What is coastal deposition?

Deposition occurs when material being transported is dropped by constructive waves. It happens because waves have less energy.

Deposition happens when the swash is stronger than the backwash and is associated with constructive waves.

So, where does deposition happen? Deposition is likely to occur when:

waves enter an area of shallow water;
waves enter a sheltered area, eg a cove or bay;
there is little wind;
a river or estuary flows into the sea, reducing wave energy;
there is a good supply of material, and the amount of material being transported is greater than the wave energy can transport.

Deposition creates a range of landforms. You can find out more on the depositional landforms page.

Summary

What Is Coastal Deposition?
Coastal deposition is when the sea drops the material it has been transporting, building up new landforms.
Role of Constructive Waves
Constructive waves with strong swash and weak backwash deposit material onto beaches.
Conditions That Encourage Deposition
Deposition is more likely in sheltered bays, calm weather, shallow water, and where wave energy is low.
Swash and Backwash Balance
Deposition happens when swash is stronger than backwash, allowing material to settle on the beach.
Examples of Deposition Sites
Rivers meeting the sea and wide beaches are common areas where deposition occurs.
Impact on Coastal Landscapes
Deposition builds features like beaches, spits, and bars, shaping the coastline over time.