SUSAN Lawrence had been studying the goldfields for 30 years when she discovered something which had entirely changed the face of Victoria.
Sludge. Billions and millions of cubic litres of mud, polluted mining waste, that overflowed from the rivers, poisoning farmland and completely changing the landscape.
It's a phenomenon that's been almost completely forgotten, but forms the basis of Professor Lawrence and co-author Peter Davies' new book Sludge.
As archaeologists, Professor Lawrence and Dr Davies struck by fragmentary channels they saw in the field, built to carry water on the mining sites. So they followed them. What they found was the first industrial use of water in Australia on a large scale.
Going through the archives, they developed maps of all the old channels and found huge amounts of capital investment going into water. Vast fortunes were being made buying and selling it.
But then they started to wonder what happened to it next. They began to realise that the water became extremely polluted being used in the mines, but it was just released back into the nearest waterway.
"We started to wonder, 'Surely people must have complained about this?'," Professor Lawrence said.
And complain they had. Professor Lawrence and Dr Davies found "an enormous amount of documentary evidence" of people despairing the sludge.
It choked up rivers, filled waterholes, and overflowed rivers banks. The waste covered farmland, sometimes at depths of six to 10 feet.
Professor Lawrence and Dr Davies have begun a project to investigate whether the polluted sludge has had long term effects on the landscape.
Sludge is just one of the incredible changes to the goldfields since the gold rush, Professor Lawrence said.
Miners felled the trees to use as timber and pit props underground, meaning many of the forests around Bendigo are regrowth.
And the mining changed the rivers. Originally waterways would have been made up of deep waterholes, interspersed with chains of ponds, Professor Lawrence said.
In rainy periods, these would have flooded to form a river, while in dry the waterholes would have kept water.
With Victorian gold mines booming again, mining is a hot topic again.
"Bendigo's having a gold rush now. It's quite a current issue, and so it's quite interesting and important to think about what the benefits about mining, but what are the costs as well," Professor Lawrence said.
"What are the lessons we need to learn about how we handle mining?"
Sludge will be launched at the Bendigo Writers Festival.
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