A woman was arrested after being rescued from the canal in Stalybridge, where police said she had jumped in as officers arrived in the area responding to a separate incident.
Emergency services were called to the Huddersfield Narrow Canal at Armentieres Square in the town centre on Monday evening (26 April) at around 9.30pm.
Police had initially received reports of a 'disturbance' at an address on Castle Hall Court.
When they arrived, a 30-year-old woman jumped into the nearby canal.
Firefighters from Greater Manchester Fire and Rescue Service and paramedics from North West Ambulance Service helped her out of the water.
She was detained and taken to hospital as a precautionary measure, Greater Manchester Police has said.
The woman has since been discharged from hospital and arrested on suspicion of a public order offence.