Significant natural areas of the Waikato region: streams and rivers

Report: TR 2010/19
Authors: Kevin Collier, Bryan Clements, Bruno David, Mike Lake, John Leathwick

Abstract

This report concerns Significant Natural Areas of streams and rivers in the Waikato region, excluding areas incorporated into the region as part of recent local government boundary changes (e.g., around the Hunua Ranges). Significant natural areas of other ecosystem types, including geothermal systems, karst environments and hydro-lakes, are covered in separate reports. The stream and river analyses use a minimum of 2^nd-order catchment planning units as the basis for biodiversity prioritisation, as represented by the River Environment Classification catchment and drainage layers (i.e., springs and other unmapped habitats are not included), for both protected and unprotected land. This report builds on analyses of Leathwick & Julian (2009); specifically, the report: (i) presents a revised Zonation analysis conducted at the 2^nd-order planning unit level; (ii) describes the development and application of the scoring procedure and a ‘biodiversity booster’ data layer; and (iii) presents a draft list of priority candidate sites for further evaluation and assessment. The analyses primarily take account of environmental character, fish community composition, and the distribution of selected threatened species, and do not consider other biological communities such as aquatic invertebrates. A total of 1,494 candidate planning units, equivalent to the highest-scoring 20%, are listed and allocated a priority rating (A-E) following application of biodiversity boosters (potential lowland fish spawning habitat, production forest reservoirs, significant riparian shade, and special sites). Of the highest scoring 20%, 34% occurred in the Coromandel district, 17-18% occurred in the Waitomo and Taupo districts, and 7-8% occurred in the Waikato, Hauraki and Otorohanga districts. Of the “A” rated sites, 70% occurred in the Coromandel and 19% occurred in Waitomo. The high number of priority candidate sites on the Coromandel Peninsula reflects the preponderance of short coastal streams with forested headwaters.

The sites listed require verification and field assessment where appropriate to consider, amongst other things, (i) verification of identified values, (ii) site-specific pressures not accounted for in the Zonation analyses, and (iii) distribution of threatened species not considered as part of this analysis.

Significant natural areas of the Waikato region: streams and rivers [PDF, 926 KB]