1. Introduction
The Waitaki River is one of New Zealand's largest braided rivers and has a wide range of ecological, economic, social, and cultural values (Fig. 1 shows the Catchment boundary). The Resource Management (Waitaki Catchment) Amendment Act provides for the establishment of a Board to develop a water allocation plan for the Waitaki River Catchment. The Board has 12 months from September 2004 to develop and implement a water allocation plan for the Waitaki River Catchment. Environment Canterbury will administer the plan when it is operative.
The Ministry for the Environment is drawing together a range of information on the Waitaki Catchment for the Board to use when developing the water allocation plan. Catchment information being collated at the time of writing this report included reports on hydrology, recreational values, water demand, and freshwater ecological values. Kingett Mitchell was engaged by Ministry for the Environment to collate the freshwater ecological data and present it in a Geographical Information System (GIS) format. The objectives of this investigation were to:
- develop an understanding of the range of freshwater flora and fauna associated with the rivers and beds, banks, margins, tributaries, lakes, islands, wetlands and aquifers of the Waitaki Catchment
- develop a graphic presentation that identifies their location including the location/s where different lifecycle stages of fauna species that may be related to or influenced by flow occur eg, fish spawning and bird nesting
- highlight areas of the Catchment where there is insufficient information to make an assessment of freshwater ecological values.
It is important to note that this project was an information collection and presentation exercise. Therefore, no assumptions regarding the relative importance of the various freshwater ecological values shown in the GIS have been made beyond the Department of Conservation's (DoC) threatened species classification system (Molloy et al., 2002).
This report is a companion to the freshwater ecology data collected, collated and presented in a GIS format by Kingett Mitchell for Ministry for the Environment. The purpose of this report is to:
- briefly summarise coverage of the Catchment with ecological values data and compare to known water allocation pressure areas
- provide support to the freshwater ecology data in the GIS provided to Ministry for the Environment (herein referred to as "GIS data")
- describe for each group of GIS data its age, source, strengths/weaknesses, geographic spread within the Catchment, and any caveats on the use or coverage of the data
- identify where there are gaps in ecological information - both in terms of spatial coverage, and in terms taxonomic groups
- develop a GIS-based tool for (fish) ecological values mapping, using the River Environment Classification (see explanation in Section 4 below).
This report starts with a summary of freshwater ecological values in the Waitaki River Catchment, then discusses the data sources in detail. Section 2 provides an overview of the GIS outputs and describes biological groups, life stages represented, the spatial distribution of ecological values, and assesses ecological values within the Catchment. Section 3 describes the various sources of the GIS data used, and discusses additional sources of ecological information not used for this project. Section 4 describes the attributes of each of the GIS layers, and includes methods on how the River Environment Classification was used to model freshwater fish distributions within the Catchment. Sections 5, 6 and 7 include acknowledgements, literature referred to in the body of the report, and a bibliography of additional related literature not referred to in the report.
