28 main stem also had a comparatively lower score for riparian vegetation intact due to a small section that was naturally more incised. 7.4.6 Waiharakeke Stream: Summary of Ecological Values The Waiharakeke Stream catchment has good instream habitat quality and quantity consisting of an array of different habitats, including, riffles, runs, pools, undercut banks and coarse woody debris. Fine sediment cover was minimal and only found in sheltered areas behind large woody debris or boulders. Macroinvertebrate assemblages and indices were reflective of the excellentquality habitat with many sensitive taxa. Fish species records within the catchment also showed high diversity with seven native fish species recorded. Riparian vegetation and stream shading were high with vegetation consisting of late succession and mature forest species. The streams were in a natural state with no modification. Based on the EIANZ criteria we have assessed the Waiharakeke Stream reaches as comprising Very High ecological value. 7.5 Wetland Delineation and Ecological Values 7.5.1 Mataura Wetland The Mataura wetland is a well-defined transitional “damp area” where there is an obvious visual ecotone and a functional wetland, where the soil profiles reveal a persistently high water table, along with the presence of wet tolerant grasses and rushes (Appendix 3). GHD (2022b) has developed a conceptual hydrology for the wetland that concludes that the inferred water source for the defined wetland is a combination of surface water via runoff and direct rainfall, interflow from infiltrating rainfall within the catchment and groundwater baseflow. Evidence of historic wetlands within this area were observed with the presence of two mature swamp maire (Syzygium maire), a once common wetland tree, now with a threatened status raised to Nationally Critical in 2017, following the arrival of myrtle rust in NZ7. In addition, many populations now persist as remnants within partially drained farmland, such as at Willows Road Farm. 7.5.2 Tributary 1 Gully Gully feature 1 is a constructed farm pond created by an embankment/causeway on tributary 1. The embankment has a small-sized outlet pipe located high on the embankment to provide for the detention of ponded water. The downstream outlet of the pipe is perched thus preventing the passage of fish upstream. The sizing and location of the outlet pipe shows it has been clearly developed as a farm pond for the purpose of retaining water. The feature thus meets the exclusion as a wetland constructed by artificial means. Historical photographs show that clearance for farmland had begun in the area by 1942 and was completely cleared by 1999 (Appendix 2). 7 Threatened status footnote
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