Dredging is the removal of sediments and debris from the bottom of lakes, rivers, harbors, and other water bodies. It is a routine necessity in waterways around the world because sedimentation—the natural process of sand and silt washing downstream—gradually fills channels and harbors.

How are rivers dredged?

When dredging, the operator lowers the boom of a dredge to the bottom (or side) of the body of water. A rotating cutter-bar then uses teeth to loosen the settled material, as the submersible pump removes the sediment from the bottom of the waterway. The silt and debris are then transported away for final processing.

Why are rivers dredged?

Dredging involves using machinery to excavate sediment from a river bed in order to improve and re-shape the river. Rivers often silt up if this material is left to gather, impeding the flow of water. Dredging of navigable waterways is useful for boat traffic. It can also be used for land reclamation projects.