Dredging is the process of excavating or removing sediments from the bottom of lakes, rivers, estuaries, or marine (ocean) locations. Sediment excavation or dredging is conducted for multiple purposes. These purposes include navigation, mineral extraction (mining), construction activities (e.g., laying underwater pipeline), and the environmental cleanup of polluted sediments.

Dredging is generally conducted by floating construction equipment and is accomplished by mechanical, hydraulic, or hydrodynamic (agitation) processes. Mechanical dredges generally employ drag lines, open or closed clam shell buckets, or an endless chain of buckets to excavate the sediment and place it in a container such as a barge or scow. The dredged sediment is then transported in the barge or scow for beneficial use at a location on land or in the water (e.g., construction material, fill or habitat enhancement), to a nearby disposal site, or in some cases, to an aquatic disposal site at...