Mr Cobb responded to Nick Xenephon Team candidate for Calare Rod Bloomfield’s comments earlier in the week after Mr Bloomfield claimed a dam was lazy management and investment should be spread across existing dams and groundwater bores to avoid the environmental impact feared for Cliefden Caves.

The Save Cliefden Caves group discovered last year the two proposed Cranky Rock dam options could cause the water level at Needles Gap to rise by up to 50 metres and inundate the caves to a higher level than the original Needles Gap dam proposed by Mr Cobb in 2013.

The group found the caves network was deeper than originally thought.

However, Mr Cobb said favouring greater water capacity from 4200 megalitres to 26,000 megalitres was a step backwards - Cranky Rock has been touted as a 700-gigalitre dam.

“We looked at that [Lake Rowlands] but the problem was there wasn’t enough water involved,” he said.

“We’re going to be a much bigger part of the world in the next 20 to 30 years and we need to give investors the confidence to do this. For the mining that will happen, that’s not a viable amount of water.”

Mr Cobb said more water sources also meant more connecting infrastructure.

“It means you have to have all different infrastructure to supply the same thing and it’s probably not the smartest,” he said.

With WaterNSW currently assessing geological, economic and technical feasibility factors at Cranky Rock and Needles Gap, Mr Cobb said any impact on Cliefden Caves would be uncovered in the report.

“I’m not convinced by all those things anyway. Cranky Rock, as I understand it, is lower than the Needles, so I think it’s highly unlikely that’s true,” he said.

danielle.cetinski@fairfaxmedia.com.au