Water is a problem for most countries but I have been very impressed with how Australia have responded to the coming water crisis. We have just gone through a drought in Victoria but with the desalination plant they built a few years back we didn't have any issues... not that we can afford to become complacent The biggest water problem for us, I believe, is the Murray Darling Basin where fish are dying off in droves... it's a shocking crises and I would put that above the laser beam Koala crises The other issues we are facing is housing, house prices are stupid high, high debt levels, in Sydney there's an overpopulation issue ito infrastructure... also in Melbourne but not as bad as Sydney. Here's my list Murray Darling Basin (water) Infrastructure Housing affordability Debt levels cost of living
Forgive me but given Australia's huge size the idea that our Aussie cousins would suffer from overpopulation is somewhat spurious.
I voted for the Koala bears, but first they have to get rid of their chlamydia problem. And some Aussies think WE have problems...
I've never been to Australia (although I've always wanted to visit Perth), and I don't know squat about what's really involved in desalinization processes. But I've understood that Australia is a fairly arid country, so, if civlization ever really masters desalinization technologies it could be very helpful to Australia, which, of course, is completely surrounded by oceans.... Outside of that... hell, I don't know. If too many people move there they might 'love it to death', like they tend to do to every other part of the world that isn't already a 'shithole'....
Australia is a land of contrast, the North East (Queensland) Suffer from major floods almost every year, while other parts suffer drought. The north experience monsoons every summer and the south receives it's rain during winter. In the Tropics and sub-tropics (north) the seasons tend to blend, 9 months of humidity and heat and 3 months of cool weather... while in the south the seasons are clearly defined. The coastal areas are beautiful and this is why most Australians live around the edge of the Great Southern land. Unfortunately you are correct about the "too many people" infrastructure in Sydney and Melbourne are under pressure from recent high migration numbers.
In the next fifty years some of the world's richest people will be the ones who have successfully found inexpensive ways to create desalinization systems. Australians will likely be some of the bigger customers for systems like that.
Desalination is not a solution, crazy energy costs, very inefficient, stupid co2 per litre. Don't move 50 million people to Australia is the actual solution, fresh water is going to be the next big thing.