A police spokesman said police were called at around 1pm yesterday (Tuesday).
Police officers attended the scene with fire service as a precaution, in case the man entered the water.
The man did not enter the water and remained on land throughout.
He was left in the care of the ambulance service.
Wellingborough residents posted about the incident on social media yesterday to let people know to avoid the area.
If you ever need someone to talk to, Samaritans are available any time on 116 123.