As part of the Boston Harbor cleanup program, Woods Hole Group was contracted to develop shore protection plans for Deer Island where the central sewage treatment plant and outfall tunnel are being constructed.  As part of this large project, Woods Hole Group conducted numerical and physical model analyses of wave climatology, storm water levels, and wave run-up so that an effective and cost efficient shore protection plan could be developed for the island.

High-resolution bathymetry was obtained in support of the physical and numerical modeling efforts.  The detailed bathymetry was crucial in resolving the interaction of the nearshore waves and the offshore bathymetry.  The accurate bathymetry also was an important component for the value engineering and structure optimization design components of the study.  The offshore wave climatology was evaluated using the numerical model WAVAD.  Historical wind data from 30 extratropical storms and 5 hurricanes were used with the wave model to hindcast wave conditions at the site.  Results from the WAVAD model were used as input to the nearshore spectral wave model, STDR, to evaluate wave refraction and diffraction caused by variations in nearshore bottom topography.  Wave characteristics (wave height, period, and direction) at the shoreline were predicted by the nearshore wave model for each of the storm conditions modeled.  Areas of the project site subject to increased wave energy were identified for further analyses.  The numerical tidal model, CURZ3, also was utilized to determine storm surge elevations resulting from passage of the extratropical and tropical storms.  Results from the numerical modeling of waves and tidal surge were used in an extremal analysis to predict nearshore wave heights and water levels for 5-, 10-, 25-, 50-, and 100-year storm events.  Wave run-up and scour modeling was conducted using the extreme wave and water level data generated by the models.  Results from these model runs were used to optimize seawall design specifications.  Finally, two-dimensional physical modeling of the seawall design was performed using a test facility to evaluate the proposed structural design.