Aymost Pty Ltd v State of New South Wales; Hecher v State of New South Wales

[2004] NSWSC 1309

CITATION:	Aymost Pty Ltd v State of New South Wales & Ors; Hecher & anor v State of New South Wales & Ors [2004] NSWSC 1309
HEARING DATE(S):	12/07/04 - 14/07/04 inclusive
JUDGMENT DATE:	2 December 2004
JURISDICTION:	Common Law
JUDGMENT OF:	Michael Grove J at 1
DECISION:	See pars 114-115
CATCHWORDS:	THREDBO LANDSLIDE - JOINT HEARING OF CLAIMS FOR "COMMERCIAL" LOSSES - DETERMINATION OF SEPARATE QUESTIONS RELATING TO THE CAUSES OF THE LANDSLIDE
LEGISLATION CITED:	s110K Supreme Court Act 1972
PARTIES :	Aymost Pty Limited trading as House of ULLR & ors v State of New South Wales & Ors; Bernd Josef Hecher & Patricia Frances Hecher v State of New South Wales & Ors
FILE NUMBER(S):	SC 20950/99; 20138/03
COUNSEL:	L. Robberds QC with T. Alexis SC (Plaintiffs) P.R. Garling SC with S.A. Gregory and C.A. Webster (Defendants)
SOLICITORS:	Rockliffs (Plaintiffs) Frances Allpress (Defendant)

IN THE SUPREME COURT
OF NEW SOUTH WALES
COMMON LAW DIVISION

MICHAEL GROVE J

Thursday 2 December 2004

20950/99 – AYMOST PTY LIMITED trading as HOUSE OF ULLR & ORS v STATE OF NEW SOUTH WALES & ORS

20138/03 - BERND JOSEF HECHER & ANOR v STATE OF NEW SOUTH WALES & ORS

INTERLOCUTORY JUDGMENT ON SEPARATE QUESTIONS

1 HIS HONOUR: On 30 July 1997, a landslip or slide occurred under the northern aspect of the Alpine Way, a road passing by habitations in the approximate southeasterly quadrant of Thredbo Village. It caused the destruction of two lodges and the loss of lives of occupants. Those lodges stood upon a slope descending towards the Thredbo River which courses along the bottom of a valley. The upper or southernmost of these lodges was Carinya which was subleased to Brindabella Ski Club and the lower, named Bimbadeen, was a “staff” lodge of the head lessee, Kosciusko Thredbo Pty Limited. The whole village lies within the Kosciusko National Park and the lessor is the National Parks and Wildlife Service.

2 The tragedy of the lost lives (and the rescue of a sole survivor in one lodge) is notorious and the disaster has taken its place in widely known history. An extensive coronial inquest was held and it is important at all times to distinguish that inquiry from the task presently being undertaken, namely the determination of civil litigation between parties. As is always the situation, findings in litigation inter partes are made upon the evidence which the disputants have chosen to put before the court. Although the volume of such evidence in this instance can be inferred to be similar in many respects to that which must have emerged in the inquest, I have not conducted an investigation and conclusions which I express, for example concerning the cause(s) of the landslide, should be understood as being made in the limited context of the issues in this civil litigation. There is no legitimate basis for comparison or contrast between the inquest findings and any findings in this litigation.

3 From time to time, about forty claimants participated in proceedings seeking awards of damages compensating them for losses alleged to have been caused, directly or indirectly, by the landslide. For reasons which need not now be explored, the number of continuing litigants fluctuated but eventually some thirty four claims were gathered for concurrent hearing. The substantial majority of these claims (but not all of them) sought recompense for financial losses to commercial operators, particularly losses said to have arisen out of the restriction upon access to the village during rescue, restoration and rehabilitation operations.

4 By their pleadings, not all claimants sued the same defendants although it was common to every case that the State of New South Wales (and/or its instruments, incorporated or unincorporated) was a defendant. In the light of what has now occurred it is not necessary to detail individual claimants, the respective opponents nor the more than sixty cross claims spawned by the litigation.

5 Interlocutory rulings directed, inter alia, to establishing a manageable hearing included an order for initial determination of a separate series of questions focussed largely upon the cause of the landslide. There was some contest between the numerous parties as to the draft of appropriate questions and a ruling was made specifying those which would be put to issue. This ruling was made on 19 March 2002 and the final formulation had essentially been derived from two particular drafts and, although recognizing that there was potential for some overlap, a scheduled hearing commencement date of 15 April 2002 was maintained.

6 During the hearing, the issue of question formulation was again raised by motion and some amendments were made pursuant to a ruling given on 27 September 2002. As then amended, those remain the relevant questions. It will be necessary to deal in particular with two entities referred to in the questions as either the “pipeline” or the “water main” and either the “Winterhaus Corner retaining wall” or the “Winterhaus retaining wall” or similar. The questions posed are as follows:

“1. Was the landslide caused solely, or materially contributed to, by water which came from one or more fractures or leaking joints in the pipeline?

2. Was the landslide caused solely, or materially contributed to, by water which came from additional flows, if any, resulting from the construction of the Winterhaus Corner retaining wall?

3. Was the landslide caused, or materially contributed to, by both of the causes set out in paragraphs 1 & 2 above?

4. Was the landslide caused, or materially contributed to, by part of the slope above and to the south west of Carinya being poorly compacted, overly steep, marginally stable or vulnerable to a small elevation in either the groundwater table or groundwater pressure? If so, which part of the slope and which of those causes?

5. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of creep in the fill?

6. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of the direct or indirect impact of construction activity associated with the construction of the retaining wall?

7. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of the direct or indirect impact of construction activity associated with the resurfacing of the Alpine Way?

8. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline was that leakage caused by more than one of the causes set out in paragraphs 5, 6 & 7 above? If so, which of those causes?

9. If the landslide was caused, or materially contributed to, by water which leaked from one or more fractures or leaking joints in the pipeline, was the pipeline inappropriately located, designed, constructed, approved, operated and/or maintained?

10. If the landslide was caused, or materially contributed to, by water which came from additional flows resulting from the construction of the Winterhaus Corner retaining wall, was the Winterhaus Corner retaining wall inappropriately designed, approved and/or constructed?

11. Which acts or omissions, if any, were responsible for the operative cause or causes of the landslide set out in paragraphs 1, 2, 3 & 4 above, and to what extent?

12. Was the Thredbo landslide caused by:

(a) the marginal stability of the slope above Carinya;
(b) the existence and state of the Alpine Way;
(c) the omission to improve the stability of the slope above Carinya (including the Alpine Way) in accordance with acceptable standards and accepted practice, before the landslide;
(d) infiltration from the Winterhaus retaining wall drainage trench;
(e) leakage from the water main; or
`(f) a combination of (a) (b) (c) (d) and/or (e) and if so, the extent of each cause.

13. If the Thredbo landslide was caused by leakage from the water main or such leakage contributed to the landslide, was the cause of such leakage:

(a) construction activity associated with the construction of the Winterhaus retaining wall;
(b) construction activity associated with the resurfacing of the Alpine Way following construction of the Winterhaus retaining wall;
(c) soil creep; or
(d) a combination of (a) (b) and/or (c), and if so, the extent of each cause.


14. Was the slope above Carinya, and in particular the Alpine Way, designed, constructed, maintained and monitored in accordance with acceptable standards and accepted practice.

15. If the water main leaked, in a way that caused the landslide, did it do so by reason of the fact that it was located, designed, approved, constructed and/or maintained following construction, other than in accordance with accepted standards and accepted practice.

16. If there was infiltration from the Winterhaus retaining wall drainage trench, in a way that caused the landslide, did it do so by reason of the fact that the Winterhaus retaining wall was designed, approved, constructed and/or monitored following construction, other than in accordance with acceptable standards and accepted practice.

17. Was the geotechnical advice from the RTA to the NPWS from August 1991 until the landslide, advice that a reasonably competent geotechnical engineer would have provided during that period in relation to the stability of the slope above Carinya? If not, what advice would a reasonably competent geotechnical engineer have provided to NPWS, in relation to the stability of the slope above Carinya, during that period?”

7 The hearing proceeded in stages; the vast bulk of evidence being in the nature of expert opinion concerning the addition of water to a natural groundwater table causing the latter to rise and thus “triggering” the landslide. This subterranean water addition was designated to derive from an “unnatural” source. A perceptive comment by counsel was that the answers to the postulated questions should become evident upon determination of one fundamental question: Where did that water come from?

8 There is substantial dispute between experts as to what the answer to that simply stated question should be. This comes as no surprise. Although neither the evidence received by the coroner nor his finding is in evidence in this litigation, it was common ground that as an adjunct to the coronial inquiry there was held a “convocation of experts” and that there did not emerge therefrom unqualified agreement as to the cause or causes of the landslide.

9 However, on 7 March 2003 (by which date the hundredth day of hearing for determination of the separate questions had been passed) senior counsel appearing for the State interests (the State of New South Wales, the Roads & Traffic Authority (RTA) and the National Parks and Wildlife Service (NPWS) sought reference to the whole balance of proceedings for mediation pursuant to s 110K of the Supreme Court Act (T6248). Over the next several months mediations took place with the consequence that all claims (including all cross claims) save one were resolved.

10 The continuing plaintiffs are Mr and Mrs Hecher. They conducted a business in the form of a commercial lodge (Bernti’s Mountain Lodge) erected on land subleased from Kosciusko Thredbo Limited. The lodge was not physically damaged by the landslide. They originally joined as plaintiffs with others who sued the State of New South Wales, the RTA and Lend Lease Corporation as defendants. The firstnamed plaintiff in that action was Aymost Pty Limited trading as House of ULLR (another lodge). That action (20950/99) can conveniently be referred to as “the Aymost action”. Although Lend Lease Corporation is a defendant in that action, it has not participated in the continued hearing of the Hecher claim, no doubt in accordance with the resolution of its disputes with the State interests.

11 In the initiating process the claims of all the plaintiffs in the Aymost action were particularized and itemized under general headings of “lost profits”, “consequential losses”, “review of village risk assessment” and “coronial inquiry.”

12 Subsequently the statement of claim was amended to include a claim by Mr Hecher for injury to his person. Thereafter Mr and Mrs Hecher notified a desire to be no longer represented by the solicitors acting for all the other plaintiffs in the Aymost action. It was perceived that there might be procedural difficulties in severing themselves from that action and effecting a change and on 30 May 2003 a further statement of claim was filed and served on their behalf as sole plaintiffs by new solicitors. These solicitors had in fact been acting for other plaintiffs not joined in the Aymost action. On behalf of those plaintiffs they had been fully involved in the hearing for determination of the separate questions. In this latest action (20138/03) the State of New South Wales, the Minister administering the National Parks and Wildlife Act 1974 and the RTA were named as defendants.

13 This action pleaded by way of damage that Bernti’s Mountain Lodge, by reason of the landslide, was assessed as being exposed to high risk of instability, was immediately vacated and was later re-assessed as being exposed to a medium risk of instability. Thereupon the plaintiff (Mr) Bernd Josef Hecher “became exposed to severe emotional and financial stress that caused a right cerebella(r) haemorrhage stroke on 14 September 1997 and a severely debilitating pontine stroke on 21 October 1997”. As I stated at the outset the landslide had occurred on 30 July 1997.

14 Further particulars of alleged losses sustained by the Hechers referred to payment of $20,000 premium to Kosciusko Thredbo Limited for the sublease (pursuant to an agreement of 27 January 1978) and the costs of construction of the lodge and its refurbishment from time to time. Also particularized was the purchase (in 1988) of 247 acres of land in the Thredbo Valley. I infer from the description “purchase” that this property is outside Kosciusko National Park. Buildings were erected on this land and after 1993 a business known as Bernti’s Emu Ground and “related farming activities” were said to be conducted there. Other particulars, expressedly incomplete, specify costs and expenses relating to finance, insurance and associated matters, costs and expenses relating to consultants and professional advisers incurred since the landslide. Claim is also made for the personal disabilities of Mr Hecher consequent upon his strokes.

15 I am not, of course, presently embarked upon the trial of any issue relating to damage but it would be less than candid if I did not record my impression that, of the multiple plaintiffs alleging losses suffered as a consequence of the landslide, the failure of only Mr and Mrs Hecher’s claims to be resolved by mediation is likely to be sourced in the ambit of their claims as particularized. It is not appropriate to comment now upon the apparent remoteness of some aspects of the claims.

16 It is necessary to examine to some extent how the hearing has been conducted. All parties consented to the evidence called by other participants being evidence in their individual actions. The original head lease of the village area was granted to a subsidiary of Lend Lease Corporation named Kosciusko Thredbo Limited. This has been referred to as KT1. In 1987 the head lease was assigned to a new lessee, which, after KT1 was wound up, acquired the same name. This second Kosciusko Thredbo Limited was referred to as KT2.

17 I interpolate that it follows that the initial sublease of what became Bernti’s Mountain Lodge was between KT1 and Mr and Mrs Hecher.

18 The first substantial body of evidence on behalf of plaintiffs was called by representatives of KT2. In particular this included extensive expert evidence. Other representatives of various plaintiffs called witnesses and tendered documents. From time to time, witnesses were interposed “out of order” but nothing turns on this.

19 In due course the plaintiffs closed their cases. Of significance is the closure of the case brought by Rarida Pty Limited, trading as the Winterhaus Lodge (and others) announced by its solicitor Mr S. Rockliff on 24 October 2002 (T4351). Mr Rockliff’s firm is now retained to pursue the remaining claim by the Hechers. As earlier mentioned, this firm did not act for the plaintiffs (including the Hechers) joined in the Aymost action.

20 After the closure of the plaintiffs’ cases, evidence was called on behalf of the defendant State interests. Their cases were, subject to minor matters not now relevant, closed on 7 February 2003 (T5791). Next, evidence was commenced to be called on behalf of Oxbara Pty Limited, trading as Rye’s Plant Hire, a corporation involved in the erection of the Winterhaus retaining wall. The evidence being called on its behalf was interrupted by the application to refer all matters to mediation. There matters stood, so far as evidence was concerned, until the eventual reported success of mediation of all claims except that brought by the Hechers.

21 In accordance with the Rules of Court and directions given, expert reports in relation to intended evidence had been served on all parties. For present purposes it can be noted that reports from experts in a variety of fields had been served on behalf of Lend Lease Corporation, the liability of which as a defendant or cross defendant, was asserted to be derived from the activity of its now defunct subsidiary KT1. KT1, inter alia, had been responsible for the installation in 1984 of the water pipeline.

22 The resumption of hearing for the continuation of the claims by Mr and Mrs Hecher was accompanied by a motion to permit them, either by way of reopening their case or in the nature of reply, to call evidence foreshadowed in the report served on behalf of Lend Lease Corporation as well as some further evidence then identified. On 27 October 2003, for reasons then given, I dismissed the motion. There is no need to repeat the content of the judgment on the motion then published and to the extent that it may be relevant, it may be treated as incorporated herein.

23 I should relate some further general background which needs to be understood to give context to the dispute between the parties as to the appropriate answers to the questions.

24 Although not compass precise, I will adopt premises that the valley lies on an east-west axis and the slopes are to the north (Mount Crackenback) and to the south. The Alpine Way runs along the southern slope traversing from the east (Jindabyne) towards the west (Dead Horse Gap).

25 The dominant physiographic feature of the valley is a deeply incised fault plane along the base of which the river flows in an easterly direction. The valley has formed over geologic time. The area is substantially comprised of substance of late Silurian age (410 to 420 million years) known as Mowamba granodiorite. This was described as typically a medium to coarsely crystalline biotite granodiorite, containing various dykes and veins and metasedimentary xenoliths. In decomposition, layers were identified of extremely weathered granodiorite (EWG) and highly weathered granodiorite (HWG). Granodiorite is granitic rock, the mineralogy of which is transitional between granite and diorite. Other content included gravelly silty sand, clay zones and others. It is not necessary to analyse the geology of the whole area.

26 Into this valley an access track which came to be known as the Alpine Way was constructed for the purpose of the Snowy Mountains Hydro Electric Scheme. The construction was achieved by driving a path using machinery such as bulldozers and side casting removed material, including organic matter such as tree trunks. The construction took place in about 1955 and there was some “upgrading” in 1958.

27 About that period entrepreneurs became interested in establishing snow ski runs and an associated resort which, through negotiations with governments of the day and their instrumentalities, led to the lease and development of what became known as Thredbo Village. No issue in the litigation turns upon any opinion as to whether the apparent replication of a European style ski resort in the Australian bush was or was not a flawed concept. The evidence that this ancient area had a history of, and potential for further, landslip was however overwhelming.

28 The Alpine Way was, and is, the only road access to the village.

29 For the purposes of the litigation the defendants admitted the following facts:

“The fill embankment beneath and downhill of the pavement of the Alpine Way was marginally stable in places as a result of one or more of the following:
(a) poorly compacted fill;
(b) the steepness of the fill and natural slope;
(c) debris in the fill;
(d) the depth of the fill; and
(e) the high ground water table.
The slope above Carinya was marginally stable, vulnerable to adverse changes in ground water and sloped in the order of 35-45 degrees.”

30 The landslide was, in substance, a collapse of the slope above Carinya.

31 It is the plaintiffs’ case that the primary cause of the landslide was the marginal stability of the fill in the embankment above Carinya. Breach of duty of the defendants is asserted to derive from failure to improve the stability “by engineering means, in accordance with acceptable standards and accepted practice.” A secondary cause is submitted to be infiltration of “unnatural water” causing a rise in the ground water table which occurred because the Winterhaus retaining wall was inappropriately designed and constructed. The plaintiffs do not contend that the ground water table was raised by water leaked from the pipeline.

32 In support of the primary contention, the plaintiffs refer to an immense amount of documentation (tendered at the hearing by Rarida) which appears to attempt to collate all of the history of the Alpine Way as well as all the information which an instrumentality such as the RTA did or could access concerning risks of landslide above or below roadways. The same collation includes documents relating to the Winterhaus wall and the water main.

33 Whilst I recognize the primary position taken on behalf of the Hechers, it can be observed that a huge proportion of the hearing time (witnesses and associated documentation) was directed to the dispute about the source of unnatural water. Hence counsel’s pithy observation above recounted. The initial and unchanged position of the defendants was that this source was a leak, or a leak consequent upon fracture of, the water main and that the rise in the ground water table was not relevantly affected by the installation of the Winterhaus wall. The principal experts on both sides of the litigation (Drs. Redman and De Ambrosis) agree that the landslide was “caused” by introduction of unnatural water to the slope south west of Carinya.

34 I should describe the particular entities. I turn first to the pipeline.

35 A water reticulation system passes around and through the village. Included in the system are major storage tanks on the northern slope of the village (High Noon tanks) and the south (Alpine Way tanks). There is also a set of tanks near a golf course in the valley area. Gravity pressure is assisted by pumping facilities including one located at Bimbadeen. The system is such that flow may occur in either direction.

36 In 1982 KT1 obtained a report from Technical Risk and Insurance Management Pty Limited (TRIM) which included a focus upon water supply. With particular reference to fire risk it was reported that water supply to sprinklers and hydrants around the hotel and valley terminal (operated by KT1) were inadequate and liable to freeze in winter. Various recommendations were made.

37 By letter dated 9 November 1982 the Board of Fire Commissioners wrote to KT1 and included this comment:

“5. A fire main and hydrant should be installed on the Alpine Way above the village to provide a source of fire fighting water for nearby lodges and to combat bush fires on the east side of the road.”

38 At a meeting on 13 December 1983 Mr Van der Lee, an officer of KT1 (and incidentally at one time a cross defendant joined by the State interests) advised a meeting of KT1 and NPWS officers of the intention to install a ring (water) line on the north side of the Alpine Way during that summer.

39 Work was underway in April 1984. It was stopped owing to an absence of approval. On 5 April 1984 Mr McConnell, the resort engineer of KT1 applied to the NPWS for approval. The letter bears a “receipt” stamp of the same date. The text includes:

“Please find enclosed for your combine development/building approval three copies of drawing No 84/1 showing hydrant works to protect the upper lodges along the Alpine Way.
This work has been recommended to us by Technical Risk and Insurance Managers Pty Limited who advise us on potential risk matters.
The DMR have already been approached and have walked the proposed line with us indicating the pipe should be approximately 2 metres from the existing road shoulder and at least 600 mms below the surface.”

40 The DMR is of course the predecessor of the RTA and no distinction between them need be drawn.

41 A copy of the drawing referred to bears an “approved project” stamp of NPWS dated the following day 6 April 1984. I would describe the drawing as skeletal and the evidence does not disclose any more detailed pre construction plan. An accompanying letter also dated 6 April from NPWS to KT1 included:

“4. The works shall be carried out to the satisfaction of the District Building Inspector. Particular emphasis shall be placed on the consolidation of backfill along the top bank of the road. The area below is a slip zone and build up of water in a soft trench could increase the risk of movement.
5. Consolidation and compaction to 100 percent shall be attained (Standard road test).”

42 The pipeline was built substantially of 100 ml asbestos cement portions, jointed in a manner which I shall describe, and formed a ring out of the extant reticulation system from near Banjo Drive (an intersection at the western end of the ring), passing under the northern unsealed verge of the Alpine Way until it turned north down the slope to the west of Carinya, rejoining the system at the Bimbadeen pumps.

43 Evidence concerning the actual construction is scanty (I set to one side for the moment conclusions made from observations after the landslide) but there is a manuscript memorandum of 10 May 1984 from the NPWS Building Inspector to Mr McConnell stating:

“We request that the 100 mm AC water main be bedded in sand, and backfilled with sand to 100 mm above the pipe or other suitable material.
Present excavated material is not suitable, too many large boulders present, unless boulders are removed.”

44 A final record appears to be a copy internal memorandum of KT1 dated 12 June 1984 signed by Mr McConnell containing references to “TRIM Works” and “Water Supply Installation” and “Complete”.

45 As mentioned the lease to KT1 was assigned. Necessary consent was given on 5 January 1987 and the assignee was Greenfields Development Company Pty Limited which became KT2. It was a condition of assignment that prior to winter 1987, KT2 would carry out a check survey. This revealed that some of the “Fire Main Works” (specifically part of the pipeline) lay outside the area of demise. A supplemental deed of 25 September 1990 incorporated the relevant area within it.

46 In order to examine allegation of leakage from the pipeline it is necessary to understand how it was designed to function with particular reference to the coupling arrangements pertinent to the pipe barrels.

47 As stated above, the pipeline was constructed as a ring to the mains system. Its essential components were barrels of asbestos cement (AC) of standard four metre lengths. A length could be cut if necessary. The internal diameter was 100 mm and the wall thickness a little over 12.5 mm. Each end of the pipe length was machined in order to facilitate entry into the coupling (spigot) and the edge at the ends was bevelled (chamfer).

48 The barrels were joined in couplings made of shorter lengths of larger diameter AC, the inner diameter of which was machined to house two V ring rubber seals. The chamfers of connecting pipes did not meet within the coupling but the wedge shapes of the seal received water under pressure thus rendering it effective. There are numerous sketches of the system in the documentary evidence.

49 The ideal distance into which the spigot should be inserted into a coupling was discerned by a witness mark which was a groove cut into the circumference of the spigot. The system would tolerate some “pullout” of the barrel and (absent break or fracture) leakage should not occur until the sealing effect of a V ring has been compromised.

50 There is no comprehensively detailed plan of the ring main. Portions destroyed in the landslide (or any remnants of them) were not evidenced as having been examined, nor have they been preserved. The lost portions were in the area following the descent at the west of Carinya and leading to the join at the Bimbadeen pumps. Photographs show the “snapped” pipe ends at the upper and lower extremes. The surviving upper end follows the generally west to east path of the Alpine Way. It can be deduced that the pipeline must have “turned” to the north in order to descend and this could be achieved by construction of either a single 90 degree bend or two 45 degree bends. Other combinations are possible but highly unlikely. For the reasons given by Dr De Ambrosis in particular (he supervised exhumation of some of the upper pipe remnants) I consider the latter more likely. To achieve this turn, reasonably competent construction requires concrete anchor blocks (or a block) to engage the line. Similar blocks, sometimes referred to as thrust blocks can be used at other points along it.

51 To create a frame of reference the first joint to the east of the upper pipe end (which was not, as I have indicated, recovered) was designated Joint 0, and each joint into which spigots were inserted to the west enumerated Joint 1, Joint 2, Joint 3 and so forth. Reference to Joint 0 should be elaborated. If two 45 degree bends are postulated, Joint 0 is the first of these and there is presumed an “intermediate” joint before the next 45 degree bend. If a 90 degree bend is postulated Joint 0 is located between it and Joint 1. In either event Joint 0 is, as I have said, the first joint east of Joint1.

52 The joinder of Joints 1 and 2 was not standard in the sense that it was, rather than AC pipe, an 11¼ degree cast iron bend associated with the couplings. I am satisfied that the probable explanation for this is that the initial construction of the pipeline started from both ends where it joined the main system and a slight deviation was necessary to unite the separately advanced sections when they reached each other.

53 The pipeline was exhumed from the upper fracture surface at the landslide scarp up to Joint 5. Portions of this activity were captured on video film. By reference to its witness mark, and confirmed by later extraction, the eastern spigot of Joint 1 was withdrawn beyond the effect of the rubber V ring seal. I am satisfied that the pipeline had leaked from that point. Whether that was the case for a long or short time before the landslide or only after being pulled apart by significant land movement just before or during the landslide itself are matters of debate. I should also mention the contested postulation that there was likely leakage (pre landslide) from some part of the pipeline to the east and/or north of Joint 1.

54 Inspection showed that the cast iron segment had become fixed in a sealed situation. The witness marks at Joint 3, 4 and 5 established that the pipe spigots were in good position and I am satisfied that there were no leaks from those points. During the night of July 30-31, the supply of water to the ring (now partly demolished by the landslide) was shut off. It is not known (the system having some self governing mechanics) whether at the time of the catastrophe the flow was towards or from the Bimbadeen pumps. Later the pipeline was cut and sealed to the west of Joint 5 and a service to some adjoining lodges apparently maintained. Disconnection and those steps ensured that thereafter there was no material contribution from the pipeline water into and through the landslide scarp. There was a need for repair to the west subsequently but I do not consider this could have contributed to the occurrence of the slide itself.

55 So far as the exhumation revealed, the pipeline was embedded in sand backfill although there were pockets of decomposed soil and approximately 6mm aggregate towards the eastern end of the surviving upper line.

56 The above relates to the situation regarding the pipeline generally. It may be necessary in dealing with arguments concerning the inculpation or non inculpation of it as a cause of the landslide to consider other particular observations, for example, the so called delta near the top of the scarp, the incompleteness of cement anchor or thrust blocks, moisture in a post hole in a car park under which the pipeline ran, absence of or probability of surface venting of water at various locations, wet areas and dry areas, including drying out of the landslide scarp. However, as I repeatedly stated during the hearing, the issues in litigation did not involve the equivalent of a commission of inquiry into every detail surrounding the landslide event.

57 The contested issue concerning subterranean water is complicated by the undeniable fact that after the landslide a considerable volume of water was discharged from the broken pipe. True, this was a discharge onto the surface and it might be postulated that most water (from either “snapped” end) would flow down into the river at the base of the valley but it could be expected that some of it would be absorbed into the ground. I accept the evidence of Mr Cocks that when he arrived in the morning after the landslide, the holding tanks in the system had been emptied.

58 I turn to sketch some matters pertaining to the Winterhaus retaining wall. Much of this is extracted from various memoranda and documentation contained in NPWS files. There was a “blind” corner where the wall was to be eventually erected and it was desirable to cut the embankment to remove associated risks to traffic. There was also a desire to relieve congestion in and about the car parks adjacent to the lodges and the Alpine Way. This was particularly a problem during snow clearing operations.

59 The topography included the presence of a spring or watercourse emerging in the southern slope above the Alpine Way. The lodge immediately to the west of Carinya was known as the Schuss Lodge and this watercourse generally referred to as the Schuss Spring. There was also a swampy area in the embankment between Carinya and the Alpine Way. The relevance was that these existences provided signals that water flow, above and below ground, would need to be taken into account in designing and carrying out the works.

60 As revealed in some respects by post landslide excavation and inspection there were in existence old drains, drainage courses and culverts. The original bulldozed track had been surfaced and resurfaced. Detail of these features was examined at length at the hearing but the examination merely provided focus upon some of the many factors which were argued to support or contradict the proposition that building the wall added unnatural water to the groundwater table.

61 A design and plan for the wall was prepared by Mr Roger Ubrihien (at one time a party to the litigation). Much criticism was directed to his efforts by the plaintiffs. Little point would be served in recapitulating this criticism which at no time seemed to address the scale of what was involved. The works were principally directed to removing a possible traffic hazard on a minor road (in the overall State highway system) near a small village in a national park. It would not be reasonable to expect the production of planning material such as might be appropriate for a major project such as the construction of an expressway or a cross city tunnel.

62 The design recognized the need to drain both surface and underground water and, despite the relatively minor nature of the works, a study and significant report (Review of Environmental Factors by Mr R. Gibbs) was prepared in January 1994. This review confirmed the need to pay attention to drainage during construction and concluded that building the wall would have minimal environmental impact and that construction should therefore go ahead.

63 Construction commenced on 5 February 1997 and was concluded on 25 March 1997. The work was contracted by Rye’s Plant Hire abovementioned.

64 The design documentation consisted of two sheets which can conveniently be seen in Exhibits State 54A and B. The wall consisted of concrete panels slotted between I bars which had been driven into the earth. The vertical bars are so described because, viewed in cross section, they resemble a capital letter “I.” The panels were sized so as to create a tapering downwards of the wall at the ends. I do not need to describe what can be seen in photographic exhibits. Between the cut embankment and the wall was a crushed rock fill and drainage was to be achieved by a system of pipes shown on the sketch. I note that the plan provided for a facing in front of the concrete panels but this facing was not put in place. It was purely cosmetic and nothing turns upon its absence.

65 It appears beyond dispute that, in the event, the contractor did not build the wall exactly to what might be understood from the plans, if that be an appropriate description of the two documents. A prominent criticism of the construction can be found in the evidence of Mr Philip Glasby but his opinions, and the extensive investigation of the drainage system, the drainage trench and a myriad of detail relating to them require no more than an essential determination of whether or not the wall, as constructed, diverted subterranean water to a groundwater table causing a rise which in turn precipitated the collapse of the embankment above Carinya.

66 Because, I infer, the opinion that this was the case had been mooted, the wall was eventually deconstructed. Again this provoked examination of minute detail which is relevant only to the extent that it enables answers to be given to the questions posed.

67 It would seem therefore a practical approach to consider first the opposing contentions concerning the source of “unnatural” water.

68 As indicated already, there were only two “candidates” argued to be possible sources, the water main and the disruption caused by the Winterhaus wall construction. It is something of an understatement to say that they were the subject of evidence. The minutiae in connection with their location, construction and operation were extensively canvassed. The exercise extended so far as to call experts on the inherent qualities of asbestos cement piping, the material of which the pipeline was constructed. It is convenient to mention some other experts. There was evidence of the undertaking of computer modelling. This was utilized by various experts and performers of such activity were called. Whilst such modelling can no doubt confirm the feasibility of a theory advanced by an expert, it is a necessary observation that the modelling is done upon facts assumed for the purpose of the model. Some of these “facts” were said to be derived from observation but others from deduction and selection. I do not find the modelling to provide in itself an evidential source of proof. The evidence included expert opinion, on matters of engineering (geotechnical and construction), geology, hydrology and survey. Recapitulation of this mass of material will not progress the effective determination of the interlocutory issues presented by the separate questions.

69 In answering the questions posed about unnatural water source I am presented with the opposing views of highly qualified experts. I am not qualified to speak with authority on matters of geology, geotechnical engineering or associated technical specialties nor do I purport so to do. It is necessary however for me to make a decision on probability for the purpose of litigation and, I again emphasize, for that limited purpose. Whilst I should refer to some of the multitude of factors adverted to by the experts in formulating their respective opinions which were, in the course of hearing, the subject of intensive scrutiny by counsel, I consider that it would be pretentious of me to purport to assess the validity of the ingredients which gave rise to the conflicting opinions.

70 I limit myself to the forensic task.

71 I find that it is improbable that the construction of the Winterhaus wall was directly or indirectly the cause of a contribution of unnatural water to the groundwater table which precipitated the collapse of the slope. I include in that finding the proposition that the parking or movement of vehicles or equipment or the resurfacing operations of the Alpine Way disturbed the water main.

72 Subsequent to the landslide there was, of course, some removal of debris in connection with the rescue attempts. It is obvious that, at that point, observation for the purpose of identifying the cause of the slip was of secondary (if even that prominent) importance. I am conscious that as well as removal of debris there was activity such as the installation of temporary drainage. Whilst I have been provided with the detail about all of this, I do not perceive that it assists me in making my ultimate findings.

73 After the cessation of the rescue operations, there followed considerable activity in and around the site. In the course of time a host of bore holes were sunk and instruments such as piezometers and inclinometers installed. Mapping the site in this way would be accurate only in reflecting locations for the holes and the depths of piezometer readings and inclinations, as selected. It can fairly confidently be stated that the totality of investigations of this nature do not support an unequivocal conclusion. Much time was occupied at the hearing exploring the reasons why the individual experts included or excluded some of the information derived from these sources in formulating their opinions.

74 My finding above stated is principally based upon the absence of any significant groundwater contribution via the Winterhaus wall being observed after the landslide. In short, if deficiencies relevant to the wall caused unnatural groundwater flow before the landslide, then it must be expected that things would be no different after the landslide and such a groundwater flow would have to go somewhere. The intensity of investigation was such that, if there were such diverted flow, it would inevitably have been detected. A tiny emanation could not be germane.

75 After the landslide, the scarp surface was saturated but it dried out relatively quickly. It did not wet again, yet the wall remained in place, its drainage system operating as before and indeed it was not interfered with until deconstruction nearly a year and a half later. Of course, during that period major works were undertaken. Not only was the road rebuilt but considerable excavation was undertaken. During those works, I note the installation of horizontal drains. Their function did not demonstrate that the wall was deficient in its drainage system. Had it been the source of contributing unnatural groundwater, this unnatural moisture had to appear somewhere, yet none of any significance was detected.

76 I do not overlook the debate, in particular, between Dr Redman and Dr De Ambrosis as to the extent of the rise needed in the groundwater table to trigger the landslide. Nor do I overlook the evidence about the sufficiency of the seal of the drainage under the Winterhaus Wall and the infiltration tests conducted in connection with it. I am not satisfied that any of this material establishes a probability of water diverted by the wall construction causing a sufficient rise in the groundwater table to be relevant.

77 The contesting parties have presented several volumes of written submissions. Contained within them are detailed references to immense number of individual facets of the evidence. Except that they represent matters of contest, it is difficult at times to determine precisely what submission is being made in connection with my task of answering the separate questions. On numerous occasions during the hearing I attempted to caution against the issues of litigation being submerged under the technical detail to which the parties had access. I need hardly comment that each of the opposing conclusions has been presented in the context of sophisticated technical analysis by expects of selected data and, as I have said, I am not in the position of being some kind of superior determining expert. Little would be gained by my attempting to adopt such a role. If I were so to do, it would not do other than provide a fertile field for continued disputation. Thus I will confine myself to the reason that I prefer the position that the construction of the Winterhaus Wall was not a relevant contributor, namely, that if it was diverting unnatural groundwater pre-landslide so as to raise the groundwater table then, post-landslide and in the absence of any variation to its structure and operation, it should have continued to divert unnatural groundwater somewhere yet despite the microscopic examination of this relatively small area of land there was no relevant detection of a sufficiency of such.

78 The next issue is whether the water main, the only suggested alternative, was the relevant source of unnatural water. It needs to be remembered that a significant part of the water main was never recovered. This was essentially that part which traversed the down slope to the west of Carinya from just under the Alpine Way to the Bimbadeen Pump apparatus. The probability is that the remnants were disposed of during the emergency operations clearing the landslide overburden from the buried lodges.

79 Although no detailed plan of the relevant pipeline ring is available, the post-landslide excavation revealed an adequate amount of information. I have already mentioned some matters concerning the route of the line and its embedment beneath the verge on the north side of the Alpine Way. There is evidence, which I accept, that as situated the pipe would in the course of years have been subjected to force by soil creep. That the general area was affected by creep can be deduced from observations of the leanings of trees and the conclusions of experts. The question is, however, whether the pipe had fractured and/or leaked at fracture points or at joints (by pull apart) prior to the landslide and thereby contributed unnatural water addition to the groundwater table so as to provoke the inculpatory rise in level.

80 The main protagonist (in terms of expertise) of the theory that water escaping from the main was the cause (in the sense I have earlier mentioned) of the landslide was Dr De Ambrosis. I do not consider that every one of his expressed reasons are supportive of his conclusion. As is not infrequently the case, his initial opinion was based upon the facts he was asked to assume, which facts were not precisely the eventual evidence especially following cross examination. However, witnesses do not usually restrict themselves to the exact content of statements. Allowing for such, his opinion is nevertheless persuasive.

81 I accept his evidence that, upon exhumation of the pipe, he observed pipe pull out (at Joint 1) so that the pipe was clear of the V-ring. Undoubtedly whenever this was the situation, water would leak but I am unable to conclude that this was the situation prior to the landslide for a sufficient time to be relevantly causative. I also accept that in due course he observed a groove, a flat spot and black markings on the spigot of this part of the pipe. There was considerable debate about the interpretation of these observations. I am unpersuaded that they evidence, either individually or in combination, a leakage at Joint 1, which was causatively significant.

82 In this context I should also refer to the evidence of Mr O’Reilly concerning his observation when he moved a post in the Schuss car park a short time before the landslide. His evidence needs to be gauged with evidence of rainfall events at about the time. I find Mr O’Reilly’s evidence suggestive that the main may have been leaking at the time but I am unable to determine from it that it probably was.

83 Dr De Ambrosis also derives support for his opinion from his observation of “pipe” holes behind one of the rocks which was in position after the landslide. Again, whilst I accept his observation, I do not find the conclusion which he derived determinative.

84 Accepting, however, as the parties have presented their cases that there was only two possible sources of the unnatural water contribution, I find that the water main was the more probable source. I recognize that I do not base this upon particular positive evidence but I reject the submission that, in the circumstances, that finding is to be categorized as mere speculation. The circumstance is that parties to the litigation agree that there are only two possible sources of the water and, as I am satisfied of the contrary of the theory that the building of the Winterhaus Wall should be inculpated, it remains the only available deduction that the source must have been the water main.

85 The facts do not undermine that conclusion. The water main was an obvious source of sufficient water to contribute to a rise in the natural ground water table. Its position was appropriately relevant to ground water seepage paths. In this regard, the identification and mapping of the alteration zone by Mr Kotze is a significant matter of background when contrasting possible sources. I do not accept that, to inculpate the water main in a relevant sense, there would have to have been a loss of water from the system such as would be reflected in major depletion from the holding tanks. Any loss is likely to have been gradual and, given the information available, probably came from somewhere in that part of the line that was lost in the landslide.

86 That finding of probability is fortified by the existence of and the calculations of creep in the area and the inevitable force that this would have exerted on the pipe over something in the order of thirteen years. For this time the brittle pipe was in moving ground as demonstrated by the observations of Joint 1 post-landslide, if given sufficient force the seal system was capable of pulling apart.

87 I do not accept the contention that the “approval” of the construction of the water main by NPWS imposed a liability upon it for any deficiency in construction in the sense of making provision for the long term effects of creep. It suffices for present purposes to record my conclusion that it was not in the circumstances, the supervisor of KT1 and entitled to expect that KT1 would competently attend to any necessary detailed aspects of engineering construction. NPWS approval was to installation and general conditions as to so doing.

88 To return to the issue, of the two “candidates”, I find that the water main was the probable source of unnatural water contribution.

89 An alternative proposition that it might be found that both the construction of the wall and emanation from the water main contributed to the ground water table rise was advanced. As I have indicated, so far as inculpation of the wall is concerned, my view is that the improbability of its contribution is established on the trial evidence and my finding is not simply that inculpation is “not proven”. In that circumstance, the alternative proposed should be rejected.

90 I turn to factors relative to the condition of the slope. Setting to one side distinction between different State interest entities, significant admissions made for the purposes of the litigation should be noted. The fill embankment above Carinya was subject to some movement through creep and was poorly compacted. Control of drainage was critical to stability of the Alpine Way. Introduction of water into the fill could adversely affect any areas of marginal stability and, if in sufficient quantities, failure of the slope in that area could occur. I interpolate my finding that the slope above Carinya was of such marginal stability. The Alpine Way was less likely to collapse if the fill was removed and suitably replaced.

91 So far as it may become relevant the National Parks and Wildlife Service (the Director General) had assumed care, control and management of the Alpine Way from 1975 and its officers carried out such investigations as there were with reference to stability and drainage. Such officers also determined priorities and carried out maintenance on the road from time to time.

92 In 1980, in connection with a proposed subdivision of the western segment of the village KT1 obtained a report from Coffey & Partners “Consulting Engineers in the Geotechnical Sciences.” The State interests admit knowledge of the content of this report. Although, of course, not site specific to the eventual landslide, it presented much cautionary information applicable to the area in which it had been chosen to locate the Thredbo Village.

93 Some passages from the report can be cited:

“Under the most adverse ground water condition, where the piezometer level reaches the surface of the topsoil layer, the factor of safety at all cross sections along the Alpine Way approaches unity, and failure of the road embankment can be predicted.
……………..
On the basis of stability analyses, the control of ground water is critical in ensuring the long term stability of the Alpine Way.
……………..
Satisfactory stability exists only for ground water levels located below the surface of the extremely weathered rock, a condition which was generally not encountered at the time of the field investigation.
……………….
The existing stability of the Alpine Way road embankments and the hill slope below the road embankment is not considered to be satisfactory under the present ground water conditions, and could become marginal under a severe ground water condition with piezometer levels at the natural ground surface. Hence, remedial measures should be adopted to improve this stability.”

94 It is convenient to mention at this point the considerable attention directed by counsel to the development (between 1991 and 1995) of a slope risk rating system by the RTA. The method envisaged by the system was to assign a risk rating (based on visual inspection) to slopes located along the RTA network. There is no evidence of the total length of the RTA road network but it must be very substantial and the particular slope below the road and above Carinya would be a miniscule fraction of the whole. Much effort was devoted (by lawyers) to (ex post facto) application of the system to the Carinya slope. The publication of the system was an ongoing work presented in “editions”. I do not consider that reasonableness required that specific risk rating be undertaken in respect of the particular slope. There is no evidence suggesting that the system, apparently developed for its own purposes, was communicated by the RTA to the NPWS prior to the landslide but, in any event, the system was as a matter of practicality incapable of being instantly adopted to every slope above and below every stretch of road in New South Wales. I do not consider the exploration of this topic relevant.

95 Relevant however, were the investigations of a Mr Warren-Gash. Documentation describes him as “Scientific Officer, Roads and Traffic Authority”. A series of reports from him are endorsed “requested by National Parks and Wildlife Service”. The admissions on behalf of the State interests include knowledge of the contents of reports prepared by him between 1991 and 1996. There is, in addition, a report of some inclinometer readings dated 4 August 1997. There is no reference therein to the landslide which had occurred a few days prior to that date. The readings may have been taken pre-landslide and the text is limited to:

“Attached are the inclinometer sheets. There has been no significant movement in either of them.”

96 Mr Warrant-Gash was not called to give evidence. I would have expected the State interests to call him. The absence of testimony from him was not satisfactorily explained. I conclude that his evidence, if called, would not assist the case being presented by the State interests.

97 His reports need to be read in full, in sequence and in context but the essence of the matters which he conveyed can be seen in some extracts therefrom.

98 His first report concerns a site visit to the Alpine Way near Thredbo on 5 August 1991. I extract the following therefrom:

“This site visit was to make a preliminary visual assessment of areas of potential instability. The report also makes recommendations for further work to more fully investigate some areas where failure, if it were to occur, could cause property damage. It is noted here that nothing of immediate concern was seen in the Thredbo area and only one side that will require attention this financial year was seen on the road to the northeast of Thredbo. Even here, the road is not immediately endangered.
……………..
In several of the cuttings the road pavement showed arcuate cracking. It is considered that this cracking has been caused by settlement of the fill, particularly as it is understood that felled trees were incorporated in the fills and these are rotting and support from them is being lost. Old logs were seen protruding from and supporting the fills in a number of places. Where the cracking occurs the ground is very steep. The slopes were not measured but area estimated to be greater than 40 degrees in places. There is therefore the possibility of creep within the fill materials as well as settlement.
……………..
It is suggested that inclinometer tubing be installed in the outer edge of the road above the Winterhaus Guest Lodge and one or two other key buildings.”

99 In February 1992 a report conveyed “an inventory of landslides and potential landslides along the Alpine Way from the entrance gate to Dead Horse Gap.” His various comments confirm the already expressed view of the nature of the area as prone to slippage. The village is in the approximate area between road points 13.2 kilometres and 14.4 kilometres which Mr Warren-Gash measures from the entrance gate.

100 At a point 13.7 kilometres to the north of Culvert 135 he observed:

“There are longitudinal cracks in the eastern bound lane of the pavement.”

101 It was noted that an inclinometer was installed near Culvert 137. The locations of the culverts are shown on the many copies of plans available in the evidence.

102 His report included:

“In general terms there are a number of factors that are contributing to the lack of stability of the road. These are: the steepness of the natural slopes, the steepness of the fills, the inclusion of trees in the fills and the generally high water table.
……………..
The fills under the road have been constructed from the soils and weathered rock cut directly from the hillside. They have been constructed at angles up to 15 degrees more than the natural maximum for the soil slopes.
……………..
Prevention of rise in water tables and the active reduction of the water table can be achieved by drainage and the maintenance of the existing drainage.
……………..
Continuing inspection and maintenance of the culverts is essential to protect the deepest and most vulnerable parts of the fills.”

103 At this point Mr Warren-Gash’s conclusions included:

“Measures that need to be taken to preserve the road as a safe access to Thredbo fall into four categories. These are: support and repair of slips, drainage, protection from falling rocks and monitoring.
……………..
Stand pipe piezometers installed in the shoulder of the uphill side of the pavement will give an indication of the present depth to the water table.”

104 It is admitted that NPWS did not install any piezometers.

105 The continuing reports from Mr Warren-Gash are, in my assessment, describable as complacent although he maintains his presentation of cautionary advice. In 1994 he made reference to points 13.7 kilometres to 13.9 kilometres as follows:

“The depressions may have increased slightly, although this is not certain. The cracking in the pavement in this area seems to have become more prominent. It should be monitored carefully.
……………….
Drainage continues to be critical to the stability of the road.”

106 The final report by Mr Warren-Gash prior to the landslide was dated 13 August 1996. Its penultimate paragraph reads:

“Due to the steep slopes in the area, the high water table and the apparent lack in preparing the ground at the time of the original construction of the road, slope failures can be expected. These failures can be controlled or considerably reduced by lowering the water table in the road embankment. This can be easily achieved by installing deep lateral drains along the uphill side of the road which themselves drain in to the culvert inlet pits. It is recommended that this sort of drainage be installed in all cross cut areas between the Park gate and Thredbo.”

107 Mr Warren-Gash was not, of course, the only source of knowledge which ought be imputed to the defendants. Not only was there a history of land slide (geological examination has confirmed such occurrences stretching back through millennia) but there were specific slides in the several decades before the fatal landslip. The evidence reveals slides which directed affected the road which required temporary closure.

108 Whilst I am of opinion that some of the possible remedial engineering undertakings suggested on behalf of the plaintiffs are extravagant and beyond the bounds of reasonableness in the circumstances of an access road of the status of the Alpine Way, I do not consider that the defendants should have been content simply to respond to imminent difficulty revealed by such things as cracking on the surface and obvious subsidence. In current jargon, the very least requirement was some pro activity. The evidence reveals none of any significance. As Mr Warren-Gash advised in the passage from his report of 13 August 1996 above quoted, there were ways of “easily” achieving control or reduction of the risk of slope failure.

109 I am conscious that Dr De Ambrosis has opined that, absent an unnatural source of water, the embankment would have continued with the same level of “past performance”. However it was the risk of collapse, however caused, that the defendants addressed in only a cursory and inadequate way.

110 The foregoing encapsulates my finding relevant to the identified issues, namely, was the rise in the ground water table caused by unnatural water addition sourced from (a) the water main, or (b) as a consequence of the construction of the Winterhaus Wall, or (c) both of the above, and was the response to risks of which the defendants knew or ought to have known, were posed by the slope below the Alpine Way of which NPWS have the care control and management reasonable to the circumstances.

111 As I have said, the foregoing discloses my findings. It obviously does not canvass the immense mass of technical evidence which the parties chose to put before the Court. I repeat that I would not claim to be qualified to determine the validity of the opinions of the experts. In so far as it is of consequence for me to make such an observation, the premises advanced by each of them were evidently arguable. Despite the apparent approach adopted by the parties, my task is to answer the questions posed in accordance with findings as to probability and I will limit myself to so doing.

112 I have considered whether, in the interests of what might be thought to be some form of completeness, I should record my views about the many collateral skirmishes which extended the hearing so as to produce thousands of pages of transcript together with the mammoth amount of documentary evidence. I propose not to do so. The answering of the preliminary questions is an interlocutory exercise originally undertaken with the express aim of advancing towards what has since been articulated as “just, quick and cheap resolution of the real issues” (SCR Pt 1 r 3). In the circumstances, and despite the posture insisted upon by the contesting parties, it remains inappropriate to conduct an engineering investigation of the slope, as reflected in the written submissions in particular.

113 Insofar as it may be possible to pursue the stated aim in relation to the one remaining unresolved claim, I turn to the specific questions.

114 Although the separate questions have already been set out it will provide for more convenient reference if I repeat them.

Q1. Was the landslide caused solely, or materially contributed to, by water which came from one or more fractures of leaking joints in the pipeline?

A1. Yes, it was materially contributed to by water from such sources.
Q2. Was the landslide caused solely, or materially contributed to, by water which came from additional flows, if any, resulting from the construction of the Winterhaus Corner retaining wall?

A2. No.
Q3. Was the landslide caused, or materially contributed to, by both of the causes set out in paragraphs 1 & 2 above?

A3. No.
Q4. Was the landslide caused, or materially contributed to, by part of the slope above and to the south west of Carinya being poorly compacted, overly steep, marginally stable or vulnerable to a small elevation in either the groundwater table or groundwater pressure? If so, which part of the slope and which of those causes?

A4. Yes, the landslide was materially contributed to by the condition of the slope as to each of the factors described. It was vulnerable to elevation in the ground water table. I am unable to determine with exactitude the extent of necessary elevation. I note the conflicting views on this aspect, particularly between Dr Redman and Dr De Ambrosis. I consider the necessary rise would not be accurately categorized as “small”. Dr Redman commented that rise could follow a major rainfall event. There had been none in the time proximate to the landslide but no doubt there had been such in the past and, although the condition of the slope was similar (allowing that it probably deteriorated over time as, for example, the organic content decayed) the slope had not collapsed. A rise in the order of that postulated by Dr De Ambrosis would have been more likely. It is common ground (in the sense that all experts called agreed) that there had been some introduction of unnatural water to the ground water table in the slope.
The enquiry as to which part of the slope had the stated qualities (or deficiencies) does not invite a relevant answer. The event involved two major earth movements, first the slip from near the Schuss car park which moved northeast and impacted Carinya near its east aspect and, second, a slip triggered by the first which moved directly downhill destroying Carinya on the west and continuing to strike Bimbadeen. Whether some parts of the slope did or did not have the deficiencies stated is of no consequence, if the existence of any permitted the collapse of the whole.
Q5. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of creep in the fill?

A5. Yes. I am not satisfied that the design, construction and maintenance of the water main was unreasonable save in those aspects which it did not cater for the long term effects of movement caused by soil creep.
Q6. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of the direct or indirect impact of construction activity associated with the construction of the retaining wall?

A6. No.
Q7. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline, was that leakage solely the result of the direct or indirect impact of construction activity associated with the resurfacing of the Alpine Way?

A7. No.
Q8. If the landslide was caused, or materially contributed to, by leakage from one or more fractures or leaking joints in the pipeline was that leakage caused by more than one of the causes set out in paragraphs 5, 6 & 7 above? If so, which of those causes?

A8. No. See answer to question 5.
Q9. If the landslide was caused, or materially contributed to, by water which leaked from one or more fractures or leaking joints in the pipeline, was the pipeline inappropriately located, designed, constructed, approved, operated and/or maintained?

A9. To the extent specified in the answer to question 5. Approval was not germane to causation.
Q10. If the landslide was caused, or materially contributed to, by water which came from additional flows resulting from the construction of the Winterhaus corner retaining wall, was the Winterhaus Corner retaining wall inappropriately designed, approved and/or constructed?

A10. See the answer to question 2.
Q11. Which acts or omissions, if any, were responsible for the operative cause or causes of the landslide set out in paragraphs 1, 2, 3 & 4 above, and to what extent?

A11. The “operative causes” are identified in the answers above given. Those responsible for the installation and maintenance of the water main ought to have been aware of the risk of failure and consequent leakage as a result of soil creep. No adequate steps were taken to accommodate and avoid this risk. Avoidance of that risk was practicable. Those responsible for the care control and management of the Alpine Way ought to have been aware of the condition of the slope supporting the road near Carinya but did nothing to stabilize it. Such stabilization was practicable. I have taken into account the submission on behalf of the State interests concerning the subtleties of the influence of hindsight. Whilst it was no doubt prudent to take steps such as having Mr Warrant-Gash seek to inventory potential slip sites along the Alpine Way from the Park entrance gate to Dead Horse Gap, there was self evidently a need to give particular focus to those areas (including specifically the slope above Carinya) which might threaten the populated village.
Q12. Was the Thredbo landslide caused by:
(a) the marginal stability of the slope above Carinya;
(b) the existence and state of the Alpine Way;
(c) the omission to improve the stability of the slope above Carinya (including the Alpine Way) in accordance with acceptable standards and accepted practice, before the landslide;
(d) infiltration from the Winterhaus retaining wall drainage trench;
(e) leakage from the water main; or
(f) a combination of (a) (b) (c) (d) and/or (e) and if so, the extent of each cause.
A12, (a) Yes.
(b) Yes.
(c) Yes.
(d) No.
(e) Yes.
(f) Each of the principal factors, the unameliorated instability of the slope and the introduction of water contributing to raising the ground water table was a sine qua non of the landslide. I would apportion the extent of contribution between each of those equally.
Q13. If the Thredbo landslide was caused by leakage from the water main or such leakage contributed to the landslide, was the cause of such leakage:
(a) construction activity associated with the construction of the Winterhaus retaining wall;
(b) construction activity associated with the resurfacing of the Alpine Way following construction of the Winterhaus retaining wall;
(c) soil creep; or
(d) a combination of (a) (b) and/or (c), and if so, the extent of each cause.
A13. (a) No.
(b) No.
(c) Yes.
(d) No.
Q14. Was the slope above Carinya, and in particular the Alpine Way, designed, constructed, maintained and monitored in accordance with acceptable standards and accepted practice.
A14. As previously stated, the slope was not initially designed but came into existence as the result of the driving of an access track for the purposes of the Snowy Mountains Hydroelectric Scheme and the village was later imposed into the area. However, once the village was established within the National Park it became the duty of NPWS (or the RTA if acting as its agent) to maintain and monitor it. As mentioned in answer 12(c) above it did not adequately do so. I note that neither party has suggested that it would be relevant to consider any past responsibility which may have been undertaken by the Shire Council.
Q15. If the water main leaked, in a way that caused the landslide, did it do so by reason of the fact that it was located, designed, approved, constructed and/or maintained following construction, other than in accordance with accepted standards and accepted practice.
A15. See the answer to question 5.
Q16. If there was infiltration from the Winterhaus retaining wall drainage trench, in a way that caused the landslide, did it do so by reason of the fact that the Winterhaus retaining wall was designed, approved, constructed and/or monitored following construction, other than in accordance with acceptable standards and accepted practice.
A16. See the answer to question 2.
Q17. Was the geotechnical advice from the RTA to the NPWS from August 1991 until the landslide, advice that a reasonably competent geotechnical engineer would have provided during that period in relation to the stability of the slope above Carinya? If not, what advice would a reasonably competent geotechnical engineer have provided to NPWS, in relation to the stability of the slope above Carinya, during that period?
A17. The question treats geotechnical advice compendiously. Among other things the evidence includes various memoranda, the reports of Mr Warren-Gash to which I have made reference above and indirectly, advice obtained in a report commissioned by NPWS (May 1991) from Sinclair Knight, consulting engineers concerning funds and upgrading the Alpine Way. It might be noted that the report included:
“……Some land slippage is evident especially adjacent to the village. A landslip would not only cause severe damage to the road but may also damage property and subsequently endanger human life. Remedial action is recommended to reduce this possibility.”

The significant matter is not the quality of the advice given from time to tie but the failure to focus upon the area of danger to the village. There was ample paper generated and opinion expressed concerning potential landslip but, in effect, nothing concrete was done. There was no geotechnical advice given in relation to the specific slope above Carinya. In that absence it is academic to pursue what might have been said.

115 Liberty to the parties to apply, if necessary, for directions as to future hearing.

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Last Modified: 07/16/2007