Australia & New Zealand: Water surplus will persist in E Australia

22 July 2022

THE BIG PICTURE
The 12-month forecast through March 2023 indicates water surpluses in eastern Australia from the Wide Bay-Burnett region of Queensland through East Gippsland, Victoria, and inland through the Central West region of New South Wales. Anomalies will be moderate overall with a few pockets of severe intensity.

In Queensland’s Far North, surpluses are expected north of the Holroyd River in Cape York Peninsula. Elsewhere in Australia, pockets of surplus are forecast in the Upper Avon River catchment of Western Australia and near the state’s central southern coast, and in the Lower Murray River region of South Australia.

Exceptional deficits will dominate southwestern Tasmania, the Derwent Estuary, and Hobart, and though downgrading, deficits will be severe in the northwest. Across the Bass Strait, moderate to severe deficits will skirt much of coastal Victoria through Melbourne. In Western Australia, moderate to severe deficits are expected in the southwest from the Wheatbelt’s coastal region through Perth, becoming more intense as they reach Albany in the south. Moderate deficits are forecast in the state’s south-central area in the Goldfields-Esperance region and in the Fitzroy and Ord River regions of the Kimberley in the north.

In New Zealand, extreme deficits are predicted for Southland in South Island, downgrading through the Otago and Canterbury regions. In North Island, surpluses are forecast in East Cape and Northland.

FORECAST BREAKDOWN
The 3-month maps (below) show the evolving conditions in greater detail.

The forecast through September indicates that widespread surpluses in eastern Australia will increase. Anomalies will intensify west of Brisbane, Queensland, becoming extreme, and will increase west of Rockhampton. Mixed conditions are expected in Queensland’s Far North. In New South Wales, severe surpluses will increase in the northeast and moderate surpluses will emerge on the Darling River. Across northern Australia, generally moderate deficits will emerge in Arnhem Land in Top End, Northern Territory, and exceptional deficits in the Kimberly in Western Australia (WA). Deficits will linger on WA’s southwest coast from Perth to Albany while surpluses linger in the Avon River region and re-emerge in pockets of the Great Victoria Desert. Along much of Victoria’s coast, deficits will persist, becoming exceptional in Cape Otway. Deficits will persist in Tasmania, downgrading in the west but severe in Hobart and extreme in the Derwent Estuary. Deficits in South Island, New Zealand will shrink but remain intense along the southeast coast near Dunedin. Some surpluses will linger in North Island on the Bay of Plenty and north of Auckland. Moderate deficits are expected in northern New Caledonia.

From October through December, widespread surpluses will persist in eastern Australia, moderate overall but extreme west of Brisbane and severe in New South Wales west of Armidale and near Dubbo. Surpluses will re-emerge in the Cape York Peninsula of Far North Queensland and emerge on the coast near Cairns. Surpluses will also emerge in Top End, Northern Territory while deficits in Arnhem Land retreat. Moderate to severe deficits will linger on Victoria’s western coast, in southern Tasmania, and in southern regions of South Island, New Zealand. Surpluses will emerge in New Caledonia.

The forecast for the final months – January through March 2023 – indicates some lingering surpluses in southeastern Queensland and eastern New South Wales, Cape York, and New Caledonia. Moderate deficits will persist in Victoria’s coastal southwest and will emerge in pockets spanning Victoria’s border into South Australia.

Please note that WSIM forecast skill declines with longer lead times.

IMPACTS
For the fourth time in less than a year, Sydney - the capital of New South Wales, Australia and home to over 5 million people - faced flooding. Torrential rainfall in early July, a meter and a half (nearly five feet) over 24 hours, deluged one area and over 30,000 people were advised to evacuate. As one resident of Windsor, a northern suburb wryly noted, “at least we haven’t lost as much — because we’d already lost it all beforehand.”

Just halfway through the month, July 2022 has already been declared Sydney’s wettest July on record. The federal government declared a natural disaster for 23 local areas enabling disaster relief funds.

NOTE ON ADMINISTRATIVE BOUNDARIES
There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

Subscribe to our monthly Water Watch List

Search blog categories

Search blog tags