The unprecedented rainfall which devastated parts of Cumbria "would have overwhelmed any defence" the Environment Agency said as residents faced up to the damage caused by the floods.

Structural engineers and military experts began an urgent safety review of the county's 1,800 bridges as fears grew that Calva bridge in Workington was on the brink of being swept away.

The town was cut off, with Friday's collapse of Northside bridge and closure of Calva bridge forcing residents to make lengthy detours.

Gusts reaching 55mph and more downpours were not helping the recovery effort but residents were pulling together to "get on with it".

An aerial view of the destroyed Northside bridge, in Workington Full Image

The Environment Agency said river levels across the region were expected to remain relatively high for the next few days. A spokesman said "the phenomenal rainfall would have overwhelmed any defence" and dredging the river at Cockermouth would have made "no difference whatsoever".

He said defences at Cockermouth were raised using a £100,000 investment following the January 2005 floods to protect against a one in a 100 year event. And he said contrary to some reports there were no outstanding upgrades due. Initial inspections of flood defences suggested they were not damaged.

Director of Operations David Jordan said: "The rainfall levels we saw on Thursday and Friday were unprecedented, the highest ever recorded in the UK. They washed away road bridges that had stood for decades and no defence could have prevented the flooding we've seen. While conditions in Cumbria are improving, more heavy rain is forecast and (four) severe flood warnings remain in place."

Andrew Butler, of Cumbria Highways, said a sheer crack in Calva bridge's central arch had grown overnight and the deck of the bridge had sunk more than a foot.

Tony Cunningham, the MP for Workington, said getting to nearby Seaton had turned into a 90 mile journey, adding: "My major concern is residents who are cut off. Things are getting desperate."

He suggested temporary structures may need to go up in the short-term. But he said locals were responding well, adding: "The community spirit is incredible."