Tidal Pond Network Analysis on Cape Cod

A model has been developed and successfully applied to analyze a network of tidal ponds connected by culverts and bridges. Measured tidal fluctuations under normal and spring tide conditions at the seaward terminus of the tidal ponds were applied as boundary conditions. The model uses the secant modification of the Newton-Raphson method for solving a set of nonlinear differential equations. It was necessary to develop special conduit file generation and interpolation techniques to render the model feasible in terms of required computational time. The model adequately represented tidal fluctuations measured in the tidal ponds under existing conditions. The model was then applied to predict changes in tidal fluctuations resulting from replacement of one of the culverts with alternative bridge designs with and without freshwater runoff. The predictions enabled separate assessment of impacts on shore-side properties with individual septic systems and on water quality, flora, and fauna within the tidal ponds.