Environmental Assessment for Rehabilitation of the Levee System in the Title: Tijuana River Flood Control Project Version: DRAFT Date: December 2016 Prepared for: International Boundary and Water Commission 4171 N Mesa St., Suite C310 El Paso, TX 79902 Prepared by: 848 W. Hadley Ave. Las Cruces, NM 88005 Contract Number: IBM09D0008 Task Order Number: IBM10T0048 Environmental Assessment for Rehabilitation of the Levee System in the Tijuana River Flood Control Project Draft TABLE OF CONTENTS Section Page EXECUTIVE SUMMARY .................................................................................................................. ES-1 1.0 INTRODUCTION....................................................................................................................... 1-1 1.1 Purpose and Need for Action ........................................................................................... 1-1 1.2 Background ...................................................................................................................... 1-1 1.2.1 USIBWC Authority ............................................................................................ 1-1 1.2.2 Flood Control Project Description ...................................................................... 1-3 1.2.2.1 History and Development ................................................................... 1-3 1.2.2.2 Description of the Levees in the Tijuana River FCP .......................... 1-5 1.3 Consultations and Public Involvement ............................................................................ 1-5 1.3.1 Agency Consultation........................................................................................... 1-5 1.3.2 Public Involvement ............................................................................................. 1-6 1.3.2.1 Scoping ............................................................................................... 1-6 1.3.2.2 Draft EA Review ................................................................................ 1-6 2.0 DESCRIPTION OF PROPOSED ACTION AND ALTERNATIVES .................................. 2-1 2.1 Proposed Action ............................................................................................................... 2-1 2.1.1 North Levee Enlargement ................................................................................... 2-1 2.1.2 North Levee Embankment Protection ................................................................. 2-2 2.1.3 Rodent Burrow Repair and Mitigation ............................................................... 2-2 2.1.4 Removal of Sediment and Debris ....................................................................... 2-5 2.2 No Action Alternative ...................................................................................................... 2-5 3.0 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ................ 3-1 3.1 Water Resources .............................................................................................................. 3-2 3.1.1 Affected Environment ......................................................................................... 3-2 3.1.1.1 Flood Control ..................................................................................... 3-2 3.1.1.2 Hydrology ........................................................................................... 3-3 3.1.1.3 Groundwater Resources ..................................................................... 3-3 3.1.1.4 Water Quality ..................................................................................... 3-5 3.1.2 Environmental Consequences ............................................................................. 3-6 3.1.2.1 Proposed Action ................................................................................. 3-6 3.1.2.2 No Action Alternative ........................................................................ 3-7 3.2 Biological Resources ....................................................................................................... 3-7 3.2.1 Affected Environment ......................................................................................... 3-7 3.2.1.1 Vegetation .......................................................................................... 3-7 3.2.1.2 Wildlife ............................................................................................... 3-8 3.2.1.3 Threatened and Endangered Species .................................................. 3-9 3.2.1.4 Aquatic Ecosystems ......................................................................... 3-15 3.2.1.5 Unique or Sensitive Areas ................................................................ 3-15 3.2.1.6 Wetlands ........................................................................................... 3-15 3.2.2 Environmental Consequences ........................................................................... 3-16 3.2.2.1 Proposed Action ............................................................................... 3-16 i Environmental Assessment for Rehabilitation of the Levee System in the Tijuana River Flood Control Project Draft 3.2.2.2 No Action Alternative ...................................................................... 3-18 3.3 Land Use ........................................................................................................................ 3-19 3.3.1 Affected Environment ....................................................................................... 3-19 3.3.1.1 Residential and Commercial............................................................. 3-19 3.3.1.2 Agricultural ...................................................................................... 3-19 3.3.1.3 Recreational and Natural Resource Areas ........................................ 3-21 3.3.1.4 Other Significant Land Uses in the Project Vicinity ........................ 3-21 3.3.1.5 Land Use Planning Documents ........................................................ 3-22 3.3.2 Environmental Consequences ........................................................................... 3-23 3.3.2.1 Proposed Action ............................................................................... 3-23 3.3.2.2 No Action Alternative ...................................................................... 3-23 3.4 Cultural Resources ......................................................................................................... 3-23 3.4.1 Affected Environment ....................................................................................... 3-23 3.4.2 Environmental Consequences ........................................................................... 3-24 3.4.2.1 Proposed Action ............................................................................... 3-24 3.4.2.2 No Action Alternative ...................................................................... 3-25 3.5 Socioeconomic Resources and Transportation .............................................................. 3-25 3.5.1 Affected Environment ....................................................................................... 3-25 3.5.1.1 Regional Economics ......................................................................... 3-25 3.5.1.2 Environmental Justice ...................................................................... 3-27 3.5.1.3 Transportation .................................................................................. 3-28 3.5.2 Environmental Consequences ........................................................................... 3-29 3.5.2.1 Proposed Action ............................................................................... 3-29 3.5.2.2 No Action Alternative ...................................................................... 3-30 3.6 Environmental Health .................................................................................................... 3-30 3.6.1 Affected Environment ....................................................................................... 3-30 3.6.1.1 Air Quality ........................................................................................ 3-30 3.6.1.2 Noise ................................................................................................. 3-31 3.6.1.3 Public Health and Environmental Hazards ....................................... 3-32 3.6.2 Environmental Consequences ........................................................................... 3-34 3.6.2.1 Proposed Action ............................................................................... 3-34 3.6.2.2 No Action Alternative ...................................................................... 3-37 4.0 CUMULATIVE IMPACTS AND IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES ......................................................................................... 4-1 4.1 Cumulative Impacts ......................................................................................................... 4-1 4.1.1 Past, Present, and Reasonably Foreseeable Actions ........................................... 4-1 4.1.2 Cumulative Impacts Summary ............................................................................ 4-1 4.1.2.1 Proposed Action ................................................................................. 4-1 4.1.2.2 No Action Alternative ........................................................................ 4-3 4.2 Irreversible and Irretrievable Commitment of Resources