5 The Environmental Setting

TPL purchased the Branch Scheme from Marlborough Electric in 1998 after government legislation forced the separation of power generation assets from power distribution assets. Marlborough Electric then ran the scheme under contract for several years. This was a time when TPL purchased a number of smaller hydro-electric power (HEP) schemes around the country (another nearby example being the Arnold Power Scheme on the West Coast), and they found the Branch Scheme to be amongst the most reliable.

Prior to TPL purchasing the Branch Scheme, Marlborough Electric had initiated a study that looked at taking and diverting water from the Wairau River to the Argyle headpond. This would have added about 30 gigawatt hours (GwH) to the 55 GwH generated by the Branch Scheme. TPL reviewed this proposal and decided it was not economic at that time. It did however “spark the idea” of taking water from the Wairau River straight into the second (lower) power station of the Branch Scheme. TPL undertook a scoping study of that proposal which was completed in 2002. At the same time they reviewed some of the (former) Ministry of Works and Development ideas about possible further power development in the Wairau Valley. At this time an irrigation company was formed in the Wairau Valley, given which TPL “did some numbers” and launched the proposed scheme publicly at the end of 2002.

Several years of intensive investigations followed prior to the first tranche of consent applications being lodged with the MDC in July 2005. As the MDC is a unitary authority with both regional and territorial authority functions, it was the sole consent authority for all the applications. Evaluation of the work undertaken by TPL as part of the Assessment of Environmental Effects (AEE) that accompanied the resource consent applications was beyond the scope of this project to review. However, most of this work was undertaken by external contractors, many of whom are nationally recognised in their fields of expertise.

In simple terms TPL propose to divert up to 40 cubic metres per second of water from the Wairau River to a canal about 2km upstream of the Branch River. The water will then be passed through the (upgraded) lower power station on the Branch River, and then along a canal totaling about 45.5km in length. Five other power stations are proposed to be constructed on the canal, with the canal itself crossing several ephemeral and permanent watercourses and criss-crossing a major faultline. Head is generated for each power station by the canal following the contours of the valley, with the proposed route very largely to the south of the State Highway along the south bank of the Wairau. Water is returned to the Wairau River some 49km downstream of the point of take.

For most of its length the canal is on private land. TPL has purchased properties, or successfully negotiated access agreements with all but two landowners. One of these owns a property on which the lowest headpond, power station and discharge tailrace is proposed to be built. Later this year the Environment Court is scheduled to consider whether appeals on the merits of the proposal will be heard given the landowners refusal to enter into a either a purchase or access agreement with TPL.

Several interview respondents were involved in early consultation undertaken by TPL prior to resource consent applications being lodged. While they said this demonstrated good faith, they observed that TPL took the line that this was a fairly firm proposal and were not prepared to negotiate the substantial mitigation that was sought by some of those interviewed. Further additional consultation carried out prior to applications being lodged was described as being little more than a description of the proposal.