There needs to be a "complete rethink" of the UK's flood defences following unprecedented flooding across northern England, the Environment Agency says.
Deputy chief executive David Rooke said better waterproofing of homes and improved warning systems would be vital for tackling future weather extremes.
Parts of Yorkshire, Lancashire and Greater Manchester are struggling with the aftermath of downpours that caused rivers to burst their banks.
The PM is visiting flood-hit areas.
David Cameron is likely to face questions about funding for flood defences after some existing structures were overwhelmed.
Image credit: PA