33 Fifth, the significance of the Board carrying out works pursuant to s 13A to "reduce the total prospective liability of the Fund" and its relationship to or influence upon the proposed construction of s 12A(1)(b), is to be found in the following passage from the Minister's Second Reading speech with respect to the 1969 amendment to the Act which inserted ss 12A and 13A and which preceded the passages recorded in [20] above:
"The bill will provide also for the carrying out of works by the board to prevent or mitigate subsidence damage before it [the damage] occurs. Proposed new section 13A will empower the board to carry out such works where the total prospective liability of the fund will thereby be reduced."
34 When that passage from the Minister's speech is read with those set out in [20] above, it becomes apparent that first, the objective of reducing the prospective liability of the Fund by the carrying out of preventative works is left to the Board. Second, it is only in the context of that power of the Board that the concept of the costs of prevention being often cheaper than of cure was regarded as relevant. Third, it was only in the context of emergencies (where presumably the Board's power under s 13A could not be exercised in a timely fashion) that it was contemplated that the owner of improvements would carry out preventative or mitigating works arising from a subsidence that had taken place.
35 In other words the Minister was speaking of an emergency arising when subsidence has occurred but damage, although anticipated, has not yet arisen but will do so unless works to prevent or mitigate it are carried out. Although it is true that costs of prevention are often cheaper than the cure, the scheme of the legislation in my view is as follows:
(a) payment from the Fund of compensation for damage to improvements that arises from subsidence that has taken place (s 12(1)(a));
(b) compensation for damage incurred as a result of the exercise by the Board pursuant to s 13A of its power to carry out works to reduce the prospective liability of the Fund by preventing or mitigating damage that the Board anticipates would, but for those works, be incurred by reason of subsidence including anticipated subsidence; and
(c) payment of compensation from the Fund in an amount to meet the proper and necessary expense incurred or proposed to be incurred in preventing or mitigating damage to improvements which their owner could reasonably have anticipated would otherwise have arisen or could reasonably anticipate would otherwise arise from a subsidence that has in fact taken place but is yet to cause damage or significant or more extensive damage (s 12A(1)(b)).
36 Thus his Honour, with respect, was in error when he held that the subsection was both ambiguous and obscure because it referred to expense incurred in preventing or mitigating damage which could be reasonably anticipated from subsidence that "has taken place" by which time the damage would have occurred. As I have observed in [30] above, the flaw in this reasoning is that it assumes that subsidence and damage inevitably occur simultaneously.
37 Common sense would indicate that some subsidence may take place but may not be so extensive as to cause immediate or significant damage to surface improvements located over or near to the area which has subsided. Further subsidence may be anticipated which, without the taking of preventative or mitigating measures, is likely to cause damage or greater damage to those improvements. It is only in that sense that s 12A(1)(b) contemplates damage arising from anticipated subsidence. But some initial subsidence must have taken place before the subsection is engaged.
38 The terms of s 12A(1)(b) are therefore directed to the situation where subsidence has taken place but damage has not yet arisen therefrom but could reasonably be anticipated to do so if works to prevent or mitigate such anticipated damage are not performed.
39 Sixth, further support for this construction of s 12A(1)(b) is to be found in s 12A(2)(b) which requires that a claim for payment of an amount under subsection (1)(b) is to be made within three months after the day on which the expense to which the claim relates becomes known to the claimant or, where some other time is prescribed by the Regulations, within the time so prescribed. With respect, the primary judge's construction ignores the impact of this provision. His Honour held (at [18] and [19]) that one of the elements that must exist in order for a claim for compensation to be made under subsection (1)(b) is that there must have been subsidence at or before the time of making the claim. Accordingly, on that construction and given the provisions of s 12A(2)(b), the claim could only be made if the subsidence had taken place within three months after the day on which the expense to which the claim relates has become known to the claimant. It would be anomalous, if not irrational, for subsection (1)(b) to be construed to only require the subsidence to have taken place by the time of the making of a claim which is barred if not made within the three months referred to in subsection (2)(b). In other words, unless the anticipated subsidence takes place within that period, no claim can be made.
40 In supplementary written submissions on this point the appellant countered that the subsidence need not take place, as the primary judge had held, before the claim for payment was made provided it took place before payment was made from the Fund. In other words, the occurrence of subsidence was a condition precedent only to an amount under s 12A(1)(b) becoming payable. The payment of a claim made within the nominated three months would, therefore, be postponed unless and until "a subsidence … has taken place". Such a construction, so it was submitted, would be consistent with the necessity for the Board to be notified timeously of the claim so that, like an insurer, it could make provision for it even though it may or may not crystallise into a payment from the Fund. Further, it would not give rise to the anomaly referred to in the preceding paragraph.
41 Although the appellant sought to call in aid the terms of a regulation made for the purpose of s 12A(2)(a), accepting that no such regulation had been made for the purpose of s 12A(2)(b), in my opinion it is well established that as a general rule it is impermissible to call in aid in the construction of an Act delegated legislation made under that Act: Pearce & Geddes "Statutory Interpretation in Australia", 6th ed. (2006), Chatswood, [3.41] pp.104-105 and the cases there cited. It was not suggested by the appellant that the regulation in question and the Act formed part of a legislative scheme which, for the purpose of ascertaining but not construing that scheme, permits of a partial exception to the general rule.
42 In my opinion, the construction contended for by the appellant whereby the taking place of a subsidence is only a condition precedent to an entitlement to payment of the relevant expense from the Fund, cannot stand with the clear words of s 12A(1)(b). The requirement for damage that the owner could reasonably anticipate would have arisen or would arise "from a subsidence that has taken place" is temporally linked to the making of a claim, not to the payment of a claim already made. Although, as the appellant submitted, there must be a causal link between the anticipated damage and a subsidence that has taken place, there is also a temporal link required between the making of the claim and that to which the claim relates, namely, the incurring or proposal to incur an amount to meet the proper and necessary expense in preventing or mitigating damage to improvements that, in the opinion of the Board, the owner could reasonably have anticipated would otherwise have arisen, or would reasonably anticipate would otherwise arise, from a subsidence "that has taken place" - not one that "will take place" or that "takes place".
43 The better view, therefore, is that the Board should be in the position to assess and pay the claim upon it being made: not that it be merely notified of a claim the assessment of which must be postponed unless and until a subsidence "takes place" some time in the indeterminate future.