Intensive care units at Dunedin and Invercargill hospitals would have been overwhelmed before the end of this month if the worst-case scenario for Covid-19 had played out.
And their wards would have been maxed out soon after, according to new modelling figures released by the Southern District Health Board.
They show just how badly the region - which was hit early by Covid - could have fared if the lockdown had not been effective.
In the worst-case scenario there would have been no more room in intensive care by 25 May, the models, which were done early in the lockdown, predicted.
As cases peaked, 56 people would have needed care but the maximum intensive care capacity using every Covid-19 emergency measure was 32 beds.
Southern District Health Board chief executive Chris Fleming said the figures showed how devastating Covid could have been for the region, which had two early clusters.
It may have sent patients to other regions for care.
"But that would have depended on whether that worst-case scenario had hit simultaneously around the country," he said.
If that happened, not everyone would have been able to have intensive care.
"They would have had to look at innovative ways around how to best care for people in what would have been substandard settings for care," he said.
- If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs) or call your GP
The figures, in a report to tomorrow's Southern DHB meeting, were from modelling done on 6 April.
In the worst-case scenario, they showed by 27 June, the region's hospitals would also have been full.
They also modelled a less serious scenario, where intensive care would have been at capacity on 7 June and, at its peak, all the emergency extra beds would have been used but would have been enough.
The normal intensive care capacity for the Southern DHB was just two beds, but like most around the country, it had planned to increase that if needed, including by using operating theatres.
Fleming said as hospital services went back to normal, it would still be ready to escalate to 32 beds if it needed to.
But its latest modelling suggested it would need only a maximum of four beds, if that, he said.
That depended on cases staying low at level 3, he said.