Crews were called to Worden Park in Leyland at around 5.48pm yesterday after a jogger spotted the disabled woman waist-deep in a stream.
Two fire engines, from Penwortham and Leyland stations, and a dinghy from Preston, all attended the scene after being called to The Avenue, a spokesman said.
"We helped the lady to safety before she was treated by paramedics," he added.
"When she was released from the stream, she was put in a fire service 4x4 vehicle and transported to a waiting ambulance."
The woman is understood to have been taken to Royal Preston Hospital for further treatment.
The incident lasted around an hour.