3
Record of site visit
A site inspection of Upper Mundic Gully was undertaken by Damien Tol (WSP) on 24 July 2024 who was escorted around site by Dennis (Heritage).
3.1 Purpose of visit
The purpose of the visit was to:
— Inspect the general layout of Upper Mundic Gully including: — Condition of the potential TSF abutments — Extents of the mine spoil dump — Visually assess natural ground conditions — Assess the condition of the stormwater tunnel.
3.2 Weather
The weather at the time of the inspection was fine, with temperatures between 17 and 22.6°C. No rainfall had been recorded at the Rockhampton weather station (approximately 36 km from site) in the two weeks prior to the site visit 1 .
3.3 Observations
The following observations were made onsite with reference to selected photos presented in Appendix B.
— Upper Mundic Gully is heavily vegetated with large trees growing in the base of the gully — A small pump has been installed in the gully to dewater below the inlet of the stormwater diversion tunnel – the pump outlet pipe passes through the stormwater diversion tunnel — The stormwater diversion tunnel appears to be excavated through high strength igneous rock at the portals at both ends, transitioning to a sedimentary rock in the central portion of the tunnel – rock at the portals appears moderately weathered with some large defects — The stormwater diversion tunnel is generally unobstructed – some branches and erosion of the floor near the inlet, with evidence of rockfall towards the middle (beyond the concrete inlet) — Access to Upper Mundic Gully is limited to single lane LV access tracks – considerations to construction accessibility will be required — The proposed TSF abutments are heavily vegetated however exposed sections indicate the underlying material is primarily moderately to highly weathered rock — The proposed TSF abutments are very steep (approximately 1V:1.25H) – consideration of constructability for the embankment and tie ins will be required — Large boulders (>1 m diameter) were observed on the mine spoil dump batters.
1 http://www.bom.gov.au/climate/dwo/202407/html/IDCJDW4102.202407.shtml accessed 21 August.
Project No PS213278 Upper Mundic Gully TSF Concept Design to RL 390 m Mount Morgan Project Heritage Minerals
WSP October 2025 Page 4
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