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O • O Scope of Work Page 15 Task 3.1 Analysis Of Combined Beach Fill and Structural Implementation For Sector 7 Shoreline Following discussion with Department officials at a meeting in Tallahassee on August 29, 2000, ATM will conduct a conceptual design and layout of groin field and/or nearshore breakwaters to determine the optimization of sand placement in the South County (Sector 7) project area. The USACE Coastal Engineering Manual, coastal engineering design principles, and site-specific feature understanding (topography and nearshore bathymetry) will be utilized to complete this design and layout. The wave refraction/diffraction model REF/DIF will be utilized to simulate the pre- and post- installation wave field modifications of the project shoreline, both with and without structures. This wave condition establishment will be utilized in conjunction with the GENEralized Model for Simulating Shoreline Change (GENESIS), to simulate wave - induced longshore sand transport and evolution of the shoreline. This simulation will be utilized to demonstrate the effectiveness of the coastal protection structures in modifying (reducing) beach fill placement quantities on the shoreline. Wave data will be assembled from a combination of the Wave Information Study (WIS) hindcast data and real-time wave gauging apparatus in the area. Florida Institute of Technology and Sebastian Inlet Tax Distdct wave data will additionally be acquired and reviewed to determine adequacy for use in addition to, or in lieu of, the WIS data. A gdd will be established sufficient to fully simulate the bathymetry and shoreline adjacent to and contiguous with the Sector 7 project area. Model simulations will be conducted on sufficient wave 'cases' to adequately demonstrate the wave propagation over and shoreward of the proposed structures/beach fill section to the shoreline. The gdd will encompass the entire project area and depths seaward a sufficient distance to generate the incoming wave fronts, and a distance of up to 1 -mile north and south (alongshore) of the proposed project boundaries. Gdd coverage with these dimensions should be sufficient to depict pre- and post -construction impacts to the near field, project shoreline, and project -adjacent shorelines. A report will be prepared detailing the methodology, set-up and results of the simulation. Task 3.2 Alternatives Evaluation for Sector 7 Corrective Actions The alternatives to be developed and further analyzed for Sector 7 are: • no action (resulting in further construction of revetments and seawalls), • beach fill with periodic nourishment (-63 cy/ft), • beach fill design altematives (-20% and 35%, respectively, reduction in fill volumes and their corresponding hardbottom impact reductions), • a tapered groin field of 10-12 structures in combination with beach fill, • modified taper in the central portion of the project, utilizing a lesser number of groin structures with beach fill, and • a third altemative design configuration utilizing structures and beach fill. An analysis of fill redistribution (i.e., performance over time) will be conducted utilizing predictive modeling techniques. Modeling using REF/DIF and GENESIS, as described in Task 3.1 above, will be performed. A meeting will be conducted with the Project G'.\WNDOWS\TEMMIRC Secmn 1 2 7 AdW-.W Serv-01A800d-J1QM1