By Jamie Pittock
20/09/2005 - From its headwaters high up
in the Cascade Mountains of south-west Oregon,
the Rogue River meanders its way hundreds
of kilometres towards the Pacific Ocean. Out
here in the rugged American north-west salmon
is king, and the Rogue, together with its
tributaries, provides crucial spawning habitat
for several stocks of the commercially and
recreationally prized fish species.
"Salmon are up against a mighty creek
without a paddle as the Rogue River is plagued
with a thousand barriers that impede fish
migration," said Brian Barr, a fish ecologist
with WWF’s Klamath-Siskiyou office in Oregon.
"Breaking down some of those barriers
will be critical to their survival."
Salmon have a complex life history that makes
their survival truly remarkable. Young salmon
migrate from rivers and streams to the ocean,
spending as much as six years at sea before
returning as mature adults — some reaching
weights of 27kg. Once they migrate back to
the rivers and streams of their birth, they
spawn and then die.
While in freshwater, either as young or returning
adults, salmon face a deadly race as summer
approaches — evacuating the hot, lower river
areas to the cooler tributaries and mountain
streams (river temperatures need to be less
than 13°C for spawning and egg incubation,
while salmon will die if the water temperature
tops 18°C for prolonged periods).
And, if this wasn’t enough to worry about,
they also have to tend with multiple obstacles
along the way that prevent them from getting
to where they need to be.
Hitting the wall
The Rogue River was once one of the most productive
salmon rivers along the west coast of the
United States, but 1,200 barriers block their
passage, compromising current populations.
“Dams are the number one fish killer in the
Rogue River Basin,” Barr exclaimed.
“Hundreds of thousands of Chinook and coho
salmon and steelhead trout pile up against
them as they try to find a way past them all
year long.”
The first obstacle salmon come across when
starting their yearly migration from the Pacific
is the Savage Rapids Dam. Built in 1921, this
old, decrepit dam located 170km upstream from
the ocean still slows salmon down, and in
some cases, prevents them from reaching spawning
habitats up river. The 12 meter-high dam is
used solely to divert water for irrigation
— it provides no storage, flood control, or
hydropower.
But, hopefully this will change during summer
of 2007 when a US Federal court decree requiring
the Grants Pass Irrigation District to remove
the dam goes into effect, ultimately allowing
salmon to pass this section of the river without
hindrance.
"There is still a lot of work to do
to secure the millions of dollars necessary
to remove Savage Rapids Dam and the next two
dams located immediately upstream," said
Bob Hunter from WaterWatch of Oregon, a non-profit
river conservation group devoted to restoring
and protecting natural river flows in Oregon.
"Fortunately for the Rogue River, the
dam owners are working cooperatively to secure
the funds to move these great projects along."
The US National Marine Fisheries Service
and the Bureau of Reclamation agree that the
US$6 million it will cost to remove the Savage
Rapids Dam and install irrigation pumps is
the most biologically-sound way to restore
fish passage at the site.
In addition to Savage Rapids, there is also
a commitment to remove the Gold Hill Diversion
Dam, the salmon’s second major hurdle on the
Rogue River. This diversion dam, located only
24km further upstream, supplies the municipal
water source for the city of Gold Hill. WWF
is working with the city, local government,
state and federal agencies, and WaterWatch
of Oregon, to raise the US$2 million necessary
to remove this structure. Currently, Gold
Hill is installing a new water supply system
on the Rogue that will eliminate the need
for the diversion.
"As soon as the new water supply intake
is in place, the old Gold Hill dam will serve
no useful purpose and should be removed,"
said Craig Harper of the Rogue Valley Council
of Governments. "It’s an eyesore, poses
safety problems for people, and kills fish.”
Next on the list of dam removals is the inactive
Gold Ray Dam, just 5km up from Gold Hill.
Although it has a fish ladder that allows
salmon to climb up and over this five metre-high
structure, it does not meet minimum standards
for adequate fish passage. There are no plans
currently underway to address fish passage
at Gold Ray, but it is clearly the next likely
location to address salmon migration restoration
along the river.
Climbing the ladder
It’s an early June day and four huge spring-run
Chinook salmon are spied resting in the slack
water just upstream of the Gold Hill Diversion
Dam. A fungus is visible on all four of the
1.5 metre-long fish, with two almost completely
covered by the disease.
“These fish have battered their bodies so
badly with unsuccessful leaps against the
concrete of the Savage Rapids’ poorly designed
fish ladder and the Gold Hill Diversion structure
that the fungus will likely kill them before
spawning begins in September,” said Barr.
“The fish damage themselves and can become
exhausted in their search for a way over the
dams.”
Further on at Gold Ray Dam another salmon
attempts to leap from pool to pool up a steep
ladder. Water is spilling over the sides of
the ladder with flows far too great to create
the specific hydraulic conditions that would
allow the migrating fish to swim efficiently
through the structure and over the dam. As
a result, salmon appear to fail in their leaps
as often as they succeed, frequently getting
washed down a step in their exhaustion.
“While it is possible to build successful
fish ladders at smaller dams, each and every
barrier has the potential to damage these
salmon and delays them on their race upstream
to reach the safety of cool water before the
heat of summer stresses them, potentially
to their death,” Barr stressed.
“We can see the battered adult salmon migrating
up from the Pacific, but far greater numbers
of juvenile salmon migrating downstream over
the dams to the sea are killed by many of
these structures.”
Working up river
Even further upstream in some of the river’s
tributaries, WWF has been working with landowners
to remove smaller barriers, many less than
two-metres high that prevent migrating fish
from getting to where they need to spawn.
For the past two years, the global conservation
organization has provided some of the funding
needed to remove eight structures blocking
fish passage on Sucker Creek, restoring some
360km of river access for salmon to streams
where they spawn.
Restoring the river for salmon will also
help populations of other depleted and threatened
fish and wildlife species such as river otters.
Helping water users find environmentally-friendly
alternatives to dams is also an important
part of the work. For example, installing
pumps to replace dams prevents the diversion
of juvenile salmon out of the river system.
Replacing leaky canals with pipes can save
50–100 per cent of the diverted water during
the dry summer months.
“By the end of 2007, we hope to remove at
least 12 of the most important barriers to
fish in the Rogue River Basin,” said Barr.
“I’m looking forward to the day when Rogue
Basin salmon runs are restored to their former
grandeur. A healthy salmon run means a healthy
river for both people and wildlife.”
* Jamie Pittock is Director of WWF’s Global
Freshwater Programme
END NOTES:
• The four species of salmon are key species
for the entire Rogue River ecosystem, providing
a nutritious food source to a multitude of
animals – ranging in size from tiny songbirds
to the mighty bears of the region. Salmon
carcasses provide much-needed trace minerals,
assimilated from the sea, to relatively sterile
cold water streams.
• A WWF report – Rivers at Risk – identifies
the top 21 rivers at risk from dams being
planned or under construction, including the
Yangtze in China, the La Plata in South America,
and the Tigris and Euphrates in the Middle
East. The report also shows that over 60 per
cent of the world’s 227 largest rivers have
been fragmented by dams, which has led to
the destruction of wetlands, a decline in
freshwater species – including river dolphins,
fish, and birds – and the forced displacement
of tens of millions of people.
