Dramatic footage has emerged of a farmer being winched to safety from a swollen river, as floodwaters rise and heavy rain continues in Canterbury.

The two-minute video, posted to Facebook by Hoops on Air radio station this afternoon, shows a helicopter hovering above the raging river below where a lone figure is standing trapped in the floodwaters.

The helicopter lands and the individual climbs aboard before the helicopter takes off.

Six people tending stock have also been trapped by rising floodwaters in the Foothills Rd area at Okuku, North Canterbury.

A police spokeswoman said they had been notified of people trapped in this area, and Fire and Emergency were assisting Search and Rescue and police.

The six have now been airlifted to safety by helicopter.