Therefore, the presence of flood defences are not taken into account.  Flood Zones are used to raise flood awareness with our customers, flood risk management partners and for strategic spatial and development planning purposes.

Flood Zone definitions

Flood Zone 3:

  • the extent of a flood from rivers with a 1% (1 in 100) chance or greater of happening in any given year
  • the extent of a flood from the sea with a 0.5% (1 in 200) chance or greater of happening in any given year

Flood Zone 2:

  • the extent of a flood from rivers or from the sea with up to a 0.1% (1 in 1000) chance of happening in any given year
  • contains areas recorded to have flooded in the past
  • Flood Zone 2 is important from a planning context as it forms the basis of Zone C in the Welsh Government Development Advice Map (DAM)

Find out more about how we manage flood risk

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