SA’s State Emergency Service have issued a watch and act warning for residents of Hope Forest, a town of about 150 people 40km south of Adelaide.
The dam is at a high risk of failure, the SASES said in a statement, and properties near the intersection of Bevan Road, Phillips Road and Verrall Road in the vicinity of Brookman Road could be subject to sudden flooding.
The warning asked residents monitor weather conditions and warnings, follow emergency plans and prepare for flooding.
If people planned to leave, they should consider leaving now, SASES said at 7pm on Saturday.
For SES assistance phone 132 500 and if the matter is life threatening call triple-zero.
The Bureau of Meteorology issued a severe weather warning with wind gusts predicted to peak at around 90km/h on Saturday night over the Mount Lofty Ranges.
The BOM said locations which could be affected by damaging winds included Mount Barker, Murray Bridge, Victor Harbor, Strathalbyn and Mannum.
“Damaging wind gusts are expected to ease below warning thresholds during Sunday afternoon,” the alert stated.
“Recent rainfall has led to saturated soil, so trees may be more susceptible to strong and gusty winds.”
The BOM also issued flood warnings for parts of the North West and North East Pastoral Districts ahead of more rain lashing South Australia.
Showers and increasing rain are forecast to develop from Monday with flooding possible from Tuesday.
The weather bureau warned that communities may be cut off with roads, travel and transport being affected.