Their best friend was gone.

Her bobbing head had vanished below the raging current that had transformed the usually still waters of Yerrabi Pond in Gungahlin.

Only moments before, Tessa Blight, 13, Emily, 14, and Zartash, 13, were walking with two other friends along a small footbridge over a stormwater drain on the pond's eastern banks.

It was early afternoon on Friday October 12, and heavy rains the day before had swelled the waters rushing through the drain, leaving the bridge flooded to just above the girls' ankles.

Zartash was edging her way along the path, trying to cross a gap between two supporting handrails.

In an instant, everything went wrong.

Zartash slipped and began to fall. Emily grabbed her and slipped, and Tessa grabbed Emily, sending all three tumbling down into the fast-moving waters.

The girls were helpless against the strength of the torrent, which battered them against a group of rocks, before dragging them roughly 60 metres out into the pond's deeper waters.

Emily and Tessa resurfaced, grabbing each other and swimming out of the powerful current and back towards the shore.

But Emily soon realised that Zartash, unable to swim, was gone.

She turned and swam back into the current, while Tessa continued on to the shore to raise the alarm.

''I found Zartash, and pulled her up again,'' Emily said.

''But she was having one of those panic attacks … because she had no idea how to swim or how to keep afloat,'' she said. ''So she was just pushing me down, and there was nothing I could do.''

Tessa, who had clawed her way back to shore, diving down and using reeds at the bottom of the pond to pull herself in, ran to her phone and called triple-0.

At roughly the same time, off-duty firefighter Neil Maher rushed to the scene after hearing the girls' screams while walking his dog nearby.

He dove in and swam to Emily, grabbing her and pulling her from the clutches of the current, unaware she was holding on to the unconscious body of Zartash, who was still submerged.

Tessa shouted directions, and helped to pull her two friends from the water.

Mr Maher and ACT Policing constable Paul Reynolds, who had since arrived on the scene, began CPR on Zartash, and were amazed when she coughed and spluttered back to life.

Emily and Zartash were rushed to hospital by paramedics. Emily, who doctors had feared was suffering from hypothermia, was released in about 24 hours.

Zartash is in Sydney Children’s Hospital. She is understood to have woken from a coma at the weekend, but further details on her condition are unknown.

Recovering from the near-drowning has been challenging for Emily and Tessa. Their return to school was difficult, but they have received counselling to help them return to their normal lives.

‘‘School was really hard to start with – all the questions – but we’re getting through it, we haven’t broken down yet,’’ Emily said.

The girls haven’t spoken with Mr Maher since the rescue, but know exactly what they will say to him if they meet again. ‘‘Thank you,’’ Emily said.