Extreme weather sees Hydro Tasmania dam levels recover after historically dry period

If there’s a silver lining to the extreme rainfall Tasmania has experienced over the last week, it’s that dam levels have recovered after a historically dry 12 months.

Meadowbank Dam and power station, north of New Norfolk. Picture: Chris Kidd

Water levels in Hydro Tasmania’s dams have risen by more than 5 per cent in the past week amid extreme rainfall, putting the state-owned generator in “a good position” ahead of the summer period after a historically dry 12 months.

The state has increasingly been relying on importing energy from mainland coal and gas sources due to low dam levels but the recent weather could see that change.

Twenty-eight of Hydro’s more than 50 water storages are currently spilling, a spokeswoman for the government business said.

The majority of Hydro lakes are known as ‘run of the river’ storages, meaning they don’t hold large amounts of water. During significant rainfall events, these tend to fill up rapidly and begin to spill.

Gordon Dam. Picture: Philip Young

As a result, the total energy in storage – the total amount of water currently in all Hydro storages – has increased by 5 per cent.

“This extra water has placed storages in a good position for the upcoming summer period,” the spokeswoman said.

She said run of the river dams did not increase the risk of flooding downstream, were designed to “handle these kinds of weather events”, and remained operational.

As at Wednesday morning, two of Hydro’s largest storages, Great Lake and Lake Gordon, were still 14 metres and 23 metres from full, respectively.

Hydro head of generation operations Jack Penny told ABC Radio on Tuesday that the increased water levels were “welcomed” but the business remained focused on “managing the emergency situation … and keeping our people and assets safe”.

“We’ve had an exceptionally dry 12 months … one of the driest in the last 100 years,” he said.

Poatina Power Station penstock pipeline.

“What that’s meant is Great Lake and the energy we’ve been using from Gordon and Great Lake has been really important. They’re the storages we can use during those drought conditions.

“And Great Lake has gone up 2 per cent over the last week, which is very welcome relief.”

Minor flooding was easing below Meadowbank Dam in the Derwent Valley on Wednesday, the Bureau of Meteorology said.

Hydro announced in August that it would be investing $1.6bn over the next decade into upgrading and modernising its existing network of infrastructure.

The capital works will include major refurbishments of 10 power stations and five dams, such as the Gordon and Poatina power stations, where works are already under way.

It costs Hydro about $100m a year to operate and maintain its hydropower network.

Originally published as Extreme weather sees Hydro Tasmania dam levels recover after historically dry period