A man is recovering in hospital after he was rescued from the water at the Glenmore Reservoir by a passerby on Tuesday morning.

Margaret Bell was walking along the reservoir when she saw an empty boat sitting near the shore in North Glenmore Park. As she approached the shoreline, she noticed something in the water.

She thought it was an animal but realized it was a man when she took a closer look. She went into the water and pulled a man in his 20s to shore.

Bell says she goes on a walk every morning and that she was just in the right place at the right time.

“I thought it was a beaver floating in the water but as I got closer I saw it was a person and I thought oh! I better go help,” she said. “He was on his back, he was trying to swim, he would go over and then he would go under a bit.”

Bell then flagged down a cyclist who called 911 while the she returned to the man.

“He didn't really have an answer as to why he was in the water. He was hypothermic, he was profusely shaking, his lip were quite discoloured,” said Bell.

The man was conscious and breathing when fire crews arrived and he was taken to hospital in stable condition.

“We have a good response time but still five minutes can make a difference so she jumped into help. And she knew what she was doing,” said Carol Henke, CFD Public Information Officer.

Fire officials say the boat found near the man was not his and it is unclear if it is connected to the incident.

Investigators are trying to determine how the man came to be in the water.

Officials say the woman's selfless actions contributed to saving the man's life and she will be recommended for a Calgary Fire Department 'Beyond the Call' award.