Andrew Campbell, director of the Research Institute for the Environment and Livelihoods (RIEL) at Charles Darwin University, writes: Here we go again.

The Coalition proposal to dam rivers in northern Australia to create a massive food bowl has been floated before, as have various schemes for harvesting water from what is perceived to be the over-watered and under-populated north and redirecting it to the under-watered and populated southern regions of the country.

Both of these ideas are superficially attractive, especially when you sit in an office in water-restricted Canberra, Sydney, Melbourne, Adelaide or Perth, look at a map of Australia and see that 60% of the continent’s runoff is in the north.

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Yet neither of them withstands any serious economic analysis, which may be why private investment in such schemes has been so modest and ephemeral.

Before any new dams in the north are proposed, it is crucial to understand the lessons from the Ord River. Public investment in Ord Stage One from 1958-91 incurred a net loss of $511m (1991 dollars) against a net private benefit of $14m, and only 4,400 hectares of a potential 70,000 hectares was being cropped at that stage.

This unviability had been predicted by the economist Bruce Davidson in 1965 in his seminal (and much ignored) book The northern myth: A study of the physical and economic limits to agricultural and pastoral development in tropical Australia. In the twenty years since, the area under crop has grown to more than 15,000 hectars and the gross value of agricultural production to around $100m.

Salinity problems had already emerged by the early 2000s. Taxpayers are continuing to underwrite the expansion of the scheme: the WA Government is investing $220m and the Commonwealth $195m in Ord Stage Two, but the level of private investment is uncertain and no serious economic analysis has been done.

If and when the Ord Irrigation District is in the black — let alone consistent with COAG water reform principles that water pricing should reflect the full cost of infrastructure provision and maintenance — we may be able to apply the lessons learned to other tropical schemes.

Joe Ross, Chair of the Northern Australia Land and Water Task Force, observes that most of the value currently being generated from the Ord today is from sandalwood, not food crops. “Now, you tell me, can you eat a bowl of sandalwood?” asked Ross.

That Task Force, which delivered its final report in 2009, was the latest of many studies since 1912 to document the formidable constraints in northern Australia to conventional notions of irrigated agriculture — whereby you dam a river, to supply a large contiguous irrigation district downstream of the dam.

Firstly, for sustainable food production at any scale, reliable water supply is essential but not sufficient — you also need good fertile soils. The soils of northern Australia have been leached by monsoonal rains over thousands of years. They are low in nutrients and organic matter, they can’t hold much water, they erode easily, and they have low infiltration rates. These traits, combined with the very high amounts of solar radiation and evaporation rates of the north, mean that crops have low water use efficiency and evaporative losses from dams are extreme.

Prospective dam sites are limited, and tend not to be located near reasonable areas of arable soils. A megalitre of water weighs one thousand tonnes, so moving it any distance over flat lands requires lots of energy, which is why the calls to pipe or channel or carry water from the north to the south are so misconceived, failing the most basic tests of physics or economics.

Extreme monsoonal rainfall events are problematic for large-scale irrigation systems. Input costs — fertiliser, chemicals, diesel — are much higher in the north, as is the cost of getting produce to market. Labour costs also tend to be higher, and it is difficult to attract skilled workers to live remotely in difficult climatic conditions, especially in competition with the wages offered by the minerals sector.

I am concerned here primarily with physical and economic arguments, but suffice to say that the environmental, social and cultural impacts of a network of dams and irrigation schemes across one of the largest regions of free-flowing rivers left in the world, would be profound.

My colleague Professor Michael Douglas has noted the crucial connections between Wet Season flows and coastal fish stocks. Many tropical fish species need to move between salt water and fresh water to complete their life cycles, so the connectivity of these monsoonal systems, both between upper catchments and the coast, and between rivers and floodplains, is crucial for recreational, commercial and indigenous fishers.

The Northern Australian Irrigation Futures research project (2003-2007), led by CSIRO, examined what sustainable irrigation systems in northern Australia might look like.  That project concluded that a patchwork mosaic of smaller-scale irrigation based on groundwater, located in areas with better soils and better transport options, possibly integrated with the pastoral industry for fattening cattle and other livestock options, would be more prospective than large dams.  But this concept has yet to be tested at any significant scale in the north, nor subject to economic analysis.

The Australian editorial of September , while critiquing what it called “the dam buster mentality” concluded with a sensible caution to “avoid projects that are not viable, either economically or environmentally.”  Proponents of large-scale, conventional irrigation schemes based on dams in the north need to be able to disprove Davidson. No-one has yet done so.

Yet for all the reservations about dam-based irrigation schemes, there is something inherently tantalising about the idea of big, nation-building projects in the north.

As a recent refugee from southern Australia, I think that we should envisage Darwin not as the marginal northern outpost of a continent of 22 million people, characterised by NT News croc stories, but as a richly-endowed, southern centre of expertise and sustainable development know-how for the 500 million people to our immediate north.

Concerns about food security are entirely valid. We should be thinking strategically about how Australia can best contribute to meeting the challenges outlined by Julian Cribb in his latest book The Coming Famine. The world needs to increase food production by about 70% by 2050, using land, water, energy and nutrients much more productively than we do now. This is a formidable technical challenge.

In my opinion, we would get a much better return for the taxpayer from greatly increasing our investment in agricultural research and extension, both here in Australia and particularly in the countries to our north, to help them increase their own agricultural productivity. For example, only 45 minutes by air from Darwin, we have a million neighbours in Timor-Leste with high levels of malnutrition, infant mortality and seasonal hunger — yet with huge possibilities to increase their own food production, both on-farm and in value-added processing and distribution facilities, given appropriate advice and support.

Australia has a comparative advantage in agricultural research and extension, especially in variable climates, poor soils and energy-efficient systems. We can generate significant export earnings and international goodwill from our agricultural know-how. Helping other countries to develop better farming systems, forestry and fisheries to feed and shelter their own people is likely to be a better return on Australian taxpayers’ funds than damming our own northern rivers and repeating the mistakes of the past and the south.

There are strategic imperatives to develop the north, but in my view an export-oriented, conventionally-irrigated food bowl is not the answer.

If the Coalition or the Government are looking for nation-building schemes that will deliver sustainable jobs and economic development in the north, and will help position the Australian economy for the 21st century, here are some possibilities.

Why not consider large-scale exploitation and export of the vast renewable energy resources of central and northern Australia? The German government plans to decommission nuclear power stations, and is considering import of renewable energy from large-scale solar facilities in North Africa. The Norwegians and the Dutch have recently linked their energy grids through a high-voltage, direct-current (HVDC) undersea cable called NorNed. Similarly, we could link up the massive geothermal, solar and tidal resources of northern Australia for export to the region. An HVDC cable from say Katherine to Kuala Lumpur, via Darwin, Dili, Jakarta and Singapore could service energy grids supplying several hundred million people.

We currently have large-scale resource development projects worth hundreds of billions underway or planned here in Australia. These are depletable natural resources that we can only dig up and sell once. We have the technology and the capacity to ensure that all minerals and fossil-fuel energy projects are carbon-neutral, directing major offsets funding to create a sustainably managed carbon bank and ‘on country’ jobs for indigenous people from the Kimberley to Cape York.

We do need to increase food production in the north, at least to the point of self-sufficiency for growing populations, and to improve resilience in the face of rising energy prices, extreme weather events and long vulnerable supply chains. But we can do that through substantially increasing local food production through small-scale, high-tech, irrigated horticulture based on sustainable use of groundwater, stormwater and urban wastewater.

These three proposals, if well planned and managed, would complement and add value to the tourism industry, and build capabilities that will be needed throughout the world this century, while benefiting rather than compromising the extraordinary natural and cultural heritage of northern Australia.

CSIRO scientist Dr Garry Cook, in his fascinating historical chapter in the Northern Australia Land and Water Task Force science review, notes that the recurrent calls for the agricultural development of the north invariably come from southern Australia, and are driven by pressures external to the region.

The very establishment of the Northern Territory through the federal takeover of the Territory in 1911 was driven in part by the slow progress of agricultural development. The first Federal Parliamentary Inquiry into this issue toured the north in 1912. There have been many inquiries and studies since, and there is a consistent thread to their findings. It would be prudent to heed them.

The convergence of food security, energy security and water security concerns does indeed present challenges for northern Australia, as it does elsewhere. We need to be thinking about these issues in a more integrated, joined-up way, and looking for solutions that position us for the world we are moving into, not those imported from southern Australia, that have failed in the past.