Consolidated clay, if the water content is low, can be used for engineering purposes.Gravel and sand are perhaps the most valuable resource and are routinely used for beach nourishment, wetland restoration and coastal protection.Depending on size and quantity, rock can be a valuable construction material. Rock may range from soft marl like sandstone and coral to hard rock like granite and basalt.This may require treatment of the sediments, but generally speaking, dredged material such as rock, gravel and sand, consolidated clay, silt or soft clay and a mixture of rock, can to varying degrees be used as a resource. In some countries, like Japan, more than 90 percent of dredged material is ultimately put to good use. Not all dredged material is suitable as a resource, but more often the old adage ‘seek and ye shall find’ applies. For instance, if a harbour is dredged, and a nearby beach needs replenishment, then the newly retrieved sediment may be suitable for beach nourishment and coastal protection. Finding a win-win destinationĬontractors and clients now focus on finding uses for dredged material and for coordinating the supply of dredged material with a concurrent demand. Since 90 percent of dredged material is clean, use options can usually be found if all parties think about this during the planning of the project.

When a use purpose is not an option, disposal alternatives must be considered and their destination on land or at sea may become controversial. When dredged material has a purpose, it can be used, for instance, for environmental improvements, giving the material added value and creating a win-win situation.

Over the last few decades, however, research and experience have shown that dredged material can be reused and is not inevitably a waste to be disposed. The destination of this dredged material is often one of the greatest challenges facing a dredging project. Worldwide millions of cubic metres of material are removed each year from ports, harbours and waterways in order to optimise navigation, remediation and flood management.

Define dredged material