PILBARA PORTS AUTHORITY -v- MINERAL RESOURCES LIMITED [2026] WASC 53 (27 February 2026)

1. In its statement of claim filed 11 April 2025, the PPA says that, in accordance with the Port Authorities Act 1999 (WA) (Act), on 28 June 2024, its board resolved to levy a port charge, which is described as a channel charge for vessels using the Channel (Channel Charge). On 17 December 2024, the board of the PPA resolved to reduce the amount of the Channel Charge. The PPA has invoiced Mineral Resources the Channel Charge for its vessels which use the Channel and Mineral Resources has refused to pay these invoices.
2. Further and better particulars of the Channel Charge have been sought and given. The PPA says the Channel Charge is a port charge within the meaning of the Act as it is a charge for port services, an access charge, and/or a port due.
3. Mineral Resources has filed a number of defences in the proceedings. At the hearing of this application, its current defence was a further amended substituted defence and counterclaim filed on 18 December 2025 (Defence). In its Defence, Mineral Resources denies the PPA's decision to levy the port charge is valid on a number of grounds.
4. First, the PPA did not have power to make the decision to levy the Channel Charge as it was not a port charge, was not a charge in relation to the PPA's functions under the Act, and was not made in accordance with prudent commercial principles, including because the Channel Charge exceeds the costs incurred by the PPA in maintaining the channel or providing port services to Mineral Resources.
5. Second, the PPA's decision was made for an improper purpose as the Channel Charge does not relate to the PPA's costs in providing port services but is to reimburse Chevron its costs of constructing the Multi‑User Facilities, and to recover these costs from Mineral Resources.
6. Third, in making its decision, the PPA failed to take into account a relevant consideration namely that the Channel Charge was not a port due, an access charge, or charge for port services, and took into account an irrelevant consideration, namely that an express function of the PPA was to recover from users of the Port of Ashburton the cost of the provision of these facilities and services.
7. Finally, the decision is challenged on Wednesbury unreasonableness grounds.
8. Mineral Resources accepts it has not paid the invoices issued by the PPA but denies it has any liability to pay these invoices.
9. In its counterclaim, Mineral Resources seeks a declaration that the PPA's determinations are invalid and void. It also seeks a declaration that cl 11 of the Port Facilities Agreement between the PPA and Chevron (PFA) is void, on the basis that it is an impermissible fetter on the PPA's power under s 37(1) of the Act.
10. The PPA has filed a lengthy reply and defence to the counterclaim, disputing the matters raised by Mineral Resources and denying Mineral Resources is entitled to any relief. Relevantly, for the purposes of this allegation, it says that:

(a) Chevron agreed to surrender the Multi-User Facilities, shipping channel, turning basin, navigational aids and road (Port section) on the terms set out in the 'Related Agreements', including the PFA; and

(b) the PPA was required to ensure access to the Channel was consistent with the 'Wheatstone Access Principles' as well as the Relevant Agreements, which included the PFA.

Should any additional categories of discovery be ordered? Category 2

1. This category seeks discovery of all 'Related Agreements' as defined in the State Development Agreement (SDA) and set out in Sch 5, Part 1.
2. The PPA opposed discovery being ordered of this category on the basis that these documents were not directly relevant to the real issue in the proceedings, namely the validity of the Channel Charge. In its submission, the reference to these documents in its reply and defence to counterclaim are in relation to allegations which, it contends, are not relevant to this issue.
3. Mineral Resources says these documents are relevant because the characterisation of the Channel Charge and what it is for is an issue directly in dispute on the pleadings. I do not accept that submission. This is because it is clear from the pleadings as well as submissions made by senior counsel and counsel for the PPA, that the PPA admits it has levied the Channel Charge as a pass-through (or reflex) of the amount it is required to pay Chevron.
4. That said, it is clear from par 13(d) of the Defence and Counterclaim that Mineral Resources is seeking to characterise the fee the PPA pays to Chevron in support of its argument that the pass-through of this fee is not a charge for port services, an access charge or a port due. In that context, the PPA has specifically pleaded that Chevron surrendered certain assets to the PPA on the terms comprising the 'Related Agreements'.
5. The 'Related Agreements' are set out in Sch 5, Part 1 of the SDA. The Schedule refers to 12 specific documents and then a broader category of miscellaneous easements and licences entered into between each of the PPA, Landcorp, the Minister of Lands with Chevron 'on or after the commencement date (if required)'.
6. In my view, the PPA should give discovery of the 12 specific agreements referred to in Sch 5 of the SDA. While I accept that these documents not relevant to the central issue in the proceedings (concerning the validity of the determination to levy the Channel Charge), I accept that they are directly relevant to an issue raised by the PPA. If this category is limited to these specific documents, I do not consider this will impose a disproportionate burden on the PPA.
7. However, for two reasons, I am not persuaded I should exercise my discretion to require the PPA to discover the broader category of documents referred to in Sch 5, Part 1. First, given the description in the Schedule, I am not satisfied that these documents exist. Second, if these documents do exist, they were entered into after the other documents and, as a result, are unlikely to assist in the proper construction or characterisation of any amounts the PPA has agreed to pay Chevron.

1. This category seeks discovery of all Executive Documents between 2009 and 21 September 2011 relating to the SDA, PFA, the Related Agreements and the obligation under cl 11 of the PFA.
2. By Executive Documents, Mineral Resources is seeking 'all papers, memoranda, minutes and briefing papers (in whatever form) prepared by or for:

(a) the executive committee of the PPA (or equivalent committee that reports to the PPA board);

(b) the PPA representatives responsible for negotiating the SDA, PFA or their variations at the relevant times;

(c) the persons holding executive positions in the PPA; or

(d) the PPA Board.

1. I do not accept that this category of documents is directly relevant to the issues in the proceedings. As set out above, the central issue in the proceedings is the validity of the determinations in June and December 2024 to levy the Channel Charge. I do not accept that any issue is raised in the proceedings in relation to the decision to enter into the SDA, the PFA or the Related Documents.
2. Even if I am wrong in my characterisation of the issues in the proceedings, I still would not have exercised my discretion to order discovery of this category. By this category, Mineral Resources seeks discovery of a wide range of documents over an almost three year period more than 15 years ago. The evidence of Mr Sarandopoulos, the chief financial officer of the PPA, which I accept, is that over this period, the PPA's records for this period are a mixture of hard copy and digital records, and that it would require significant time and effort by the PPA to locate documents falling within this category before they could be assessed for relevance. In my view, this time and effort would be disproportionate and inconsistent with the obligations set out in Order 1 r 4A and r 4B of the Rules of the Supreme Court 1971 (WA) (Rules), notwithstanding the amount that Mineral Resources says is in dispute.

1. This category seeks documents in relation to the decision to levy the Channel Charge. Mineral Resources seeks an order that the PPA discover all 'Executive Documents' whereas the PPA says this should be limited to papers and material prepared for the PPA board.
2. Counsel for Mineral Resources advanced two bases for its contention the broader category of documents should be ordered. First, under the Act, the relevant decision-maker is the PPA (and not just the board). Second, because it challenged its decisions on the basis of Wednesbury unreasonableness, all documents which were constructively before the board were relevant.
3. The PPA denies that any discovery obligation should extend beyond the material before its board. Counsel for the PPA emphasised that the relevant decision challenged by Mineral Resources in these proceedings is the decision of the board of the PPA. On this basis, it says that discovery should be limited to papers and materials prepared for the Board as it is these documents that evidence the surrounding circumstances from which any inference must be drawn.
4. In support of the first basis for the order sought, counsel for Mineral Resources referred to decisions where the decisions of local councils,[3] and by a Minister[4] were the subject of challenge. I did not derive any significant assistance from these decisions as the decision-making processes of these parties are different to that of a board of directors of a corporation, even where that corporation is a statutory corporation.
5. Mineral Resources accepted that at trial, in so far as it contends the PPA's determination was made for an improper purpose, it will be necessary for Mineral Resources to establish that the alleged improper purpose was a substantial purpose and that 'the power would not have been exercised but for the desire to achieve the improper purpose'.[5] The improper purpose must be the operative subjective purpose of the decision-maker at or before the making of the decision which is the subject of the challenge. An inference as to the decision-maker's purpose may be drawn from the surrounding circumstances.
6. In this case, as is clear from the statement of claim filed by the PPA, the relevant decision-maker was the board of the PPA. Given this, in so far as Mineral Resources alleges the determinations were made for an improper purpose, it is the subjective purpose of the decision-maker (in this case, the board of the PPA) that is relevant.
7. However, this is not the only basis on which Mineral Resources challenges the PPA's decision. Counsel for Mineral Resources relied on the view expressed by Hill J in CanWest Global Communications Corporation v Australian Broadcasting Authority that where a ground of objection is that the decision was so unreasonable or irrational that no reasonable decision-maker could arrive at it, regard must be had to the material that was actually or constructively before the decision-maker even if not in fact taken into account.[6] On this basis, counsel for Mineral Resources submitted the obligation of discovery should extend beyond those documents that were directly before the board to include documents which were constructively before it.
8. At the hearing, counsel for the PPA submitted that, in circumstances where a previous plea of Wednesbury unreasonableness had been struck out by the court although no application had been brought in relation to the current pleading, the court could have regard to the question as to whether this defence was arguable in considering whether discovery ought be ordered.[7] The primary difficulty with this submission is that since orders were made to strike out what was par 13(m) of the defence, the pleading has been substantially amended. At this stage, I am not satisfied (without having had the benefit of submissions from the parties) that this contention is unarguable.
9. On this basis, given the challenge to the decision on Wednesbury unreasonableness grounds, I accept that it is appropriate that there be some broader discovery ordered but not to the extent sought by Mineral Resources.
10. It is important to emphasise that the decisions challenged in these proceedings are the decisions by the PPA to levy the Channel Charge in June and December 2024, not the decision to enter into a standstill agreement with Chevron or to enter into a variation of the PFA. As was submitted by counsel for the PPA, it is necessary for categories of discovery to be properly 'tethered to the pleadings'.[8]
11. My preliminary view is that in addition to the documents agreed to be provided by the PPA, an additional category of documents should be discovered by the PPA namely:

All papers, memoranda, minutes and briefing papers prepared by or for the executive committee of the PPA (or equivalent committee that reports to the PPA Board) or by or for a person holding an executive position in the PPA between 1 January 2024 and 31 December 2024 regarding any proposal, recommendation or decision to levy the Channel Charge (as defined in paragraph 13 of the Statement of Claim in CIV 1388 of 2025) including, but not limited to, the considerations taken by the Plaintiff with respect to the characterisation of that charge as a "port charge" within the meaning of that term under the PA Act.

1. However, before making this order, I will hear from the parties as to the date range that I have proposed.

1. This category seeks discovery of the profit and loss statements of the PPA in relation to the Port of Ashburton for the financial years for 2023 - 2025, or an extract of the accounting system which shows this information. The PPA says that its annual reports include its financial statements and provided a link to its annual reports. It is apparent from the link provided that the financial statements for the plaintiff are prepared on a consolidated basis.
2. Mineral Resources says this category of discovery is relevant to the question as to whether the agreement between Chevron and the PPA is a fetter on the PPA's powers under s 37 of the Act. This will require consideration of the nature of the various contracts, the nature and degree of fettering and whether restrictions should be imposed on the remedies available so that the contracts cannot be enforced in a manner which in fact fetter the exercise of the relevant discretion under the Act.[9] In this context, the question of the possible damages that could arise from the breach of the contract in the context of the relevant body is relevant. Mineral Resources says that in considering these questions, it is relevant for the court to consider the financial position of the Port of Ashburton and not just the consolidated group.
3. It is clear from Schedule 1 of the Act that the PPA has the control and management of three ports in addition to the Port of Ashburton. Schedule 6 of the Act sets out some specific provisions that apply to only one of the ports under control of the PPA. At this stage, I accept it may be relevant, in considering whether the agreements with Chevron are a fetter on the PPA's power under s 37 of the Act, to consider this question in relation to the Port of Ashburton alone and not on a consolidated basis. I do not understand there to be any contention that the production of these documents would be a difficult task.
4. On this basis, I am satisfied it is appropriate to order the PPA to give discovery of the documents sought in this category.

1. This category seeks discovery of any other document on which the plaintiff will rely at trial.
2. The issue in relation to this category was primarily one of timing. Counsel for the PPA submitted that this could be dealt with by the trial orders requiring the provision of all documents to be tendered at trial to be included in the trial bundle. In my view, that is not sufficient for two reasons. First, as a matter of principle, I consider that all documents which are sought to be included in the trial bundle should be discovered documents. Second, I do not consider this will provide Mineral Resources (or its legal representatives) with sufficient time to consider these documents and whether any further documents should be included in the trial bundle.
3. In my view, the PPA should provide discovery of this category.

1. For these reasons, I consider that in addition to the categories of discovery agreed by the PPA and Mineral Resources, the PPA should provide discovery of:

(a) the 12 specific agreements referred to in Sch 5 Part 1 of the SDA (amended category 2);

(b) all papers, memoranda, minutes and briefing papers (in whatever form) prepared by or for the board of the PPA within the Second Relevant Dates regarding any proposal, recommendation or decision to levy the Channel Charge (as defined in par 13 of the statement of claim) including, but not limited to, the considerations taken by the PPA with respect to the characterisation of that charge as a 'port charge' within the meaning of that term under the Act (amended category 7);

(c) all papers, memoranda, minutes and briefing papers prepared by or for the executive committee of the PPA (or equivalent committee that reports to the PPA Board) or by or for a person holding an executive position in the PPA between 1 January 2024 and 31 December 2024 regarding any proposal, recommendation or decision to levy the Channel Charge (as defined in par 13 of the statement of claim) including, but not limited to, the considerations taken by the PPA with respect to the characterisation of that charge as a 'port charge' within the meaning of that term under the Act (amended category 7); and

(d) categories 8 and 9.

1. I will hear from the parties as to the orders that should be made to reflect these reasons as well as costs.

I certify that the preceding paragraph(s) comprise the reasons for decision of the Supreme Court of Western Australia.

[1] Cove House Illiquid Investments DAC v YA Global Investments LP [2018] WASC 349 [27].

[2] Webber v Racing New South Wales [2017] NSWSC 685 [21] - [22].

[3] Telstra Corp Ltd v Hurstville City Council [2002] FCAFC 92; (2002) 118 FCR 198 [5].

[4] Cazaly Iron Pty Ltd v The Hon John Bowler MLA, Minister for Resources & Ors.

[5] Re MacTiernan; Ex parte Coogee Coastal Action Coalition Incorporated [2004] WASC 264 [51] citing Perpetual Trustees WA Ltd v City of Joondalup [1999] WASCA 196; Thompson v Randwick Municipal Council (195) [1950] HCA 33; 81 CLR 87, 106.

[6] CanWest Global Communications Corporation v Australian Broadcasting Authority (1997) 24 ACSR 405, 413 cited by Buss J in Cazaly Iron Pty Ltd v The Hon John Bowler MLA, Minister for Resources & Ors [2006] WASCA 282 [90].

[9] Searle v Commonwealth of Australia [2019] NSWCA 127; (2019) 100 NSWLR 55 [114] (Bell P).