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 10.0 Tailings Storage Management 10.1 Introduction 10.1.1 Tailings Storage Facility (TSF3) A new Tailings Storage Facility (TSF3) is proposed to provide the tailings storage for the WNP in addition to that provided by the proposed GOP TSF. TSF3 is a downstream earth and rockfill embankment structure, like TSF1A and 2, and forms an impoundment to store the discharged tailings slurry pumped from the Processing Plant. The total footprint of TSF3 is approximately 115 ha. Of this area 20 ha is already part of the existing footprint of TSF1A and East Stockpile. The new proposed footprint of TSF3 is therefore 95 ha. 10.2 Ecological Values 10.2.1 Ruahorehore Stream 10.2.1.1 Catchment Characteristics The Ruahorehore Stream is a large catchment of some 2,000 ha. A sub-catchment of some 20 ha runs southeast to northwest through the proposed TSF3 site to discharge into the Ohinemuri River east of Waihi township (Figure 13). Landuse in the catchment is predominantly pastoral and although the mainstem appears to follow its original course, large areas of the surrounding catchment have been drained with artificial channels. The constructed farm pond, originally a constructed silt pond developed as part of the TSF1A construction programme, now provides a source for stock watering. 10.2.1.2 Habitat Characteristics With the exception of the headwaters, this sub-catchment of the Ruahorehore Stream is characterised by an incised channel of varying width (0.17 - 3.3 m) and depth (0.2 - >1 m), and substrate comprised largely of silt/sand with occasional small gravels and bedrock present. Riparian vegetation is absent along much of its length, although parts in the lower reaches of the Ruahorehore Stream have been subject to planting by OGNZL (see section 4). Bank slumping is evident along much of the stream length, with areas of pugging from stock also present. Macrophytes were often abundant, particularly along the stream edges including the emerged species willow weed and mercer grass (Paspalum distichum) and the submerged species Elodea canadensis and Nitella sp. The headwaters of the sub-catchment (site RUA-forest) is located within a regenerating forest area, upstream of other survey sites (Figure 12). The stream channel is predominantly comprised of large boulders, with a mixture of pools, runs, cascades and waterfalls present. No macrophyte species were present at this site and bank erosion was absent. Vegetation within
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