Processes forming river landscapes - lower course

Levée

Formation of a levée

• The river is on its floodplain with a very low gradient.
• The river is mainly depositing (silt and sand).
• When the river floods a lot of silt is deposited on the river banks and much less on the floodplain.
• Frequent flooding continues this build up.
• When the river is flowing normally it deposits in the river bed.
• This raises the river above the floodplain.
• Usually the built-up levées protect the plain from flooding.