But without rain, experts predict it won't be long until Lake George dries up into a vast dry plain again.

Visitors have begun to notice telltale signs, with fence posts jutting out and water retreating from the highway.

Heavy winter rains saw the lake fill and attracted tourists with umbrellas and camera phones to witness the transformation.

When the normally barren surface became a small inland sea in 2012, water birds returned to the site and locals began to chatter about using the lake for windsurfing and other water sports.

Ultralight pilot Andrew Luton is a regular visitor and enjoys a rare birds-eye view of the lake level as it ebbs and flows.

He said in 2012 there were only a few weeks before the watery blanket sank into the eastern quarter of the lake bed. But this year was different.

"This time around it has filled up in the warmer months when there is more evaporation and has stayed quite full for a month or two now," he said.

"You can see fence posts poking up through the water the whole way along the lake so it's not very deep and it will be very interesting to see just how long it stays as full as it is coming into summer as evaporation increases."

Professor Emeritus Patrick De Deckker said that when full, Lake George was one of the largest water bodies in inland NSW and could hold about 500 gigalitres.

In the 1860s water was eight metres deep, however, current climate conditions meant that was unlikely to occur again.

"For the lake to retain its level we need more rain, quite a bit more rain," he said.

Professor De Deckker said we were entering a La Nina climatic phase which typically meant the east coast would be wetter.

Yet, there was no certainty when it came to rain and without it, the lake would dry out again within two months.

He said the unpredictable cycle of filling up and drying out meant it was difficult for an aquatic ecosystem to take hold.

He expected fast-growing plankton was already in the lake waters and if more rain fell and the lake was given time to establish, fish and aquatic plants would follow within six months.

"It takes a while," he said. "The lake fills up due to rainfall above the lake but also some of the little rivers east of the lake will bring water and there are little fish growing in little pools in those rivers."

If Lake George survives the summer heat and receives enough rain to keep salinity levels at bay, the area had the potential to support very small native fish hatching in the warmer months.

While the fate of the lake remains uncertain for now, it's clear with all its mystery and magic, this elusive lake continues to keep Canberrans captivated.