It has rained but the Drought Isn’t Over
After the very dry 2019, the end of January and February has seen an extended period of rain along the Eastern side of Australia. The rivers and dams in many regional towns have now been replenished and green grass is appearing in the paddocks. Some farmers believe the soil is moist enough to sow a crop but this doesn’t mean that the drought is over.
In an article in ‘The Conversation’ published on Monday, meteorologists from the Bureau of Meteorology, set out the position:
“In the three years to January 2020 some 33% of Australia and 96% of New South Wales had serious or severe rainfall deficiencies. In the most-affected regions, rainfall over the past three years was around half the long-term average.
Based on rainfall so far in February, the areas suffering serious to severe deficiencies has only slightly improved (to around 30% of Australia and 90% of NSW).
In other words, while some areas have seen excellent rainfall, others have not – so the overall relief from meteorological drought so far this year is modest.”
2019 was the driest year on record and the current drought is the worst in the last 120 years. It has led to a significant fall in agricultural production as well as mass fish kills, severe water restrictions and damage to important internationally recognised wetlands.
The Murray-Darling Basin experienced above-average rainfall in just five months from 2017 to 2019. The total three-year rainfall was a record low 917mm – that’s 548mm below average.
Dry conditions have also affected all east coast urban regions south of Townsville, including Brisbane, Sydney, Canberra and Melbourne.
The advent of rain is due to a change in the Indian Ocean currents which are now bringing warm water to the west coast. This has generated monsoon weather and cyclones in Northern Australia and rain in Eastern Australia.
The national rainfall for January was slightly above average (89mm), though NSW, South Australia but the Murray-Darling Basin again recorded below average rainfall overall.
However, drought is not all about rain: soil moisture is just as important. During the long drought the soil moisture in many parts of Australia was zero or close to zero. At the moment the soil moisture in the food bowl regions of Australia including Queensland, NSW, Victoria and South Australia is only 23%. This makes the planting of crops an expensive gamble for many farmers.
According to the meteorologists a small volume of water will likely make it down the Darling, it will take more than a month. This is because losses to evaporation and seepage into the riverbed will be high.
But not enough rain has fallen in the right places to significantly impact dam levels in northern NSW, which have been critically low over the past year.
Collectively, storage volumes in major dams in the northern Murray Darling Basin have only increased by around 5%. The heaviest inland rain was downstream on the plains rather than on the western slopes of the Great Dividing Range, which feed the dams.
The predictions are that rainfall in the coming months will be patchy. This does not augur well for farmers who need an extended period of wet for their land to recover and their dams to fill. At the moment the odds of good rain are still less than 50%.