A former WaterNSW hydrogeologist has discovered rock beneath Woronora Reservoir south of Sydney is cracking in “unrecognised” methods due to continued coal mining.
Key factors:
- The Nature Conservation Council is asking for operations at Metropolitan Coal Mine to be halted whereas the findings of the report it commissioned are reviewed
- Peabody says the claims of environmental impacts from its operations have been thought-about by authorities authorities and specialists many occasions throughout a few years
- The previous WaterNSW hydrogeologist who performed the evaluation says he’s “fairly alarmed” by the findings
In work commissioned by the Nature Conservation Council (NCC), Peter Dupen reviewed the environmental efficiency of Metropolitan Mine at Helensburgh towards its planning approval.
His report describes an “unrecognised” subsidence affect within the catchment.
“What I am now saying is the model of the affect is new,” Mr Dupen mentioned.
“It wasn’t predicted on the time the coal mine was being authorised and it hasn’t been actually correctly reported.
“It might be a really main change within the skill of those reservoirs to provide high-quality ingesting water to higher Sydney.”
Owned by Peabody, Metropolitan Mine extracts coal from the Bulli seam utilizing underground longwall mining in and across the restricted Woronora particular space, together with beneath Woronora Reservoir.
In 2017, floor water impacts across the japanese tributary above the mine had been reviewed as a part of the Independent Expert Panel for Mining in the Catchment report.
It really useful “extra monitoring be undertaken in the direction of the Woronora Reservoir and the set up of extra inclinometers within the higher sections of the overburden for detecting any vital shear airplane motion extending in the direction of the reservoir”.
The panel report discovered it didn’t have “any agency view on whether or not the safety of water storage in Woronora Reservoir may very well be unacceptably impacted by basal shear planes”, however it discovered “the probability of unacceptable leakage into the mine may be very low”.
Basal shear airplane formation is a time period for a fracture in rocks on the backside of a valley the place steep terrain has been undermined.
Mr Dupen mentioned his analysis discovered proof of the brand new fractures based mostly on a kilometre-long dry stretch of the japanese tributary.
“It has grow to be clear to me that there’s widespread opening of basal shear planes and, as soon as they’re open, they’re virtually actually by no means going to shut once more,” he mentioned.
Impression on water high quality
Mr Dupen mentioned water that might have in any other case run down the perimeters of the ridges and alongside the creek was now being diverted into the rock vertically and transferring into the centre of the valley.
“It means the rainfall that falls into the catchment is now not working alongside the floor or soils,” he mentioned.
This meant the the water wouldn’t be filtered as successfully as a result of it was taking a unique course.
“That’s what the entire thought of those particular areas has been the vegetation cleanses and filters the water,” Mr Dupen mentioned.
He mentioned the findings didn’t counsel a considerable discount in water getting into the reservoir.
However he mentioned water high quality may impacted and was “fairly alarmed by it”.
The NCC really useful that mining beneath the reservoir be stopped instantly till the implications had been reviewed.
Launched simply earlier than election
A spokesperson for Peabody identified the analysis paper had been commissioned and paid for by the NSW NCC and launched within the ultimate days of the state election marketing campaign.
They mentioned Mr Dupen’s claims of environmental impacts had “been thought-about by authorities authorities and unbiased specialists many occasions throughout a few years”.
“His theories have been investigated by two earlier unbiased scientific panels, the NSW authorities’s personal Impartial Knowledgeable Panel into Mining within the Catchment, and the Woronora Reservoir Impression Research,” the spokesperson mentioned.
“The six eminent scientists on the NSW Impartial Knowledgeable Panel concluded that the operations of the Metropolitan Colliery had been having a negligible affect on the standard and amount of water reaching the Woronora Reservoir, two of a very powerful points for native residents.”
A Division of Planning and Surroundings spokesperson mentioned because of a 2017 investigation into impacts of mining on the japanese tributary, the mine operators had been ordered to arrange and implement a remediation plan.
The work is because of be full by 2024.
“Now we have not acquired any experiences relating to any sub-horizontal airplane actions, and we encourage the Nature Conservation Council to share its evaluation with us,” the spokesperson mentioned.
“If anybody has considerations on potential breaches relating to any state vital growth, we urge them to contact us.”
