Minimising Harbour Siltation: The Economic and Environmental Future of Ports

Following world-wide review, five substantive generic sediment management systems were identified. Auto-flushing is a proven means to remove fines from impounded docks on entry. Entrance Flow Optimisation can significantly reduce fines-trapping in blindending basins. In the 1960s fluid mud was a largely intractable problem. The paper outlines how, first, Passive Nautical Depth determined by continuous-reading point-sampling (1975), followed by towed, undulating gamma-ray densimeters (1986) were developed. The most farreaching refinement, Active Nautical Depth using acoustic definitions of navigability, has evolved since 1990, accompanied by the ability to destroy particular organic contaminants in-situ. Like auto-flushing, it potentially provides a total solution requiring no conventional maintenance dredging. The discipline is moving rapidly to whole estuary rather than, narrowly, to port management, and to creating fluid mud where none previously existed.