[music]
Narrator: Northern California's Trinity River is the largest tributary to the Klamath River.
The Trinity River makes up roughly one-quarter of the total drainage area of the entire Klamath.
On average, the Trinity is often as productive as the other three-quarters of the entire basin
in terms of naturally spawning salmon that return each year.
The Trinity River is born from the high mountains of the Klamath Region in Northwestern California.
California State Highway 299 runs parallel to it for many miles along a spectacularly
beautiful canyon. It then flows through broad alluvial valleys and long, narrow gorges
before joining the Klamath River at Weitchpec. The Trinity River is a federally designated Wild
and Scenic River and offers a wide variety of recreation opportunities. It offers abundant
fishing, rafting, and kayaking options and is a critical resource to local communities. It also
provides vital drinking water and agricultural water to both local and nonlocal users.
The Trinity River feeds all of the diverse fishing communities.
Tribal fisheries, commercial, and sport fishers all reap from the bounty of the Trinity River.
The Trinity River is also home to one of North America's most notable large river restoration
programs: the Trinity River Restoration Program. This multi-agency eight-member partnership
is responsible for the complex task of rehabilitating the 40 miles of fish habitat
downstream of Lewiston Dam to the north fork of the Trinity as well as collaborating on the flow
regime from Lewiston Dam. [music]
This reach of the Trinity River has been altered by a long history of impacts.
Intensive gold mining began in the 1850s and continued for over 100 years,
dramatically altering channel conditions. Industrial logging altered hill slope
conditions and increased erosion and sediment production to the river and its tributaries.
In the 1960s, the Trinity and Lewiston dams were constructed as part of the Trinity River Division
of the Central Valley Project as authorized by Congress. These dams blocked fish passage,
and for many years, diverted an average of 80 percent of the flow out of the basin.
Over the course of a century, multiple human impacts combined to upset the natural balance
that sustained salmon populations for hundreds of thousands of years.
It is now the responsibility of the Trinity River Restoration Program to restore that balance,
but in the context of a smaller river system that is fundamentally changed.
Historically, multiple runs of salmon, steelhead, lamprey,
and sturgeon supported tribal people along the Trinity River. Hoopa and Yurok people have fished
along the lower Trinity River for thousands of years, and they continue to fish today.
The Trinity River's fish provided sustenance and wealth to the river-based communities. The river
itself provided transportation and a pathway for important world renewal ceremonies. All of
this changed with the gold rush and the arrival of thousands of miners, settlers, and homesteaders.
The miners literally turned the river inside-out and upside-down. The changes were widespread,
extreme, and some still persist today. Along with the physical changes came political
changes. In the late 1800s, the Hoopa Valley and Yurok Indian reservations were established,
affirming the tribal trust responsibility of the US government.
The establishment of these reservations guaranteed both tribes a place to fish and a right to fish.
Today, the Hoopa Valley and Yurok tribes together have the right to take up to 50% of the total
harvestable surplus of fish destined to return to the Klamath-Trinity River. Since the 1960s,
salmon and steelhead runs have been impacted by a combination of factors.
Large dams have blocked access to one-quarter of the entire watershed
and 109 miles of critical spawning and rearing habitats, while water diversions to
the Central Valley Project took an average of 80 percent of the inflow from the reservoirs.
Meanwhile, intensive logging and agricultural practices, road construction, and land development
introduced unprecedented volumes of sediment to this mainstem Trinity River. With the reduction in
mainstem river flows, the increased sedimentation wreaked havoc on an already degraded system.
Pools filled with sand and gravel and spawning gravels were smothered with fine sediment.
These factors took an immediate toll on salmon and steelhead
populations. [music]
Years of collaborative research by scientists working with tribal,
state, federal, and local agencies resulted in the Trinity River Flow Evaluation Study of 1999.
The goal of this study was to determine how to restore the salmon and steelhead populations
of the Trinity River. The resulting record of decision, or ROD, provided specific measures and
guidelines to restore in-stream flows, fish and wildlife habitats, and gravel bed load transport.
It also created an organizational structure and facilitated a unique management partnership among
federal, state, tribal, and county governments, as well as community and environmental organizations.
The Trinity River Restoration Program's goals have remained unchanged since its inception,
but the Trinity Management Council adopted a new statement of the goals in 2019.
The long-term goals of the TRRP are to restore the form and function of the Trinity River;
restore and sustain natural production of anadromous fish populations in the Trinity
River to pre-dam levels; and to facilitate full participation by dependent tribal,
commercial, and sport fisheries through enhanced harvest opportunities.
The Program works within an important conceptual framework:
adaptive management. Like the name implies, adaptive management allows the management process
to evolve as new information becomes available. The goal of restoring the health and abundance of
fish in the Trinity River involves multiple steps. Most importantly, there has to be enough water
for fish at the right times for both juvenile and adult biological needs.
Juvenile salmon and steelhead need side channels and shallow edgewater habitats to maximize their
growth and ensure a safe haven from predators. [music]
Since 2005, three-quarters of the 47 planned rehabilitation projects have been completed.
There's a variable flow regime, where an average 50% of Trinity River's natural inflow
is available for restoration purposes; watershed restoration has abetted fine sediment impacts;
and sediment augmentation and flow management have recovered a more dynamic river channel.
In addition, some necessary modifications to human infrastructures have been completed.
Bridges, wells, and septic systems built when the river ran at 20 percent of natural flows
have been modified or moved in order to accommodate the increased flows.
Today, the Trinity River Restoration Program is on the way to implementing its mission
of protecting and restoring salmon and steelhead populations by restoring flows
and river processes that will provide optimum habitat for salmon and steelhead recovery.
Since the impacts of the dams and diversions were first recognized in the 1960s,
it has been a long process to create a collaborative approach to undertake one of the
largest river restoration programs in the country. Each year the program learns more from monitoring
and assessment efforts, and the adaptive management process continues.
Effectiveness monitoring provides feedback to rehabilitation site designers
to inform future restoration efforts and help facilitate adaptive management of the program.
Results of restoration activities are becoming tangible.
There's an increased trend in the number of Chinook Smolts that survive per adult spawner,
an increase in juvenile rearing habitat areas at channel rehabilitation sites,
and the restoration reach has been returned to a gravel bedded river with diverse
habitat areas for adult and juvenile salmonids. Like the logo says, restore, adapt, and improve.
[water flowing]