Petition to the Legislative Assembly of NSW – please stop mining under Woronora Dam

In-principle approval has been given for at least 10 longwall mines which are expected to pass below Woronora Reservoir.

In March 2020, in the midst of heightened public anxiety about the coronavirus, Planning Minister Rob Stokes quietly granted final approval for three of these mines to go ahead – LWs 305, 306, and 307. LW306 and LW307, will run directly under the reservoir.

Over 10,700 people have signed a petition calling for this mining to be stopped.

The petition was submitted to State parliament in February 2020. Under state legislation, petitions with more than 10,000 signatures are required to be debated in State parliament – and the debate was set down for 26 March.

Parliament was suspended that week and the debate was cancelled. Meanwhile, approval for the mines beneath the reservoir was quietly granted a week prior to when the debate was due to take place.

Water security is a matter that goes beyond politics – no matter what your political leanings or position on coal. Woronora is a critical public asset that is simply too important to jeopardise.

Maintaining the integrity of our water supply is important and should be given public consideration. This has not happened. Meanwhile mining has been declared an ‘essential industry’ and continues uninterrupted, while parliament itself has been suspended.

So many people we’ve spoken to are appalled at what is taking place. Mining under a major water supply makes no sense. A recent freedom of information request found Cataract and Cordeaux dams breached recommended iron levels 90 times in three years due to mining related activity. We do not want that to happen to Woronora.

The photo to the left here is of the Eastern Tributary of the Waratah Rivulet. It was taken in July 2019, and shows heavy iron oxidising bacteria growth and iron oxyhydroxide floc contamination. Water in this area is supposed to be pristine, and the water clean, filtered through natural streams and swamps – the water has changed to this rust colour because it drained underground through cracks caused by subsidence from longwall mining, and has come out again contaminated.

WaterNSW Submission to the Independent Expert Panel for Mining in the Catchment –

“An issue which particularly concerns WaterNSW is that it is anticipated that any additional increases in iron, manganese and possibly aluminum and other species dissolved from undermined catchments will impact on raw water quality delivered to Sydney Water and other customers…metals transported to reservoirs in particulate and/or dissolved forms are more likely to be precipitated and build up in the lake sediments over time.” See p.24

This water all runs directly toward Woronora dam.


The Woronora Dam catchment is classified as a ‘Special Area’ – permission is required to enter. Fines for entering without permission can be up to $44,000.

The photos you see on this page were taken on the few occasions permission was granted. People are not normally allowed into the area in case they cause damage, or pollute the water.

Waratah Rivulet is a significant tributary leading to Woronora dam. The photo here shows a streambed that has cracked due to mining related subsidence – compressive forces have caused “upsidence” where the creek bed bulges. All surface flow has been lost.

(image: Julie Sheppard – for more images please see the POWA – Protect our Water Alliance website)

Cumulative impacts could have serious negative consequences for reservoir water quality

The Wororona ‘Special Area’ is covered with larger rivulets, streams and swamps.  Swamps play a critical role in filtering and purifying our water.  In the mine plan map here, the swamps are depicted in brown.  A recent independent expert panel looking into mining in the catchment has noted that damage to swamps from mining can be irreversible.  Their report states mining should not be allowed on the basis that remediating swamps is possible.   

According to WaterNSW at least two swamps in this area have already dried out due to mining related activity. They have said that mining in the Woronora Special Area catchment has resulted in ‘environmental consequences [that] have caused (or are likely to cause) breaches in conditions in the relevant development consents, including performance criteria to protect watercourses and Sydney’s drinking water catchment.’  They also say ‘that there are numerous deficiencies in the manner that analysis and modelling is currently being used to support mining applications in the catchment.’ See p.3

The independent Expert Panel similarly noted predictions of impacts have proven unreliable. Their final report states that water returning to the surface from mine workings can ‘leach metals’ and this ‘needs increased attention in mining proposals, especially in the Special Areas where ‘cumulative impacts could have serious negative consequences for reservoir water quality‘. See


Pool N

The video below shows ‘pool N’, which was a 150m long permanent pool of water, part of the Waratah Rivulet that flows into Woronora dam. It remained full during the 2006-7 Millennium drought. This video was taken in 2014 when it drained dry due to cracks in the bedrock.

If the water reemerges from these cracks it can be leached through with chemical contaminants including iron, aluminium and manganese, lithium, strontium, barium, titanium, zinc and nickel. Even trace amounts of zinc and nickel are toxic. Whether such contaminants are accumulating on the floor of the Woronora reservoir is unknown.

The Independent Expert Panel report also states there is a limited understanding of the extent to which water is entering old mine workings, and notes the danger of the ‘permanent diversion of catchment water into mine workings.’ The report states this raises the question of the reliability of estimates of how much water is being diverted from the catchment. See p.v

In late July 2019 The Sydney Morning Herald published an article with drone footage showing streams filled with more red and soupy green discoloured water: ‘Shocking’: Mining damage in Sydney’s catchment prompts calls for halt‘. In that article, Peter Turner, mining projects science officer for the National Parks Association, confirmed that: “A lack of pre-mining data, limited monitoring, and inadequate catchment and reservoir water-balance modelling make it essentially impossible to reliably determine how much water was actually being lost.”

In more recent news, mid February 2020 the mining company, Peabody, applied for a new exploration licence, covering  2042 hectares, an additional permit to explore for coal in the Woronora ‘Special Area’ catchment under and around the left arm of the reservoir: “‘Perverse’: Peabody lodges new coal mining bid for Sydney’s catchment“. This would extend mining operations beyond 2030.

Nic Clyde, from Lock the Gate Alliance, said the application to explore within the “sensitive” catchment region was “an insult to all who rely on Sydney’s water supply… Perversely, lodged when the city has only just begun to recover from one of the worst droughts on record, when water supplies dropped to 42 per cent.”


Independent Expert Panel for Mining in the Catchment

The final recommendations in the Independent Expert Panel is report suggest mining in Woronora be allowed to continue subject to increased monitoring.   The original terms of reference for this review focused on identifying how to “strengthen monitoring networks”, and “undertaking further scientific research” – the terms of reference ensured the report focused on monitoring, rather than the question of whether mining should be allowed at all. This made the final recommendations a foregone conclusion.

We do not view continued mining with increased monitoring of increasing damage as a solution.  Once mining induced subsidence cracking to the bedrock occurs it keeps happening – and continue even 20 years after it first occurs – the damage is ongoing, and will get worse over time, even after the mining company has left.

Mining in LW 304 stopped late in 2019 as a result of additional damage that was caused. Sutherland Shire Environment Centre recently sent a submission to the NSW Department of Planning, Industry, and Environment opposing Metropolitan Coal’s Excavation Plans for Longwalls 305-307, which highlighted concerns raised by the Independent Panel Report in relation to ongoing subsidence damage and Peabody’s ‘Adaptive Management’ – this fails to take into account that movement in each successive longwall the compounds the already existing subsidence.  Impacts are ongoing, occur in an incremental manner across longwalls, and the final cumulative impact may take several years to be identified.  Each successive longwall tunnel will be impacted to an unknown extent by effects from previous adjacent longwalls.  


The Water NSW Act 2014 states WaterNSW has a statutory obligation ‘to protect and enhance the quality and quantity of water in declared catchment areas’.

The Woronora Special Area catchment is a critical public asset, part of our water supply infrastructure.  The Act also requires WaterNSW to act ‘in accordance with sound commercial principles’, and ‘to maximise the net worth of the State’s investment’.

Our water supply ‘Special Area’ catchments were set up originally so that if one failed the others could stand in as reserves.  In 1998, extreme rain and flooding filled the drought-affected Warragamba Dam in just a few days. This triggered the Cryptosporidium crisis.  Woronora was not affected.  In 2015 the desalination plant was damaged by a typhoon and took a few years to properly repair.

Our ‘Special area’ catchments are meant to be protected for a reason.


Image: Julie Sheppard –


Members of parliament to contact and ask for assistance to protect our water –

Lee Evans MP Member for Heathcote

Mark Speakman Attorney General and Member for Cronulla

Eleni Petinos MP for Miranda

Rob Stokes Minister for Planning

Matt Kean Minister for the Environment

Melinda Pavey Mister for Water

Jodi McKay MP

Clayton Barr MP, Shadow Minister for Water Member for Cessnock

Kate Washington MP, Shadow Minister for the Environment

Mark Buttigieg Labor Upper House MLC

Adam Searle MLC, Shadow Minister for Resources,

Cate Faehrmann, MLC

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