EGL Ref: 9215 23 June 2022 Page 5 This report shall only be read in its entirety. File: WAI-985-000-REP-LC-0002_Rev0.docx. 3.0 SITE CONDITIONS 3.1. Climate The climate within Waihi is temperate. Mean monthly temperatures range from 8.9 °C in July to 18.9 °C in January. Waihi township is approximately 100 m above sea level and receives on average between 1500 to 3000 mm of rainfall per annum, with approximately 31% of rainfall expected within the winter months between June and August and 22% of rain in the summer months between December and February. 3.1.1. Climate change NIWA has published information on possible effects of climate change. The effects will generally result in higher temperatures, lower annual rainfall but higher intensity rainfall in extreme events. Higher temperatures and lower annual rainfalls are considered unlikely to affect tailings or rock disposal. Higher intensity rainfall events can be considered in the design of drains, surface water collection ponds, and freeboard within the TSF impoundments. NIWA provides high intensity rainfall data for different climate change scenarios. 3.2. Geological setting 3.2.1. Tectonic setting Earthquake hazard at the Waihi operation was assessed by the Institute of Geological and Nuclear Sciences (GNS) in 2017 (Ref. 2). GNS is a New Zealand Crown Institute and is one of New Zealand’s leading authorities on seismicity in this country. The Waihi operation is in the northwestern region of the New Zealand tectonic setting, which is experiencing tectonic crustal extension as shown on Figure 4, as opposed to dextral (lateral) or contractional tectonic mechanisms present in other parts of New Zealand. This extensional region typically experiences lower seismicity compared to more central parts of New Zealand because of its distance from the interface between the Australian and Pacific Plates shown in Figure 4. The Waihi operation location is marked MH for Martha Hill. To the southeast and east of Waihi is the more active Extensional Havre Trough, Taupo Rift, North Island Fault Belt and the Northwest dipping Hikurangi Subduction Zone regions.
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