gates for
juvenile salmon and steelhead migration.
work has begun extensions to the left and right bank fish ladders for adult
salmon heading upstream. The juvenile bypass was expected to be ready by April
1 and the adult fish ladders by April 15 for the returning chinook.
PUD was able to take advantage of a March 22-23 drawdown to assess needed
modifications for the fish ladders and the juvenile fish bypass at Rock Island
with Mid-Columbia PUDs, Bonneville Power Administration, the Bureau of
Reclamation and the Army Corps of Engineers means that river flows will be
modified in early April to allow Chelan PUD to do some critical work on the
fish ladder extensions.
will start modifying two entrances for the right bank (Chelan County side) fish
ladder, with planned extensions of 84 feet each that allows fish to access the
permanent ladder under low tailwater conditions,” said Keith Truscott, PUD
Natural Resource director.
the right bank ladder modifications are complete, efforts will turn to
modifying the entrance to the left bank (Douglas County side).” Truscott said
“With these modifications, and anticipating the usual high flows of spring
runoff to help raise the tailwater levels during the peak of the spring chinook
migration, as well as guaranteed flows of 45,000 cubic feet per second through
October 2014, we feel that we can adequately handle the record returns expected
year was a stellar year. A total of 13,725 spring chinook; 71,083 summer
chinook and 263,924 fall chinook were counted passing Priest Rapids on their
way upstream. The fall chinook total compares to a recent 10-year average of
40,496 adult fish; and the recent four-year average of 98,100.
sockeye count at Priest Rapids was 163,078 in 2013.
numbers could be even larger this spring, summer and fall. The predicted
sockeye return to the mouth of the Columbia is nearly double last year’s actual
return. The upriver bright fall chinook return is expected to approach 1
million, which would be a record.
drilling team has completed six investigative holes into the Wanapum Dam
spillway pier monolith No. 4 as part of the forensic examination of the fracture.
will resume after a larger platform is constructed on the monolith to support
the workers and their equipment. Windy weather has created delays in the
drilling process, according to a Monday press release from Grant. All work on
the monolith, which is only accessible by boat or crane, must stop in wind
gusts that are more than 35 miles per hour. The platform construction and
drilling is expected to take about three to four weeks without significant wind
delays. The drilling will help determine the geometry of the fracture and how
far it reaches into the monolith.
PUD has accelerated plans for boat launch improvements during the reservoir
drawdown, which decreases cost and environmental impacts by doing work in the
dry. New estimates show that the utility will save nearly $1 million for
improvements to the Kittitas Boat Launch and Frenchman Coulee recreation sites
near Vantage after competitive bids were submitted last week.
the work during the reservoir drawdown reduces estimated costs by approximately
50 percent. Grant PUD is also looking into the possibility of performing
similar work in other locations, pending approval from regulatory agencies.
Wanapum shoreline remains closed during the low-reservoir conditions because of
safety hazards and to protect culturally sensitive sites. Grant PUD expresses its
appreciation for the public’s patience and understanding.
additional information, visit:
the PUD also is working on ways to provide for recreational access to the Rock
Island reservoir during the coming summer months. Right now, only Wenatchee
Confluence State Park boat ramp is available for public use on the Columbia
River between Rock Island and Rocky Reach dams. The PUD is looking at what
modifications may be possible this season to ensure that one or more of the
ramps can remain open.
we don’t know right now is how the situation will look in August and
September,” said Truscott. “We have the benefit of a decent runoff this year,
so our river levels and the river flow should be sufficient through July if we
are able to keep the headwater behind Rock Island Dam at or above 609 feet
(above sea level).
engineers are working on detailed analysis that will be complete in the next
two to four weeks and it will tell us more. We also are working closely with
Grant PUD to see if the Wanapum reservoir level will change. There are a lot of
moving pieces at the moment.”
PUD encourages its customer-owners and visitors to follow updates about its
response to the Wanapum Dam situation by going to chelanpud.org and clicking on
“Wanapum Drawdown Response” in the upper right hand corner of the District’s
home page. Real-time data on reservoir levels and river flows are being
maintained there and Rock Island public boat ramp closures also are being