10 June 2007The GuardianJuliette Jowit
The cost of protecting London and the south-east from flooding will be at least £4bn as sea levels rise and the south-east coast sinks over the next century, a report for the Environment Agency has warned.
Experts have recognised that the Thames Barrier should be able to guard against the possibility of a major flood until 2030, but say that billions need to be spent on raising 300km of other defences to protect the capital - and even more than that if the sea level rises still further.
At worst, the cost of a major new barrier would be 'in excess of £20bn', says the report by the Thames Estuary 2100 project team.
The report - which goes further than previous warnings - is the latest example of huge bills which face British taxpayers and people around the world to protect themselves from the expected impacts of climate change.
'The more we curb emissions [blamed for global warming], therefore, the less investment will be required in extreme measures to combat the increasing risk from sea-level rise and climate change,' adds the report.
Dave Wardle, the EA's area manager for the Thames region, said the report showed that the Thames Barrier, opened in 1982, had been well designed and maintained, but that the agency would need more money from government in future.
The EA is currently budgeting £200m over 12 years on extra defences, and a Government Foresight report in 2004, 'Future Flooding', called for investment in flood defence and coastal erosion to rise by £10m-£30m a year to limit the average annual damage of flooding to £2bn a year by 2080. Damage is currently £1bn a year, said the EA.
'All research shows more investment in flood defences is needed to take into account the increasing vulnerability of communities facing the unavoidable impacts of climate change,' added Wardle.
The report also said the Environment Agency's Making Space for Water strategy, which aims to find land which can store floodwater, from parks to car parks, could extend the life of the Thames Barrier by 50 to 80 years beyond 2030.
The report's findings are based on the government estimate that the average rise in sea level by 2100 will be 0.94 metres, although it also considered higher estimates of up to 4.2 metres. About 1mm a year of the increase is due to geological changes as southern England subsides; the rest is because global warming is causing ice to melt and seawater to expand, said Professor Jim Hall of Newcastle University, who has advised the EA on flood risk in the region.
'These are pretty conservative scenarios, but London is an important place, so it's important they look at some far-out what-ifs - even if these are not the basis for the design.'
