Jemena Gas Networks (NSW) Ltd v Mine Subsidence Board

The High Court of Australia heard an appeal from Jemena Gas Networks (NSW) Ltd (the appellant) against the Mine Subsidence Board (the Board). The dispute concerned the appellant's entitlement to compensation from the Mine Subsidence Compensation Fund for expenses incurred in performing preventative and mitigatory works on a gas pipeline. These works were undertaken after the appellant received expert advice predicting that longwall mining would cause subsidence and damage to the pipeline.

The central legal issue before the High Court was the proper construction of section 12A(1)(b) of the *Mine Subsidence Compensation Act 1961* (NSW). Specifically, the Court had to determine whether the phrase "from a subsidence that has taken place" required that the subsidence must have actually occurred *before* the owner incurred expenses to prevent or mitigate damage, or if it encompassed a hypothetical or anticipated future subsidence. The Court also considered whether the appellant's claim for expenses incurred in preventing or mitigating damage was valid under the provision.

The High Court reasoned that the language of section 12A(1)(b) did not mandate that subsidence must have already occurred for an owner to be entitled to compensation for preventative or mitigatory expenses. The Court held that the provision allowed for claims where an owner could reasonably anticipate that damage "would otherwise have arisen, or could reasonably anticipate would otherwise arise, from a subsidence that has taken place." This wording indicated that the provision was intended to cover both actual past subsidence and reasonably anticipated future subsidence. Therefore, the appellant was entitled to compensation for the proper and necessary expenses incurred in preventing or mitigating damage to its pipeline, even though the full extent of the subsidence had not yet manifested at the time the works were undertaken, provided the damage was reasonably anticipated.

The High Court allowed the appeal, setting aside the orders of the Court of Appeal and the Land and Environment Court. The Court ordered that the preliminary question of law be answered in favour of the appellant, confirming its entitlement to compensation from the Mine Subsidence Compensation Fund for the proper and necessary expenses of preventing or mitigating damage to its pipeline, based on reasonable anticipation of subsidence from approved longwall mining. The Board was ordered to pay the appellant's costs.