The 63-page decision by Justices Lester Chisholm and John Fogarty, released yesterday, allowed Meridian Energy's appeal against the Environment Court decision, which declined consents for the Lammermoor Range wind farm in November, saying the adverse effects on the landscape outweighed the project's benefits.
Meridian was granted consents for the 176-turbine wind farm, which would be the largest in the southern hemisphere, by the Central Otago and Otago Regional Councils in 2007.
Meridian's appeal against the Environment Court decision was heard in the High Court, Dunedin, in June.
Justices Chisholm and Fogarty have told the Environment Court to reconsider its decision, and given direction about what extra evidence should be called.
They found the Environment Court had "erred in law" when it called for alternative locations for a wind farm to be considered as well as an "explicit and comprehensive cost benefit" analysis of those alternative sites.
Central Otago Mayor Malcolm Macpherson said yesterday he was surprised at the strength of the High Court's support of Meridian's appeal.
"At a first reading, I think this opens the door to an alternative outcome.
"The Environment Court may well have to allow the original application and Project Hayes could be back on again."
"That's a remarkable possibility. The Environment Court was at least partly wrong.
"Meridian may yet prevail.
"We may have one of the world's largest wind farms in Central Otago.
"The next few months and years are going to be very interesting," he said.
The groups on both sides of the debate were caught unawares when the High Court decision came out late yesterday, all saying they had no idea the decision was imminent.
Most had not yet viewed the document.
The decision:
• Meridian's appeal allowed.
• Matter referred back to Environment Court.
• Direction given on extra evidence that should be presented.
• Meridian to give evidence on alternative wind-farm sites.
• Environment Court to decide if alternatives would result in fewer adverse effects.
• Further evidence sought on Mahinerangi wind-farm project.
