1. Presented by: Stephen Scott How has the UK flood management programme changed over the years? What does the future hold?

2. Contents  Introduction  UK flood management  Case Study – Thames Barrier  The Future – likely impact of global warming  Conclusions

3. Introduction LocationEstimated Financial CostEstimated Human Loss Madeira (Portugal)N/A42 dead, 100 injured Pakistan$1 - $2 billion2000 dead, 2500 injured China$13 billion3200+ dead, 1,000+ missing Queensland (Australia)$10 - $25 billion30-40 dead BrazilUnknown51+ dead - Recent major flooding events worldwide -Discharge of River Thames 100 times smaller than Indus river - Estimated that 1.5 million people live on floodplain - £80 billion infrastructure at risk (RGS, 2010) - Flooding in the UK a major concern for those responsible for the management of rivers and coastal defences

4. Causes of UK Flooding Heavy rainfall or thunderstorms over short period of time Tewekesbury – 2007 Boscastle -2004 Urbanisation Deforestation Cultivation Tidal Surges – most likely form of flooding in the UK Kent & Yorkshire - 2007

5. UK Flood management Flood management evolves as a result of social and economic conditions Bear the Loss – Do Nothing Modify Damage Susceptibility – Land Use Planning Modify the Flood – Flood Protection Modify the Loss Burden – Disaster Relief

6. Land Use Planning Flood alleviation technique - reducing impact of flooding Manages flooding risk to development in the flood plain Flood map of River Avon running through Bristol ‣ Floodplain development managed by use of FRAs

7. Land Use Planning Floodplain divided into 3 zones (1- 3) Functional Flood Plain (3b) ‘land where water has to flow or be stored in times of flood’ Limited use – No reduction in Volume, Flood routes Maintained

8. Structural Flood Defences Hard engineering preventative technique Developments in mathematical modelling in the 1980s created powerful tools for flood management Flood Gates, River Walls, Sea Walls, Modification of River Channel etc.

9. Thames Barrier Opened in 1982, costing £365 million estimated to protect £80 billion infrastructure Designed to protect against a storm with return period of 1000 years (up until 2030) Consists of 10 movable gates spanning 520m

10. The Future Global warming: increase in coastal waters, tidal surges and higher intensity rainfall Structural defences too expensive to maintain Increase severity and spread of floodwaters Greater threat to cities as the urban sprawl continues

11. Humber Estuary Current Flood Defences Flood Defences 2060

12. Green Roofs Not a new technology Utilised heavily in Germany 10% of all roofs are ‘green’ Shown to attenuate runoff - reduces runoff rate and flow volume Some studies show a 50% reduction in runoff (Rowe, Monterusso, Russell, 2003)

13. Weather Control? Cloud seeding Utilised in Olympic Games? Not designed to prevent rainfall but to control where it falls by causing moisture to condense prematurely

14. Conclusions Land use planning and structural flood defences currently are major parts of the UK flood management strategy Flood management over the next 50 years looks set to be dominated by global warming Management strategies may have to move from traditional ‘hard engineering prevention’ to a more ‘risk management strategy’