Volume I: Table of Contents Table of Contents
Ill Syllabus
ix
Chapter 1. The Feasibility Study 1-3
WRDA 1986, Section 712 1-3
WRDA 1990, Section 116c 1-3
Corps of Engineers Study Activity 1-3
Study Purpose And Scope 1-4
Study Participation And Coordination 1-4
Federal Agencies 1-5
State Agencies 1-5
Local Agencies 1-5
Prior Corps Studies, Reports, and Existing Projects 1-5
Chapter 2.The Study Area 2-1
Bathymetry 2-1
Topography 2-1
Landslide Description 2-1
Geomorphology 2-3
Geology 2-3
Landslides 2-4
Location of the Slide Plane and Seaward Toe of the Slide 2-7
Corps of Engineers Analysis of Slide Plane Toe 2-15
Continuing Monitoring of Landslide Movement 2-15
Landslide Stabilization Plans 2-15
Coastal Processes And Shoreline Conditions 2-17
111 Climate 2-17
Storms 2-17
Tides 2-18
Water Levels 2-18
Currents 2-19
Wave Exposure 2-21
Local Seas and Swells 2-21
Extreme Waves 2-21
Deep Water Extreme Wave Frequency 2-24
Nearshore Extreme Wave Frequency 2-24
Littoral Cells 2-24
Control Volume 2-25
Sediment Sources 2-27
Beachfill 2-27
Landslides 2-27
Stream Contribution 2-27
Bluff Erosion 2-28
Historic Volume Change Within Control Volume 2-28
Sediment Sinks 2-29
Man-Made Structures 2-29
Seismicity 2-35
Sediment Characteristics 2-35
Offshore 2-37
Sediment Chemical Contamination 2-37
Offshore Contamination 2-37
Nearshore Contamination 2-42
Economic and Social Conditions 2-44
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Major Land Uses 2-44
Demographics 2-45
Recreation 2-46
Environmental Conditions 2-46
Air Quality 2-47
South Coast Air Basin Emissions 2-50
Water Quality 2-50
Coastal Zone Biological Resources 2-52
Coastal Vegetation 2-52
Coastal Wildlife 2-52
Marine Biological Resources 2-52
Marine Vegetation 2-54
Marine Invertebrate Animals 2-54
Marine Fishes 2-56
Threatened and Endangered Species 2-57
Aesthetics 2-61
Cultural Resources 2-62
Ethnography 2-62
Prehistory 2-62
History 2-63
Archeological Sites 2-63
Historic Sites 2-64
Chapter 3. Problems, Needs and Opportunities 3-1
Landslide Movement 3-1
Landslide Stabilization Measures Effects 3-1
Future Landslide Movement 3-3
Bluff Erosion and Sediment Production 3-3
Sediment Deposition and Turbidity 3-8 •'
Evaluation of Without-project Habitat Values 3-8
Habitat Evaluation Method Used 3-14
Characteristics of locations Within the Study Area 3-14
Portuguese Bend 3-14
Bunkers Point 3-14
Bunkers Point-Whites Point 3-14
Point Fermin 3-15
Abalone Cove 3-15
Palos Verdes Point 3-15
Habitat Values 3-15
Without-Project Habitat Evaluation 3-16
Chapter 4. Plan Formulation 4-1
Plan Formulation and Decision-Making Process 4-1
Decision-Making Criteria 4-2
Outputs 4-2
Cost Effectiveness and Incremental Cost Analyses 4-2
Significance 4-2
Acceptability 4-2
Completeness 4-3
Effectiveness 4-3
Partnership context . . . . . . . . . . . . 4-3
Reasonableness of Costs 4-3
Systems of Accounts 4-3
National Economic Development 4-3
ii
, Environmental Quality 4-3
• Regional Economic Development 4-3
Other Social Effects 4-3
Risk and Uncertainty 4-3
National Economic Development(NED) Plan 4-4
National Ecosystem Restoration (NER) Plan 4-4
Locally-Preferred Plan 4-4
Planning Objectives and Constraints 4-4
Planning Constraints 4-6
Design Considerations 4-6
Causes of Degradation 4-6
Measures that Could Impact the Landslide 4-7
Measures Impacted by the Landslide 4-8
Initial Screening of Management Measures 4-8
Alternative Plans Considered 4-9
Basis for Design 4-9
Functional Design- Erosion Control 4-10
Functional Design- Natural Sediment Deposit Removal 4-10
Bedrock Uncovering Rates 4-10
Functional Design- Dredging Sediment Removal 4-11
Functional Design-Turbidity Reduction 4-11
Structural Design 4-11
Construction Requirements 4-12
Maintenance Requirements 4-12
Descriptions of Alternative Plans 4-14
No-Action Alternative 4-14
Alternative 1 —Dike 200 Feet Offshore 4-14
S Construction 4-14
Maintenance 4-15
Alternative 2—Containment Dike-400 Feet Offshore 4-18
Construction 4-18
Maintenance 4-18
Alternative 3—Containment Dike 50 Feet Offshore 4-21
Construction 4-21
Maintenance 4-21
Monitoring and Adaptation 4-21
Alternative Plan Costs 4-24
First Cost 4-24
Real Estate Requirements 4-24
Average Annual Costs 4-25
Environmental Effects of Alternative Plans 4-25
Reduced Turbidity 4-26
Other Environmental Effects 4-30
Uncovering Contaminated Sediments 4-30
Contaminated Sediment Offshore 4-30
Water Quality Within the Dike 4-31
Economic Analysis of Restoration Alternatives 4-32
Selection of the NER Plan 4-32
Evaluation of Alternative Plans 4-32
System of Accounts 4-32
National Economic Development 4-33
Environmental Quality 4-35
Regional Development 4-38
IllOther Social Effects 4-38
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Associated Evaluation Criteria 4-40
Outputs 4-40
Cost Effectiveness 4-40
Significance 4-40
Acceptability 4-41
Completeness 4-41
Effectiveness 4-41
Efficiency 4-41
Partnership Context 4-42
Reasonableness of Cost 4-42
Tradeoff Analysis 4-43
Action Versus No-Action 4-43
Tradeoffs between Action Alternatives 4-43
Selection of the Recommended Plan 4-43
Risk and Uncertainty 4-44
Sensitivity Analysis 4-44
Chapter 5. The Recommended Plan 5-1
Plan Description 5-1
Plan Design 5-1
Structural Cross Section Design 5-1
Breakwater Materials 5-3
Breakwater Construction 5-3
OMRR&R 5-4
Real Estate 5-5
Structure Requirements 5-5
Construction Easement 5-5
Environmental Requirements and Commitments 5-5
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Environmental Impact Statement/Report 5-5
Environmental Impacts of Recommended Plan 5-5
Marine Ecology 5-5
Essential Fish Habitat 5-6
Coastal Zone Biology 5-6
Endangered and Threatened Species 5-7
Recreation 5-7
Water Quality 5-7
Cultural and Historic Resources 5-7
Air Quality 5-7
Hazardous and Toxic Wastes 5-8
Aesthetics 5-8
Sediment Chemical Contamination 5-8
Downcoast Shore Impacts 5-9
Other Impacts 5-9
Summary of Environmental Commitments 5-9
Compliance with Federal Laws and Policies 5-10
Fish&Wildlife Coordination Act 5-10
Magnuson-Stevens Fishery Management and Conservation Act 5-10
Endangered Species Act 5-11
Clean Air Act 5-11
Clean Water Act 5-11
National Historic Preservation Act of 1966 5-12
Coastal Zone Management Act 5-12
Executive Order 12898 5-13
Recommended Plan Costs 5-13
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First Cost 5-13
• Cost Estimate Method 5-13
Cost Estimate 5-13
LERRD 5-14
Contingencies 5-14
Fully Funded Project Cost Estimate 5-14
Average Annual Cost 5-14
OMRR&R Costs 5-15
Maintenance of Dike 5-15
Maintenance Removal of Material Behind the Dike 5-15
Recommended Plan Benefits 5-15
Marine Biological Benefits 5-17
Rate of Uncovering Rocky Habitat 5-17
Improved Ecological System 5-18
With-Project Habitat Values 5-20
Economic/Environmental Analysis 5-25
Comparison with Artificial Reef Estimated Cost 5-26
Boulder Fields 5-27
Chapter 6. Plan Implementation 6-1
Recommended Plan Cost-Sharing 6-1
Division of Plan Responsibilities 6-2
Federal Responsibilities 6-2
Non-Federal Responsibilities 6-2
Sponsorship Agreement 6-4
Financial Analysis 6-4
Local Cooperation 6-4
• Procedures for Project Implementation 6-4
Project Management Plan 6-6
Chapter 7. Public and Agency Coordination 7-1
Public Workshops and Meetings 7-1
Agency Coordination 7-1
Review of Draft Report And Draft EIS/EIR 7-5
Chapter 8. Conclusions 8-1
Chapter 9. District Engineer's Recommendation 9-1
List of Figures
Figure S-1. Recommended Plan xii
Figure 2-1. Rancho Palos Verdes Feasibility Study Area 1-4
Figure 2-2. Offshore Bathymetry 2-2
Figure 2-3. Study Area Physical Characteristics 2-2
Figure 2-4. Bedrock Geology 2-4
Figure 2-5. Landslide Delineations 2-5
Figure 2-6. Subslides of the Portuguese Bend Landslide 2-6
Figure 2-7. Monitoring Stations 2-8
Figure 2-8. GPS Stations 2-13
Figure 2-9. Potential Slide Plane and Toe Locations 2-16
0 Figure 2-10. General Circulation-Southern California Bight 2-20
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Figure 2-11. Wave Windows 2-22
Figure 2-12. Control Volume 2-26
Figure 2-13. lsopachs: 1933-1976 Surveys 2-30
Figure 2-14. lsopachs: 1976-1995 Surveys 2-31
Figure 2-15. Sediment Sources and Sinks 2-34
Figure 2-16. Earthquake Faults 2-36
Figure 2-17. Sand Grain Size Distribution on the Palos Verdes Shelf 2-38
Figure 2-18. Silt Grain Size Distribution on the Palos Verdes Shelf 2-39
Figure 2-19. Clay Grain Size Distribution on the Palos Verdes Shelf 2-40
Figure 2-20. Sediment Thickness Contours 2-41
Figure 2-21. Area of Highly-Contaminated Sediment 2-43
Figure 2-22. South Coast Air Basin and Monitoring Stations 2-48
Figure 2-23. Location of Biological Surveys- 1995-1996 2-53
Figure 3-1. Sediment Plume 3-2
Figure 3-2. Shoreline Evolution-Portuguese Bend 3-4
Figure 3-3. Portuguese Bend- 1956 and 1996 3-5
Figure 3-4. Cumulative Landslide Material Loss- Portuguese Bend Landslide 3-6
Figure 3-5. Average Yearly Loss of Material-Portuguese Bend Landslide 3-7
Figure 3-6. Landslide Sediment Dispersion 3-9
Figure 3-7. Grab Sample Locations 3-10
Figure 3-8. Sediment Thickness over Areas of Potential Restoration 3-11
Figure 3-9. Changes in Distribution of Kelp Beds-1928-1980 3-13
Figure 4-1. Sediment Thickness 4-13
Figure 4-2. Alternative 1 -Dike 200 Feet Offshore 4-16
Figure 4-3. Alternative 1 Cross-Section 4-17
Figure 4-4. Alternative 2-Containment Dike-400 Feet Offshore 4-19
Figure 4-5. Alternative 2 Cross-Section 4-20 •
Figure 4-6. Alternative 3-Containment Dike-50 Feet Offshore 4-22
Figure 4-7. Alternative 3 Cross-Sections 4-23
Figure 5-1. Recommended Plan 4-45
Figure 5-2. Recommended Plan Cross-Section Design . 5-2
Figure 5-3. Ecosystem System Benefit Areas 5-16
Figure 5-4. Areas of Potential Restoration 5-19
Figure 5-5. Habitat Restoration Boulder Field 5-27
List of Tables
Table S-1. Economic Costs and Environmental Benefits- Recommended Plan xiii
Table 2-1a. Rates of Landslide Movement at Portuguese Bend 2-9
Table 2-1b. Rates of Landslide Movement at Portuguese Bend 2-11
Table 2-1c. Rates of Landslide Movement at Portuguese Bend 2-12
Table 2-2. 1996 Beach Point Landslide Movement 2-14
Table 2-3. 1997 Beach Point Landslide Movement 2-14
Table 2-4. Tidal Characteristics- Los Angeles Outer Harbor 2-18
Table 2-5. Extreme Wave Conditions 2-23
Table 2-6. Return Period for Unsheltered Deep Water Waves 2-24
Table 2-7. Nearshore Extreme Wave Distribution 2-25
Table 2-8. Stream Yields 2-28
Table 2-9. Rancho Bluff Erosion Estimates 2-28
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• Table 2-10. Control Volume Change 2-29
Table 2-11. Longshore Energy Flux 2-33
Table 2-12. Sediment Budget 2-35
Table 2-13. Maximum Pollution Concentrations in the San Pedro Bay Area- 1991-1993 2-49
Table 2-14. 1993 Base Year Average Annual Day Emission Inventory 2-50
Table 2-15. Surface Water Quality Measurements 2-51
Table 2-16. Subsurface Water Quality Measurements 2-51
Table 2-17 Federal Listed or Proposed Threatened, Endangered Species 2-58
Table 2-18 Shipwrecks 2-64
Table 3-1. Calculation of Habitat Values by Location 3-16
Table 3-2. Without-Project Average Annual Habitat Units Portuguese Bend Area
-Areas 1, 2 and 3 3-17
Table 3-3. Without-Project Average Annual Habitat Units Bunker Point Area-Area 4 3-17
Table 3-4. Without-Project Average Annual Habitat Units Bunker Point-Whites Point Area
-Area 5 3-18
Table 3-5. Study Area Without-Project Habitat Values 3-18
Table 4-1. Initial Screening of Management Measures 4-9
Table 4-2. Rate of Uncovering Rock Substrate 4-11
Table 4-3. First Costs of the Environmental Restoration Alternatives 4-24
Table 4-4. Average Annual Costs of Alternative Plans 4-25
Table 4-5. Habitat Values in the Study Area- Alternative 1 4-27
Table 4-6. Habitat Values in the Study Area-Alternative la 4-28
Table 4-7. Habitat Values in the Study Area-Alternative 2 4-28
Table 4-8. Habitat Values in the Study Area-Alternative 2a 4-29
Table 4-9. Net Gain in Habitat Units With-Project Verses Without-Project 4-29
• Table 4-10. Total Cost per Average Habitat Unit for Feasible Alternatives 4-32
Table 4-11. System of Accounts-National Economic Development Account 4-34
Table 4-12. System of Accounts-Environmental Quality Account 4-36
Table 4-13. System of Accounts-Regional Economic Development and
Other Social Effects Accounts 4-39
Table 5-1. Stone Sizes-Recommended Plan 5-3
Table 5-2. Environmental Commitments 5-10
Table 5-3. Recommended Plan Cost Estimate and Environmental Benefits 5-13
Table 5-4. Estimated Time Required to Expose Rocky Habitat 5-18
Table 5-5. Average Annual Habitat Areas With the Recommended Plan- Area 1
-Portuguese Bend Area Behind the Dike 5-20
Table 5-6. Average Annual Habitat Areas With the Recommended Plan -Area 2
-Portuguese Bend Area from-10 Feet MLLW to-20 feet MLLW 5-21
Table 5-7. Average Annual Habitat Areas With the Recommended Plan-Area 2
- Portuguese Bend Area from-20 Feet MLLW to-30 feet MLLW 5-21
Table 5-8. Average Annual Habitat Areas With the Recommended Plan-Area 3 5-22
Table 5-9. Average Annual Habitat Areas With the Recommended Plan-Area 4
-Bunker Point Area 5-22
Table 5-10. Average Annual Habitat Areas with the Recommended Plan-Area 2
-Bunker Point-Whites Point from-10 feet MLLW to-20 feet MLLW 5-23
Table 5-11. Average Annual Habitat Areas with the Recommended Plan-Area 2
-Bunker Point-Whites Point from-20 feet MLLW to-30 feet MLLW 5-23
Table 5-12. Average Annual Habitat Areas With the Recommended Plan-Area 5
-Existing Kelp Bed in the Bunker Point-Whites Point Area 5-24
Table 5-13. Habitat Values in the Study Area Expected to Be Achieved
• Under Recommended Plan 5-24
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Table 5-14. Net Gain in Habitat Units With-Project Versus Without-Project 5-25 it, 1.
Table 5-15. Recommended Plan Cost Estimate and Environmental Benefits 5-26
Table 6-1. Apportionment of Recommended Plan First Costs 6-1
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