Stirring up sediments is a process that involves agitating the bottom of a body of water, such as a lake or river, in order to cause the sediment to become suspended in the water. The term 'stir up sediments' is often used in reference to the process of roiling, which is the act of stirring up the sediment in order to create a disturbance in the water. Roiling is typically done with a boat or other device that is designed to create a disturbance in the water, and it can be used to help clear out debris or to help improve water quality.