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 have been planted, amongst others. The giant umbrella sedge is abundant along the stream edge on both banks, with it extending out to several meters towards the downstream end of the reach. Small areas of active erosion were present along the reach, with bank slumping more apparent at the downstream end of the reach. Macrophytes were rare along the survey reach, with small areas of Nitella sp. present along the survey reach. At the downstream end of the reach the stream channel shallowed and concentrated patches of watercress and water purslane (Ludwigia palustris) were present. Site TB1_upper had a narrow stream channel (0.4 – 0.9 m) with channel incision resulting in comparatively high stream banks (0.5 – 1.0 m). The stream channel was predominantly silt/sand, with some small gravel and patches of bedrock also present. Riparian vegetation was limited, with overhanging pasture grass, Juncus effusus, fern species and Japanese honeysuckle (Lonicera japonica) present. The stream and two metres of the riparian zone are fenced off from stock access. Isolated patches of bank slumping were present along the reach. Macrophytes were common along the reach with mercer grass (Paspalum distichum) present along most of the reach, with small patches of watercress and starwort (Callitriche stagnalis) also present. 11.2.3 Macroinvertebrate Communities Macroinvertebrate communities at the two sites sampled in TB1 had similar macroinvertebrate communities. Lower TB1 was dominated by the amphipod Paracalliope and the upper site by the snail Potamopyrgus antipodarum. EPT taxa present included the double gill mayfly (Zephlebia), the free-living caddis (Polyplectropus), the stick caddis (Triplectides), and the pollution tolerant axehead caddis (Oxyethira). Other taxa present included, amongst others, damselfly, flies, crustaceans and flatworms. The MCI-sb scores for the TB1 ranged from 82.3 to 93.6, both indicative of ‘Fair’ quality (Stark and Maxted 2007). 11.2.4 Fish Populations Fish populations at TB1 were similar at both TB1 sample sites with only the shortfin eel (Anguilla australis) observed during the survey. Site TB1_lower had no apparent fish barriers from the confluence with the Ohinemuri River. Some 150 m downstream of site TB1_upper was a large natural waterfall that would have posed a significant natural fish barrier to swimming fish species. 11.2.5 Stream Ecological Valuation The SEV assessment on site TB1_lower returned a value of 0.501, while site TB1_upper returned a value of 0.409; both of which are indicative of ‘moderate’ quality habitat. The individual attribute scores are listed below in Appendix 5.
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