Thames Estuary expansion could risk billions in flood damage

Plans to expand London eastwards into the Thames Estuary could result in more than £500m of annual flood damages even before the prospect of rising sea levels is taken into account, according to a new academic study presented at last week's climate change conference in Copenhagen.

Preliminary findings from the study, which was undertaken by Newcastle University and the Tyndall Centre for Climate Change Research, warned that government proposals to build tens of thousands of properties as part of its Thames Gateway project could result in a significant increase in flood risks that will only become more acute as sea levels rise as a result of climate change.

"What the model shows is that if we continue with planned expansion in a business as usual fashion then even without climate change the flood risk would shoot up," explained Dr Richard Dawson, one of the researchers who worked on the study. "If you add in sea level rises at the lower end of the IPCC's projections [of 18cm by 2100] then mean annual flood damages will more than double to more than £1bn a year."

He added that annual costs could be over ten times higher if the latest predictions that sea levels could rise by more than a metre this century prove accurate.

"There is a real concern that the decisions we make today will create a legacy for the next 100 years," he warned. "If this is to be a strategic site for development, and I'm not entirely convinced on the argument that it should be, then we have to think very carefully about the flood risk."

Dawson argued that while it was "bad enough" to locate homes in areas that faced higher levels of flood risk, planners had to be careful not to site essential infrastructure such as hospitals and police stations in flood risk areas.

He added that if development of the area was required to support London's growing population - an argument he said he was unconvinced by – then planners had to put in place an effective storm surge warning strategy and invest in flood resilient building designs, such as buildings built on stilts. "If we have to build there, then we need the right plans in place," he said.

A spokesman for the Environment Agency said that it would publish a detailed plan for development in the Thames Estuary at this end of this month.

However, he insisted that increased flood risks were being taken into account and that the Agency's flood modelling was already based on sea level rises of more than one metre by 2100. "Unnecessary development on the flood plain is something the Environment Agency fights tooth and nail," he said. "There are robust checks in place to stop irresponsible development."