A dam wall in the Adelaide Hills town of Echunga is still at risk of collapsing and residents will have to spend at least another 24 hours away from their homes, the South Australian State Emergency Service (SES) says.
The SES said it was trying to reduce the level of water in the private dam by 1.5 metres to reduce pressure on the dam wall.
Steep hills on the property have made it hard to get a larger pump near the dam, SES district officer Craig Bressington said.
Mr Bressington said a fourth pump had now been deployed to help reduce the water level.
“We are dropping the dam approximately 60 to 80 millimetres an hour, It’s going down reasonably fast," he said.
“To get it to a safe level it’s going to take 18-24 hours.
“We’ve put a number of sandpits around key locations around town.”
"The only relief we can do is via the pumps."
Echunga is a small town in the Adelaide Hills, about 34 kilometres south-east of Adelaide.
The dam is located on farming land about 500 metres east of the town centre, between Marianna Street and Church Hill Road.
If the path is clear, the SES has urged people to relocate elsewhere outside of the warning area, or to the Echunga Football Club.
There was "minor slippage" of the dam wall on Tuesday night, and the SES is worried more slippage could occur.
“Worst case scenario, the main wall of the dam gives way, that's allowing the water obviously to come down into the town," Mr Bressington said.
"You're looking at up to about 30, 40 properties that could possibly be inundated with water."
A town meeting was held on Wednesday afternoon and SES members will doorknock the warning area to make sure people have left their homes.
Some people have refused to leave despite warnings.
"We just don't want them to be there in case it does collapse and then that's going to be a bigger issue for us," Mr Bressington said.
The dam, about 500 metres upstream of the town, contains about 10 megalitres of water and could flood the area with ankle-deep water.
