Seeing that the country is run under competition policy, one where the market rules, it would be consistent to have water brought into line.
As long as productivity gains of 1.2% can be maintained, then water will continue to be available subjected to the present rate of diminuition; externalities excepted, of course.
It needs to be no less than that rate, because it just matches Australia's population growth.
In 55 years (2060 near enough) we would have twice the present efficiency: just what is needed to maintain the status-quo for water-per-capita. In the absence of any alternate economic approach, the need for such efficiencies will be required to continue. The future impact of the current downward trend in water matters can be regarded as an externality.

In keeping with the predominant economic paradigm of ignoring such externalities, others such as predicted decrease in rainfall and increase in evaporation will also be ignored for articles such as this one.

Water re-cycling is still a long way off from being affordable for the average person. Until then, another alternative would be to relocate or build new dams in locations where average rainfalls are highest. Weather patterns have changed and as a result catchment areas are no longer in the best location. This would be an expensive government initiative but would have long term state/national benefits. Australia doesn't want to be backed into a corner, paying exorbitant fees for re-cycled water or our dams running dry. We need to look at other alternatives. We think back to Mexico and how they were backed into a corner and had to act quickly to save lives. With the cholera outbreak in Mexico which was the result of the main water supply being infected, the government made a massive investment in re-building the pipelines and so saved millions of lives and improved the general health of the citizens. We are not experiencing cholera, but what is similar about the Australian and Mexican story is that our water supply is limited. Let's look at dam re-location.

The Howard Government has a proud history of dam construction and water conservation programs. Tully in North Queensland, Australia's wettest town has had a water bypass system in place to divert water into a huge resiviour, so it can be used for crop irrigation, and drinking water for the whole of North Queensland, a great start to increase water stocks on the dryest continent on Earth.....um! Sorry I was only dreaming, they have done very little indeed!

There are two more ways to improve sustainability of water supplies,

1 improve the efficiency of the catchment, and
2 move the catchment to maximise rainfall and runoff.

A typical forested catchment only collects 5% of its rainfall. The rest is used by the vegetation cover. The taller and heavier the vegetation the lower the runoff. A house roof, a supermarket roof and parking lot, an airport or a road all have close to 100% runoff efficiency. Very little rain is evaporated or used by the surface covering. So a shift from using forested catchments to using roofs and pavement will generally produce a 20 fold improvement in supply from the same area.

Put another way, a roofed catchment need only be 5% of the size of a forested catchment to deliver the same amount of water. And this enhancement in the efficiency of catchments can easily offset reductions in the efficiency of storage infrastructure.

A house with less than a 9000 litre tank is really just lip service to self sufficiency. The larger the tank the cheaper the storage. A 9000 litre tank costs about $1,500 while a 27,000 litre tank costs only $3,000.

I am thoroughly sick of the incredible blind spot that so many thinking people have with population growth.

Kevin Cox writes about sustainability and reduction of demand. But despite this he fails to entertain ANY thought of limiting population size or even reducing the rate of growth. He writes; “… the future supply of water (both fresh and recycled) must be sufficient to meet the needs of a growing population.”

He just sits back and accepts that rapid population growth will continue unhindered. Well…. how on earth can he dare to talk about sustainability, or dare to even suggest that better water-use efficiency will reduce demand if the number of users is going to rapidly increase with no end in sight? Give me a break!

In most cases, the implementation of better recycling or overall water-use efficiency will simply allow more people to live under the same water resource. It will just lead to an exacerbation of the situation….. unless the other half of the equation is dealt with as well – population stabilisation.

“recycling is necessary for long term sustainability but is rarely economically justified in cost terms when compared to the cost of fresh mains water.”

Firstly, the words “long-term” are redundant. Anyone who knows the meaning of sustainability would realise this.

Secondly, NO…. recycling is NOT necessary for sustainability!

Matching the demand with the supply rate, while leaving a very comfortable safety margin, is what we need for sustainability. This does not necessarily include recycling.

By far the most important thing to address is the ever-increasing demand

Ludwig, the rest of us are sick to death of your population "dogs vomit" that you keep returning to. Most rural houses in Australia get all their household water needs from tanks smaller than 27,000 litres. Such a tank, according to my catalogue, costs $2,900 and the annual interest on this, at 7% a year, would be $203. And as the average home has 2.7 people in it then this works out at $75 per person each year.

This is the price of self sufficiency in household water in perpetuity. In contrast, the average income of an Australian is about $50,000 a year so lets get all this so called "water crisis" in perspective. The cost of self sufficiency is not 1% of average income, it is only 0.15 of 1% of average income. The average worker covers their annual water costs from working for only 3 hours a year.

But you and your sad and miserable bunch of lilliputan ideologues want to impose draconian population controls, to reach your grubby fingers right into the bedrooms of ordinary Australians, on the basis of a supposed crisis in the supply of water that might drive the cost of this water above the price of two slabs of beer.

Please, find the rock from whence you crawled and get back under it where you can no longer be a public nuisance.