1 Introduction
1.1 Background
The development of the water resources of the upper Waitaki for hydro-electric power generation during the 1960s and 1970s made possible the complimentary use of the resource for irrigation. In 1966 an interdepartmental committee was set up to report to the Commissioner of Works on the water needs of the farmers in the area in the context of the proposed hydroelectric developments. The commitment to provide water for irrigation was ultimately set out in the 1969 Order in Council that was the instrument that granted water rights to the Minister of Electricity for the Upper Waitaki Power Scheme. The Order in Council allowed for a volumetric entitlement of 172,687,430m3 of water for irrigation for the Mackenzie Basin with at a peak rate of 14.72 cumecs.
In 1990, the Electricity Corporation of New Zealand, that by then owned the Waitaki Power Scheme, opted to not seek a renewal of the Order in Council, but to instead make application to the Canterbury Regional Council for "normal" water rights under the Water and Soil Conservation Act. These were granted in 1991, and shortly afterwards became water permits on the commencement of the Resource Management Act. As a consequence of this sequence, the Order in Council was effectively extinguished in 1991, and this was formally recognised by an amendment to the RMA in 1993.
In 2003, the Environment Court declared that the Order in Council no longer applied. Subsequently, Mackenzie farmers and Meridian Energy entered into separate negotiations and in December 2004 agreement was reached to provide water for up to 60 farms. The provisional deal provides Upper Waitaki farmers with access to a volume of water which is similar to that provided for in the 1969 Order in Council.
McIndoe (2004) estimates that the 172,687,430 m3 of that could potentially be taken annually equated to a continuous flow rate of 5.48 cumecs using the peak flow of 14.7 cumecs for 136 days of irrigation. Using assessed seasonal use based on 900 millimetres for border-strip irrigation and 600 millimetres for spray irrigation being applied to the consented area (3331 ha), only 15 percent of the quantity of water specified in the former Order in Council as being able to be used for irrigation. is currently used. Based on these estimates he considers that a further 25,000 hectares could be irrigated using this water. Irrigation of an additional 25,000 hectares in the upper Waitaki would undoubtedly change the whole character of pastoral farming in the area environmentally, economically and socially.
1.2 Scope of work
The purpose of this document is to report to the Waitaki Catchment Water Allocation Board (WCWAB) on the environmental, economic and social impacts of allocating to irrigation an amount of water that matches the provisions in the now defunct 1969 Order in Council.
The environmental impacts section of this report (section 3) is based on material sourced from existing publications and interviews with a number of people with knowledge of the area and the issues. Economic and social impacts (sections 4 and 5) were assessed using methodologies similar to those used by Harris et al (2004); however, the report does not include an assessment of the economic, social and cultural impacts of any environmental changes.
