Serious and severe rainfall deficiencies, defined as rainfall totals in the lowest 5% to 10% of years since 1900, have extended across north-eastern New South Wales, bordering areas of Queensland, parts of Victoria's west-facing coast, and western, northern, and eastern Tasmania for the four months ending April 2026, according to Australia's Bureau of Meteorology. The New South Wales Northern Tablelands region recorded its lowest rainfall on record for the period, surpassing all comparable periods since 1900.
Since March 2026, deficiency areas have increased in both extent and severity across north-eastern New South Wales and bordering Queensland. Tasmania's deficiency areas also expanded during the same period. Year-to-date deficiencies in Western Australia largely cleared by April's end.
Murray-Darling Basin Storage Levels Drop 7.4% Below Last Year
National water storage across 302 public facilities finished April at 67.2% of capacity, down 2.1% from March. The Murray-Darling Basin, which underpins a significant share of Australia's agricultural water supply, ended April at 47.7%, a decline of 7.4% compared to the same point in 2025. The southern Murray-Darling Basin fell further, finishing at 45.7% capacity, approximately 8.4% below last year.
Hume Dam, Australia's seventh-largest reservoir, dropped 5.4% during April to finish at 21.6%. Menindee Lakes in western New South Wales closed the month at 25.7% capacity. The Bureau attributed the drawdown to dry catchment conditions combined with elevated irrigation season water use from October through March, which increased storage withdrawals while limiting inflows.
Urban Storages in Melbourne, Adelaide, and Perth Under Sustained Pressure
Most capital city storages remain near or above 80% of accessible capacity, but Melbourne, Adelaide, and Perth are tracking significantly below that baseline. Perth's surface water storages finished April at 36.5%, with the city continuing to rely primarily on desalination and groundwater due to a long-term decline in catchment inflows. Adelaide's storages closed at 44.5%, with six of the city's metropolitan storages at or below 50% capacity.
Melbourne's storages decreased by 2.2% in April, finishing at 65.4%, and have fallen 10.0% since the same point in 2025. The Victorian desalination plant has been activated to support supply to the Melbourne and Geelong areas in response to persistent rainfall deficits and very low catchment inflows.
Soil Moisture and Evaporative Stress Signals Point to Ongoing Agricultural Risk
Root zone soil moisture across north-eastern New South Wales and south-eastern Queensland remained very much below average through April, placing approximately 5% of Australia in the lowest soil moisture decile for the month. The Bureau noted that below average soil moisture for extended periods is a key indicator of agricultural drought, affecting crop growth and reducing pasture availability. Elevated evaporative stress, measured by the Evaporative Stress Index, expanded inland and along the coast in New South Wales and southern Queensland during April. Significantly elevated stress areas increased in coastal north-eastern New South Wales, adjacent south-eastern Queensland, and north-eastern Tasmania.
