It seems the only place it rains here in Australia is the tropical North, where every summer the heavens gush forth an orgy of life-giving water which flows right out to sea. The rest of the continent is left to suffer the usual water deprivation. Sheep, centuries-old gumtrees and fruit trees wither and die.
Now every time there is a prolonged drought here in Australia, laymen, visionaries and other fools begin once more to talk of pipelines from the north.
Talk of such megaprojects to supply the arid south with abundant water from the continent’s tropical north have been around for about a century. Cost analyses have been done several times in the last century, and have always found that the project is infeasible. To bring the topic up at a dinner party is to invite ridicule. It seems that firehosing ambitious infrastructure projects is everyone’s favourite sport.
Here in South Australia, the Morgan-Whyalla pipeline was completed in 1944 to supply Murray water to the steel city on the Spencer Gulf. The Mannum-Adelaide pipeline was completed in 1955 to conduct drinking water to Adelaide. Today both pipelines remain essential to the economic viability of South Australia. Each is only several hundred kilometers long.
The Olympic Dam expansion in the state’s north will require huge additional water resources. These will not be met by aquifer extraction alone. A desalination plant at Port Augusta is planned, and a pipeline from there to the mine site some 400km to the north. One private company, (ok, Australia’s largest) will foot the entire bill.
When talk turns to building a pipeline 10 times that long from say from Lake Argyle to the Riverland, we might expect the cost to be 10 time greater. Detractors say that the cost of shipping water in tankers from the Derwent River in Tasmania, would be more economical. A pipeline, while attractive to simpletons, would be a white elephant of huge dimensions, a political folly certain to sweep you from public office for two terms at least. That is the state of the debate at the moment.
Well I would actually like to know the technical details of any cost analysis which has been performed! In particular, what proportion of the overall cost is attributable to pumping alone. The capital outlay of pumps every say 50 kilometers, supplied by high voltage overland power lines, step-down transformers, monitoring equipment etc. etc. I am thinking a megawatt pump every 50km at least. I might attempt the calculations myself bit later but for now I am going to guess that the electricity costs are about half of the ongoing cost of each liter of water.
Has anyone ever been even a little bit creative in designing a pumping solution? Something which requires a lateral approach? Where, say, the energy for the pumping is collected locally and does not have to be shipped in? Anything spring to mind? As you might have guessed, I am talking about the sun. Moreover how about a solution where electricity is not even involved? Why turn the sun’s heat into kinetic energy, to turn it into electricity for the sole purpose of turning it into kinetic energy again??? Seem wasteful to you? Me too.
OK so alert the CSIRO because here is my preferred system design for the pumping station:
Use an Ausra compact linear fresnel mirror array to generate high pressure steam and push the water down the pipe that way.
The technical equivalent of a 19th century steam train, powered by the sun, will pump the water using a piston pump. Sounds pretty compelling if you ask me. Yes I do realise that steam turbines are more efficient. However system reliability and lifetime cost are almost certainly lower with a primitive steam pump.
There are practical hurdles, naturally. Flow at night would be zero. Then again so would energy costs. On any given day, not all pumping stations will be receiving equal amounts of solar heat. The flow would be limited to the flow of the least performant station. However the canal presents such a large buffer, that these fluctuations will be smoothed out over the course of the canal, as long each pump is sized according to local insolation levels.
It has been suggested to me that the 21st century Dutch are presently removing water from their water-logged agricultural land using steam-driven pumps, and have been doing so for over a century.
So on to the calculations:
Let’s use a pipe with a 60cm diameter. Assume water is flowing on average at 5m/s. The flow rate over 24 hours would thus be around 324ML. This is far more than the capacity with the new Kwinana desalination plant in WA, which produces about 140ML a day. Assuming 6 months of daylight for 12 hours a day, and 6 months of 8 hours, gives a total annual carrying capacity of about 49GL in round figures.
(Note: If we implement pressure storage at each pump and use it to achieve full 24 hour operation, the annual carrying capacity becomes 116GL.)
You would need a mere 80 pumping stations. Suppose they cost AUD $10m each in round figures. That’s $800m.
Add the cost of concrete pipe construction. Each 10m section of pipe is around 2 cu.m. of concrete thus around $180 in concrete alone. You need about 400,000 of these. This would be a mere $72m in concrete.
You might fit ten sections on each railway carriage. Transporting it to the dropoff point perhaps $2000 per carriage. That means train haulage of 40,000 carriages or $80m.
The pipeline is 4000km long. Let’s assume the Adelaide-Darwin railway is usually no more than 500km from the pipeline. So on average the sections would be trucked 250km to the assembly area. This would be over inhospitable terrain. This time assume 5 sections per truck, at $2000 per delivery, or $160m for all the pipe.
Earthmoving for site preparation perhaps $1m per km although I have pulled this out of my hat. A further $4bn.
Total project cost: Around $5.1bn. At 12% return the financing costs are around $613m per annum.
Assume maintenance and running cost of the pumping stations to be 3% of the capital costs, or $24m p.a.
Thus the financing charges are $637m p.a.
Is this a worthwhile investment? How do we quantify the benefit, and convert that into some measure of revenue? What options are open to us? Sell the water by the megaliter to the highest bidder? That would assume that the water pricing model currently in place assigns a true value to each megaliter. On the evidence, it is reasonable to think that it does not. What about the expected increase in GDP? The expected economic multiplier effect? Arguments will rage on and on about which methodology is correct. To me, intuitively, and using my own unique biases and value judgements, I am perfectly content to assert that delivery of 49GL a year to the Riverland is worth $637 million a year. That is because the effect on the entire region would be transformational. But if we had to invent some quantitative BS then that is a whole lot more work – but it could be done.
How might we do it: there are a number of ways. First, looking at it from the perspective of security of supply. We might calculate the economic cost of a decrease in supply to the Riverland, of that amount of water. This might be in the billions. It is a lot of work to calculate but it could be done. Let’s estimate that cost as $5bn. Now the likelihood of this is say 0.5% in any given year. Thus we should calculate the benefits of supply security to be $25m.
Next, we might calculate the benefit of additional environmental flows in the Murray. The benefit to tourism might be of the order of $100m to the local communities.
Let’s say that this means no more Murray water needs to be pumped to Adelaide. The cost reduction in pipeline and treatment operations might also be of the order of $20m per annum.
Trying to quantify the benefit to the local communities by better access to drinking water is fraught with difficulties. Initially you might think that the only benefit is if either the cost of the water is reduced, or the quality is improved. Quality might well be improved but let’s not dwell on that. Cost might actually go up if the water is funded with a user-pays system. The availability of water itself, is the one thing which gives the greatest benefit
Now the increase in agricultural output should be the largest single benefit of doing this pipeline. It is also the hardest to quantify.
The one way is to look at the economic cost of a given reduction in water allocations. This has surely been done already. Let’s say it is $10,000 per ML of water per year – a very low figure. It is probably way higher but let’s be pessimistic for now. This cost is through reduced farm and orchard output and decreased livelihood in the rural community.
So this means that an increase of availability of water should be worth $10,000 per ML of water, irrespective of the price of the water. That is not to say that each ML should cost $10,000, just that this is what it is worth in terms of it being a critical resource which enables $10,000 of “livelihood” to be earned.
That said, supply of 49GL per year to the Riverland, should be worth $4.9bn in additional production per annum. Now certainly the production is not linear. After a certain point, not every ML is worth an additional $10,000. The value calculation only applies to the extent that water is the constraint – i.e. the critical resource.
