Trinity River Restoration Program Overview

Briefing for 

CVPIA Annual Work Plan

Public Meeting

February 17, 2011
Confined channel near Douglas City

The Compelling Problem: 

Impacts of Trinity Dam on Natural Processes

Reduced access to 

floodplain & loss of 

critical habitat

Major declines in 

naturally spawning 

anadromous fish 

populations by mid1970s

Decades of low flows 

from the dam

Encroached riparian 

vegetation & fine 

sediment in upper 

40 miles
Program Goals and Objectives:

“System-Wide Change” – From Dam to Estuary

 Restore populations of naturally 

spawning salmon and steelhead to predam levels.

o Implementation:

• Natural and variable flow releases.

• Create sufficient suitable habitat through 

achievement of healthy river attributes.

o Science and Monitoring: 

• Predict, measure, and evaluate progress 

toward long-term program goals; use to 

influence short-term management actions.
Project Location:

Trinity River –

largest tributary 

of the Klamath River

112 river miles from 

Lewiston Dam to 

Klamath River confluence

Trinity River Basin 

3,000 sq. mi.

Sacramento

Primary TRRP Project Area

(40 River Miles)
Program Context: 

Statutory, Administrative & Legal Mandates

1955 –Trinity Division of Central Valley Project authorized 

1964 – Trinity/Lewiston dams completed and filled

1970s – Salmon populations decline significantly

1981 – Interior Secretary requires Flow Evaluation Study

1984 –TR Fish & Wildlife Mgt Act passed by Congress

1992 – CVPIA enacted by Congress, established 

340,000 AF min. flows
Program Context: 

Statutory, Administrative & Legal Mandates

1999 – Flow Study completed, basis for Preferred Alternative 

in EIS/EIR

2000 – Record of Decision signed 

2002 – Program Office opens in Weaverville

2005 – First unconstrained ROD flows released, 

first rehab site completed
Program Partners:

Key Players – Numerous & Diverse

TMC

(“Board of Directors”)

 Bureau of Reclamation

 California Resources Agency

 Fish & Wildlife Service

 Forest Service

 Hoopa Valley Tribe

• NOAA Fisheries

 Trinity County

 Yurok Tribe

• Big Bar Community 

Development Group

• Redwood Regional 

Audubon Society

• California Trout, Inc.

• Northcoast

Environmental Center

• Environmental Defense

• Friends of the Trinity

• Glen Colusa Irrigation 

District

• Tehama-Colusa Canal 

Authority

• Natural Resource 

Conservation Service 

• City of Redding Electric 

Utility

• Safe Alternatives for 

Forest Environment

• 6 Rivers Outfitters & 

Guides Association

• County Residents & 

Landowners

 Trinity County Resource 

Conservation District

• Willow Cr. Community 

Services District

TAMWG

(Federal Advisory Committee)

 Funding Recipients
Science and Monitoring

 Basis of the Science aspect of the Program

 Alluvial river systems are complex and dynamic. Our 

understanding of these systems and our ability to 

predict future conditions are continually improving. 

 Adaptive management is intended to not only monitor 

changes in the ecosystem, but also develop and test 

hypotheses about the causes of those changes, in 

order to promote desired outcomes. 

 Integrated Assessment Plan 

 Integrated Habitat Assessment Plan

 Online Document Library at www.trrp.net
Implementation

 Flows Releases / Floodplain Structures 

 Mechanical Channel Rehabilitation

 Sediment Management

 Coarse Sediment Augmentation

 Watershed Restoration

 Fine Sediment Reduction
Higher Flows: 

Five Water Year Types

12

“Mimic natural snowmelt”

“Inter-annual variability” Determined on April 8
5-year Moving Average of Deliveries from Trinity Reservoir

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1960 1970 1980 1990 2000 2010

River Valley 5 per. Mov. Avg. (River) 5 per. Mov. Avg. (Valley)

Central 

Valley

Trinity 

River
Bridge Replacement

Poker Bar Bridge, 2005

Four new river crossings 

provide safe access to 

over 120 homes during 

maximum fishery flows

Poker Bar Bridge, 2001

11,000 cfs

Floodplain Structures - Bridges

Two contracts; $10 million 

for planning, design, and 

construction; completed in 

three years
House Removal

The “Little Yellow House”: a 

limiting factor for high flows; 

purchased March 2005

May 2005 

7,000 cfs

March 2006 

Removal

May 2006 

10,000 cfs

11,000 cfs

8,500 cfs

Floodplain Structures - Other
Inside Pump House

Pump Houses

Unsealed 

Well

Approx. Water 

level (11,000)

Decks

Electrical Connections

Many Small Structures

Waiver of liability secured 

& recorded from over 120 

landowners for floodplain 

structure modifications, 

including domestic water and 

sewage disposal systems, at a 

cost of $1,600,000.

Domestic Wells

Floodplain Structures - Other
Mechanical Channel Rehabilitation

 Record of Decision

 Complete 44 bank rehabilitations and 3 side 

channels 

 Progress

 Completed Phase 1 (50% compete overall)

• Phase 1 actually included 16 bank rehabilitations 

and 12 side channels

• Duration: 2005 - 2010

 Phase 2 Planning is the focus in 2011

• Assumed to be a similar level of effort as Phase 1

• Duration: 2011 - 2015

Mechanical Channel Rehabilitation Summary

Rehabilitation Site # Sites

Dirtwork 

(CY) Gravel (CY)

LWD 

(Trees)

Mainstem 

Length 

(Miles)

Edge 

Treated 

(Miles)

Acres 

Treated

Construction 

Cost

Hocker Flat 1 83,000 0 0 1.0 1.0 26 $850,564

Canyon Creek 4 91,000 0 100 1.7 2.0 40 $1,160,383

Indian Creek 3 77,800 0 200 2.8 2.5 31 $1,647,560

Lewiston-Dark Gulch 8 56,900 10,700 200 3.7 2.5 42 $2,000,000

Sawmill 1 87,750 5,700 260 0.8 2.0 25 $2,056,780

Lowden Ranch 1 102,600 19,000 150

2.4 5.2 36

$4,900,000

Trinity House Gulch 2 32,300 3,500 50

Reading Creek 2 67,690 5,900 100

Phase 2 - TBD 4 - 8

Phase 2 - TBD 4 - 8

Phase 2 - TBD 4 - 8

Phase 2 - TBD 4 - 8

Totals 47 599,040 44,800 1,060 12 15 200 $12.6 M
Sediment Management

 Coarse Sediment Augmentation Goals:

 Increase the total quantity of coarse sediment stored 

in the Trinity River

 Place 10,000 tons of gravel in the upper river annually

 Achieve equilibrium between gravel additions and 

gravel transported out of the upper river

 Reduce reach-averaged median bed surface grain 

sizes to approximately 3-inch diameter particles to 

facilitate bed mobility and salmonid spawning 

 Fine Sediment Goals are addressed in 

Watershed Restoration activities
Coarse Sediment Augmentation

Calendar 

Year Gravel (Tons)

Total per 

Year

2003 Cableway 3,000 3,000

2004 0 0

2005 0 0

2006 Hatchery 2,400 2,400

2007 Hatchery 6,500 6,500

2008

High Flow Injections 3,500

21,600

Lewiston-Dark Gulch 18,100

2009

High Flow Injections 3,500

12,000

Sawmill 8,500

2010 

High Flow Injections 4,600

Lowden, Trinity House Gulch, 47,200

Reading Creek 42,600

Total through 2010 = 93,000 
Watershed Restoration

 Goals:

 Achieve a long-term reduction in the total quantity of 

fine sediment stored in the Trinity River between 

Lewiston Dam and the North Fork Trinity River by at 

least 250,000 cubic yards.

 Reduce fine sediment delivery to the upper river by 

10,000 to 20,000 cubic yards per year

 Annually transport as much or more fine sediment 

downstream as is delivered to the upper river from 

tributary watersheds. 
TRRP 2010 Accomplishments

 Restoration Fund

 Funded environmental mitigation such as riparian re-establishment, wetland 

enhancement, and associated reporting to regulatory agencies. 

 Placement of 3,000 cubic yards of spawning gravel at the Diversion Pool and 

Grass Valley Creek delta sites during the spring 2010 high flow event. 

 Funded five watershed restoration projects including: mitigation projects in areas 

of high sediment production, preventative maintenance to reduce the likelihood 

that high rates of sediment projection will develop in the future, sediment 

detention, enhancing fish passage at road crossings or other obstructions, and 

assessments for identifying and prioritizing the watershed activities that will most 

effectively improve aquatic habitat conditions. 

 Purchased 166-32 foot logs suitable for use as habitat structures or engineered 

log jams and 2,500 cubic yards of coarse sediment for future rehabilitation and 

coarse sediment augmentation projects. 
TRRP 2010 Accomplishments

 Water & Related Resources (W&RR) Fund: 

 Program Administration of the TRRP, including Weaverville field office, Trinity 

Management Council (TMC) member agencies and tribes, and the federal advisory 

committee Trinity Adaptive Management Working Group (TAMWG). 

 Construction of Lowden Ranch Area and Reading Creek Rehabilitation Sites in 

Lewiston and Douglas City. Over 200,000 cubic yards of material is being 

excavated and 28,400 cubic yards of coarse sediment is being placed along 2.4 

miles of the Trinity River. In addition, large woody debris (trees), boulders, willow 

clumps, etc. will be placed in the mainstem and constructed side channels for 

aquatic and geomorphic purposes. The project will improve approximately 5.2 

miles of edge habitat and 36 acres of floodplain surfaces. 

 Planning and engineering designs 60% complete for the next four channel 

rehabilitation sites. 

 Flow schedule planning and implementation complete for WY2010. 

 Ongoing monitoring/assessment tasks – approximately $4.0M obligated to conduct 

stream gaging, sediment transport, juvenile outmigrant and fry utilization surveys, 

adult run size (weirs), sport and tribal harvest, habitat assessment, juvenile/adult 

fish health, riparian vegetation and wildlife, etc. 
Hocker Flat – One Year Later










Planned 2011 Accomplishments

 Construct up to 3 channel rehabilitation projects

 Fund between five and ten watershed restoration 

projects

 Augmentation of up to 5,000 cubic yards of course 

sediment depending on water year type

 Flow scheduling and implementation

 Ongoing science and monitoring activities