The Lewis River Hydroelectric Projects - PacifiCorp

Lewis River Interpretive & Education Plan
Today’s programs concentrate on artificial rearing environments: hatcheryreared
smolts are trucked below the dam and released, circumventing the
dangers of the turbines. Future plans call for the reinstatement of programs to
bring adult fish over the dam and release them to spawn naturally in the creeks
above and around the hydroprojects, with facilities to reduce turbine mortality
in outmigrating smolts.
The first steps toward that goal are currently being taken: annually about 2000
adult fish are captured in a fish trap at the base of Merwin Dam and released into
Swift Reservoir to spawn. Although these fish will not be able to establish a selfsustaining
population, their presence in the tributary streams (digging redds,
and ultimately decomposing) will help fertilize the streams and prepare them for
future runs.
Speelyai Fish Hatchery, owned and funded by PacifiCorp and Cowlitz PUD,
is located on Speelyai Creek, along the road that leads to Speelyai Park. Water
is supplied by springs in the lower part of Speelyai Creek (the waters of the
upper creek have been diverted into Yale Lake). This clean, cold water provides
excellent rearing habitat for salmonids. The Speelyai hatchery incubates and
rears spring Chinook, coho, rainbow trout, and kokanee for distribution to a
variety of sites, including further up the Lewis River.
Merwin Hatchery, owned and funded by PacifiCorp is located at the dam.
Here, young winter and summer steelhead, and rainbow trout are reared in
water which is temperature-regulated according to the depth from which it’s
drawn from Merwin Lake (deeper waters are colder, providing a better rearing
environment for some fish life stages).
Each year, Chinook, steelhead and coho are trapped as adults as they arrive at
Merwin dam and trucked to holding ponds at Speelyai or Merwin Hatchery. At
Speelyai Hatchery, Chinook and coho are held there and spawned in the fall; the
eggs are incubated in Speelyai Creek water and the young fish are reared first in
raceways and then in net pens (which can be seen seasonally in the vicinity of
Speelyai Bay). When they reach smolt stage, the young salmon are trucked below
the dam and released into the Lewis River. At Merwin Hatchery, steelhead
adults are kept in holding ponds until the late winter. Adults are spawned and
eggs incubated until the young fish are big enough to be transferred to outside
ponds for rearing to release size.
Kokanee are reared at the Speelyai Hatchery for release into Merwin Lake. These
landlocked sockeye salmon are not native to the Lewis River drainage, but were
introduced into the reservoirs to create a sport fishery in the early 1960s. There
is no self-sustaining population of kokanee in Merwin (although neighboring
Yale Lake has a self-sustaining population, there are not enough suitable
Sea Reach Ltd • 146 NE yamhill Street • Sheridan, OR draft 3 • November 2008 • page 82