Winter rainfall boosts power station revegetation project

Revegetation of the former power station site as of March 2018. Photo: Flinders Power.
Revegetation of the former power station site as of March 2018. Photo: Flinders Power.

Rehabilitating the huge ash dam at the former power station site is one of the most challenging tasks revegetation consultant Glenn Christie has ever undertaken.

"I would defy anyone to grow anything in sea water," Christie remarked.

Compounded by almost a year of dry harsh weather with summer temperatures approaching 50C, it's almost an impossible task.

But a recent downpour of winter rain has sparked a germination boom of native plants on the 320-hectare site as it gradually transitions from polluted land back to a natural salt marsh.

Flinders Power has been managing the rehabilitation of the site under the guidance of the Environment Protection Authority since 2016.

Glenn Christie's Succession Ecology was contracted by Flinders Power, in conjunction with McMahon Services, to head up the revegetation efforts - a project which has been unlike any other in the world.

PROJECT PROGRESS: Succession Ecology Director and Revegetation Consultant Glenn Christie. Photo: Greg Mayfield.

PROJECT PROGRESS: Succession Ecology Director and Revegetation Consultant Glenn Christie. Photo: Greg Mayfield.

The ash dam had reached a depth of 5 to 8-metres by the time the plant closed.

While McMahon began moving and spreading topsoil, Christie and his team embarked on the mammoth task of scouring the state's arid zones for a variety of potential seeds.

Following a gruelling seven-month harvest, the team picked a staggering six-tonnes of native seeds consisting of mostly saltbush varieties and samphire.

"We knew from the sites we collected from that the plants were tough and resilient and we knew that we were going to have a very tough site to work on," Christie said.

"It was very interesting to be on the ash before the topsoil cover was applied. I have been doing this for 30 years and I have never seen a site where there was no weeds. It was tough.

"What we were after was colonisers, or pioneer species, what would actually be the first things to come back in a salt marsh if there had been a big disturbance like a fire, flood or something that would scalp the site."

The Succession Ecology team experienced first hand just how resilient some of these plant species could be.

In the following 24 months Port Augusta experienced only half of it's long-term average rainfall, devastating initial efforts.

"Welcome to Port Augusta - that's my phrase," Christie said.

"It started to rain quite nicely in June last year and then the rain just dried out and just to add insult to industry there were the most fierce temperatures.

"If you don't get rain and then the temperatures go ballistic things tend to fry so we had a really good situation this time last year, then the rain follow up didn't come and then the temperatures got nasty.

"A lot of things fried, so we are unfortunately almost back to where we were in May last year."

Significant falls of over 20mm in June alone have put revegetation plans back on track.

"I don't think we will ever be happy until it's covered," Christie said.

"But my wife is an ecologist and she was one of a number of ecologists doing the plant count literally last week, and they have jumped enormously."

Succession Ecology has also been contracted by the Port Augusta City Council to seed Bird Lake, a project that will commence once the lake has dried out and topsoil has been applied.