Just weeks out from the release of the guide to the future-shaping Murray-Darling Basin Plan, it has been revealed international investors - who have already ploughed hundreds of millions of dollars into the Australian water market - were planning a further assault once the plan was finalised.

In this area alone, 18 per cent of water entitlements have been snapped-up by the government and outside investors.

And that's just the tip of the iceberg, according to local businessman and chamber of commerce spokesman Paul Pierotti, who said permanent water trading was an attack on the future viability of the region.

"Would these foreign investors be buying water if they didn't think it would seriously increase in value; of course not," Mr Pierotti said.

"Once the (Murray-Darling) plan is released and once the government