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N.C. 12 Ocracoke Island "Hot Spot" Feasibility Study

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N.C. 12 Ocracoke Island Feasibility Study: NC 12 Ocracoke Island Hot Spot Ocracoke Island, Hyde County Prepared for: North Carolina Department of Transportation, Project Development and Environmental Analysis Prepared by: WSP | Parsons Brinckerhoff Raleigh, NC December 2016 Table of Contents 1.0 EXECUTIVE SUMMARY ............................................................................................ 1-1 2.0 INTRODUCTION ........................................................................................................ 2-1 2.1 Project History ..................................................................................................... 2-1 2.2 Funding ................................................................................................................. 2-1 2.3 Problem Statement and Purpose of Study...................................................... 2-2 2.4 Project Limits ....................................................................................................... 2-2 3.0 COASTAL CONDITIONS ......................................................................................... 3-1 3.1 Shoreline and Erosion Studies ......................................................................... 3-1 3.1.1 Definition of Vulnerability and Methods for Evaluation .................. 3-1 3.1.2 Setback ...................................................................................................... 3-2 3.1.3 Background Erosion Rates ..................................................................... 3-3 3.1.4 Baseline Conditions................................................................................. 3-8 3.2 Dredging Operations – Potential Sand Resources ...................................... 3-11 3.3 Nearshore/Offshore Sediment Sources ......................................................... 3-12 3.4 Consideration of Geotextiles .......................................................................... 3-12 4.0 DESIGN CONSIDERATIONS AND CRITERIA ................................................... 4-1 4.1 Design Criteria ..................................................................................................... 4-1 4.2 Traffic Estimate .................................................................................................... 4-3 5.0 ENVIRONMENTAL SETTING ................................................................................. 5-1 5.1 Human Environment .......................................................................................... 5-1 5.1.1 Socio-economics ...................................................................................... 5-1 5.1.2 Land Use ................................................................................................... 5-1 5.1.3 Cultural Resources .................................................................................. 5-2 5.1.4 Bicycle and Pedestrian Facilities ........................................................... 5-2 5.1.5 Section 4(f) Resources ............................................................................. 5-3 5.1.6 Visual Character ...................................................................................... 5-4 5.2 Natural Environment .......................................................................................... 5-4 5.2.1 Significant Natural Heritage Area ........................................................ 5-4 5.2.2 Terrestrial Communities ........................................................................ 5-4 5.2.3 Terrestrial Wildlife .................................................................................. 5-6 5.2.4 Aquatic Communities ............................................................................. 5-6 5.2.5 Protected Species ..................................................................................... 5-6 5.2.6 Wetlands ................................................................................................... 5-8 i 5.2.7 Essential Fish Habitat ............................................................................. 5-8 6.0 DESCRIPTION OF ALTERNATIVES ...................................................................... 6-1 6.1 Short-Term (5-Year) Alternatives ..................................................................... 6-2 6.1.1 5-Year Option 1 – Large Scale Beach Nourishment ............................ 6-2 6.1.2 5-Year Option 2 – Dune Nourishment ................................................. 6-3 6.1.3 5-Year Option 3 – Roadway Relocation and Dune Nourishment .... 6-3 6.1.4 5-Year Option 4 – Bridge over Hot Spot .............................................. 6-3 6.2 Long-Term (50-Year) Alternatives .................................................................... 6-9 6.2.1 50-Year Option 1 – Pamlico Sound Bridge .......................................... 6-9 6.2.2 50-Year Option 2 – Bridge Alternative throughout Hot Spot ........... 6-9 6.2.3 50-Year Option 3 – Relocate Roadway and Bridging ....................... 6-10 6.2.4 50-Year Option 4 – Bridge in Existing Easement .............................. 6-10 6.2.5 50-Year Option 5 – Large Scale Beach Nourishment ........................ 6-11 6.2.6 50-Year Option 6 – Ferry Service to Expanded Terminal in Ocracoke Village 6-11 6.2.7 50-Year Option 7 – Ferry Service to New Ferry Terminal North of Ocracoke Village ................................................................................................. 6-12 7.0 COMPARISON OF ALTERNATIVES ..................................................................... 7-1 7.1 Nourishment Options: 5-Year Option 1, 5-Year Option 2, 50-Year Option 5 7-1 7.1.1 Human Environment Impacts ............................................................... 7-1 7.1.2 Natural Environment Impacts ............................................................... 7-2 7.1.3 Constructability ....................................................................................... 7-2 7.1.4 Cost ............................................................................................................ 7-3 7.2 Road and Bridge Options: 5-Year Option 4, 50-Year Options 1-4 .............. 7-3 7.2.1 Human Environment Impacts ............................................................... 7-3 7.2.2 Natural Environment Impacts ............................................................... 7-5 7.2.3 Constructability ....................................................................................... 7-6 7.2.4 Cost ............................................................................................................ 7-7 7.3 Ferry Options: 50-Year Options 6 and 7 .......................................................... 7-8 7.3.1 Human Environment Impacts ............................................................... 7-8 7.3.2 Natural Environment Impacts ............................................................... 7-9 7.3.3 Constructability ....................................................................................... 7-9 7.3.4 Cost .......................................................................................................... 7-10 7.4 Combination Option: 5-Year Option 3 .......................................................... 7-10 7.4.1 Human Environment Impacts ............................................................. 7-10 7.4.2 Natural Environment Impacts ............................................................. 7-11 7.4.3 Constructability ..................................................................................... 7-11 7.4.4 Cost .......................................................................................................... 7-11 7.5 Summary ............................................................................................................. 7-12 7.5.1 Beach Nourishment Options ............................................................... 7-12 ii 7.5.2 Road and Bridge Options ..................................................................... 7-12 7.5.3 Ferry Options ......................................................................................... 7-13 8.0 SUMMARY OF AGENCY COORDINATION ....................................................... 8-1 8.1 Merger Team Meetings ...................................................................................... 8-1 8.2 Individual Agency Coordination Meetings ................................................... 8-2 9.0 NEXT STEPS.................................................................................................................. 9-1 10.0 WORKS CITED .......................................................................................................... 10-1 11.0 APPENDIX ................................................................................................................... 11-1 Traffic Analysis 2014 Shoreline and Erosion Update 2010 Vulnerability Analysis Update List of Figures Figure 1. Storm Damaged Section of NC 12 ......................................................................... 2-2 Figure 2. Project Study Area ................................................................................................... 2-3 Figure 3. Project Area with Projected Shorelines ................................................................. 3-4 Figure 4. 5-Year Option 1 – Large Scale Beach Nourishment ............................................ 6-5 Figure 5. 5-Year Option 2 – Dune Nourishment .................................................................. 6-6 Figure 6. 5-Year Option
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