4. Upper Mundic Gully TSF Description
4.1. Upper Mundic Gully Location and Catchment Description
The Upper Mundic Gully area within the Mount Morgan Mine is a highly modified landform that has
been subjected to previous waste rock and limited tailings disposal. The topography of the Mount
Morgan Mine has been significantly modified through previous mining activities through the creation of
the OCP, placement of overburden in dumps and deposition of latent tailings into natural gullies. Whilst
originally an underground mining operation, during the 1930s-1950 the mining methodology changed
to open cut methods. This activity significantly influenced site topography and associated hydrological
drainage patterns across the entire site.
Figure 11 displays a photograph taken in 1942, viewed from the west looking to the east showing the
waste rock material placed in the Upper Mundic Gully area. The source of this material was the OCP
as the mine was transitioning from underground to open cut operations. Figure 12 shows the placement
of this waste rock material from a plan view. The waste rock placed to the west of the OCP, referred to
as the Western Dump, acts as a semi-permeable barrier which has artificially created a valley within
what should be the headwaters of the Upper Mundic Creek. Currently water pools in an ephemeral
waterbody at the lowest topographical point of the Upper Mundic Gully and a stormwater diversion
tunnel, that was excavated to the northeast of the Upper Mundic Gully area in the early 1980s, diverts
the ponded water to Dam 8 located to the north east.
Dam 8 is used by Heritage Minerals as a source of construction and processing water. There is no
water quality data available to determine if Dam 8 is “clean”. As seen in Figure 14, portions of the waste
rock dump are exposed and may be providing a source of contamination into the ephemeral pond at
the base of the Upper Mundic Gully catchment. This pond then flows, via the tunnel, into Dam 8.
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Wulguru Technical Services Pty Ltd – Supporting Information Report
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