A flooded outback highway connecting Western Australia and the Northern Territory will likely be closed for another month, with the shire responsible estimating repairs to its road network could cost up to $100 million.
The Great Central Road, a dirt highway that runs 1,126 kilometres from Laverton in WA's northern Goldfields to Yulara near Uluru in the Northern Territory,has been closed since March 5 due to widespread flooding.
The closure has affected production at the Gruyere gold mine, 200km north-east of Laverton, forcing truck drivers to make a 9,200km round trip to deliver essential supplies to the remote site.
At the peak of the flooding, water levels on the road reached 1.1 metres high and supplies had to be flown into the Cosmo Newberry Aboriginal community, 90km north of Laverton.
Shire of Laverton chief executive Phil Marshallsaid the Great Central Road would likely remain closed until late May.
"We have people [from the Ngaanyatjarra Lands in the north] trapped in Laverton and Kalgoorlie who want to get home," he said.
"We're working hard on it and as soon as we can open the road, we'll certainly get that open."
Damage to the Great Central Road is just the tip of the iceberg for theShire of Laverton, which manages more than 4,300km of unsealed roads.
Mr Marshall said engineers had assessed about 30 per cent of the network so far.
"Overall we think the damage will range anywhere from $20 million to $100 million," he said.
"Until we get the final figures and our assessment has been completed we're not going to be quite sure, but it's going to be somewhere in that ballpark."
Gold miner reroutes supplies
The Gruyere mine recorded about 140 millimetres of rain in the fortnight to March 14 — equivalent to half its average annual rainfall —and had more significant rainfall on March 19 and March 28.
The floods forced the temporary shutdown of the Gruyere gold mine'sprocessing plant due to a lack of consumables, and open pit mining was also briefly suspended due to fuel shortages.
Gold Road Resources, which owns 50 per cent of the Gruyere mine alongside South African mining giant Gold Fields, reported its latest production results to the ASX on Friday.
Gruyere's production fell from 74,659 ounces in the December quarter to 64,323oz in the March quarter, with the cost of production rising from $1,973 an ounce to $2,194/oz.
Gold Road Resources managing director Duncan Gibbs said supply runs out of Perth had been rerouted via South Australia and the Northern Territory.
It is the same route being taken by trucks re-supplying communities in the remote Ngaanyatjarra Lands.
"That might sound easy but it's been quite a herculean task, requiring a round trip from Perth of more than 9,000km," Mr Gibbs said.
"Google Maps tells me that's more than 100 hours of driving.
"Most of our our vendors simply don't have the trucking capacity and the personnel to do that, so we've also reached out to numerous alternative vendors across eastern Australia."
When asked how much production costs were likely to increase while the road remained closed,Mr Gibbs said he was unsure,
"Look at this point in time, I really don't have numbers on that," he said.
"Obviously, there are some higher transport costs but clearly, it's the right thing to do relative to not operating.
"We're also likely to incur some one-off costs, potentially a few million dollars, that we'll be contributing to reinstate access along the Great Central Road."
Disaster relief funding promised
Laverton was one of eight local governments which this week became eligible for disaster assistancethrough the jointly funded Commonwealth-State Disaster Recovery FundingArrangements (DRFA).
The Shires of Coolgardie, Dundas, Leonora, Menzies, Ngaanyatjarraku and the City of Kalgoorlie-Boulder are also eligible.
Significant repairs will need to be conducted along the Trans Access Road, which runs east from Kalgoorlie-Boulder alongside the Trans Australian Railway Line and is a lifeline for pastoralists on the Nullarbor who have been hit hard by flooding.
Federal Minister for Emergency Management Murray Watt said the funding would help communities and individuals affected by the extreme weather to get back on their feet.
"Shires will be provided with support to undertake emergency recovery and repair works to bring essential public assets like bridges and roads back to usable condition," Minister Watt said in a statement.
"This funding is an investment in the communities and the local economy, to help residents to recover faster."
