A.07.23._Attachment_6_Example_Lower_Snake_River_PSMP.pdf

U.S. Army Corps of Engineers Walla Walla District

Lower Snake River Programmatic Sediment Management Plan

Final Environmental Impact Statement

August 2014

LOWER SNAKE RIVER

PROGRAMMATIC SEDIMENTMANAGEMENT PLAN

FINAL ENVIRONMENTAL IMPACT STATEMENT

( ) DRAFT

(X) FINAL

Lead Agency. U.S. Army Corps of Engineers, Walla Walla District

Type of Action. Administrative

Abstract. This Programmatic Sediment Management Plan (PSMP) and Environmental Impact Statement (EIS) presents the U.S. Army Corps of Engineers’ (Corps) plan for managing sediment within the lower Snake River system to meet the authorized project purposes that are affected by sediment deposition. The Corps is preparing this EIS to evaluate a long-term plan for management of sediment accumulation that affects authorized purposes of the four lower Snake River lock and dam projects in southeastern Washington and north central Idaho. This EIS also addresses a proposed current immediate need action and regulatory review, consistent with the plan.

The purpose of the proposed action is to establish a programmatic framework to evaluate and implement potential sediment management measures to address problem sediment accumulation. The PSMP provides a long term plan to manage, and prevent if possible, the accumulation of sediment that interferes with authorized project purposes. The immediate need action to reestablish the navigation channel to the Congressionally-authorized dimensions will be consistent with the PSMP.

The Corps formulated a range of alternatives by identifying and evaluating sediment management measures, then assembling the feasible and effective measures into groupings based on how measures could be implemented. The alternatives are programmatic and describe broad categories of actions that could be implemented to meet the purpose and need. The Corps identified Alternative 7 – Comprehensive (Full System and Sediment Management Measures) as the preferred alternative. The alternative includes dredging and dredged material management along with other sediment and system management measures, and provides the Corps with a complete toolbox for addressing sediment that interferes with the authorized purposes of the four projects.

Final EIS. The final report was officially filed with the Director, Office of Federal Activities, U.S.

Environmental Protection Agency on August 15, 2014.

Comments. Comments on the final report are due on September 22, 2014, 30 days from August 22, 2014, the expected the date of U.S. Environmental Protection Agency’s publication of Notice of Availability in the Federal Register. Comments are to be directed to the following:

U.S. Army Corps of Engineers, Walla Walla District PSMP/EIS, ATTN: Sandra Shelin, CENWW-PM-PD-EC 201 North Third Avenue, Walla Walla WA 99362-1876 Phone: (509) 527-7265 e-mail: psmp@usace.army.mil

Further Information. Additional information on the Final Environmental Impact Statement and related documents also may be obtained from the above. The documents are also available on the Corps web site at www.nww.usace.army.mil/Missions/Projects/ProgrammaticSedimentManagementPlan.aspx .

Table of Contents Lower Snake River Programmatic Sediment Management Plan – Final EIS

August 2014 i

TABLE OF CONTENTS

Table of Contents ........................................................................................................................... i Executive Summary ..................................................................................................................... ix Acronyms and Abbreviations ...................................................................................................xxv

Section 1.0 Introduction ........................................................................................................ 1-1

1.1 Introduction to the PSMP EIS....................................................................................................... 1-1

1.1.1 Proposed Action ............................................................................................................... 1-3

1.1.2 Purpose and Need ............................................................................................................ 1-4

1.1.3 Programmatic EIS ............................................................................................................ 1-7

1.2 Corps Authorities, Directives, and Obligations ............................................................................ 1-7

1.3 Sediment and the Authorized Project Purposes of the LSRP ....................................................... 1-8

1.3.1 Sediment Interference with Existing Authorized Project Purposes ................................. 1-8

1.3.2 Corps Sediment Management Guidance .......................................................................... 1-9

1.4 Corps Management of Sediment in LSRP .................................................................................. 1-10

1.4.1 Sediment Accumulation Areas ...................................................................................... 1-10

1.4.2 Corps Sediment Management Activities ....................................................................... 1-12

1.5 Other Agencies’ Management of Erosion and Sediment ............................................................ 1-15

1.6 A Watershed Approach to Sediment Management Planning ...................................................... 1-16

1.6.1 Watershed Sediment Study Area ................................................................................... 1-16

1.6.2 Sediment and the Lower Snake River Watershed .......................................................... 1-18

1.7 Environmental Review Process .................................................................................................. 1-28

1.7.1 Steps in the EIS Process ................................................................................................. 1-29

1.7.2 Scoping .......................................................................................................................... 1-29

1.7.3 Public Comment on the Draft EIS ................................................................................. 1-30

1.7.4 Changes to EIS Content ................................................................................................. 1-30

1.8 Next Steps ................................................................................................................................... 1-31

1.9 Organization of this EIS.............................................................................................................. 1-31 Section 2.0 Alternatives ......................................................................................................... 2-1

2.1 Introduction ................................................................................................................................... 2-1

2.2 Alternatives Development and Evaluation ................................................................................... 2-2

2.2.1 Problem Identification ..................................................................................................... 2-3

2.2.2 Development of Management Measures ......................................................................... 2-4

2.2.3 Criteria Development and Measure Screening ................................................................ 2-9

2.2.4 Measures Retained for Further Consideration ............................................................... 2-11

2.2.5 Range of PSMP Alternatives ......................................................................................... 2-27

2.2.6 Alternatives Screening ................................................................................................... 2-37

2.2.7 Alternatives Removed from Further Consideration ....................................................... 2-38

2.2.8 PSMP Alternatives Evaluated in Detail ......................................................................... 2-41 ii August 2014

2.3 Current Immediate Need Action ................................................................................................. 2-41

2.3.1 Alternative 1 .................................................................................................................. 2-41

2.3.2 Alternative 5 .................................................................................................................. 2-41

2.3.3 Alternative 7 .................................................................................................................. 2-42

2.4 Corps’ Preferred Alternative ....................................................................................................... 2-44

2.5 Environmentally Preferred Alternative ....................................................................................... 2-44

2.6 Environmental Effects of Alternatives ........................................................................................ 2-45 Section 3.0 Affected Environment ....................................................................................... 3-1

3.1 Aquatic Resources ........................................................................................................................ 3-1

3.1.1 Plankton ........................................................................................................................... 3-2

3.1.2 Benthic Invertebrates ....................................................................................................... 3-2

3.1.3 Aquatic Plants .................................................................................................................. 3-4

3.1.4 Fish .................................................................................................................................. 3-4

3.1.5 Threatened and Endangered Species ............................................................................. 3-21

3.1.6 Current Immediate Need Action .................................................................................... 3-21

3.2 Terrestrial Resources .................................................................................................................. 3-23

3.2.1 Vegetation ...................................................................................................................... 3-23

3.2.2 Terrestrial Wildlife ........................................................................................................ 3-25

3.2.3 Threatened and Endangered Species ............................................................................. 3-29

3.2.4 Current Immediate Need Action .................................................................................... 3-35

3.3 Recreation ................................................................................................................................... 3-36

3.3.1 Recreation in the LSRP .................................................................................................. 3-36

3.3.2 Current Immediate Need Action .................................................................................... 3-40

3.4 Cultural Resources ...................................................................................................................... 3-41

3.4.1 Cultural Resources Property Types ............................................................................... 3-41

3.4.2 Cultural Resources in the Watershed Study Area .......................................................... 3-43

3.4.3 Current Immediate Need Action .................................................................................... 3-45

3.5 Socioeconomics .......................................................................................................................... 3-46

3.5.1 Population and Demographics ....................................................................................... 3-46

3.5.2 Environmental Justice Communities ............................................................................. 3-48

3.5.3 Transportation ................................................................................................................ 3-48

3.5.4 Rail ................................................................................................................................. 3-57

3.5.5 Roads and Highways ..................................................................................................... 3-58

3.6 Water Quality and Sediment Quality .......................................................................................... 3-59

3.6.1 Water Quality ................................................................................................................. 3-59

3.6.2 Sediment Quality ........................................................................................................... 3-62

3.7 Hydrology and Sediment ............................................................................................................ 3-66

3.7.1 Geomorphology and Sediment Transport in the Snake River Basin ............................. 3-68

3.7.2 Watershed Sediment Production .................................................................................... 3-70

3.7.3 Lower Snake River System and Sediment Transport .................................................... 3-82

3.7.4 Current Immediate Need Action .................................................................................... 3-94

August 2014 iii

3.8 Hazardous, Toxic, and Radioactive Waste ................................................................................. 3-96

3.8.1 Current Immediate Need Action .................................................................................... 3-97

3.9 Air Quality .................................................................................................................................. 3-97

3.9.1 Regional Air Quality Conditions ................................................................................... 3-97

3.9.2 Regional Greenhouse Gas Conditions ........................................................................... 3-98

3.9.3 Current Immediate Need Action .................................................................................. 3-100

3.10 Aesthetics .................................................................................................................................. 3-101

3.10.1 Current Immediate Need Action .................................................................................. 3-101

Section 4.0 Environmental Effects of Alternatives ............................................................. 4-1

4.1 Aquatic Resources ........................................................................................................................ 4-3

4.1.1 Alternative 1: No Action (Continue Current Practices) .................................................. 4-3

4.1.2 Alternative 5 (Dredging-Based Sediment Management) ................................................. 4-5

4.1.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-15

4.2 Terrestrial Resources .................................................................................................................. 4-23

4.2.1 Alternative 1: No Action (Continue Current Practice) ................................................. 4-23

4.2.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-24

4.2.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-26

4.3 Recreation ................................................................................................................................... 4-28

4.3.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-28

4.3.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-28

4.3.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-30

4.4 Cultural Resources ...................................................................................................................... 4-32

4.4.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-32

4.4.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-32

4.4.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-35

4.5 Socioeconomics .......................................................................................................................... 4-37

4.5.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-37

4.5.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-38

4.5.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-40

4.6 Water Quality and Sediment Quality .......................................................................................... 4-42

4.6.1 Alternative 1: No Action (Continue Current Practices) ................................................. 4-42

4.6.2 Alternative 5: Dredging-Based Sediment Management ............................................... 4-42

4.6.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-46

4.7 Hydrology and Sediment ............................................................................................................ 4-49

4.7.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-49

4.7.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-49 iv August 2014

4.7.3 Alternative 7: Comprehensive (Full System and Sediment Management Measures) ....................................................................................................................... 4-51

4.8 Hazardous, Toxic, and Radioactive Waste ................................................................................. 4-54

4.8.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-54

4.8.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-54

4.8.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-55

4.9 Air Quality .................................................................................................................................. 4-58

4.9.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-58

4.9.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-58

4.9.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-60

4.10 Aesthetics .................................................................................................................................... 4-62

4.10.1 Alternative 1: No Action (Continue Current Practices) ................................................ 4-62

4.10.2 Alternative 5: Dredging-Based Sediment Management ................................................ 4-62

4.10.3 Alternative 7: Comprehensive (Full System and Sediment Management

Measures) ....................................................................................................................... 4-64

4.11 Cumulative Effects...................................................................................................................... 4-67

4.11.1 Resources Considered .................................................................................................... 4-67

4.11.2 Geographic and Temporal Scope of Cumulative Effects Analysis ................................ 4-68

4.11.3 Past, Present, and Reasonably Foreseeable Future Actions and Implications for

Resources ....................................................................................................................... 4-70

4.11.4 Summary of Cumulative Effects of Past, Present, and Reasonably Foreseeable

Future Actions on Resources ......................................................................................... 4-85

4.11.5 Cumulative Effects of Alternatives ................................................................................ 4-86

4.12 Climate Change ........................................................................................................................... 4-93 Section 5.0 Compliance with Applicable Environmental Laws and Regulations............ 5-1

5.1 Federal Statutes ............................................................................................................................. 5-1

5.1.1 American Indian Religious Freedom Act (AIRFA) ......................................................... 5-1

5.1.2 Archeological Resources Protection Act ......................................................................... 5-1

5.1.3 Clean Air Act ................................................................................................................... 5-2

5.1.4 Endangered Species Act .................................................................................................. 5-2

5.1.5 Federal Water Pollution Control Act (Clean Water Act) ................................................. 5-3

5.1.6 Federal Water Project Recreation Act ............................................................................. 5-4

5.1.7 Fish and Wildlife Coordination Act (FWCA) ................................................................. 5-4

5.1.8 Fishery Conservation and Management Act of 1976 ....................................................... 5-4

5.1.9 Migratory Bird Treaty Act ............................................................................................... 5-5

5.1.10 National Environmental Policy Act (NEPA) ................................................................... 5-5

5.1.11 Native American Graves Protection and Repatriation Act (NAGPRA) .......................... 5-6

5.1.12 The National Historic Preservation Act (NHPA) ............................................................ 5-6

5.1.13 Pacific Northwest Electric Power Planning and Conservation Act (Northwest

Power Act) ....................................................................................................................... 5-7

August 2014 v

5.1.14 Pollution Control at Federal Facilities ............................................................................. 5-7

5.1.15 Rivers and Harbors Act of 1899 ...................................................................................... 5-8

5.1.16 Treaties with Native American Tribes ............................................................................. 5-8

5.2 Executive Orders ........................................................................................................................... 5-9

5.2.1 Executive Order 11593, Protection and Enhancement of the Cultural

Environment, May 13, 1971 ............................................................................................ 5-9

5.2.2 Executive Order 11988, Floodplain Management Guidelines, May 24, 1977 ................. 5-9

5.2.3 Executive Order 11990, Protection of Wetlands ............................................................. 5-9

5.2.4 Executive Order 12898 - Federal Actions to Address Environmental Justice in

Minority Populations and Low-Income Populations, February 11, 1994 ........................ 5-9

5.2.5 Executive Order 13007, Native American Sacred Sites, May 24, 1996 ........................ 5-10

5.3 Executive Memoranda ................................................................................................................ 5-10

5.3.1 Council on Environmental Quality Memorandum, August 11, 1990, Analysis of

Impacts on Prime or Unique Agricultural Lands in Implementing NEPA .................... 5-10

5.4 State Statutes ............................................................................................................................... 5-11 Section 6.0 Notice of Intent Coordination, Consultation, and Public Involvement ........ 6-1

6.1 Scoping ......................................................................................................................................... 6-1

6.1.1 Local Sediment Management Group ............................................................................... 6-1

6.1.2 Agency Scoping Workshops ............................................................................................ 6-2

6.1.3 Public Scoping ................................................................................................................. 6-2

6.2 Tribal Consultation ....................................................................................................................... 6-2

6.3 Agency Coordination .................................................................................................................... 6-4

6.4 Public Outreach and Comment on the DEIS ................................................................................ 6-5 Section 7.0 List of Preparers ................................................................................................ 7-1 Section 8.0 Distribution ......................................................................................................... 8-1 Section 9.0 References ........................................................................................................... 9-1 Section 10.0 Glossary ............................................................................................................ 10-1 Section 11.0 Index .................................................................................................................. 11-1

LIST OF TABLES

Table 1-1. Lower Snake River Projects ....................................................................................... 1-1 Table 1-2. Corps-identified Sediment Problem Areas in the Lower Snake River System ........ 1-11 Table 1-3. Partial History of Federal/Port Dredging in the Lower Snake River ...................... 1-12 Table 1-4. Studies Conducted in the Snake River System......................................................... 1-24 Table 2-1. Management Measures ............................................................................................... 2-4 Table 2-2: Measures Dismissed ................................................................................................. 2-11 Table 2-3. Management Measures Retained .............................................................................. 2-12 Table 2-4. Alternatives and Associated Measures ..................................................................... 2-29 Table 2-5: Range of Alternatives Screening .............................................................................. 2-39 Table 2-6. Environmental Effects Summary Table ................................................................... 2-46 Table 3-1. Anadromous and Resident Fish Collected in the Lower Snake River 1 .................... 3-5 vi August 2014

Table 3-2. ESA-Listed Anadromous Populations Present in the LSRP .................................... 3-21 Table 3-3. Number of Terrestrial Wildlife Species Known to Occur in the Watershed Study Area

.................................................................................................................................. 3-26 Table 3-4. Lower Snake River ESA-listed Species (Threatened, Endangered, Proposed, Candidate) ................................................................................................................ 3-29 Table 3-5. Partial Listing of Recreation Sites in the LSRP ....................................................... 3-37 Table 3-6. Total Recreation Visits and Visitor Hours at Lower Snake River Recreation Facilities

.................................................................................................................................. 3-39 Table 3-7. Watershed Study Area Population Projections by County (2010-2030) .................. 3-47 Table 3-8. Race and Hispanic Ethnicity of Population within the Watershed Study Area (2012) 3-

Table 3-9. Watershed Study Area Income per Capita by County 2000-2009 ........................... 3-48 Table 3-10. Lower Snake Pool Levels ....................................................................................... 3-49 Table 3-11. Lower Snake River Barge Facilities – Lower Granite Reservoir ........................... 3-50 Table 3-12. Lower Snake River Barge Facilities – Little Goose, Lower Monumental and Ice

Harbor Pools ............................................................................................................ 3-51 Table 3-13. Lower Snake River Barge Facilities – McNary Pool ............................................. 3-52 Table 3-14. Lower Snake River Navigation Lock Detail (tons) ................................................ 3-53 Table 3-15. Origin of Grain Shipped on the lower Snake River, by State ............................. 3-54 Table 3-16. Watershed Subbasins .............................................................................................. 3-71 Table 3-17. Sediment Accumulation in Lower Granite Reservoir, 1974 – 2010 ...................... 3-85 Table 3-18. Relative Contributions of Subbasins to Sediment and Sand Load at Lower Granite

Reservoir, 2009 – 2010 ............................................................................................ 3-85 Table 3-19. Historic Dredging Activities in the Lower Granite Reservoir................................ 3-88 Table 3-20. Corps-Identified Potential Sediment Problem Areas in the Lower Granite Reservoir and Adjacent Areas .................................................................................................. 3-89 Table 3-21. Historic Dredging Activities in Little Goose Reservoir ......................................... 3-90 Table 3-22. Corps-Identified Potential Sediment Problem Areas in Little Goose Reservoir .... 3-90 Table 3-23. Corps-Identified Potential Sediment Problem Areas in the Lower Monumental

Reservoir .................................................................................................................. 3-91 Table 3-24. Historic Dredging Activities in Ice Harbor Reservoir ............................................ 3-92 Table 3-25. Corps-Identified Sediment Problem Areas in Ice Harbor Reservoir ...................... 3-93 Table 3-26. Historic Dredging Activities in McNary Reservoir (Snake River Portion) ........... 3-94 Table 3-27. Corps Identified Potential Sediment Problem Areas in McNary Reservoir (Snake

River Portion)........................................................................................................... 3-94 Table 4-1. Alternatives and Associated Measures ....................................................................... 4-2 Table 4-2. Geographic and Temporal Boundaries of Cumulative Effects Area ....................... 4-69 Table 4-3. Reasonably Foreseeable Future Actions .................................................................. 4-80

August 2014 vii

LIST OF FIGURES

Figure 1-1. Lower Snake River Projects ...................................................................................... 1-2 Figure 1-2. Current Immediate Need Action Locations and Port Maintenance Sites ................. 1-6 Figure 1-3. PSMP Watershed Study Area ................................................................................. 1-17 Figure 1-4. Watershed Land Ownership .................................................................................... 1-18 Figure 1-5. Sediment Types ....................................................................................................... 1-19 Figure 1-6. Watershed Schematic of Subbasins ........................................................................ 1-20 Figure 1-7. Wildfire-affected Areas in Lower Granite Reservoir Watershed ........................... 1-23 Figure 1-8. Wildfire Area in the Lower Granite Sediment Yield Watershed ............................ 1-23 Figure 1-9. Percentage of Total Annual Suspended Sediment Load

October 2008-October 2011 .................................................................................... 1-27 Figure 1-10. Percentage of Total Annual Suspended Sand Load

October 2008-October 2011 .................................................................................... 1-27 Figure 2-1. Dredging Operation on the Snake River ................................................................. 2-13 Figure 2-2 . Disposal Site Placement on the Snake River ......................................................... 2-16 Figure 2-3. Schematic of Bendway Weirs ................................................................................. 2-17 Figure 2-4. Dike Construction ................................................................................................... 2-18 Figure 2-5. Dike on the Mississippi River ................................................................................. 2-18 Figure 2-6. Vegetation Filter Strip Surrounding Agricultural Area .......................................... 2-23 Figure 2-7. Gabion Baskets Installed for Slope Stabilization Along a Stream .......................... 2-24 Figure 2-8. Knoxway Canyon In-water Placement Site ........................................................... 2-43 Figure 3-1. Middle Ninety Percentile Migration Timing of Anadromous Salmonid Stocks at

McNary and Lower Granite Dams. Timing based on the minimum and maximum dates for the annual 5th and 95th percentile passage during the previous 10 years (2004-2013)................................................................................................................ 3-8

Figure 3-2. Snake River Grain Volume Originating by Reservoir (excluding McNary Pool) .. 3-54 Figure 3-3. Sediment Encroachment in 2009 at the Confluence ............................................... 3-67 Figure 3-4. Lower Snake River System Sediment Issues – Conceptual Diagram ..................... 3-69 Figure 3-5. Annual Average Streamflow, Salmon River at White Bird, Idaho ......................... 3-72 Figure 3-6. Annual Average and Annual Peak Streamflow, Snake River near Anatone, Washington .............................................................................................................. 3-75 Figure 3-7. Annual Average and Annual Peak Streamflow, Grande Ronde River at Troy, Oregon

.................................................................................................................................. 3-77 Figure 3-8. Annual Average Streamflow, Clearwater River at Spalding, Idaho ....................... 3-79 Figure 3-9. Lower Granite Dam................................................................................................. 3-83 Figure 3-10. Comparison of 1974 and 2009 Sediment Ranges at Snake River Mile 137.69 .... 3-84 Figure 3-11. Comparison of 1974 and 2009 Sediment Ranges at Snake River Mile 123.30 .... 3-84 Figure 3-12. Little Goose Dam .................................................................................................. 3-89 Figure 3-13. Lower Monumental Dam ...................................................................................... 3-91 Figure 3-14. Ice Harbor Dam ..................................................................................................... 3-92 Figure 4-1. Relationship of Precipitation and Sediment Yield ................................................. 4-97 viii August 2014

APPENDICES

Appendix A: Draft Programmatic Sediment Management Plan (USACE 2012a)

Appendix B: Investigation of Sediment Source and Yield, Management, and Restoration Opportunities within the Lower Snake River Basin (Tetra Tech 2006)

Appendix C: Upland Erosion Processes in Northern Idaho Forests (Draft Report), USFS (Elliott et al. 2010)

Appendix D: Enhanced Sediment Delivery in a Changing Climate in Semi-arid Mountain Basins: Implications for Water Resource Management and Aquatic Habitat in the Northern Rocky Mountains, USFS (Goode et al. 2011)

Appendix E: Evaluation of Sediment Yield Reduction Potential in Agricultural and Mixed-Use Watersheds of the Lower Snake River Basin (University of Idaho and Washington State University 2010)

Appendix F: Lower Granite Reservoir – Hydrologic and Hydraulic Investigations.

Appendix G: Public Involvement

Appendix H: Blank

Appendix I: Lower Snake and Clearwater Rivers Sediment Evaluation Report for Proposed 2013/2014 Channel Maintenance

Appendix J: Lower Snake River Programmatic Sediment Management Plan, 2013/2014 Navigation Maintenance Monitoring Plan

Appendix K: Snake River Channel Maintenance 2013-2014, Lower Snake River, PM-EC-2007- 0001, Biological Assessment

Appendix L: Clean Water Act Section 404(b)(1) Evaluation

Appendix M: Sediment Transport in the Lower Snake and Clearwater River Basins, Idaho and Washington

Appendix N: Fingerprinting Sediment Sources Using Neutron Activation Analysis, ICP-MS, and Isotope Analysis in the Lower Snake River Basin

Executive Summary Lower Snake River Draft Programmatic Sediment Management Plan – Final EIS

August 2014 ix

EXECUTIVE SUMMARY

Introduction

The Walla Walla District of the U.S. Army Corps of Engineers (Corps) has identified and evaluated sediment management strategies for the lower Snake River. Based on the analysis presented in this Environmental Impact Statement (EIS) and stakeholder and public comments, the Corps will adopt and implement a Programmatic Sediment Management Plan (PSMP) (see proposed PSMP in Appendix A) for management of sediment within the lower Snake River system to meet existing authorized project purposes.

As a part of its Congressional authorization, the Corps operates and maintains the navigation system on the lower Snake River, which is part of an inland navigation system from Lewiston, Idaho, to the Pacific Ocean and includes the Columbia River.

The Corps constructed four dams on the Snake River in Washington State (Ice Harbor, Lower Monumental, Little Goose, and Lower Granite) between 1961 and 1975. The Corps’ sediment management area includes the lower Snake River from the confluence with the Columbia River1 to the upstream limits of Lower Granite Reservoir, including the lower portion of the Clearwater River. For the purposes of this EIS, the sediment management area, including the four dams and their associated locks and reservoirs, is referred to as the Corps’ Lower Snake River Projects

(LSRP).

The existing authorized project purposes of the LSRP include commercial navigation, recreation, fish and wildlife conservation, and flow conveyance. Sediment accumulation in the lower Snake River can interfere with these authorized project purposes of the LSRP.

The Corps has historically used dredging as its primary method of removing accumulated sediment that interferes with the authorized project purposes of the LSRP. Dredged sediments were moved to and placed in areas where they would no longer interfere with the authorized project purposes, either in-water within the reservoirs or on upland sites.

Between 1999 and 2002 the Corps prepared a Dredged Material Management Plan (DMMP) EIS, which evaluated alternatives for managing dredged sediments in the LSRP. Following the September 2002 publication of the Record of Decision for the DMMP EIS, a group of environmental and fishing interests (collectively referred to as the “plaintiffs”) filed a lawsuit in November 2002, alleging compliance failures by the National Marine Fisheries Service (NMFS) with respect to the Endangered Species Act (ESA) and by the Corps with respect to the National Environmental Policy Act (NEPA). The U.S. District Court, Western District of Washington, granted a preliminary injunction, halting further action by the Corps. The Corps withdrew the

1 The lower Snake River between the confluence with the Columbia River and Ice Harbor Dam is within the reservoir formed by McNary Dam on the Columbia River.

x August 2014

Record of Decision and in 2005 prepared an EIS for a one-time navigation channel maintenance action (dredging). The litigation was ended in 2005 through a settlement agreement between the plaintiffs and the Corps. In the settlement agreement the Corps was allowed to perform a one-time dredging of the federal navigation channel and related port berthing areas in the winter of 2005/2006. The Corps also agreed to “…initiate and complete a NEPA analysis on a long-term plan for the management of sediment in the lower Snake River, to be designated the Programmatic Sediment Management Plan….” The PSMP is designed to evaluate future actions for sediment management to meet existing authorized project purposes. This Final EIS presents the NEPA analysis of the long-term plan (PSMP) for sediment management directed by the settlement agreement and the current immediate need action (including related regulatory reviews) consistent with the PSMP.

Purpose of and Need for the Proposed Action

The purpose of the proposed action is to maintain the existing projects (the LSRP) by managing sediment that interferes with the existing authorized project purposes by adopting and implementing a PSMP, which includes actions for long-term and immediate needs. The purpose also includes re-establishing the federal navigation channel to the congressionally-authorized dimensions of 14 feet deep by 250 feet wide to address sediment accumulation that is currently interfering with commercial navigation. Coinciding with the current immediate need action is a related need to restore depths necessary to support commercial navigation at non-federal berthing areas of local ports.

The PSMP will provide a programmatic framework to evaluate and implement sediment management measures to address the accumulation of sediment that interferes with existing authorized project purposes. The PSMP is needed to maintain the LSRP by managing, and preventing if possible, sediment accumulation in areas of the lower Snake River reservoirs that interfere with the following existing authorized project purposes:

Commercial navigation by reducing the depth of the federal navigation channel to less than the congressionally-authorized dimensions (14 feet deep by 250 feet wide) when operating at minimum operating pool (MOP), thereby impairing access to port berthing areas, access to navigation locks, and safe movement of tugs and multi-barge tows;

Recreation by limiting water depth at recreation areas to less than original design dimensions and thereby impairing access;

Fish and wildlife conservation by sediment accumulation interfering with irrigation water intakes at Habitat Management Units (HMUs), juvenile ESA-listed fish barge access to loading facilities, and fish barge passage through the reservoirs and locks within the LSRP;

August 2014 xi

Flow conveyance at Lewiston2 by reducing the capacity of the river channel between levees to pass high flows. Sediment management at the confluence of the Snake and Clearwater Rivers may be needed in the long-term to manage the risk of flooding consistent with applicable Corps policies.

Historically within the LSRP, the Corps has approached project maintenance by identifying areas where sediment interfered with authorized project purposes and then taking action to remove the sediment, usually by dredging. The PSMP identifies and evaluates a wide range of measures to accomplish the purpose of maintaining the LSRP and provides a decision-making process to manage and, if possible, prevent sediment accumulation that interferes with authorized project purposes, including addressing the current immediate need action to re-establish the federal navigation channel to congressionally-authorized dimensions of 14 feet deep by 250 feet wide at MOP. Future actions under the PSMP may require project-specific environmental reviews tiered off of this programmatic EIS, and may involve additional studies and authorities.

The Corps has identified a current immediate need action to address sediment accumulation that is interfering with commercial navigation. Sediment accumulation has reduced the congressionally-authorized federal navigation channel depth by several feet (at MOP) at two locations across much of its width:

The downstream navigation lock approach at Ice Harbor Dam

The confluence of the Snake and Clearwater rivers at the upstream end of Lower Granite Reservoir

A current immediate need action is necessary to reestablish the federal navigation channel to its congressionally-authorized dimensions at these locations.

Coinciding with the current immediate need action for reestablishing the congressionally-authorized dimensions of the federal navigation channel is a related need for a maintenance action at the non-federal berthing areas for the ports of Lewiston and Clarkston to restore depths necessary to support commercial navigation. Both ports are located at the upstream end of Lower Granite Reservoir at the confluence of the Snake and Clearwater rivers and are adjacent to the federal navigation channel. The Port of Lewiston is on the right bank of the Clearwater River while the Port of Clarkston is on the left bank of the Snake River. The Ports are responsible for CWA Section 404 and Rivers and Harbors Act Section 10 compliance for their maintenance actions and must apply to the Corps for the necessary regulatory permits (Sections 404/10) to perform this maintenance. As stated above, the EIS also includes the evaluation of potential environmental effects associated with the permit applications for related berthing area maintenance at the ports of Lewiston and Clarkston. The berthing area maintenance is related to the Corps’ purpose of re-establishing the congressionally-authorized dimensions of the federal

2 Although flood risk management is not an authorized project purpose of the LSRP, ensuring adequate flow conveyance through the Lewiston levee system supports the original Lower Granite Project design and all associated project purposes.

xii August 2014 navigation channel and would coincide with federal navigation channel maintenance, pending the outcome of any necessary permit evaluations for the ports’ maintenance actions.

The sediment deposition is also currently interfering with the Corps’ ability to operate the Lower Granite reservoir within one foot of MOP from April through August for ESA listed threatened and endangered juvenile salmon passage. This operation is called for in the NOAA 2014 Supplemental Biological Opinion for the Federal Columbia River Power System (NOAA FCRPS BiOp3) Reasonable and Prudent Alternative (RPA) Action 5.

In addition, the Corps has developed this PSMP EIS to fulfill the relevant portion of the 2005 settlement agreement referenced above.

A Programmatic Approach

A federal agency may enact a programmatic approach versus a project-specific approach for a broad program of management activities under their authority (40 CFR 1502.4(b)). The purpose of programmatic management is to provide consistency in and a roadmap for future project-specific decision-making. The associated programmatic management plan developed by a federal agency requires preparation of a programmatic EIS. This PSMP programmatic EIS includes alternatives that define broad programs for managing sediments through implementation of future actions as they relate to maintaining the authorized project purposes of the LSRP. Actions taken to address the current immediate need action (consistent with the PSMP) to reestablish the navigation channel, including regulatory review by the Corps of related port actions, are covered in this EIS at a site-specific level. Future actions would require project-specific environmental reviews, including preparation of appropriate NEPA documents tiered off of this programmatic

EIS.

The Corps and other agencies conducted extensive analysis of sediment loads and transport to support decision making on the management of sediment deposition that interferes with authorized purposes of the LSRP. This research and analysis represents the most comprehensive assessment of sediment sources, loading, transport, and deposition conducted for the Snake River system. It provides information to support decision making about long-term strategies for managing sediment deposition that interferes with authorized purposes of the lower Snake River.

Alternatives

Past sediment management efforts by the Corps have focused largely on site-specific actions within the reservoirs, particularly dredging, to remove sediment deposits that interfere with authorized purposes of the reservoirs. Through the PSMP EIS, the Corps identified dominant sediment sources within the watershed and evaluated the potential for reducing sediment input from upland sources rather than focusing solely on sediment management within the lower Snake River reservoirs.