At 12 midday a 31-year-old female from the Melbourne area has climbed over the safety railing on the NSW side of the traffic bridge and threatened self-harm.
The 53-year-old local male witnessed the female climb over the railing from his home near the bridge and ran over to provide assistance.
The Mulwala man then grabbed hold of the female and attempted to stop her from jumping into the lake but she broke free from his grip and fell into the lake.
He quickly responded, removed parts of his clothing and jumped into the lake to rescue the female.
The local man was able to drag the female to a nearby bridge support whilst waiting for emergency services.
The man was able to calm the female and keep her from harming herself further until they both could be rescued.
Local SES crews responded, launching their rescue boat at the Mulwala Water Ski Club boat ramp and were then able to coax the female into their boat.
Both the Mulwala man and female were taken to the ski club where they were treated by paramedics for advanced stages of hypothermia.
Sergeant Grant Churchin from Mulwala Police has heralded the man a hero.
"If it wasn't for the quick actions of the male rescuer the female was in extreme danger of drowning,” Sgt Churchin said.
“I believe that he saved her life."
If you or someone you know needs help call Lifeline Australia on 13 11 14.