Modelling the effect of proposed channel deepening on the tides in Port Phillip Bay

The Victorian State Government is investigating a proposal to deepen the channels into Port Phillip Bay in order to bring larger ships into the Bay. The Port of Melbourne Corporation, the Victorian State Government authority responsible for the channel deepening, has concluded that the largest increase in tidal height due to the channel deepening will be eight millimetres. This paper is an independent study on the effect of the channel deepening on the astronomical tides. The levels of tides for the existing topography and for the topography including the proposed channel deepening have been computed. Our results show that the effect of channel deepening on the astronomical tides will be to increase the maximum tidal height at most locations. We calculate that the largest increase will be nine millimetres, confirming the results of the Port of Melbourne Corporation.