WEST BELLE PASS BARRIER HEADLAND RESTORATION CWPPRA PROJECT Fed No. TE-52 ENVIRONMENTAL ASSESSMENT Lafourche Parish, Louisiana U.S. Department of Commerce National Oceanic and Atmospheric Administration National Marine Fisheries Service August 2010 CONTENTS Section Page ACRONYMS ............................................................................................................................................... vi EXECUTIVE SUMMARY .................................................................................................................... ES-1 1.0 INTRODUCTION ........................................................................................................................... 1 1.1 PROJECT LOCATION ..............................................................................................1 1.2 CWPPRA PROJECT SELECTION PROCESS ............................................................3 1.3 ENVIRONMENTAL SETTING ..................................................................................3 1.3.1 Hydrology / Geomorphology ................................................................................. 4 1.3.2 Wetland Loss ......................................................................................................... 4 1.3.3 Restoration ............................................................................................................. 5 1.4 PURPOSE AND NEED ...................................................................................................... 5 1.4.1 Purpose .................................................................................................................. 5 1.4.2 Need for Action ..................................................................................................... 6 2.0 PROPOSED ACTION AND ALTERNATIVES ............................................................................ 7 2.1 ALTERNATIVES CONSIDERED BUT ELIMINATED .................................................. 7 2.2 ALTERNATIVES CONSIDERED IN DETAIL ................................................................ 7 2.2.1 The No Action Alternative .................................................................................. 12 2.2.2 Alternative 1 (Preferred Alternative) ................................................................... 12 2.2.3 Alternative 2 ........................................................................................................ 12 2.2.4 Alternative 3 ........................................................................................................ 13 2.3 OFFSHORE BORROW AREAS ..................................................................................... 13 3.0 AFFECTED ENVIRONMENT ..................................................................................................... 15 3.1 PHYSICAL ENVIRONMENT ......................................................................................... 15 3.1.1 Geology, Soils, and Topography ......................................................................... 15 3.1.2 Climate and Weather ........................................................................................... 16 3.1.3 Air Quality ........................................................................................................... 16 3.1.4 Surface Water Resources ..................................................................................... 17 3.2 BIOLOGICAL ENVIRONMENT .................................................................................... 17 3.2.1 Vegetative Communities ...................................................................................... 17 3.2.2 Aquatic Habitats .................................................................................................. 18 3.2.3 Benthic Habitats ................................................................................................... 19 3.2.4 Essential Fish Habitat and Associated Managed Species .................................... 19 i CONTENTS (Continued) Section Page 3.2.5 Fisheries Resources .............................................................................................. 23 3.2.6 Wildlife Resources ............................................................................................... 24 3.2.7 Threatened and Endangered Species ................................................................... 26 3.3 CULTURAL RESOURCES ............................................................................................. 29 3.3.1 Historic, Prehistoric, and Native American Resources ........................................ 29 3.3.2 Socioeconomics (Income and Environmental Justice) ........................................ 30 3.3.3 Land Use .............................................................................................................. 31 3.3.4 Infrastructure ........................................................................................................ 31 3.3.5 Noise .................................................................................................................... 32 4.0 ENVIRONMENTAL CONSEQUENCES .................................................................................... 33 4.1 IMPACT-PRODUCING FACTORS ................................................................................ 41 4.1.1 Dredge Operating Characteristics ........................................................................ 41 4.1.2 Effluent Discharge at Sea .................................................................................... 41 4.1.3 Total Depths of Cut Expected within the Borrow Areas ..................................... 42 4.1.4 Emplacement of Dredged Material ...................................................................... 42 4.2 PHYSICAL RESOURCES ............................................................................................... 45 4.2.1 Impacts on Geology, Topography, and Physical Oceanographic Processes ........ 45 4.2.2 Impacts on Climate and Weather ......................................................................... 47 4.2.3 Impacts on Air Quality ........................................................................................ 47 4.2.4 Impacts on Water Resources ................................................................................ 48 4.3 BIOLOGICAL ENVIRONMENT .................................................................................. 489 4.3.1 Impacts on Vegetative Communities ................................................................... 49 4.3.2 Impacts on Fisheries and Aquatic Resources ....................................................... 52 4.3.3 Impacts on Essential Fish Habitat ........................................................................ 53 4.3.4 Impacts on Wildlife Resources ............................................................................ 54 4.3.5 Impacts on Marine Mammals .............................................................................. 55 4.3.6 Impacts on Threatened and Endangered Species ................................................. 56 4.4 CULTURAL RESOURCES ............................................................................................. 60 4.4.1 Impacts on Historic, Prehistoric, and Native American Resources ..................... 60 4.4.2 Impacts on Terrestrial Cultural Resources ........................................................... 61 4.4.3 Impacts on Offshore Cultural Resources ............................................................. 60 4.4.4 Impacts on Land Use/Recreation ......................................................................... 60 4.4.5 Impacts on Infrastructure ..................................................................................... 61 4.4.6 Impacts on Socioeconomics ................................................................................. 62 4.4.7 Impacts on Noise ................................................................................................. 63 4.5 OTHER CONSIDERATIONS.......................................................................................... 63 ii CONTENTS (Continued) Section Page 4.5.1 Cumulative Impacts ............................................................................................. 63 4.5.2 Invasive Species ................................................................................................... 67 4.5.3 Coordination ........................................................................................................ 67 4.5.4 Compliance with Laws and Regulations .............................................................. 68 5.0 CONCLUSIONS ........................................................................................................................... 71 6.0 PREPARERS ................................................................................................................................. 72 7.0 DISTRIBUTION LIST .................................................................................................................. 73 8.0 LITERATURE CITED .................................................................................................................. 74 APPENDIX Appendix A COMMENTS ON DRAFT ENVIRONMENTAL ASSESSMENT AND INFORMAL CONSULTATIONS iii CONTENTS (Continued) TABLES Table Page 1 DESIGN FEATURES OF PROJECT ALTERNATIVES ............................................................. 11 2 CHARACTERISTICS OF THE BORROW AREAS ...................................................................