Appendix C - Cultural Heritage Impact Assessment - Peabody Energy

Cultural Heritage Impact Assessment
North Wambo Underground Mine Modification
While impacts to archaeological and cultural heritage within the MA are predicted to be negligible to low
(MSEC 2012), it is recommended that, if required, Wambo Coal seek an AHIP under Section 90 of the NSW
National Parks and Wildlife Act, 1974 (NPW Act) to allow for subsidence movements and the salvage of
registered and unregistered sites (should they be uncovered) in consultation with the relevant Aboriginal
parties. If salvage is required it is recommended that artefacts be transferred to the temporary keeping place
under the existing Care and Control Permit (#3130) in consultation with the relevant Aboriginal parties.
Subsidence estimates for the project area (including specific predictions for Aboriginal sites) have been
provided by MSEC (2012). Much of the surrounding area has also been previously undermined (Wollemi
and Homestead workings in the Whybrow Seam), or approved to be undermined, including NWUM in the
Wambo Seam, the Arrowfield and the Bowfield Seams.
The NWUMM longwall area will be subject to a Subsidence Management Plan or Extraction Plan which will
be implemented prior to the proposed works being undertaken.
MSEC (2012:58-60) calculated the maximum predicted total conventional subsidence parameters for the
archaeological sites in the MA for approved mining of the Wambo, Arrowfield and Bowfield Seams (Approved
Layout) and compared them to the predicted values for the proposed NWUMM (Modified Layout). The
predicted maximum incremental changes in subsidence resulting from the proposed modification at any
Aboriginal site ranged from 0mm to 2400mm; in tilt ranged from 0mm/m to 35 mm/m; in hogging curvature
ranged from 0 km -1 to 1.50 km -1 ; and in sagging curvature ranged from 0 km -1 to 1.90 km -1 (MSEC [2012:58-
60, Table D01]). Further MSEC (2012: Table D01) predicted that although the maximum subsidence effects
in the vicinity of known Aboriginal sites resulting from subsidence relating to the Modified Layout could vary
between 350 mm and 6400 mm (35 cm and 640 cm) the actual incremental change between the Modified
Layout and the previously Approved Layout varied between 0 mm and 2400 mm (0 cm and 240 cm). This
increment would be an even smaller proportion of approved subsidence impacts if the historic workings
(Whybrow Seam) were also included in the subsidence model.
As such, MSEC (2012) predicted that the subsidence effects in the vicinity of known Aboriginal sites would
not exceed 2400 mm and was significantly lower for the majority of Aboriginal sites ranging from 0 mm to
2400 mm (0 cm to 240 cm). MSEC (2012:59) considered that the artefact sites in the MA could potentially
be affected by cracking of the surface soils. It is unlikely that the Aboriginal objects at these sites would be
destroyed by the surface cracking but could be impacted on or harmed by downward movement due to
vertical subsidence (whereby the land surface moves downwards as a whole). However, compared to the
existing and approved mining in this area, the NWUMM would not increase the risk of impacts to these sites.
The Wollemi National Park escarpment cliff lines and steep talus slopes are more than one kilometre from
the NWUMM area and are outside of the predicted subsidence impact area (MSEC 2012). As such, the
proposed modification will not impact on the Wollemi National Park or the associated escarpment. Wollombi
Brook lies approximately 500 m to the east of the project area and 1 km from any Aboriginal sites within the
NWUMM area. Wollombi Brook will not be impacted by the proposed NWUMM (MSEC 2012).
The existing Consent #2222 (Consent to Destroy with Salvage) covers the vast majority of the MA. It is
therefore recommended that either the existing Consent be slightly expended or a new AHIP be applied for
to cover the southern extent of the MA.
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