The Berejiklian government has given the nod for the extension of coal mining under one of Greater Sydney’s reservoirs, the first such approval in two decades.
The Planning Department earlier this month told Peabody Energy it could proceed with the extraction of coal from three new longwalls, two of which will go beneath Woronora reservoir.
Planning Department official Mike Young says in a letter dated March 16 to Metropolitan mine that as the longwall will be the first to go under the reservoir it was important the extraction plan was “sufficiently robust” with “an appropriate adaptive management regime” to limit the impact of subsidence on water supply.
The letter details conditions for the miner, which include regular reviews of monitoring data and monthly reports to Planning and WaterNSW. National Parks Association mining projects science officer Peter Turner said the last time one of Sydney’s storages was undermined by coal operations was the Cataract reservoir in about 2000.
Subsidence caused by the collapsing rock after coal has been removed can create cracks that reach the surface and can drain water elsewhere. The subsidence can continue 25 years after the mining, he said.