Already had a go at diverting water from QLD coast inland ( Burdekin ; Mary Rivers ) basically wasn't politically feasible as any party attempting it would be voted out before it could be enacted.
Economically agriculture can't pay the going rates needed for initial investment in infrastructure and governments don't have the political will to push a couple of snowy mountains schemes at this time.
Other rivers which could be diverted ( pipeline options ) are the Adelaide , Daly and Roper rivers in NT and the ord river scheme in WA. - note most of these 'plans' seem to focus on getting water to the big cities to alleviate shortages but the real benefit is opening up millions of sq km in inland Aus. Will cost billions short term but opens up a lifetime of opportunity and returns.
Food and water will become the important resources over the next 50 years - In the end it will come down to how cheap it is to desalinate sea water as to what will be done in the long term.
