ENVIRONMENTAL ASSESSMENT for the

COMPREHENSIVE MANAGEMENT PLAN

TIJUANA SLOUGH NATIONAL WILDLIFE REFUGE

SAN DIEGO COUNTY, CALIFORNIA

March 1999

Prepared by:

U.S. Fish and Wildlife Service

San Diego National Wildlife Refuge Complex

2736 Loker Avenue West, Suite A

Carlsbad, California 92008

760/930-0168

Table of Contents

Chapter 1. PURPOSE OF AND NEED FOR ACTION

1.1 Proposed Action

1.2 Purpose of and Need for the Proposed Action

1.3 Project Area

1.4 Decisions to be Made

1.5 Issues Identified and Selected for Analysis

1.6 Issues Not Selected for Detailed Analysis

1.7 Other Related Agency Actions

1.8 National Wildlife Refuge System and Authorities

1.8.1 Mission of the U.S. Fish and Wildlife Service and National Wildlife Refuge System

1.8.2 Purpose of the Tijuana Slough National Wildlife Refuge

1.8.3 Goals of the Tijuana Slough National Wildlife Refuge

1.8.4 Determining Compatible Uses of the Tijuana Slough National Wildlife Refuge

1.8.5 Refuge Operating Needs System (RONS)

Chapter 2. ALTERNATIVES, INCLUDING THE PREFERRED ALTERNATIVE

2.1 Alternative A: Implement Refuge Comprehensive Management Plan to Provide Increased Levels of Wildlife Management and Visitor Services (Preferred Alternative)

2.2 Alternative B: Implement Refuge Comprehensive Management Plan to Provide Existing Levels of Wildlife Management and Visitor Services (No Action Alternative)

2.3 Actions Common to All Alternatives

2.3.1 Emergency Dredging of the Mouths of the Oneonta Slough and Tijuana River

2.3.2 Annual Sand Dune Maintenance

2.3.3 Predator Management for the Recovery of Endangered and Threatened Species

2.3.4 Acquisition of Additional Lands Along Sea Coast Drive

2.3.5 Construction of New Office and Classroom Space by the California Department of Parks and Recreation on Lands Under Easement to the State of California

2.3.6 Relocation of Damaged Trails in the Tijuana River Floodplain

2.4 Comparison of Management Actions Between Alternative A and Alternative B

Chapter 3. AFFECTED ENVIRONMENT

3.1 Physical Environment

3.2 Biological Environment

3.3 Social and Economic Environment

3.4 Archaeological and Historical Resources

Chapter 4. ENVIRONMENTAL CONSEQUENCES

4.1 Environmental Consequences of Implementing Alternative A (Preferred Alternative). Implement Refuge Comprehensive Management Plan to Provide Increased Levels of Wildlife Management and Visitor Services

4.1.1 Effects on the Physical Environment from Increased Wildlife Management Programs

4.1.2 Effects on the Biological Environment from Increased Wildlife Management Programs

4.1.3 Effects on the Social and Economic Environment from Increased Wildlife Management Programs

4.1.4 Effects on Archaeological and Historical Resources from Increased Wildlife Management Programs

4.1.5 Effects on the Physical Environment from Increased Visitor Services

4.1.6 Effects on the Biological Environment from Increased Visitor Services

4.1.7 Effects on the Social and Economic Environment from Increased Visitor Services

4.1.8 Effects on Archaeological and Historical Resources from Increased Visitor Services

4.1.9 Effects on the Physical Environment from Increased Control of Invasive Weeds

4.1.10 Effects on the Biological Environment from Increased Control of Invasive Weeds

4.1.11 Effects on the Social and Economic Environment from Increased Control of Invasive Weeds

4.1.12 Effects on Archaeological and Historical Resources from Increased Control of Invasive Weeds

4.2 Environmental Consequences of Implementing Alternative B (No Action Alternative). Implement Refuge Comprehensive Management Plan to ProvideExisting Levels of Wildlife Management and Visitor Services

4.2.1 Effects on the Physical Environment from Existing Wildlife Management Programs

4.2.2 Effects on the Biological Environment from Existing Wildlife Management Programs

4.2.3 Effects on the Social and Economic Environment from Existing Wildlife Management Programs

4.2.4 Effects on Archaeological and Historical Resources from Existing Wildlife Management Programs

4.2.5 Effects on the Physical Environment from Existing Visitor Services

4.2.6 Effects on the Biological Environment from Existing Visitor Services

4.2.7 Effects on the Social and Economic Environment from Existing Visitor Services

4.2.8 Effects on Archaeological and Historical Resources from Existing Visitor Services

4.2.9 Effects on the Physical Environment from Existing Efforts to Control Invasive Weeds

4.2.10 Effects on the Biological Environment from Existing Efforts to Control Invasive Weeds

4.2.11 Effects on the Social and Economic Environment from Existing Efforts to Control Invasive Weeds 4-8

4.2.12 Effects on Archaeological and Historical Resources from Existing Efforts to Control Invasive Weeds

4.3 Environmental Consequences Common to All Alternatives From Emergency Dredging, Sand Dune Maintenance, Predator Management, Acquisition of Additional Lands, Construction of New Facilities, and Relocation of Damaged Trails

4.3.1 Effects on the Physical Environment from Emergency Dredging

4.3.2 Effects on the Biological Environment from Emergency Dredging

4.3.3 Effects on the Social and Economic Environment from Emergency Dredging

4.3.4 Effects on Archaeological and Historical Resources from Emergency Dredging

4.3.5 Effects on the Physical Environment from Annual Sand Dune Maintenance

4.3.6 Effects on the Biological Environment from Annual Sand Dune Maintenance

4.3.7 Effects on the Physical Environment from Increased Predator Management

4.3.8 Effects on the Biological Environment from Increased Predator Management

4.3.9 Effects on the Social and Economic Environment from Increased Predator Management

4.3.10 Effects on the Archaeological and Historical Resources from Increased Predator Management

4.3.11 Effects on the Physical Environment from the Acquisition of Additional Lands Along Sea Coast Drive

4.3.12 Effects on the Biological Environment from the Acquisition of Additional Lands Along Sea Coast Drive

4.3.13 Effects on the Social and Economic Environment from the Acquisition of Additional Lands Along Sea Coast Drive 4-13

4.3.14 Effects on the Archaeological and Historical Resources from Acquisition of Additional Lands Along Sea Coast Drive

4.3.15 Construction of New Office and Classroom Space by the CaliforniaDepartment of Parks and Recreation on Lands Under Easement to the State of California

4.3.16 Effects on the Physical Environment from Construction of New Office and Classroom Space by the California Department of Parks and Recreation on Easement Lands

4.3.17 Effects on the Biological Environment from Construction of New Office and Classroom Space by the California Department of Parks and Recreation on Easement Lands

4.3.18 Effects on the Social and Economic Environment from the Construction of New Office and Classroom Space by the California Department of Parks and Recreation on Easement Lands

4.3.19 Effects on the Archaeological and Historical Resources from the Construction of New Office and Classroom Space by the California Department of Parks and Recreation on Easement Lands

4.3.20 Effects on the Physical Environment from the Relocation of Damaged Trails in the Tijuana River Floodplain

4.3.21 Effects on the Biological Environment from the Relocation of Damaged Equestrian Trails in the Tijuana River Floodplain

4.3.22 Effects on the Social and Economic Environment from the Relocation of Damaged Equestrian Trails in the Tijuana River Floodplain

4.3.23 Effects on the Archaeological and Historical Resources from the Relocation of Damaged Equestrian Trails in the Tijuana River Floodplain

4.4 Unavoidable Adverse Impacts and Irreversible and Irretrievable Commitments of Resources

4.5 Short-term Uses Versus long-term Productivity

4.6 Cumulative Impacts

Chapter 5. COORDINATION, CONSULTATION, AND COMPLIANCE

5.1 Agency Coordination and Public Involvement

5.2 Environmental Review and Coordination

5.2.1 National Environmental Policy Act

5.2.2 Other Federal Laws, Regulations, and Executive Orders

5.2.3 Distribution and Availability

Chapter 6. LIST OF PREPARERS AND REVIEWERS

References Cited

Figures

Figure 1. Project Location Map

Tables

Table 2-1. Comparison of Management Actions Between Alternative A and Alternative B

Appendices

Appendix A. Distribution List for Environmental Assessment

Appendix B. Biological Monitoring and Recovery Actions at the Tijuana Slough National Wildlife Refuge