56 Boffa Miskell Ltd | Waihi North Project | Terrestrial Ecology Values and Effects of the WUG | 22 June 2022 6.4.2 Effects Associated with Vent Raise Construction and Temporary Habitat Loss This section assesses the effects of the vegetation clearance, site preparation and temporary occupation of the vent raise footprints for the duration of mining. Vegetation clearance for two of the proposed four vent raises may be consented through a separate application. However, the temporary (for the duration of mining) loss of habitat within the footprint of four vent raises is assessed below. The proposed offset for this habitat loss is described in Section 8.5.2. Removal of intact native forest for the construction of up to four ventilation raises is one of the primary ecological impacts of the Project. The final surface expression of each shaft will be approximately 10 x 15 m (150 m2, or 600 m2 combined). For context, Coromandel Forest Park encompasses approximately 72,000 ha of similar forest communities and habitats, and localised disturbances at a similar scale occur periodically in the forest environment as a result of slips, tree falls, and human activity associated with recreational access etc. The location of the ventilation raise sites (Shafts 2-5) will be determined following ecological surveys to assess the presence of native fauna and describe vegetation characteristics (rarity, diversity and size/age) with the objective of minimising ecological impacts. The criteria proposed to avoid / minimise effects are set out in the proposed consent condition 127 for this Project. Conditions for the establishment of a vent raise are provided in Part E of the AEE, (Mitchell Daysh, 2022). In some areas it may be possible to re-use previously disturbed sites (this will require engineering / geotechnical investigations) if this is agreed with the Department of Conservation that manages the land on behalf of the Crown. At present, these sites are still actively maintained as drill sites and are fenced to exclude fauna as well as being regularly re-surveyed to ensure animals have not moved back into them. Re-using old sites would generally be preferable to clearing new sites because it would reduce the quantity of vegetation clearance and would likely minimise impacts on fauna as they may be less likely to occupy a disturbed site. If it is not possible to re-use old sites, the preference of the project team is to site the development areas in the legal road reserve (paper road). Vegetation Communities It is likely that clearance of small areas of forest will cause temporary (albeit prolonged) changes to the forest structure and species composition in the immediate environs due to “edge effect” factors, including increased light (due to removal of canopy species) and changes to temperature, humidity and air movement within the surrounding forest. However, the extent of clearance is comparable to the disturbance associated with a slip or large tree fall, and the sites are likely to be readily colonised by native species. Low stature, early successional vegetation (e.g. sedges and kiekie) have been observed in old drill sites and were found to be occupied by Archey’s frogs (Hotham 2019). Remediation of the site would include returning woody material and fern stumps to the footprint area and management of weeds. The extent of vegetation clearance required for the Project is small in the context of the surrounding area (i.e. maximum of 0.0576 ha in 71,899 ha) land area of Coromandel Forest Park), and given the widespread extent of the forest type (mature broadleaf forest) to be removed. The clearance area would be smaller still if old drill sites are reused, although the temporary loss of habitat area would be the same. The magnitude of effect of delayed forest regeneration is small in the context of the surrounding area and is assessed as Low. The ecological value of the vegetation communities is Very High
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