Australia & New Zealand: Intense water deficits persist in Tasmania & New Caledonia

28 February 2018

THE BIG PICTURE
The 12-month forecast (below) continues to show exceptional water deficits in Tasmania and along Australia’s southern coast from Adelaide to Melbourne. Moderate to exceptional deficits lead from Adelaide north, spanning the border of South Australia and New South Wales. Intense deficits are forecast for much of central Queensland to the Gulf of Carpentaria.

A wide path of moderate deficits splits the country down the middle, leading to slightly more severe deficits in Northern Territory’s Top End surrounding Darwin. Severe deficits are expected to persist in the southwest tip of Western Australia near Busselton. Farther north in WA’s Kimberley region surpluses are forecast. Some moderate deficits are forecast along eastern Australia from Canberra to Brisbane, and surpluses are forecast west of Bundaberg, Queensland.

Deficits of varying severity are expected in pockets of New Zealand and moderate deficits are forecast for New Caledonia.

FORECAST BREAKDOWN
The 3-month maps (below) for the same 12-month period show the evolving conditions.

Widespread, exceptional deficits observed in recent months in Australia are forecast to nearly disappear. However, severe to exceptional deficits are expected to persist in Tasmania, particularly in the west, and near Busselton, WA through April, downgrading thereafter. The forecast through April indicates primarily moderate deficits from the Eyre Peninsula in South Australia through much of Victoria and into New South Wales. Some severe deficits are forecast for parts of Riverina, NSW. Moderate deficits are forecast for central Queensland to the Gulf of Carpentaria, and stretching northwest to Darwin, where deficits may be more severe. Deficits are expected to retreat significantly in New Zealand, though pockets of intense deficits will continue to emerge in the south and moderate deficits in the north. Intense deficits will continue to emerge in central New Caledonia.

From May through July deficit anomalies in Australia will be primarily mild, with moderate deficits across the north and some severe deficits near Darwin (NT), Busselton (WA), and Tasmania. Moderate surpluses are expected to persist in Kimberley region (WA). Conditions in New Caledonia are forecast to return to near-normal. Deficits may linger in southern South Island, New Zealand

The forecast for the final months – August through October – indicates intense deficits emerging across northernmost Australia.

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

IMPACTS
The city of Dunedin in southeastern New Zealand recorded its hottest day on record January 16, reaching a high of 35 degrees Celsius (95 degrees Fahrenheit). The National Institute of Water and Atmospheric Research (NIWA) reports that the region is “extremely dry.” Indeed, Otago’s river levels have plummeted in the current drought, with one river at its lowest since records began in 1982. Much of the region was on fire alert with precautions issued and fire permits suspended. Fire broke out at a timber yard near Dunedin that forced the evacuation of 100 households. Six helicopters, 100 firefighters, and 25 fire trucks were deployed.

Water quality and allocation have become hot-button issues in New Zealand as nitrogen and phosphorus run-off from the nation's dairy industry trigger toxic algal blooms, threatening drinking water, beach activities, and the nation's "clean, green" reputation. And as the population increases, competition for water rights increases, sometimes pitting Kiwi - the nickname for New Zealanders - against Iwi - native Maori tribes.

The race to feed a world population that could reach 10 billion by 2050 may have taken a small but significant step forward with recent research into a wild rice variety from northern Australia. Its genetic tree revealed a potential for enhancing commercial rice varieties to increase resistance to drought. While rice breeding amid increasing water stress is an extensive area of research, this particular variety was relatively under-explored until now due to its shared habitat with Australian crocodiles.

The tiny Polynesian kingdom of Tonga declared a state of emergency in February when Category 4 Cyclone Gita ravaged the Pacific nation, destroying the Parliament house and blowing the roofs off 40 percent of residential homes in the capital. Flooding and fallen trees added to the damage, creating what one National Emergency Office spokesman described as “the worst situation” in his 30-year career. New Zealand has extended an initial aid package of NZD $540,000 (USD $396,792). Prior to landing in Tonga, Cyclone Gita hit Samoa and American Samoa as a Category 1 storm, causing extensive damage. The US will provide emergency resources for 50,000 residents of its Samoan territory.

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