MARINA MUD DISPOSAL IN A SHALLOW FETCH-LIMITED ENVIRONMENT

摘要

Pine Harbour Marina has been constructed in a fetch-limited environment within a surrounding catchment that supplies abundant silts to the shallow marine environment. It acts as a natural sediment trap for silts and clays, which require dredging for the marina to operate. Dredging of muds from the navigation approach channel has permitted these non-polluted silts to be returned to the adjacent shallow environment from whence they came. For silts deposited within the marina basin it is proposed to re-agitate them to create a muddy plume, and allow the natural ebb-tidal currents to transport the suspended muds back to the wider embayment. One issue is that the marina basin sediments are mildly contaminated with Cu, but it is shown that dilution during the re-agitation operation will obviate any effects from dispersion of the Cu into the wider embayment.