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Canterbury Strategic Water Study 

Part 3 - Public Consultation 2008

Stage 3 of the Canterbury Strategic Water Study (CSWS) was a preliminary stakeholder assessment of a range of water storage options for Canterbury (options identified previously in Stage 2 of the CSWS).

CSWS Stage 3 is part of a broader consideration of water availability and management. The report and public response to it will contribute to the comprehensive public engagement programme on Canterbury water management planned for 2008/09.

The key findings of CSWS Stage 3 are that - before strategic water storage and water management decisions can be made - rigorous scientific and public consideration is required of:

  • the impacts of land use intensification and its effects on water quality
  • mitigation and management systems for water quality, and
  • methods for maintaining or improving flow variability and low flows in major rivers.

Download and read the document here:

 Final Document  (pdf 717 kB)

Background and introduction

The severe drought of 1998 raised concerns about whether Canterbury would run out of water in the future.

In 2000, the CSWS was initiated to assess the ability of the Canterbury region to meet long term requirements for water. The first stage of the study was a technical evaluation of current and likely future water supply and demand. The 2002 CSWS Stage 1 Report indicated that regionally, on an annual basis, there was adequate water to meet all future requirements but that this did not apply to all catchments individually, and peak demands could not be met on a weekly basis. That is, there is plenty of water in total but it’s not always in the right place at the right time. The study suggested this mis-match of supply and demand could be addressed by the seasonal storage of water, by inter-catchment transfers and through new management methods which manage underground and surface water systems together.

This first stage of CSWS was a joint project between MAF, MfE and Environment Canterbury. Aqualinc were the technical consultants. The CSWS Stage 1 Report is available below.

The Canterbury Mayoral Forum commissioned a second stage of CSWS in 2004, funded by a regional rate, to identify potential water storages in Canterbury, the area they could irrigate and their impacts on river flows. Aqualinc are technical consultants. The CSWS Stage 2 technical report is still in draft form, in part because the third stage of the study (see next paragraph) is identifying additional storage options. The technical report is likely to be released in sections coinciding with the work programme of the third stage of the study. The section on Hurunui storage options is being peer reviewed and should be released by mid 2007.

The third stage of the study, also under the mandate of Canterbury Mayoral Forum, is evaluating the environmental, social, cultural and economic impacts of the water storage options. This evaluation is done by a reference group of people from across Canterbury with a wide range of interests and includes Ngai Tahu and farmers, irrigators, anglers, recreationists, and environmentalists. The Reference Group completed its evaluation of water storage options for Hurunui area at the end of 2006 and is evaluating South Canterbury options in early 2007. It will evaluate options between Waimakariri and Rangitata Rivers in mid-2007.

The results of the Reference Group’s evaluation are being presented to, and discussed with, key interest groups including runanga, district councils, Aoraki Conservation Board, Fish and Game, Forest and Bird and local water development groups. The Group’s evaluation and the key points from discussions with interest groups will be provided to the Canterbury Mayoral Forum and released publicly following the completion of discussions with interest groups. The evaluation of options is expected to be released by mid-2007.

The Reference Group had two days of state-of-the-knowledge presentations from experts on water quality, impacts of land intensification, climate change impacts, social and economic impacts of irrigation, Ngai Tahu and water, electricity and irrigation, in-stream impacts of water abstraction and impact on river-nesting birds. Copies of these PowerPoint presentations are available on request.

A fourth stage of the study is in the early planning stages. It will include integration of potential storages and inter-catchment transfers with surface and groundwater resources. It will also develop and discuss possible institutional and governance arrangements for integrated management and development of water in Canterbury.

Stage 3 additional information

The CSWS is a research and evaluation programme. CSWS does not have a statutory basis and is not part of a RMA process. It will not produce a water allocation plan. The study will, however, bring together in an understandable form a lot of the information that would be used in a regional water allocation plan. The technical parts of CSWS deal only with water quantity. Water quality, in-stream impacts and other aspects are included in the CSWS Stage 3 evaluation of storage options but no technical appraisal of these has been carried out for the study beyond a brief evaluation of in-stream impacts by Dr John Hayes, Cawthron Institute. No site investigations have been made of any of the potential water storage sites. Many of the sites have been identified in previous studies and limited technical information and cost estimates are available from these.

The multistakeholder Group evaluation of CSWS Stage 3 is identifying additional storage options and variations to those identified by Aqualinc, the technical consultants. Aqualinc has modelled these options to assess peak water demand, irrigated area, water reliability, storage drawdown, and changes to river flows.

The Group uses a 22-topic evaluation framework covering a wide range of environmental, economic, social and cultural aspects. The evaluation starts from a technical (primarily hydrological) description of the water storage and river flow changes to identify, in non-technical terms, the key elements and concerns of the proposed options. At the end of each piece of the study (that is, Hurunui area; South Canterbury; Waimakariri – Rangitata area) the group reviews how it feels about each option, the reasons for this and the relative merits of the options for the area.

The Group is not evaluating options that are already in the statutory resource consent process.

The Group believes storage should be considered as part of future water supply in Canterbury. The Group is not an advocate for any particular storage option. The storage options identified in stages 2 and 3 are not development proposals. They merely identify potential storage sites and related infrastructure. The Group’s evaluation identifies a range of environmental, social, economic and cultural concerns which would have to be considered and managed for any of the options to be taken further.

Water resource planning and management is often technical and complex. The Group’s evaluation identifies the key features of each proposed storage option and communicates these and the adverse and beneficial impacts in non-technical manner. Through discussions with key interest groups it seeks to raise awareness of strategic issues to be considered if Canterbury wishes to ensure future generations have adequate water to allow them the choices that reflect their range of values.

The core of the Group evaluating the storage options for all of Canterbury are, with area of interest: David O’Connell and/or Paul Horgan (Ngai Tahu), Graeme Sutton (Irrigation New Zealand), Murray Lane (Water Rights Trust), Claire Mulcock (resource management consultant), Ian McKenzie (farmer, mid Canterbury), Hugh Canard (kayaker), Kelvin Coe (farmer & Selwyn District councillor), Ann Jarman (community development), Ken Hughey (Lincoln University) and Ross Millichamp or Jay Graybill (Fish and Game). Andy Pearce is the independent chair. Six to ten people with local expertise and interests are added to this core group for the evaluations in each of the three areas.

The Group is facilitated by Ian Whitehouse and the meetings with interest groups handled by Grant McFadden.  Technical analysis is provided by Andrew Dark and John Bright, Aqualinc.

Canterbury Strategic Water Study Stage 2

The Stage II report has not yet been completed, although the technical conclusions have been in use for some time and helped define the scope for Stage III. However, you can read the Draft Summary Report – this will form the basis for the Executive Summary when the full report is ready.

 Read the Draft Summary Report (pdf 408 kB)

Read the Stage 1 Report