Supporting Technical Assessments

EGL Ref: 9049 23 June 2022 Page 35 File: WAI-985-000-REP-LC-0050-Rev0.docx This report shall only be read in its entirety. the new settlement markers in areas where there are residential dwellings or other structures not owned by OGNZL. • Recommended additional settlement monitoring markers and piezometers to measure potential settlement effects are summarised below and in Figure 66 to Figure 69: o Potential dewatering of the Gladstone vein south of GOP ▪ Heath Road – Additional settlement points (Figure 67) ▪ Clarke Street – Additional settlement points (Figure 67) o Additional settlement monitoring points around Gladstone Hill to provide an understanding of the settlement effects close to the pit. o Potential dewatering of the ignimbrite between the Wharekirauponga Access Tunnel decline and Boyd and Barry Road. ▪ Boyd Road – Additional settlement points (Figure 68) o Potential additional dewatering of the andesite rock due to the proposed MUG decline in andesite beneath Moore Street. ▪ Moore Street – Additional settlement points and a new piezometer borehole (Figure 67) o Potential dewatering of the andesite veins and rock mass not already dewatered by the development of the Wharekirauponga Access Tunnel east of Waihi East. ▪ Barry Road – A new piezometer borehole adjacent to the houses in the tunnel corridor (Figure 68) ▪ Mataura Road – Additional settlement points and a new piezometer borehole in the tunnel corridor (Figure 68) ▪ Wenlock Street – Additional settlement points and a new piezometer borehole in the tunnel corridor (Figure 68) ▪ State Highway 25 – Additional settlement points and a new piezometer borehole in the tunnel corridor (Figure 68) ▪ Wharry Road – Additional settlement points and a new piezometer borehole in the tunnel corridor (Figure 68) • Extension of the town settlement monitoring points out to the end of Willows Road, Highland Road, and Reservoir Road to cover the project extent near structures. (Figure 69) 9.0 CONCLUSIONS EGL was engaged by OGNZL to assess the ground settlement effects from dewatering for the Waihi North Project. The large number of settlement observations at Waihi, spanning some 32 years, provides a reliable database for estimating likely future settlements associated with further dewatering.

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