Australia & New Zealand: Water surpluses forecast for Warrego River QLD & Murray River NSW

December 1, 2016

The Big Picture
The 12-month composite map (below) indicates water deficits forecast in the southwest tip of Western Australia; coastal South Australia west of Spencer Gulf; along South Australia’s Limestone Coast; southeast of Melbourne; and western and southern Tasmania. Surpluses are forecast along the southern coast of Western Australia; east of Spencer Gulf; between the Lachlan and Murray Rivers in Queensland; and near Anatye, Northern Territory.

Impacts
Tensions are running high between Victoria and South Australia over water allocations in the Murray-Darling River Basin as the two states of Australia compete for limited water resources. The complex and evolving water licensing negotiations also draw New South Wales into the mix, along with federal, state, and basin authorities and representatives from the dairy and rice growers industries. The dairy industry in northern Victoria has experienced a 500 ML per year decline in milk production under the Murray Darling Basin Plan and farmers in the Goulburn Murray Irrigation District are using 60 per cent more water than they own.

After months of drought that left 80 percent of New Caledonia at heightened risk of fire and prompted a territory-wide fire ban, heavy rainfall in late November caused flooding and landslides that have killed at least 5 people, closed schools, and affected telecommunications, power, and drinking water supplies.

Forecast Breakdown
The 3-month composite (below) for the same 12-month period shows the evolving conditions in more detail.

The forecast for November through January shows the persistence of exceptional water surpluses in the Warrego River Catchment in Murweh, South West, Queensland; between Port Pirie and Adelaide in South Australia; between the Lachlan and Murray Rivers in New South Wales; and near Esperance along the southern coast of Western Australia. Moderate surpluses are forecast near Anatye, Northern Territory and south of the Murray River in Victoria. Mild surpluses are forecast to emerge during this period from King Sound in Western Australia to the western shore of the Gulf of Carpentaria. Moderate to extreme deficits are forecast south of Perth in the southwestern tip of Western Australia; along the Limestone Coast in South Australia; southeast of Melbourne; and North Island, New Zealand.

From February through April moderate deficits are forecast to emerge in Queensland, particularly across the north, and in western Tasmania. Moderate deficits will persist in North Island, New Zealand. Primarily moderate surpluses are forecast between the Lachlan and Murray Rivers, and moderate to exceptional surpluses are forecast to persist near Esperance along the southern coast of Western Australia.

The final months – May through July – show a forecast of abnormal (3 to 5 years) deficits persisting across much of Australia with moderate deficits across the north.

(It should be noted that forecast skill declines with longer lead times.)