Sydney's water supply under threat from BHP Long wall coal mine extension

"Allowing BHP to undermine our drinking water supply defies common sense and breaches a personal commitment by Premier O'Farrell to prevent mining in drinking water catchments," Nature Conservation Council of NSW Chief Executive Officer Pepe Clarke declared on Tuesday with the announcement that approval had been given to BHP Billiton's Mount Kembla Dendrobium coal mine to extend under part of Sydney's water catchment.

On Monday 11 February the New South Wales State Government Department of Planning and Infrastructure gave approval to BHP Billiton's Mount Kembla Dendrobium Area 3B long wall mine extension plan. This involves several underground excavations directly under Sydney's Woronora water catchments. The approval was strongly criticised by conservationists including Total Enviropnment Centre director Jeff Angel, and the NSW Conservation Council Pepe Clark who accused the Premier Barrie O'Farrell of breaking a key pre-election promise of not to mine in Sydney's catchments.

Related: Longwall mining, subsidence and damage to Sydney waterways and wetlands | Aboriginal Heritage: Water - Everyone's Future | SMH: Mine approved despite water catchment fears

In 2010 a similar plan received a scathing report from the NSW Planning Assessment Commission which highlighted that such mining in publicly owned water catchments and under swamps was no longer acceptable to the community.

BHP's Dendrobium Mine employs 400 workers and supplies high quality coking coal to the Port Kembla and Whyalla steelworks and for export. The mine operates on a continuous basis, 24 hours a day and 7 days a week. The mining operations are located approximately 8km west of Wollongong, adjacent to Mt Kembla. Dendrobium is approved to produce up to 5.2 million tonnes of coking coal per annum with an expected mine life in excess of 20 years.

In a media release Jeff Angel from the Total Environment centre said;

"The Planning Department has approved 300m wide mining voids right under a significant cluster of endangered swamps with guaranteed subsidence and inevitable damage to Sydney's water supply,"

"The area in question is known to be the most ecologically sensitive in the entire Dendrobium lease but the Government has caved into BHP Billiton's manipulation of the planning process. BHPB was given a 10 year environmental warning about this important area; but it did nothing, waiting till the last moment to force the government's hand."

"In previous inquiries the company has admitted that it doesn't know how to remediate swamps and the Department admits there will be damage - yet somehow BHPB has gained approval for one of the most aggressive mine plans possible."

"Water security is vital to a growing city. The damage predicted by BHP Billiton's own consultants will make it very difficult for the Sydney Catchment Authority to uphold its legislated responsibility to protect the catchments."

"There are other imminent mine proposals in Sydney's water catchment and another on the Central Coast. The Premier must explain how he intends to protect water supply catchments as a matter of urgency," concluded Mr Angel.

Underground mining will threaten swamps and wetlands that provide essential water filtering services to maintain the quality of Sydney's water. The wetlands are also endangered ecological communities that will be lost if the water is drained due to underground longwall mining.

Mining under Sydney's catchments has been a political issue for several years. In 2008 deep fractures a metre wide were discovered in the water supply catchment above BHP-Billiton's Dendrobium mine.

"The proposed long-walls are more than 300m wide and will cause severe subsidence and significant cracking that will very likely drain up to 12 upland swamps," Mr Clarke said. "These swamps are endangered ecological communities and provide a reliable supply of water, especially during long dry spells.

"The O'Farrell Government has bowed to pressure from the powerful mining lobby by putting the short-term financial interests of BHP above all other considerations. This is an appalling decision for the environment and the long-term viability of Sydney's water supply, especially in the face of climate change."

Although mining has been approved conditional that BHP remediate drained swamps, any ecologist will tell you the difficulty in restablishing wetland swamps in areas suffering subsidence. The Office of Environment and Heritage warned in its submission that: "there are no accepted measures available for the successful remediation of impacts to cracking of bedrock supporting upland swamps".

"This decision is a betrayal of the trust that people place in government to protect our environmental heritage and water supply from harm," Mr Clarke concluded.

Sources:

• Total Environment Centre media release 12 February 2013 - BHP Billiton mine plan gets go ahead to damage Sydney's water supply catchment
  
• NSW Conservation Council media release 12 February 2013 - BHP mine approval breaks Premier's promise, threatens Sydney's water supply
  
• Image from Climate Camp NSW / Flickr (2009) - Activists lock on to Dendrobium coal mine - Creative Commons Attribution 2.0 Generic (CC BY 2.0)