Power station flooding a summer energy risk for Victoria

According to the Australian Energy Market Operator, the biggest cloud hanging over reliable energy this summer is the potential unavailability of the Yallourn power station due to flooding.

Environment and community groups are demanding a government inquiry into how heavy flooding of the Morwell River diversion in June caused massive cracking in the banks of the Yallourn coal mine and forced the state government to declare an “energy emergency”.

Yallourn power station and coal mine which is still not operating  at full capacity after flooding in June.

Yallourn power station and coal mine which is still not operating at full capacity after flooding in June.Credit:Joe Armao

The market operator’s 2021 electricity reliability report, released this week, highlights the potential problem at Yallourn where the cracks in the mine wall have put it at greater risk of flooding during future heavy rain events.

“Now the electricity market operator has said structural problems at Yallourn pose the biggest risk to the grid this summer we need a proper, independent inquiry to get to the bottom of what went wrong,” said Bronya Lipski, a lawyer at Environmental Justice Australia, in a joint letter to Premier Daniel Andrews.

Environmental Justice Australia, Environment Victoria and fishing and community groups have written to Mr Andrews, arguing an independent investigation of the causes would provide confidence that future problems at the mine can be avoided.

In 2012, the Morwell River diversion failed catastrophically after heavy rainfall and filled the mine pit with up to 60 billion litres of water. It took two years and $150 million to repair and was the subject of a government inquiry.

Andrew Watkins, head of the Bureau of Meteorology’s Operational Climate Services, said the outlook for spring was for wetter-than-average conditions, particularly in the east where it is already “fairly wet”.

“We have a slightly increased risk of flooding in those areas,” Dr Watkins said in a video statement.

Environment Victoria campaigns manager Nicholas Aberle asked if lessons had been learnt from the previous Morwell River diversion collapse in 2012.

“The river diversion is on private land, but the damage affects the Morwell River which supplies freshwater to the internationally recognised Gippsland Lakes downstream,” Mr Aberle said. “That makes this a matter of serious public interest.”

The flooded Yallourn mine in 2012.

The flooded Yallourn mine in 2012.Credit:Luis Enrique Ascui

Relying on a few coal-burning power stations in a single area leaves Victoria vulnerable, he said.

“We need to speed up the transition to renewable energy and storage across the state.”

Yallourn currently supplies about 20 per cent of Victoria’s energy and is set to close in 2028.

Repair work on the cracked mine walls will see EnergyAustralia divert normal winter flows from the Morwell River around the damaged diversion and into the Latrobe River.

This will dry out the diversion, enabling engineers to undertake necessary repairs. Construction and repairs are estimated to take up to 18 months.

A spokesperson for the government said it would closely monitor repairs to ensure that the local community, water entitlement holders and the environment were protected.

On Tuesday, the Minister for Energy, Environment and Climate Change, Lily D’Ambrosio, launched Victoria’s second renewable energy auction, which aims to attract investors to bring at least 600 megawatts of renewable energy capacity to the state.

This will match the government’s electricity consumption for Victorian hospitals and schools, Melbourne’s entire train network and a range of other government infrastructure and services.

Ms D’Ambrosio said the projects were expected to create at least 2000 new jobs and attract $1 billion in capital expenditure.

Miki Perkins is a senior journalist and Environment Reporter at The Age.