Table 6.4 presents the total PAR for each scenario, according to ANCOLD (2012) and Table 6.5 presents the permanent and itinerant PAR for each scenario, according to DETSI (2025). As noted in Section 6.2.1, the latter discounts mine personnel or persons located in an area with inundation depths lower than 0.3 m from the estimates.
Table6.4
PAR estimates (ANCOLD)
PAR
Stage 1
Stage 2
Mining operations
0
45
8 (1)
Township of Mt Morgan
0
Total
<1
53
(1) PAR corresponds to four properties identified within flood extents.
Table6.5
PAR estimates (DETSI)
PAR
Stage 1
Stage 2
Mining operations
0
0
4 (1)
Township of Mt Morgan
0
Total 4 (1) PAR corresponds to only two properties within flood extents impacted by flood depths greater than 300mm. <1
6.2.2 Potential Loss of Life The ANCOLD Guidelines on Risk Assessment (ANCOLD, 2022) recommends the adoption of the Reclamation Consequence Estimation Methodology (RCEM), developed by the U.S. Bureau of Reclamation (USBR) (USBR, 2015), considering it the most suitable for applying to large dams in Australia based on the extensive database, guidance documentation and the industry experience in its application. 6.2.2.1 RCEM approach The RCEM approach is based on empirical interpretation of dam failure and flood case histories from 1903 to 2013. The method relies on the accurate development of PAR values and the assessment of key factors such as: time to arrival (or warning time), time to flood peak, and the product of peak flood depth and peak velocity (also referred to flood severity). A series of curves have been fitted to case histories that relate the DV product to a fatality rate in terms of the percentage of the PAR with little or no warning, partial warning, and adequate warning. The fatality rate estimation developed by USBR (USBR, 2015) was based on 80 case history data points for water floods.
Project No PS213278 Upper Mundic Gully TSF Stage 1 and 2 DBA and CCA Mount Morgan Gold Mine Heritage Minerals
WSP May 2026 Page 27
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