U:\2021\BM210482_IBo_Waihi_North_Project\Documents\WNP_Freshwater_Report_May_2022\FINAL_Freshwater_Report_FOR DELIVERY_June 2022\FINAL DELIVERED 17 JUNE 2022\WAI-985-000-REP-LC-0007_Rev0_Freshwater_20220621_FINAL.docx 7.0 Wharekirauponga Underground Mine 7.1 Introduction The Wharekirauponga orebody is located approximately 11 km north of the township of Waihi. The resource lies beneath the CFP within the Wharekirauponga Minerals Mining Permit (60541) area. OGNZL is proposing to construct an access tunnel system to undertake further exploration and subsequent mining of the Wharekirauponga resource. The project will comprise surface infrastructure on farmland at Willows Road, a rock stack for overburden, tunnel portals, a tunnelling system, ventilation raises and the mine itself (Figure 4). 7.2 Wharekirauponga Project Activities 7.2.1 Background The WUG Project Site has two components: the landholding owned by OGNZL and currently in use as a farm where the portal entrance and associated surface infrastructure will be constructed (Willows Road Farm); and up to four small and discrete sites within the Wharekirauponga Stream catchment on unformed HDC road reserve in CFP where the ventilation raises and egress shaft will be located. The Willows Road Farm comprises 197 ha of primarily pastural land located approximately 5 kilometres north of the Waihi township. The site is accessed off SH25 at the foothills of the Coromandel Ranges. The wetland and freshwater assessment pertain to the Willows Farm Road location and WUG. 7.2.2 Water Management Proposed water management includes erosion and sediment control ponds located within the development to reduce sediment laden water from entering into the Mataura Stream. Initially, contact water from the tunnel and rock stack will be collected in the collection pond before being pumped via a dedicated pipeline located in the services trench to the existing WTP for processing and subsequent reuse/discharge in accordance with the consent conditions that apply to that discharge. Several other small ponds will be constructed across the site to intercept run-off water to allow solids to settle prior to return to Mataura Stream. These ponds will be designed to accommodate silt removal as required, with silt periodically removed and transported back the TSF decant ponds for disposal. 7.2.3 Rock Stack The design of the rock stack incorporates dish drains around the stockpile that separate catchment water from rock stack contact water. Catchment water will be diverted around the rock stack via clean water diversions to maintain flows in the lower reaches of tributary 2. On exhausting of the rock from the rock stack, tributary 2 will be rehabilitated and returned largely to its original configuration, with improved riparian areas and stock exclusion fencing to protect the waterway.
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