Is flooding really as big a risk to Britain now as terrorism?

been nothing like the rainfall of last summer, at least in the rainfall records which go back to 1766. June, July, and August, taken together, made the wettest summer Britons have ever seen, and the two critical downpours, which hit Yorkshire from Hull to Doncaster on 24 June, and the area of the Severn valley on 19 July, were probably as heavy as anything Britain has experienced. The trouble is — there are likely to be more of them because of climate change. Sir Michael said that one of the most frequently asked questions during his review was whether climate change was directly responsible for last year’s flooding episodes — and the answer was, it was impossible to say with certainty. New research, commissioned for his report, indicates, however, that there is an even bigger likelihood of such “extreme rainfall events” in the future, because of global warming, than was assumed until quite recently. In 2004 the government published the Foresight Future Flooding report, which sounded the alarm about the heavier rainfall expected in a warmer atmosphere over a 30-100-year timescale. The Foresight conclusions were reassessed for the Pitt Review and they are now gloomier still. For example, in the worst-case scenario, total winter precipitation increases by 40 percent over the coming decades, as opposed to 25 percent in the 2004 projections. The possibility of dangerous sea level rise is also seen as more likely than in the earlier report.

What can be done? A great deal, and the British authorities and citzens need to get on with it, says Sir Michael, who makes ninety-two recommendations for action, and says they should be carried out within two years. In general terms, the nited Kingdom needs to boost the flood-warning system; improve the building regulations; get the bureaucracy right (there is a need to establish a national flood warning center staffed by the Environment Agency and the Met Office); make sure the water rescue system is coordinated nationally; and make sure all advice is consistent. Above all, Britons need to learn to protect critical infrastructure sites and make sure that the authorities are informed on the implications of them being knocked out. Sir Michael says 80 percent of what needs to be done can be done out of existing budgets. It is not so much building new defences, more a question of thinking about the risks in a different way. For example, the 2007 floods threw up what was really a new flooding problem — the effect of surface water. In the past major floods have been caused by rivers overflowing, or, occasionally, by the sea invading the land (as in the catastrophic floods of January 1953, in which 307 people drowned). Although the July floods came from rivers — Tewkesbury, which was cut off, is where the Avon meets the Severn, and thus suffered a double whammy — the very damaging flooding in Hull and Doncaster last June was caused by something else entirely — the local drainage systems being unable to cope with the volume of rainwater pouring into them. This was such an unpredicted risk that no national authority had responsibility for it — as the Environment Agency has long had responsibility for river and sea flooding. Now the agency is taking the surface-water problem under its wing, and local authorities, Sir Michael says, should have a duty to map all their drainage systems, and work out who owns them, who’s responsible for maintenance, and which places are likely to flood.

Can anything be done about surface water flooding? Besides improving the municipal drains? Yes, it would help if Britions stop concreting over their front and back gardens, which decreases the permeability of the land. Sir Michael would like that made subject to planning permission. The authorities can make sure housing developers think about drainage first, instead of last (as Sir Michael alleges they do at the moment). There are very clever modern drainage systems which can get rid of surface water very effectively. Clever, in fact, is what we will need to be to adapt effectively to the soggy future that seems to be awaiting us.