Treasurer Stephen Mullighan said the 2023/24 surplus of $413 million was $107 million higher than projected in the June budget, setting the scene for further surpluses in the next four years.
Delivering the midyear budget review on Tuesday, Mr Mullighan said the state's strong economic position will support a boost in infrastructure spending and provide more funding for health, housing and child protection.
The budget update forecasts a $201 million operating surplus for this 2024/25 financial year, with projections for more across the forward estimates.
Treasurer Stephen Mullighan believes South Australia is in a strong economic position. (Matt Turner/AAP PHOTOS)
Mr Mullighan said achieving budget surpluses was important as the state embarks on a large infrastructure program, led by the North-South Corridor tunnels and the new Women's and Children's Hospital projects.
Net debt is expected to rise to $46 billion by the end of the forward estimates, largely due to the bringing forward of spending for the tunnels.
State tax revenue estimates have been revised up by $204 million for 2024/25 and by a further $329 million over the three years to 2027/28, mainly due to improved conveyance duty revenues from higher residential property prices and transactions, as well as continuing strength in the economy.
While net debt is worse than forecast, interest expenses are about $54 million per annum on average lower than estimated in the June budget, due to lower-than-projected interest rates.
"Importantly, the government's debt position remains affordable within the size of the overall budget, with the key debt metric, the net debt to revenue ratio, projected to be 25 percentage points lower than what the former Liberal government forecast it to be this financial year," Mr Mullighan said.
South Australia's budget surplus has been revised upwards since June. (Michael Errey/AAP PHOTOS)
The budget update also provided additional funding for key initiatives including $672.5 million over four years to meet growing demand in the public health system.
"We continue to combat larger than expected numbers of elderly South Australians stranded in hospital beds who should be in aged care places," Mr Mullighan said.
"That continues to drive up costs while we go through the process of negotiating a better health funding agreement with the Commonwealth."
Opposition Leader Vincent Tarzia said the government was "incapable of responsible fiscal management" and the Treasurer needed to produce a debt management plan.
"Net debt has ballooned out by almost $2 billion since the government's budget six months ago and since taking office, they have spent more than $2 million on extravagant ministerial travel and more than $100 million on government advertising," he said.
"This government will continue to hide behind the facade of small operating surpluses to cover up the spiralling debt, budget overruns and delayed infrastructure projects."