Draft Phase II Restoration Plan #3.2: Mid-Barataria Sediment Diversion Table of Contents Page Table of Contents .............................................................................................................................................. i Figures ................................................................................................................................................................. iii Tables .................................................................................................................................................................... v Acronyms and Abbreviations .................................................................................................................... vi Executive Summary ..................................................................................................................................ES-1 1.0 Introduction ........................................................................................................................................ 1-1 1.1 Background and Summary of the Settlement ............................................................................................ 1-3 1.2 DWH NRDA Trustees, Trustee Council, and Trustee Implementation Groups ........................ 1-4 1.3 Authorities and Regulations ............................................................................................................................... 1-5 1.3.1 OPA Compliance and NRDA Evaluation Criteria ................................................................. 1-5 1.3.2 Compliance with Other Laws ........................................................................................................ 1-6 1.4 Restoration Goals and Objectives ..................................................................................................................... 1-7 1.5 Alternatives Evaluated in this Plan.................................................................................................................. 1-9 1.6 No-Action Alternative .......................................................................................................................................... 1-13 1.7 Coordination with Other Gulf Restoration Programs ......................................................................... 1-14 1.8 Public Participation .............................................................................................................................................. 1-17 1.8.1 Coordination of Public Outreach with EIS ........................................................................... 1-18 1.8.2 Public Comment Process .............................................................................................................. 1-19 1.8.3 Administrative Record ................................................................................................................... 1-19 1.9 Document Organization ..................................................................................................................................... 1-19 2.0 Restoration Planning Process..................................................................................................... 2-1 2.1 Summary of Injuries Addressed in this Draft RP ..................................................................................... 2-1 2.2 Additional Injuries Addressed by Other Plans .......................................................................................... 2-3 2.3 Screening for a Reasonable Range of Alternatives .................................................................................. 2-4 2.3.1 Selection of a Mid-Barataria Basin Sediment Diversion for Further Analysis ..................................................................................................................................................... 2-4 2.3.2 Process for Screening Alternatives for the Proposed MBSD Project ........................ 2-7 2.3.3 Proposed MBSD Project Location Alternatives ................................................................... 2-9 2.3.4 Proposed MBSD Project Operations ....................................................................................... 2-11 2.3.5 Sediment Diversion Outfall Features ..................................................................................... 2-14 2.4 Alternatives Not Considered for Further Evaluation in this Draft RP ........................................ 2-14 2.5 Alternatives Considered for Further Evaluation in this Draft RP ................................................. 2-15 i Draft Phase II Restoration Plan #3.2: Mid-Barataria Sediment Diversion 3.0 OPA Evaluation of the Alternatives .......................................................................................... 3-1 3.1 Summary of OPA NRDA Evaluation Criteria .............................................................................................. 3-1 3.2 OPA Evaluation of the Alternatives ................................................................................................................. 3-1 3.2.1 Alternative 1: Sediment Diversion with a Variable Flow up to a Maximum of 75,000 cfs ................................................................................................................................................ 3-2 3.2.2 Alternatives 2–6 ................................................................................................................................ 3-48 3.2.3 No-Action Alternative .................................................................................................................... 3-71 3.2.4 Overall OPA Evaluation Conclusions ..................................................................................... 3-72 4.0 Compliance with Other Laws and Regulations ................................................................... 4-1 5.0 List of Preparers and Reviewers ............................................................................................... 5-1 6.0 List of Repositories .......................................................................................................................... 6-1 7.0 References ........................................................................................................................................... 7-1 Appendix A: Monitoring and Adaptive Management Plan for the Proposed MBSD Project ...................................................................................................................................... A-1 Appendix B: Mitigation and Stewardship Plan for the Proposed MBSD Project ............ B-1 Appendix C: Matrix of Eliminated Alternatives ............................................................................. C-1 ii Draft Phase II Restoration Plan #3.2: Mid-Barataria Sediment Diversion Figures Page Figure 1-2. Design Features and Construction Footprint of the Proposed MBSD Project and Its Alternatives. ........................................................................................................................................................................ 1-11 Figure 3-1. Alternative 1 Would Create New Deltaic Landforms and Build and Sustain Land (area shown in blue) in the Barataria Basin as Sediment Is Deposited. ................................................. 3-7 Figure 3-2. Percentage of Acres in the Barataria Basin Created by Alternative 1 Would Increase over Time, Even Though Total Land Gained Peaks after 30 Years. .......................................................... 3-8 Figure 3-3. Alternative 1 Would Typically Deliver the Highest Diversion Flows in the Winter and Spring, and Operate under Base Flow Conditions in the Summer and Fall. ............................... 3-9 Figure 3-4. Operation of the Diversion Would Maintain a Seasonal Fluctuation in Salinity Characteristic of Estuaries. ............................................................................................................................................. 3-9 Figure 3-5. Alternative 1 Would Increase the Average NO3 Fraction of TN at Northern/Mid-Basin CRMS Station 3985 and CRMS Station 0276 Nearest the Diversion Compared to the No-Action Alternative .................................................................................................................................................... 3-11 Figure 3-6. Alternative 1 Would Increase the Average PO4 Fraction of TP at Northern/Mid-Basin CRMS Station 3985 and CRMS Station 0276 Nearest the Diversion Compared to the No-Action Alternative .................................................................................................................................................... 3-12 Figure 3-7. While Wetland Habitat Declines under Both Alternatives, More Brackish and Saline Habitat Is Lost over Time, and More Freshwater/Intermediate Habitats Are Retained or Created under Alternative 1 than the No-Action Alternative. .................................................................. 3-13 Figure 3-8. Operation of the Diversion Will Maintain a Diversity of Habitat Types under Alternative 1, Although the Relative Amount of Brackish and Saline Habitats Are Lower under Alternative 1 than the No-Action Alternative by 2070. ................................................................. 3-14 Figure 3-9. Oyster HSIs for Eastern Oysters Decrease in the Barataria Basin under Alternative 1 Compared to the No-Action Alternative due to Increased Freshwater Associated with the Diversion,