Echunga dam: Department unable to say if key recommendations from safety report were put in place

The Environment Dept was given a raft of recommendations to ensure thousands of dams were made safe – it says all it did was begin an awareness campaign.

A risk rating system and a register for vulnerable dams were among key recommendations of an Environment Department report in 2020, it can be revealed.

But in the wake of this week’s near disaster when a weakened dam at Echunga threatened to flood the town, the department could not say if they were put in place.

The “position paper” acknowledges “significant scope for improvement of dam safety management regulation”.

It identifies the need for a dam register that includes location, size, and failure risk, plus a risk rating method.

“Dam-failure flood risks are significant and exist at both the individual and cumulative levels within catchments,” it says.

SES volunteers on the edge of the dam at Echunga after a night of reducing the water levels. Picture: Kelly Barnes

“A register of dams in South Australia linked to a spatial database would be beneficial for both water resource management and emergency management.

“A method for assigning failure-risk ratings to dams will be scoped … It will identify the likelihood of a dam failing based on factors such as design and catchment size.”

It would take into consideration “area of impact and presence of dwellings, roads, other buildings or infrastructure.”

Poor dam design and maintenance was already identified in previous reports after heavy flooding in 2016, in which 250 growers across the Northern Adelaide Plains suffered more than $51m in damages.

A department spokesman failed to confirm what action had been taken on the position paper’s recommendations other than an annual education campaign for landowners.

“Following the 2016 floods, the department, in collaboration with Landscape Boards and SASES (State Emergency Service), developed publicly-available guidelines for private dam maintenance,” he said.

“SASES and the department runs an annual awareness campaign to remind landholders about the need to maintain dams.”

SES crews begin to pump water from the dam the day before it was declared safe. Picture: Kelly Barnes

After the Echunga scare this week, Hills and Fleurieu Landscape Board water resources team leader Paul Wainwright warned many of the estimated 22,000 dams across the Mount Lofty Ranges presented an “elevated level of risk” due to a very wet winter.

“There are many dams around at 100 per cent and they are spilling,” he said.

“Many of these dams were built prior to regulations coming into play so there are some in what you might consider to be riskier locations that might be in proximity to a township.”

Emergency services spent more than 24 hours working to prevent the farm dam collapsing.

SES incident control Craig Brassington said on Thursday afternoon the dam’s level had been lowered 3m by the control effort.

However, he said the town was lucky to escape flooding.

The Environment Department spokesman said it would now provide advice on how government could better work with landowners in managing dams on private properties to avoid similar situations.