The girl, 16, was taken to hospital for checks after losing feeling in her legs following the incident off Longsight Lane, in Harwood, Bolton.
Firefighters, Bolton Mountain Rescue Team and a water incident rescue boat were called to the scene near Bradshaw Brook.
It is understood that the girl had gone down the banking to retrieve a mobile phone.
A fire service spokesman said firefighters used specialist lighting to locate her in the dark.
She said: "The fire service was quickly on the scene and she was carried to safety using a specialist spine board."
The girl was taken to the Royal Bolton Hospital with suspected back injuries.
Mountain rescue team leader Gary Rhodes said: "We turned up after being called by the ambulance service but the girl was being dealt with.
"She was with a group of friends and they raised the alarm."
Tweet
