Flood management case study - Boscastle, Cornwall
Why were flood defences needed?
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 which does not allow water to pass through it, eg granite.. Boscastle is also located on a The meeting point where one river joins onto another river. of three rivers. These factors led to a flash flood which led to over 1,000 homes, cars and businesses being 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 A type of rock which allows water to pass through its joints and cracks, eg limestone. surface - this allowed cars to be much higher 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.