The person is now recovering in hospital for the effects of water shock and hypothermia.
Foyle Search and Rescue say on its Facebook page: “At 7.22 pm on Friday, April 17, Foyle Search and Rescues Pager system was activated by the Police Service of Northern Ireland to reports a person had entered the water.
“As Teams were responding members of the public assisted a person from the water to land.
“PSNI arrived on the scene along with FSR First Responders, an EMT and an Ambulance Service Paramedic who treated the person for Cold water shock & Hypothermia.
“The person was then removed to hospital by Ambulance.
“All our Emergency Response Team were debriefed and stood down at 8.15 pm.
“FSR would like to acknowledge the help of the public.
“We understand this may have caused you distress.
“If you wish to speak to someone there are some helpful contact numbers below:
Lifeline 0808 808 8000
Samaritans 116 123
CCIS 02871 26 2300.