The state MP representing the Barossa Valley says safety improvements may need to be made at the Whispering Wall following the deaths of a man and a baby girl at the tourist site yesterday afternoon.
The man and the girl died after falling 36 metres from the top of the dam wall at the Barossa Reservoir about 4:30pm yesterday.
The man had already died by the time paramedics arrived.
They could not save the girl.
SA Water, which operates the dam, about 75 kilometres north-east of Adelaide, said it would be closed to tourists today.
Schubert MP Stephan Knoll described the incident as "awful".
"Because it is a very popular tourist attraction and something that young people and kids of generations have been going to visit and not before have we heard or seen of an incident like this.
"But, having said that, if things need to be done to modify the structure, then that's something we need to look at."
Police have not revealed any more details about how the pair fell from the dam wall, except to say witnesses saw them "go over the edge of the wall and fall to the ground".
A nearby neighbour to the reservoir, Zac Singlehurt, said he was surprised to hear there had been deaths at the wall.
"It's been pretty safe, I've not heard of any situations previously," Mr Singlehurt said.
"It used to not have railing — my grandparents have told me stories about riding their bikes across it with no railing and it's crazy to think [this happened] now that there is all that safety already in place."
Another neighbour, Gwyneth Helbers, said it was a very safe walk with a "nice high fence".
"There's no way you could fall over it," she said.
The reservoir opened in 1902 and the dam wall became known as the Whispering Wall because of its unique acoustic qualities allowing people more than 100 metres apart, from one side of the wall to the other, to talk in whispers.
Fences run either side of a path along the dam wall.
'Beautiful and resilient' community
After a spate of recent road crashes in the Barossa and now this latest incident, Mr Knoll said the "beautiful and resilient" local community would hold together.
"These kinds of things in our community do weigh differently and more heavily because everybody knows everybody," he said.
It is not known if the man or the girl came from the Barossa Valley.
