Appendix E

The expert evidence process

  1. A key responsibility of the Board of Inquiry was to determine the cause of the McCrae Landslide.15 The Board of Inquiry was to have regard to any extant expert reports relevant to that issue.16

Request for relevant reports

  1. One of the Board of Inquiry’s first tasks was to issue to the Shire and SEW a Notice to Produce seeking, among other things, any geotechnical, geomorphological, engineering or technical reports, or reports including such information, prepared for or received by the Shire and SEW concerning the landslide that occurred on 5 January 2025 and the McCrae Landslide.
  2. Following a review of documents produced in response to those Notices to Produce, it was evident that no expert had yet provided an opinion as to the cause of the 5 January 2025 landslide or the McCrae Landslide. It quickly became apparent that the Board of Inquiry would need to engage an independent geotechnical expert to consider the matter. Darren Paul, Technical Director – Engineering Geology of WSP, was subsequently engaged.

First block of hearings commencing on 7 May 2025

  1. Mr Paul gave evidence of a more general kind at the Board of Inquiry’s first hearing block about preparatory and causal factors for landslides,17 the regulatory framework used by municipalities to control landslides,18 and how landslides are investigated.19
  2. The Board of Inquiry also required the geotechnical engineer engaged by the Shire, Dane Pope of PSM, to attend the first hearing block for cross-examination. Mr Pope was originally engaged by the Shire in October 2023 in relation to legal proceedings brought against the Shire by the owners of 10–12 View Point Road, in respect of the November 2022 landslides.20 Mr Pope had, prior to the first hearing block, prepared a geotechnical factual report concerning the McCrae Landslide.21 Although Mr Pope was briefed on 17 January 2025 to prepare a report addressing, among other things, the cause of the McCrae Landslide,22 he told the Board of Inquiry at the first hearing block that he had not yet been provided with a clear list of questions,23 and would be unable to finalise that report until July 2025.24
  3. SEW had engaged a geotechnical engineer, David Hartley of SMEC, prior to the first hearing block but he was not immediately required for cross-examination. It is convenient to chronicle the Board of Inquiry’s understanding of Mr Hartley’s engagement by SEW prior to the first hearing block:
    1. On 30 April 2025, at the request of the Board of Inquiry, SEW provided the witness statement of Lara Olsen, then Managing Director of SEW. Ms Olsen’s statement stated that SEW had engaged an expert to produce a report concerning the McCrae Landslide and its connection (if any) to a burst water main near the corner of Bayview and Outlook Roads in McCrae.
    2. On 1 May 2025, the Solicitors Assisting the Board of Inquiry wrote to SEW’s solicitors, Thomson Geer, requesting further information about the report. Thomson Geer responded by explaining that Mr Hartley had been engaged by SEW, and had already provided SEW with an interim report, but that this report was the subject of legal professional privilege. Thomson Geer also stated that a finalised version of Mr Hartley’s report was expected to be provided to SEW on 5 May 2025 and that, at that time, SEW would consider whether to waive privilege over the report and provide it to the Board of Inquiry. In accordance with Practice Direction 4, submissions and supporting evidence concerning the privilege claim were requested from SEW.
    3. On 6 May 2025, Thomson Geer provided submissions and affidavit material in support of SEW’s privilege claim, the tenor of which was that Mr Hartley’s expert report was commissioned in anticipation of legal proceedings.
  4. The first hearing block commenced the next day.
  5. On the morning of the second hearing day, SEW informed the Board of Inquiry that it was waiving privilege over Mr Hartley’s report, and produced the report to the Board of Inquiry shortly thereafter.25
  6. By the end of the first hearing block, it was apparent that more time was required by each of the experts to consider the cause of the McCrae Landslide, and accordingly an extension to the Board of Inquiry’s reporting date was requested and granted to 10 September 2025.26

Expert reports, conclaves, and evidence regarding causation and mitigation

Establishment of expert process

  1. Following the first hearing block, the Solicitors Assisting the Board of Inquiry corresponded with Mr Paul and the solicitors for the Shire and SEW about the timing of the expert reports in relation to the cause of the McCrae Landslide.
  2. Informed by that correspondence, on 12 June 2025, the Solicitors Assisting informed Mr Paul, the Shire, SEW, and the State, that all expert reports on causation were to be provided to the Board of Inquiry by no later than 21 July 2025, and that expert reports on mitigation were to be provided by no later than 12 August 2025. The Solicitors Assisting also foreshadowed hearing blocks at which the experts would be required to attend for cross-examination. Relevantly:
    1. one hearing block was to focus on causation with expert witnesses to give evidence concurrently. This would start on or around 4 August 2025 after the experts had attended a private conclave to discuss their opinions and after they had provided a joint report to the Board of Inquiry identifying the issues about which they agreed and disagreed; and
    2. the further and final hearing block was to focus on mitigation with expert witnesses again giving evidence concurrently following a conclave and the production of a joint report. This hearing block would start in the middle of August.
  3. On 17 June 2025, by letter to the Shire, SEW, and the State, the Solicitors Assisting explained that they were creating a central database for the experts to share raw data so that each expert could consider the same evidence while preparing their reports. The Board of Inquiry issued a Notice to Produce to each of WSP (engaged by the Board of Inquiry), PSM (engaged by the Shire) and SMEC (engaged by SEW) on the same date, seeking the raw data the experts had obtained in the course of their work in relation to the November 2022 landslides, the 5 January 2025 landslide and the McCrae Landslide.
  4. On 26 June 2025, the shared expert database was established with the materials produced by each of the experts.
  5. On 7 July 2025, the Solicitors Assisting wrote to each of the experts and requested that an appendix be annexed to their causation reports setting out the documents considered in preparing their respective reports.
  6. On 10 July 2025, the Solicitors Assisting wrote to the Shire, SEW, and the State confirming the following:
    1. the expert reports on causation were due by 21 July 2025;
    2. a conclave regarding causation would take place over 28 and 29 July 2025 at the office of WSP;
    3. a joint report following the conclave was due by 31 July 2025; and
    4. the hearings on causation would proceed over 4 and 5 August 2025.
  7. On 14 July 2025, the Solicitors Assisting again wrote to the experts and requested that they ensure all raw data relied upon be included in the expert database by 2.00pm the following day. In that same letter, the Solicitors Assisting again confirmed that causation reports were to be provided by 21 July 2025.
  8. In addition to the above, the Solicitors Assisting corresponded with the solicitors for the Shire and SEW throughout May, June and July, in particular to enable SEW’s experts access to the exclusion zone set up around the landslide site. For example, the Solicitors Assisting liaised with the Shire and the owners of the properties within the exclusion zone to permit SMEC to access the properties directly impacted by the McCrae Landslide, as well as undertaking drilling and testing of the ground in and around the landslide site. The Solicitors Assisting also corresponded with the solicitors for the Shire and SEW to ensure that they had timely access to documents and raw data generated by the experts. The Solicitors Assisting made it clear that the parties with leave should inform them immediately if they had any difficulty obtaining materials or access to the site so that the Board of Inquiry could expedite the process where possible.
  9. None of the experts informed the Board of Inquiry that they needed more time to prepare their expert reports.

The causation reports, conclaves, and oral evidence

  1. By 21 July 2025, Mr Paul of WSP,27 Mr Pope of PSM,28 and Mr Hartley of SMEC,29 had each provided their causation reports to the Board of Inquiry. Information and data relied upon by the experts in producing those reports was taken from the shared expert database, as well as from field investigations undertaken by each expert at various times. Additionally, Phillip Hitchcock of Australian Environmental Auditors also produced a report concerning hydrogeology on behalf of the Shire.30
  2. On 25 July 2025, four days after the deadline set by the Board of Inquiry, SEW provided an additional technical memorandum from SMEC,31 noting that Mr Hartley would speak to that memorandum during the conclave. No explanation was provided at that time as to why the additional report was late.
  3. On 28 and 29 July 2025, Mr Paul, Stephen Makin (Hydrogeologist of WSP), Mr Pope, Mr Hitchcock, Mr Hartley, and Hugo Bolton (Hydrogeologist of SMEC) participated in a private conclave concerning causation. Following the conclave, Mr Paul informed the Solicitors Assisting that he considered an additional conclave concerning geochemistry ought to be organised.
  4. On 30 July 2025, the Solicitors Assisting wrote to the solicitors for the Shire and SEW proposing a further conclave for a discussion around geochemistry. In response, SEW’s solicitors outlined SEW’s position that, in addition to the experts from SMEC, SEW had engaged Chris Jewell of C.M. Jewell & Associates on the issue of causation, and that he should attend the conclave. Mr Jewell was not referred to in the causation report produced by SMEC on behalf of SEW. The further conclave concerning geochemistry was arranged for 1 August 2025.
  5. On 31 July 2025, 10 days after the date by which expert reports on causation were due, and two days after the conclusion of the causation conclave, SEW produced an amended version of SMEC’s causation report.32 On that same day, the joint expert report on causation was also produced by the experts.33
  6. On 1 August 2025, Mr Paul, Hong Phuc Vu (Geochemist/Geochemical Modeller of WSP), Mr Hartley, Mr Bolton and Mr Jewell participated in the further conclave for a discussion around geochemistry. Following the conclusion of the conclave, SEW’s solicitors wrote to the Solicitors Assisting to advise that an additional expert report would be provided by Mr Jewell on 8 August 2025 (18 days after the due date for expert reports). On that same day, a minute of the conclave was provided by the experts to the Board of Inquiry.34
  7. At 8.46pm on 3 August 2025, the eve of the causation hearings, SEW produced 17 additional documents containing test results from boreholes dug by SMEC which had not previously been provided to the Board of Inquiry. SEW’s solicitors stated that the results had not been produced to the Board of Inquiry earlier due to an oversight. At 10.21pm, SEW produced further results from tests taken by SMEC after its experts had attended McCrae over the weekend. The Board of Inquiry had not been told that such additional testing was taking place.
  8. The hearings into causation were held over 4 and 5 August 2025. Eight experts gave evidence concurrently during those hearings – Mr Paul, Mr Makin, Dr Vu, Mr Pope, Mr Hitchcock, Mr Hartley, Mr Bolton and Mr Jewell. The experts were cross-examined by Counsel Assisting. Counsel for the Shire, SEW, and the State were also given an unrestricted right to cross-examine all experts.
  9. At the beginning of the hearings, SEW’s non-compliance with the expert timetable that had been set was raised. After submissions were heard on this matter, SEW was directed to produce Mr Jewell’s expert report by 10.00am on 8 August 2025.35 As directed, and to his credit, Mr Jewell provided his report concerning hydrochemistry on 8 August 2025.36 Adjustments were also made to the timetable for the submissions of SEW and the Shire due to SEW’s late provision of expert evidence.
  10. On 8 August 2025, SEW provided the Board of Inquiry with its written submissions on causation.37 On 9 August 2025, the Chair extended the time for the Shire to provide its written submissions to 14 August 2025. On 10 August 2025, the Solicitors Assisting confirmed with SEW’s solicitors that SEW would be able to provide reply submissions on causation on a date to be fixed between 15 and 18 August 2025.
  11. On 12 August 2025, the Shire produced an addendum to Mr Hitchcock’s original report,38 presenting Mr Hitchcock’s views of the additional materials produced by SMEC and Mr Jewell’s report. On 13 August 2025, both Mr Paul and Mr Pope produced a memorandum addressing the late evidence produced by SMEC and Mr Jewell’s report.39 Following production of those documents, SMEC provided additional results concerning a raft of tests undertaken between 9 July and 1 August 2025. The Solicitors Assisting provided these additional results to Mr Paul, who produced an additional memorandum on 18 August 2025.40 The Shire’s solicitors informed the Solicitors Assisting that the additional materials did not change the opinion of Mr Pope and Mr Hitchcock, and they otherwise agreed with the comments made by Mr Paul in his memorandum.
  12. The Shire also provided the Board of Inquiry with its submissions on causation on 13 August 2025.41 The Solicitors Assisting immediately provided a copy of the submissions to SEW’s solicitors and confirmed that SEW would need to provide any reply submissions by 18 August 2025.
  13. SEW provided its reply submissions on causation on 18 August 2025.42

The mitigation reports, conclave, and evidence

  1. By 12 August 2025, Mr Paul and Mr Pope each provided their expert mitigation reports to the Board of Inquiry.43 SEW elected not to provide an expert report in relation to this issue.
  2. On 14 August 2025, Mr Paul, Mr Pope and Tim Whelan (Director – Major Projects and Engineering of Whelans Group), a contractor engaged by the Board of Inquiry to cost Mr Paul’s proposal, participated in the private conclave concerning mitigation. On that same day, those experts provided their joint mitigation report.44
  3. On 18 August 2025, the hearing into mitigation took place. Mr Paul and Mr Pope gave evidence concurrently during that hearing. Counsel Assisting cross-examined the experts. Counsel for the Shire, SEW, and the State were given an unrestricted right to cross-examine both experts.
  4. On 22 August 2025, the Shire and SEW each provided submissions on mitigation.45

Appendix E Endnotes

  • 15 Victoria, Victoria Government Gazette, No S 111, 18 March 2025, 1 [2.1], 2 [3.1(a)].
  • 16 Victoria, Victoria Government Gazette, No S 111, 18 March 2025, 2 [3.4(c)].
  • 17 Public Hearing Transcript, Darren Paul, 7 May 2025, 43–51, 78–81.
  • 18 Public Hearing Transcript, Darren Paul, 7 May 2025, 51–78.
  • 19 Public Hearing Transcript, Darren Paul, 7 May 2025, 81–98.
  • 20 Public Hearing Transcript, Dane Pope, 8 May 2025, 125.
  • 21 Public Hearing Transcript, Dane Pope, 8 May 2025, 161–162; Exhibit CA-2, Geotechnical Factual Report on McCrae Landslide – Evacuation Order Area prepared by PSM, 9 April 2025, [MSC.5007.0004.0078].
  • 22 Exhibit CA-13, Second Witness Statement of David Simon, 17 April 2025, CA-13(135) [MSC.5007.0004.0015].
  • 23 Public Hearing Transcript, Dane Pope, 8 May 2025, 167.
  • 24 Public Hearing Transcript, Dane Pope, 8 May 2025, 166.
  • 25 Exhibit CA-27, Multidisciplinary Expert Report on McCrae Landslip Project prepared by SMEC, 5 May 2025, [SEW.0001.0001.0142].
  • 26 Victoria, Victoria Government Gazette, No S 295, 11 June 2025.
  • 27 Exhibit CA-67, McCrae Landslide Causation Report prepared by WSP, 21 July 2025, [DPA.0004.0001.0001].
  • 28 Exhibit CA-71, McCrae Landslide Causation Report prepared by PSM, 21 July 2025, [MSC.5087.0001.0157].
  • 29 Exhibit CA-68, Multidisciplinary Expert Supplementary Report on McCrae Landslide prepared by SMEC, 21 July 2025, [SEW.0001.0002.4187].
  • 30 Exhibit CA-73, Expert Hydrogeological Report prepared by Australian Environmental Auditors, 21 July 2025, [MSC.5087.0001.0001].
  • 31 Exhibit CA-70, Technical Memorandum concerning Geochemical Analysis of Groundwater Provenance prepared by SMEC, 25 July 2025, [SEW.0001.0002.4197].
  • 32 Exhibit CA-69, Revised Multidisciplinary Expert Supplementary Report on McCrae Landslide prepared by SMEC, 30 July 2025, [SME.0001.0001.0501].
  • 33 Exhibit CA-74, Joint Report about causation prepared by expert conclave, 31 July 2025, [INQ.0009.0001.0001].
  • 34 Exhibit CA-75, Joint Report about geochemistry prepared by expert conclave, 1 August 2025, [INQ.0010.0001.0001].
  • 35 Public Hearing Transcript, Chairperson, 4 August 2025, 1066.
  • 36 Exhibit CA-84, McCrae Landslide Geochemistry Report prepared by C.M. Jewell & Associates, 8 August 2025, [SEW.0001.0002.4199].
  • 37 Submission of South East Water about the causes of the McCrae Landslide, 29 July 2025, [SEW.0001.0002.4201].
  • 38 Exhibit CA-85, Expert Hydrogeological Report Addendum on McCrae Landslide prepared by Australian Environmental Auditors, 11 August 2025, [MSC.5088.0001.0001].
  • 39 Exhibit CA-88, Assessment of additional information provided by South East Water between 21 July 2025 and 8 August 2025 prepared by WSP, 13 August 2025, [DPA.0006.0001.0001]; Exhibit CA-89, Response to SMEC Submissions prepared by PSM, 13 August 2025, [MSC.5090.0001.0001].
  • 40 Darren Paul, WSP, Assessment of additional information provided by South East Water on 14 August 2025, 18 August 2025, [DPA.0007.0001.0001].
  • 41 Submission of the Mornington Peninsula Shire Council about the causes of the McCrae Landslide, 13 August 2025, [MSC.5095.0001.0001].
  • 42 Reply Submission of South East Water about the causes of the McCrae Landslide, 18 August 2025, [SEW.0001.0002.4202].
  • 43 Exhibit CA-87, McCrae Landslide Remediation and Mitigation Report prepared by WSP, 12 August 2025, [DPA.0005.0001.0001]; Exhibit CA-86, McCrae Landslide Mitigation Report prepared by PSM, 11 August 2025, [MSC.5088.0001.0007].
  • 44 Exhibit CA-90, Joint Report about remediation and mitigation prepared by expert conclave, 14 August 2025, [INQ.0012.0001.0001].
  • 45 Submission of Mornington Peninsula Shire Council about mitigation of further landslides, 22 August 2025, [MSC.5094.0001.0050]; Submission of South East Water about measures to reduce or prevent the risk of another landslide, 22 August 2025, [SEW.0001.0002.4205].

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