Sarasota Bay Sarasota County, Florida
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FINAL SECTION 1135 ECOSYSTEM RESTORATION REPORT and ENVIRONMENTAL ASSESSMENT SARASOTA BAY SARASOTA COUNTY, FLORIDA November 2002, Revised March 2003 SARASOTA BAY Sec. 1135 Final ERR/EA Nov. 2002, Revised March 2003 SYLLABUS This report provides the results of a feasibility level study conducted under the authority of Section 1135 of the 1986 Water Resources Development Act (WRDA), as amended, to restore and provide habitat for fisheries and wildlife in Sarasota Bay, Sarasota County, Florida. Section 1135 authorizes the Corps of Engineers to make modifications in the structures and operations of water resources projects constructed by the Corps, if determined that the modifications are: (1) feasible and consistent with the authorized project purposes, and (2) will improve the quality of the environment in the public interest. The primary benefits from projects must be associated with improvements to fish and wildlife resources. During the construction of the Gulf Intracoastal Waterway project in the 1950’s and early 1960’s, some of the material dredged from the channel was placed within Sarasota Bay, within areas of mangroves and shallow water bay bottom, creating upland disposal islands. The locally preferred plan for this Section 1135 project calls for the restoration of three of the six dredged material disposal islands. The recommended plans for the three project disposal islands include excavation and removal of dredged material deposits, removal of exotic vegetation, planting of native plant species, and shoreline stabilization. The ecosystem restoration will result in the creation and protection of a total of nearly 33 acres of habitat, including: 2 acres of uplands; 20.6 acres of low marsh and mangroves; 7.9 acres of tidal lagoon / mud flats; and the protection of 2 acres of mangrove dominated bird nesting habitat. The habitat created will benefit a wide variety of fish and wildlife species, including the federally listed Piping Plover and West Indian Manatee. Indirect benefits would expand throughout the entire Sarasota Bay ecosystem, which due to extensive development, currently has very little or no high quality wetland or upland wildlife habitat. The total project cost is estimated at $6,740,483. Cover Photo: Bird Colony Islands, Sarasota Bay Sarasota Bay Ecosystem Restoration Report Table of Contents Section Page No. 1 Study Authority…………………………………………………………………………… 1 2 Study Purpose and Scope………………………………………………………………. 1 2.1 Location………………………………………………………………………….. 2 3 Prior Studies, Reports, and Existing Water Projects………………………………... 2 4 Plan Formulation……………………..………………………………………………….. 4 4.1 Existing Conditions……………………………………………………………...4 4.2 Future Without-Project Conditions……………………………………………. 7 4.3 Problems and Opportunities…………………………………………………… 8 4.4 Objectives and Constraints…….……………………………………………… 9 4.5 Management Measures…..……………………………………….……………9 4.6 Alternatives………………………………………………………….….………..11 4.7 Comparison of Alternatives……………………………….…………………… 18 4.8 Trade-Off Analysis…………………...…………………………………………. 31 4.9 Risk and Uncertainty……..…………………………………………………….. 31 4.10 Selection of Recommended Plans….………………………………………… 32 5 Description of Selected Plans……..……………………………………………………. 36 5.1 Design and Construction Considerations.…………………………………… 38 5.2 Economic Evaluation and Plan Costs……….……………………………….. 40 5.3 Operation and Maintenance Considerations………………………………… 43 5.4 Cost Effectiveness / Incremental Cost Analysis………….…………………. 43 5.5 Plan Accomplishments…..…………………………………………………….. 44 5.6 Environmental and Social Effects………..…………………………………… 45 5.6.1 Threatened and Endangered Species……...……………………….45 5.6.2 Salt Flats (Salterns)…………………………………………………… 45 5.6.3 Bird Habitat……………………………………………...…………….. 45 5.6.4 Coastal Barrier Resources…………………………………………… 46 5.6.5 Cultural Resources……………………………………………………. 46 5.6.6 Recreational Interests…………………….………………………….. 48 5.6.7 Navigation / Channel Maintenance Dredging……………………... 49 5.6.8 Local Cooperation…………………………………………………….. 50 6 Plan Implementation……………………………………………………..………………. 50 6.1 Division of Plan Responsibilities……………………….………………………50 6.2 Views of Non-Federal Sponsor & Other Agencies …………………………. 54 7 Coordination, Public Views, and Comments………………………………………….. 54 8 Recommendations…………..…………………………………………………………… 54 9 List of Preparers………………………………………………………………………….. 58 Ecosystem Restoration Report List of Tables Table Page No. 1. Management Measures and Planning Objectives………………………..………….. 11 2. Big Edwards Island Evaluation Matrix.……………………………………………….... 21 3. Big Edwards Island Plan Evaluation……………………………………….…. ……….. 22 4. Skiers’ Island Evaluation Matrix………………………………………………………… 23 5. Skiers’ Island Plan Evaluation………………………………………………………….. 24 6. Jim Neville Marine Preserve Evaluation Matrix…..…………………………………... 25 7. Jim Neville Marine Preserve Plan Evaluation…….…………………………...……… 26 8. Palmer Point Park Evaluation Matrix…………………………………………….……..27 9. Palmer Point Park Plan Evaluation……………………………………………………. 28 10. Snake Island Evaluation Matrix...………………………………………………………. 29 11. Snake Island Plan Evaluation………………………………………………………….. 30 12. Estimated Construction Cost…………………………………..……………………….. 41 13. Total Project Costs…………………………………………………………………..…... 42 14. Operation and Maintenance Costs…………………………………………………….. 43 Sarasota Bay Environmental Assessment Table of Contents Section Page No. 1.00 Project Purpose…………………………………………………………………………... EA-1 2.00 Location…………………………………………………………………………………… EA-1 3.00 Alternative Plans…………………………………………………………………….. EA-3 3.01 Big Edwards Island……………………………………………………………... EA-11 3.02 Skiers’ Island……………………………………………………………………. EA-11 3.03 Bird Colony Islands…………………………………………………………….. EA-11 3.04 Jim Neville Marine Preserve…………………………………………………... EA-11 3.05 Palmer Point Park………………………………………………………………. EA-12 3.06 Snake Island…………………………………………………………………….. EA-12 4.00 Description of Affected Environment…………………………………………………… EA-12 4.01 Vegetation……………………………………………………………………….. EA-14 4.02 Threatened and Endangered Species……………………………………….. EA-15 4.03 Fish and Wildlife Resources…………………………………………………… EA-16 4.04 Coastal Barrier Resources…………………………………………………….. EA-16 4.05 Water Quality……………………………………………………………………. EA-17 4.06 Aesthetic Resources…………………………………………………………… EA-19 4.07 Recreation Resources…………………………………………………………. EA-19 4.08 Navigation……………………………………………………………………….. EA-19 4.09 Cultural Resources……………………………………………………………... EA-19 5.00 Probable Impacts of the Recommended Alternative Plans………………………… EA-20 5.01 Vegetation……………………………………………………………………….. EA-22 5.02 Threatened and Endangered Species……………………………………….. EA-27 5.03 Fish and Wildlife Resources…………………………………………………… EA-27 5.04 Coastal Barrier Resources…………………………………………………….. EA-28 5.05 Water Quality……………………………………………………………………. EA-28 5.06 Hydrology………………………………………………………………………... EA-28 5.07 Aesthetic Resources…………………………………………………………… EA-29 5.08 Recreation Resources…………………………………………………………. EA-29 5.09 Cultural Resources……………………………………………………………... EA-30 5.10 Cumulative Impacts…………………………………………………………….. EA-30 6.00 Coordination………………………………………………………………………………. EA-30 6.01 Agency Comments……………………………………………………………... EA-31 7.00 Compliance with Environmental Statutes……………………………………………… EA-33 8.00 Public Involvement……………………………………………………………………….. EA-36 8.01 Public Comments to the Draft EA and ERR…………………………………. EA-37 Sarasota Bay Section 1135 Ecosystem Restoration Report/Environmental Assessment List of Figures Number 1 Project Location Map 2 Big Edwards Alternative 1 3 Big Edwards Alternative 2 4 Big Edwards Alternative 3 5 Big Edwards Alternative 4 6 Skiers’ Island Alternative 1 7 Skiers’ Island Alternative 2 8 Skiers’ Island Alternative 3 9 Skiers’ Island Alternative 4 10 Jim Neville Marine Preserve Alternative 1 11 Jim Neville Marine Preserve Alternative 2 12 Jim Neville Marine Preserve Alternative 3 13 Jim Neville Marine Preserve Alternative 4 14 Jim Neville Marine Preserve Alternative 5 15 Palmer Point Park Alternative 1 16 Palmer Point Park Alternative 2 17 Palmer Point Park Alternative 3 18 Palmer Point Park Alternative 4 19 Snake Island Alternative 1 20 Snake Island Alternative 2 21 Snake Island Alternative 3 22 Snake Island Alternative 4 23 Big Edwards Island Existing Conditions 24 Skiers’ Island Existing Conditions 25 Bird Colony Islands Existing Conditions 26 Jim Neville Marine Preserve Existing Conditions 27 Palmer Point Park Existing Conditions 28 Snake Island Existing Conditions 29 Historical Aerial Big Edwards Island 30 Historical Aerial Skiers’ Island 31 Historical Aerial Bird Colony Islands 32 Historical Aerial Jim Neville Marine Preserve 33 Historical Aerial Palmer Point Park 34 Historical Aerial Snake Island List of Appendices A Section 404(B) Evaluation B Coastal Zone Management Program C Engineering Appendix and Plans and Specifications Work Plan D MCACES Cost Estimates E Geotechnical Report F Real Estate Assessment G Coordination Act Report / Agency Coordination H Cost Effectiveness Analysis and Incremental Cost Analysis I Public Involvement PROJECT MODIFICATION FOR IMPROVEMENT OF THE ENVIRONMENT SARASOTA BAY, SARASOTA COUNTY, FLORIDA ECOSYSTEM RESTORATION REPORT 1. STUDY AUTHORITY This report was prepared under the authority of Section 1135 of the 1986 Water Resources Development Act (WRDA), as amended. The act reads, in part, as follows: “The Secretary is authorized to carry out a program for the purpose of making such modifications in the structures and operations of water resources projects constructed by the Secretary which the Secretary determines (1) are feasible and consistent