“The ultimate goal is decentralised water supply and sewerage networks that would be vastly more sustainable and secure than the systems that are failing us now.”

No this is not the ULTIMATE goal. The ultimate bottom line has got be a secure water supply where the demand is easily met by the resource and its supply infrastructure, with a very large safety margin built in to cater for the worst drought conditions.

Pat Troy, like so many others who have written water articles on this forum, thinks at a level well below this.

His biggest flaw is the complete lack of consideration of the rapidly growing number of people that are drawing on severely stressed water resources, in Sydney, SEQ, Perth, etc. This continuous unending growth places enormous pressure on domestic, industrial and agricultural water supplies, and works very strongly against any improvements we can make in the average per-capita consumption of water.

We can install greywater recycling systems, rainwater capture, and implement progressively tighter restrictions and higher costs associated with the public system. And we can build desalination plants and pipelines from the far north. But if we progressively reduce per-capita consumption and increase supply, where will it really get us, if we just sit back and accept continuous rapid growth in the number of consumers?

If the overall scale of human activities was stable or close to it, then fine, we could make real gains. But with the rapid expansion of all things human, it is ultimately just going to lead to the same old problems on an even larger scale!

For goodness sake, all those that are concerned with our water crisis simply MUST put a large portion of their energies into stabilizing the overall scale of activities, so that we can achieve genuine sustainability.

Professor Troy’s criticism of big fixes proposed by increasingly gormless politicians is correct. But are his ‘solutions’ any better?

Composting toilets. Grey water. On-site treatment. Also costly or impractical. Grey water, for instance, is a joke unless you go in for costly plumbing, and there's a limit to how much water you can get from the weekly wash.

How politically popular would it be to make householders responsible for ‘harvesting and treatment of their own water’? We all know the answer to that one.

Allowing households 20kls per person per year is a beauty, given that one person uses 1 kilolitre per week now. What sort of ‘harvesting’ and ‘treatment’ gear would be needed to find the rest? Totally unworkable and naïve!

Another dreamer.

We still have to rely on rainfall, which money cannot buy. All we can do now is hope that the predictions that the drought will break in March are true. We cannot rely on politicians and academics for answers.

Remember, these are the same people who have pushed for high immigrant intake which has seen Australia’s population double its sustainable limits.

Lack of foresight in the storage of water, and too many people, will be seen as the real problems by future generations.

Good post, Pat. The average household uses slightly more shower and bathroom sink water than they use flushing the toilet. And these volumes are used consistently and in the same proportions. And this enables the capture of only one days shower water in a very small (120 litre) tank for re-use the next day for flushing the toilet. This will cut the average household consumption by 25%.

An additional 120 litre tank/drum can be put, either on the roof or bolted to a wall, above cistern height and a small, $30 aquarium style pump is all that would be needed to shift the water from the tank/drum below the shower to the top tank.

And over a year these two little tanks would save the average household about 44,000 litres. The secret to their efficiency is that, unlike conventional tanks that capture rain water, these little guys will fill and empty 365 times each year. A dam, in contrast, fills and empties once every 8 years.

But a combination of rainwater tanks and bathroom recycling can achieve full self sufficiency in every capital city at 80% of mean annual rainfall.

And by adding one smaller tank that is fed from the mains system, the limited supply of 20Kl of potable kitchen water could be delivered on a continuous, low pressure, drip supply by pipe systems that are so small, and light weight, that they could be attached to your overhead internet cable.

The plumbers wouldn't like it because they do very well out of digging very expensive holes in the ground to install and maintain a pipe system that uses technology that was state of the art in 1905.

I understand that one form of this sort of system has already been implemented on a housing development at Beaudesert.

Where are the costings?

It makes little sense to suggest that doubling the price of water could have a significant impact on low earners, but then to propose alternative solutions that have an even greater impact on the real cost of the water. The effect on cost exists even if it's not shown in a water usage bill, but instead appears in increased mortage interest or rent as a result of a higher capital cost of housing.

The cost of retrofitting existing housing stock with rainwater tanks and grey water recylcing systems would surely exceed the cost of building a large scale desalinator or potable water recylcing system with the same effective yield. Accordingly the large scale systems are the way to go.

Raising equity issues here is a furphy anyway. The solution that is adopted should be the one with the lowest cost commensurate with the whatever environmental goals are agreed on. If the result is an untenable increase in cost for some section of the community, then that equity issue should be addressed directly, with cash. It should not be used as an input into the decision on which solution to adopt.

Sylvia.

Perseus, nice to see someone putting some numbers to a practical solution.

My solution runs along a slighly different track, although it could be used in conjunction with yours to water the garden.

Asssuming a household of four people, a roof area of 23 squares and and average rainfall of forty inches per year, an average amount of one thousand litres per person per week would be available. Assuming a typical Melbourne eastern suburbs rainfall distribution, this would require a total of ten thousand gallons (forty thousand litres) of tanks). Cost about four thousand dollars plus pump and plumbing of about another thousand dollars.

If the twenty thousand litres was added to the system each summer, there would be no water running to waste.

If recycling was added, you would be laughing.

Apart from the effects of a long term drought, it has been the growth of cities, particularly coastal cities, that now see urban populations always accustomed to abundant supplies of water, finally experience some of the deprivation normally encountered by country people during droughts.
This growth of city populations is only partly related to immigrants moving to Australia. For over 50 years the country towns and districts have been losing their population to the cities. If Australians prefer to live in the city, so will immigrants.
Why do country towns and country farms have empty houses? Answer, because there are not enough jobs, sealed roads, services available in rural areas. As a result, people are placing a strain on areas where these facilities are readily available.
Country people have always provided their own rainwater tanks, grey water storage and sewerage facilities. They have to be responsible for telephone lines and electricity lines across their land. They often have to drive their children many miles to school, or send them away to boarding school at great cost.
Mothers have to go to cities weeks ahead of their baby's birth to ensure medical assistance, leaving younger children and other family members to cope without them.
Fix the problems of the country so that people want to live there, thus reducing the demand for city accommodation, super highways etc. and issues like a shortage of potable water will quickly vanish.