Recent events have highlighted that around the world the frequency and severity of floods is increasing. During the next few decades in the UK, climate change is predicted to result in milder, wetter winters and hotter, drier summers. The fact that the UK has just experienced its wettest summer on record underlines the increased variability of climate patterns. Combined with rising sea levels, these factors will lead to new and increased risks of flooding, particularly within the lifetime of planned new developments.
In response, the UK and the EU have put measures in place to minimise the future risk of flooding, but how effective are these? Is flood risk simply inevitable, and to what extent it can be avoided?
During the past few months, the UK has experienced unprecedented rainfall, with double the monthly average during the wettest June for at least 150 years. This led to severe flooding, particularly in the north of the country, where 27,000 homes and 5,000 businesses had to be evacuated. Seven people died in the floods and the insurance claims are estimated at more than GBP1 billion (USD2 billion).
Heavy rain continued during July, with the rainfall on 20 July alone enough to change average figures of the past 30 years. This time, flooding was mainly focused in the southern parts of England, particularly Gloucestershire and Oxfordshire. Projected insurance claims arising from the flood damage are estimated at GBP3 billion (USD6 billion) and are likely to increase further. It is already expected that insurance premiums may have to rise in response to higher claim costs and there is frustration at the government's failure to invest in strengthening flood defences.
However, the major contributory factor identified to these events in the UK is not the heavy rainfall during July, but the increased building in flood plains. It is estimated that two million properties are on UK flood plains; most of which have been built since 1945.
Further contributory factors were first identified in a government report published three years ago. These include inadequate investment in flood defences and drainage systems; lack of information to householders; lack of a single, over-arching body taking responsibility for the overall control of flood risk; and the need for improved communication between the agencies involved in flood management.