A woman was rescued by firefighters from Pennington Brook in Leigh.
The woman, believed to be in her 60s, became trapped on the embankment after getting into the river just after 8.30pm on Monday.
Leigh Fire crew were alerted to the incident after passers by phoned the police.
Watch manager Darren Scott said: "We don't know for sure how she had got into the river, we think she had entered it from upstream.
"She was out of the water when we arrived but she was trapped on the embankment as it is totally enclosed.
"We used a nine metre ladder which we got her to climb on to, to pull her up.
"She was a bit disorientated and had some cuts a grazes on her."
The woman was taken to Wigan, Leigh and Wrightinton Hospital by ambulance staff who treated her for hypothermia on the scene.
She is not believed to have sustained any serious injury.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here