This is the dramatic moment a motorcycle rider and her toddler were swept away by flash floods on a mountain road.

The woman was navigating the waterlogged motorway with her son when their vehicle was caught in a powerful current and dragged downhill in Zhejiang, China.

CCTV footage shows the pair and their toppled white motorbike drifting along the slope on May 3.

An elderly woman, who had just stepped outside her home with her family, witnessed the incident and screamed for help.

As she alerted nearby residents, the rider managed to stop the sliding vehicle at a bend in the pathway.

She then carefully lifted her son and handed him over to a neighbour. With assistance from a man, they returned to retrieve the motorcycle and moved it to the front yard.

Both the mother and child reportedly escaped without serious injury.