Four potential dam sites in far-north Queensland: CSIRO report

CSIRO lead researcher Chris Chilcott said despite the abundance of rain, the rivers in northern Australia weren't very big, with the major of their flow occurring over a short period of time in the wet season.

"Our goal was to look at what the soil and water resources were in these catchments, identify ways you can catch that water and store it, and look how it was commercially viable to support agriculture," Dr Chilcott said.

"Then we assessed what the potential environmental, social and economic impacts would be if you undertook some of those developments."

In far-north Queensland, the study focused on the Mitchell catchment, where four major cost-effective dams were identified - the Rookwood, Palmer, Nullinga and Chillagoe dams.

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"These four are the cheapest ones and the ones that support the most water," Dr Chilcott said.

"They would cost about $3 billion [in total] to build. So they'd be significant investments, but they would be quite viable."

The dams could deliver about 2800 gigalitres in 85 per cent of years, which is enough water to irrigate 140,000 hectares of sugarcane.

That would generate $720 million in gross production value, $1.5 billion in annual regional economic activity and create about 7250 jobs.

In Western Australia, the Northern Australia Water Resource Assessment focused on the Fitzroy catchment.

"For the Fitzroy we didn't look at on stream storage," Dr Chilcott said.

"There's been a long-standing somewhat bipartisan approach to that, saying they didn't want large dams."

The study found that water harvesting could support about 160,000 hectares of irrigation at a reliability of 85 per cent, while groundwater could support about 30,000 hectares.,

"It could be highly profitable in some situations, because it could be part of a beef enterprise and the ground water is artesian, so there's very low pumping costs in that as well," Dr Chilcott said.

"So more than likely, the approach taken will be around these are low-risk low-cost approaches to supplement the existing agricultural system, which is cattle, with things like centre pivots."

The report also found opportunities in aquaculture, such as prawns and barramundi, with about 55,000 hectares of land suitable for lined ponds.

University of Queensland chancellor and former secretary of the Department of Foreign Affairs and Trade, Peter Varghese, said the nation should "think big" about agriculture in northern Australia.

"If you look at the supply and demand outlook for Asia - even if the region has slow growth - the numbers are very good for Australia," Mr Varghese said.

"We are remarkably well placed to service that market and northern Australia is an obvious choice of places to work in to take advantage of that.

However, developing the region "is not going to be straightforward and it will be expensive". He doesn't see it happening without government investment.

"If you want to increase agricultural production, the north can offer large opportunities, but you will need very considerable investment and not all of it is going to come from the private sector," Mr Varghese said.

"I think we will need to see significant government funding but I don't think there is much appetite for this at the moment.

"We seem to have a northern Australia strategy but still no resources behind it."