Supporting Technical Assessments

14 Water quality data collected by OGNZL from the Mataura Stream between 2015 and 2018 was assessed and additional samples for water quality analysis were collected from two sites (Mataura Stream and unnamed tributary 2) within the Mataura Stream catchment. The results are compared with the site-specific criteria established for the Ohinemuri River as described above and WRC water quality guidelines2 for water quality. Where appropriate, water quality is also assessed against the relevant NOF attribute values. 6.4 Assessment of Ecological Values and Effects of WNP Ecological value has aspects of both quantity (rarity or extent) and quality (integrity, functionality or condition) and incorporates an array of attributes across multiple levels of ecological organisation (species, communities, habitats and ecosystems). Environment Institute of Australia and New Zealand (EIANZ) impact assessment guidelines (EIANZ 2018) provide a summary scale whereby a site’s value is assessed as the extent to which an area or site exemplifies qualities of representativeness, rarity/ distinctiveness, diversity and pattern, and ecological context characteristic of its ecosystem type and then ranked on a scale of Negligible to Very High for how many of those assessment matters are met (Table 1). We have assessed terrestrial and wetland ecosystems / communities / habitats and species against these criteria to determine the overall value of the features. Table 1: EIANZ criteria for ascribing ecological value (EIANZ 2018). Value Description Very high Area rates High for 3 or all of the four assessment matters (representativeness, rarity/ distinctiveness, diversity/pattern, ecological context) High Area rates High for 2 of the assessment matters, Moderate and Low for the remainder, or Area rates High for 1 of the assessment matters, Moderate for the remainder Moderate Area rates High for one matter, Moderate and Low for the remainder, or Area rates Moderate for 2 or more assessment matters Low or Very Low for the remainder Low Area rates Low or Very Low for majority of assessment matters and Moderate for one. Limited ecological value other than as local habitat for tolerant native species. Negligible Area rates Very Low for 3 matters and Moderate, Low or Very Low for remainder. Freshwater values were assigned based on the attributes outlined in the EIANZ guidelines. Ecological values are ranked on a scale of Negligible, Low, Moderate, High, or Very High based on these characteristics (Table 2). 2 Guideline values sourced from https://www.waikatoregion.govt.nz/Environment/Natural-resources/Water/Rivers/healthyrivers/How-wemeasure-quality/#:~:text=Water%20quality%20is%20measured%20by,may%20be%20unacceptable%20for%20others. on 24/07/2020.

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