While the 100 drops breakdown is interesting, it is marred by the last entry - "A massive 50 drops out of the 100 wastefully evaporate." This is emotive and ill considered language - if there wasn't evaporation there would be no 100 drops of rain to start off with.

Agreed Candide, my daughter is in the hands of the eco "aware" school teachers during the day - this morning I had to educate her about the water cycle. Might have a word to her teacher as well this afternoon.

Her fear today was that even though the drought is clearly broken in Victoria, she is still worried about water shortages and "wasting" water.

I told her water has to be returned to the cycle, to get rain happening - so excess water, going down the drain, is NOT a bad thing, it goes back to the cycle.

The hysteria and pandering to green/eco activists is putting the fear of the absurd into children's heads - heaven help the activists when the young work out what is going on with all the propaganda. They will turn on the green fascists.

On the article, yes, we should be building many more dams.

I'm afraid building more dams is not the answer. We have managed to stuff up the ecology of the rivers basins by building dams. Look at what is happening on the rivers like the Murray, Ganges, Indus and Mekong. We need to lighten up our footprint on the landscape and reduce the number of beings on the planet. The foolish and the ignorant out there keep throwing derision at Malthus, but as time passes, his ideas seem to be coming to fruition.

David

I read Peter Andrew's book Back from the Brink last year and then wrote several articles about it on my blog, using photographs of my land to illustrate his teachings.
Australian rivers were never intended to flow in deep gutters all the way to the sea, but to break over their banks and water the land.
Settlers tried to tame the rivers and channel the water, which suited people who wanted more fresh water down river.
Settlers tried to prevent floods, but only made the floods bigger down stream.

“This is emotive and ill considered language - if there wasn't evaporation there would be no 100 drops of rain to start off with.” Says Candide.
For Europe, rate of rainfall exceeds its rate of evaporation which is (very roughly) 650mm per year. For Australia, the rate of evaporation averages about 1,500mm per year for our agricultural areas.
On Candide’s thinking, we should be wondering why we are not receiving twice Europe’s rainfall; and why Lake Eyre’s annual rainfall is only about 12 centimetres rather than the 3 metres indicated by evaporation.
Duncan Brown (Feed or Feedback) writes of the perils for irrigated agriculture where evaporation is higher than precipitation. His logic, and that of the authors of this article, have quite a bit going for them in reasoning for the adaptation of agricultural practices to suit landscapes married to climate. The language of the authors, and that of Brown, is of reality - sobering, not emotional

vkwhatever .. "I'm afraid building more dams is not the answer."

really, what is the answer then to water storage?

"We have managed to stuff up the ecology of the rivers basins by building dams."

Are you saying the problems on the murray Darling system are not due to irrigation overuse, but to building dams?

Look at what is happening on the rivers like the Murray, Ganges, Indus and Mekong"

What is happening on those rivers?

Is it due to dams?

"reduce the number of beings on the planet"

Won't happen, so we will have to adapt - at some point it will become more important to survival of the species, than to worry about the indulgences of the eco/green types who have political motivation.

BTW - did you ever find those people who "deny that the climate changes"..? Not that anyone denies the causes, but you were adamant you could find evidence on OLO pages that people actually denied that the climate changes?

Psssst. Don't mention population.

If there were a price on water used for growing rice and cotton, would famers grow those crops, or would they use water more efficiently to produce more profitable crops?

Many farmers are to be applauded for improving the efficiency of water use but no one should be fooled into believing that there is no further room for improving the way in which water is used or stored.

The problem facing the Murray-Darling basin is not the use of dams to regulate the flow of water to the sea but the allocation of that water which exceeds available flow and for this reason is unsustainable.

The availability of that flow is of course dependent on how much it rains over the basins catchment area and of course the rate of evaporation, both of which are influenced by climate change.

Climate change is largely induced by human activity and is responsible for drier conditions becoming more prevalent over the southern half of Australia and for higher temperatures, the latter expected to increase evaporation of surface water.

Without international agreement among major greenhouse gas emitters to reduce their emissions and have those reductions policed, significant climate change will occur.

Action to limit evaporation and use water more efficiently is open to us and must be taken if Australia is to remain largely self-sufficient in food production and a net food exporter.

However, these are stop-gap measures which will not provide a long-term solution to the practices which are responsible for making them necessary, climate change which, if allowed to continue, will permanently reduce availability of water in the southern part of the continent.

"If there were a price on water used for growing rice and cotton, would famers grow those crops, or would they use water more efficiently to produce more profitable crops?" asks Agnostic.

The economically rational thing would be to grow less food and fibre - and more wine.

That would give fresh nuance to the claim that Australia is 'girt by sea and pissed by lunchtime...'

Agnostic of M, Water isn't free, it has a usage cost payable to govt, it has a pumping and distribution cost and it has an opportunity cost for those idle billions tied up in entitlements.

Water in cotton country regularly exceeds $250 per ML for temporary trade and did so recently. Much more than the $55 per ML in Murray.

Water is the key driver of my business and the best return using my allocation is to grow cotton. I could try growing vegies but would flood the market. I could irrigate wheat but would need to develop twice the acreage and get half the return.
Criticise allocations if you choose but to suggest farmers shouldn't grow the most productive crops they can, with the water to which they are entitled, is just poor thinking. Don't worry you're not alone, it's a common mistake.

JulianC, I hear a lot of grapes have gone unharvested in the last few years. Good return on the water there.

There is also a price on water for rice. And rice growers get the lowest security water, so it is only available to them in years when there is relatively more of it.

Highest security water apparently goes to orchardists, because you can't decide not to grow your peaches this year and do it next instead, as you can with grasses like rice.

I think the poor old rice growers get a bit of a bums rush in this as well.

I'm afraid building more dams is not the answer.
VK3AUU,
I think you're right on this. Evaporation, the influx of pest fauna due to more water, recreation and so on are some of the negative effects of dams. In my view recharging the groundwater is a far more sensible tactic.

The problem with growing cotton and rice, among the worlds thirstiest crops, is that except during times of drenching rains their production means that other users of water in the Murray Darling basin have to reduce their consumption.

We have all heard the complains of NSW and VIC irrigators that the water consumed by Queensland growers means less water river water for them. Using 1,000 gigalitres to grow rice during times of water scarcity has its effect on others.

Over-allocation and lack of balance between agriculture, urban populations and the environment, not just in Queensland or Victoria but throughout the basin are unsustainable, particularly when climate change produces drier conditions.

Business as usual is not an option. If it were, we would soon find ourselves with a river basin that was drying and dying and unable to provide irrigators or towns people with the water they need.

Water allocation reform, more efficient use of water, improved storage and tackling the problem of evaporation are all stop-gap measures which can and should be taken while we studiously ignore the root cause, global warming and its effects on our climate.

Agnostic, sorry old chum, the root cause is basically over allocation. This is compounded by other factors such as the inefficient use of the water, lack of recycling urban water supplies, the ever increasing need to grow food for an ever increasing population, the list goes on, but the basic problem is over allocation. If it's not there, you can't have it, end of story.

David

VK3AUU says … if its not there, you can’t have it
Quite right! But why is it not there?

Torrential rain this year and the drought is broken and very nice too. But the longer-term outlook is for drying of the southern part of Australia, based on predicted effects of global warming. And if that is not tackled it does not matter how well we reform allocations, use of water or limit its loss through evaporation. We need international cooperation on tackling global warming or else face the prospect of having insufficient water to allocate, use and conserve.

You won't get any disagreement with me there.

David

About 10% of runoff in the Northern cotton valleys will make it to the Murray mouth under natural conditions. Obviously none in a drought, but relatively constant in normal and big flows.

What this means is that a large amount of economic activity can happen without the severe evaporation and soakage losses along the way. Water purchased in the Gwydir Valley for $2400/ML last year by the govt equate to $24000 worth of Murray entitlement, and if you factor in our reliability at the average 40%(18% last 10 years)it would cost the govt the equivalent of $60000/ML of entitlement per reliable ML at the Coorong.

Starving water from the Northern Valleys is not the answer to the Murray irrigators. It's not economic and it's not a fair sharing of resource.

For a comparison of water consumption:
http://www.abs.gov.au/ausstats/abs@.nsf/0/E08CBF7F165B2CC3CA2574A50014D2F5?opendocument

I'm told the 6ML/hectare we apply to cotton is the same as people apply to their lawns. Evapotranspiration at work.

Graham has picked up on an important aspect that Rice growers only get to use water when there is abundant supply. We don't have a consistent supply in our country of feast and famine. Annual crops like cotton and rice respond quickly to avaialable supply. Oranges and almonds don't.

And so lies the "over-allocation" issue. Without entitlements in excess of average availability, big water years would not be able to average out the poor ones.

many of the technical issues can be addressed

evaporation on water storages can be dramatically reduced

at least 2 australian companies have products that reduce evaporation by at least 75%

however the fundamental driver of water shortages is population growth

the first law of sustainability (Dr. A Bartlett )

" Population growth and/ or growth in the rates of consumptionof resources cannot be sustained "

"17th law : If, for whatever reason, humans fail to stop population growth and growth in the rates of consumption of resources,Nature will stop these growths "

" 19th Law: Starving people don't care about sustainability."

" 21st Law: Extinction is forever."