Levees

• A levee is a build up of alluvium on the river banks of a river. Levees are caused by floods
• In times of low flow, material is deposited onto the river bed, raising its height.
• In times of flood, water leaves the channel and spreads out over the flood plain. As it does so, it looses its energy and deposits it’s load.
• The heavier material is deposited onto the river banks and the finer material is carried further onto the flood plain
• After many floods, the river builds a bank on either side. Artificial levees can also be used to protect the surrounding land from flooding
• Examples of levees: lower courses of the rivers Moy and Liffey
• Formation of a levee: