When does deposition happen?

• When a river's velocity decreases, and no longer has the energy to transport its load, it deposits it
• Larger rocks transported by traction are only carried for short distances during periods of high flow, they are deposited in a river's upper course
• Smaller sediment is carried further downsteam mostly in suspension. It is deposited on a river's bed and banks where velocity slows due to friction
• Lots of deposition occurs in the river's mouth where velocity reduces because of the gentle gradient and also by interaction with tides