Appendix 3: Methods for Assessment of Stream Freshwater Ecology Boffa Miskell Ltd | Waihi North Project: Freshwater Ecological Assessment | Freshwater surveys were undertaken during autumn and spring 2017 and autumn 2019, at selected sites within the vicinity of the proposed footprint of works at the Northern Rock Stack (NRS), Gladstone Portal laydown and TSF3 areas. A preliminary site visit was undertaken within each works area, with watercourses within the area walked, in order to select suitable stream reaches to survey at a later date. Stream reaches were selected based on their suitability to undertake the survey methodology and their representativeness of the wider freshwater environment(s) within the works footprint. Stream survey assessments followed the Auckland Council Stream Ecological Valuation (SEV) Assessment Methodology as outlined in Auckland Council (2011). Although the SEV methodology is not mandatory, and was developed for the Auckland region, it is increasingly accepted as best practice for informing stream loss and stream mitigation assessments, and our experience is that it is accepted for use in the Waikato region. As part of this assessment fish and invertebrate communities are assessed. Fish communities were surveyed through electric fishing and the use of a NIWA backpack mounted EFM300 electric fishing machine and following standard protocols as outlined in the DOC electrofishing guidelines (DOC 2013). Macroinvertebrates were collected and processed in accordance with national standard protocols C2 and P3 as described in Stark et al (2001). A total of seven SEV surveys were undertaken; two within the NRS footprint; two within the TSF3 footprint; two within the TSF3 downstream receiving environment of the Ruahorehore Stream and one on the upper reaches of the Ruahorehore Stream outside the footprint of works. The surveys were carried out during autumn 2017 and autumn 2019. The SEV sample sites were selected so as to be representative of the types of stream reaches impacted and to be restored. No assessments of water quality were carried out as part of these surveys. As outlined in section 4.2.3 above, the water quality of the Ohinemuri River and the Ruahorehore Stream is collected as part of the monitoring programme undertaken and reported on by OGNZL Stream Classification Streams were inspected and classified using the definitions in the Glossary Section of the Waikato Regional Plan (2012; Online Version), as follows: River: A continually or intermittently flowing body of fresh water and includes a stream and modified watercourse; but does not include any artificial watercourse (including an irrigation canal, water supply race, canal for the supply of water for electricity power generation, and farm drainage canal). Perennial stream: A stream that flows all year round assuming average annual rainfall. Ephemeral stream: A stream that flows continuously for at least three months between March and September but does not flow all year. Modified watercourse: An artificial or modified channel that may or may not be on the original watercourse alignment and which has a natural channel at its headwaters. Artificial watercourse: A watercourse that contains no natural portions from its confluence with a river or stream to its headwaters and includes irrigation canals, water supply races, canals for the supply of water for electricity power generation and farm drainage canals. Farm drainage canal: An artificial watercourse on a farm that contains no natural portions from its confluence with a river or stream to its headwaters and includes a farm drain or a farm canal.
RkJQdWJsaXNoZXIy MjE2NDg3