1. How can you manage floods?

2. There is no perfect way to protect floods. The traditional choices are….
To build flood defences
To straighten and deepen the river and cut off meanders
To make storage areas for extra water
These are all called hard management.
The types of hard management are……

3. Dams These trap and store water, and let it out in a controlled way.
They can generate electricity.
Upstream of the dam the land floods to make a reservoir.
They are expensive but very effective
Makes a massive change to the ecosystem

4. Embankments These are raised banks along the river.
They effectively make the river deeper so it can hold more water before it floods.
They are expensive and don’t look natural.
They do protect the land around them.

5. Flood walls
These are built around settlements and important factories or roads.
They are quite expensive and don’t look very natural.
They are pretty effective.

6. Straightening and deepening the river
This is called channelising the river.
It makes the water move through the river faster.
So it doesn’t build up and is less likely to flood.
Changes the ecosystem in the river and spoils the natural look.
Further downstream, where the river is not channelised the water builds up and floods.

7. Storage areas
The water can be pumped out of the river and stored in temporary lakes.
Then it is pumped back in after the water in the river has gone down a bit.
Effective, but you need to have a large bit of spare land that isn’t used, so that you can flood it!
Area of land

8. Soft Management

9. Washlands These are parts of the floodplain that are allowed to flood.
They can’t be built on.
They are usually used for sports pitches or nature reserves.
Area of land at Swanage set aside to flood if needed.

10. Land-use zoning
This is where land has different building controls depending on how far away from the river it is.
Land next to the river isn’t allowed to be used for building, the next land can be but only for low-risk housing.
The last zone is for high-risk buildings like hospitals, old peoples homes and dangerous factories

11. Afforestation
This is re-planting trees in the catchment

12. Warning Systems
Warnings are issued by the Environmental Agency (in the UK) so that local people can put sandbags by their homes, take furniture upstairs or evacuate the area.