Roberts v Rodier

LEGISLATION CITED : Conveyancing Act 1919 Uniform Civil Procedure Rules 2005

ASIC v Edwards [2004] NSWSC 1044; (2004) 51 ACSR 320 Bone v Seale [1975] 1 WLR 797 Butler and others v The Egg and Egg Pulp Marketing Board (1966) 114 CLR 185 Bresatz v Przibilla (1962) 108 CLR 541 The Commonwealth v Amann Aviation Pty Ltd (1991) 174 CLR 64 Dillingham Constructions Pty Ltd v Steel Mains Pty Ltd (1975) 132 CLR 323 Dominion Mosaics and Tile Co Ltd and another v Trafalgar Trucking Company Ltd and another [1990] 2 All ER 246 Fennell v Robson Excavations Pty Ltd [1977] 2 NSWLR 486 Griffiths v Commonwealth of Australia (1983) 72 FLR 260 Haines v Bendall (1991) 172 CLR 60 Harbutt's 'Plasticine' Ltd v Wayne Tank and Pump Co Ltd [1970] 1 QB 447 Hunter v Canary Wharf Ltd [1997] AC 655 Hunter Area Health Service v Marchlewski (2000) 51 NSWLR 268 Hyder Consulting (Australia) Pty Ltd v Wilh Wilhelmsen Agency P/L & Anor [2001] NSWCA 313 J & B Caldwell Ltd v Logan House Retirement Home Ltd [1999] 2 NZLR 99 Jobling v Associated Dairies Ltd [1982] AC 794 Johnson v Perez (1988 - 1989) 166 CLR 351 Kralj v McGrath [1986] 1 All ER 54 Leschke v Jeffs & Faulkner [1955] QWN 67 CASES CITED : Livingstone v The Rawyards Coal Co (1880) 5 AC 25 Lumley General Insurance Ltd v Vintix Pty Ltd (1991) 24 NSWLR 652 Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 Malec v JC Hutton Pty Ltd (1990) 169 CLR 638 McColl v Dionisatos [2002] NSWSC 276; (2002) Aust Torts Reports 81-652 Monroe Schneider Associates Inc v No 1 Raberem Pty Ltd (1991) 33 FCR 1 Norris v Blake (by his tutor Porter) (No 2) (1997) 41 NSWLR 49 Oldham v Lawson (No 1) [1976] VR 654 Optus Networks Pty Ltd v Leighton Contractors Pty Ltd & Ors [2002] NSWSC 327 Pantalone v Alaouie (1989) 18 NSWLR 119 Performance Cars Ltd v Abraham [1962] 1 QB 33 Purkess v Crittenden (1965) 114 CLR 164 Ruthol Pty Ltd v Tricon (Australia) Pty Ltd [2005] NSWCA 443 Shellharbour Municipal Council v Rovili Pty Ltd (1989) 16 NSWLR 104 Simonious Vischer & Co v Holt & Thompson [1979] 2 NSWLR 322 Stockwell v Victoria [2001] VSC 497 TCN Pty Ltd v Anning (2002) 54 NSWLR 333 Thomson Australian Holdings Pty Ltd v Trade Practices Commission (1981) 148 CLR 150 Tyco Australia Pty Ltd v Optus Networks Pty Ltd and Ors [2004] NSWCA 333 Walsh v Ervin [1952] VLR 361 Willoughby Municipal Council v Halstead (1916) 22 CLR 352

Margaret Helen Roberts - Plaintiff PARTIES : Glen Rodier - First Defendant Helen Louise Rodier - Second Defendant Gosford City Council - Third Defendant

J Graves SC (20/3/06 & 24/3/06; L Byrne (20/3/06-24/3/06, 27/3/306 & 28/3/06) - Plaintiff COUNSEL : M Fraser - First and Second Defendant J Guihot (20/3/06-24/3/06) - Third Defendant

Central Coast Business Lawyers - Plaintiff SOLICITORS : Bowen & Gerathy - First and Second Defendant Moray & Agnew - Third Defendant

IN THE SUPREME COURT OF NEW SOUTH WALES EQUITY DIVISION EQUITY LIST

2711/03 MARGARET HELEN ROBERTS v GLEN RODIER & ORS JUDGMENT HIS HONOUR: Nature of the Case 1 Mrs Margaret Roberts owns land next door to land owned by Mr and Mrs Rodier. At all relevant times both blocks of land have had a risk of slippage. In the course of making an excavation to construct a driveway to his home, Mr Rodier excavated part of a road reserve which lay downhill from the plaintiff's land, and also removed a part of the plaintiff's land. After heavy rain some months later, that excavation triggered a slump of some of Mrs Roberts' land. The Rodiers carried out some remedial works, but Mrs Roberts was not convinced that those remedial works had been enough to remedy the damage which the excavation had caused. Mrs Roberts now sues Mr and Mrs Rodier, alleging trespass, nuisance and negligence. 2 Mr and Mrs Rodier admit that they have trespassed on the plaintiff's land on two occasions, and that the excavation was made negligently. The negligence consists in a breach of the duty of care arising under section 177 Conveyancing Act 1919. The defendants admit that, initially, the plaintiff suffered damage in consequence. The questions for decision concern :

(a) whether the plaintiff has established liability for nuisance;

(b) whether the plaintiff acted reasonably to mitigate the damage;

(c) whether the defendants have now rectified the damage they caused;

(d) if "no" to (c), what is the appropriate measure of damages; and

(e) if "no" to (c), ought the court accept certain undertakings proffered by the defendants to do work, in lieu of awarding damages. 3 The hearing was ordered to be a hearing on all issues between the parties save the monetary value of any deterioration in the plaintiff's land which might have been suffered in consequence of the conduct of the defendants. Layout and Topography of the Land 4 The plaintiff's land is known as 27 Table Top Road, North Avoca. The land approximately rectangular. It slopes downwards in, very approximately, the same direction as the long side of the rectangle. 5 The block has frontages to two different roads. At its upper end, the short side of the rectangle fronts onto Table Top Road. At its lower end, the short side of the rectangle fronts onto Surf Rider Avenue, North Avoca. Even though it is not strictly accurate, I will in this judgment adopt the same convention as has been adopted by various geotechnical experts in the case, and refer to the boundary of the plaintiff's land which is closest to Surf Rider Avenue as being its eastern boundary. 6 The usual way of obtaining access, either by vehicle or on foot, to the plaintiff's land is from Table Top Road. A driveway leads from Table Top Road to a carport on the plaintiff's land. 7 As one goes from Table Top Road in an easterly direction down the plaintiff's block, approximately the first 60% of it is developed with gardens, a house and deck, and a fairly level grassed area. A fence, of the kind placed around swimming pools, crosses the plaintiff's land at around this 60% mark. 8 As one continues down the slope in the plaintiff's land, past this fence, the character of the land changes radically. It becomes steeper, has some outcrops of rock in it, and numerous trees and other items of vegetation. There are no buildings in this part of the land. The vegetation looks like natural scrub, not a garden. 9 The defendants' land has a frontage only to Surf Rider Avenue. It adjoins the lower 40% or so of the plaintiff's northern boundary. A separate land title, owned by someone else, adjoins the upper 60% or so of the plaintiff's northern boundary. 10 The plaintiff's eastern boundary is 20.42m long. Surf Rider Avenue has a bitumen surface, but no kerbing and guttering on the side where the land of plaintiff and the defendants lies. A road reserve lies between the eastern boundary of the plaintiff's land and the edge of the bitumen in Surf Rider Avenue. That road reserve is of variable width. Scaling from surveys shows that, depending where along the plaintiff's eastern boundary one measures it, the road reserve is between 5m and 6m wide. A road reserve of similar width lies between the defendants' eastern boundary and the bitumen in Surf Rider Avenue. The land in that road reserve slopes downwards, with the slope running from the eastern boundaries of the plaintiff and the defendants to Surf Rider Avenue. 11 When Surf Rider Avenue was first constructed, there were extensive cut embankments along its uphill side, and fill embankments along its downhill side. The cut embankment near the eastern end of the plaintiff and the defendants' land slipped in 1975. After a further slip in 1981, the Council constructed a crib wall, made of what appear to be concrete beams intersecting to form hollow rectangles. That crib wall extended along, very roughly, the bitumen edge adjacent to the southern half of the defendants' land, and the northern one-third of the plaintiff's land. 12 Mr Brink, a geotechnical engineer engaged by the defendants, described the defendants' land as follows in May 2002: "A fill embankment rises from roadlevel to the eastern boundary of the land; it is up to about four metres high, but its southern half is obscured by a concrete criblog retaining wall. Above the retaining wall the surface is uneven and rises westerly at an average gradient of about 25 º , with a near-vertical arcuate embankment forming its upper limit. The natural bouldery surface rises westerly at 20º to 25º to terminate at a concrete block retaining wall along the western boundary. The wall is up to 1.5m high and retains a filled garden terrace that forms the backyard of the adjacent house uphill. GEOLOGICAL and GEOTECHNICAL ASPECTS: The extensive road cut embankments below the land and elsewhere along Surfrider Avenue expose the entire soil profile and rock sequence that underlie the land. Near-vertical rock faces consist of yellow and orange mottled quartz lithic sandstone that is weathered to varying degrees. The strata represent the upper section of the Triassic Terrigal Formation, which is a widespread, flatlying sequence of interbedded lithic sandstones, siltstones and shales. Where such strata are exposed at or near the surface they tend to weather to form a surficial layer of more or less sandy residual clays and a layer of such residual clay is exposed above the rock faces and in the arcuate embankments above the retaining wall. The residual clay is about 1.5m thick and includes a gravely slopewash and soil layer that also contains some large sandstone boulders. It is apparent that the road cut embankment has suffered instability in the past and that the existing retaining wall was constructed to protect the worst affected part. The retaining wall was not constructed to the full height of the embankment, nor was the upper part laid back at a smooth batter. Consequently, the slope instability has continued to progress uphill, with a near-vertical arcuate scarp marking its current position. Active erosion of the scarp was noted above the southern end of the retaining wall and beyond."

I infer that the geological character of the plaintiff's land is similar. 13 There was existing slope instability on the plaintiff's land prior to the defendants commencing to excavate their driveway. After the landslip in 1975 there were further slips. One occurred in October 1981 on the plaintiff's land, connected with the installation of a sewer at a location, towards the south of the plaintiff's land, which all experts in this case agree is not causally connected with the land slippage which gives rise to this litigation. As well, there was another slippage partly on the plaintiff's land and partly on the road reserve adjacent to it in April 1988. The 1981 and 1988 slippages had both occurred following a period of heavy rain. 14 In the lower portion of the plaintiff's land, east of the fence which crosses the land, there are still signs of the earlier landslips. There are some quite steep scarps in that portion of the area, some nearly vertical, where the earlier landslides had occurred. Those earlier landslides took the form of slip circle or wedge landslide failure. As well, the plaintiff's land shows some sign of soil creep, evidenced by tension cracking in the soil profile and leaning trees, between the top of those scarps and the residence. This soil creep is a long-term phenomenon, not the same as the slip circle/wedge landslide failure which had resulted in the scarps. 15 The plaintiff's land has 1.5m to 2m of soil above the bedrock. Closest to the bedrock is a layer of residual soil, ie soil formed by the weathering at that place of the bedrock. Above that is a layer of colluvium, ie soil which has moved from higher up the slope to be in its present position. The soil creep on the plaintiff's land is a type of soil creep which is typical on steep slopes. It is common in the North Avoca area. 16 The location of the scarps on the plaintiff's land had been recorded by geotechnical engineers or surveyors at various times. The location of the scarp which is furthest from the plaintiff's eastern boundary has been established by a survey of C R Hutchison & Co Pty Ltd in December 2005. It runs very roughly parallel to the plaintiff's eastern boundary, though curved somewhat, so that towards the centre of the block the scarp is further from the boundary than at the northern boundary and at the spot, towards the southern boundary of the plaintiff's land, which is a prolongation westwards of the end of a wall, of which more emerges later (para [49] below), which I call the Driveway Retaining Wall. That scarp lies, very approximately, 7m to 8m back from the Driveway Retaining Wall. That scarp is sometimes referred to in the evidence as the "back scarp", and is sometimes referred to as the "Hutchison Line". 17 The plaintiff's land was purchased by the plaintiff and her then husband in 1984. It came to be transferred into the plaintiff's name in about 1987. The plaintiff has been residing there permanently from about 1990 or 1991. She was aware of the 1988 slippage having happened on her land (though, by the time of the trial, she mistakenly remembered it as having happened after 1988). She was aware that her husband had tried, through a lawyer, to get some compensation from the Council concerning that slippage. Both the plaintiff, and the defendants, were aware that their land was sensitive to slip. The Access Steps 18 A track, traversable only on foot, led from the plaintiff's backyard to Surf Rider Avenue. Its precise location within the plaintiff's land was not established by the evidence. A set of steps, at least six in number, and possibly as many as eight, led down to a position in the road reserve immediately adjacent to the bitumen. Those steps were fairly crude, consisting of risers comprising planks of wood, each of which retained the earthen tread of the step. It is a type of step familiar to Australian bushwalkers. 19 The exact location of those steps has never been established by survey. There was dispute in the evidence about their precise location. A photograph taken on 8 October 2002 shows the steps, and also shows a surveyors peg with fluorescent pink tape on it, of the kind used by a surveyor, Mr Hunt, to mark the plaintiff's boundary. That photograph has been reproduced, and appears in more than one place in the evidence, but the clearest version of it is Exhibit M. The steps lay a little to the south of the end of the crib wall which supported the embankment of the road reserve in the northern part of the plaintiff's land. The camera which took that photograph was not pointing in a direction perpendicular to the edge of the bitumen - rather, it was pointing somewhat to the north of west. Recognising that, it is apparent from the photograph that the steps were not constructed so that a person descending them would be travelling perpendicular to the bitumen edge - rather, they were constructed at an angle to the bitumen edge, so that a person going down them would, to some extent, be traversing the slope, as well as descending it. The road reserve at that point is nearly 6m wide. Even if there were eight risers in the steps (and in the photograph I can only see six), the treads of the steps would need to be most unusually long for the steps to extend into the plaintiff's land. The plaintiff, when cross-examined on the point, recalled nothing about the treads of the steps being unusually long. 20 While various witnesses made attempts to say where the boundary between the plaintiff's land and the road reserve lay, in relation to those steps, I am not satisfied that there was a firm foundation for any of those attempts. The plaintiff has not established that any part of the steps lay on her land. The October 2002 Excavation 21 Prior to October 2002 the defendants' land was vacant. The land of the plaintiff and the defendants lies within the local government area of the Gosford City Council. On 25 September 2002 the Council granted the defendants a development approval for construction of a house, and associated garage, on their land. The garage was to be located a few metres back from the eastern boundary of their land, and towards its northern end. The driveway giving access to the garage from Surf Rider Avenue left the bitumen, and rose up the road reserve in a roughly north-westerly direction. If one drew a line perpendicular from the point where the driveway met the bitumen in Surf Rider Avenue, back to the plaintiff's eastern boundary, that perpendicular would cross the plaintiff's boundary a few metres from the boundary between the land of the plaintiff and the defendants. (The approved plan in evidence does not enable any more precise finding than this to be made). The driveway in that approved plan runs well to the east of the plaintiff's boundary at all times, and crosses the defendants' eastern boundary at a point which is some metres north of the boundary between the plaintiff and the defendants' land. 22 Mr Rodier carries on a business as a concreter, in the course of which he regularly installs concrete slabs, and concrete driveways. In making a driveway, the first step is to "rough in" the driveway. This involves an excavator cutting an access in approximately the location of the proposed driveway, so as to enable trucks to remove and deliver materials from the site as well as to provide access to the site. Mr Rodier organised excavators and other necessary workmen and machinery to carry out the excavation for roughing-in the defendants' driveway, and supervised it himself. Under his supervision, the excavators excavated a location for the driveway which was different to the one the Council had approved. The path actually excavated left the bitumen in Surf Rider Avenue at a position further south than the Council had approved, and travelled quite close to the point at which the boundary between the plaintiff's land, the defendants' land, and the road reserve, met. Given the way that the land in the road reserve rose from Surf Rider Avenue, the path actually adopted would have resulted in a less steeply sloping driveway than there would have been if the driveway had been built in the approved position. It also meant, however, that the driveway extended considerably further to the south along the road reserve which lay outside the plaintiff's property. 23 In the course of roughing in the driveway the steps which gave access from the plaintiff's property to Surf Rider Avenue were demolished. 24 The defendants admit that, in the course of roughing-in the driveway, they cut away part of the plaintiff's land. Their defence contains an admission that, in October 2002, "… a small section in the south west corner of the Plaintiff's land was inadvertently cut away to the extent of about 6 inches horizontally and up to 2 feet vertically …"

In that admission, "south west" should clearly read "north east" . 25 A survey carried out by Bissett & Wright, on behalf of the defendants in December 2002 shows the toe of the excavation as passing inside the north-eastern corner of the plaintiff's land. The copy of the survey which was tendered in evidence is not to the original scale, so the extent of the incursion into the plaintiff's land which that survey shows can only be derived by calculation. That copy shows the boundary between the land of the plaintiff and of the defendants as being 21.91m long, represented by a line which is 98mm long. It represents the toe of the excavation as crossing the plaintiff's northern boundary at a point about 1mm from the plaintiff's north-eastern corner, and crossing the plaintiff's eastern boundary at a point about 7mm from the plaintiff's north-easternmost corner. If one scales those figures up, the survey would therefore be showing the toe of the excavation as crossing the plaintiff's northern boundary 22.35cm from the north-eastern corner, and crossing the plaintiff's easternmost boundary approximately 1.56m from the north-eastern corner of the plaintiff's land. When the purpose of the survey was to show the surface detail, and in particular the contours, I approach that derivation from it with some caution. Even so, it seems to me to provide the best evidence of the extent of the trespass insofar as it constituted excavation. 26 The plaintiff has a close friend, Mr Robert Bech, who is a Senior Environmental Health and Building Officer with a Sydney Council. He has provided assistance and advice to the plaintiff throughout the events which are the subject of this litigation. There are numerous photographs, taken by the plaintiff, Mr Bech, the defendants, geotechnical experts, and an officer of the local council, which show the land the subject of the dispute at various stages. Photographs taken in October 2002 show that the roughing-in of the driveway resulted in the creation of a low near-vertical wall of soil as the result of cutting away of land including, as is now known, a small part of the plaintiff's land immediately adjacent to her north-eastern corner. As well they show that there has been some scraping or scarring, of no great depth, of the bank which rises to the west of that near-vertical section. The scraped or scarred area shows on the photographs as being mottled in colour, with light brown, tan and off white components in the colouring. It is not the whole of the bank which has been scraped or scarred, but large parts of the area of the bank on which the scraping or scarring occurred have been scraped or scarred. 27 A comparison between a photograph showing that bank before the cut was made, and the bank after the cut was made shows that, before the cut was made the slope was covered with low vegetation like grasses and bracken. That low vegetation has been removed from the bank immediately above the cut, exposing the earth underneath. 28 The area of the plaintiff's land which was affected in this way cannot be precisely identified, but would extend of the order of 2 or 3m up the bank immediately adjacent to the plaintiff's northern boundary. While the area which has been affected in this fashion extends for substantially all of the length of the cut, because the cut is made at an angle the area of the bank on the plaintiff's land which has been cleared of vegetation and had its surface scraped or scoured would decrease in height, as one traversed along the plaintiff's eastern boundary from the north-eastern corner. 29 The plaintiff said, in the course of cross-examination, and with reference to what she could see from her balcony on 18 October 2002, "… with the earthmoving, that arm twists right around and I can see it very clearly from my top balcony and it moves around and it's scraping down with all the trees and shrubs and so forth coming with it …" 30 While I do not accept this evidence insofar as it refers to her seeing trees being brought down by the arm of the earthmover, I accept that this evidence explains the mechanism by which the scrapes or scars on the bank above the cut, which are visible in the photographs, were created. 31 The plaintiff has given affidavit evidence that on 26 October 2002 she and Mr Bech drove to her Surf Rider Avenue frontage. Her affidavit evidence was: "I could see that the excavator was making a cut across my land to construct what looked like a future driveway for the Rodiers land. I saw Mr Rodier standing on the opposite side of the road. I also observed that approximately 4 metres across the boundary of the property had been excavated to at least 10 metres in length." 32 In cross-examination, the plaintiff agreed that the "4 metres across" was the flat section of the driveway. The plaintiff did not impress me as a witness who had a particularly precise recollection of the events. As well, some suspicion was raised in cross-examination, which has not altogether been dispelled in my mind, that the plaintiff may not at the time have clearly understood the distinction between the land which she owned, and the road reserve. 33 Mr Bech gives evidence of having seen the excavation on 18 October 2002, when he observed "a large Caterpillar excavation and a number of male persons in and around the lower part of Margaret's property". While he said that "The excavator appeared to be coming on to Margaret's land and removing vegetation, soil and rocks from it," I am not persuaded that he had, at the time, a clear appreciation of precisely where the boundary between the plaintiff's land and the road reserve lay. 34 On 26 November 2002 Barry Hunt, surveyor, prepared a survey which identified the location of the gravel access drive which by then went from Surf Rider Avenue into the defendants' property, contour lines around the north-eastern corner of the plaintiff's property and also, on the western side of the gravel access road, lines identified as "bottom of bank", and "top of bank". On that survey, the "bottom of bank" forms the western boundary of the gravel access track. The "top of bank" runs roughly parallel to the "bottom of bank". By scaling from that plan, the "top of bank" is a little more than 2m up the plaintiff's northern boundary from its north-eastern corner. From that point, the "top of bank" gradually becomes closer to the plaintiff's eastern boundary, until it meets it around 9.5m from the north-eastern corner of the plaintiff's land. Taking into account that the area of a triangle is half its base times its height I would estimate the area of land which lies between the "top of bank" and the plaintiff's boundaries at somewhere between 10sqm and 12sqm. It is within that area that the bank which was on the plaintiff's land was cleared of vegetation, and in part scraped or scoured. 35 That area of 10sqm to 12sqm is one in a horizontal plane. The area of the face of the bank which was so affected would be larger. 36 At the time, the principal concern which the plaintiff expressed to anyone else was not that her own land had been cut or scraped, but that excavation within the road reserve might cause slippage problems on her land. By a letter dated 19 October 2002 (which the Council received on 21 October 2002), headed "unauthorised removal of Council land", the plaintiff complained that the driveway was not in accordance with approved plans, and said: "Excavation has commenced of a driveway within a Council easement for support without adequate shoring and sediment control erected at the base of my land. It is extremely urgent that this cut is retained as it may result in land slip of my land and loss of trees and vegetation." 37 Another letter which Mr Bech wrote to the Council, in the plaintiff's name, on 21 October 2002, complained that amongst other things, "… nor has council been advised of the excavation in council's road reserve." 38 These letters led to Mr Garry Male, a council officer, attending the property on 22 October 2002, and telling the defendants to stop work. He returned to the property on 29 October 2002, and found that further work had been done. I accept the evidence of Mr Male concerning these matters (on which he was not cross-examined) in preference to some contrary evidence from Mr Rodier about the dates on which Mr Male attended. 39 On 1 November 2002 Mr Prior, a solicitor consulted by the plaintiff, wrote to the defendants threatening legal proceedings, and requiring them to: "1. Not come onto our client's land except for the purposes of restoring and rectifying her property. 2. Attend to immediately restore our client's property to the same state and condition it was in prior to the commencement of your works. 3. Replant vegetation of a similar kind and nature to that which was previously growing on our client's property." 40 On 6 January 2003 the Council wrote to the defendants, enclosing a draft of an order requiring them to, in effect, reinstate the land they had interfered with in the plaintiff's land and the road reserve, build in accordance with the approved plans, and provide engineering evidence that their works were adequate. The Council invited representations as to why that order should not be made. 41 The defendants made such representations on 20 January 2003. After some consultation with the plaintiff, on 25 February 2003 the Council wrote to the defendants stating: "… that Council would not instigate legal proceedings for the works carried out to the driveway subject to strict compliance to the following: 1 The retaining wall and associated subsoil drainage is to be constructed wholly within your property and the road reserve. No part of the works are to encroach on No 27 Table Top Road. 2 Ground levels are to be reinstated to existing levels on No 27 Table Top Road, together with replanting of native species, similar to the vegetation that was in existence prior to the excavation commencing. 3 At completion of works a certificate being submitted to Council by a geotechnical engineer and a practising structural engineer. The certificate from the geotechnical engineer is to certify the stability of the site in connection to the excavation and reinstatement to ground level works. The structural engineer is to certify the structural engineering works carried out with the construction of the retaining works. 4. These required works are to be carried out within twenty-eight (28) days from the date here-of." 42 Mr Stephen Goodworth, another Council officer, gave evidence, on which he was not cross-examined, and which I accept, that: "(a) The Rodiers' unauthorised cut into the slope was a reality that had to be dealt with in the interests of both the Plaintiff and of public safety. The area was known to have landslip issues and there was a recent history of heavy rain. The cut was unsupported and needed to be retained as a matter of urgency. Any action that prevented this from occurring was not in the interests of the Plaintiff or of public safety. (b) Once the cut was made it was no longer feasible to consider options, such as that sought by the Plaintiff, involving reinstatement of the cut." 43 Not only was this Mr Goodworth's opinion - as well, he told the plaintiff about it. On 4 March 2003 Mr Goodworth spoke to the plaintiff at her home, and said words to the effect of: "The cut that has been made down there went further than we approved, and it is not in the approved location. But now that it is made, it is not possible to simply put the land back, and safely retain it. In order to retain the slope the existing cut will have to be retained." 44 The conditions upon which the Council had, on 25 February 2003, told the defendants it would not proceed with an order were not complied with within 28 days, or at all. On 31 March 2003 the defendants requested an extension of time from the Council. That request does not appear to have been replied to. Neither, however, did the Council issue any notice to the defendants. 45 On 8 May 2003 the plaintiff commenced these proceedings. She named Mr and Mrs Rodier, and the Council, as defendants. She sought orders restraining the Rodiers from doing any more work on the driveway, restraining them from using the driveway insofar as it traversed the plaintiff's land, a mandatory injunction for Mr Rodier to restore the land to its previous condition, and (from all defendants) damages, interest and costs. The Position of the Council in this Litigation 46 It is convenient to deal now with the position of the Council in this litigation. The plaintiff continued to seek damages, interest and costs from the Council in these proceedings, but in the course of the hearing the claim against the Council was settled. Thus, the Court received evidence not only from Council officers, but also from a geotechnical expert engaged by the Council. The settlement did not entitle the plaintiff to receive any money from the Council. The May 2003 Collapse 47 10 May 2003 was the start of a period of heavy rain. In the course of that rain, a part of the plaintiff's land and of the road reserve uphill from the excavation collapsed. The collapse occurred in several stages. Some slumping of the embankment occurred on 14 May 2003. On 15 May 2003 additional slumping of the embankment occurred, resulting in several cubic metres of clay slumping from below the soil profile that caps the upper edge of the embankment. A young tree collapsed from the bank above the driveway, falling across the driveway. By comparison between the length of the tree when horizontal as shown on a photograph taken on 17 May 2003, and the width of the access driveway shown on that same photograph, and which is known from Mr Hunt's November 2002 survey to be between 3 and 4m wide, I conclude the tree was over 6m tall. The tree's roots had helped to hold the bank together. It is not possible to reach a firm conclusion about whether that tree stood in the plaintiff's land or in the road reserve. 48 Mr Brink, a geotechnical engineer engaged by the defendants, attended the site on both 14 and 15 May 2003. He wrote a report (dated 14 May 2003, but obviously completed after that date as it also refers to an inspection on the afternoon of 15 May 2003) in which he expressed the view that: "The current failures have not yet affected the upper part, but unless the failures are arrested, they very likely will. It is recommended therefore to construct an engineer designed retaining wall to sufficient height to allow the slope above it to be laid back at batters not exceeding 1V:2H. Adequate drainage needs to be provided to accommodate seepage and run-off waters. The slope above the retaining wall needs to be covered with vegetation as soon as possible after completion."

If the slope above the retaining wall rose one unit vertically for every two units horizontally, it would be a slope of 26.5º. The Driveway Retaining Wall and the Second Trespass 49 On 20 May 2003 the defendants did work which involved removal of soil, rocks and vegetation which had slumped, and the commencement of construction of two sandstone block retaining walls. One of these walls ran along the westernmost edge of the driveway to the defendants' property, and was intended to provide support for the slope above that wall. It is that wall which I refer to as the "Driveway Retaining Wall". The other retaining wall was at the edge of the bitumen in Surf Rider Avenue, and provided additional support for the driveway both further south of, and above, the existing crib wall which ran just inside the road reserve. This other wall has not occasioned any controversy in these proceedings. 50 The defendants' solicitors wrote informing the plaintiff's solicitors on 20 May 2003 that the defendants were constructing a retaining wall to prevent any further slippage, and enclosed a copy of Mr Brink's report of 14 May 2003. 51 The plaintiff engaged the Coffey group, geotechnical engineers, to advise her. On 21 May 2003 Mr Fennell, a geotechnical engineer who worked for Coffey, visited the site, and saw the Driveway Retaining Wall under construction. His preliminary view, conveyed in a facsimile of 22 May 2003, was that construction of that retaining wall: "… will result in a risk of instability on the subject site of about the same level as that of the risk of instability of the slope prior to the excavation. It is considered that the risk of instability of the slope above the retaining wall is likely to involve slumping of the soil layer, which, due to the proposed geometry of the retaining wall and backfilling measures, will probably be battered at an angle that is steeper than its natural angle of repose of the clayey soils involved." 52 The defendants constructed the Driveway Retaining Wall so that no part of the wall itself is located on the plaintiff's land. 53 However, to enable the Driveway Retaining Wall to carry out its intended task, the defendants carried out some work and placed some material on the plaintiff's land. They entered on the plaintiff's land to remove loose soil rubble and other material that had fallen. The slope behind the Driveway Retaining Wall was backfilled with coarse gravel. A geofabric membrane was installed as a filter between the clayey natural soil exposed by the excavation and the gravel fill behind the wall. In the course of carrying out the work, black plastic sheeting was placed over the parts of the bank which had been cleared of vegetation. Backfilling of the Driveway Retaining Wall would inevitably have replaced the land of the plaintiff that was cut or scraped away in the October 2002 trespass. 54 Mr Brink advised the defendants, by a letter dated 22 May 2003 that"… the retaining wall needs to be completed within the shortest possible time during this period of dry weather conditions" otherwise, he said, "… there is a very good risk that the slope instability will be reactivated, especially if wet weather would occur." 55 The defendants did not seek the plaintiff's permission to enter onto her land to carry out this work. The permission which the plaintiff's solicitor had given on 1 November 2002, referred to in para [39] above, was to enter the plaintiff's land for the purpose of effecting a restoration of the land to the condition it had been in prior to the excavation. That permission had been given at a time when the plaintiff had not been informed that restoring the land to its prior condition was simply not possible. Entering upon the plaintiff's land for the purpose of doing work to enable the Driveway Retaining Wall to carry out its intended function was not something which the plaintiff was asked to consent to, nor did she actually consent to it. It is the second occasion when the defendants trespassed on the plaintiff's land. The defendants concede that these acts amount to a trespass. The Interlocutory Injunction 56 On Friday, 23 May 2003 the plaintiff's lawyers obtained an interlocutory injunction from Hamilton J restraining the defendants from entering onto the plaintiff's land, and from undertaking further works on the plaintiff's land. 57 Once the injunction was obtained, the defendants did not enter onto the plaintiff's land. At the time the injunction was obtained, the Driveway Retaining Wall, and the placing of fill behind it, had been completed in the manner in which the defendants had intended to build it, apart from two items of work. One was placing a final course of sandstone blocks onto the top of the wall. The other was filling and battering behind that final course of sandstone blocks. While the defendants could have placed the final course of sandstone blocks on the wall without any breach of the injunction, they could not have filled and battered the slope behind the final course of blocks without breaching the injunction. Without filling and battering behind the final course of sandstone blocks, the final course of sandstone blocks would not perform its intended task of giving support to the land of the plaintiff and of the defendants. In those circumstances, the defendants did not place the final course of sandstone blocks on the wall. 58 Mr Ray Blinman is a geotechnical engineer who was employed by Mr Brink in 2003. He attended the site on 26 May 2003, and reported to Mr Rodier the same day that, while he assessed that the Driveway Retaining Wall would, on completion, adequately retain the recently slipped lower portion of the plaintiff's land, it would not completely stabilise the land slope above. His report continued: "Extensive, active, pre-existing landslip continues to affect the hillside above the driveway embankment with land areas well into the adjoining lot showing signs of movement with extensive subsoil seepage stemming from well above the slipped region. Such movement poses a significant and direct affect on land down slope, also posing an immediate threat of danger to the public. Danger in the form of probable continued collapse of the upper embankment soils probably causing deposition of resultant spoil over the road surface fronting the site. Once again it is our firm's opinion that all portions of the embankment be stabilised immediately. Continued rainfall presently experienced at the site could lead to continued significant failure of the land surface. The placement of a stop work order over the constructions is in our opinion unnecessarily dangerous, possibly irresponsible. We again conclude that the lower, recently slipped soils will on completion of the current retaining wall constructions be adequately retained. Land upslope of these soils, noted previously by our firm as potentially unstable, also require rectification by further drainage and retaining works." 59 Mr Fennell reported to the plaintiff's solicitor on 27 May 2003. He said, concerning the Driveway Retaining Wall: "Provided that the retaining wall has been adequately designed and constructed and performs to its design intent, it is considered that the construction of the retaining wall, as proposed by Mr Rodier, will result in a risk of instability on the subject site and on Lot 2 in DP597409 of about the same level as that of the risk of instability of the slope prior to the excavation. Coffey has neither checked the design of this wall nor is aware of who designed the wall." 60 The interlocutory injunction was modified by Bryson J on 28 May 2003 so that the carrying out of work on the plaintiff's land with the plaintiff's consent, would not amount to a breach of the order. As so modified, that injunction continues on foot. 61 The plaintiff did not consent to the carrying out of the work which was needed to complete the Driveway Retaining Wall in the manner which Mr Blinman proposed. She consented later, on 18 October 2004, to some somewhat different remediation work (see para [72] below). The Upper Retaining Wall Proposed 62 On 29 June 2003 Mr Blinman wrote a report which recommended that a second retaining wall (which I will refer to as the "Upper Retaining Wall") should be constructed on the plaintiff's property. He gave a prose description of what would be involved in such a wall, and two drawings, one of which showed the layout of the Upper Retaining Wall, the other of which showed a cross-section through it. Those drawings did not purport to be to scale, and were not precise in all respects. For example, the height of the Upper Retaining Wall was shown on the drawing as being between 1.0m and 1.5m. Even this was qualified by the text of Mr Blinman's report, which said, "It is possible that the wall could extend to 2.0m although this would be considered an absolute maximum requirement." His report also recognised a range of measurements within which the wall base width might fall. The July 2003 Open Offer of Settlement 63 On 21 July 2003 the defendants' solicitors made an open offer of settlement of the case. In broad terms, this was that the defendant would complete construction of the Driveway Retaining Wall, and the plaintiff would consent to the completed wall being backfilled with gravel. As well, the defendants would: "3. … re-vegetate in accordance with a landscape plan to be provided by our client but with agreed input from both parties, that portion of the road reserve and the plaintiff's land behind the retaining wall the subject of the area of disturbance. This re-vegetation would include one (or two if required by the plaintiff) advanced specimen gum trees to replace the single gum tree which fell down with the initial collapse. The tree(s) would be "advanced specimens" in the largest tub size reasonably available from a commercial nursery. 4. Either: 4.1 Our client will pay the plaintiff's reasonable costs of and incident to these proceedings as agreed or assessed, including costs up until a date 14 days after the date of this offer. or 4.2 Our client makes this proposal to the plaintiff in the alternative to the proposal to pay the plaintiff's costs. Our client sees the convenience and practicality to your client in having the other landslip problems existing on her own land as referred to in the report of Brink & Associates of 26 May 2003 (see attached at para 4) rectified whilst our client has available the necessary machinery and workmen doing the work on the road reserve and the plaintiff's land below (and whilst there is available access from the defendants' land). The work would be done in accordance with the attached report dated 29 June 2003 from Brink & Associates which gives specifications and a plan for the retaining wall necessary to rectify the pre-existing landslip affecting the hillside above the driveway embankment within the plaintiff's land. Notes on this alternate offer: One of the advantages for your client in this work being done in this way is that all of the work and all of the re-vegetation necessary associated with the work could be done at the one time. Our client's proposal is put in the spirit of compromise in this context. Our client believes that the costs of doing the work on the plaintiff's land, totally unrelated to the collapse below referred to in 1 to 3 above (as per Brink & Co report dated 26 May 2003 para 4), will be a sum of money in excess of what we estimate to be the plaintiff's reasonable costs to date. We give the plaintiff the choice of accepting responsibility for this other problem on her own, and the defendant will simply pay the plaintiff's reasonable costs to date. Alternatively, the plaintiff can take up this proposal which, with respect, we suggest to you is a very practical and appropriate proposal, extending the hand of friendship between neighbours in circumstances where neighbourly relations are necessary to deal with the pre-existing problems with the plaintiff's land. 5. Our client will construct stairs giving access on the road reserve in accordance with the enclosed plan. …" 64 The "enclosed plan" was one which showed a set of stairs descending from land immediately to the south of the top of the Driveway Retaining Wall to ground level. The location of those stairs falls within the Council's road reserve, not within the plaintiff's land. 65 The offer was said to be open for acceptance for a period of 14 days from the date of the letter. The letter recognised that implementation of the offer would require the plaintiff to consent to the defendants making the necessary applications to the Council concerning the stairs, and concerning the retaining wall on the plaintiff's land, if she wanted to take up the alternative in para 4.2 of the letter. 66 The letter also stated that if one of the alternative offers made by it was not accepted, the letter would be relied on, "1. in our client's general defence of the proceedings 2. in defence to any claim for costs by the plaintiff for costs incurred after 14 days from the date hereof 3. in a claim for costs against the plaintiff, including indemnity costs if the court agrees, for costs incurred by the defendant after 14 days from the date hereof." 67 On 7 August 2003 the plaintiff's solicitors replied, saying that the offer was rejected. The plaintiff's solicitor said: "We say that the offer you have made is simply too convoluted, too complicated and in any event, we are not in a proper position to advise our client for the following reasons:- (a) Any proposed offer would need to involve the local authority in the deliberations as they are the relevant consent authority and have been joined in the proceedings. (b) We are waiting receipt of further expert evidence to enable us to assess the damages that would consequently flow from your client's behaviour and activities. Once we receive this expert evidence, we then will obtain certain further evidence as to the cost of rectification of the works. (c) In addition, we are in the process of filing an Amended Statement of Claim which will include counts for trespass, removal of right of support pursuant to provision of section 177 of the Conveyancing Act and right of access. You should advise your clients that all of these heads of claim pleaded are serious matters and that substantial damages will probably flow, particularly in relation to the issue of trespass and right of access. In that regard the writer refers you to the decision of TCN Channel 9 Pty Ltd v Henry Alfred Anning 2002 NSWCA 82 … Nonetheless, our client is desirous of settling this matter but not on the basis put by you in your letter of 21st July 2003. It is quite clear that any settlement proposals will have to involve the Third Defendant and following careful consideration of our client's position. At this stage we will not make a counter proposal, but intend to in due course." 68 On 1 September 2004 the parties attended a mediation, which did not result in any settlement. 69 On 6 September 2004 the plaintiff instructed Mr Colenbrander, a geotechnical expert, to provide some advice. After Mr Colenbrander was engaged, the plaintiff did not seek any further assistance from Mr Fennell. Mr Fennell, by the time of the hearing in this case, was engaged as an expert witness by the defendants. The October 2004 Joint Experts Report 70 On 15 October 2004 Mr Blinman and Mr Colenbrander met on site. They prepared a joint report, in which they agreed: "… 3. The current slope instability on No 27 was triggered by the driveway excavation. Slope instability has progressed further uphill since the May 2003 failure, as the slope has not been stabilised. … 5. The sandstone block retaining wall, as constructed, does not support the full soil face in its current state. A 1.5m vertical soil face is exposed below the tree stump at the back face of the trimmed slip scarp. 6. The existing retaining wall is up to 3.2m high and should not be raised above this height. 7. The slope behind the retaining wall is currently unstable and a second retaining wall is required to retain the soil slope. 8. The second retaining wall needs to be constructed as a matter of urgency. 9. The sandstone block upper retaining wall design proposed by Brink in their report dated 29 June 2003 is insufficient to stabilise the slope in its current condition. … 13. If a retaining wall is not to be erected in the short term, then temporary remedial action should be taken as follows: · Remove obvious failed material from the slope. · Trim the slope to minimise rainfall infiltration and facilitate stormwater runoff. · Cover the trimmed slope with woven geotextile sheeting (such as Polytrac 100 as supplied by Geofabrics Australia) and secure the sheeting to the slope." 71 There was one point upon which they disagreed. Mr Blinman was of the opinion that the Upper Retaining Wall referred to in his letter of 29 June 2003 would have been sufficient to stabilise the slope above it if it had been constructed at the time it was designed. Mr Colenbrander, however, was of the view that that wall would never have been sufficient to achieve that purpose. 72 On 18 October 2004 the plaintiff gave permission for the defendants, their servants and agents to come onto her land to carry out the temporary works which the experts had recommended. Her solicitor asked for confirmation, by noon the next day, that the defendants would do that work at their own expense. 73 However, that confirmation was not forthcoming. 74 Then there was some more rain. On 8 November 2004, after that rain, the plaintiff noticed that another slippage had taken place. 75 In February 2005 the temporary works to which the plaintiff had consented were carried out. The Expert Geotechnical Evidence 76 Four geotechnical experts gave evidence in this case. Mr Colenbrander gave evidence for the plaintiff. Both Mr Blinman and Mr Fennell gave evidence for the defendants. As well, the Council had a geotechnical expert, Mr Robert Barker. Mr Barker made his first inspection of the site in December 2004. Hence, like Mr Colenbrander, he came on the scene well after the May 2003 slippage had occurred. 77 The four experts conferred together on two occasions - 9 March 2006 and 21 March 2006 - and on each occasion produced a joint report. Those conferences were valuable in narrowing the issues in dispute. The oral evidence of the experts was taken concurrently, using the "hot tubbing" procedure authorised by Rule 31.26 Uniform Civil Procedure Rules 2005. 78 The experts have reached consensus in their reports on the following propositions:

(a) It is not possible to reinstate the topography between Surf Rider Avenue and the eastern boundary of the plaintiff's land to the condition existing prior to the excavation of the driveway to the defendants' land

(b) It remains possible to provide pedestrian access from the plaintiff's land to Surf Rider Avenue even if the defendants' driveway and the Driveway Retaining Wall remain in place

(c) On the assumption that any modification to existing structures within the road reserve which are required to be made to facilitate access to a carparking area within the plaintiff's land may be undertaken, there is no geotechnical reason to prevent carparking that is planned and built in accordance with the Council's requirements from being constructed in the lower section of the plaintiff's land

(d) The construction of the defendants' driveway and retaining wall has not increased the geotechnical difficulty of constructing carparking within the plaintiff's land

(e) If the provision of carparking on the plaintiff's land is not implemented concurrently with the construction of the necessary stabilisation works concerning the plaintiff's land, then it is likely to incur additional costs

(f) The work done by the defendants up to the end of May 2003 did not improve the slope stability factor and/or support to the plaintiff's land to a condition equivalent to that prior to the cut being made. 79 The experts have agreed that three different approaches are technically feasible, if one wanted to stabilise the plaintiff's land completely. Those three approaches are referred to as Option 1, Option 2 and Option 3 in their joint report arising out of the conclave on 21 March 2006. Option 2 is considerably more expensive than the other two options, and no party advocated its adoption. 80 Option 1 involves, in broad terms, strengthening the Driveway Retaining Wall by improving its foundation, increasing it in height by 500mm, and increasing its mass by placing concrete, at least 300mm thick, and rising to the full height of the wall, immediately behind it. Fill would then be placed on the plaintiff's land, battered between the top of the retaining wall, and meeting the existing ground level in the vicinity of the line of the back scarp. The angle of the slope so obtained is such that it would not slip. 81 Option 3 involves making an improvement to the foundation of the Driveway Retaining Wall, but otherwise leaving that wall in its existing condition. As well, a variant of the Upper Retaining Wall proposed by Mr Blinman would be constructed. It would be constructed by excavating a foundation to rock immediately in front of the back scarp on the plaintiff's land, constructing a concrete levelling pad/shear footing, building a sandstone block wall 3m high across the entire width of the property, placing compacted granular fill/drainage layer behind the wall, providing subsoil drainage from the rear of the wall, and reinstating the ground level in front of that wall. The soil batter between the top of the Driveway Retaining Wall and the toe of the new wall would then be reshaped, in a way which lessened the angle at which it fell between the two walls. 82 The engineers agree that Option 1 would cost $33,000 including GST, and Option 3 would cost $33,500 including GST. Neither option would prevent a carparking space from being constructed on the plaintiff's land, if she so desired. 83 In oral evidence, the experts all agreed on the following further propositions:

(a) as a general proposition for geotechnical assessment, the description "high risk site" means that work must be done on that site to bring it to a lower form of risk;

(b) the plaintiff's land was a high risk site before the cut was created in October 2002;

(c) before October 2002 work needed to be done to stabilise the plaintiff's land even above the Hutchison Line;

(d) the plaintiff's property remains at the least a high risk site at March 2006 (and might possibly be a very high risk site, according to Mr Colenbrander and Mr Barker);

(e) it would have been patently obvious to experienced geotechnical engineers, prior to October 2002, that the plaintiff's site needed slope stabilisation works. In that sense, there was no latent defect in the land.

(f) Option 1 and Option 3 will each turn the plaintiff's land from being at least a high risk site, into a satisfactory state of risk, so far as geotechnical matters are concerned, provided that any areas of the plaintiff's land affected by the slip or the restoration works is revegetated;

(g) the purpose of the version of the Upper Retaining Wall in Option 3 is to retain the land above the Hutchison Line, and also to enable the batter slope on the downhill side of that wall to become less steep. 84 Mr Blinman and Mr Fennell are of the opinion that the Hutchison Line is the line of demarcation, as one moves westerly in the plaintiff's land, of the effect of the October 2002 cut (and, I take to be inherent in their evidence, of the May 2003 slippages). There are some tension cracks in the land to the west of the Hutchison Line. Mr Colenbrander and Mr Barker both regard it as an open question whether those tension cracks were caused by the October 2002 cut (and, I take to be inherent in their evidence, its aftermath). In that state of the evidence, I conclude that the plaintiff has not established that the effect of the October 2002 cut and its aftermath went any further westward on her land than the Hutchison Line. Did the February 2005 Work Rectify the Damage 85 There are some questions of substance on which the experts continue to disagree. One of them is whether the February 2005 work improved the slope stability and/or support on the road reserve and the plaintiff's land to a condition equivalent to that prior to the cut being made. Mr Blinman and Mr Fennell are of the opinion that it did. Mr Colenbrander is of the opinion it did not. Though Mr Barker was initially of the opinion that it did not, in the course of cross-examination he modified that opinion.

Onus 86 Before discussing the basis which the experts had for their various views, I should mention the role which is played in this litigation by the question of whether the February 2005 work improved the slope stability and/or support on the road reserve and the plaintiff's land to a condition equivalent to that prior to the cut being made. The defendants contend that prior to the cut being made the plaintiff's land had a very high risk of slippage, that the February 2005 work put it back into a condition no worse than it was in before the cut was made, and hence that the plaintiff is not entitled to damages measured by the cost of restoration of, or diminution of value in, her land. 87 The defendants bear the onus of establishing the facts necessary to make good that contention: Simonious Vischer & Co v Holt & Thompson [1979] 2 NSWLR 322 at 361; Monroe Schneider Associates Inc v No 1 Raberem Pty Ltd (1991) 33 FCR 1 at 29.

Mr Blinman and Mr Fennell's Reasons 88 The reasons of Mr Blinman and Mr Fennell included that the slope immediately behind the Driveway Retaining Wall had been measured after the February 2005 work at 29º, whereas parts of the slope prior to the collapse were more than 30º. As well, the slope after the February 2005 work was an engineered slope, rather than a natural slope. The lower angle of slope, and being engineered, were each improvements. While the February 2005 work still left a portion of the back scarp unsupported, prior to the collapse the back scarp had been completely unsupported.

Mr Colenbrander's Reasons - Greater Slope Angle 89 One factor which influenced Mr Colenbrander in concluding that the February 2005 work had not restored the pre-existing slope conditions, involved his understanding of the slope of the land prior to the cut being made. On the basis of a plan which Mr Fennell had drawn on 24 July 2003, a time before Mr Colenbrander was engaged, he concluded that the angle of the slope was 25º. I am satisfied that the 25º on Mr Fennell's plan related to a location on the plaintiff's land which was behind the back scarp, and that one could not infer that the land between the location of the Driveway Retaining Wall and the back scarp also sloped at 25º. Mr Colenbrander calculated the angle of the slope after the February 2005 work as being 30º. Having a slope of 30º after the February 2005 work was, he reasoned, a less satisfactory situation, so far as stability was concerned, than a 25º slope. But when there is not a satisfactory basis for concluding that the relevant slope was 25º before the cut was made, this reason of Mr Colenbrander cannot be accepted.

Mr Colenbrander's Reasons - Vegetation 90 Another factor which influenced Mr Colenbrander was that prior to the cut being made, the slope above it was vegetated. The April 1988 landslip occurred in a month when 575mm of rain fell, over 19 days. The May 2003 landslip occurred during a month when 345mm of rain fell, over 20 days. Between April 1988 and May 2003, there had been nine separate months in which the rainfall exceeded 345mm, yet the bank had not collapsed during those months. A report he wrote in May 2005 says that after the 1988 landslip: "The vegetation that subsequently grew over the disturbed area would have assisted in improving the slope stability. The 'reinforcing' effect of the vegetation would have improved with time, particularly if slope movement was small." 91 He provided an academic paper which confirmed that vegetation roots improved soil stability. Mr Colenbrander's report concluded that before October 2002 the slope achieved a quasi equilibrium condition, and that adequate natural slope reinforcement occurred to enable the face to remain essentially intact. 92 Mr Blinman rejected that conclusion, saying: "This is ridiculous. Instability is known to have pre-existed the Rodier excavations and even well vegetated slopes can be unstable. Should vegetating a slope well be the answer to instability prevention then Geotechnical Consultants would be replaced by Landscape Gardeners."

This response has in it an implicit acceptance that vegetating a slope improves its stability to some extent, even if it might not be sufficient to make it completely stable. 93 After the February 2005 work some grass and weeds have grown on the area that was filled, but not the same amount and types of vegetation as existed before October 2002. I accept that, insofar as the slope was not fully revegetated after the February 2005 work, one factor which had contributed to the degree of stability which it had prior to October 2002 was absent.

Mr Colenbrander's Reasons - Adequacy of the Driveway Retaining Wall 94 Another factor which influenced Mr Colenbrander's view is that he was not satisfied that the Driveway Retaining Wall was structurally adequate to support a 30º slope above it. 95 Even though the question of the adequacy of the structural design of the Driveway Retaining Wall was raised in expert reports exchanged between the parties well in advance of the hearing, no plans or calculations to demonstrate the structural adequacy of the wall were placed in evidence. A letter dated 16 January 2006 from an engineer, Mr Thitchener, to Mr and Mrs Rodier was in evidence. He expresses the view that, based on some (unspecified) observations he made on a site inspection and details shown in a cross sectional drawing which Mr Blinman had produced, that the wall was structurally sound and capable of supporting the excavation embankment. He gave no more detailed reasons for that view, and was not called as a witness. Even considered in isolation, Mr Thitchener's opinion is less than persuasive (cf Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705). Mr Colenbrander and Mr Barker, who were called, continued to express their doubt about the adequacy of the wall. 96 In January 2003 a plan, prepared by Mr Thitchener's firm, had been sent to the Council. It related to a retaining wall on the driveway. However, that retaining wall was a boulder wall where it was built on the land of the defendants, and a reinforced concrete retaining wall where it was built on the road reserve. It is simply not the same wall as was actually built in May 2003. The speed with which construction of the Driveway Retaining Wall was commenced after the collapse in May 2003 (the first part of the collapse occurred on 14 May, and the wall was under construction on 21 May) in itself creates ground for wondering whether the wall was an engineer designed one. There is no evidence of the Council having been informed that the wall would be constructed, let alone that it consented to the wall being constructed.

Mr Barker's View 97 I mentioned that Mr Barker in cross-examination had modified the view he had initially expressed about whether the February 2005 work restored the land to the same condition it was in prior to October 2002. The modification was that, on the assumption that the Driveway Retaining Wall is adequate to support the matter that is behind it, and that the pre-existing batter slope was steeper than the one after the Driveway Retaining Wall was put in, he would accept that the February 2005 work had restored the land to a condition no worse than it had previously been in. When the first of his assumptions has not been established, the conclusion he drew based on that assumption has not been established either. 98 In all these circumstances, I am not satisfied that the defendants have established that the Driveway Retaining Wall was structurally adequate to support the slope behind it. As well it was not vegetated to a condition equivalent to what it had been in prior to October 2002. For both these reasons I am not satisfied that the defendants have shown that the February 2005 work restored the slope to the condition of stability which it had prior to October 2002.

How to Give the Driveway Retaining Wall Structural Integrity 99 In cross-examination, Mr Colenbrander accepted that if part, but not all, of the work required to carry out Option 1 were to be carried out, that would remove his concern about the structural integrity of the wall. The specific part of Option 1 which would remove that concern is the part described as: " Provide a reinforced concrete shear key at the toe of the wall secured to the underlying rock strata and into the face of the bottom course of blocks. · Increase the mass of the wall by providing a minimum of a 300mm wide, full height thickness of mass concrete at the rear of the wall, cast integrally with the back of the blocks. The wall may need to be partially demolished and then rebuilt progressively to enable this to be constructed." 100 In other words, his concern would be alleviated without carrying out those elements of Option 1 which involve increasing the height of the wall, and placing fill, appropriately battered, behind the extra height of wall so obtained. I accept that evidence of Mr Colenbrander. 101 I also accept that if the work described in para [99] above were done, and the slope was revegetated, the condition of the slope would be no worse than it was before October 2002. The Claim in Nuisance 102 The basis of the claim for nuisance is that the excavation in the road reserve is conduct of the defendants which has substantially and unreasonably interfered with the plaintiff's use and enjoyment of her land. Even though the road reserve was the land of the Council, a person who, by his or her activities on one parcel of land creates a nuisance on the plaintiff's land can be liable for the nuisance, whether or not he or she is in occupation of the land from which it emanate: (Fennell v Robson Excavations Pty Ltd [1977] 2 NSWLR 486; Pantalone v Alaouie (1989) 18 NSWLR 119 at 129), at least if the person who creates the nuisance is present on the land with the authority of its occupier. 103 In the present case, not only did the defendants have the same implied authority as any member of the public would have from the Council to be on the road reserve, as well the Council had approved the defendants carrying out work there for the purpose of constructing a driveway. Thus, they were present on the land with the authority of the Council, even though what they were doing on that land differed from the work that the Council had approved. 104 Section 177 Conveyancing Act 1919 was inserted in 2000. It provides: "(1) For the purposes of the common law of negligence, a duty of care exists in relation to the right of support for land. (2) Accordingly, a person has a duty of care not to do anything on or in relation to land (the supporting land ) that removes the support provided by the supporting land to any other land (the supported land ). (3) For the purposes of this section, supporting land includes the natural surface of the land, the subsoil of the land, any water beneath the land, and any part of the land that has been reclaimed. (4) The duty of care in relation to support for land does not extend to any support that is provided by a building or structure on the supporting land except to the extent that the supporting building or structure concerned has replaced the support that the supporting land in its natural or reclaimed state formerly provided to the supported land. … (8) Any right at common law to bring an action in nuisance in respect of the removal of the support provided by supporting land to supported land is abolished by this section. …

(12) A reference in this section to the removal of the support provided by supporting land to supported land includes a reference to any reduction of that support." 105 Insofar as the plaintiff seeks to have the stability of her land restored to the condition it was in before the defendants' activities in the road reserve, her claim for damages is "in respect of" the removal of the support provided by the road reserve to her land. That is because it is the removal of support which brought about the need to have the stability restored. Thus, the plaintiff has no cause of action for nuisance concerning that type of damage, but instead has the action in negligence that arises under section 177 Conveyancing Act 1919. 106 The plaintiff's counsel submitted that there was a head of damage, not dependent upon loss of support, which was compensable in nuisance. This was the plaintiff losing access to a public road, firstly by the excavation and secondly by construction of the Driveway Retaining Wall. 107 In Walsh v Ervin [1952] VLR 361 at 362 Sholl J said: "The plaintiff as the owner of freehold land adjoining the road, which was and is a public highway, had and has a right (subject to any statutory interference therewith) to free and uninterrupted access to the highway from any point on his land contiguous with the highway, and from the highway to any point on his land contiguous therewith. This is a private right, which the plaintiff enjoys as an adjoining landowner …It is not to be confused with, and is in fact quite distinct from, the public right which he or any other member of the public has to use the surface of the highway itself for the purpose of lawfully passing and repassing thereon …"

(Citations omitted) See also Shellharbour Municipal Council v Rovili Pty Ltd (1989) 16 NSWLR 104, at 108-109 per Clarke JA. That private right of the plaintiff concerning her land is one which is protected by the tort of nuisance. 108 It is only a substantial and unreasonable interference with the right of access which amounts to the tort of nuisance. 109 One aspect of deprivation of access of which the plaintiff complained is that the construction of the Driveway Retaining Wall inhibits the manner in which she can construct carparking on the lower part of her land. She has never had any specific plans for constructing carparking, and does not claim to have any specific plans to construct carparking on that part of the land now. There is no evidence that it is of importance precisely where on the lower part of the plaintiff's land that carparking is provided, or precisely how the carparking is accessed from Surf Rider Avenue. Even so, she says, the potential use she could make of her land has been interfered with. 110 The expert witnesses agree that the presence of the Driveway Retaining Wall does not prevent the construction of carparking on plaintiff's land. There is no evidence that constructing carparking, when the driveway and Driveway Retaining Wall are in place, would be any more expensive than it would have been if the driveway had never been built. (The engineer's proposition, recorded at para [78(e)] above, is to do with the relative expense of constructing carparking at the time of future restoration works being done or after those works are done, which is a different matter.) Mr David Kettle is a town planner who has practiced in the Gosford area for some decades. He has given evidence that there would be a high likelihood of obtaining development consent for one of three different proposals which Mr Barker put forward, as means of providing carparking on the lower part of the plaintiff's land, subject to a case being made for the need for such additional carparking being required in addition to the carparking which already exists on the plaintiff's land. 111 Mr Kettle also expresses the view that it is unlikely that residents or guests would wish to climb to the house on the plaintiff's land from carparking provided on Surf Rider Avenue, when alternative, relatively level, parking is available on Table Top Road. He was not cross-examined on these opinions, and I accept them. In those circumstances I am not satisfied that the plaintiff has suffered any substantial injury in the form of access to her land for the purpose of carparking being inhibited. To the extent that the presence of the Driveway Retaining Wall limits the places on her boundary across which access to that carparking could be provided, I am not persuaded that this involves an unreasonable restriction on the use of the plaintiff's land. 112 Removal of the steps which formerly gave access from Surf Rider Avenue to the track which led to the plaintiff's land, and construction of the sandstone wall, have prevented the plaintiff and anyone she authorised from using the same track which she formerly followed to reach Surf Rider Avenue on foot from her land. It is common ground that to walk to the beach at North Avoca from the plaintiff's premises takes between 4 and 10 minutes longer if one leaves the plaintiff's land from Table Top Road, rather than from Surf Rider Avenue. The lower figure is one Mr Rodier obtained when he walked the two routes, while the higher figure is one the plaintiff obtained. Mr Rodier is younger than the plaintiff and in an occupation that accustoms him to physical activity. I accept the plaintiff's figures as being how long the two walks take her. 113 The plaintiff, since 1998, has operated a bed and breakfast establishment at her home. The plaintiff gave evidence which was not challenged in cross-examination that she had "always enjoyed pedestrian access to Surf Rider Avenue" and from there to North Avoca Beach. Mr Bech gave evidence in similar terms. That evidence is imprecise. There is no evidence of the plaintiff or her guests having used the steps with any frequency. The plaintiff estimates that it takes 10 minutes to walk from her Surf Rider Avenue entrance to North Avoca beach. Having seen the terrain on a view, it is not an easy walk. Taking into account both the nature of that walk, and the steepness of the plaintiff's block itself, it seems to me that only a person prepared to have some fairly strenuous physical exercise would choose to get to the beach that way. 114 Even so, deprivation of the pedestrian access is still an interference with the plaintiff's property rights. Given the steepness of the drop from the plaintiff's land to the bitumen, and the presence now of the Driveway Retaining Wall, the defendant's activities have effectively prevented the plaintiff from having pedestrian access to Surf Rider Avenue. That makes the interference a substantial one, and, in my view, an unreasonable one. The experts agree that pedestrian access could be reinstated by construction of a set of steps. 115 I accept Mr Kettle's evidence that he is not aware of any specific planning controls that relate to, nor would prevent, development approval of the stairway in the road reserve which would enable the plaintiff to have pedestrian access to her land. 116 But the cost of constructing those steps is not established by any precise evidence. 117 In The Commonwealth v Amann Aviation Pty Ltd (1991) 174 CLR 64 at 83 Mason CJ and Dawson J said: "The settled rule, both here and in England, is that mere difficulty in estimating damages does not relieve a court from the responsibility of estimating them as best it can. Indeed, in Jones v Schiffmann (1971) 124 CLR 303, at 308 Menzies J went so far as to say that the "assessment of damages ... does sometimes, of necessity involve what is guess work rather than estimation". Where precise evidence is not available the court must do the best it can." (some citations omitted) 118 While the defendant's open offer had proposed to the plaintiff to construct a set of stairs, of a kind which a carpenter or metal fabricator would make, all that the plaintiff originally used was the type of steps which I have earlier described in para [18]. The plaintiff has not proved that anything more elaborate than what she previously had is needed to enable her to have access to the bitumen once more. The plaintiff had the onus of proving the element of her damages relating to the cost of the steps. When she has not done so with any precision, but it is obvious that some cost is bound to be involved in replacement of the steps, the approach for the court to take, consistently with the law concerning onus of proof, and fairness to the defendant, is to award the amount of damages based on the low end of the range in which the possible cost of replacing the steps might lie. I assess that at $500. 119 The plaintiff has been deprived of pedestrian access to Surf Rider Avenue since October 2002, a period of around 3½ years. The law of nuisance recognises that damages can be awarded for that sort of inconvenience concerning the use that a plaintiff may make of his or her land. In Bone v Seale [1975] 1 WLR 797 at 804-5 Scarman LJ said: "Nuisance is a wrong to property, but it is well recognised that even when there is no physical damage to property it may cause annoyance, inconvenience and discomfort to the occupier of the property in his enjoyment of it. As Mr McGregor says in MacGregor on Damages , 13th ed (1972), para 1063, when there is a claim for damages in respect of non-pecuniary loss caused by nuisance, recovery of damages is allowable and may be regarded as part of the normal measure of damages. In such a case as this, therefore, we are thrown back to general principles. What is the relevant general principle? I think it is that to which Lord Morris of Borth-y-Gest referred in the course of his speech in H West & Son Ltd v Sheppard [1964] AC 326, 346. That was a case of very severe personal injury, but, speaking of the difficulty of awarding damages where there is no financial yardstick, he said simply: "All that judges and courts can do is to award sums which must be regarded as giving a reasonable compensation." Such is the principle, but the difficulty remains: what is reasonable? … there is very little guidance in the case law." 120 His Lordship referred to one case, decided in 1961, in which £200 was awarded for what struck his Lordship as "a gross interference with comfort and enjoyment of property over a period of five years or thereabouts", arising from noise and smell. He said that other assistance of a general kind could be derived by going " … to personal injury litigation and [noting] the sort of figure that judges award for the element of loss of amenity … It is not, I think, possible to say that we must adopt, or seek to adopt, any rigid standard of comparison between a nuisance case and personal injury litigation. Nevertheless overall, the law ought to remain consistent when it is dealing with analogous situations." 121 His Lordship also referred to: " … a further general principle, that when one is removed from the world of pecuniary loss and is attempting to measure damages for non-pecuniary loss, an element in reasonableness is the fairness of the compensation to be awarded. There must be moderation; some attention must be paid to the rights of the offending defendant as well as to the rights of the injured plaintiff." 122 Those principles have been accepted by Harris J in Oldham v Lawson (No 1) [1976] VR 654 at 658 and by Gillard J in Stockwell v Victoria [2001] VSC 497 at [483]. In Hunter v Canary Wharf Ltd [1997] AC 655 at 698 Lord Lloyd of Berwick referred to the pages of Bone v Seale at which these remarks occur without disapproval. I also accept those principles.

123 Applying the principles in the present case, I assess the damages for the inconvenience at $500. 124 In estimating the amount of damages concerning the cost of replacing the steps, I also take account of the vicissitudes. There is no evidence that the plaintiff, or any of her predecessors in title, had permission from the Council to construct the steps in the road reserve, or that the Council would permit them to remain. One possible threat to the continued use of the stairs was if the Council decided to extend the crib wall further along Surf Rider Avenue. Mr Colenbrander gave evidence that one way in which the plaintiff might have remedied the slip problems on her land, if the defendants had not committed their torts, was by herself extending the crib wall. However, the steps had remained there for many years. I would put the prospect of the plaintiff in future ceasing to have use of the steps, independently of the activities of the defendants, as being 5%. Taking those vicissitudes into account, the damages actually awarded concerning the cost of replacing the steps are $475. 125 Thus, the total damages awarded for nuisance are $975. Failure to Mitigate 126 I now consider the defendants' contention that the plaintiff has failed to mitigate her damage by accepting their open offer. 127 The first element of the open offer was to have the Driveway Retaining Wall completed by placing the final course of block work on it, and backfilling and revegetating. In my view, the plaintiff was acting reasonably in not immediately accepting that element of the offer. At that stage, she had not been provided with information which would give her confidence that performing the work would adequately cure the damage which had been caused to her land. Indeed, at the conclusion of the trial, the defendants have still not established that completion of the Driveway Retaining Wall in this fashion would have prevented the plaintiff from suffering any further damage in consequence of the torts of the defendants. 128 To be able to consider the alternatives in paragraph 4 of the open offer (para [63] above) of paying costs, or having the Upper Retaining Wall constructed, the plaintiff would need to be in a position to evaluate the offer to construct the Upper Retaining Wall. 129 I have already referred to some imprecision in the proposal (para [62] above). As well, the location plan described the Upper Retaining Wall as one "shaped to suit site". While the plan showed the wall extending across substantially all of the plaintiff's land, it did not purport to be to scale, and it did not indicate how far from the plaintiff's eastern boundary it should be constructed, either by measurement, or by description (such as, by saying it should be constructed at the back scarp). 130 One part of Mr Blinman's report of 29 June 2003 said that the foundation excavation should be "in cut earthworks free from filling on its downhill side". However, another part said that the foundation should consist of "either in-situ sandstone or stiff to very stiff residual soil". Mr Blinman's report recognised that the wall: "Will require certification by the designer in order to satisfy Council's requirements. In order to provide such certification the retaining wall constructions will need to be inspected on excavation for wall foundation, at least once during construction and again on completion." 131 Option 3 agreed on by the experts shows the foundation of the variant on the Upper Retaining Wall concept which it put forward as being on rock immediately in front of the back scarp, and with a concrete levelling pad/shear key footing. Mr Colenbrander regarded the possibility of the foundation being in clay as an unsatisfactory aspect of the proposal of 29 June 2003. 132 In my view, the proposal put forward on 29 June 2003 was a concept, worked out in some detail but not enough detail to enable construction to begin immediately. Engineering design work, and site investigation, would be needed before a specification was drawn up which would provide a builder with enough detail to be able to construct the wall, and before one could be confident that the wall would be structurally adequate to perform its intended function. 133 While the element of the offer involving construction of the stairs can now be seen to be sufficient to reasonably satisfy the element of the plaintiff's claim concerning nuisance through loss of pedestrian access, that was only part of an overall offer. Nothing in the offer informed the plaintiff that she could accept those elements of the offer which she wished to accept, and reject the rest. As well, the stairs were proposed to be constructed alongside the Driveway Retaining Wall - and the plaintiff at the time of making the offer could not reasonably have been expected to have decided that she was satisfied with the Driveway Retaining Wall remaining. 134 As well, by the time that offer was made the plaintiff had proceedings on foot to which the Council was a party. Even if the plaintiff accepted that performance of the work proposed by the defendant would cure all the problems with her land, there was still a question about what should be done about the legal costs of the Council. The litigation as a whole could not be disposed of completely without there being agreement concerning the manner in which any costs of the Council would be borne. If the defendants were saying that the work they were proposing would completely cure all problems with the plaintiff's land, there would be, at the least, a question of whether the defendants ought bear the costs of the plaintiff of joining the Council, in a manner analogous to a Bullock order. For all these reasons, the defendants have not established that the offer was one which the plaintiff ought reasonably to have accepted. 135 The defendants had a fallback submission, that even if the open offer was not one which could have been accepted in its terms, the plaintiff ought reasonably to have continued negotiating concerning any aspects of the offer which appeared unsatisfactory to her. 136 In fact, there was a course of correspondence, after the plaintiff had rejected the open offer, by which the plaintiff sought to explore settlement. On 7 August 2003 the plaintiff sought advice from Mr Fennell about the substance of the settlement offer. Mr Fennell sent a report on 15 August 2003, approving the general concept of the Upper Retaining Wall, but saying: "It may be necessary to make a deeper excavation than that proposed in Brink's report in order to achieve suitable founding conditions for such a wall, given that the soil profile affected by instability might be greater than that inferred from observations of exposures on site. Coffey recommends that geotechnical assessment be made of the foundations exposed by excavation for the proposed wall prior to its construction." 137 Mr Fennell proposed three different ways in which prevention of further damage to the property could occur. 138 On 27 November 2003 Carbno MBK, Structural Engineers, sent the plaintiff's lawyers details of retaining wall options of the kind that Mr Fennell had recommended in his report of 15 August 2003. Those details were sufficient to enable a specialist contractor to price and construct either option. 139 Further correspondence related to settlement occurred. I will not reproduce it here, but the documents to which I refer are at page 192A, 192J, and 194-197 of Exhibit B. 140 Before a defendant can establish that a plaintiff has failed to mitigate its damage, the defendant bears the onus of showing that, if the plaintiff had acted reasonably, the plaintiff's damages would have been altogether made good, or made less than they in fact are. A fundamental difficulty in establishing that there has been a failure to mitigate, through the plaintiff not continuing with a course of negotiation, is that the defendant needs to show that, if the plaintiff had continued with that course of negotiation, it is likely that the plaintiff's damages would have been completely satisfied, or lessened. There are inherent difficulties in showing that failure to proceed with negotiations has had that effect. The defendant has not succeeded in showing that in the present case. 141 Neither am I satisfied that the failure of the plaintiff to take more steps than she did to advance the proposal in the open offer amounted to unreasonable conduct on her part. 142 For these reasons, the contention that the plaintiff has failed to mitigate her damage by accepting, or advancing, the open offer, fails. Principles for assessment of damages for tort concerning damage to property: 143 Before turning to the question of damages connected with the loss of support to the plaintiff's land, I consider some general principles concerning the assessment of damages for tort. Relevant principles include:

The compensation principle . An award of damages is intended to compensate the plaintiff for the loss arising out of the tortious act - ie to award the plaintiff a sum of money which, so far as money can do so, will put him in the same position as he would have been if the tort had not been committed: Livingstone v The Rawyards Coal Co (1880) 5 AC 25 at 39; Butler and others v The Egg and Egg Pulp Marketing Board (1966) 114 CLR 185 at 191; Johnson v Perez (1988-1989) 166 CLR 351 at 367; Haines v Bendall (1991) 172 CLR 60 at 63.

The defendant takes the plaintiff as he or she already is . If the plaintiff has some particular susceptibility, so that the consequences of the tort are more serious for the plaintiff then they would be for someone without that susceptibility, the defendant is nonetheless liable for the damage which is caused by the tortious act. This principle applies not only where the damage sustained by the plaintiff is personal injury, but also where it is damage to property: McColl v Dionisatos [2002] NSWSC 276; (2002) Aust Torts Reports 81-652 at [27]-[33].

Damage sustained by the plaintiff before the tort. If at the time the tort is committed the item which the plaintiff claims has been damaged (whether it be an item of the plaintiff's property, or the plaintiff's own body) is already in a defective state, the defendant is not liable for the cost of remedying that defective state: Performance Cars Ltd v Abraham [1962] 1 QB 33; Dillingham Constructions Pty Ltd v Steel Mains Pty Ltd (1975) 132 CLR 323 at 327, 329; Griffiths v Commonwealth of Australia (1983) 72 FLR 260. However it is for the defendant to establish what was that pre-existing state: Dillingham Constructions Pty Ltd v Steel Mains Pty Ltd (1975) 132 CLR 323 at 327. If a plaintiff proves that his or her property has been damaged by the defendant, and the cost of restoration of the property, the onus is on the defendant to disentangle the causes of damage to the plaintiff's property, and establish to what extent the prima facie measure of damage which the plaintiff has thus proved should be reduced by reason of the pre-existing defective state of the property: cf Purkess v Crittenden (1965) 114 CLR 164, at 168.

Betterment. If the only practical way in which the plaintiff can be compensated for damage to an item is by providing the plaintiff with the price of acquiring an item which is better than the item which was damaged, it can sometimes be appropriate to allow the plaintiff the full value of that better item: Harbutt's 'Plasticine' Ltd v Wayne Tank and Pump Co Ltd [1970] 1 QB 447; Dominion Mosaics and Tile Co Ltd and another v Trafalgar Trucking Company Ltd and another [1990] 2 All ER 246; Lumley General Insurance Ltd v Vintix Pty Ltd (1991) 24 NSWLR 652; Optus Networks Pty Ltd v Leighton Contractors Pty Ltd & Ors [2002] NSWSC 327 at [1361]-[1412] (the appeal from which turned on questions other than betterment: Tyco Australia Pty Ltd v Optus Networks Pty Ltd and Ors [2004] NSWCA 333); Hyder Consulting (Australia) Pty Ltd v Wilh Wilhelmsen Agency P/L & Anor [2001] NSWCA 313; Ruthol Pty Ltd v Tricon (Australia) Pty Ltd [2005] NSWCA 443 at [65]. Whether that course is adopted in a particular case depends upon the facts of that case ( Hyder Consulting (Australia P/L v Wilh Wilhelmsen Agency P/L & Anor [2001] NSWCA 313 at [47], [54], [107]), and how best to apply, in light of those particular facts, the fundamental principle that the objective of damages is to put the plaintiff in the same position as he or she would have been if the tort had not been committed. Once the plaintiff has discharged the onus of proving an amount which will remedy his or her damage, the onus of adducing evidence is on the defendant to prove both the presence of any betterment, and also its quantum: J & B Caldwell Ltd v Logan House Retirement Home Ltd [1999] 2 NZLR 99 at 110; Monroe Schneider Associates (Inc) v No 1 Raberem Pty Ltd (1991) 33 FCR 1 at 29; Optus Networks Pty Ltd v Leighton Contractors Pty Ltd & Ors [2002] NSWSC 327 at [1402]-[1407].

Vicissitudes. In assessing the quantum of damages, the court takes into account the vicissitudes of life. These include the chance that events other than the tort might in the future impose the same sort of damage on the plaintiff as the tort has imposed. The way in which the vicissitudes of life are taken into account is by starting with the prima facie measure of damages which would be sufficient to compensate the plaintiff if there were to be no such vicissitudes of life, and then making an adjustment (which usually turns out to be a deduction) for such vicissitudes, to make sure that the plaintiff is not over compensated, or under compensated. For example, a plaintiff seeking damages for personal injuries who seeks compensation for lost future earnings needs to give credit for the prospect that, even if the tort had not occurred, the plaintiff might have had loss of earnings in the future through matters such as illness ( Jobling v Associated Dairies Ltd [1982] AC 794; Malec v JC Hutton Pty Ltd (1990) 169 CLR 638), or even, if it is not so unlikely it can be ignored, being in jail ( Leschke v Jeffs & Faulkner [1955] QWN 67). The process by which a court arrives at an allowance for vicissitudes was explained by Windeyer J, in the context of a claim for personal injuries, in Bresatz v Przibilla (1962) 108 CLR 541 at 543-544: "What it involves depends, not on arithmetic, but on considering what the future might have held for the particular individual concerned. He might have fallen sick from time to time, been away from work and unpaid. He might have become unemployed and unable to get work. He might have been injured in circumstances in which he would receive no compensation from any source. He might have met an untimely death. Allowance must be made for these 'contingencies', or the 'vicissitudes of life' as they are glibly called." 144 In principle, the allowance for vicissitudes need not only be negative: Bresatz v Przibilla (1962) 108 CLR 541 at 544; Norris v Blake (by his tutor Porter) (No 2) (1997) 41 NSWLR 49 at 73. While the context in which deductions for vicissitudes of life is most commonly encountered is in connection with damages for personal injury, making an allowance for vicissitudes is a necessary means of applying the fundamental principle that the objective of damages is to put the plaintiff in the same position as it would have been if the tort had not been committed. As a matter of principle, an allowance for vicissitudes might be appropriate, depending upon the facts of the particular case, for any type of tort. Damages concerning slippage of plaintiff's land 145 In applying those principles here, this plaintiff had a particular susceptibility, in that her land was unusually subject to slip. The defendants are liable to compensate her for the consequences of their torts, even if the actions which they carried out would not have caused any damage to land which did not have that particular susceptibility. 146 The Option 3 works have as their objective both the stabilisation of the plaintiff's land above the Hutchison Line, and also enabling the existing Driveway Retaining Wall to adequately stabilise the land that was affected by the defendants' torts. The Option 3 works are also more expensive than the Option 1 works. For both these reasons the Option 1 works provide a better prima facie measure of the plaintiff's damage than do the Option 3 works. 147 The plaintiff has established that if the Option 1 works were carried out, at a cost of $33,000, and the affected slope revegetated, not only would the slippage which the defendants had caused be rectified, but as well any slippage which might arise in the future by reason of the inherent susceptibility of the land to slip would be guarded against. 148 Even though the plaintiff's land had a susceptibility to slip, insofar as it was a mere susceptibility that had not manifested itself the situation is covered by the principle that the defendant takes the plaintiff as he or she is. Insofar as the land had already slipped, the defendants had no liability to restore that pre-existing slippage. The compensation principle means that if it is in practice possible for work to be done which will restore the plaintiff's land to its pre-existing condition, (defective as it was) all the defendants need pay for is that work. 149 The general principles about the extent of the making good of damage that the plaintiff is entitled to must be applied using the common law's techniques for proof of facts in a trial, and in particular the principles concerning onus of proof and the shifting onus of adducing evidence. 150 While the defendant has established that the land had suffered some pre-existing slippage, and that the limit of the effect of the defendant's conduct was at the Hutchison Line, the defendant has only gone part of the way towards proving to what extent any damages of less than the cost of performing the Option 1 works would put the plaintiff back into the situation she was in before the torts were committed. The defendants have established that if part, but not all, of the Option 1 works were carried out (namely those identified in para [99] above), and the slope were revegetated, the plaintiff would be put into the same position as she would have been in if the tort had not been committed. However, the defendants have not completed the task by proving how much it would cost to do only that part of the Option 1 work. Thus they have not discharged their onus of proving to what extent the prima facie measure of damages, namely the cost of the Option 1 work, should be reduced by reason of the pre-existing defective state of the property. 151 I now turn to apply the principles concerning betterment. Giving the plaintiff the full cost of the Option 1 works will result in the plaintiff's land being in a better situation than it was prior to the torts being committed. The defendant has shown that performing only part of the Option 1 works would suffice to remedy the plaintiffs damage, insofar as it relates to slippage. There is no evidence concerning whether the Council would allow only part of the Option 1 works to be carried out on its land when they would only partly remedy the slippage problems of the plaintiff's land. If the Council would not permit the works to be carried out, and would require the whole of the Option 1 works to be carried out, the situation would arise where the only practical way of remedying the damage which the defendants caused would necessarily involve the plaintiff in receiving betterment. In that situation, the appropriate way of applying the principle of compensation would be to make no deduction on account of the betterment, because the plaintiff could not be compensated without also providing her with the betterment. Even if it were the case that the Council would permit only that part of the Option 1 works to be carried out which would remedy the damage which the defendants caused, the defendants have not discharged their onus of establishing the quantum of the cost of providing any element of betterment, and for that reason it would not be appropriate to make any reduction by reason of the betterment. Thus, in either situation, no deduction should be made by reason of the principle relating to betterment. 152 In deciding that the defendants have not discharged their onus of establishing the quantum of the cost of providing any element of betterment, I considered whether I could conclude that there must be at least some cost involved in carrying out those elements of the Option 1 works which are not necessary to remedy the damage which the defendants caused. I could not reach any such conclusion. That was because thickening the Driveway Retaining Wall by providing concrete behind it would necessarily involve carrying out excavation behind the Driveway Retaining Wall, to a sufficient extent to allow both the concrete reinforcement itself, and any formwork which might be needed to construct the concrete reinforcement, to be placed inside the excavation. If only those works which were needed to remedy the damage which the defendants have caused to the plaintiff's land were to be done, there would be a quantity of excavated material which would need to be carted away (presumably at a cost), and disposed of (presumably at another cost). There is no basis in the evidence for forming any view about how this quantity of excavated material relates to the quantity of material which would need to be placed on the plaintiff's land to carry out the whole of the Option 1 works, whether the excavated material would be suitable to use in carrying out the stabilisation of the plaintiff's land uphill of the Driveway Retaining Wall as part of the Option 1 works, or whether the cost of carting away and disposing of excavated material would be less than the cost of leaving the excavated material on the site in using it in the course of carrying out the whole of the Option 1 works. 153 I turn now to consider the principle concerning vicissitudes. If the defendants had not committed their torts at all, the plaintiff would have had land which was susceptible to slip, both above and below the Hutchison Line. I do not accept that the vegetation on the slope had effectively stabilised the slope by the time the defendants came to commit their torts. After all, all of the experts agreed that it was high risk land, so far as the risk of slip was concerned. Nor was it certain that the vegetation would remain as it was immediately before October 2002. On 14 March 2005 Mrs Rodier saw Mr Bech using an electric chainsaw to cut down growth and trees (with a trunk diameter of up to 100mm) and hacking various pathways through the plaintiff's property leading down slope and across the area in which Mr Fennell had previously mapped the existence of slump scarps. If the defendants had not committed their torts at all, there would still have been a significant risk that the plaintiff's land would slump once again, and bring with it a need for remedial work to stabilise the land. The prospect of the plaintiff's land sustaining damage of this kind is one of the vicissitudes of life for which a deduction from the prima facie measure of damages should be made. No one has suggested, and I have not been able to think of, any positive vicissitudes which could affect the measure of damages. If the defendants had not committed their torts, I conclude that the chances of the plaintiff having to do work, of a value equivalent to that of the Option 1 work, to stabilise her land are about the same as the chances of the plaintiff not having to do such work. I assess the deduction which should be made at 50% of the cost of the Option 1 works. 154 The result is that the amount the plaintiff recovers as compensation for the building work required to rectify the damage caused by the slippage is $16,500. Revegetation 155 It is not contested that revegetation of the area affected by the excavation is a necessary part of undoing the damage which the defendants caused. There is no evidence which deals directly with the cost of revegetating that precise area. Presumably for the purpose of the mediation, the plaintiff obtained a quotation from a landscape design and construction contractor, one element of which was providing vegetation to part of the plaintiff's land which appears, from the plan accompanying the quotation, to lie within the downslope 40% of the plaintiff's land, but above a retaining wall, (called a soldier pile wall) located in a different position to the Upper Retaining Wall. The cost of revegetating the area above that soldier pile wall was estimated to be $1,800. 156 With that as my only guide, I estimate the cost of revegetating the area which would need to be revegetated if the damage to the plaintiff's land were rectified by using the Option 1 method, as being $900. That figure is subject to a deduction of 50% for vicissitudes, as it is part of the cost of rectifying the damage the defendants caused involving the stability of the slope. Thus it reduces to $450. Mental Trauma 157 The plaintiff particularised "mental trauma" as one type of damage which she suffered. She claimed both compensatory damages, and aggravated damages, concerning that mental trauma. 158 It was only in the course of final address that the plaintiff's claim was permitted to be amended to seek aggravated damages insofar as it comprises mental trauma. The plaintiff's claim for relief had always included "damages". The plaintiff had sought, in final address, to widen the prayers for relief to include "aggravated damages". I was not prepared to allow that amendment given that the evidence had concluded, and there had been no pleading of the facts and circumstances which gave rise to any general claim for aggravated damages. I allowed only an amendment to seek aggravated damages insofar as it consisted of mental trauma. I took that course because the plaintiff had already particularised mental trauma as one of her heads of damage, and such evidence as there was on the topic had already been given by affidavit. The effect of the amendment was to permit the plaintiff to recover damages for the "mental trauma" she had already particularised and given evidence about if, as a matter of legal analysis, such mental trauma should be categorised as aggravated damages, rather than compensatory damages. 159 The totality of the evidence which the plaintiff presented on a topic anything like mental trauma was a passage in an affidavit, dealing with events at the time of the making of the initial cut in the land in October 2002. It said: "I was very upset by the works occurring on my land. I had never been asked for permission to enter my land by the Rodiers, the Council or anyone else. I had never been informed that the removal of vegetation, rocks and soil from my land and the removal of the crib wall in the road reserve formed part of the works the Council had approved for the Rodier's land next door. These works were not part of the development proposal that was sent to me. The following day I wrote to the General Manager, Gosford Council …" 160 I accept the evidence which the plaintiff there gives. However, the evidence just quoted suggests that her upset was at least to some extent occasioned by the Council, not by the Rodiers. 161 The plaintiff has not sought to give any detail concerning for how long she was upset, or (beyond "very") her degree of upset. She does not seek to prove that she needed medical treatment, or suffered any medical or psychiatric condition, or indeed any other consequence, as a result of it. 162 In TCN Pty Ltd v Anning (2002) 54 NSWLR 333 at 354, [107] Spigelman CJ (with whom Mason P and Grove J agreed) said, concerning a trespass involved in a media raid on private property. "Humiliation, injured feelings and affront to dignity may be a natural and probable consequence of intrusion by the media of private property. Such damage is compensable as aggravated damages. Such damage is different in kind to mental trauma." 163 It would be erroneous to use that passage to say that, while the plaintiff had established she was upset, she had not established the more serious kind of mental disturbance that counts as mental trauma, and so should receive no damages under this head of claim. To do so would not accord with the intent of the amendment which was permitted. 164 I am not satisfied that such upset as the plaintiff had arose from the trespass on her land, as opposed to the other torts which were committed. The plaintiff's land which was trespassed upon was only a comparatively small part of the land which was involved in the entire excavation. The focus of the plaintiff's complaints at the time was not that there had been a trespass, but that the work might deprive her land of support, para [36] above. 165 I turn to consider whether aggravated damages can be awarded for the torts other than trespass that the defendants committed. There is a question of law about whether aggravated damages can be awarded for nuisance: Willoughby Municipal Council v Halstead (1916) 22 CLR 352; Oldham v Lawson (No 1) [1976] VR 654 at 658-9. 166 There is also a question of law about whether aggravated damages can be awarded for negligence: Kralj v McGrath [1986] 1 All ER 54 at 61 per Woolf J In Kralj, however, Woolf J gave some damages for the very significant mental distress of a mother who had been horrifically treated in giving birth, but did so as an aspect of the pain and suffering component of compensatory damages, and because it was severe enough to amount to nervous shock. In Hunter Area Health Service v Marchlewski (2000) 51 NSWLR 268 at 284 -288, [94] - [111] Mason P (with whom Stein and Heydon JJA agreed) concluded that there is no clear guidance in Australian case law on the availability of aggravated damages in negligence actions but doubted the need for the award of such damages in practice. 167 It is not necessary to resolve either of these questions of law. In my view, the plaintiff has not demonstrated that any upset which she suffered in consequence of the action of the defendants was anything other than de minimis. For all the evidence shows, she might have been very upset for a few minutes and then got over it. Thus she is entitled to neither compensatory damages nor (assuming they are in principle available) aggravated damages for her upset. The Defendants' Offers of Undertakings 168 The defendants have offered to the Court undertakings to do certain work if the Court decided that work is necessary to bring the land into a condition equivalent to the condition it was in before the cut was made. I will not go into the details of those undertakings. Nor will I go into any question of whether the Court has power to accept the undertakings (cf Thomson Australian Holdings Pty Ltd v Trade Practices Commission (1981) 148 CLR 150 at 164-6; ASIC v Edwards [2004] NSWSC 1044; (2004) 51 ACSR 320). I proceed in this way because I do not regard the acceptance of undertakings to perform work as a satisfactory way of resolving the final hearing of a claim for damages for tort. If the defendants were to fail to carry out their undertakings, the only available remedy would be one appropriate to contempt. Obtaining a contempt remedy would not compensate the plaintiff for any loss she had suffered. 169 I recognise that at one stage the plaintiff was claiming a mandatory injunction, to require the defendants to restore the slope to the condition it was in prior to the cut being made. The course of correspondence between the solicitors shows that this was intended to include a claim to have the driveway moved, and the Driveway Retaining Wall dismantled. That claim for a mandatory injunction was abandoned in the plaintiff's opening, and could not have succeeded in light of the unanimous expert evidence that complete restoration of the slope to the condition it was in, is impossible. I do not regard the fact that the plaintiff made this claim as affecting my conclusion about whether the defendants' undertaking should be accepted. Relief Given 170 The plaintiff is entitled to damages totalling $17,925.00, made up of: Item Judgment para $ Compensation for building work 154 16,500 Compensation for revegetation 156 450 Compensation for nuisance concerning loss of pedestrian access 125 975 Total 17,925

171 The plaintiff also makes a claim for interest and costs. It will not be possible to enter a judgment until such time as any argument about interest has taken place and the quantum of any interest has been fixed. 172 Even though the hearing was a hearing on issues apart from the monetary value of any deterioration in the plaintiff's land, it may be that the present judgment removes any need for a further hearing. In broad terms, when there has been a tort infringing a plaintiff's interests in land, damages can sometimes be calculated by reference to the cost of rectification, and sometimes by reference to the diminution in value. This judgment has only sought to deal with the element of damages involving cost of rectification. Ordinarily, however, if damage is capable of remedy, then the measure of damages appropriate to the cost of rectification will also cure any loss of value in the land. In practice, debate about these two alternative ways of assessing damages usually focuses on whether a plaintiff is entitled to cost of restoration, when the loss in value caused by the tort is less than the cost of restoration. Here, the defendants contend that the damages so far as loss of support to the land are concerned, should be measured by reference to the cost of restoration. 173 I have not heard the parties concerning whether any further hearing is needed, and so shall leave open the question of whether one should be provided for. If a further hearing is sought, it would be undesirable to enter a judgment at this stage. 174 The plaintiff has proffered to the Court an undertaking to the effect that she will spend any damages recovered in carrying out the Option 1 works. I see no reason not to accept that undertaking. 175 The only order I make at this stage is to direct the parties to contact my Associate within 14 days of the date of delivery of these reasons to obtain a date for any further argument concerning interest and costs, and concerning whether any further hearing on quantum of damage is necessary. If the parties are able to agree on those matters and submit a draft order, I will make the order in Chambers. If they are not able to agree, they should bring in drafts of their respective contentions concerning the orders which should be made on the date when that further argument occurs. **********

12/07/2006 - Party and Counsel details corrected on coversheet. Typographical error corrected, substituting the word "laid" for "land". - Paragraph(s) 24

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