Management of Flooding Case Studies
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Extreme weather event: summer of 2007
This was the wettest summer on record since records began in 1766.
During June, July and August a succession of depressions tracked across the UK, bringing heavy rain and
triggering multiple flood events.
Intense heavy rainfall is not unusual in the summer (convectional rainfall), but in 2007 the frequency and
spatial extent was unprecedented.
More than 387mm (15.2ins) of rain fell in England and Wales in the three months to 23 July - more than
double the average of 186mm (7.3ins) for the period.
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Shrewsbury
In response to floods in 2000 the Environment Agency spent £6 million and improved on the existing flood defences
in the following ways:
1. As Shrewsbury has such a historic heritage and aesthetic considerations are paramount, the Agency adopted
a creative and innovative approach.
2. Shrewsbury is the first urban area in the UK to have the K System. The temporary and demountable barrier,
made of steel and aluminium does not need any foundations so it can be put up anywhere so it is more
effective and flexible
3. There are also embankments and stone walls in place which can also be made higher using the temporary
defences.
4. Shrewsbury also uses inflatable dams
5. There is also control of the riverside land use in which inappropriate building have been stopped and some
areas of the town have been allowed to flood
6. There is also flood risk analysis, flood risk monitoring and warnings by the environment agency
7. Shrewsbury was not really affected by the floods in the summer of 2007 therefore it can summarised that
the flood management was successful
Tewksbury
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Tewkesbury in Gloucestershire often experiences flooding because it is built on a flood plain.
Meadows surrounding two are regularly flooded by River Severn, which adds nutrients to the soil
Tewkesbury is situated where the Avon meets the Severn, and where a number of other tributaries
converge.
Event
 Heavy rain on 20 July caused extensive flooding across the lower Severn catchment
 Many places river levels were the highest ever recorded.
 Across Tewkesbury, around 80-90mm of rain recorded on 20 July, equivalent to almost two month’s rain in
just one day.
 The river reached a height of 5.3m when normally it is 0.5m high.
 Properties were first flooded on 20 July from surface water that could not drain away quickly enough or
from watercourses, which reacted quickly to the local run-off (including some main rivers such as the River
Swilgate).
 Further flooding occurred over the weekend from main rivers, including the River Severn, Carrant Brook and
River Avon.
 Some properties flooded twice, first from surface water then from rising river levels.
 The centre of Tewkesbury town was completely cut off from vehicles as a result of the floods.
 Overall, five people died and 1,831 properties were inundated, hundreds of families spent months huddled
in caravans on driveways in front of their properties, protecting what little they have left from burglars while
waiting for overworked builders to start work.
Management
 The July flood on the River Severn between Upton and Gloucester has been assessed as having between a
0.66 per cent and 0.5 per cent probability of occurring in any year.
 Tewksbury has no flood defences like those in Bewdley or in Shrewsbury.
 The town has not flooded for a few years so it was not protected.
 However, there have been new housing developments and many believe that this has reduced the lag time
and caused the floods.
 Tewksbury serves as an example of how poor management can have disastrous consequences in an extreme
weather event.