An article in today's Daily Telegraph http://www.news.com.au/dailytelegraph/story/0,22049,20459706-5001021,00.html
describes how some councils have had to close their sports ovals for the summer, and others are restricting the activities that can take place on them. The reason for this is that Sydney's level 3 water restrictions mean that councils cannot use the water they need to maintain the ovals in a condition suitable for use.

The cause of this is not the current drought conditions, though obviously they are a contributing factor. No, the cause is the state Government. The Government's own cost estimates for a wind-farm powered desalinator show that water from a desalinator costs about 50 cents per kilolitre more than water from the catchment areas. At the moment it looks like we'd only need to produce 1/3 of our water that way, so the net impact would be 16 cents per kilolitre. With per-capita usage running at less than 300 litres per day, this would mean an increase of about 5 cents per person per day.

The government's current approach to handling the water shortage is to do as little as possible to avoid Sydney actually running out of water. As a result we can expect to stay on level 3 restrictions indefinitely. Yet I do not believe society is unwilling to pay 5 cents per person per day in order to get rid of water restrictions. If the government weren't totally spineless, they'd have started building the desalinator already, rather than pussy-footing around with half-measures like deep water access to the dams.

Sylvia.

I'm no scientist, but yesterday I heard a scientist saying that the water restricitions placed on the population have no validity in science.

Governments have sat on their hands for years, preferring to 'punish' the rest of us with restrictions and threats of high cost water to get us to use less. At the same time, they are bringing more and more people into the country.

A couple of years ago, after questioning the SA government on the sense of trying to increase the population when we supposedly did not have enough water for the current population (SA has had permanent restrictions for some years) I received a glossy brochure to do with 'waterproofing' SA. The idea was that we could increase population and still have enough water through government initiatives.

What has the government done since then? Sweet nothing! And next month we will have further restrictions imposed on us.

We are still being told, though, that SA needs a further half million people to feed voracious industry.

Agreed Leigh

Currently, with the continuous growth paradigm still firmly entrenched, any increase in water restrictions or any increase in water-provision will directly facilitate more and more people moving into water-stressed areas.

This will serve to dilute if not completely cancel out these measures.

Population stabilisation is thus one of the vital prerequisites to developing secure water supplies.

Continuing to increase populations in water-stressed areas is just madness.

Currently, it is not a case of us all having to do with less for the good of our city, region or country, it is a case of us all having to do with progressively less so that more and more people can be squeezed in.

When is this insanity going to change?
.

Sylvia, I don’t have too much of a problem with the promotion of desalination plants, for as long as population stabilisation is part of the overall strategy.

Leigh, it is certainly true that the restrictions have no scientific validity.

In the past the only practical way people had to obtain fresh water was to take it from rivers, capture runoff in dams, or take it out of the ground (springs, wells and bore holes). This seems to have become embedded in the mindset of politicians as if it was a universal principle.

In more recent times technology has provided other solutions, but governments still seem stuck in the past.

The result is that the NSW state government's approach for Sydney is to take yet more water from the Shoalhaven river, and if that's not enough, drill bore holes. In both cases, we're sucking the lifeblood from the evironment. It seems that only when we've bled the environment dry will the desalination solution be adopted.

Ludvig, I think it would be difficult to stabilise the population at this point without significant adverse economic consequences. The problem is our aging population.

It's true that an increased population will necessitate increased desalination, which in turn will push up the net cost of water, because a greater proportion will come from desalination. However, the effect will be gradual, and really isn't that large anyway. I think the ecomonic cost of not having the population increase would outweigh the higher costs of water with the extra people.

Sylvia.

Sylvia

I would say that the problem is our overall population size in relation to our resource base and our way of life.

I don’t think the aging of the population is a particularly significant problem at all.

Stabilising population is something that we must work towards. It would indeed create problems if we just did it overnight, ie, stopped immigration, and transmigration into growth-stressed areas. A gentle approach to limits for the country, states, regions and cities is in order. These can then be open to regular review. The important thing is that we get it through our thick heads that we can’t just keep growing indefinitely, and that maintaining the same rapid growth rates in times of resource stress simply defies logic.

It seems to me Sylvia that you are putting the economy ahead of quality of life. Fast growth rates lead to a dynamic economy and a progressivley bigger economic turnover. But if this is based on population growth, which it very largely is, then what’s the point? We must think of economic turnover in terms of the quality of life that it provides. So we must think of it in average per-capita terms, not in gross product terms.

So yes, a slowing of population growth will inevitably lead to a slowing of economic growth. But it shouldn’t lead to a reduction in per-capita economic growth. So therefore it shouldn't matter.

Building more desalination plants will probably provide adequate water for a much larger population at a tolerably more expensive rate. But the continuous population growth facilitated by a program of simply building more and more plants would apply pressure to various other resources and add to all sorts of environmental problems.

Surely it is a much better plan to limit the demand for water, ie size of the population, rather than ever-increasing the supply rate, or increasing supply until the population size comes up against some other limiting factor.

Great topic Sylvia.

My 2c - it would be impossible to run out of water if price was determined by market forces.

Price above minimum daily household requirements should be sold to the highest bidder/s. Yes, we'd pay more if we were wasteful, but once the current atificial price ceilings were lifted this would lead to reduced demand through innovation and conservation (cost-avoidance) on the one side, and increased supply on the other side as infrastructure / technology / production costs would be better met by higher profits.

Foundation,

I certainly favour a free market in water. It just seems to be difficult to devise one that works. The underlying problem is that the suppliers with the lowest marginal costs are the catchment operators, but the amount they can supply is unpredictable.

Suppose I discovered that 25% of the people in Sydney were prepared to pay a modest premium (50c / kilolitre) to have a water supply they could use as they liked. I might be tempted to build a desalinator to supply that demand.

All well and good. But what happens the Sydney catchment area gets flooded next month, filling the reservoirs? Water restrictions would be lifted. My customer base would vanish overnight, followed almost immediately by my bankruptcy.

Faced with such a risk, I would never be able to get financing for the project in the first place.

So I really need to get my customers to commit themselves for the life of the desalinator - 25 years. In practice even that is problematic, because people die, move to different cities, etc. My best thought so far is that a property owner could commit the property, so that whoever happens to be using water in it would have to pay the premium. That could be administered by the water distributor.

An alternative would be to say to the Sydney Catchment Authority that come what may, they will not be allowed to supply more water each week than they're supplying now. If that means increased 'environmental flows' than so be it. However, could any private enterprise trust the politicians to stick to that?

Sylvia.

Ludvig, I wasn't thinking about the total economic product. The problem of an aging population would exist even in a nirvana where money was unnecessary.

The reason is that any service that is to be provided to you has to be provided by someone. This is true whether it's medical care, someone to repair your roof, or maintenance of your car. If there are many people who are too old to provide these services themselves, and not enough younger people who can provide them, then people are going to have to do without, nirvana or not.

So while it's clearly not viable to allow the population to increase indefinitely, getting it to the point where it's stable has to be done with some care, and certainly cannot be achieved quickly.

Sylvia

Sylvia

I agree that population stabilisation has to be undertaken carefully.

But the important point is that it has to happen, and with some urgency

Let me say this. Put one bucket in the rain = 1 Full bucket of water.
Put 2 Buckets in the rain = 2 Full buckets of water, not 2 half full buckets.

There is plenty of water. Watch billions of litres run down the drains and out to the sea when it rains. There is the same amount of water there always was on Earth. We don't have enough buckets (dams)to cope with drought periods. Except of course in Newcastle where there is NO WATER restrictions and never have been and the dams are at least 80% full even during the supposed "drought". Newcastle is now sending water to the Central Coast and Sydney.

The rainfall is the same as Sydney and the Central Coast.

Go figure.

There is barely enough water to maintain status quo. Any plan for an increase in population must include an expansion in water catchment and storage. I see more dams as the only solution. Desalination on a large scale is far too energy demanding. It's illogical to talk about the greenhouse effect and at the same time fire up huge power plants to drive desal plants. Even environmentalists will have to concede that to dam a valley has far less environmental impact than to run more power stations.
No-one wants more power stations and dams and infringe on even more of what little is left wilderness but far too many want to bring more people into the country and have more growth. Share holders want more profit, shoppers want more and better food on the supermarket shelves. All of this requires more water.
Unfortunately, the want more society is working itself into an inescapable corner.
My logic might be way off but i'll air it anyway. Like it or not people too are part of nature and can be dealt a hefty blow by nature as we do to her. If the continent is too dry to support any increase in population and we don't want to interfere with nature any further then let's not have a population increase. Ok. If we do want more water than we have to interfere with nature, period ! It's how we interfere that's the question. Ever heard of the Bradfield scheme ? No ? Go and Google it. makes sense to anyone with sense. How about flooding Lake Ayr ? The resulting evaporation from such a huge expanse of water fresh or salt, could quite possibly cause a weather pattern resulting in the greening of much of the presently arid interior. To flood Lake Ayr would not entirely be environmentally unacceptable considering that it does flood naturally occasionally. The solution is staring at us but because of our political system ie. tunnel visioned, revenue ravishing minority groups dictating a supposed democracy, the problems will increase in pace with the demand for water

"Desalination on a large scale is far too energy demanding"

Such vague claims contribute little to the debate, and can seriously derail it.

Let's discuss things in concrete terms. Suppose we want to increase Sydney's available water by one third. Sydney's daily water consumption is running at about 1400 meglitres per day. So, one third of that is 466 megalitres per day, or 466,000 kilolitres per day. Desalination of seawater takes about 6 kilowatt hours per kilolitres, so our hypothetical desalinator would have to consume 2,800,000 kilowatt hours per day, or 116,666 kilowatt hours per hour. Of course that's just 116,666 kilowatts, or about 116 megawatts.

By commercial generation standards, that's not much. The average NSW power consumption is somewhere above 7000 megawatts. The power for the desalinator could be generated (on average) by one windfarm like this one:

http://www.theaustralian.news.com.au/story/0,20867,20395404-643,00.html

So that's the reality. We could increase Sydney's water supply by one third without any increase in CO2 emissions by building a desalinator and a wind farm.

Such vague claims contribute little to the debate, and can seriously derail it.

well, in theory the kilowatt figures appear reasonable but in reality, the scenario does change. by increasing water availability EVERYTHING else increases as well. more water=more industry=more polution and that's not a theory. on top of that sylvia are you aware of how much concentrated bacteria laden reject water is going back into the ocean ? two thirds of water going through the membranes are reject. have you any inkling what this does to the marine life and coastal vegetation ? google it if you don't think i have no idea. i work in that industry. desalination is a short term solution and only acceptable on a small scale. machinery requires constant upgrading and servicing which always involves poluting agents.
a dam on the other hand is far less maintenance intensive and even provides much needed good recreational value. imagine, the hard thinking theorists could even go for a swim and cool their hot heads.

Pragma,

I take you're annoyed that I've undermined your argument that desalination is too energy intensive. So now you've decided to raise other issues, but again without providing any concrete data.

Regarding the alleged bacterial problem, desalination doesn't increase the number of bacteria, just their concentration, It also increases the salinity, which some of the bacteria will no doubt not survive. Anyway, bacteria are not an inherently bad thing. They are part of the food chain.

I don't doubt that the more concentrated salty water has an effect in the immediate area where it's released, but it's not as if dams are innocuous in that respect, because they destroy habitat for land animals and plants. In any case, there are limited options for building new dams. You can't just build one anywhere.

The fact that desalination plants require maintenance is just a cost of production. A plant has a definite life after which it needs to be scrapped and rebuilt. This is also just a cost of production.

You have not provided any evidence that the maintenance necessarily involves pollution.

sylvia i appreciate your reply. desal membranes require periodic (3mths min. dep. on raw water quality) chemical cleaning with alkaline and acid cleaners at a rate of 20/100. the pumps require substantial oil changes ie. a 50 tonne/day, 30 kw high pressure pump has an oil capacity of 8 litres. it goes without saying the bigger the pump the more oil. the primary and secondary filters also require frequent replacement although there is no apparent chemical pollution from discarded filters they still need to be manufactured. membranes have a very high failure rate in the manufacture process and that also is a substantial contributor to pollution. the internet as you are well aware, provides all the info you wish to find. i am by no means a raging greenie however, it is my view that the threat to our athmosphere is far less from a dam than from the emission of oil based machinery and so-called environmentally friendly technology distorts the grim reality of the high pollution rate from it's mainly oil-based manufacture.

btw no-one actually argues that dams have no impact. they just have less impact. whilst some wildlife habitat is obviously submerged it is not destroyed as such. wildlife is adaptable and relocating up the slopes is not without consequences. natural cycles do not revolve around wildlife. wildlife adapts and revolves around the cycles of nature as it does with much of human interference. the most important consideration for us to concentrate on is the minimising of the impact. we can not eliminate any impact unless we eliminate ourselves. step forward the hardened conservationists ! :-)

Pragma, wildlife includes much more than just the mobile fauna. What about all the plants?

“Whilst some wildlife habitat is obviously submerged it is not destroyed as such.”

The submerged habitat is destroyed. How can you argue otherwise?

“The most important consideration for us to concentrate on is the minimising of the impact.”

Absolutely. And this is why it is of vital importance to declare limits to the size of us. ie, the population… and hence the demand for water and all sorts of other resources.

The very fact that we are considering things like desalination plants means that we have grossly overstepped the point at which humanity should have stabilised its numbers in places like Perth and Sydney….. and yet we just keep on growing. Crazy stuff!

It is far from clear to me that a dam has less net impact on the environment than a desalinator of equivalent capacity if the CO2 aspects of the desalinator are eliminated by way of sustainable power generation.

There is not just the permanent flooding of the land, but a reduction in flows downstream of the dam. There is also an elimination of periodic temporary flooding downstream, and a cessation of passage of silt.

The silt also eventually fills the reservoir rendering it useless, so dams are not sustainable in the long term.

However, in the case of Sydney, the issue of whether dams are better or worse than desalinators is largely moot, because of the absence of suitable places to build new dams. The question is really whether Sydney residents would prefer to have a desalinator built, or endure the current level of water restrictions indefinitely, with the consequences such as the one I discussed at the start of this thread.

This should be a community decision based on facts. At the moment, the community has been fed half-truths and misinformation by people with a different agenda.

No offence, but I find it rather strange that the relative effects of dams and desalination plants and the like are being discussed here, while the impact of a rapidly growing population is the factor that is really generating the significant impact.

I think that this is basically the wrong sort of thing to be discussing with respect to the overall water-supply issue.

Let’s take the hint from this national water crisis, or what is developing into a crisis, and get ourselves off the continuous growth paradigm and onto the path towards genuine sustainability as quickly as possible.

Let’s not get tricked into discussing the best or most efficient ways of providing water for a continuously growing population and hence a progressively less sustainable society. Let’s not get tricked into believing that we have to have this sort of continuous growth or that it will happen whether we like it or not. We CAN directly address it and curtail it if we collectively put our minds to it. And this factor is by far the most important aspect of this whole subject.

One of the most significant half-truths or pieces of misinformation is that we have to have continuous economic growth, and continuous population growth in order to achieve it

Ludvig, the reason the merits of water supply systems are being discussed here is that that is essentially what the thread is about - the myth of water scarcity. The thread is not about the sustainability of population growth. If that's to be discussed it should be in a different thread created for that purpose. The forum rules require that responses be on topic.

However, I am of the view that Sydney has already outgrown its water supply, and that steps need to be take to provide an adequate supply for the population Sydney currently has. Preventing further population growth in Sydney might ammeliorate the future water supply problems, but would do nothing to solve the problem we now have.

Sylvia

It was not clear just what the parameters of this discussion were intended to be. But I think the issues that I have raised well and truly fit in with the subject matter.

Sustainability is of direct relevance to the myth, or reality, of water scarcity. I do find it odd that you would suggest that it is not appropriate stuff to discuss here.

“Preventing further population growth in Sydney might ameliorate the future water supply problems, but would do nothing to solve the problem we now have.”

But it would most clearly work diametrically against ANY measures made to improve supply. So it is of direct relevance to the concepts of building desalination plants, more dams, installing tanks, mining groundwater, etc.

Thus, population stabilisation MUST be a part of any plan to improve water-provision. We simply MUST address the demand side of the equation as well as the supply side.

ludwig, you're absolutely right.
sylvia, the elimination of periodic flooding & sediment etc. only happens when you dam flowing streams. catchment dams on the other hand get filled with rainwater and can be placed anywhere. you could even have stormwater catchment which is far more easily and cost effective to filter than desalination. i personally prefer ludwig's approach. control (gawd i hate that word) of the population (humans AND animals) growth IS THE ONLY ALTERNATIVE period ! you simply can not have population growth without a growth in environmental problems. it just doesn't work that way. it's nature's law.

Reservoirs are not about catching water, they are about storing it. If you catch stormwater, you need to be able to store it somewhere. So if you want to use stormwater catchment, you need to determine the costs of either pumping the water into an existing reservoir (though new pieplies, and requiring lifting the water a considerable distance), or the cost of constructing new reservoirs and pumping the water into them.

In the latter case, you need data that lets your determine how much water needs to be stored to provide the required sustainable yield.

It's far from obvious that using storm water ends up cheaper than desalination. So if you want to claim that storm water catchment is the more economic, then produce some data and analysis that supports that view. Don't just state it.

So if you want to claim that storm water catchment is the more economic, then produce some data and analysis that supports that view. Don't just state it.

ok sylvia, we actually have and operate catchment lagoons for small communities. call them reservoirs if you like. the actual running costs come from the injection of small dosages of chlorine to control bacteria. low pressure pump running costs are insignificant. the desal plants are running 24/7. quite a difference in operational costs.
i can't see why many new residences couldn't have their own water supply. an outlandish idea ? well maybe, but consider this. the foundation of a residence could easily double as a reservoir. (ok some xtra cost) a 2 m deep reservoir of say 15 x 10 m would supply a family of 4 for 10 months @ 200litres per person/day and even longer with water saving devices. of course it wouldn't be logical for every house but if as many as possible have it then water supply would surely be less of a problem plus land requirements for storage would be greatly reduced.

Pragma,

How much does it cost to construct 2 m deep reservoir of say 15 x 10? That's 300 kilolitres, so it would have to be filled from storm water captured from a significant area - the house roof is not big enough. What is the cost of the pipework required to do that, the pumps, and the electricity cabling to power the pumps?

It's no good saying that it will supply a family of four for ten months. What happens afterwards, in a drought? Or to put it another way, what are the additional costs required to ensure that the water never runs out?

So far you're not providing costings, you're just offering points that you think represent an argument that it must be cheaper than desalination. If it is cheaper, then provide the analysis that proves it.

silvia, sure, building reservoirs would incur more expenses than not building any. but once built that's it. look at how much it cost to build warragamba and other dams. the running costs are a fraction in comparison. a huge desal plant however, would cost a fortune to construct and a fortune to run. can you imagine how much water rates would be if it had to be produced by machinery with ongoing costs ? that is a clear enough analysis. the average annual sydney rainfall is 1000mm. that's 150 kl for our house reservoir. it's also a hell of a lot of water that doesn't need to be supplied. of course larger buildings would yield more water. imagine all the grey water that could be stored for irrigation. the practical solutions are many. the problem with practical water solutions is that many consultants would miss out on syphoning the money reservoirs..
the real issue is not so much one of value for money. it's value vs money. the real value is in having an athmosphere and environment that won't need environmentally friendly power plants to make more athmosphere because we're ruining it by running power plants to make more water. that is also a clear analysis. if you really need a $ analysis then just get quotes.

Pragma,

We already know the cost impacts of a desalinator. The costings have been done, and Perth has almost finished building one. In Sydney, supplying *all* the water by desalination would cost about 50cents per kilolitre more than the current supply. In the face of that, hand waving arguments about capital and running costs are meaningless.

If your position is that storm water collection would be cheaper, then the onus is really on you to show that, and so far you've not done anything in that direction.

As for "silvia, sure, building reservoirs would incur more expenses than not building any. but once built that's it."

No, that's not it, by a long shot. Look at the thread entitled "The bane of my life: discounted cash flow."

Sylvia.

50 cents a kl is cheap. ours cost 5 cents a litre. what acreage will the proposed sydney plant require including the storage facilities. (i'll google the perth stats) with the many megalitre/day production what size are the proposed cleaning reject water reservoirs. how are they going to dispose of the water/chemical cocktail. with that kind of production i can't envisage evaporation being able to keep up with it. how are they going to prevent it from seeping into the aquifer. how will birdlife be prevented from consuming this water. what plans are there for the disposal of so many used membranes. can you recommend a www. site that has these explanations.
my concern is, how will we know when we reach critical point with overloading the environment with chemicals and emission. i doubt if nature will give us a sign along the lines of "ok people, you're getting close to to the limit, turn back now". it will be "sorry mankind, you've done your dash". science has provided us with many fantastic remedies so far but how many preventions can be listed.

It's not 50cents/kL, it's an additional 50 cents/kL on top of what the Sydney Catchment Authority gets paid for its water.

There's some discussion of the proposed Sydney desalinator here:

http://www.waterforlife.nsw.gov.au/__data/assets/pdf_file/1459/06mwp_chapter_7.pdf