On sandy coasts with moderate to strong wave exposure, infilling associated with littoral drift may impose navigational problems as well as considerable dredging costs. Such problems may be reduced through proper alignment of the access channel and careful design of the coastal structure.

In tidal inlets, estuaries and lagoons, harbours and navigation channels are frequently subject to heavy sedimentation of fine material. In such cases, required maintenance dredging can amount to millions of tonnes per year. This poses serious problems to harbour authorities as the dredged material may be contaminated and can only be deposited under strict regulations after a thorough Environmental Impact Assessment.

DHI has undertaken numerous sedimentation studies in marine and estuarine environments for Port Authorities with the objective of minimising the maintenance dredging and optimising the maintenance dredging schedule.

DHI makes overall optimisations of hydraulic port designs, considering the minimisation of sedimentation, the coastal impact and wave disturbance as well as securing the optimal navigation conditions.

DHI has gained extensive experience on dredging and reclamation projects from consultancy services all over the world. A broad spectrum of environmental impacts from dredging and spoils handling operations with respect to both short-term and long-term effects has been addressed. The short-term effects are most often related to the impacts of sediment spill from dredging operations on the aquatic environment in terms of flora and fauna. The long-term impacts cover the aspects of changes in circulation pattern, coastal zone dynamics and coast morphology from modified coastline and/or sea bed to possible long-term impacts on the aquatic environment.

Assessments and optimal solutions to these problems are established on the basis of DHI's vast experience in the use of advanced modelling tools.