Development of the drainage (collapsed) zone

The National Parks Association of NSW has serious concerns regarding the assessment of ground and surface water impacts by Adani’s proposed Carmichael mine.

“Current height estimates for the drainage zones that will form over the proposed underground coal extractions are implausibly low. Our calculations suggest instead that these zones would reach the surface over all of the extractions, resulting in full depressurisation and relatively rapid water loss from the mine through to the surface”, says NPA spokesperson Dr Peter Turner.

“The risk to the ancient and very vulnerable Doongmabulla springs complex and the watercourses running over the mining area would be greater than has been suggested”.

The drainage zone is a zone of connected fractures that forms over an underground coal extraction, through which water drains relatively freely and quickly towards to the mine. The zone is unable to hold water. The likely height of the drainage zone is a critical factor in modelling and predictively assessing the likely impacts of underground mining proposals on water resources.

Advice provided to Adani and the Queensland land Court has suggested the drainage zone would reach the surface for up to 42% of the proposed extractions.[1][2] NPA’s calculations suggest this will likely occur for 100% of the extractions.

NPA spokesperson, Dr Peter Turner points to disturbing similarities to the Dendrobium mine in the heart of Sydney’s drinking water catchment. Similar concerns raised by the NPA in 2015 prompted[3] investigations and reviews commissioned by the NSW Department of Planning that found the impacts were much greater than predicted.[4]–[7] The impacts are consistent with the drainage zone reaching the surface.

“Approving the Carmichael mine without first revising the groundwater modelling and reassessing the risks could prove to be a grave mistake.”
 
ENDS.
 
Detailed figures and more information available on request. 

NPA media contact: Dr Peter Turner
 

References

[1]       N. P. Merrick, ‘Adani – Carmichael Coal Project: Assessment of Fracturing in the Groundwater Model’, Heritage Computing trading as HydroSimulations, Advice to Adani Mining Pty Ltd HC2014/33, Dec. 2014.
[2]       N. P. Merrick, ‘Expert Report to the Land Court by Dr Noel Patrick Merrick: Land Services of Coast and Country Inc. v Adani Mining Pty Ltd’, HC2015/6, Feb. 2015.
[3]       P. Hannam, ‘BHP’s coal mine approved in Sydney’s catchment without groundwater assessment’,Sydney Morning Herald, 31-Jul-2015.
[4]       NSW Department of Planning, ‘Mining Impacts at Dendrobium Coal Mine Area 3B’, Report to Government, Dec. 2015.
[5]       T. Sullivan and G. Swarbrick, ‘Height of Cracking – Dendrobium area 3B’, Pells Sullivan and Meynink (PSM), Prepared for the NSW Department of Planning PSM3021-002R, Mar. 2017.
[6]       J. Galvin, ‘Review of PSM Report on Height of Fracturing – Dendrobium Area 3B’, Galvin & Associates, Prepared for NSW Department of Planning, Feb. 2017.
[7]       C. Mackie, ‘Height of fracturing at Dendrobium Mine – Peer review of PSM report’, Mackie Environmental Research Pty. Ltd, Prepared for NSW Department of Planning 906/17, Feb. 2017.

This site uses Akismet to reduce spam. Learn how your comment data is processed.