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The resource consent hearings lasted an exhausting six months, but the Wairau Valley hydro-electricity scheme is the better for it, and is on the way to becoming a reality and providing much needed security of supply to the region. BY HUGH DE LACY
Critics of the Act, which came into effect in 1991, claimed it would preclude the development of any more of the hydro schemes that today provide 60 percent of the country’s power, even though demand for renewable energy resources is growing inexorably. And while the Wairau, at just 70.5MW, is dwarfed by the giant schemes of last century - the likes of Waikato and Clutha - its imminent construction on a sensitive northern South Island river shows that while the RMA is a significant hurdle, it’s neither an insurmountable nor an unreasonable one. The Wairau River rises in the Saint Arnaud Range of the Nelson Lakes National Park and flows north-east to meet the sea at Cloudy Bay, near Blenheim. It passes through a long valley containing pockets of population, sustained until recently only by merino sheep-farming. Its confluence with the Waihopai River on its eastern flank occurs just a few kilometres south of the burgeoning horticultural township of Renwick, itself just 10 kilomtres south of Blenheim. Lately the Marlborough region’s booming wine and horticultural industries have stretched south up the Wairau Valley, gradually pushing the sheep further into the hills of the Richmond Range to the west and the Inland Kaikouras to the east. Tauranga-based Trustpower already operates three tiny hydro stations in Marlborough, the 7.2MW Branch and 3.8MW Argyle in the Wairau catchment, and a 2.4MW one on the Waihopai, but the region is so starved of its own electricity sources that the new Wairau River scheme takes on a much greater significance than its modest capacity would suggest. At present a typical three-bedroom household in Marlborough is forced to pay up to $350 a year more for electricity than a similar-sized home in Timaru. That’s because 90 percent of Marlborough’s electricity has to be imported through the national grid, either over the western hills from the 32MW Cobb project near Stoke, Nelson, or all the way from Islington in Christchurch. Losses in transmission along the way can amount to as much as 20 percent, making the existing Marlborough supply system highly inefficient. Aside from the three little hydro stations in Marlborough, Nelson’s Cobb is the only generating plant in the upper South Island. All of which made a compelling scenario for a hydro scheme on the Wairau River that, even with the scheme in place, will never flow at less than 10 to 20 cubic metres per second (cumecs), depending on the time of year. But the river also supports populations of rare birds like the black-billed gull and the black-fronted tern, as well as more than a dozen significant wetlands, and native and trout fisheries. Because of this, the hydro scheme was bound to attract broad-based opposition that would challenge the flexibility of the RMA. Trustpower first announced a proposal for a 100MW scheme in 2003. It intended taking water from the upper Wairau after it had passed through the Branch and Argyle stations, running it through a canal on which five more stations would be built, then releasing it back into the river 50 kilometres downstream. From the start, Trustpower was aware of the need to convince both itself and the inevitable opponents of the scheme that it was environmentally sustainable. To this end it turned its original blueprint over to independent consultants for exhaustive analysis, with the legislation ensuring that the consultants’ responsibility was to the process, not the power company. “If the consultants found the scheme didn’t stack up ecologically, we wouldn’t be trying to justify it on purely economic grounds,” Trustpower’s community relations manager, Graeme Purches, told Energy NZ. On the consultants’ recommendation, Trustpower announced in April of 2004 that it was cutting the scheme back to 70.5MW. It followed this up with public consultation, resulting in further changes, notably to the minimum flow regime to ensure lower river flow-rates were unaltered. A projected cost of $240 million was put on the modified scheme. Then came the resource consent hearing. The Marlborough District Council appointed three commissioners, retired judge Tony Willy, environmental planner Max Barber and councillor Jill Bunting, and the hearing commenced on June 12, 2005. Because it involved more than 200 separate consents it ran for a full six months, making it the longest ever under the RMA. Twenty days were given over to the hearing of public submissions alone, of which there were 602 in support and 1033 in opposition. It finally ended on December 12 2005, but it was not until June 22, 2007, that the commissioners issued their 326-page interim approval – a triumph for the open approach Trustpower had taken. The approval was an interim one, says Graeme Purches, because some of the public submitters still wanted the opportunity for input on the conditions, something not possible during the hearing itself. That process is already under way and will move to a second hearing that started on January 21, 2008. Once completed, Trustpower expects the full consent to be issued, with final conditions attached, about the middle of this year. Then it’ll be off to the Environment Court to deal with the inevitable appeals, including from the Department of Conservation and other public and private bodies who have reserved their positions pending settlement of the conditions. But the scheme’s environmental viability has been proven at the consent application level, and it’ll take serious and damaging new evidence for the court to stop it now. Once the scheme gets the final go-ahead, the production work is expected to take two years. The keys to the scheme’s environmental acceptability are the retention of a braided-river system to protect the rare birds from predators, and to secure their food supply; the support that good-quality water will give to the fisheries; a groundwater regime to protect the integrity of the wetlands and create new ones if the originals are damaged; high-maintenance semi-permanent rock structures and temporary gravel bunds to direct the river’s flow into the canal intake; and aesthetically designed power stations similar to the existing ones at the Branch and Argyle. Most importantly from the energy perspective, the Wairau River hydro scheme will transform Marlborough from being 90 percent dependent on imported power to being 80 percent self-sufficient. This, according to Purches, is one of the main reasons Trustpower undertook it. “All our projects are designed to improve the efficiency of supply by generating power closer to where the demand is. We’ve the same principle in mind with the Arnold River scheme on the West Coast, which imports 65 percent of its electricity from Canterbury, and at peak demand loses 19 percent of it in transit,” he says. The Arnold River project is currently undergoing the rigours of the RMA process, but Wairau River is not the first hydro-electric scheme to be put through its hoops. That honour belongs to another Trustpower project, the 5MW Deep Stream modification that was commissioned in Otago in January 2007. It channelled existing flows of water into Lake Mahinerangi to bolster the four power stations of the Waipouri scheme, while at the same time creating a reservoir that provides Dunedin City with an additional water reserve in dry years. Clearly the RMA is capable of reaching a practical balance between environmental and renewable energy considerations. And if Marlborough residents entertained any lingering doubts as to how pressing its renewable energy needs are, they might have been removed in late 2006 when lines company Transpower carried out an upgrade of the Stoke-Blenheim transmission line: Transpower had to install emergency diesel generators in Blenheim, because if a major fault had occurred on the Islington-Blenheim line while the Stoke one was out of commission, the lights would have gone out all over Marlborough.
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It may be the last big hydro-electric scheme to be implemented in New Zealand – and it’s by no means a giant – but if the Wairau River project has proven one thing it’s the Resource Management Act (RMA) is not an insuperable hurdle to major economic development.