Satellite image shows surface water runoff after floods
As the floods slowly subside, in some areas to ground is so wet it can't sink in.
As the floods slowly subside, in some areas to ground is so wet it can't sink in.
A sinkhole has appeared in a street in south London. The Sutton Guardian reports the hole is around three feet deep and swallowed the wheel of a car in Maldon Road in Wallington.
Sinkholes are caused when the underlying rock is washed away - more exactly by the acid picked up by rain water as it passes through rotting vegetation.
That creates cavities underground which streams can flow through - the more water that flows the quicker the erosion.
Read more: Martin Stew explains what causes sinkholes.
The recent flooding has caused an unprecedented number of sinkholes to appear in roads and near people's homes. Martin Stew investigates.
The 600-metre aqua-dam was pumped full of flood water on Friday to protect 200 homes.
Many householders have started to empty their homes and look for temporary accommodation.