Landslides triggered by Tropical Cyclone Jasper have affected the chemical composition of a flood-hit community’s water, creating a $150 million (US$97.55 million) problem.
More than two months after Jasper hit far north Queensland, the Douglas Shire region north of Cairns is still counting the cost.
Massive landslips remain on some roads in a blow to the lucrative tourism industry, with 10,000 cubic metres of dirt at risk of crashing down “at any time”.
The water supply is another major casualty of landslides after record flooding caused by Jasper.
Both filtration plants need to be replaced, putting the community at risk of a water shortage.
“The amount of big landslides that landed into our water system, the water has actually changed its chemical composition,” Douglas Shire Mayor Michael Kerr told AAP.
“It is no longer the same water we used to have.
“That’s causing a really big problem - both our filtration plants are no longer fit for purpose.”
State and federal specialists are working on short and long term solutions and how they could be funded.
“It’s not going to be an easy task,” Mr. Kerr said.
“The figure we have been given to get our water back up to a perfect solution is around the $150 million mark.”
Since Jasper hit, the shire’s water treatment plants’ filters block more quickly.
When it rains, the problem gets worse.
And it rains a lot in the Douglas Shire.
Mr. Kerr said there were about two days’ worth of water supply in their reservoirs at Port Douglas and Wonga, ensuring extended delays to fixing a filter led to shortages.
“When the rain falls the water speed intensifies, starts stirring up the debris in the water and by the time we get to the intake it is quite sludgy,” he said.
“The plant can’t process it so we have to turn the plant off, rely on the small reservoirs we have got.
“If we have a long period of rain ... and the plant is offline for more than two days that’s when you start running out of water which is what happened last week.”
Mr Kerr said they needed to not only replace their two filtration systems but add backup tanks.
“The whole package of getting everything done to ensure we have sustainable water will take a couple of years,” he said.
Then there’s the roads.
More showers have ensured a landslide on the Alexandra Range has still not been addressed.
“You can’t start digging around there while it is raining, those slides are still moving,” Mr. Kerr said.
“The engineers we have spoken to said we need to put in 20m to 30m support poles in the ground to be able to hold the road up where it is collapsing,” Mr. Kerr said.
“The other alternative is to go outside the road reserve and into the wet tropics areas - that is going to cause problems as well.
“There is no easy solution to that one.”
They are still assessing the risk posed by a Thornton Range landslide.
“The geotechs are saying there is around 10,000 cubic metres worth of dirt that could come crashing down at any time,” Mr. Kerr said.
The road is not expected to be available for tourist access for another six months.
“We still have to get through our wet season yet - it is only just starting,” Mr. Kerr said.
