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i. Model Grid Development The model grid will extend from approximately 1 mile south of Sebastian Inlet to the southern boundary of the County (R-119). Sebastian Inlet has been excluded from this modeling effort due to the effort that would be required to include inlet effects. The model would have to be expanded to include Indian River Lagoon and significantly impact model setup and run time. The south County line has been selected as the southern boundary of the model because no alternatives are expected to be evaluated in this area. The beach at the south end of County (Sector 8) is stable to accretional based on previous analyses, thus not requiring intervention. The updated shoreline and volumetric change analysis will determine the validity of this assumption before finalizing the model domain. Given the computational intensity required to model sediment transport within the entire model domain, nested grids will be created for three areas in which beach management strategies can be further investigated. Three individual SWAN grids will be nested within the countywide SWAN grid to evaluate wave transformation adjacent to coastal structures. Similarly, three DeIft3D-FLOW grids will be used with domain decomposition in order to provide high level of detail of flows and morphology evolution in the three project areas and maintain efficient simulation timescales. It is anticipated that these finer grids will be focused in Sectors 3, 5, and 7, where erosion is a chronic problem and fill and/or structural solutions may be required. Sector 3 has historically suffered higher erosion rates though a beach and dune restoration project was recently constructed and a repair to the project is in the permitting process. Sector 1A has also experienced higher volumetric losses and shoreline retreat. However, this erosional stress is recognized as being a function of the Sebastian Inlet and is being addressed by the Sebastian Inlet District. No detailed evaluation is proposed in this area. The bathymetric data sets will be utilized to depict the past and present bathymetry using the model grids. Similarly, hardbottom surreys will be incorporated within the nested DeIft3D-FLOW grids. Historic hardbottom will be imported through GIS maps provided by the County. The model will be populated with available data. Nearshore bathymetric and topographic data will rely upon the latest countywide survey. Offshore hardbottom will be modeled by including all available data from.previous County monitoring efforts to the 2013 hardbottom mapping effort in Sector 3. Offshore bathymetric data will be based on surveys conducted by NOAA or USGS. Wind, wave, and water level measurements will be based on data collected by FIT, USACE and NOAA. No field work (hydrographic surveying, wave and tide Gauge deployment) is proposed in support of the modeling effort. If it is determined that the available data is insufficient to develop an accurate model then collection of additional data will be discussed with the County. The current assessment is that the available data should be sufficient. ii. Water Level& Current Calibration The water level and current measurements collected will be utilized to calibrate the Delft3DFLOW model. Wave measurements and water levels previously collected will provide the offshore boundary conditions for each calibration run. Water levels will provide the basis for evaluating the results of each calibration run. Present bathymetries will be used as input, along with concurrent wind data from NOAA. DeIft3DFLOW and SWAN will be run simultaneously to resolve the influence of waves on the 33