Irrigation schemes in Australia

Irrigation is vital in Australia; it’s the only way we can produce a lot of our food, due to our naturally erratic rainfall. And in dry years, it’s the only way a lot of livestock can be kept alive, or fattened.

Atherton Tablelands farms close to Tinaroo Dam, on the Barron River. A huge variety of high-value crops are grown in this rich volcanic soil – the most versatile farming region of Australia.  Yet there is still a great deal of development potential.

But it’s very frustrating to hear politicians and others yet again spruiking the idea of taking a huge amount of water from North Queensland rivers & transporting it a long distance to more arid inland regions.

Because:

  • Yes a huge amount of water flows down tropical rivers and out to sea each wet season. But the environment is adapted to that – IE the health of these rivers, and the sea life near the mouth, depends on it.  A vast array of native species depend on this annual influx of fresh water and nutrients, some of which form a valuable fishing industry (particularly prawns and barramundi). Harvesting water during the wettest years and storing it in deep dams (less evaporation) makes sense. But tropical wet seasons fluctuate and in drier wet seasons, little or no outflow could or should be stored.
  • Northern/inland Australia has huge evaporation rates even in the most amenable years – well over 2 metres annually, which is well over the annual rainfall.  Sending water long distances south or west via man-made open channels or by sending it overland into rivers in other watersheds, would see massive water losses due to seepage and evaporation. And pumping would be financially out of the question.  Efficient? Exceedingly not.
  • Has anyone asked North Queenslanders if they’re happy for their regions water to be given away and shipped south?  If northern inland Australians wanted to take water from one of Victoria’s largest rivers and pipe it hundreds of km north, would there be an outcry? (Oh wait – Victoria doesn’t have any really large rivers. Instead they’re tapping into the Murray system, via the Goulburn. How that was ever permitted, not that long ago – piping over the Great Dividing Range into a completely different catchment and just for urban use – I don’t know. Would Melbourne donate water to Mildura to grow food? Hell no!  Australia’s northern assets are apparently ripe for the picking by southern Australia, but the reverse never applies.)
  • Cropping requires a substantial investment in fencing, drainage layout for flood irrigation or costly spray or piping systems. And expensive planting & harvesting equipment. And a skilled workforce. Plus other infrastructure, from on-farm sheds and grain storage to efficient transport systems. Millions invested in capital and labour needs to earn it’s keep most years or farming is not economically viable in this day and age; especially when more distant from major population centres and ports (IE the higher input & transport costs that northern & inland Australian agribusinesses have to survive).  This huge capital investment is something that most in the northern cattle industry are not au fait with. Farming, especially irrigated farming, is a whole world away from operating cattle stations.  Anyone who needs a lesson on the unviability of irregular/unreliable irrigation water supply – head to the dairying country in northern Victoria, fruit growing around Mildura, plus the NSW towns of Griffith, Finley, Deniliquin and other irrigation towns – and talk to local farmers. (Irrigation water either unavailable or not available at an economic cost; a problem exacerbated in recent years by the flourishing industry of water-trading – which includes people who’ve never set foot on a farm.)
  • There are already 3 large irrigation areas in northern Australia that are operating well under capacity/not fully developed (in terms of ROI; value of crops grown etc): North Queensland’s Burdekin irrigation district, supplied by the Burdekin Dam; Far North Queensland’s Atherton Tableland supplied by Tinaroo dam on the Barron River; and Western Australia’s Ord River region (in the East Kimberley), supplied by Lake Argyle. Why have these areas not already been developed to maximum capacity? Economics (higher input costs, long distances to markets, plus more challenging wildlife and pest/disease problems inherent in tropical agricultural regions worldwide). So it does not make sense to spend hundreds of millions on developing another irrigation scheme in northern Australia – a far more expensive one – before the full potential of these 3 existing irrigation areas is fully realised. Particularly considering all three of these areas have a higher/more reliable annual rainfall and relatively fertile soil; compared to the region where this new irrigation scheme is proposed for.
  • This latest scheme may well appeal to the locals in the immediate vicinity who are overly optimistic re outcomes and envisage $ rolling in, either via increased land values so they can sell up and profit, revival of rural towns (including saving small town businesses), or so they can morph from livestock producers into farmers – but it won’t stack up on economic grounds.
  • Every single person I’ve seen commenting in favour of the latest proposal, doesn’t have farming/irrigation experience. It’s being seized upon in desperation to cure big problems and relieve business and community suffering. I really wish it was a cure as what many regional Australians in drought-stricken areas are going through is horrendous (landowners as well as small business owners and residents in small towns). But unfortunately this irrigation scheme is not the answer and fostering unrealistic expectations is detrimental rather than helpful.

The Burdekin Dam spillway, which was originally designed to be raised and a hydro electricity generating plant added. Burdekin irrigation water has been traditionally used to grow sugar cane but it now grows an increasing variety of high-value crops. It is also a back-up water supply for Australia’s largest city north of Brisbane – Townsville.

Where to from here, for irrigation in northern Australia?

  • Anyone who wants to give northern irrigation a crack should head to existing schemes in the Burdekin, Atherton Tableland or Ord region.  Move people north, not water south, and make full use of what we already have, in areas of more fertile soil and rainfall that is higher and/or more reliable.
  • When the irrigation schemes on the Ord, Burdekin and Barron Rivers have reached capacity and are operating profitably and sustainably, then let’s talk about the options for expanding irrigation into new areas of northern Australia. Undoubtedly as the population in northern Australia grows, other schemes may well be feasible in future. Especially if Melbourne, Sydney and Brisbane sprawl continues unchecked, cementing over what is some of the most valuable food-producing land in Australia.

Burdekin River in full flood (the road is underwater, marked by the ripples). Many unfortunately see floods such as this as ‘wasted water’ but in fact floods are required to de-silt northern rivers – cleaning out built-up sand and debris deposited during average wet seasons.  The Burdekin dam holds 1,860,000 megalitres and is located downstream from this crossing, between Townsville and Charters Towers.

What do I base my irrigation observations on?

  • I grew up on an irrigation farm which was developed in the 1950s and have seen the economic and environmental challenges first hand across a range of irrigation areas.
  • I’ve lived in 3 eastern states – including on irrigation farms – and visited every state for agriculture-related work over 35 years.
  • My view is independent as I have nothing to gain either way – unlike politicians seeking election, farmers seeking security and other businesses seeking to profit.

Lake Argyle, on the East Kimberley’s magnificent Ord River. Australia’s largest irrigation dam and the fastest-filling dam in Australia, due to the rocky hills surrounding it. (The largest dam in Australia is the Gordon, in Tasmania – built for hydro power generation.)

We need more water storage. It’s a no-brainer that the Burdekin Dam wall should be added to (raised), as originally intended when it was designed, and a decent-sized hydro electric power system built. What we don’t need is vote-grabbing, hair brained new water movement schemes – based on bodgy premises and which will just soak up millions in consultant study fees and drag on for years with no results.

We must instead make full use of what we already have. And – stop our capital cities expanding onto our best food-producing land.

Lastly  – don’t get me started on irrigation from the Great Artesian Basin or uncapped artesian bores! It is insanity to permit a select few to take water from a vast aquifer that so many livestock producers and inland towns absolutely depend on, yet we still know so little about. Controlled extractions of livestock & household water from the Great Artesian Basin – absolutely yes. Spray irrigation in arid areas? Large amounts used for mining activity? Not until we know a lot more about the Great Artesian Basin – exactly where the water comes from, how old the water is/how long it takes to replenish, et cetera. (Note that the vastness of the Great Artesian Basin makes it quite different to smaller aquifers, which are more easily studied and can be monitored a lot more accurately – but which must still be regulated. Water belongs to everyone, not just a handful of individuals out of the many who live above certain aquifers.  Years ago Yabulu Nickel Refinery was gifted access to the aquifer north of Townsville & local residents prevented from sinking household bores. That kind of iniquitous situation must be rectified & fairness applied.)

I’m all for visionary capital works in northern Australia. But the ‘New Bradfield Scheme’ – which includes taking water from Far North Queensland’s Tully River and delivering it to the Murray-Darling via the Warrego River, which ends up entering the sea near Adelaide – is beyond the pale nonsensical, from every angle.

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