Australia & New Zealand: Water deficits will persist in New Zealand

Australia & New Zealand: Water deficits will persist in New Zealand

28 June 2021

THE BIG PICTURE
The 12-month forecast through February 2022 indicates pockets of moderate surplus in New South Wales, Australia from the eastern Murray-Darling Basin to the coast. Near the mouth of the Murray River in South Australia, intense surpluses and transitional conditions are expected.

In Queensland, a small pocket of intense deficit is expected on the coast north of Townsville, but a few pockets of moderate surplus are forecast in the Cape York Peninsula of the Far North.

Surpluses are also forecast in Top End, Northern Territory in the region of the Daly and Katherine Rivers.

Normal water conditions are expected in most of Western Australia with surpluses in the Avon River Basin east of Perth. Moderate surpluses are forecast in western South Australia. In Tasmania, moderate deficits are expected in much of the island though anomalies will be severe in the southwest.

Deficits are also forecast for several regions in New Zealand including moderate to severe anomalies near Lake Taupo and the Waikato River area on North Island. Anomalies will be exceptional near South Island’s three glacial lakes - Pukaki, Tekapo, and Ōhau - in the Waitaki River Watershed, and moderate in pockets along the east coast.

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

The forecast through August indicates that surpluses in southeastern Australia will shrink, retreating from the Upper Murray River region but persisting between the Barwon and Macquarie Rivers in northeastern New South Wales and along the state’s southern border east of the Australian Alps. Intense surpluses and transitional conditions (pink/purple) will persist in the Lower Murray River region of South Australia. In Tasmania, deficits will increase, with exceptional deficits emerging around Lakes Pedder and Gordon, severe deficits west of the Tamar River, and moderate deficits in the Derwent Estuary and Hobart. Back in mainland Australia, surpluses will intensify in the Atherton Tableland in northern Queensland and persist in a pocket in eastern Cape York. Intense deficits will emerge in coastal Northern Territory and transitional conditions around Katherine in areas of former surplus. In Western Australia, intense surpluses will re-emerge southwest of the Gibson Desert but will shrink in the Avon River Watershed east of Perth.

In New Zealand, deficits will shrink considerably in South Island leaving a few lingering moderate pockets, but will persist in North Island becoming exceptional around Lake Taupo in the Waikato River region. Deficit anomalies in New Caledonia will moderate.

From September through November, moderate surpluses will persist in northeastern New South Wales and some pockets along the coast reaching south. Intense surpluses will increase in the Lower Murray River region in South Australia. In northern Queensland, severe surpluses will persist in the Atherton Tableland and moderate surpluses in a pocket of eastern Cape York. Surpluses will re-emerge near Katherine in Top End, Northern Territory and near the Gibson Desert in Western Australia but will nearly disappear east of Perth. Deficits will downgrade considerably in Tasmania and nearly disappear in New Zealand and New Caledonia.

The forecast for the final months – December 2021 through February 2022 – indicates that surpluses will shrink in northeastern New South Wales but increase from Canberra into eastern Victoria. In the Lower Murray region intense surpluses will persist but anomalies elsewhere in the nation will nearly disappear. Some moderate surpluses will emerge in New Caledonia.

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

IMPACTS
Year after year of extreme weather - drought, wildfires, flooding - have now set the stage for a plague of mice in Australia’s southern and eastern agricultural regions. The recent prolonged rainfall led to bumper crops, voraciously devoured by what some say is an unprecedented invasion of rodents. The creatures have also damaged farm equipment, raided supermarkets, caused power outages and even house fires. Mouse carcasses and excrement are contaminating farm water tanks. Losses at one farm alone total AU $130,000 (~US $98,400). Agricultural officials in New South Wales predict losses of AU $1 billion (US $775 million).

Heavy rainfall in New Zealand’s Canterbury region at the end of May resulted in flooding that forced hundreds to evacuate. Helicopter rescue squads plucked people from rooftops after 40 centimeters (16 inches) of rain doused the region, 2 to 3 months worth of rain, over a long weekend. One rancher lost 40 percent of his herd, drowned in floodwaters, and several bridges washed away. Recent drought conditions left the ground too parched to absorb the vast amount of water, creating dangerous runoff.

Reservoirs in Auckland, New Zealand were about half full in early June. Commercial and residential water use restrictions, invoked a year ago, remain.

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

Many analyses reported in ISciences-authored blog posts are based on data generated by the ISciences Water Security Indicator Model (WSIM). Other sources, if used, are referenced in footnotes accompanying individual posts. WSIM is a validated capability that produces monthly reports on current and forecast global freshwater surpluses and deficits with lead times of 1-9 months at 0.25°x0.25° resolution. This capability has been in continuous operation since April 2011 and has proven to provide reliable forecasts of emerging water security concerns in that time-frame. WSIM has the ability to assess the impacts of water anomalies on people, agriculture, and electricity generation. Detailed data, customized visualizations, and reports are available for purchase.

For more information contact info@isciences.com.

Copyright 2022 ISCIENCES, L.L.C. Global Water Monitor & Forecast Watch List is the property of ISCIENCES, L.L.C. It is protected by U.S. copyright laws and may not be reproduced in any way without the written permission of ISCIENCES, L.L.C. The user assumes the entire risk related to its use of information on ISCIENCES, L.L.C. Web pages, including information derived from Water Security Indicators Model (WSIM). This information may include forecasts, projections and other predictive statements that represent ISCIENCES, L.L.C.’s assumptions and expectations in light of currently available information and using the highest professional standards. Actual results may differ from those projected. Consequently, no guarantee is presented or implied as to the accuracy of specific forecasts, projections or predictive statements contained herein. ISCIENCES, L.L.C. provides such information "as is," and disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will ISCIENCES, L.L.C. be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data.