Formation of Levees

• What is happening at 1?

  Before a flood, water is held in the channel in low flow conditions.

  This can raise the river bed, reducing channel capacity

  
• What is happening at 2?


  During a flood, water passes over the surface and the heaviest materials is deposited first, close to the banks.

  This deposition is due to friction with the land causing reduced velocity

  
• What is happening at 3?


  After many flood, these deposits will build levees and cause them to get higher.

  These are made up of coarse sediment on the inside and finer sediment on the outside