Lower Snake River Juvenile Salmon Migration Feasibility Study

This contains the Final Feasibility Report/Environmental Impact Statement (Final FR/EIS), Executive Summary, and 21 Technical Appendices for the Lower Snake River Juvenile Salmon Migration Feasibility Study. All files are provided in pdf format and can be read using Adobe Acrobat Reader.

The U.S. Army Corps of Engineers spent seven years studying Snake River dam removal. The final environmental impact statement, released in 2002, evaluated four alternatives to help lower Snake River fall chinook get past the dams: 1) the existing condition; 2) maximum transport of juvenile salmon; 3) system improvements that could be accomplished without a drawdown and 4) dam breaching.

The study included engineering work; biological investigations (i.e., effects to salmon and steelhead, resident fish, and wildlife); effects on recreation, cultural resources, and water quality; and socioeconomic effects, including implementation costs, navigation, irrigation, and power. The development of an environmental impact statement and public involvement were also included in the study, both of which are essential to the National Environmental Policy Act process.

The independent peer-reviewed study concluded that dam breaching by itself would not recover the fish, would take the longest time to benefit fish listed under the Endangered Species Act and would be the most uncertain to implement of any of the alternatives. The study’s preferred alternative was major improvements to fish passage systems at the dams.

Final Feasibility Report and Environmental Impact Statement


Improving Salmon Passage

Record of Decision  



Front Matter

Abstract, Table of Contents, Acronyms and Abbreviations

Executive Summary

Executive Summary

Section 1


Section 2

Affected Projects and Programs

Section 3

Plan Formulation

Section 4

Affected Environment




Section 5

Environmental Effects of Alternatives

Section 6

Plan Selection and Implementation

Section 7

Regional Coordination and Public Outreach

Section 8

Compliance with Applicable Federal Environmental Statutes and Regulations

Section 9

Literature Cited

Section 10


Section 11

List of Preparers

Section 12

Distribution List

Section 13





Appendix A

Anadromous Fish Modeling

Appendix B

Resident Fish

Appendix C

Water Quality

Appendix D

Natural River Drawdown Engineering

Annex A

Turbine Passage Modification Plan

Annex B

Dam Embankment Excavation Plan

Annex C

Temporary Fish Passage Plan

Annex D

River Channelization Plan

Annex E

Bridge Pier Protection Plan

Annex F

Railroad and Highway Embankment Protection Plan

Annex G

Drainage Structures Protection Plan

Annex H

Railroad and Roadway Damage Repair Plan

Annex I

Lyons Ferry Hatchery Modification Plan

Annex J

Habitat Management Units Modification Plan

Annex K

Reservoir Re-vegetation Plan

Annex L

Cattle Watering Facilities Management Plan

Annex M

Recreation Access Modification Plan

Annex N

Cultural Resources Protection Plan

Annex O

Irrigation Systems Modification Plan

Annex P

Water Well Modification Plan

Annex Q

Potlatch Corporation Water Intake Modification Plan

Annex R

Other River Structures Modification Plan

Annex S

Potlatch Corporation Effluent Diffuser Modification Plan

Annex T

PG&E Gas Transmission Main Crossings Modification Plan

Annex U

Hydropower Facilities Decommissioning Plan

Annex V

Concrete Structures Removal Plan

Annex W

Implementation Schedule

Annex X

Comprehensive Baseline Cost Estimate

Appendix E

Existing Systems and Major System Improvements Engineering

Appendix F

Hydrology/Hydraulics and Sedimentation

Appendix G


Appendix H

Fluvial Geomorphology

Appendix I


Appendix J

Plan Formulation

Appendix K

Real Estate

Appendix L

Lower Snake River Mitigation History and Status

Appendix M

Fish and Wildlife Coordination Act Report

Appendix N

Cultural Resources

Appendix O

Public Outreach Program

Appendix P

Air Quality

Appendix Q

Tribal Consultation and Coordination

Appendix R

Historical Perspectives

Appendix S

Snake River Maps

Annex A

1934 Survey Drawings:

Drawings 1-11

Sheet Numbers 1 Through 11

Drawings 12-23

Sheet Numbers 12 Through 23

Drawings 24-35

Sheet Numbers 24 Through 35

Drawings 36-47

Sheet Numbers 36 Through 47

Drawings 48-59

Sheet Numbers 48 Through 59

Drawings 60-71

Sheet Numbers 60 Through 71

Drawings 72-83

Sheet Numbers 72 Through 83

Drawings 84-95

Sheet Numbers 84 Through 95

Drawings 96-107

Sheet Numbers 96 Through 107

Drawings 108-119

Sheet Numbers 108 Through 119

Drawings 120-131

Sheet Numbers 120 Through 131

Annex B

Pre- and Post-Dam Comparison Displays

Appendix T

Clean Water Act, Section 404(b)(1) Evaluation

Appendix U

Response to Public Comments