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River management - AQAFlood management case study - Boscastle, Cornwall

Hard engineering management involves using artificial structures, such as dams and embankments. Soft engineering management is a more natural approach to manage flooding, such as floodplain zoning.

Part of GeographyRiver landscapes in the UK

Flood management case study - Boscastle, Cornwall

In August 2004, the village of Boscastle saw a month's worth of rain fall in two hours. The drainage basin of Boscastle is steep and rock. Boscastle is also located on a of three rivers. These factors led to a flash flood which caused over one thousand homes, cars and businesses to be swept away and damaged.

The flood defence scheme

To prevent this type of flood happening again, the environmental agency invested 拢10 million into several flood defences, such as:

  • Widening and deepening the river channel - this allowed the river to carry more water.
  • Removing low bridges and replacing them with wider bridges - this meant large amounts of water could flow freely underneath the bridge and the bridge wouldn't act like a dam (in the 2004 flood, vegetation and debris became blocked, creating the effect of a dam).
  • Raising the car park and using a surface - this allowed cars to be much higher and so they were less likely to be swept away.
  • Tree management - dead trees were removed to prevent them being swept away, causing blockages under bridges. Land owners were encouraged to maintain vegetation and plant new trees.
Boscastle has had several improvements to its flood defences: vegetation has been cleared, the car park has been raised, the river deepened and widened, and the bridge has also been widened.