Echunga residents in waiting game as dam threatens to collapse
Residents in about 14 Echunga homes have refused to leave despite urgent warnings a dam wall could collapse any second and inundate their homes.
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Some residents have refused to leave homes directly downstream of a failing dam in the Adelaide Hills, where the State Emergency Service is urgently draining water.
The SES on Tuesday night warned about 40 homes were in danger of being flooded by a collapsing dam wall in Echunga and would be “inundated” if the wall failed.
Volunteers have created a spillway and were extracting about 12,000 litres a minute from the dam with three medium-sized pumps.
A fourth, larger pump has now doubled the pumping capacity to empty the 35m by 50m dam, which is filling constantly from run-off down the hill.
The dam is unlikely to be at a safe level until about 4pm Thursday, at current pumping rates. By Thursday morning, emergency crews had lowered the water level by more than two metres and the SES will consult engineers to understand the necessary next steps.
However an emergency warning message remains in place for the Adelaide Hills area.
The SES has created an emergency evacuation area around the dam, but some residents in about 14 properties have refused to leave their homes, SES incident controller Craig Brassington said.
“We’ve been there with police encouraging them to leave, we’ve made a note of where they are,” he said. “We have swift-water rescue teams around, just in case.”
The defence force is also on standby, he said.
There’s been no more slippage of the dam wall on Wednesday afternoon, but the town won’t be safe until the water level has dropped by at least two metres, which is expected to happen around 4-5pm on Thursday.
It was about 30cm from the top when the SES was alerted, Mr Brassington said, and as of 4pm it had fallen about 80cm.
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“We’ve increased the pumping capacity quite significantly up to about 80-85 per cent out into the main drain going under the town,” he said.
“We’re dropping anywhere between 70-80mm an hour in the dam presently.”
However, he said the risk hadn’t lessened. “If we’re getting more slippage, the dam could still blow out – we don’t know if there’s more slippage, it depends about the pressure on the wall.”
Should the dam wall blow, a siren will go off – water will hit the closest houses within about 30 seconds, Mr Brassington said.
“It’s not looking like a tsunami that’s going to come blowing through, it’s going to be down the creek, it will hit that road on West Street, and then dissipate across – the properties on West Street will get inundated, then it will dissipate across the streets.”
Residents in the high-risk zone will be unable to return home to their properties on Wednesday night with emergency accomodation being sourced for those who have nowhere else to go.
“I’d say it’s about 30 residents we’ll be housing,” he said.
Mr Brassington said the dam owner had been “very co-operative”.
“He managed to get an excavator down there, most people wouldn’t have been able to get that down, and he built a channel all day yesterday afternoon before dark – the owner has been extremely helpful.”
The dam is still holding despite some “slippage” on the rear wall. Authorities are unsure how much water is in the dam but it’s estimated at least 10 megalitres – or about four Olympic-sized swimming pools.
Earlier on Wednesday Mr Brassington said the SES had managed to pump about half a metre off the dam but they were being hampered by the drainage pipes under Echunga, which are only 18in wide. Access to the steep area is also difficult.
But Mr Brassington said pumping had to be gradual to slowly reduce pressure on the wall – or it would collapse.
“We need to get something like a metre and a half depth to make it a safe area,” he said.
“It’s probably not a race against time, we’re just trying to mitigate the risk.”
There’s about a 30 per cent chance the wall will collapse, flooding the homes.
Mr Brassington said there was “constant” water flow into the dam.
“It’s at the bottom of the hill – we are trying to pump out more than what’s coming in, we’re ahead of the curve.
“We’re trying to get close to 90% of the water out of the dam so it can go through the drains through the town, so it doesn’t impact anywhere else.
“(The wall) is holding up at the moment. We’re expecting some slippage, just because of reducing the water. It’s made its integrity dangerous (at the wall), but at the moment it’s still holding.”
The SES is working on getting another, larger pump in but access is difficult because there is no road down to the dam, which is at the bottom of a steep hill.
Pumping is expected to take between 24 hours before water is at a safe level for residents to return home. If a larger pump can be used, it could be about 18 hours.
“The only release we can do is by the pumps, the pipes that go under the town is an 18in pipe, so we can’t pump any more than that amount of water out of the dam – we’re approximately at about 50-75% of the pipe at the moment,” Mr Brassington said.
“Because of the side of the wall, if we take too much pressure off, or put too much pressure against it, it’s more than likely to give away.”
WATCH: ZOOM IN TO SEE THE FLOOD RISK ZONE
Despite the risk, some people are still in the evacuation area. The SES will urge them to leave during another door knock this afternoon.
“Some people will have gone to work but when they return, they can’t go home.
“Residents cannot go home – there is exclusion zone around their homes – we don’t want them there in case it does collapse.
“To get it down to safe level, it’ll be about 24 hours – if we get the extra pump in, that’s down to 18 hours.
“We can’t gauge how much water is in the dam because it’s been there for such a long time so it fills up with silt. It’s been more used for retention than a dam.”
RESIDENTS FEAR FOR THEIR HOMES
About 65 Echunga residents have been asked to leave their homes and can’t return until the SES is confident the flooding threat has passed.
Mark Badcock and Tracey Wadsley have spent most of the day sandbagging their property on Adelaide Rd in preparation for the worst.
“We’re just trying to limit the damage if it does happen,” Mr Badcock said.
“We’ve been putting membranes around the doors and any openings to the property.
“Now it’s basically just wait and see, our fingers are crossed.”
He said he rents out one part of the property while the other side is used as an entertainment shop.
“My friends evacuated this morning they just thought it would be better to be safe than sorry,” he said.
Mr Badcock said a catastrophic failure at the dam would definitely have an impact on the property.
“How drastic that is, who knows, but I’ve heard reports it could be up to a metre high of water,” he said.
“If it’s a small flow, it might just go under the doors a little bit here, but if it’s a significant flow, our work probably isn’t going to hold it.”
Steve and Jill Hoare were first alerted to a potential problem last night when SES volunteers arrived at their property.
“They were trying to work out where the water would flow and I took them for a bit of a walk because they’ve got no idea of the lay of the land here,” Mr Hoare said.
“They thought it was going to run down the northern side and I said ‘Can you see my house mate, it’s four metres below the road, so the water is going to go that way,’” he said.
He said another knock on the door came early on Wednesday morning.
“We were told to evacuate and that’s the last we’ve heard from the SES,” he said.
“The latest I heard was that they think it’s going to run down Marianna St, I’m not sure how because Marianna St is uphill.”
This is the dam which has partially collapsed and is threatening the town of Echunga. SES crews are working to drain the 10 megalitres of water it holds before the dam wall bursts. Residents below have been evacuated. @10NewsFirstAdlpic.twitter.com/UjWhR2aA1b
— Jase Kemp (@jasetaylorkemp) September 28, 2022
He said he was in the firing line because the Echunga creek runs through his property.
“Where else is the water going to go?” he said.
“We also have a dam and I’ve lost 8ft off the bottom of it so if it hits it’s just going to blow straight through my dam because there’s no surge protection.”
Despite the risks, Mr Hoare said he was optimistic there wouldn’t be much of a problem.
“It all depends how the dam wall goes, if it goes in pieces then it will be probably be all right, it’s a pretty solid wall,” he said.
“We live in the country, it’s just part of where we are.”
Mr Brassington aid emergency accommodation will be provided to residents where required.
#FLOOD Emergency Warning MESSAGE issued for dam failure at Echunga. If you are in this area, prepare for flooding. Relocate outside the warning area or to the safer place at the Echunga Football Club. More info: https://t.co/trkktUn91x ID:342/3
— SASES (@SA_SES) September 27, 2022
The State Emergency Service SA issued an emergency warning on Wednesday morning with a dam at risk of collapsing just 500m from the Echunga township in the Adelaide Hills.
The alert warned the dam on private farming lands between Marianna St and Church Hill Rd could collapse, threatening the safety of residents in the area.
The message advised residents to follow emergency plans, prepare for flooding and to relocate to a safe place outside of the warning area or to the Echunga Football Club.
All roads into Echunga are closed including Aldgate-Strathalbyn Rd, Echunga Rd, Battunga Rd, Strathalbyn Rd and Church Hill Rd.
Renzo and Camilla Gaeten were evacuated from their Marianna St property with their two-year-old son Luca at 5.30am.
Mr Gaeten said they moved into the house about two years ago.
“I never thought this would be a risk … I’m not sure if it’s something that’s happened in the past,” he said.
He said the SES told him to prepare for the worst.
“It’s never nice to get the call that you have to leave your home, but we just have to deal with whatever happens,” he said.
“I’ve got some family just outside of Uraidla, so we’ll just stay there for a few days if we have to.”
Ryan Bailey was also told to leave his property across from the town’s general store.
Mr Bailey said he received a knock on the door at 5:20 earlier this morning.
“The SES were in life jackets and that’s when I thought ‘this is getting too real’,” he said.
“I grabbed my emergency kit and my dog, Paco and went to my parents place in Hahndorf.
“I was told to also open the side gates and roller doors so water could escape more easily.”
Mr Bailey later called the SES and requested sandbags to protect his property.
“We’re not allowed back in, so I thought I need to do something,” he said.
Neighbouring business, HorseMedSA is uphill and not threatened by the dam, but veterinary nurse Kym Austin said the area has received a significant amount of rain in previous days.
“The ground is saturated and the soil is no longer soaking up the water, so it’s flowing into the dams,” she said.
“There’s two dams, it’s the bottom one that is causing the issue.”
Mayo MP Rebekha Sharkie said the electorate of Mayo, which includes Echunga, had grown by 33,000 residents during the last Census period since 2016.
She said towns like Echunga needed better drainage infrastructure.
“I have long been championing the need for federal and state funding to be made available to ensure infrastructure and services are upgraded and expanded as necessary in order to keep up with this growth,” she said.
Emergency Services Minister Joe Szakacs has urged anyone in the area to remain vigilant and monitor emergency warnings.
“The situation at Echunga is an ongoing operational incident,” he said.
“Rely on trusted information and alerts from the SA SES and SA Police.”
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Originally published as Echunga residents in waiting game as dam threatens to collapse
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