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
Dredging is most commonly used to increase the depth of channels, and anchorages to improve the safety of boats. It also can be used to protect marine life, wildlife, and humans. Over time the sediment can become contaminated with pollution which is commonly known as environmental dredging.