John Holliday, who is renowned for discovering the gold at Cadia, visited the school with daughter and soil scientist Pandora to teach the students about the basalt aquifer, which holds the groundwater feeding the area's bores and is recharged by its swamps and swamps and wetlands.

Ms Holliday made a layered cake to show how dyed blue water could penetrate sponge cake, but not the jelly layer, symbolising the different rock layers.

"We went through the geological history of the rocks around Orange - the really old basalt, which has the Cadia mineralisation, and the new basalt, which hosts the aquifer," he said.

"It's a pretty valuable resource and we're hoping it doesn't get overused or damaged."

The old basalt, which came from underwater volcanoes, is 440 million years old while the 'new' basalt layer is up to 13 million years old following an eruption from Mount Canobolas.

The water travels north where it links up to Orange's water supply, although its exact path remains unknown.

It followed an earlier workshop at Spring Terrace Public School, with a $200 donation from Orange City Council to the Spring Hill and Surrounds Community Consultative Committee.

The committee opposed an industrial business park at Orange Regional Airport in 2017 due to concerns about the impact on the aquifer.