Asked why in certain areas flood defences had been inadequate, Benn said: "Even if those defences had been put in place, they would have been overtopped because of the intensity of the rainfall."
Flooding has effected much of central and western Britain, with Tewkesbury, a medieval market town 180km northwest of London, among the hardest hit with water 1.5 metres deep in places.
Elsewhere, homes and businesses were flooded, roads submerged and trains and buses canceled.
In Gloucestershire, the Severn Trent Water company said at least 350,000 homes would be without water after flood waters shut down a water treatment plant.
On the outskirts of Oxford, 100km west of London, a stadium was stocked with blankets, food and bedding for up to 1,500 people in case the Thames burst its banks. About 50 elderly people had already been evacuated to the stadium.
London itself is protected by a series of flood defense measures including the Jubilee River, a 12km-long flood diversion channel.
|Central and western Britain has seen |
its worst flooding in 60 years [AFP]
The Ministry of Defense said military helicopters had rescued more than 120 people from rising floodwaters, but no deaths or serious injuries have been reported so far in the floods.
Gordon Brown, the UK's prime minister, announced an increase in funding for flood and coastal defenses across the country.
"It is pretty clear that some of the 19th-century structures and infrastructure and where they were sited is something we will have to review," said Brown.
The Environment Agency said the cost of shoring up the UK's flood defences could be as much as £1 billion ($2bn) each year.
Meanwhile, insurance companies estimate the damage from the June and July flooding could reach hundreds of millions of pounds.
The weather facing Britain is consistent with conditions caused by the La Nina weather system, which is caused by cooling ocean waters and leads to extreme weather, Britain's Met Office said.
Some have said the situation matched predictions of how global warming would affect Britain.
Tim Evans, of the Chartered Institution of Water and Environment Management, said: "What we now think of as extreme events will occur more often than in the past, and the extremes will get more extreme."
Joe Giacomelli, a spokesman for the Environment Agency, said: "The situation is looking critical at the moment ... Unfortunately the misery is set to continue."
The last time the UK saw similar flooding was in 1947, according to the Environment Agency.