The SA Ambulance Service says more volunteers are needed for Bordertown or call-outs may have to come from a neighbouring town.
Four volunteers, with more than 100 years experience between them, have indicated they intend to retire.
Limestone Coast operations manager Andrew Thomas said there was currently a team of 10 but there used to be as many as 25.
He said if more volunteers did not sign up, alternative arrangements would be required.
“If you ring triple-0 you will always get the closest ambulance responding to you,” he said.
“Unfortunately if we’re struggling to find and man the rosters in a town it may mean you might have [a] responder within that town, so one of the volunteers who will respond by themselves and then we’ll back them up and provide another ambulance coming from a neighbouring town.”
He said at least five more people were needed to help ease the pressure on current volunteers.
“We’re concerned obviously that with the reduced numbers we don’t want to be trying to ask more of them but they [are] wanting to obviously still serve their community,” he said.
“We don’t want to be burning them out.
“We want them to have 25 or 30 more years worth of service for the ambulance service.”