What do we know about the new Dendrobium Mine Extension proposal?

Information is taken from South32’s Scoping Report on the DPIE Major Projects website

  • South32 is seeking to extend into “Area 5” — the plan to mine “Area 6” has been abandoned
  • The proposal seeks to extend the life of the mine until 2041 (previously 2048)
  • South32 have redesigned the proposal to try and address concerns about impacts to the water catchment
  • Longwall width appears unchanged — previously proposed as 305 metres wide, with narrower longwalls identified as far less destructive but uneconomical for the mine
  • South32 will continue to undermine streams, upland swamps, and identified Aboriginal cultural heritage sites

While it is clearly undemocratic that this project has been given SSI status following clear opposition from the local and scientific communities, it is obvious that this has had a significant impact on this revised proposal.

The initial detail of these amendments to the proposal are as below — taken directly from the Scoping Report:

• approximately 60% reduction in longwall mining area;

• approximately 60% reduction in surface water losses (from the previous application);

• no predicted connective fracturing from the seam-to-surface when using the Tammetta equation;

• no longwall mining beneath 3rd, 4th and 5th order (or above) streams;

• approximately 50% reduction in the length of 1st and 2nd order streams longwall mined beneath;

• approximately 40% reduction in the number of swamps (listed as threatened) longwall mined beneath;   

• commitment to avoid longwall mining beneath identified key stream features;   

• reduction in number of previously identified Aboriginal heritage sites directly mined under from 22 to six sites (with the likelihood of direct impacts to these six sites expected to be approximately 1 in 10 based on extensive monitoring of subsidence-related impacts to heritage sites);   

• no longwall mining beneath previously identified high archaeological significance Aboriginal heritage sites;   

• increased longwall mining setback distance (at least 400 m) from the Avon River, Cordeaux River and Donalds Castle Creek;   

• minimum longwall mining setback distance of 300 m from the Full Supply Level of the Avon Dam;

• minimum longwall mining setback distance of 1,000 m from dam walls; and       

• use of existing infrastructure (namely the Dendrobium Pit Top, Kemira Valley Coal Loading Facility, Kemira Valley Rail Line, Dendrobium CPP, Shaft Sites Nos 1, 2 and 3 and the West Cliff Stage 3 Coal Wash Emplacement) which would reduce the requirement for additional disturbance