The word that we need to find here is "sustainability". Water is not necessarily an infinite resource, hence the degradation of the Murray River, though competent management can minimise the impacts.
The Californian fruit growing industry is entirely unsustainable, relying on a diminishing water supply and a labor force of immigrants (some illegal) working for, at best, a minimum wage of $US7.50 an hour (that's $US300 for a 40 hour week...). Plus federal subsidies.
The Chinese have over committed their water supply already, and are busy poisoning what is left.
I'm unaware of the situation in South-Eastern Europe and the Middle East with regard to water, but, for the most part, labor is cheap, though water may be scarce.
I should like to know more about horticulture in Southern Africa and South America - the latter has had little impact here, as yet.
Tropical and cool temperate fruit growing is, I suspect, rather more independent of limited water supply. While the former has very inexpensive labor, the latter is highly mechanised, regulated, and approaching sustainability.
The outlook is bleak for stone fruit orchardists world wide, until the least sustainable regions collapse, leaving only regions with good quality management - and for that we will have to pay sustainable prices for tinned fruit, well in excess of what we pay now.
As for who owns the canneries, does it really matter. We all live on the same planet, and if there is a real quid to be made, then new canneries will be established.
While we can look at a lot of this as scare mongering & put down the call for retentions of the various Australian companies, along with production here, & say that we are part of a global village etc, it will not take long to find as many of the O/seas companies who are also looking at our land & what remains of our companies, that they will end up taking the produce from the land they own.
One only has to look at the current auction that is going on to take over control of the Warnambool Cheese & Butter WCB, with China now making a bid, the reason to secure the future provisions of the products from there. Its not a matter of just the water & its sustainability, its more to look at producing food for the overseas market, & when overseas companies especially those owned or part owned by their governments, they can control what they want especially if they own property with the water that's needed.
The case point of water is how much is needed to grow cotton, with at least the huge Coby Station in QLD going to overseas interests, rather than grow cotton, they can use the water for food, as well as sheep, which provides both food & wool for clothing that replaces cotton, which also wrecks the land. As they have rights to the water, they will use it, denying those downstream more than they do now.
Stone fruit can survive easier than you think, many of the newer varieties are more able to sustain dry periods than the older varieties.
In the end though, with all these companies buying out the businesses just to close them down & import from overseas, once complete, the cheap prices will disappear, the overseas cheap labour will be the same, but the unemployment here will be much greater, with many of them being forced to life under 3rd world conditions, meaning this country will be as bad as so many others were, & will remain, who we used to be able to support during droughts & famine, that is the wonder of equality where two tiers exist, & the world goes back to the feudal system of England, when you swore loyalty to the Lords & their predecessors in order to be given food & subsistence.