Despite a billion of liters of annual rain, the equivalent of 2,000 Sydney Harbours, northern Australia has limited water, with 65 percent of rain lost through evaporation and 20 per cent in rivers, while only 15 per cent recharges groundwater reserves.
And climate change will make northern Australia hotter and drier by 2030, reducing water availability, said the report by the Northern Australian Land and Water Taskforce.
Northern Australia’s resources boom, with miners Rio Tinto and BHP Billiton fuelling China’s growth, is forecast to continue to grow significantly.
However, water scarcity in the north will be a major issue for future mining, along with access to skilled labor, said the report on sustainable development in northern Australia.
“Given the significant growth anticipated in this industry, it will be important to monitor the impact of the mining and resources industry on the water balance in northern Australia,” the government-commissioned report said.
Farmers and rural politicians have for decades called for the “Top End” of Australia to be developed into a food bowl, citing the success of the nation’s largest irrigation scheme, the Ord River Irrigation Scheme in the far northwest. The Ord scheme produces fresh fruit and vegetables, mainly for export to Asia.
“It will not be the food bowl for the world,” said Western Australian state politician Gary Gray after the reports release.
The report said: “Despite high rainfall from November to April there is almost no rain for the remaining six months.
“Evaporation and plant transpiration is so high throughout the year that, on average, for 10 months of the year there is very little water to be seen.”
Most rain falls near the coast or on floodplains, quickly running into the sea and making it hard to capture, and little in the upper reaches of rivers, where the topography is suits dams and water reservoirs. Few northern rivers flow all year.
The report ruled out more dams on environmental grounds and said the maximum area that could be irrigated from groundwater was 60,000 hectares, only three times the current area.
MINING, CATTLE TO GROW
Future agriculture in the north could expand by developing small-scale mosaic agriculture, however, and its cattle industry, which exports live cattle to Asia, could double in size by 2030 by intensifying production and improving feeding facilities.
Australia’s largest beef producer, Australian Agricultural Company Ltd, has major operations in northern Australia.
Northern Australia carries about 30 per cent of the country’s cattle and produces 80 per cent of live cattle exports, worth about up to A$400 million a year.
The gross value of agricultural production in the north by 2030 could increase by 40 per cent from 2000 levels in response to increasing demands for plant and animal protein from both Asia and domestic consumers, said the report.
Northern Australia is the center of the country’s mineral resources boom and will continue to grow, employing two-thirds of the region’s population by 2030, it said.
By 2030, the gross value of production (GVP) in northern Australia will be near A$35 billion, more than double the value in 2000. Mining, tourism, and marine and environmental service industries will account for 90 per cent of GVP, compared with approximately 60 per cent in 2000.