continuation of preceding post...Thirdly, the toxins he fear, are already in the air we breath, and as we breath more air than drink water, he better start using an oxygen mask or spray painters mask! If you want to using rainwater for drinking, a simple filters and uv disinfection setup will do the job. Fourthly, re storage capacity. Congratulations (and commiserations) to his long suffering brother in law. No one expects rainwater harvesting to be the only source, and as all water customers pay their access charges for drinking water, they expect to use top ups. Its all a matter of space, tank size and demand. The value in rainwater harvesting, is that it complements other supplies and extends their security for those who don't have tanks (eg flats and tower blocks residents). Sydney for example has 1200mm rain per year, while Warragamba has 800mm. Hence the city's non-absorbent surfaces (roofs) not only have greater more to catch, but also deliver water more efficiently.

The disappointing side of the comments is that no one is willing to consider/discuss potable water recycling (40% of Singapore drinking water is created this way). Water recycling uses the same technology as desal, but with 1/3rd the energy AND also removes waste pollutants from our waterways and oceans, which currently pollute the environment (eg. plastic micropollutants). If people are sceptical about rainwater harvesting, no wonder the pollies use our "Yukfactor" reaction to encourage desalination of waste water recycling.

Allison Jane,
I am of the opinion that Australia has not come anywhere near requiring large scale desalination.
The amount of water provided by such desalination is already available a thousand times over. The problem is that the authorities acting on "experts' " advise are perpetually failing to use available water resources & so, the perpetual waste continues.
There is no need for desalination apart from island communities.
Dams, aquifers replenishing, soakage & storage of run-off etc cost a fraction & are a thousand times less polluting than desalination.
Govt should rid themselves of all the hangers-on "experts" & let people who know be in charge of such projects. We have had "experts" at the wheel for decades now & the proof is in the bag that they are the wrong people to make decisions !

Hi all,
HASBEEN - I love seeing a climate denier so used to saying "Don't tell me what I have to do with energy!" suddenly get up on his high horse and yell, "Let me tell you what YOU have to do for YOUR water supply!"

ALLISON - I understand there can be some bugs, but that I'm not that concerned about then precisely because of the fact that a/ we generally leave the bottom inch in a tank to create biota that clean up many of these bugs b/ we use water filters. I didn't think those water filters could deal with the various toxins, but if you have a scientific link that can show otherwise, I'm happy. I agree that breathing in nations that use fossil fuels isn't safe, and have often quoted how coal isn't cheap electricity because you pay for it again in the nation's health bill.

Also, if the WHOLE of Sydney is suffering the SAME drought (imagine that? Winks), then the WHOLE of Sydney's water tanks would be pretty much as empty as my brother in law's large round water tank. It's a drought. It means the water has stopped falling from the sky for everyone, not just me. Where's the water coming from?

Note: I'm not against water tanks but just don't have the money or space for large ones here. Maybe a smaller one in a few years.

INDIVIDUAL - Sydney's desal is running flat out yet our dam continues to go down. We have probably 500,000 to a million more people since the 1998 El Nino year drought. The VERY REAL climate science indicates it will start to become the new normal in just 20 years? Maybe you need to start hanging around some of these 'experts' you hate to learn just what a bad case of Dunning-Kruger's you already have.

Max Green,
I don't see any merit in arguing with someone who has an obvious financial interest in exploiting emergency situations. Desalination plants are quite a money maker because insipid bureaucrats invariably fall for wasteful industry rather than ensure value for money !
Build dams, not Desals ! Massive desals only add to the acidification of the oceans.
Use them only in REAL emergencies. I have long proposed for any new home to have its base built as its water supply. Sort of building atop a reservoir. Farms need to build more storage dams & soakage trenches. The main principle being to harness the run-off. Much can be done if only the "experts" are kept away because all they do is sacrifice efficiency for money.

Max Green... for the benefit of others who might fall for your bombastic commentary, here are the 7 stages used in producing good drinking water quality that exceeds drinking water standards.
1. first flush removal of heavy particles
2. course fiter of debris
3. sedimentation to bottom tank ( dead zone above offtake
4. Course 5 micron filter
5. Fine 2 micron filter
6. Activated carbon fiter to remove toxins
7. Disinfaection by UV lamp.

And if that's not good enough for you, then just buy bottled water... They uses RO filters just like a desal plant... that probably suites your taste more, despite costing 100's of times more than tap water and treated rainwater.. Even better the bottled water waste can generate even more plastic pollution and microplastic pollutants, unless you buy boutique glass bottled water imported from around the worlds virgin springs!

All right Allison,
I should have known better than try to ask for scientific evidence on OLO. I'm not saying it can't be done, but because YOU were being so bombastic and seemed to have so much evidence to hand, I thought YOU would be able to quickly link to an authority that would not only provide a quick summary of the science but the costs of various methods, etc.

There's a lot we could say about water efficiency in Israel, gradually adapting our city scape to store more water rather than watch it disappear down storm drains, capturing storm drain water, filtering river water for plastic before it goes out to sea, building more dams vs desal, etc. But the bottom line is while the average Israeli uses about a third less water than the average Sydneysider, they're approaching half desal and have goals of moving higher. And now they're EXPORTING WATER to surrounding desert nations!

If desal is so bad, why are they using it so much?

If Sydney ends up in a drought scenario like this more regularly, and this becomes the new norm with more years like this than less, maybe we need to adopt Israel's model and learn to "export" Warragamba dam over the mountains to the west where it can do some rural areas some good and have Sydney go 100% desal!