Plaintiffs v Defendants

communications between the defendants and Marshall Day Acoustics comprising instructions issued by the defendants to Marshall Day in respect of the Pre-Development Noise Report, the Round 1 and Round 2 Noise Compliance reports, and the Sound Power Report, and the background re four particular reports that were referred to in the pleadings and background noise monitoring undertaken on the Baxter Land between 25 July and 17 September 2019 (as well as any report in relation to that monitoring).[2]

1. The terms of the discovery reflected the defendants' proposed order with respect to this category.
2. The second category (Category 21) sought documents 'concerning any defects with any of the turbines affecting the noise generated by those turbines'.[3] This category was refused.
3. The relevant principles were not in dispute:

(a) to be discoverable the documents have to be directly relevant to the issues in dispute in the proceeding;

(b) defining the issues in dispute is by reference to the pleadings before the Court; and

(c) the discovery exercise must be proportionate and relevant to the issues, and court supervision of the discovery process and orders are made in the context of its overall obligation to facilitate the just, timely and cost effective resolution of the real issues in dispute.[4]

1. The plaintiffs' pleading alleges that the sound, comprising sound, infrasound or vibration (together Sound) contains 'Special Audible Characteristics' emanating from the turbine that have caused a substantial interference to the plaintiffs' use and enjoyment of their land that is unreasonable.[5] The claim for exemplary and aggravated damages pleads a failure to take care and a refusal to mitigate, based upon knowledge of the defendants.[6] The knowledge is particularised to include MDA acoustic reports dated 8 April 2019, 9 February 2022 and the background monitoring in 2019 referred to in the Judicial Registrar's order.
2. The defences admit the emission of Sound at levels documented in the reports of MDA dated 3 August 2022 and 4 August 2023. They deny that the Sound, containing special audible characteristics, is unreasonable, and particularise the denial by reference to the two aforementioned reports and the Pre-Development Noise report of 9 April 2019.[7]
3. The defendants resist both categories of discovery on the bases of relevance and proportionality.

1. The plaintiffs submit that each category, namely categories 10 and 21, is relevant. As to Category 10, they submit that all reports (including drafts of those reports), and all communication between the defendants and MDA concerning the wind farm, are relevant. That relevance arises in two ways: first, in relation to the levels of noise interference sustained by the plaintiffs as well as, second, to the defence pleading that, in reliance on or acting in accordance with particular MDA reports, the defendants were acting reasonably. They submit that any communication and drafting prior to the provision of a final report is relevant to test the independence of those final reports, and the ingredients or basis upon which they were provided. They submit the commercial interaction between client and contractor in producing a final report is a relevant matter.
2. In relation to Category 10, the plaintiffs submits that the pleadings, in particular paragraph 13(D) as to reasonableness, raise the defendants' reliance on testing compliance with the permits. The defendants resist this and maintain the position that the orders made by Judicial Registrar Lorenz, referring to communications comprising instructions and confining those communications to five specific subject matters as identified in the pleadings, is the appropriate limit for relevance in this category. They contend that nine years of correspondence, confined only by communications relating to the wind farm, is too broad so far as relevance is concerned and is oppressive in terms of the volume of material. It also submits that by Category 9, which is or has been ordered, all of the field testing and testing of special audible characteristics as identified will be provided. Further, the defendants submit that a number of other reports authored by MDA are publicly available, and that it is clear from the affidavit of Dominica Tannock, that the plaintiffs already hold those reports. The evidence does not indicate how those reports might assist or contextualise the reports that are referred to in the pleadings. The defendant says that the methodology used by MDA is not in dispute on these pleadings. Category 9 will discover the raw data and specifications on which the reports are based, and instructions provided by the defendants for the commissioning of those reports and any subsequent instructions as to their conduct is caught by the Category as identified by the Judicial Registrar's orders.
3. The plaintiffs seek Category 21 on the basis that the existence of defects in the turbines goes to its engagement with the manufacturer, Vestas, as to the 'special audible characteristics' of the sound as defined by the pleadings. Further they submit that 'defects' are or may be relevant to explain the noise levels.
4. The defendant submits in relation to Category 21 that the issue of defects is not raised by the pleadings and therefore the existence of defects is not a matter in issue in the proceeding. Paragraph 13(E) of the amended statement of claim which pleads engagement with Vestas does not allege that this engagement was in relation to defects, and the same point is raised in relation to paragraph 21(b). The pleadings address the defendants' steps or knowledge as to the extent or nature of issues relating to sound and in particular the special audible characteristics.
5. The defendants also contend that categories 7, 8, 14 and 20 cover the field in relation to the causation of characteristics of noise that have the 'special audible characteristics'. The other categories will identify the extent to which those matters are caused by some defect or not. Beyond that, the pleadings do not deal with defects and so the category has no relevance. Secondly, the defendants submit that the category is fishing. To do so, they rely on the plaintiffs' own material, which is premised upon the submission that 'if' there are defects, then those are matters that should be brought to light through discovery.

1. Firstly, the question of relevance is determined by the issues exposed by the pleadings, and not necessarily by the form of the pleadings themselves. While particulars inform and help define those issues, the reference to a particular document upon which a party expressly relies does not in itself limit discovery to that document. The issue of relevance is also informed by the content of r 29.01 of the Rules, which provides that discovery is to include documents on which the party relies that adversely affect the party's own case, which adversely affect another party's case, and that support another party's case. Clearly, those four categories contemplate documents that are relevant and meet those criteria. If there are other reports commissioned by MDA going to the levels of Sound emissions from the turbines during operation, other than those specifically referred to in the amended statement of claim or defences, then those reports are relevant to the issue of whether the Sound is capable of causing a substantial interference or is unreasonable as the pleadings expose that issue. In my view, the limitation of reports to those specifically mentioned in particulars or in the pleadings is unnecessarily narrow.
2. Second, in the context of a commercial engagement of experts for the purpose of predicting or measuring noise for the design and operation of the windfarm, in my view the commercial interaction that generates those reports is relevant. If there are draft reports provided to the client defendants, then those documents and the exchange of communication surrounding the provision and comment on those drafts is relevant. The correspondence of the defendants first raised the limitation of discovery to 'final reports',[8] it seems probable that there are drafts that have been provided. While some of that correspondence surrounding the generation of the reports would be caught by the order requiring discovery of instructions, in my view that limitation of discovery in this way is too narrow. Discovery ought encompass both requests from the consultant for further information, comment or instruction as well as the defendants' responses.
3. However, I accept that the category identifying all correspondence concerning the wind farm is too broad. I propose limiting the category to documents concerning the identified reports and the process of their commissioning and finalisation. I also propose to limit the category by a time period to reports that are dated on or after April 2019, the date from which knowledge is pleaded in the plea for exemplary and aggravated damages and any reports from an earlier date that were provided for the extension of the permit on 4 February 2018, as referred to in paragraph 3 of the defences. I will allow discovery of Category 10 in this broader form.
4. In relation to category 21, I do not accept that an issue as to defects in the turbines is raised by the pleadings. It is not put that the tonal audibility issues, or the special audible characteristics that are admitted to describe some elements of the noise nuisance, are necessarily the result of any defect. The pleading do not engage with the claim that noise levels are affected by defective turbines. Insofar as the causation of noise as distinct from its level and nature is at issue, categories 7, 8, 14 and 21 deal with documents that would disclose documents relating to the cause of the tonal audibility issues and any responses thereto.
5. The plaintiffs have not persuaded me that it is relevant to know whether the matters upon which the defendants rely in pleading the reasonableness of their response are responses to a defect or otherwise. Category 21 is in my view not a category of relevant documents.
6. The plaintiffs had an alternative plea in relation to Category 21. They pleaded that that ground was found to be relevant, but oppressive in its breadth. They suggested that s 55 of the Civil Procedure Act 2010 (Vic) could be utilised to craft an order that the defendant provide an affidavit of steps taken to ascertain defects to ameliorate the proportionality issue. Given my findings of relevance, it is not necessary to take that matter any further. It was characterised by Mr Quinn as an offer to the defendant of an alternative way of proceeding to an order for discovery in the traditional sense, a matter which Dr Hanak declined to take up. Nothing more needs to be said about that aspect. The circumstances therefore I will allow the appeal and make the following orders:

(a) The defendants are to make discovery of documents in Category 10 described as communication between the defendants and Marshall Day Acoustics relevant to the commission of reports pertaining to sound generated by the turbines including draft reports provided to the defendants. The reports are not limited to the pre-development noise report, ground 1 and ground 2 noise compliance reports, sound power report, and the background noise monitoring undertaken on the Baxter land between 25 July 2019 and 17 September 2019 (as well as any report in relation to that monitoring). The communications are to include instructions issued by the defendants to MDA in respect of any reports commissioned together with any documents evidencing any communication between the defendants and MDA concerning the process of production of those reports and the disclosure of draft or interim reports prior to a final report.

(b) The defendants are not required to make discovery of Category 21.

1. I will hear from the parties in respect of appropriate orders as to the costs of the appeal.

[1] Plaintiffs, 'Plaintiffs' outline of submissions', filed 15 August 2025 ('Plaintiffs' outline of submissions') [1].

[2] Order of Judicial Registrar Lorenz (Supreme Court of Victoria, 19 May 2025) [3].

[3] Plaintiffs' outline of submissions [1].

[4] Sections 7 and 55 of the Civil Procedure Act 2010 (Vic), O 29 of the Supreme Court (General Civil Procedure) Rules 2025, Liesfield v SPI Electricity Pty Ltd (No 1) [2013] VSC 634; (2013) 43 VR 493, 500 (J Forrest J); Volunteer Fire Brigades Victoria v CFA (Discovery Ruling) [2016] VSC 573, [28]-[31] (J Forrest J).

[5] Plaintiff, 'Amended Statement of Claim' filed 4 August 2023, [10]‑-[11], [13].

[7] First Defendant, 'Defence of the First Defendant' filed 11 September 2023 and Second Defendant, 'Defence of the Second Defendant' filed 11 September 2023, [10] and [13].

[8] Letter exhibited to the plaintiffs, 'Second Affidavit of Dominica Sophia Tannock' filed 14 March 2025, 26.