Download - How Can You Manage Floods
How can you manage floods?
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……
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
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.
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.
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.
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
Soft Management
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.
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
Afforestation
• This is re-planting trees in the catchment
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.