Supporting Technical Assessments

Appendix 4: Description of Stream Habitats Boffa Miskell Ltd | Waihi North Project: Freshwater Ecological Assessment | Site RUA_lower is a reasonably wide (2.2-3.0 m) and deep (x̅ 0.67 m) stream with a silt/sand channel. Water flow was moderately swift, with the survey section one large, deep, run section. Macrophytes were abundant within the reach, with large areas of watercress (Nasturtium officinale), water pepper (Persicaria hydropiper) and Canadian pondweed (Elodea canadensis) present along the reach. Smaller patches of the submergent species Nitella sp. and blunt pondweed (Potamogeton ochreatus) were also present. There was no riparian vegetation present, with the stream surrounded by grazed pasture. Bank slumping was evident along the reach, with areas of pugging from stock also present, particularly on the true left bank. Site RUA_upper is located within grazed pasture, fenced off from stock with an electric wire along the top of the stream bank. The channel is reasonably narrow (0.17-1.48 m) with high (>1 m), almost vertical stream banks. The channel is predominantly smooth clay and silt/sand, with some smaller gravels present. Water within the reach is exceptionally clear, with a mean depth of 0.28m. Macrophyte species were rare with small patches of watercress and starwort (Callitriche sp.) present. However, large areas of bank collapse have resulted in large patches of pasture grass species within the stream channel. Riparian vegetation consists of overgrown pasture grass species with the occasional fern and gorse (Ulex europaeus) and other groundcover weed species present. Site RUA_forest is located within a regenerating forest area, upstream of the two other survey sites. The stream channel is predominantly comprised of large boulders, with a mixture of pools, runs, cascades and waterfalls present. Stream width was variable (0.6-2.32 m) and had an average depth of 0.20 m. No macrophyte species were present along the survey reach and no areas of bank erosion wo0ere observed. Vegetation within the riparian zone is dense with black tree fern (Cyathea medullaris) the dominant species, with some remnant mature pine trees present. The understory is predominantly native with species such as gully fern Pneumatopteris pennigera), mahoe (Melicytus ramiflorus), hangehange (Geniostoma ligustrifolium), soft mingimingi (Leucopogon fasciculatus) and silver fern (Cyathea dealbata) present. African club moss (Selaginella kraussiana) is the dominant ground cover, this is an invasive weed species that can prevent the establishment of native seedlings. Bryophyte species abundant along the stream banks. Site RUA_Trig_Road is located on the Ruahorehore Stream, adjacent to the proposed TSF3 stockpile areas, but outside the footprint of works. The reach is located within grazed farmland and is fenced off from livestock. The stream has a variable width (1.8 – 3.4 m) and is moderately deep (x̅ 0.56 m). The streambed was almost entirely comprised of silt/sand with rare small gravels present. Periphyton was abundant. Macrophytes were 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. Stream shading was low, with riparian vegetation limited to a few specimen exotic trees and pasture grass.

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