Monday, December 1, 2008

Water, water everywhere, but never a drop to drink

We've finished with psychology and we're back to politics. Ladies and gentlemen, this song is called Rattler, or, how a high school dropout with water on the brain can out-think the best political brain in Spring Street.

In case any of you don't believe me, yes, I did drop out of high school after about Grade 14. It was university level education by Australian education standards but we homeschoolers call it high school because we have high expectations. As for the water on the brain - that's metaphorical, not physical. I've had a fascination with dihydrogen monoxide since the age of four.

Now as we all know, Mr Brumby has achieved quite an amount of publicity for his proposed solutions for Melbourne's coming water crisis. All publicity is good publicity isn't it mon Premier? Ah well, better luck next time.

The letters sections of the newspapers are ringing to the sound of people offering solutions - and the criticisms of the solutions offered. Great fun reading.

Let's go back a few steps and look at the situation in detail.

Back in the 70s the Cardinia reservoir was built, and the government of the day promised that Melbourne would never need to have water restrictions again. That idea lasted until very recently (30 years, not bad for a political promise!).

So suddenly water becomes a hot topic (no puns please) and the government Must Do Something About It.

I know, says Mr Brumby, the Goulburn is in flood this week, let's build a pipe to take all that water away from where it's doing damage to where it can be useful! Brilliant thinking sir, but did you know floods recede in less time than it takes to build a pipe?

Well just in case the pipe construction takes longer than we expected, we'll have a desalination plant too. Oh hang on, that takes lots of power. Well we'll bury the carbon!

Talk about thinking aloud without worrying about whether it's a good plan or not...

Let's all go back to primary school. Australia is a dry continent, right? And that's because it gets really hot, right? And because it's hot the water dries up and we need more of it. So let's spend lots of energy heating water to purify it, then cooling it and using it to replace the water the heat dried up.

Anyone else seeing a really big short cut we could take here?

OK, enough politics, down to a bit of just plain water. Here's my ideas for making sure there's plenty of water for the extra million people whose taxes are going to pay for public transport improvements in the next ten years.

1. Wider use of grey water
Grey water can include just about anything - stormwater mixed with leaves and dust from the drains, household waste water (excluding the really nasty stuff - that can still be sewage), water from rivers deemed not clean enough for drinking, etc.

What we can use grey water for is just about anything that doesn't involve human or animal consumption. How many industries need water for cooling? It doesn't have to be guaranteed free from bacteria, it just has to have a high latent heat of vaporisation. And even in the household every toilet flush, every car wash, every floor mop can be done in grey.

For the same cost as a north-south pipeline, how many residential areas could be fitted with grey water pipes? And which would be better for the water supply, really?

2. No half-measures with pipes!
Our good friend in Darwin constantly reminds us that the rain in the wet season is infallible, the lawn grows so fast he has to hose the clippings off his driveway after mowing, and by the time he finishes it's time to mow again. And while we're moving onto Stage 3a water restrictions here there are floods in Queensland and northern NSW.

So let's have a massive network of pipes - not for constant flow like the north-south is supposed to be, but just enough to balance water needs with water supplies. And of course we have a wonderful river system - all we have to do is pump water up to the source of the rivers and let it flow down hill to where it's needed. Hey presto, we have water in the river to keep the lesser carnivorous polkadot bellied Murray trout population alive, AND we can pump the water off in the population areas and drink it (or wash our cars in it)! Two for the price of one!

3. Catch that great steaming monster before it flies away!
Evaporative cooling is quite efficient in terms of energy consumption and mechanical simplicity - but of course it uses water. But it doesn't really "use up" the water - it will be back again, as rain - somewhere.

So why not capture it? Build a nice long steam pipe heading down to an underground condensation tank with a Stirling Engine to pump the steam down and the water up. Free water. Probably drinking quality.

4. Don't be ridiculous
Sorry to have to say it, but rice (for instance), which needs to be grown in a paddy field, is not exactly a suitable crop for the Echuca area. Not without a lot of irrigation anyway. Until we have that network of pipes and a plentiful supply of tropical rainwater, we should be importing our rice. Swap you for some wheat? It's more suited for our climate.

5. Make it rain!
If you get out of your warm bed on a winter morning and go to some of our fringe suburbs where open paddocks, apple orchards and medium density industrial estates share a square mile block (a dying breed I'll admit) you can see that the fog forms on the open ground. Thus, a large body of plant matter will partially sustain itself, by attracting precipitation.

Of course it has to be a large body of greenery to achieve critical mass, but that sort of thing should be possible to organize.

The other thing is to make sure the water doesn't blow away. Open paddocks big enough to swing a combine harvester probably won't hold much. Stick a few lines of trees in to break the wind and watch the grass grow.

6. Free desal!
Roll up, roll up! Yes folks it's absolutely FREE! Just warm your seawater in the heat of the sun and condense the vapours and it's yours gratis and for nothing!

I touched on this above. Why spend energy heating water to purify it so it can be used to replace the water lost to heat? We should be using some of our excess square kilometerage for a sort of greenhouse setup, which can have seawater or bore water introduced, heated in the sun and the vapour captured to make drinkable water.

There was an experimental setup in Queensland which did exactly that, and had a fairly ingenious safety cutout so that it would never let unfiltered water through - if anything went wrong it would fail safe and shut itself down completely. It was even designed to be isolated from maintenance for years on end.

So there you have it. Plenty of ways to manage our water crisis without spending heaps of energy, or robbing Peter to pay Paul, or leaving the fish out to dry. Can I be a consultant and earn a six figure salary now?

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