Native title holders have won a high court appeal, overturning the largest groundwater licence ever granted in the Northern Territory, which would have allowed an agricultural company to extract 40 gigalitres of groundwater – equivalent to draining Sydney Harbour twice – every year for 30 years.The massive water allocation was granted to Fortune Agribusiness for free by the NT government, to support a plan to grow fruit and vegetables in Singleton Station in the central desert.The Mpwerempwer Aboriginal Corporation challenged whether the NT government had lawfully granted the decades-long water licence, arguing the project threatened sacred sites, cultural survival and a fragile desert water system, and claiming it had failed to consider the cultural impact.Sign up for the Breaking News Australia email That argument failed in the NT supreme court and the territory’s court of appeal.The NT government said the courts had already correctly identified the law did not impose an obligation on a government minister to consider the impact on Aboriginal cultural values.But the high court on Wednesday ordered the water licence to be quashed, referring the water licence application back to NT decision makers, who will have to consider environmental approvals.The court ruled the relevant NT minister did not address special circumstances to justify the water licence for an extended period of 30 years.It ruled the minister also did not form a “state of satisfaction” that such special circumstances existed.The decision “contravened express and implied limitations on the decision-making authority conferred on the delegate minister,” the court ruled.The making of the decision should have included the Aboriginal corporation being given notice of proposed conditions and an opportunity to be heard in a written submission, they said.However it ruled it was given “no such notice and no such opportunity”.The Mpwerempwer Aboriginal Corporation argued the water licence risked permanently damaging an ancient aquifer, at least 40 groundwater-dependent sacred sites and community water supplies.In a statement released by the Central Land Council on behalf of the Mpwerempwer Aboriginal Corporation, native title holder Valerie Curtis said it had “been a really long journey for us mob”.“We wasn’t going to give up. We was gonna continue to fight, but I’m glad that we did get a really good outcome from the High Court, and we’re really happy,” she said. “Those elders that have passed on, they would be really happy and proud of what we have achieved for our country.”