HANA RAMP – IMPROVEMENTS TO ROCK REVETMENT AND BOAT RAMP LOADING DOCK, MAUI FINAL ENVIRONMENTAL ASSESSMENT and FINDING OF NO SIGNIFICANT IMPACT (FONSI) May 2008 Prepared for: State of Hawaii, Department of Land and Natural Resources: Division of Boating and Ocean Recreation Prepared by: Sea Engineering, Inc. & Shigemura, Lau, Sakanashi, Higuchi and Associates, Inc. SEI Job No: 6-30 TABLE OF CONTENTS PROJECT SUMMARY FINDING OF NO SIGNIFICANT IMPACT (FONSI) 1.0 INTRODUCTION AND SUMMARY.................................................................................. 1 1.1 SUMMARY DESCRIPTION OF THE PROPOSED ACTION............................................................. 1 1.1.1 Repair of the Existing Breakwater.................................................................................1 1.1.2 ADA Compatible Loading Dock ...................................................................................3 1.1.3 Boat Ramp Repair..........................................................................................................3 1.1.4 Boat Wash-Down Area..................................................................................................4 1.1.5 Miscellaneous Minor Improvements .............................................................................4 1.2 SUMMARY DESCRIPTION OF ALTERNATIVES TO THE PROPOSED ACTION .............................. 4 1.2.1 Alternatives to Breakwater Repair.................................................................................4 1.2.2 Alternatives to ADA Accessible Loading Dock............................................................5 1.2.3 Alternatives to Boat Ramp Repairs................................................................................5 1.2.4 Alternatives to Boat Washdown Area............................................................................5 1.2.5 Alternatives to Miscellaneous Minor Improvements.....................................................6 1.3 SUMMARY OF ENVIRONMENTAL CONSEQUENCES AND MITIGATION MEASURES................... 6 1.3.1 Environmental Consequences to the Natural Environment...........................................6 1.3.2 Environmental Consequences to the Human Environment ...........................................8 1.3.3 Mitigation.......................................................................................................................8 2.0 PURPOSE AND NEED FOR THE PROPOSED ACTION .............................................. 9 2.1 PURPOSE OF THE PROPOSED ACTION ..................................................................................... 9 2.2 NEED FOR THE PROPOSED ACTION ........................................................................................ 9 3.0 DESCRIPTION OF THE PROPOSED ACTION............................................................ 12 3.1 PROJECT LOCATION............................................................................................................. 12 3.2.1 Shoreline and Nearshore Characteristics .....................................................................14 3.2.2 Shoreline Erosion.........................................................................................................15 3.2.3 Shoreline Certification.................................................................................................15 3.3 PROJECT FEATURES............................................................................................................. 15 3.3.1 Introduction..................................................................................................................15 3.3.2 Breakwater Repair Plan ...............................................................................................16 3.3.3 Boat Ramp Improvements, Including ADA Ramp and Dock .....................................19 3.3.4 Washdown Area...........................................................................................................21 3.3.5 Miscellaneous Minor Improvements ...........................................................................22 3.4 CONSTRUCTION OPERATIONS.............................................................................................. 22 3.5 MATERIAL QUANTITIES....................................................................................................... 23 3.6 ESTIMATED CONSTRUCTION COST ...................................................................................... 24 4.0 ALTERNATIVES INCLUDING THE PROPOSED ACTION ...................................... 25 4.1 DESCRIPTION OF THE PROPOSED ACTION ............................................................................ 25 4.2 ALTERNATIVES TO BREAKWATER REPAIR........................................................................... 25 4.3 ALTERNATIVES TO ADA ACCESSIBLE LOADING DOCK....................................................... 26 Sea Engineering, Inc. i Hana Boat Ramp Environmental Assessment TABLE OF CONTENTS Hana, Maui 4.4 ALTERNATIVES TO BOAT RAMP REPAIRS............................................................................ 26 4.5 ALTERNATIVES TO BOAT WASHDOWN AREA...................................................................... 26 5.0 NATURAL ENVIRONMENTAL SETTING ................................................................... 27 5.1 GENERAL PHYSICAL ENVIRONMENT ................................................................................... 27 5.1.1 Bathymetry and Nearshore Bottom Conditions...........................................................27 5.1.2 Shoreline Conditions....................................................................................................28 5.1.3 Wind.............................................................................................................................28 5.1.4 Waves...........................................................................................................................29 5.1.5 Water Levels ................................................................................................................31 5.2 MARINE WATER QUALITY .................................................................................................. 31 5.3 BIOLOGICAL RESOURCES ..................................................................................................... 35 5.3.1 Marine Biological Resources.......................................................................................35 5.3.2 Terrestrial Biological Resources (Flora).....................................................................39 6.0 HUMAN ENVIRONMENTAL SETTING........................................................................ 41 6.1 INTRODUCTION.................................................................................................................... 41 6.2 RECREATIONAL USE............................................................................................................ 41 6.3 RESERVATIONS AND/OR CONSERVATION ZONES................................................................ 41 6.4 EXISTING INFRASTRUCTURE................................................................................................ 42 6.5 HISTORIC AND CULTURAL RESOURCES ............................................................................... 42 6.6 AIR AND NOISE QUALITY .................................................................................................... 42 7.0 ENVIRONMENTAL CONSEQUENCES OF THE PROPOSED ACTION ................. 43 7.1 THE NATURAL ENVIRONMENT ............................................................................................ 43 7.1.1 The Natural Physical Environment..............................................................................43 7.1.2 Water Quality...............................................................................................................43 7.1.3 Marine and Terrestrial Biology....................................................................................44 7.1.4 Threatened and Endangered Species ...........................................................................45 7.2 THE HUMAN ENVIRONMENT ............................................................................................... 45 7.2.1 Recreational Use ..........................................................................................................45 7.2.2 Reservations or Conservations Areas ..........................................................................46 7.2.3 Existing Infrastructure .................................................................................................46 7.2.4 Historic and Cultural Resources ..................................................................................46 7.2.5 Air and Noise Quality ..................................................................................................46 8.0 MITIGATION...................................................................................................................... 47 8.1 LONG TERM MITIGATION .................................................................................................... 47 8.2 MITIGATION DURING CONSTRUCTION................................................................................. 47 8.2.1 Protection of Endangered Species ...............................................................................47 8.2.2 Best Management Practices .........................................................................................47 8.3 PROJECT MONITORING .......................................................................................................