London's 'super sewer' to help stop Thames becoming a toilet

This year alone, 1.2 million tonnes of raw sewage has been dumped into the river Thames because the Victorian sewers can't cope.

Even a few millimetres of rain is enough to overwhelm the old tunnels and anything left over goes into the river.

Work has now started on a new super-sewer that's big enough to deal with the growing population of the city.