Two SA dams are at high risk of failure – one south of Adelaide and one in the Hills, with roads closed after a week of heavy rain.
Waterfall Gully Rd has flooded following 24 hours of relentless rain across SA.
A dam at Hope Forest, south of Adelaide, was at “high risk” of failure, it warned at 6pm on Sunday.
Properties at the intersection of Bevan, Phillips and Verrall roads, were at risk, it said, as well as those around Brookman and Decaux roads.
Road closures were in place for Bevan, Verrall, Phillips and, Brookman Road and Decaux Road.
On Sunday at 10.30am, it also warned a dam at Basket Range on Lobethal Road may fail, with Lobethal Road between Basket Range and Ashton at risk.
Properties along Deep Creek from Lobethal Road towards Elborough Ave may be affected.
Lobethal Rd is closed between Ashton and Basket Range.
#FLOOD Watch and Act MESSAGE issued for dam failure at Basket Range. If you are in this area you should prepare for flooding. Move valuables to a safe place. Consider going to a safer place if the path is clear. More info: ID:537/1
— SASES (@SA_SES) June 25, 2023
Jeffrey Clarke, who owns the Hope Forest property where the dam is located, said he had been alerted to the overflow by a neighbour whose dam water had changed colour.
Mr Clarke, who inherited the property from his late brother, said an existing break in the dam wall was being eroded due to the heavy rainfall.
He said if the dam burst, lower-lying dams would be inundated with water.
“If this one goes it’ll be a domino effect,” Mr Clarke said.” “If we get much more heavy rain in a short period of time then it will go. We’re just hoping it’s slow and steady rather than a big downpour.”
Richard McCarthy has lived at his Brookman Rd home for more than 40 years and has refused to leave.
Despite several warnings from the SES, Mr McCarthy said his home was out of the direct line of flooding if the dam burst.
He said if the dam burst, water would run into the creek several hundred metres from his home
SES commander and swiftwater rescue technician Trevor Arnold said crews and engineers had been monitoring the dam over the past 24 hours.
“There’s a sizeable amount of the same wall that had been eroded away,” he said.
Mr Arnold said there were concerns the dam would inundate the lower-lying dam on the neighbouring property.
“If this dam goes then potentially it will take the other one with it as well which will send a significant amount of water down the catchment.”
Mr Arnold said some residents of nearby properties had left on Saturday night.
“It’s a choice for them whether they stay or go,” he said.
Mr Arnold urged property owners to check their dams.
In a statement, SES chief of staff Derren Halleday said nearby residents of both dams had left their homes.
“We understand three residents – two from Hope Forest and one from Basket Range – have chosen to voluntary relocate.”
He said crews were on-site and drones were being used to monitor both dams.
The SES urges people in the vicinity to monitor weather conditions and warnings and prepare their family and home for flooding.
“If your plan is to leave, if you require time to leave or if you are not prepared, you should consider leaving now.
#FLOOD Watch and Act MESSAGE issued for dam failure at Hope Forest. If you are in this area you should prepare for flooding. Move valuables to a safe place. Consider going to a safer place if the path is clear. More info: ID:536/3
— SASES (@SA_SES) June 24, 2023
Bureau of Meteorology senior meteorologist Simon Timcke said the area surrounding the dam was likely to see showers “on and off” throughout Sunday.
He said Kangaroo Island and the Fleurieu Peninsula would be the wettest parts of SA on Sunday, while the dam was likely to fill more during the day after the area had been hit with heavy rain at the end of last week.
“The catchments are likely to be saturated,” he said.
After a sunny weekend, rain is on the way for many states. ð§ï¸
Extensive Flood Watches have been issued around central Australia.
— Bureau of Meteorology, Australia (@BOM_au) June 24, 2023
The alert comes as the Bureau of Meteorology issues a severe weather warning for damaging winds in Mount Lofty Ranges and parts of Murraylands districts.
“Damaging wind gusts are expected to ease below warning thresholds during Sunday afternoon,” the BOM said on Saturday.
“Recent rainfall has led to saturated soil, so trees may be more susceptible to strong and gusty winds.”
The Bureau says locations which may be affected include Mount Barker, Murray Bridge, Victor Harbor, Strathalbyn and Mannum.
The Bureau of Meteorology also has issued flood warnings for parts of the North West Pastoral District ahead of more rain lashing South Australia.
Flooding is possible from Tuesday following heavy rains last week and developing on Monday.