Supporting Technical Assessments

Appendix 4: Description of Stream Habitats Boffa Miskell Ltd | Waihi North Project: Freshwater Ecological Assessment | Northern Rock Stack - TB1 Stream TB1 Lower Stream (Figure 4-6) The proposed footprint of the NRS encompasses a significant portion of the stream ‘TB1’ and its tributaries. Site TB1_lower was located on the main TB1 Stream some 200 meters upstream of the confluence with the Ohinemuri River and was chosen for its representativeness of the TB1 Stream. Site TB1_upper was located upstream on a tributary to the TB1 stream and was selected for its representativeness of the stream habitats within the eastern extent of the NRS footprint. Site TB1_lower had a reasonably wide (1.7 – 3.4 m) channel with a predominantly silt/sand substrate with the occasional small gravel present. Water flow was slow, with large and deep pools (up to 1.26 m deep) present along the reach and some areas of anoxic sediment. Riparian vegetation had been planted to approximately 10 m either side and fenced off from the surrounding grazed pasture. Native species such as flax, lemonwood, cabbage tree and mapou 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. TB1 Upper Stream (Figure 4-7) 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 the majority of the reach, with small patches of watercress and starwort (Callitriche stagnalis) also present.

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