  Sediment is fine particles carried in a liquid... such as sand in a river.   It gets carried along when the river is flowing swiftly, but if the water slwos down enou … gh, such as in a lake, or at a dam, the sediment stops moving as swiftly as it had been and settles to the bottom of the waterway.ediments in geology are solid fragments of inorganic or organic material that come from the weathering of rock or biological processes and are carried and deposited by wind, … water, or ice.