This is the dramatic moment rescue teams saved a grandmother washed away by powerful currents in a Thai river.

Boonhome Rawelee, 57, was walking home along a bridge when she slipped off the deck and fell into the Phong River in Khon Kaen, northeast Thailand on Monday.

She was swept some 500 metres (1,640 feet) downstream before pedestrians near the embankment noticed her struggling to stay afloat in the water.

Emergency crews were dispatched to rescue Boonhome as the river carried her farther away.

Footage shows the grandmother sinking into the river as roaring water cascaded from a nearby weir. Emergency personnel later arrived and found her drifting unconscious.

They managed to drag the middle-aged woman onto a jet-ski and take her back to the riverbank, where her worried niece was sobbing as rescuers lifted her into an ambulance.

A rescue officer said: 'After we grabbed her and pulled her up to the jet ski, we called out to her, but she was initially unconscious.

‘After calling her several times, she responded by blinking, so we informed other rescuers to bring another jet ski and a boat to rescue her before she could drift further away, where the water was deeper and more turbulent.'

Boonhome's niece, Thaninrat Naenudon, 51, said she believed Boonhome had jumped from the bridge.

She said: 'We were still able to talk in the morning, when we were preparing to send my nephew to school. She asked me to take care of him if anything ever happened to her.

'I was surprised when she spoke like that. It was the last thing she said to me before dropping my nephew off.

'I was shocked by what she did. She never showed any signs of trouble, apart from occasionally borrowing a few hundred baht for my nephew when money was tight.

'This whole incident has left me shaken, because there was no sign that anything was wrong, and as far as I knew, there were no problems at her work.'

Local media reported Boonhome was recovering at the Nam Phong Hospital, where she was being monitored by her family.