New South Wales Supreme Court CITATION : Quick v Alpine Nurseries Sales Pty Ltd [2010] NSWSC 1248 HEARING DATE(S) : 19-22 July 2010 JUDGMENT DATE : 29 October 2010 JURISDICTION : Equity JUDGMENT OF : Ward J DECISION : Plaintiffs' claim dismissed with costs CATCHWORDS : PRACTICE AND PRCEDURE - adequacy of pleadings - HELD - claim in negligence has not been properly pleaded and cannot now be maintained - claim in nuisance is limited to pleaded allegations - TORTS - nuisance - whether substantial and unreasonable interference by the defendants with the rights of or in connection with the plaintiffs' use of their land as a result of development and use of defendants' land as commercial nursery - HELD - no unreasonable interference with use or enjoyment of land by defendants as pleaded LEGISLATION CITED : Civil Liability Act 2002 (NSW) Protection of the Environment Operations Act 1997 (NSW) CATEGORY : Principal judgment Bayliss v Lea (1961) 62 SR (NSW) 521; [1961] NSWR 1002; (1961) 79 WN (NSW) 218 Banque Commerciale SA (in liq) v Akhil Holdings Ltd (1990) 169 CLR 279; 92 ALR 53; [1990] HCA 11 Barbagallo v J & F Catelan Pty Ltd [1986] 1 Qd R 245 Bell v Pitt [1956] Tas SR 161 Bennetts v Honroth [1959] SA SR 170 Bone and Anor v Seale [1975] 1 All ER 787 Borough of Bradford v Pickles [1895] AC 587 Brand v Monks [2009] NSWSC 1454 Broadbridge Little v Holroyd (1935) LGR (NSW) 81 Brodie v Singleton Shire Council (2001) 206 CLR 512 Bruce v Odhams Press Limited [1936] 1 KB 697 Cambridge Water Co v Eastern Counties Leather [1994] 2 AC 264 Charter Carter Pty Ltd v The Shop, Distributive and Allied Employees' Association of stern Australia (1987) 13 FCR 413 City of Richmond v Scantelbury [1991] 2 VR 38 Corbett v Pallas (1995) 86 LGERA 312 Delaware Mansions Ltd v Westminster City Council [2002] 1 AC 321 Don Brass Foundry Pty Ltd v Stead (1948) 48 SR (NSW) 482 Douglas v Swan (12 December 1950, unreported) CHECK Elston v Dore (1982) 149 CLR 480 Gartner v Kidman [1962] HCA 27; (1962) 108 CLR 12 Graham Barclay Oysters Pty Ltd v Ryan (2002) 211 CLR 540 Greetings Oxford Koala Hotel Pty Ltd v Oxford Square Investments Pty Ltd (1989) 18 NSWLR 33 Goldman v Hargrave [1967] 1 AC 645 H 1976 Nominees Pty Limited v Galli (1979) 30 ALR 181 Hill v Van Erp (1997) 188 CLR 159 Hunter v Canary Wharf Ltd [1997] AC 655 Ingot Capital Investments Pty Limited v Macquarie Equity Capital Markets Limited (2008) 73 NSWLR 653; (2008) 252 ALR 659; (2008) 68 ACSR 595; [2008] NSWCA 206 Kernel Holdings Pty Ltd v Rothmans of Pall Mall (Australia) Pty Ltd (unreported, French J, Federal Court of Australia, 3 September 1991) Kraemers v Attorney General (Tas) [1966] Tas SR 113 Leakey v National Trust for Places of Historic Interest or Natural Beauty [1980] QB 485 CASES CITED : McFadzean v CFMEU [2004] VSC 289 Melaleuca Estate Pty Ltd v Port Stephens Council [2006] NSWCA 31 Michallef v Galea [2001] NSWSC 984 Montana Hotels Pty Ltd v Fasson Pty Ltd (1986) 61 ALJR 282, at 284, (1986) 62 LGERA Nina Kung v Wang Din Shin [2005] HKCFA 54 Oldham v Lawson (No 1) [1976] VR 654 Odhams Press and Pinson v Lloyds and National Provincial Foreign Bank Limited [1941] 2 KB 72 Overseas Tankship (UK) Ltd v Miller Steamship Co Pty (The Wagon Mound (No 2)) [1967] 1 AC 617 Perre v Apand Pty Ltd (1999) 198 CLR 180 Pride of Derby V British Celanese Ltd [1953] Ch 149 Qantas Airways Ltd v Cameron (1996) 66 FCR 246 Ratcliffe v Evans (1892) 2 QB 524 Re Bega Co-operative Society Ltd & Anor v The Milk Authority of the Australian Capital Territory & Anor [1997] FCA 200 R v Commissioners of Sewers for Pagham, Sussex [1828] EngR 680; (1828) 8 B & C 355, at 361 [1828] EngR 680; 108 ER 1075 Rickard & Ors v Allianz Australia Insurance Ltd & Ors [2009] NSWSC 1115 Robson v Leischke [2008] NSWLEC 152; (2008) 72 NSWLR 98; (2008) 159 LGERA 280 Roberts v Rodier [2006] NSWSC 282 Rubenstein v Truth and Sportsman Limited [1960] VR 473 Sedleigh-Denfield v O'Callaghan [1940] AC 880 Shanmugaratnam v Strasburger Enterprises (Properties) Pty Ltd [2004] NSWCA 229 Smith v Littlewoods Organisation Ltd [1987] AC 241 Solloway v Hampshire County Council (1981) 79 LGR 449 Stockwell v Victoria [2001] VSC 497 Sutherland Shire Council v Becker [2006] NSWCA 344 Trade Practices Commission v David Jones (Australia) Pty Ltd (1985) 7 FCR 109 Travel Compensation Fund v Blair [2003] NSWSC 720 Vairy v Wyong Shire Council (2005) 223 CLR 422 Vella v Permanent Mortgagee Pty Ltd [2008] NSWSC 505 Vines v Australian Securities and Investments Commission (2007) 73 NSWLR 451; (2007) 62 ACSR 1; [2007] NSWCA 75 Xuereb v Viola (1990) Aust Torts Reports 81-012 Woods v Multi-Sport Holdings Pty Ltd (2002) 208 CLR 460 Wyong Shire Council v Shirt (1980) 146 CLR 40 TEXTS CITED : Fleming on Torts, 2nd ed, Clarendon Press, 1961 Young, Croft and Smith, On Equity, Lawbook Co, 2009 Clive Richard Quick (First Plaintiff) Ceridwen Sian Quick (Second Plaintiff) PARTIES : Alpine Nurseries Sales Pty Ltd (First Defendant) Peter Wallace Knox (Second Defendant) Kay Marilyn Knox (Third Defendant) FILE NUMBER(S) : SC 08/281163 COUNSEL : S Philips (Plaintiffs) S A Kerr SC with S Robertson (Defendants) SOLICITORS : Stafford Lawyers (Plaintiffs) Brischetto & Ford (Defendants) IN THE SUPREME COURT OF NEW SOUTH WALES EQUITY DIVISION WARD J FRIDAY 29 OCTOBER 2010 08/281163 CLIVE QUICK & ANOR V ALPINE NURSERIES SALES PTY LTD & 2 ORS JUDGMENT 1 HER HONOUR: Mr and Mrs Quick have brought proceedings against Alpine Nurseries Sales Pty Ltd (Alpine Nurseries), a company which carries on the business of a wholesale plant nursery (the Alpine Nursery) near Lismore, and against Mr and Mrs Knox, who are the registered proprietors of the land on which the business is conducted and the directors and shareholders of the company. 2 Mr and Mrs Quick own land on the northern side of Ellis Road opposite the Alpine Nursery. Broadly, their complaint is as to the adverse impact they say there has been on the use and enjoyment of their land from the operations of the commercial nursery since 2004. They contend that the flow of water from the Alpine Nursery land onto the south-western corner of their land has substantially increased, that the percolation of subsurface groundwater into their land has decreased, and that the quality of the water running onto their land has decreased, as a result of the defendants' alteration of the conformation of the Alpine Nursery land and the use of that land as a commercial nursery. 3 In particular, they attribute the increased volume and velocity of water that they say now arrives at their property to the facts that nursery garden beds now cover a large portion of the front slope of the Alpine Nursery land and have been covered with impervious black plastic sheeting and that the internal roads around those garden beds are covered with compacted gravel, which they claim has reduced the natural absorption of rainwater by the soil and altered the flow of surface water off the Alpine Nursery property, and to the construction on the property of a water storage facility (ie, a dam), which they say artificially retains water and then overflows onto their land. They also blame the introduction of an extensive watering and irrigation system (which they say operates on an almost nightly basis) for the increased water flow onto their land during dry weather. 4 It is alleged that the construction and use of the water retention dam on the front of the Alpine Nursery property and the use of the property as a commercial nursery (with particular reference to the impervious plastic sheeting, intensive irrigation, and the use and spraying of fertilisers, pesticides and other chemicals) constitutes a non-natural use of the property (paragraph 20 of the Amended Statement of Claim). However, and this gives rise to a pleading point raised by the defendants, the basis for the complaint of nuisance (as pleaded in paragraphs 24 and 25 of the Amended Statement of Claim) is limited to the alleged increase in water flow, incidence of flooding and increased water seepage or percolation of water onto the Quick Property, to which I will refer collectively as the alleged 'water flow interference' (and not the other matters referred to in paragraph 20 of the pleading). Mr and Mrs Quick contend that the water flow interference amounts to a substantial and unreasonable (and ongoing) interference with their enjoyment of their land, amounting at law to nuisance. 5 Although Mr and Mrs Quick's principal claim is in nuisance, and the relief on which they are primarily focussed is to prevent the occurrence of future nuisance, they have also brought a claim in negligence in relation to "the matters complained of" (paragraph 29 of the Amended Statement of Claim). This claim also gives rise to a pleading issue. 6 The loss and damage allegedly suffered by reason of the alleged nuisance (and negligence) is particularised in paragraph 28 of the Amended Statement of Claim as the destruction of boundary fences; silting up and pollution of a cattle dam on their property; loss of use of the cattle dam as a water supply and loss of use of the southern paddock (in which the dam is situated); loss of use of rainwater run-off from the roofs of buildings on their property due to air pollution as a result of chemical sprays on the Alpine property; cost of installing an alternative (bore) water supply; lowering of the water table under their property and reduction in volume of water available in bores; loss of enjoyment of their property (arising from pollution, spraying and increased noise and traffic); (unquantified) diminution in the value of their property; loss of (an unidentified number of) trees on the property; and (though this allegation was not ultimately pressed at hearing) personal injury to Mr and Mrs Quick. 7 The defendants deny that they are guilty of nuisance, as alleged or at all, deny the claim in negligence and deny each of the allegations in respect of loss and damage. They further say that paragraph 29 of the Amended Statement of Claim, in which the claim of negligence is made, does not plead a judiciable cause of action; is vague and embarrassing; and should be struck out. 8 In essence, the defendants' position is that surface water has always flowed naturally through the southern paddock of the Quick Property (which is located at the lowest point of the surrounding area); that water flows onto the Quick Property not just from the Alpine Nursery land but from Ellis Road and from the other neighbouring properties; and that the natural watercourse runs from there into an 'unmade' or 'paper road' to Marom Creek. The defendants contend that Mr and Mrs Quick have failed to establish that there has been any material increase in the flow of surface water to the Quick Property or that any increase in water flow has been caused by the defendants. Apart from pointing to the potential impact of the Council's actions in expanding the Ellis Road culvert immediately in front of the southern paddock in November 2005 (which Mr Quick conceded had been the subject of a complaint by him to the Council to the effect that it had made the water flow more quickly onto his property), it was suggested that the current state of the southern paddock (which is frankly conceded by Senior Counsel for the defendants, Mr Kerr, to be a boggy marsh) was attributable to the failure of Mr Quick properly to maintain his land (and the adjoining vegetation corridor) so as to permit the water flowing onto the Quick Property to flow (as it had previously done) off the property and to continue along its normal watercourse down to Marom Creek. 9 By way of relief, the principal focus of Mr and Mrs Quick, as noted above, is on the prevention of apprehended future nuisance (though they also seek compensation for past nuisance – T 70.20). This emerged very clearly in cross-examination, when Mr Quick said that what he was seeking was that nightly irrigation water and small amounts of rain "that would normally soak into property remain on that property as would be expected in a normal farming situation" – T 69.42 (my emphasis); for his paddock to be restored to what it was – T 70.20; and for a guarantee that the water coming onto his property is "clean reliable farm water" – T 70.38, asserting that "We are not responsible for what occurs [downstream] at Marom Creek"). 10 In their Amended Statement of Claim, Mr and Mrs Quick seek an order restraining the defendants from allowing the discharge onto the Quick Property of any water in excess of the natural flow that would ordinarily flow onto their land but for the Alpine Nursery operations and an order that, by a date to be determined, the defendants undertake such remedial or other works as are necessary to prevent the flow onto the Quick Property of any water containing levels of nutrients or chemicals which would amount to water pollution for the purposes of the Protection of the Environment Operations Act 1997 (NSW). They further seek an order that, in default of the above, the defendants cease all nursery operations on the Alpine Nursery property located within that portion of the land which is zoned 7(c) under the Ballina Local Environment Plan) (the water catchment zone). It can be seen that the relief sought in this regard is somewhat similar to that granted in Melaleuca Estate Pty Ltd v Port Stephens Council [2006] NSWCA 31 (2006) 143 LGERA 319; (2006) 12 BPR 23,743; (2006) ANZ ConvR 302 (although Mr Kerr points out that the relief there granted was in the context of an agreed regime for the nuisance to be addressed before the more draconian order for cessation of operations would come into force). Issues 11 The issues for determination are as follows: (i) Whether Mr and Mrs Quick can maintain the claim in negligence made in paragraph 29 of the Amended Statement of Claim and/or any claim in nuisance other than by reference to the matters alleged in paragraphs 24 and 25 of the Amended Statement of Claim (ie by reference to any matters other than the alleged water flow interference). (ii) As to the claim in nuisance, whether there has been a substantial and unreasonable interference by the defendants with the rights of Mr and Mrs Quick in relation to or in connection with the use of their land. In this regard (and assuming for the purposes of (b), (c) and (d) below that there is an affirmative answer to the second of the pleading issues raised in (i) above): (a) has there been a substantial or material increase in the velocity or flow of water (or in the incidence of flooding or water seepage) onto the Quick Property than would have been the case but for the alterations in the conformation or use of the Alpine Nursery land from May 2004? (b) does the evidence establish that water flowing from the Alpine Nursery land onto the Quick Property since May 2004 contained levels of nutrients or chemicals which would amount to water pollution, including for the purposes of the Protection of the Environment Operations Act ? (c) have the defendants performed acts that have had the effect of reducing the amount of subsurface groundwater percolating through the Quick Property? (d) have the defendants otherwise substantially interfered with the plaintiffs' use or enjoyment of their property (ie by reference to noise, aerial spraying or increased traffic)? (iii) If the answer to any part of (ii) is in the affirmative, whether this is a result of the natural use of the Alpine Nursery land. (iv) Whether it is likely that there will be water flow interference amounting to a nuisance in the future (or any other apprehended nuisance, which would give rise to quia timet injunctive relief). (v) Whether, if Mr and Mrs Quick can maintain a claim in negligence, has there been a breach of any duty of care owed by the defendants to Mr and Mrs Quick and, if so, what loss or damage has resulted therefrom. (vi) What remedy, if any, should be granted in light of the findings in respect of the above matters. Summary 12 For the reasons set out below, I am of the view in relation to the above issues that: (i) The claim in negligence has not been properly pleaded and cannot now be maintained. The claim in nuisance is limited to a claim based on the alleged water flow interference pleaded in paragraphs 24 and 25 of the Amended Statement of Claim and cannot be maintained in relation to any complaint as to the quality of the water flowing onto the Quick Property, the reduction in the subsurface groundwater or other matters such as the alleged air pollution, noise and increase in traffic to and from the Alpine Nursery land. Further, the claim in nuisance is as to the water flow interference allegedly caused by or as a result of the alteration to the conformation and use of the property as pleaded in the paragraphs preceding paragraphs 26 and 27 of the Amended Statement of Claim (and not as a result of any other alteration to the conformation of the land such as the creation of the ridge or levy bank along the eastern boundary of the Alpine Nursery land). (ii) I am not satisfied that there has been a substantial and unreasonable interference by the defendants with the use or enjoyment by Mr and Mrs Quick of the Quick Property as pleaded. In particular: (a) I am not satisfied that there has been a material or substantial increase in the velocity, flow or percolation of water from the Alpine Nursery land onto the Quick Property from that which, but for the Alpine Nursery development, would have flowed onto the Quick Property, due to the particular alterations in the use or conformation of the land that have been pleaded or otherwise. (b) In light of my finding in (i) this question does not arise. However, had it arisen, I would not have been satisfied that the plaintiffs have established that water flowing from the Alpine Nursery onto the Quick Property since May 2004 has contained levels of nutrients or chemicals which would amount to water pollution for the purposes of the definition contained in the relevant legislation. (c) Again, in light of my finding in (i), this issue does not arise. However, had it arisen, I would have accepted the findings of the respective experts to the effect that the defendants' actions have had the effect of reducing the amount of subsurface groundwater percolating through into the Quick Property but I would not have been satisfied that this was the cause of the failure of the bore on the Quick Property (and in any event I would have followed Borough of Bradford v Pickles [1895] AC 587 as applied in Xuereb v Viola (1990) Aust Torts Reports 81-012 (from 39) and held that there was no cause of action for nuisance arising out of the deprivation of groundwater that would otherwise percolate through underground undefined channels). (d) Again, in light of my finding in (i), this issue does not arise. However, had it arisen, I would not have been satisfied that the evidence established a claim in nuisance based on air pollution, noise or other inconvenience to Mr and Mrs Quick arising from the operation of the Alpine Nursery. (iii) While I consider that, to the extent that the reason for any increase in the velocity or flow of water to the Quick Property in intermediate or extreme rainfall events could be said to be (and this has not in my view been established) the construction of a ridge or levy bank along the eastern side of the Alpine property land (as opposed to the installation of the irrigation and drainage system on the land), this would not have been the result of the natural use of the Alpine Nursery land (for the purposes of a defence in a claim for nuisance), that alteration to the conformation of the Alpine Nursery property has not been pleaded as a cause of the alleged water flow interference. To the extent that the reason for any increase in the velocity/flow of water or water flow interference is the installation of the irrigation and drainage or water retention system which diverts rainfall around the dam to the Ellis Road culvert (or the existence of black plastic sheeting and gravel roads on the downhill or northern slope of the property, which reduces the natural absorption of rainwater into the soil), I find that this is a result of the natural use of the Alpine Nursery land. (iv) I am not satisfied that it is likely that water in the future will be caused to flow from the Alpine Nursery land to the Quick Property in a materially greater amount than it naturally would but for the use and altered conformation of the Alpine Nursery land. Similarly, I am not satisfied that it has been established that water is likely to flow through to the Quick Property (from the property to the east of the Alpine Nursery or from an overflow of the No 1 water retention dam) in intermediate or extreme rainfall events in future in a more concentrated form or with greater velocity than would otherwise be the case (having regard to the irrigation and water management plan that is in place and the fact that any dam overflow will occur in circumstances where the run-off from the property and other sources will be extremely high) so as to give rise to an actionable nuisance and thus to warrant a finding of apprehended nuisance. (v) This question does not arise, given my finding in (i) above. However, even if the claim in negligence could have been maintained, I am not satisfied that there has been a breach of any duty of care owed by the defendants to Mr and Mrs Quick or that Mr and Mrs Quick have established that they have suffered loss or damage as a result of the actions of the defendants which are relied upon as constituting the breaches of duty of which complaint is made. (vi) In light of the above findings, this issue does not arise and the appropriate order is to dismiss the Amended Statement of Claim with costs. Had I been satisfied that Mr and Mrs Quick had established their claim in respect of past nuisance by reference to one or more occasions when their fences were knocked over, then I would have ordered nominal damages (since there is no evidence as to the cost to rectify the fence). In the absence of evidence as to the diminution of value of the property by reference to the waterlogged paddock, any damages for loss of enjoyment of the paddock would be nominal. Had I been satisfied that Mr and Mrs Quick had established their claim in respect of apprehended future nuisance, by reference to the likely 'overtopping' in future of the dam, then I consider that the appropriate relief would have been to direct an enquiry as to the appropriate remedial measures to minimise the risk of overtopping of the water retention dam on the northern slope of the property. Background facts Topography of the area 13 Critical to an understanding of this dispute is the topography of the area in which the respective properties are located. In this regard it was of considerable assistance to me to have undertaken (on the parties' joint application) a view of the properties on the first afternoon of the hearing. The following description of the area is drawn in part from my observations during the view. Of use also, in appreciating the location and main features of the subject properties, I attach a précis map (not to scale) which has been prepared simply as an aid to the reader's understanding of the general topography but which is not intended as any definitive representation of the area. 14 The area of land in question forms what Mr Kerr described as a bowl, the lowest point of which is at the south-western corner of the Quick Property - a paddock fenced off from the rest of the Quick Property and referred to variously as the southern paddock, south-western paddock, cattle dam paddock or cattle paddock (and, less flatteringly but with commendable accuracy as I experienced on the view, as a bog or boggy marsh). 15 The Quick Property is on the northern side of Ellis Road, opposite the western end of the Alpine Nursery. The entrance to the Quick Property is not far from and to the west of the driveway entrance to the Alpine Nursery. 16 On the western boundary of the Quick Property is what was referred to as a 'paper road' or 'unmade' road, that being a vegetation corridor which forms part of the natural watercourse for water flowing from the higher ground on the southern side of Ellis Road, through the Ellis Road culvert, through the southern (cattle) paddock, and then into the paper road and down to Marom Creek. That area of the paper road (described, perhaps with some degree of exaggeration, by Mr Kerr as a jungle) adjacent to the Quick Property was, as I observed on the view, relatively densely vegetated. On the opposite side of Ellis Road (on the western boundary of the Alpine Nursery) is a similar 'paper road' (although the state of vegetation there was markedly different from that on the Quicks' side of Ellis Road, the grass appearing to have been mown and there being little if any trees or undergrowth in that vegetation corridor). 17 Immediately in front of the southern paddock on the Quick Property is a culvert that runs under Ellis Road and carries water from the Alpine Nursery or southern side of the road to the Quick Property. The Ellis Road culvert discharges water directly at the lowest point of the southern paddock. On the afternoon of the view, which took place in dry weather, the concrete apron in front of this culvert was dry. (Mr Quick's evidence was that there was a constant trickle of water even in dry weather. However, as I understand it this was said to relate to the flow of water first thing in the morning.) Further up Ellis Road to the west is another culvert running under the road. (On the afternoon of the view, the entrance on the Alpine Nursery side of this culvert appeared dry and was blocked with leaves and grass.) Along Ellis Road to the east, just beyond the driveway to the Alpine Nursery, is yet another culvert which drains water this time from the northern (Quick) side of the road to the Alpine Nursery side of the road (from which point water runs either down the road or along the Ellis Road frontage of the nursery into the Ellis Road culvert which opens onto the Quick Property). The properties to either side of the Quick Property are on higher ground than the southern (or cattle) paddock, though the paper road adjacent to the southern paddock appeared to be roughly the same level as the paddock. 18 The area most affected by any water run-off from the northern side of the Alpine Nursery (or, for that matter, from other properties to the south of the Quick Property) is therefore the southern or cattle paddock – the south-western corner of the Quick Property. 19 The Alpine Nursery land is 16.43ha in size and basically rectangular in shape. Its northern frontage (approximately 205m) is on Ellis Road roughly opposite the Quick Property. The Alpine Nursery land boundary at its southern point runs along Youngman's Creek. The land is approximately 800m deep. As it faces the Quick Property, the land occupies a relatively steep downhill slope. At the highest point of the property (just above where an office and car park are located) there are now potting and treatment sheds as well as a propagation shed. Behind the potting sheds (and towards the back of the property) there is a small evaporation pond. Beyond this area there are two water retention ponds or dams (known as dams 2 and 3), which were built after the initial phase of the development of the land. 20 The Alpine Nursery land comprises two separate environmental planning zones - from the propagation sheds down towards the Quick Property, the land is largely zoned 7(c) as an environmental protection catchment area, the purpose of which is to prevent development which would adversely affect the quantity or quality of the urban water supply. Towards the back of the Alpine Nursery land, where the No's 2 and 3 water retention dams are located, the area which leads to Youngman's Creek is zoned 1(a) as a general agricultural zone. 21 The Alpine Nursery land also straddles two catchment areas: the Marom Creek catchment area which covers much of the northern slope of the property (water falling on which, if not otherwise absorbed by the soil, would, prior to the development of the Alpine Nursery, generally run down the front slope of the property down to the Ellis Road culvert and pass under the road to the Quick Property, where it would fill the cattle dam and then pass in an 'S' shaped curve through the southern paddock and out into the paper road before reaching Marom Creek); and the Youngman's Creek catchment area at the top of the property (water falling on which runs from the back of the Alpine Nursery land to Youngman's Creek). 22 Since the Alpine Nursery development, the course of the water falling onto the northern slope of the property has been altered. Broadly speaking, there is a distinction between the fate of water falling onto the nursery garden or production beds on the front slope of the nursery (which, to the extent not absorbed by the soil in the pots sitting on those garden beds, drains into agricultural pipes which lead down to the No 1 water retention dam at the northwestern corner of the property and is recycled in due course for irrigation) and the water falling onto the areas outside the pods (such as the internal gravel covered roads) (which flows down internal roadways and through drains under those roadways through a 'biofilter riparian zone' to a grass swale or culvert running parallel to Ellis Road and then to the Ellis Road culvert and across to the Quick Property). (Mr and Mrs Quick contend that the fact that the irrigation system diverts water down the internal roads means that it arrives at the bottom culvert more quickly than it otherwise would – nowhere, however, was there expert evidence as to the rate of the flow onto the Quick Property of water arriving at the Ellis Road culvert or the impact if there were any increase in the velocity of the water.) 23 Water from the properties to the east of the Alpine Nursery flows down the eastern side of the metaphorical 'bowl' and, through a green 'silt curtain' erected by the defendants (and designed to impede the passage of silt, not water), along the grass swale running parallel to Ellis Road and thence to the Ellis Road culvert and the Quick Property. Prior to the development, and in particular prior to the creation in around May 2006 of a ridge or levy bank along the eastern boundary of the Alpine Nursery land, water flowing down to Ellis Road from the property on the eastern side of the Alpine property (the Sultana property) would not have been channelled in such a fashion but, according to the irrigation and water management consultant who had responsibility in relation to the design of the irrigation and water drainage system at the Alpine Nursery (Mr Christopher Rolfe), would have flowed down the existing driveway to the Alpine Nursery and thus arrived at the grass swale in similar fashion. Indeed, Mr Rolfe suggested that the water from the eastern property or properties would have arrived at the culvert more quickly than it now does (as he says it is now slowed to some extent by the grassed area it flows down – T152.39). (This gainsays the suggestion by the plaintiffs' hydrological expert, Mr Dey, that the water would previously have flowed across (not down) the road and across the northern slope of the Alpine Nursery land thus permitting greater absorption on the way.) View 24 As noted, on the afternoon of the first day of the hearing, a view was conducted of the Alpine Nursery land and the southern paddock on the Quick Property. The weather was dry (a point of relevance when inspecting the Ellis Road culvert). The view commenced at the top of the Alpine Nursery property where I was shown the southern boundary and the area leading to Youngman's Creek; the two water retention dams (Nos 2 and 3), each of which has a spillway for overflow (that overflow going down to Youngman's Creek); a small evaporation pond (used to assess the level of irrigation needed for the nursery on a daily basis – which depends on the amount of evaporation); the treatment shed and water testing facility – where I was shown the testing equipment; and the potting and propagation sheds (the latter enclosed and kept in a humidified condition). 25 From roughly the level of the car park office facility and a shaded area of plants, the slope ran downwards towards Ellis Road. I was shown the production area or garden beds (referred to variously as pods or pads) which are lined with black plastic membrane or sheeting. On most (but not all) of those beds there were closely spaced rows of plastic pots in which were planted trees or shrubs of different heights or maturity. Some of the garden beds were empty (though also covered with black plastic), presumably awaiting the placement of pots on them. The garden beds are separated by internal gravel roads. 26 At one corner of each of these garden beds was a fixed sprinkler structure with a rotating sprinkler head to which was fixed a red plastic shield (the purpose of which is obviously to direct the angle of spray from the sprinklers towards the garden beds and thus to prevent 360 degree rotation). (On some of the lower parts of the nursery there was a track sprinkler system but this was not the focus of much discussion during the view.) I was informed that other than some drips, the water from the fixed (red shield equipped) sprinklers does not flow down the sprinkler or on the outside of the red plastic shield. 27 Some emphasis was placed by Mr Dey during the inspection on the possibility (or likelihood) of water from the sprinklers falling outside the garden beds and on the gravel walkways. Mr Dey raised questions as to the effectiveness of the red plastic shields and, at one instance, demonstrated with physical gestures the way that the angle of the flow from the sprinkler heads would spread out over the gravel walkways depending on how the sprinklers were angled. (In windy conditions, it must also be possible as a matter of commons sense that irrigation from the sprinklers would be sprayed by the force of the wind outside the garden beds.) 28 The significance of this is that water falling on the internal roadways or walkways (as explained above) ends up in the Ellis Road culvert whereas water falling on the production beds, if not absorbed by the soil in the pots, ends up in the No 1water retention dam. (The other point to note is that Mr Dey had apparently seen fit express opinions as to the irrigation system, and the extent of coverage of the black plastic for that matter, without a complete understanding at that stage of the way the sprinkler system operated or any view of the nursery other than that obtained from outside the grounds, a matter on which Mr Kerr relies as going to Mr Dey's credit, a matter to which I will return in due course.) 29 The colour of the gravel on the pods or garden beds was different from that on the internal walkways, though it does not seem as if there is any significance to this. I observed that there was moist soil underneath some of the gravel in the walkways. 30 In each of the garden beds there is a drainage pit or grate through which water passes and from which water is piped through to the No 1 water retention dam. 31 In the middle of some of the internal walkways intersections, there are also drainage pits from which water falling on the gravel roads is drained down to the grass swale or culvert parallel to Ellis Road and thence to the Ellis Road culvert. 32 After inspection of the No 1 water retention dam (at the corner of which is a small pumphouse from which water can be pumped between the various dams and the testing facility), in the middle of which there is an aerator, and of the overflow point or spillway at the north eastern corner of the dam, I was shown the outlet of the drain from the spillway (where the soil was damp) which leads into the riparian bio-filter area. There is a grass swale running parallel to Ellis Road which leads into that area. 33 I was taken to the eastern boundary of the Alpine Nursery land at the Ellis Road end and shown the silt curtain between the Alpine Nursery land and the Sultana property. The silt curtain was made of dark green material and I observed the build up of reddish silt on the Sultana property side of the curtain. I also observed the eastern ridge or levy bank. Mr Dey made some observations as to the temporary nature or impermanence of the silt curtain and as to its inability to impede the flow of water down the swale (though, as I understand it, the purpose of the silt curtain is not to impede water flow but to impede the flow of silt – and in the absence of this silt curtain presumably a proportion of the silt caught by the curtain would end up on the Quick Property). (In response to an objection by Mr Kerr as to evidence of this kind being given by Mr Dey during the view I noted that I would listen to what was said by those at the view as being in the nature of submission.) 34 Mr Kerr pointed out the culvert on the northern side of Ellis Road to the east of the Alpine Nursery which I observed appeared to be at a higher level than the land on the Alpine Nursery side of Ellis Road. Water from that culvert also drains down to the Ellis Road culvert opposite the Quick Property and through that culvert to the Quick Property. After inspection of the riparian bio-filter (which in lay terms appeared to be an area densely populated with medium sized shrubbery and thick grass but which was not boggy underfoot) and the entrance to the Ellis Road culvert opposite the Quick Property, there was an inspection further to the west along Ellis Road of another culvert. 35 From Ellis Road, I observed the neighbouring property to the west of the Quick Property and the paper road adjacent to the southern paddock as well as the fence at the corner of the Quick Property (which appeared to be pushed back to a rakish angle). I was shown the point of discharge from the Ellis Road culvert at the southern paddock. The concrete apron of the culvert was dry, although there was water in the southern paddock itself. 36 It is no understatement to say that the southern paddock was largely waterlogged. Near the Ellis Road culvert I observed that some of the water had an oily sheen and that there was some gravel in the water. In other areas there were clumps of what seemed to be weeds. The so-called cattle dam was filled with water. I did not attempt to estimate the depth of the water in the southern paddock other than to note that there were places in which it was at least to mid-calf level and the ground did not appear to be level underfoot and that the water in places was in small ponds between the clumps of grass and weeds. The soil was muddy and reddish in colour. The boundary fence was clogged with weeds and debris. The water in the southern paddock appeared to be stagnant. It was certainly not obvious that there was any running flow of water out of the paddock. 37 The land on the Quick Property immediately adjacent to the southern paddock was damp but appeared to be well maintained. I was shown the location of the failed bore in the front yard of the Quick Property. I also observed a number of signs at the entrance to the Quick Property, the thrust of which appeared to be disclaiming responsibility on the part of Mr and Mrs Quick for the quality of the run-off water to Marom Creek with references to polluted water. 38 I should also note that during the course of the view I was informed that the most recent occasion on which water had flowed across Ellis Road (ie not just through the culvert) onto the Quick Property had been during early June around the time of the Lennox Head floods. 39 (I should also note, so that there is no confusion, that although referred to by Mr Quick as the 'cattle' paddock, and the dam on it as the "cattle dam', the southern paddock does not seem to have been used by Mr and Mrs Quick for cattle agistment purposes. Rather, it seems that it was so named because a neighbouring owner's cattle had (for a time) been able to drink water from a hole or dam that had been excavated in that corner of the Quick Property by the previous owner, Mr Robert English. (Mr English in fact referred to this as a geese dam because he said he had intended to have geese in that paddock.) 40 Mr English gave some evidence by audio-visual link as to his observations of the condition of the southern paddock during the period he owned the land. In particular, he gave evidence that the paddock had occasionally flooded and that, when it did, it took approximately three days (5 days if there was continuous heavy rain or, at its heaviest, up to 10 days) to clear. He also said that when he owned the land he took steps to maintain the southern paddock (slashing the buffalo grass around the cattle dam) and the paper road (slashing and burning lantana and roughly clearing the vegetation). Mr English said that there were no weeds in the paddock at that time, just the buffalo grass. (Mr Dey seems to attribute this to the presence of nutrients in the water allowing other species to grow but it is not clear on what he bases this other than his stated experience in flood areas.) 41 Mr English, having been shown certain photographs, was of the opinion that there was more water in the post-Alpine rainfall events than in the 12 years that he had owned the property. (Mr Kerr in submissions pointed to the similarity in certain of the particular flood photographs between the position pre-Alpine and post-Alpine, though Mr Philips noted that the one pre-Alpine flood photograph to which Mr Kerr had directed my attention was the only occasion on which Mr English said that the paddock had flooded in the twelve years that he had owned the property.) Acquisition of respective properties 42 Mr and Mrs Quick purchased their property in December 2001. Mr Quick conceded that when he purchased the land it was a time of drought – T 70.17. Neither Mr nor Mrs Quick was a farmer by occupation. Mr and Mrs Quick acquired the land after they retired from teaching. Mr Quick had worked (many years before) part-time on his father's farm. The relevance of Mr Quick's experience as a farmer (about which he was cross-examined) seems marginal, at best. Its only potential relevance, as I see it, might lie in the context of the suggestion by the defendants (that emerged during the course of the concurrent expert evidence) that the present condition of the southern paddock can be attributed to a failure by Mr Quick properly to maintain his land or to do what Mr English had done and to clear the paper road of vegetation (though whether or not Mr Quick was conscious of proper farming techniques at the time seems to me to be of marginal relevance, if any, when considering the issue as to the cause of his waterlogged paddock). 43 The Alpine Nursery land was initially part of a larger property owned by the Sultana family on which a potato farm had been cultivated and irrigated by water from Youngman's Creek. (I interpose to note that, if so, then the pre-Alpine development run-off from the land would have included, as it does post-Alpine, some water from a source additional to the catchment area per se.) The evidence of Mr Rolfe was that when the potato farm was under cultivation there were a series of 'runs' going downwards to Ellis Road along which rainwater would run. Up beyond the Alpine Nursery in the area around Youngman's Creek there is a macadamia plantation, a cattle farm and another wholesale nursery (which indicates the type of natural land use common in the area). 44 In June 2004, Mr and Mrs Knox acquired the Alpine Nursery land. However, their involvement in the development of the property commenced some months before then. There was evidence as to the investigations made by Mr and Mrs Knox prior to their purchase of the land as to the conditions applicable for the operation of a commercial nursery on the land (and Mr Kerr, in his submissions, emphasised the extent to which, prior to purchase, Mr and Mrs Knox had contacted many of the relevant governmental state and local authorities and the significant amount of time care and attention given to the development of the Alpine Nursery land). 45 Objection was raised prior to the hearing to the evidence sought to be adduced for the defendants as to advice provided to them by experts in relation to the operation of the nursery. This evidence was pressed by junior Counsel for the defendants, Mr Robertson, on the basis that the defence of reasonable and natural user of the land meant that evidence of best practice user of the nursery was of relevance (such that if the irrigation and drainage management plan was in the ordinary and proper manner without negligence or wilfulness this would be relevant according to Bayliss v Lea (1961) 62 SR (NSW) 521; [1961] NSWR 1002; (1961) 79 WN (NSW) 218) and further on the basis that as the plaintiffs were in effect seeking quia timet relief they needed to show that it was likely that the defendants would commit further acts of nuisance in the future and that the irrigation and drainage management plan was relevant to that issue. (Objection was also taken to evidence as to the attitude and behaviour of the plaintiffs towards nursery staff and visitors to the nursery, which was pressed by Mr Robertson on the basis that, insofar as nuisance related to neighbourhood interactions and involved a balancing exercise between the parties' rights in relation to use of the land, the alleged ultra-sensitivity of Mr and Mrs Quick would be of some relevance.) I accepted Mr Robertson's submissions and admitted the evidence on the basis or bases so indicated. 46 By letter dated 31 December 2003, a development application was submitted in relation to the Alpine Nursery land. That development application submitted by Alpine Nurseries to the local Council was for the development of a 'water storage facility' (to which I refer as the No 1 water retention dam but which is also variously referred to in the evidence as a water retention 'pond') on the northern slope of the property. 47 The development application referred to the water storage facility as being the first stage of development on the land. A brief statement of environmental effects (prepared from information provided by Mr Rolfe if not indeed also prepared by him) accompanied that development application. A general description was given of the nature of the development. It indicated that production beds were to be sealed off and that run-off was to be directed into the retention storage facility by the drainage system. Run-off other than production beds was to be allowed to flow down the natural waterways. The development application also referred to grassed waterways to be constructed to carry water under Ellis Road by the existing culvert. 48 The development application distinguished between the various ways in which water falling on the property was to be treated. Consistently with the description I have given above, water falling on the production beds on the northern slope facing Ellis Road (which are lined with black plastic sheeting and on which there are many individual plants or shrubs in pots), and which is not absorbed in the pots, was to be piped to the No 1 water retention dam and retained there (in due course to be piped as necessary to irrigate the plants and treated); water falling outside the production beds (on the internal roads) was to be allowed to run down the roads and/or piped around the water retention dam and then to run off the property in three narrow channels into the grass swale, through the riparian bio-filter, into the Ellis Road culvert and eventually onto the Quick Property. 49 Mr Rolfe was adamant that the development application had been prepared in accordance with best industry practice and that account had been taken of the potential impact on downstream neighbours. His explanation as to the basis on which he formed the view that there was no adverse impact on the neighbours was in my view logical and I saw no reason not to accept it. 50 Consent to the first development application was given on 29 March 2004. Reliance is placed by Mr and Mrs Quick, particularly in the context of their claim in negligence, on the alleged non-compliance by the defendants with conditions of the consent given for the development. In submissions, Mr Philips referred to condition 1.5 (namely that discharge of water from the dam was to be undertaken in a manner that would not adversely concentrate the water into the downstream drainage system – whereas Mr and Mrs Quick say that by the nature of the design of the property the water does concentrate into the downstream drainage system in times of heavy rainfall because they contend that there has not been sufficient pervious or riparian land between the dam and the downtown drainage system); condition 1.7 (namely that the dam base be 1m above the current water table and concealed with impermeable liner – although it is not clear how it is contended that this was breached); and condition 1.8 (namely that all water other than water from the nursery beds be diverted around the water storage facility – again, it is not clear how it is said that this condition has been breached; indeed the diversion of water from around the nursery beds seems to be one of the matters on which Mr Dey relies for the conclusion that there has been an increase in the water flow to the Quick Property, on the basis that the drainage of water along internal roadways has caused water to flow more rapidly off the land). 51 Reliance was also placed on the fact that the dam is of less capacity than that specified in the application. (In that regard, there is correspondence in June 2006 with the Council in which the reason for the alteration of the specification of the dam was enunciated – it was said to have been made slightly shallower and wider compared to the original specification (due to the need to saitisy condition 1.7) – see p228ff, Exhibit D). That letter asserted that the revised size of the dam had been notified to Council in May 2005. 52 No notice was given by Mr and Mrs Knox, or their company, to Mr and Mrs Quick of the development application or of their intention to develop the property as a commercial nursery. Mr Knox gave evidence, which I accept, that he thought the Council would have given notice of the development application to Mr and Mrs Quick (presumably as owners of a neighbouring property) – T 109. For whatever reason, it appears that the Council did not do so. Mr and Mrs Quick say that the first they knew of the proposed development was when excavation works began in May 2004 for what was to become water retention dam 1. (This is consistent with the recollection of Mr Knox that when he first met with Mr and Mrs Quick they seemed mainly to be unhappy that Council had not advised them in advance of the development application – T 111.8). 53 Mr Knox and the manager of the Alpine Nursery (Mr Bruce Wilson) visited Mr and Mrs Quick at their home in May 2004. (In the witness box Mr Knox said that he had been reminded by his wife of another meeting with Mr and Mrs Quick around that time but confirmed that his recollection was that the first meeting was that which took place at the Quick Property.) Mr Quick deposed to having been assured by Mr Knox at this meeting in May 2004 that the dam would not collapse causing a dangerous torrent of water in the direction of the Quicks' property (as opposed to overflow on some occasions). Mr Knox denied saying "the dam would never overflow" although did depose to saying that the dam would not collapse (at paragraphs 46 and 93 of his affidavit sworn 31 March 2010). It seems to me unlikely, given the considered and careful manner in which Mr Knox gave his evidence (and his ready acceptance of propositions that might have been thought to harm his case, such as the likelihood of future dam overflows), that Mr Knox would have given an assurance inconsistent with the development application consent which itself required that there be provision for a spillway to permit overflow from the dam in times of heavy rainfall (see condition 1.4 of Notice of Determination of a Development Application 2004/649, at p 96CB). 54 Mr Knox agreed that by the time he met with Mr and Mrs Quick, construction had commenced and the company was committed to the nursery – T 108.34, and that from a commercial perspective there was no alternative other than to proceed with construction of the dam in accordance with the approved plan – T 110.28, and that he had not taken any steps to change the master plan or to reduce the impact on the Quick Property after he had met with them. However, Mr Knox also said that they had not asked him to do so - T 111.25. 55 It is by no means clear to me that Mr Knox (or the other defendants) appreciated or should have appreciated that there might be an adverse impact on the Quick Property by reason of the construction of the water storage facility in accordance with the development application. Mr Rolfe's evidence, which I accept, was that the position of neighbouring properties had been taken into account and that it was his view that the water management plan would have the effect of minimising any impact on downstream neighbours such as Mr and Mrs Quick. Accordingly, insofar as the above evidence is relied upon to suggest a wilful disregard or recklessness by the defendants at that stage in relation to the effect of the development on Mr and Mrs Quick's use and enjoyment of their property, I would not accept that to be the case. 56 (In that regard, I note that in closing submissions Mr Philips suggested that recklessness as to interference with the plaintiffs' rights could be inferred from three things – the fact that the dam was of lesser capacity than specified in the application for development consent; the recognition in the management plan for retention storage at the No 1 water retention dam that the capacity of the dam, as built, was of less capacity than the average likely rainfall and was thus bound to fail; and that the application in relation to the levy bank on the eastern boundary was said to have been made to prefer the defendants' own commercial interests so as to stop silt from the adjoining property from travelling across the nursery land. It seems to me that it is only the first two matters that might go to reckless disregard of the plaintiffs' interests and that they must be taken into account along with the fact that the property was in a flood prone area and the views (right or wrong) of the defendants' consultants as to the minimisation of harm to the plaintiffs, to which I refer later.) 57 Construction works in relation to the No 1 water retention dam took place from around May 2004 onwards. Mr Quick gave evidence that a row of camphor laurel trees running along Ellis Road on the northern roadside of the Alpine Nursery property were removed (though there does not seem to be any suggestion that this was a cause of the alleged increased water flow onto the Quick property and, subsequently, other trees were planted along the roadside). The No 1 water retention dam is not now visible from the Quick Property. 58 The No 1 water retention dam has a 45° slope and an overflow point or spillway at the north eastern end of the dam close to the Ellis Road culvert. I observed the discharge outlet for the dam and note that water would flow from the spillway out into the so-called riparian zone and converge with water flowing down the grass swale to the Ellis Road culvert. (The riparian zone was relatively densely vegetated when I observed it on the view.) 59 Although the dam was proposed in the development application to be of a particular capacity (8.6 megalitres), the dam as built has a capacity only of around 6.3 megalitres. This is because during the construction of the dam it was found that the subsurface (or perched) water table was closer to the ground than had been thought. The development consent conditions required that the dam base be 1m above the current water table and Mr Rolfe explained that there cannot be interference with the perched water table (which he described as an underground lake the size of which varies during the different weather conditions created by reason of the effect of the construction of Ellis Road which obstructed the natural watercourse across that area – T154). 60 Therefore the dam could not be excavated to the depth originally intended and is of less capacity for that reason. However, the dam was lined, as required under the development consent conditions, and the evidence is that there is kept a minimum of about two and a half metres head space in the dam to allow for unexpected rainfall events. Mr Wilson also says that there is a capacity to pump close to a megalitre of water out of the dam in a 24 hour period (T 171) and Mr Dey seemed to accept that the pumping capacity would be effective to prevent overflow provided there was less than 75mm rainfall in any 24 hour period (though that would presumably depend on the time when the pumping commenced – if measures were taken to start pumping water from the dam when flood or heavy rain warnings were received then presumably other than in flash floods the effectiveness of this measure would be increased). In any event, there is no basis on which to find that the dam construction was in breach of the development consent conditions simply because it was shallower and wider than specified in the application. 61 Reliance is placed on the reduced capacity of the dam for the proposition that it is inevitable that the dam will overflow during the course of the year (the rainfall records showing that there are on average one or two rainfall events greater than a 6.3 megalitre storage capacity) and on Mr Rolfe's concession that the dam does not have the storage capacity to hold all of the rainfall that is likely to fall on the property (T 148). 62 In around August 2004, construction of the No 1 water retention dam was completed. (Any problems of water flow before then cannot therefore have been due to the retention of surface water in the dam.) 63 Mr Quick's evidence is that prior to the Alpine Nursery development water only ran through the Ellis Road culvert after heavy rain. (He also gave evidence that on the Alpine Nursery land there was a small spring from which there was clear water and that it silted up only after times of heavy rain.) Mr Quick says that in the period from 2000 to 2004 there were two or three heavy rainfall events in which the water gushed through the culverts and that the soil was wet for a week or so and then drained off the property after a period of about a week and he could then mow his property. (Mr Quick in cross examination conceded that he had only attempted to mow his property once this year but said when he attempted to do so his ride-on mower became bogged. There is nothing to suggest that a hand held slasher could not be used in those circumstances but Mr Quick's evidence was that he was not in a condition to use one.) 64 I interpose to note that, on Mr Quick's affidavit evidence, from May 2004, the cattle paddock on his property was "constantly wet" to such an extent that it was impossible properly to mow and maintain that area of his land. If so, then this means that as soon as the excavation works commenced, and some 3 or 4 months before the dam was completed (and some 6 months or more before the earthworks occurred on the eastern ridge of the Alpine Nursery land), his property was already 'constantly wet'. Therefore, either Mr Quick has exaggerated his evidence in this regard or, if not, the problem of constant wetness of the southern paddock is one which arose independently of and before completion of the earthworks on the eastern side of the driveway on the property (now blamed by Mr Dey for concentrating the flow of water on the property) and before the retention of water in the No 1 water retention dam (although of course the later alterations to the conformation of the land might have exacerbated that problem). 65 Mr Quick gives evidence that on 9 November 2004 the fence on the southern boundary of the Quick Property was knocked over following heavy rainfall (Mr Quick notes the rainfall on that occasion as being 62mm). Mr Quick says that on at least 12 occasions since May 2004 the cattle paddock has flooded and that on a number of occasions the fence on the boundary of his property was knocked over. When cross-examined in relation to the flooding which had occurred, Mr Wilson did not deny that the No 1 water retention dam had 'overtopped' on around a dozen occasions over the period. Nor is it denied that there was damage occasioned to the boundary fences on the Quick Property over the relevant period. (In cross-examination Mr Knox agreed that at one stage an offer had been made by the defendants to meet the cost of repair of the fence. That offer was apparently coupled with a condition that Mr Quick withdraw his threat of legal action and was not accepted by Mr Quick. Mr Knox agreed that no further such offer had been made.) 66 By December 2004 or early 2005, some of the nursery operations on the Alpine Nursery land had commenced. Mr Rolfe gave evidence that commencement of those operations had taken place before the completion of all aspects of the development (for cashflow purposes) and that this is what had led, at least indirectly, to the blue-green algae outbreak in May 2005. 67 Mr Quick gave evidence that in January 2005, there was further flooding of the southern or cattle paddock. (In general, there was no contest by the defendants as to the evidence given by Mr Quick in relation to the occasions on which the paddock had flooded, and I accept his evidence that it did flood on those occasions. There was, however, a contest as to whether the flooding was due to the development of the Alpine Nursery land or whether it was simply a natural consequence of the topography of the area itself.) 68 On 11 February 2005, the Council wrote to the defendants requesting an explanation as to why consent had not been obtained before the undertaking of earthworks in the 7(c) water catchment zone. That letter referred to those as being for an amenities office and a small shed. Reliance is placed by Mr and Mrs Quick on this letter (p 149 Vol 6 Ex D) as indicating non-compliance with the Council's requirements. The defendants' response, which is at p152ff in the same volume, explained the circumstances in which flooding had occurred in January 2005, denied non-compliance in the main with the Council's requirements byt acknowledged a need to be more conscious of the need to maintain adequate air space in the dam to allow for any future significant rain events and confirmed that instructions had been given for this to occur at all times in the future. 69 In March 2005, four cows owned by Mr and Mrs Quick's neighbours died. There is no evidence as to the cause of death. It seems that Mr and Mrs Quick infer that this was in some way caused by the cattle drinking polluted water from the dam and that this polluted water came from the Alpine Nursery (since otherwise its relevance to anything in the proceedings would be difficult to imagine). (Given that there was a similar algae outbreak two months later in the No 1 water retention dam, it is certainly conceivable that water containing such algae could have flowed to the Quick Property if the dam had overflowed in that period. The cattle might, however, have died from any number of contaminants from a variety of sources or otherwise.) I cannot see how any relevant inference could be drawn from the death of the cattle (there having been no testing of the water in the dam and no admissible evidence as to the cause of death of the cattle). In fairness to Counsel for Mr and Mrs Quick (Mr Philips), I should note that I was not asked to draw any such inference and I do not do so. (In any event, as discussed later, I do not consider that any claim in nuisance based on the water quality as it arrived on the Quick Property can be maintained in light of the fact that there is no pleading to that effect.) 70 On 24 March 2005, Mr Quick sank a bore on his property. It was apparently operational when first installed but then failed. Mr Quick blames the fact that it does not now operate on the activities of the defendants on the Alpine Nursery land. This was an issue considered by the two experts and I consider it later. Again, however, I do not consider that any claim in nuisance based on the reduction of subsurface water percolating through the Quick Property can be maintained in light of the fact that there is no pleading of nuisance in that regard. 71 In May 2005 there was an outbreak of blue/green algae in the area. Tests showed the presence of such algae in both the cattle dam and the No. 1 water retention dam. A notice was issued on 17 May 2005 under s 96 of the Protection of the Environment Operations Act. Mr Rolfe explained the circumstances in which that algae outbreak occurred – he says it was due to the lack of available power to operate an aerator in the dam (that lack of power not having been anticipated at the time the nursery operations commenced). Mr Rolfe also explained the manner in which that outbreak was treated by 'environmentally friendly' pesticides. Since then the only evidence of elevated microcystis levels (indicating the presence of blue-green algae) has been in connection with dams 2 and 3 (although there was some suggestion of toxicity in April this year. There is, however, no suggestion of any further outbreak of blue-green algae in dam 1 and there was evidence of a more rigorous testing programme at least since 2009 in relation to water quality leaving the Alpine Property and on every occasion after an overflow from the dam, none of which indicated a problem with water quality. 72 It was put to the defendants' witnesses in cross-examination that it was the direction from the Council to take preventative action in relation to the May 2005 algae outbreak that had led to the preparation of the first Irrigation and Drainage Management plan for the retention and storage of water on the nursery. That was not accepted by the defendants. According to Mr Fitzgerald, there was testing carried out prior to the implementation of the water testing regime the subject of the respective management plans but this testing seems to have been confined to the water in the No 1 dam and to be more limited than the programme that has been in place since 2009. (Of course, at the outset there was only the one water dam so it is hardly surprising that the testing regime would not have been as comprehensive at that stage.) 73 The initial Irrigation and Drainage Management Plan referred to the three main criteria that had been considered in developing the Alpine Nursery property: first that the groundwater aquifer was relatively shallow and could possibly be contaminated; secondly, the conditions and licence in relation to use of water and the way it was or could be drained off the property; and thirdly, the shallow excavation of the land was not a reliable water supply so that works had to be undertaken to ensure a reliable water supply to be used as part of the development based on the natural use which could be made of the land. 74 In November 2005, the Council caused alterations to be made to the design of the Ellis Road culvert, extending or adding concrete wings to the points at which water flows in and out of the culvert. That alteration was the subject of complaint from Mr and Mrs Quick, who asserted that it had increased the flow and concentration of water onto their property. At the very least this suggests an alternative or additional cause for the flooding of the Quick Property the subject of the present complaint (which weakens any inference that might otherwise be available as to the cause of the current state of the southern paddock on the Quick Property). 75 In the early part of 2006, earthworks were commenced for the construction of a levy bank along the eastern ridge of the property. This was apparently for the purpose of preventing silt travelling from the eastern property being deposited on the Alpine Nursery land. Objection was taken by the Council to these works (by letter of 21 April 2006 referring to a site inspection in late March 2006). 76 On 19 May 2006, a further development application was lodged by the defendants for earthworks and the construction of new growing areas to the south of the existing development (those being the areas from the top of the property and including the area in which dams 2 and 3 now stand). It was asserted in the pleading that this application acknowledged the detrimental consequences of the existing development on water flow from the property. Certainly, the development application referred in terms to "the issue has been too much water, not the reverse" and acknowledged the abundant water directed to the culvert in front of the Alpine Nursery Property bordering Ellis Road and that it had been a focal point for waters flow in times of heavy rainfall. 77 On July 2006, Council gave its consent to the second development application and the remaining nursery areas were built. 78 The ridge or levy bank on the eastern side of the Alpine Nursery (running alongside the driveway to the property) assumed some significance during the course of argument and is of some relevance for at least two reasons. 79 First, on inspection of the Alpine Nursery property during the view, it was pointed out to me that the soil under the black plastic covering the production beds on the downhill slopes of the Alpine Nursery was not of the same bright red colour as that visible on some of the DVD footage taken by Mr Quick during rainfall events but that the soil which had been trapped by the silt curtain at the bottom of the Sultana property was of that colour. Thus it seems reasonable to infer that any reddish water flowing onto the Quick Property through the Ellis Road culvert (as shown on the DVD footage) must have originated from the Sultana property or other properties to the south east of the Quick Property (not the Alpine Nursery land), which supports Mr Kerr's submission that water from a variety of sources (not just the Alpine Nursery land) converges on the Quick Property during rainfall events. 80 Secondly, the effect of the ridge (as also evident from the DVD footage) seems to be that rainwater from the Sultana property (and perhaps others to the east or south east of the Alpine Nursery land) is channelled down the eastern side of the Alpine Nursery land (and, ultimately, through the 'silt curtain' into the grass swale at the bottom of the Alpine Nursery land running parallel to Ellis Road) rather than flowing either across the production pods on the Alpine Nursery land and then down the slope facing Ellis Road (as Mr Dey said it would) or down the Alpine Nursery driveway (as Mr Rolfe said it would). 81 In either case, the water would end up at the Ellis Road culvert and thus at the entrance to the southern paddock on the Quick Property. The only logical difference would seem to be the speed or concentration of the flow of water as it reached the culvert. There were conflicting views as to what effect that would have. As I understand Mr Dey's reports, he considered that this would have the effect that there was less opportunity for water to be absorbed across the expanse of the Alpine Nursery land (though in a heavy rainfall situation the absorption capacity of the soil would be reduced in any event so that the difference in area over which the water could naturally be absorbed is of less significance). Mr Rolfe, however, gave evidence that before the construction of the levy bank water flowing from the Sultana property ran down the driveway (and would be likely to do so more quickly than down the grassed swale or depression alongside the levy bank). In the absence of evidence as to measurement of the rate or flow, it is difficult to draw any final conclusion from this. Suffice it to say that Mr Dey's own evidence seems to suggest that there is no material adverse impact of the concentration of the water in either heavy or intermediate rainfall conditions and given the evidence of Mr Rolfe as to the pre-Alpine Nursery development flow of water from the eastern properties down the driveway rather than across the slope now covered with the nursery beds, the plaintiffs have not established any materially more concentrated flow by reason of the levy bank. 82 In any event, whatever the effect of the levy bank on the velocity or concentration with which water flowing from the Sultana property and others to the south east of the Quick Property arrives at the Ellis Road culvert, the pleading does not refer to the construction of the levy bank or ridge as part of the change in conformation of the Alpine Nursery land said to have caused the nuisance. Thus even if there has been an increase in the water flow or concentration of water referable to the construction of the levy bank or ridge, it is one about which complaint cannot now be made having regard to my findings below on the pleading points. Further, as Mr Kerr submitted in answer to the concerns I had raised as to the effect of the levy bank, there is no hydrological evidence from which I could reach a conclusion as to the effect on the Quick Property of any increase in the velocity or concentration of that water flow by reason of the construction of the levy bank (or otherwise). 83 Mr Quick gave evidence that in 2008 there were three occasions when the No 1 water retention dam overflowed (4 January, 20 April and 25 July 2008). He also gave evidence as to the occasions in 2009 when there was an overflow. Evidence as to historical rainfall records over the period was produced by Mr and Mrs Quick, including an affidavit by a neighbour (Mr John Ellison), which was not challenged by the defendants. During the hearing I gave leave, over Mr Kerr's objection, to the filing of an affidavit by Mr Quick updating the rainfall records. On average it seems that there have been two to three occasions each year over the past five years in which the rainfall has been of a volume which is categorized as an extreme rainfall event (that description relating to the amount of rain falling during a particular time period and not referring to the frequency or rarity of the rainfall event). 84 On 25 July 2008, there was apparently some concern as to a second blue/green algae outbreak in the area around Youngman's Creek on the southern side of the No 2 water retention dam. A letter was issued to the defendants in September 2008 from the Council (p 130 CB) foreshadowing a direction to take preventative action. Just as in relation to the first Irrigation and Drainage Management Plan, it was suggested by Mr Philips, but not accepted by the defendants, that it was this event that had led to the re-iteration of the plan into what became the 2008 Irrigation and Drainage Management Plan. That management plan was itself the subject of a 'peer-review' from Cardno Lawson Treloar, for the stated purposes of assisting Council to ensure that the water management plan for the nursery would achieve the objectives set out in an updated "Prevention Notice" under the Act. The findings of the peer review were admitted in evidence subject to a s 136 direction limiting the use of some of that evidence. 85 Significantly, in terms of what steps it would be reasonable and practical to expect the defendants to take in order to minimise any nuisance which it might be found they had adopted or continued, Mr Rolfe gave evidence that the requirements that this nursery had been obliged to satisfy in terms of the preparation and review of its water management plans were ones with which no other nursery in Australia, to his knowledge, had had to comply (and the Council itself has acknowledged (see letter dated 4 September 2009 (pp314ff CB) that the defendants had been the subject of a level of scrutiny "that the vast majority of other operations in the rural areas of the shire" had not – in which letter the Council congratulated the nursery for attaining accreditation under the relevant industry accreditation and environmental schemes). 86 For Mr and Mrs Quick it is contended that the latest irrigation and drainage management plan in effect acknowledges that the system will 'fail' in a heavy rainfall event (which I understand to be a reference to the inevitability that the No 1 water retention dam will 'overtop') referring to p 32 of the plan. Thus it is said that no matter how high the dam wall is or how much extra space there is in the dam, it is inevitable that it will overflow on at least one or two occasions a year. (There must be some exaggeration in that proposition – the likelihood of the dam overtopping must surely be a function of the space in the dam at the relevant time and the likely rainfall – if the dam water is kept low enough there could hardly be a suggestion of inevitability of failure.) 87 To be fair, the defendants do not dispute that it is likely that the dam will overtop on one or two occasions a year (Mr Knox seeing this, in effect, as part of the natural order of things, "it is God's will" – T 115.7). What they do dispute is that the overtopping of the dam amounts to a nuisance. 88 Mr and Mrs Quick have been vociferous in their complaints as to the operations at the nursery (both Mr and Mrs Quick, though reluctant in the witness box to do so, ultimately accepting that they had made accusations in relation to a number of persons or bodies as to the nursery operations and had then made various complaints as to the handling of those complaints). Further, the complaints that have been raised as to the nursery operations range from complaints as to the water flowing onto their property, the noise from the nightly irrigation or aerators on the property, the spraying of chemicals on the property, the laying of black plastic and compacted gravel on the property, the erection of the silt curtain on the eastern side of the property and the construction of the earthworks on the eastern ridge (to name what seem to have been the main complaints). The blame has not been confined to the nursery operations. Although again reluctant to concede this, Mr Quick ultimately conceded that he had complained to the Council that its extension of the culvert was responsible for the increased flow and velocity of water. Mr and Mrs Quick appear to have been particularly concerned that they would bear some liability in relation to the quality of the water arriving at Marom Creek (and have erected signs at their property disclaiming in no uncertain terms any such responsibility) though there is no suggestion that they have been met with such a claim or that they would have any responsibility in relation to any polluted water emanating from the Alpine Nursery. (Surprisingly, perhaps, given the emphasis they have placed on the pollution complaints, this was not pleaded as nuisance.) 89 There is no doubt that Mr and Mrs Quick feel very strongly that the Alpine Nursery land should not be operated as a commercial nursery. Mr Quick's references, during cross-examination, to 'normal' farming practice or to clean reliable 'farm water' (T 70) highlight the exception he takes to the size of the operation now being conducted on the Alpine Nursery land and seems to form the basis for the assertion that the use of this land is not a natural use (even though there seems to me little relevant difference in principle between agricultural use and horticultural use). 90 There is also no doubt that the southern or cattle paddock in its current state is unsightly and, for practical purposes, unusable. Mr Kerr pointed, however, to the lack of evidence that the current situation was caused by the defendants and to the fact that the southern paddock has at all relevant times been the recipient of water flowing through the Ellis Road culvert. Criticism was made of Mr and Mrs Quick in relation to the fact that the paper road has not been kept clear of vegetation (and nor has the southern paddock or its boundary fences been kept clear) so as to permit the ready outflow of water from the property along the Marom Creek watercourse. (Mr English's evidence was revealing in this regard, in that he said that when he owned the land there was only buffalo grass around the hole he had excavated in the southern paddock, whereas on inspection during the view it seemed to me that the paddock had clumps of weeds and other undergrowth in patches across the paddock.) 91 In evidence (which I admitted over Mr Kerr's objection) was DVD footage taken by Mr Quick at various times showing water running down the Alpine Nursery slopes, the aerial spraying, irrigation, compacting of the gravel on the internal nursery roads and the like. Prior to the hearing, objection was taken by the defendants to the admission into evidence of the commentary by Mr Quick which was audible on those DVD's (other than insofar as it identified physical sites shown on the DVD's). At that stage I indicated that I did not propose to watch 15 hours' worth of DVD's without being taken to those portions that either party said were relevant and that any audio commentary that was relied upon should be transcribed. In response to that indication, a so-called 'highlights' package was prepared, which comprised a number of DVD's on which edited footage was included, and a transcript was prepared of those portions of the audio commentary on which the plaintiffs sought to rely. Objection was subsequently taken to the transcript proffered by the plaintiffs on the basis that it was not a complete commentary. In fairness to the plaintiffs, it seemed to me that the production of an incomplete transcript was simply a function of my having indicated that only commentary of which there was a transcript could be tendered. In any event, ultimately the plaintiffs did not press for the admission of the commentary into evidence (and it was of limited assistance in viewing the DVD's, as was the digital time imprint which seemed to be incorrect). 92 I watched the highlights package during the courtroom recess at lunchtime on the second day of the hearing, indicating that I would not take into account any audio commentary on the DVD's. There was a further argument during the hearing as to whether additional DVD footage (comprising footage which had been omitted when the initial highlights package was prepared and further footage of the culvert opening the morning after the view) could be admitted into evidence. I admitted that DVD footage, over objection, on the basis that insofar as it was material that had already been provided to the defendants I could see no prejudice to them in so doing and in relation to the footage of 19 July 2010, this was footage that obviously would not have been available at an earlier stage and was relevant in light of some of the observations made on the view (as to the Lennox Heads floods). 93 Also tendered during the course of the hearing was an affidavit annexing updated rainfall records from the second half of May 2010 onwards. I admitted that evidence, again over objection, on the basis that there were already rainfall records in evidence and the defendants had not sought to challenge the veracity of those records nor did it seem to be suggested that there was any inaccuracy in the meterological records so tendered. 94 The defendants maintain (and this is supported by the observations both of Mr Rolfe and of the Council) that they have been subjected to extremely close scrutiny (unequalled in the nursery industry) at all phases of their operations from the Council and that there is no basis for the criticism of their operations. It is submitted by Mr Kerr that Mr and Mrs Quick are unduly sensitive to the nursery operations and that there is no obligation on the part of the defendants to meet the expectations or demands of overly sensitive neighbours. 95 Evidence was given by the defendants as to the preparation of the detailed Irrigration and Drainage Management Plans to which I have referred above; as to the regular (albeit not unfailingly regular) testing of the water on the Alpine Nursery property both by Mr Fitzgerald (on a weekly basis other than when he was in hospital), who says he is also in the process of training someone else in the testing regime, and, on a monthly basis, by an external testing laboratory; and as to the method by which water from the production pods on the front slopes is reticulated by drainage pipes to the No 1 water retention dam and from there to dams 2 and 3 for treatment and recycling. 96 Evidence was also given by Mr Wilson as to the fact that when heavy rainfall is anticipated water is pumped out of the No 1 water retention dam to increase capacity for run-off and to minimise the risk of overtopping, although it is conceded that in some heavy rainfall events it is not possible to pump the water out of that dam fast enough to prevent it from overtopping. Complaints made by the plaintiffs 97 As noted earlier, numerous complaints have been made by Mr and Mrs Quick as to the nursery operations. In the course of submissions by Mr Philips, emphasis was placed on three complaints as to the water flow interference: (a) as to the fact that a large percentage of the northern slope of the property (that being the area falling within the 7(c) catchment zone) is covered with impervious black plastic sheeting (it is said that this concentrates the water in the No 1 water retention dam in an 'unnatural' way); (b) as to the fact that the remainder of the northern slope is covered with compacted gravel (said to be nearly as impervious as the black plastic sheeting), run-off from which runs down the slope and into the grass swale or 'bio-filter riparian zone' and Ellis Road culvert (said by Mr Dey to concentrate the water at the Ellis Road culvert in a manner which would not occur but for the development); and (c) as to the fact that there is almost nightly irrigation (which it is said does not drain entirely into the No 1 water retention dam – as evidenced by the moisture at the outlet of the Ellis Road culvert even in dry weather - and which is blamed for the permanently water-logged state of the southern paddock). 98 While Mr Quick also complains as to the leachate or chemicals in the water on his property (the presence of which he discerns by reference to the colour of the water), a complaint described as ancillary to the main water flow complaint, and has complained as to aerial chemical spraying and the noise of the nursery operations, those matters were not pleaded and (other than some evidence of water samples having been taken of the water in the cattle dam at the time of the blue/green algae outbreak in May 2005) there is no evidence as to the extent or impact of any of those matters. 99 Mr and Mrs Quick seem to have regarded matters such as water testing as the Council's responsibility, which may or may not be the case from a local government perspective, but the result of that is that there is nothing from which I could form a view as to the presence of chemicals in the water on their property or the likelihood that this would occur in future. (Although, as noted earlier, on the view I observed the presence of some gravel in the boggy southern paddock and an oily sheen on some of the water that had ponded in areas on the paddock, both could have come from Ellis Road itself and there was no basis on which I was in a position to form a view solely on that observation as to the quality of the water flowing through or into the Quick Property from the Alpine Nursery land.) 100 Mr and Mrs Quick confirmed that they had not engaged any acoustic consultant or expert to assess noise levels at the property (notwithstanding their complaints as to noise pollution) thus making it impossible for me to form a view on those matters (even had they been properly pleaded). 101 I turn then to the issues for determination. Issues Pleading Issues (i) Can Mr and Mrs Quick maintain their claim in negligence and/or their claim in nuisance in relation to water quality, reduction in subsurface percolation, noise, aerial spraying or other issues not pleaded in paragraphs 24/25 of the pleading? 102 As noted earlier, there are two respects in which it is said that the claims made by Mr and Mrs Quick have not been properly pleaded: first, in relation to the claim in negligence and, secondly, in relation to certain aspects of the claim in nuisance (and/or negligence) not referred to in paragraphs 24 and 25 of the pleading (principally the water pollution allegations and the reduction in groundwater/subsurface percolation allegations but also the noise and aerial spraying issues). 103 I consider these in turn. (a) Negligence – Paragraphs 29 and 30 of Amended Statement of Claim 104 The claim of negligence, as pleaded in paragraph 29 of the Amended Statement of Claim (and without reference, for the moment, to the particulars appended to paragraph 29), could on no stretch of the imagination be seen as compliant with the rules of pleading. It simply states a conclusion of law: Further, or in the alternative, the matters complained of by the Plaintiffs were caused by the negligence of the Defendants. 105 It is not sufficient that a pleading simply express a conclusion drawn from facts which are not stated (Trade Practices Commission v David Jones (Australia) Pty Ltd (1985) 7 FCR 109, at 114 (though in some circumstances to plead a conclusion may be to plead a material fact - Kernel Holdings Pty Ltd v Rothmans of Pall Mall (Australia) Pty Ltd (unreported, French J, Federal Court of Australia, 3 September 1991)). What is required is that there be a clear pleading of the material facts on which the cause of action is founded. There is no such recitation of material facts in paragraph 29. 106 Further, the matters asserted to have been caused by the alleged negligence have not been identified other than that they are matters of which complaint has been made (the 'matters complained of'). The paragraph does not make clear whether those complaints are the ones referred to in the preceding paragraphs of the pleading or elsewhere, whether or not in the pleading. The defendants are entitled to know just what matters are said to have been caused by the alleged negligence. 107 The fact that Mr and Mrs Quick have made numerous complaints in various forums over a period of years in relation to the operation at the nursery compounds the pleading problem, since it illustrates the uncertainty as to what complaints are being relied upon for the claim in negligence. 108 In Re Bega Co-operative Society Ltd & Anor v The Milk Authority of the Australian Capital Territory & Anor [1997] FCA 200, at [24], Neaves J summarised the relevant principles and noted that not only must all material facts be pleaded (those being all facts necessary for the purpose of formulating a complete cause of action) but they must be pleaded with a sufficient degree of specificity, having regard to the general subject matter of the claim, to convey to the opposite party the case that party has to meet (there citing Ratcliffe v Evans (1892) 2 QB 524, at 532; Charter Carter Pty Ltd v The Shop, Distributive and Allied Employees' Association of Western Australia (1987) 13 FCR 413, at 417. 109 The fact that paragraph 29 does not make clear the facts which are the subject of the relevant complaints and in respect of which it is said there is a claim in negligence, makes this paragraph vague and embarrassing and liable to be struck out. 110 Further, the basis on which it is alleged that a duty of care arose is not articulated (whether in the pleaded paragraph or the particulars appended to it). Even taking into account what appears in the particulars, the pleading is deficient in this material respect. In submissions the duty was put by reference to the proximity of Mr and Mrs Quick as lower lying landowners. Paragraph 6 of the Amended Statement of Claim does plead the proximity of the properties in question and that water naturally flows from the Alpine Nursery land on to the Quick Property (also pleading the location of the Alpine Nursery by reference to the Marom Creek Weir). However, the defendants should not be left to guess from assertions contained in other paragraphs the facts on which the plaintiffs rely for the allegation that there was a duty of care as alleged (be that a duty not to expose Mr and Mrs Quick to the risk of damage resulting from a more concentrated flow of water from the higher lying land or from the escape of polluted water from that land). 111 Moreover, the fact that Mr and Mrs Quick are lower lying landowners of itself could not readily explain how it is alleged that a duty owed to Mr and Mrs Quick to comply with relevant Council consent conditions had arisen (and, for that matter, the 'relevant' consent conditions are not themselves specified - though arguably this might be surmised by reference to those consent conditions itemized elsewhere in the pleading such as in the particulars provided of the alleged breach). 112 What complicates the consideration of this initial pleading issue is that the so-called 'particulars' to paragraph 29 themselves contain many (though not all) of the material facts on which it appears that Mr and Mrs Quick rely for the allegation of negligence (those having been added by way of amendment to the pleading pursuant to directions made by Registrar Walton on 19 December 2008). 113 Even leaving aside the failure to plead the material facts on which Mr and Mrs Quick rely for the allegation that a duty of care was owed to them, particulars are provided of the content of that duty of care and as to the alleged breach of the duty of care, albeit not in a definitive way. 114 As particularised, the duty of care is said to 'include' a duty: (a) not to expose occupiers of lower lying lands to an increased and/or more concentrated and/or faster flow of water onto their land; (b) not to allow polluted water to escape from their land; and (c) to comply with all 'relevant' consent conditions imposed by the Council (though, as noted above, the conditions referred to in (c) are not specified other than so far as they can be discerned from the particulars provided of breach of duty of care; though various consent conditions to the successive development applications having been pleaded in the body of the pleading). 115 A pleading that "includes" matters, without being exhaustive of the matters on which the plaintiff may seek to rely, is also vague and embarrassing (albeit that it might perhaps be possible to cure that defect by reading down the scope of the allegation to what has in fact been articulated). 116 The particulars of the alleged breach of the duty of care are given by reference to six separate sets of facts and circumstances (said to be relied upon as constituting acts or omissions by the defendants "amounting to breach of duty of care"), those in turn being further particularised by the provision of some particulars of the alleged failures. Again, the particulars so provided suffer from the defect that they are said to 'include' the matters set out therein and thus are not definitive. 117 The six sets of facts and circumstances as particularised are as follows: (a) failure to comply with consent conditions imposed by the Council [and the particular conditions are there itemized by reference to particular clauses or portions of the conditions imposed by Council on 29 March 2004 and 25 July 2006, though it is not said how those conditions have been]; (b) failure to ensure that the development of, and operations conducted on the Alpine property did not increase the flow of water, or damage the quality of water, flowing on to the Quick Property [by reference to the allegations of use of the property as a nursery contained in paragraphs 19 and 20 and the alleged failure to provide a 'full' Environmental Impact Statement for a zone 7(c) development]; (c) failure to install adequate or any safeguards to ensure that polluted or nutrient rich water did and does not flow on to the Quick Property [those safeguards said to be a matter for evidence but to include leaving sufficient land between the retention dam wall and the Ellis Road culvert to allow 'a proper riparian zone' to be developed; constructing a secondary retention dam 'in accordance with recognized best practice'; and not covering approximately 90% of the surface of the property with impervious black sheeting so as to allow the natural soil to absorb run-off and filter nutrients, chemicals and to purify groundwater flowing onto the Quick Property] ; (d) failure to comply with standard testing procedures and practices recommended by the NSW Department of the Environment, thereby exposing the Plaintiffs to the flow of toxic chemicals [referring to the letter dated 28 May 2008 from the Department of Environment and Conservation NSW by way of example]; (e) failure to comply with s 96 Clean Up Order issued by Ballina Shire Council [referring to an alleged failure to comply with a Prevention Notice dated 17 May 2005 and correspondence in September/October 2005]; and (a) failure to comply with procedures and practices recommended by NSW Department of the Environment and Climate Change including maintaining an accurate chemical register and Safe Chemical use practices [again referring to the Department's letter]. 118 The Further Amended Defence, filed on 5 April 2010 pursuant to orders made by the Registrar on 1 April 2010, responded to paragraph 29 of the Amended Statement of Claim as follows (and I set this out in full because it seems to me that it is relevant that there was no apparent attempt by Mr and Mrs Quick to address the complaints raised therein by seeking further to amend their pleading): The Defendants deny the contents of paragraph 29. In further answer, they say that this paragraph does not plead a justiciable cause of action. It is vague and embarrassing. In the way in which it is pleaded, it is inconsistent with the most basic rules of pleading. For example (and without being exhaustive): (a) A party must plead all the material facts on which he relies for his claim (see: UCPR 14.7 and, for example, Phillips v Phillips (1878) 4 QBD 127 at 133). The paragraph contains no pleading of any material fact, let alone all of the material facts on which the Plaintiffs rely; (b) The omission of the material facts necessary to complete a cause of action cannot be supplied by particulars (see, for example: Bruce v Odhams Press Ltd [1936] 1 KB 697); (c) It is not sufficient to simply plead [sic] a conclusion drawn from unstated facts (see, for example: Trade Practices Commission v David Jones (Australia) Pty Ltd (1985) 7 FCR 109 at 114-115 per Fischer J); (d) Even if it were permissible to rely on particulars (which, for the reasons set out above, it is not), then the way in which the duty of care is asserted is embarrassing. The basis upon which a duty is said to exist is not asserted; (e) Then, the duties said to be owed are themselves, embarrassing. For example: (c) provides no specificity in relation to that which are relied on as the "consent conditions imposed by Council"; (f) When dealing with what are said to be the breaches of the asserted duties, the pleading uses the word "include". The pleading must identify the breaches relied on. If the use of the word include conveys that there may be others relied on, then they need to be identified. If they are not, then they cannot be introduced later. None of the material facts relied on to support any of the breaches are pleaded. Consequently, all of the "failures" pleaded are embarrassing. 119 As to the allegation of loss and damage in paragraph 30, the defendants not only deny the contents of that paragraph of the Amended Statement of Claim, they also allege that it is embarrassing and should be struck out on the basis that it is impermissible merely to plead the conclusion, that is, a claim for loss and damage, without identifying what that loss and damage is, and how it is said to arise (again citing Trade Practices Commission v David Jones (Australia), at 114-115). 120 Mr Kerr submits that the deficiencies in the pleading of the claim in negligence cannot be remedied by recourse to particulars, relying on Bruce v Odhams Press Limited [1936] 1 KB 697, and adopts the reasoning contained in paragraphs [406] – [420] in Brand v Monks [2009] NSWSC 1454. In Odhams Press, at 712-713, Scott LJ considered the function of particulars as distinct from the requirement to plead material facts, the latter comprising what was necessary for the purpose of formulating a complete cause of action and the former having the function of filling in the picture of the cause of action with information sufficiently detailed to put the defendant on his guard as to the case he has to meet and to enable him to prepare for trial. 121 In both Odhams Press and Pinson v Lloyds and National Provincial Foreign Bank Limited [1941] 2 KB 72, at 75-76, Scott LJ emphasised that particulars are "not to be used in order to fill material gaps in a demurrable statement of claim - gaps which ought to have been filled by appropriate statements of the various material facts which together constitute the plaintiff's cause of action", though recognising that: … in practice it is often difficult to distinguish between a "material fact" and a "particular" piece of information which it is reasonable to give the defendant in order to tell him the case he has to meet; hence in the nature of things there is often overlapping. 122 Scott LJ's conclusion that "in strictness particulars cannot cure a bad statement of claim" was cited with approval in Rubenstein v Truth and Sportsman Limited [1960] VR 473, at 476 by Adam J (who considered that the preferable course, where there had been a clear infringement of the rule as to stating all material facts and not merely a failure to give sufficient particulars of facts which have been pleaded, was to strike out the offending pleading (albeit with liberty to amend) rather than to order particulars), H 1976 Nominees Pty Limited v Galli (1979) 30 ALR 181, by Northrop J and Bega Co-Operative Society, per Neaves J. In McFadzean v CFMEU [2004] VSC 289, at [2607] (per Ashley J) and in Shanmugaratnam v Strasburger Enterprises (Properties) Pty Ltd [2004] NSWCA 229 (per Mason P, with whom Santow JA and Cripps AJA agreed), it was accepted that it is not the function of particulars to expand a pleading. 123 I agree that it is not the function of particulars, strictly speaking, to amend or expand pleadings and I accept Mr Kerr's submission that inadequately or improperly pleaded complaints should not ordinarily be determined by what is contained in the particulars. It seems to me that those occasions when particulars have been allowed in effect to expand the scope of a pleaded case can best be seen as an application of the principle that parties may by their conduct of the case acquiesce in a departure from, or may disregard or enlarge, a pleaded case (or, as it was put by Spigelman CJ in Vines v Australian Securities and Investments Commission (2007) 73 NSWLR 451; (2007) 62 ACSR 1; [2007] NSWCA 75, at 17 [57], may choose to fight the case on a different basis). 124 Here, there can be no suggestion that the defendants have acquiesced in any enlargement or expansion of the pleaded case by reference to the particulars. The Further Amended Defence makes it very clear that the defendants objected not only to the pleading as it stood but also to any reading of the particulars as curing the defects in the pleading of negligence (and, somewhat unusually for a pleading of this kind, outlines in detail the basis of their objection in that regard). In those circumstances, the plaintiffs were clearly put on notice of the defendants' objection to reliance on the particulars to supply the material facts missing from the pleaded case in negligence and, whether or not they agreed with the objections so raised, had the opportunity to address them. They did not do so. I can only assume that they chose to conduct the case on the basis that if the plea in negligence were to be found deficient (without reference to the particulars) then it was liable to be struck out. 125 In the Court of Appeal in Ingot Capital Investments Pty Limited v Macquarie Equity Capital Markets Limited (2008) 73 NSWLR 653; (2008) 252 ALR 659; (2008) 68 ACSR 595; [2008] NSWCA 206, Ipp JA noted that at trial there may be a departure from the pleadings where adherence to them would be unjust or unfair (citing Banque Commerciale SA (in liq) v Akhil Holdings Ltd (1990) 169 CLR 279; 92 ALR 53; [1990] HCA 11, per Mason CJ and Gaudron J (at CLR 286–7; ALR 58–9)). His Honour also noted that the rule that, in general, relief is confined to that available on the pleadings is a rule that secures a party's right to a basic requirement of procedural fairness. 126 Here, it seems to me that there is nothing unfair in holding Mr and Mrs Quick to their pleaded case and, it not having been properly pleaded, I am of the view that the claim in negligence was liable to be struck out and should not be entertained. As Einstein J said in Travel Compensation Fund v Blair [2003] NSWSC 720, at [30], it is simply not the function of particulars to take the place of necessary averments in the pleading of the material facts. There is nothing to indicate any acquiescence by the defendants or any conduct (in the words of Ipp JA) on their part sufficient to ground an inference that the parties had chosen a different basis to that evident on the pleaded issues for the determination of their respective rights and liabilities. 127 Accordingly, the claim in negligence cannot be maintained. (b) Nuisance – Paragraphs 24 - 28 of Amended Statement of Claim 128 The claim in nuisance is pleaded in paragraphs 24-28 of the Amended Statement of Claim. 129 Paragraph 24 alleges that "the volume and velocity of water flowing, and the incidence of flooding and water seepage from the Alpine Nursery land on to the Quick Property" has substantially increased since the construction of the water retention dam 1 and the commencement of commercial nursery operations on the Alpine Nursery land in 2004, and caused material damage to the Quick Property. 130 Paragraph 25 alleges that as a result the conduct of the defendants in "altering the conformation of the property (as set out above)", there has been a material increase in the "flow or percolation of water" from the Alpine Nursery land on to the Quick Property resulting in damage. 131 Those are the only matters said in paragraphs 26 and 27 to have interfered with the enjoyment of the Quick Property and to have constituted a nuisance that was and is caused, continued or adopted by the defendants. 132 There is no reference in paragraphs 24 to 27 (in which the claim in nuisance is expressly pleaded) to the use of chemicals on the Alpine Nursery land (whether by way of fertilizer or aerial spraying) giving rise to water pollution or air pollution), or to the noise or increased traffic caused by the Alpine Nursery operations, or to the quality of the water leaving the Alpine Nursery land, or (other than insofar as the reference a material increase in water percolation or water seepage onto the Quick Property raises this issue – and it surely cannot do so since the thesis of the plaintiffs is that the level of the subsurface water under their property has decreased) to the reduction of subsurface water or lowering of the regional water table. 133 Mr Kerr submitted that the plaintiffs, in those circumstances, should be taken to have decided to raise just two of the myriad of complaints made by them since the commencement of the Alpine Nursery operations. If so, then paragraph 20 of the Amended Statement of Claim sits somewhat oddly in the pleading. That paragraph (under the heading 'The impact of Alpine's operations'), which in its terms seems directed to an allegation of nuisance, is as follows: 20. Construction and use of the water storage facility, and use of the Alpine property as a wholesale nursery, and in particular covering large portions of it with impervious plastic sheeting and intensively watering nursery plants on at least a daily basis, and using and spraying fertilizers, pesticides and other chemicals, constitutes a non-natural use of the Alpine property. 134 Perhaps it might be said that the additional conduct referred to in this paragraph goes only to the question whether the nursery operations constitute a natural or non-natural use (assuming a substantial and unreasonable interference with the plaintiffs' enjoyment of their property in the more limited ambit described in paragraphs 24 and 25 is otherwise established) and hence that there is no inconsistency. Whether or not that is the proper reading of the interaction between these parts of the pleading, paragraphs 24 to 27 in my view base the plea in nuisance solely on the matters referred to therein and hence that claim does not extend to any interference constituted by matters other than those alleged in those paragraphs. 135 The particulars provided of the loss and damage said to have been suffered as a result of the pleaded nuisance (appended to paragraph 28) do refer to matters going beyond those identified as amounting to nuisance (in the particulars, water pollution is raised expressly in paragraph (b) and implicitly in paragraph (c); air pollution is raised in paragraph (e); and the lowering of the water table and reduction in volume of water available in bores in paragraph (g). Loss of enjoyment (in paragraph (h)) is particularised by reference to pollution, spraying and increased noise and traffic caused by nursery operations on the Alpine Nursery land. However, the difficulty in reading these particulars of loss and damage as expanding the claim in nuisance is that adverted to in considering the negligence claim above. Although it might be said that the plaintiffs were not so directly put on notice of a complaint in this regard (as it was not incorporated into the Further Amended Defence), it seems fair to say that Mr Kerr made his objection to this very clear when addressing the question of the admissibility of evidence going to matters such as the aerial spraying and the ambit of the concurrent evidence (and, I might add, at the conclusion of Mr Philips' cross-examination of Mr Wilson when I had contemplated, and was firmly discouraged by Mr Kerr, from raising the issue of aerial spraying with the witness). 136 It seemed to me that it was not necessarily inconsistent with the claim in nuisance being limited to what I might refer to as the water flow issues that the plaintiffs might seek to establish that the damage suffered as a result of a substantial increase in the flow or concentration of water arriving on the property was due to there being a larger quantity of polluted water than would otherwise have arrived on the property. In other words, it seems to me on the pleading that complaints as to the quality of that water could still be made when going to the damage suffered (rather than water pollution itself constituting the nuisance). I was thus of the view that evidence in relation to factual matters of that kind might have some potential relevance notwithstanding that they had not been pleaded as acts constituting the nuisance itself (and thus not for the purpose of establishing any act of nuisance). (As it turned out, the evidence relating to matters such as air pollution and noise was largely limited to the lay observations of Mr and Mrs Quick and did not in my view establish that loss or damage had been sustained as a result of the actual nuisance pleaded but I deal with that issue in due course.) 137 The reference in paragraph 25 to the defendants' actions "in altering the conformation of the Alpine property as set out above" can only refer to the construction and use of the water storage facility (water retention dam No 1) and covering the property with impervious plastic sheeting (paragraph 20, paragraph 19(a)) and/or the creation of the nursery garden beds and internal roads (paragraph 19(b)) not the creation of the ridge on the eastern side of the property (unless the plaintiffs are seeking to import into this reference alterations the subject of the Council consent referred to in paragraph 23, but if the latter is the case I think the pleading is not sufficiently clear and hence objectionable in any event). 138 Having regard to the matters considered above in relation to the distinction between a pleading of material facts necessary to ground a cause of action and the provision of particulars, I find that Mr and Mrs Quick are not able to maintain a claim in nuisance in relation to interference with the enjoyment by them of their property other than as pleaded in paragraphs 24-25 of the Amended Statement of Claim namely, by reference to the alleged increase in volume and velocity of water flowing onto their property, alleged increase in water seepage or percolation of water, and alleged increased incidence of flooding; and that they are limited in so doing to the allegation that these have resulted from the alterations in conformation or use of the Alpine Property earlier pleaded in the Amended Statement of Claim (which does not include the eastern ridge earthworks). (ii) Claim in Nuisance 139 Turning then to the claim in nuisance which was pleaded, it was accepted by both parties that the principles to be applied in considering whether the defendants are liable for nuisance require consideration as to whether there has been a substantial and unreasonable interference in the enjoyment of the Quick Property. Legal Principles Requirement for fault? 140 Although it was initially contended for Mr and Mrs Quick that the fact that the defendants had taken all reasonable care would not of itself exonerate them from liability (citing Cambridge Water Co v Eastern Counties Leather [1994] 2 AC 264, at 300F per Lord Goff), during the course of argument it was accepted by Mr Philips that liability for nuisance (unless the conduct gave rise to a claim of strict liability) would not be established unless it could be shown that that the defendants had acted recklessly or had either failed to take action or taken action knowing the likely impact on the enjoyment by Mr and Mrs Quick of their property. 141 As noted by Bryson JA in Sutherland Shire Council v Becker [2006] NSWCA 344, at [119] and Preston CJ in Robson v Leischke [2008] NSWLEC 152; (2008) 72 NSWLR 98; (2008) 159 LGERA 280 (at [44]-[46]), the tort of nuisance involves fault of some kind or another (their Honours each citing Overseas Tankship (UK) Ltd v Miller Steamship Co Pty (The Wagon Mound (No 2)) [1967] 1 AC 617, at 639 and Montana Hotels Pty Ltd v Fasson Pty Ltd (1986) 61 ALJR 282, at 284, (1986) 62 LGERA 46, at 50-51 for this proposition. That fault generally involves foreseeability (Preston CJ in Robson citing The Wagon Mound (No 2), at 639-640; Leakey v National Trust for Places of Historic Interest or Natural Beauty [1980] QB 485, at 522, 524; Solloway v Hampshire County Council (1981) 79 LGR 449, at 452, 457-458, 460 and 461; City of Richmond v Scantelbury [1991] 2 VR 38, at 45; Cambridge Water, at 300; Delaware Mansions Ltd v Westminster City Council [2002] 1 AC 321, at 332 [29]). Liability for nuisance, therefore, is not strict liability (there citing Sedleigh-Denfield v O'Callaghan [1940] AC 880, at 904). 142 In Robson, Preston CJ went on to explain how the type of fault required to establish the tort of nuisance depends upon whether the defendant created the nuisance or had, rather, adopted or continued the nuisance, stating (from [47]): Where the defendant created the nuisance, the fault element varies depending on the nature of the defendant's conduct and his or her state of knowledge. Clerk & Lindsell on Torts identify three situations where the defendant has created the nuisance: (a) "if the defendant deliberately or recklessly uses his land in a way which he knows will cause harm to his neighbour, and that harm is considered by a judge to be an unreasonable infringement of his neighbour's interest in his property, and therefore an unreasonable user by the defendant of his property, the defendant is liable for the foreseeable consequences. This proposition covers all those cases of obvious or "patent" nuisances, and they are peculiarly the cases which call for prevention or prohibition by injunction. It is no defence that the defendant believed he was entitled to do as he did or that he took all possible steps to prevent his action amounting to a nuisance": Clerk & Lindsell on Torts , 19th ed, Sweet & Maxwell, London, 2006, [20-39], p 1184; (b) "if the defendant knew or ought to have known that in consequence of his conduct harm to his neighbour was reasonably foreseeable, he is under a duty of care to prevent such consequences as are reasonably foreseeable. In such case the defendant is liable because he is considered negligent in relation to his neighbour, and here nuisance and negligence coincide": Clerk & Lindsell on Torts , 19th ed, Sweet & Maxwell, London, 2006, [20-40], p 1185; and (c) "If the defendant neither knows and intends harm nor is negligent with regard to the consequences of his conduct, then he may be nevertheless liable if the claimant can bring his case within the rule in Rylands v Fletcher (1868) LR 3 HL 330, and in that event there is strict liability": Clerk & Lindsell on Torts , 19th ed, Sweet & Maxwell, London, 2006, [20-41], p 1185. However, in Australia, strict liability within the rule in Rylands v Fletcher has been subsumed within the law of negligence by the High Court decision in Burnie Port Authority v General Jones Pty Ltd (1994) 179 CLR 520. Strict liability can, however, be reintroduced by statute. Where the defendant continues or adopts a nuisance, different conduct is required before liability will be imposed on the defendant. An occupier of land "continues" a nuisance or a potential nuisance if, with actual or constructive knowledge of its existence, he or she fails, within a reasonable period of time, to take reasonable measures to bring it to an end: Sedleigh-Denfield v O'Callaghan [1940] AC 880 at 894, 904-905, 913; Torette House Pty Ltd v Berkman (1940) 62 CLR 637 at 657-658; Montana Hotels Pty Ltd v Fasson Pty Ltd (1986) 62 ALJ 282 at 284, (1986) 62 LGRA 46 at 50; City of Richmond v Scantelbury [1991] 2 VR 38 at 41, 42; Proprietors of Strata Plan No 14198 v Cowell (1989) 24 NSWLR 478 at 484; Delaware Mansions Ltd v Westminster City Council [2002] 1 AC 321 at 332 [29]. 143 Similarly, in Rickard & Ors v Allianz Australia Insurance Ltd & Ors [2009] NSWSC 1115 (23 October 2009), the Court cited with approval what had been said by Bryson JA in Becker as to the requirement for fault in cases other than those of strict liability and considered what was necessary to show the requisite degree of knowledge for the purposes of nuisance, saying later at [188] – [189]: As Lord Wright made clear in Sedleigh-Denfield , constructive knowledge for the purposes of nuisance does not equate with foreseeability in negligence. The test is not whether a risk is far fetched or fanciful, but whether there is evidence of facts, matters or circumstances from which the defendant ought to have known of the nuisance. In this case that means "ought to have actual knowledge of the fact of water flowing directly from the driveway across the highway", not, "ought to have foreseen the risk that water might flow directly from the driveway across the highway if a sufficiently severe rainfall event were to occur at some time in the future". 144 Here, assuming for practical purposes that the consequences on the water flow from the Alpine Nursery property were to have been as pleaded, the question is whether in respect of any nuisance so created the defendants had actual or constructive knowledge (at the time they took the action which gave rise to those consequences – be it construction of the No 1 water retention dam or the laying of the black plastic sheeting or the compaction of the gravel on the internal roadways or the nightly irrigation) of the likely consequences of that action. 145 There is nothing to show an actual knowledge that the actions in question would have the effect that it is contended they have had. Mr Philips submitted that the defendants had been reckless in the way that they had used the Alpine Nursery property, as demonstrated by the fact that the No 1 water retention dam was of less capacity than specified in the application for development consent; that the management plan prepared after the May 2005 outbreak showed that the dam was bound to fail and that the construction of the levy bank to stop silt from adjoining properties coming onto the property showed that they were preferring their own commercial interests. For the reasons set out below, I am not satisfied that the evidence supports a finding of recklessness. 146 As to constructive knowledge, the defendants must surely be taken to have known that there was a possibility that the dam would overflow (since the development consent conditions expressly make provision for the spillway) and that if it did so the water would flow onto the Quick Property through the Ellis Road culvert (since that must be the consequence of the culvert being at that point of the road). They clearly knew that irrigation on the areas covered by black plastic sheeting would drain to No 1 water retention dam (but I am not satisfied that they knew or ought to have known that this would have the effect for which the plaintiffs' expert contends - their consultant being of the view that this was something that would lessen the flow of water off the property). They were also aware that rainwater on the internal roads would be diverted around the dam to the bottom swale and thence to the culvert (again, since this was a feature of the water management plan put forward to the Council). 147 However, for there to be liability for the creation of a nuisance (as opposed to its continuation or adoption), in the absence of deliberate use of the land, there must be recklessness as to the use of the land in a way which the defendant knows will cause harm or the requisite knowledge or constructive knowledge that, in consequence of the defendant's conduct, harm was reasonably foreseeable. In light of Mr Rolfe's evidence, which I accept, it cannot be said that the defendants ought to have known that harm was likely to be caused by the conduct in question even though they were on notice of the matters set out in the preceding paragraph. Significant in this regard is the fact that Mr Rolfe, the consultant who designed or was principally involved in designing the irrigation and drainage scheme for the nursery and an industry expert, said that, consistent with best industry practice, consideration had been taken of the impact of the nursery on the downstream neighbours and he had formed the view that the plan adopted meant that the net result of the irrigation and drainage system would be that the amount of water flowing from the Alpine Nursery property would be the same. It seems to me that this disposes of the allegation of recklessness and of any allegation based on constructive knowledge of the harm. 148 Therefore, I find that the requisite element of fault has not been established for the allegation that the defendants created any nuisance of the kind pleaded. 149 Of course, in the present case, the allegation made against the defendants is not only that they created the nuisance but also that they continued and adopted it. In Robson, Preston CJ considered what was meant by adoption of a nuisance: An occupier of land "adopts" a nuisance if he or she makes use of "the erection, building, bank or artificial contrivance" or the natural object (such as a tree) which constituted the nuisance: Sedleigh-Denfield v O'Callaghan [1940] AC 880 at 894, 904, 913; Proprietors of Strata Plan No 14198 v Cowell (1989) 24 NSWLR 478 at 484. An occupier of land who knows or ought to know of a nuisance, and the possibility of danger occurring in consequence is a real risk, must take such positive action as a reasonable person, in his position and circumstances, would consider necessary to eliminate the nuisance: Clerk & Lindsell on Torts , 19th ed, Sweet & Maxwell, London, 2006, [20-42], p 1185-1186; Sedleigh-Denfield v O'Callaghan [1940] AC 880 at 894, 904-905, 913; Montana Hotels Pty Ltd v Fasson Pty Ltd (1986) 61 ALJ 282 at 284, (1986) 62 LGRA 46 at 50; City of Richmond v Scantelbury [1991] 2 VR 38 at 40, 42, 43, 45, 46; Delaware Mansions Ltd v Westminster City Council [2002] 1 AC 321 at 332 [29], 333 [31]; and South Australia v Simionato (2005) 143 LGERA 128 at 141 [52]-[53], 142 [56]. Knowledge of the nuisance, actual or constructive, is insufficient by itself to render an owner or occupier liable for damage caused by it; arising out of such knowledge is a duty on the occupier to take steps to eliminate the risk of damage from the nuisance which is reasonably foreseeable: Overseas Tankship (UK) Ltd v Miller Steamship Co Pty (The Wagon Mound (No 2)) [1967] 1 AC 617 at 639; City of Richmond v Scantelbury [1991] 2 VR 38 at 45; Malliate v Sharpe [2001] NSWSC 1057 (13 December 2001) at [43], [44]. The defendant will be liable if, when the nuisance arose, the defendant did not take any reasonable means to bring it to an end when the defendant became aware, or ought to have been aware, of the existence of the nuisance, and damage results: Valherie v Strata Corporation No 1841 and Ors [2004] SASC 170 (9 June 2004); 234 LSJS 134 at 14 [33], [34], [36], 143 [44]; Sutherland Shire Council v Becker (2006) 150 LGERA 184 at 226 [121]. 150 Therefore, if there has been a nuisance by reason, for example, of the nightly irrigation which is ongoing but the defendants did not have the necessary knowledge to establish fault in relation to the implementation of that system of irrigation, they might nevertheless be liable for the continuation or adoption of that nuisance if (having become aware that it has adverse consequences in terms of water flow) they thereafter took no steps of a kind which would be reasonable or practicable to minimise the adverse effect of such irrigation. 151 In relation to nuisance based on physical damage, an affirmative duty to take action arises where the defendant has, or ought to have had, knowledge of the existence of a defect in the land or something on it and the danger thereby created (Goldman v Hargrave [1967] 1 AC 645, at 663-664; Leakey, at 522; Smith v Littlewoods Organisation Ltd [1987] AC 241, at 279; Robson, at [72]). In relation to the defendant's duty to take affirmative action to prevent damage occurring to the plaintiff's property, so as to avoid liability in nuisance, Preston CJ said in Robson (from [73]): The scope of the duty is: "a duty to do that which is reasonable in all the circumstances, and no more than what, if anything, is reasonable, to prevent or minimise the known risk of damage or injury to one's neighbour or to his property. The considerations with which the law is familiar are all to be taken into account in deciding whether there has been a breach of duty, and, if so, what that breach is, and whether it is causative of the damage in respect of which the claim is made. Thus, there will fall to be considered the extent of the risk; what, so far as reasonably can be foreseen, are the chances that anything untoward will happen or that any damage will be caused? What is to be foreseen as to the possible extent of the damage if the risk becomes a reality? It is practicable to prevent, or to minimise, the happening of any damage? If it is practicable, how simple or how difficult are the measures which could be taken, how much and how lengthy work do they involve, and what is the probable cost of such works? Was there sufficient time for preventive action to have been taken, by persons acting reasonably in relation to the known risk, between the time when it became known to, or should have been realised by, the defendant, and the time when the damage occurred? Factors such as these, so far as they apply in a particular case, fall to be weighed in deciding whether the defendant's duty of care requires, or required, him to do anything, and, if so, what": Leakey v National Trust for Places of Historic Interest or Natural Beauty [1980] QB 485 at 524. The duty of care is not that of the reasonable man in negligence, but rather it is measured by the reasonable capabilities and circumstances of the defendant: Goldman v Hargrave [1967] 1 AC 645 at 663; Leakey v National Trust for Places of Historic Interest or Natural Beauty [1980] QB 485 at 526. As noted above, the defendant's liability for a nuisance of this second kind will depend on the defendant either having created the nuisance (such as by doing the acts which caused the defect and the danger) or by adopting or continuing the nuisance (which require the defendant to have actual or constructive knowledge of the defect and the danger thereby created). 152 Consistently with the above principles, if the existence of the black plastic sheeting or the No 1 water retention dam or the practice of almost nightly irrigation is now shown to be (or to be likely in future to be) an unreasonable interference with the enjoyment of the Quick Property and the defendants were on notice of that at some time after the development of the nursery took place, then whether the defendants have any liability for the continuation or adoption of the nuisance would depend on whether they had taken reasonable or practicable steps to prevent the harm. In that regard, if the steps taken to minimise the overflow from No 1 water retention dam (including the pumping of water from the dam in times of anticipated overflow and maintaining headspace in the dam in accordance with the best nursery practice) and the steps taken to restrict the irrigation to the garden beds are not sufficient to avoid harm occurring, could it be said that the defendants had taken all reasonable and practicable steps to avoid the harm? 153 Mr Wilson's evidence was that the system can pump up to a megalitre of water in a 24 hour period. In cross-examination, Mr Wilson suggested that a mining pump might be able to pump water faster out of the dam (ie faster than the present equipment) but, as emphasised by Mr Kerr in closing submissions, there was no evidence that this would be a feasible measure (and it seemed to me that this was put forward almost as an afterthought rather than as a seriously considered alternative to the present situation.) Mr Wilson's evidence appeared to be that the incidence of dam overtopping is now reduced from the initial phases of the nursery operations. Similarly, while Mr Dey proffered some suggestions as to remedial measures he himself expressed no opinion as to whether they would be effective. 154 As a matter of logic, if the head space in the No 1 water retention dam were to be sufficient to allow for retention of the greatest volume of water likely to fall onto the property in times of the heaviest anticipated rainfall, then this surely would minimise, if not wholly exclude, the possibility of overflow. However, in circumstances where the defendants' evidence is that the maximum head space for which they allow is consistent with best industry practice, it might be said that it is unreasonable for there to be any further accommodation in this regard, particularly since the capacity to pump water from the dam must also be taken into account. 155 Emphasis was placed on the steps which have been taken by the defendants to address concerns in relation to the water management system (which Mr Rolfe suggested were unparalleled in the Australian nursery industry). In those circumstances it is difficult to find that the defendants have not taken reasonable and practicable steps to minimise the risk of harm from the dam overflowing. 156 Therefore, had I found that there had been an adoption or continuation of a nuisance in this regard (which I do not) I would have been inclined to find that there was nevertheless no liability for that nuisance on the basis that the defendants had taken reasonable steps to remedy the nuisance. 157 On balance, therefore, even if the water flow interference could be said to have amounted to a substantial and unreasonable interference with the user of the Quick Property (and for the reasons below I do not consider that it can), I find that the plaintiffs have failed to establish the requisite element of fault for the creation and/or adoption or continuance of the situation giving rise to the alleged water flow interference (and hence no liability for nuisance would arise on the part of the defendants in any event). Unreasonable interference? 158 Turning then to the question whether the events in question constitute an undue interference with the comfortable and convenient enjoyment by Mr and Mrs Quick of their land caused by the defendants' actions, this turns on whether there has been an excessive user by the defendants of their land resulting in what is considered to be an unreasonable interference with the enjoyment by the plaintiff of his land, having regard to the ordinary usages of humankind living in a particular society (Robson, at [84]). 159 In Bayliss the Full Court of the Supreme Court of New South Wales said the Court's task was to reconcile the conflicting aims of adjoining landowners by effecting a compromise, and approved the following statement by Fleming on Torts 2nd ed, Clarendon Press, 1961, at 400-1: "The paramount problem in the law of nuisance is, therefore, to strike a tolerable balance between conflicting claims of landowners each of whom is claiming the privilege to exploit the resources and enjoy the amenities of his property without undue subordination to the reciprocal interests of the other . Reconciliation has to be achieved by compromise, and the basis for that adjustment is reasonable user. Legal intervention is warranted only when an excessive use of property causes inconvenience beyond what other occupiers in the vicinity can be expected to bear, considering the prevailing standard of comfort of the time and place . Reasonableness in this context is a two-sided affair. It is viewed not only from the standpoint of the Defendant's convenience, but must equally take into account the interest of the surrounding occupiers. It is not enough to ask: Is the Defendant using his property in what would be a reasonable manner if he had no neighbour? The question is: Is he using it reasonably, having regard to the fact that he has a neighbour ?" (my emphasis) 160 In Michallef v Galea [2001] NSWSC 984, Austin J referred (at [17]) to the majority decision in Elston v Dore (1982) 149 CLR 480, where (at 488) "the proper test to apply in most cases" concerning what would be considered reasonable use was the following statement by Lord Wright in Sedleigh-Denfield (at 903): It is impossible to give any precise and universal formula, but it may broadly be said that a useful test is perhaps what is reasonable according to the ordinary uses of mankind living in society, or more correctly in a particular society. 161 The majority in Elston v Dore, then went on to say; Although the wide and uncertain boundaries of the law of nuisance include cases in which negligence in the narrow sense is not essential, fault of some kind is almost always necessary. In the present case the action of the respondent was deliberate, but in our opinion it will only have been wrongful if it was not reasonable in the sense to which Lord Wright refers. 162 In Melaleuca, Giles JA (with whom McColl JA and Hunt AJA agreed) said (at [22]): For the legal wrong of (private) nuisance, a nuisance is an unreasonable interference with the use and enjoyment of land: an "invasion of the common law rights of an owner or occupier of land" ( Hargrave v Goldman (1963) 110 CLR 40 at 60 per Windeyer J). Preferably used, the word denotes the result of the defendant's conduct, or perhaps the state of affairs created by the conduct and bringing about the result. Thus in Torette House Pty Ltd v Berkman (1940) 62 CLR 637, in which water discharged from the defendant's premises onto the plaintiff's premises, Dixon J said (at 657) that there was "no nuisance or other wrongful act on the part of anyone of which the plaintiff could complain until the water began actually to flow onto the plaintiff's premises". Also preferably used, finding a nuisance does not mean legal liability for the result of the defendant's conduct. In some circumstances there may be an unreasonable interference with the use and enjoyment of the plaintiff's land without liability in the defendant . (my emphasis) 163 In determining whether there has been an unreasonable interference with the owner or occupier's enjoyment of the land, a balance must be maintained between the right of the defendants to do what they like with their own land and the right of Mr and Mrs Quick not to be interfered with (Sedleigh-Denfield, at 903; Bayliss, at 529-530, 542, see also Don Brass Foundry Pty Ltd v Stead (1948) 48 SR (NSW) 482, at 486-488). As noted in Robson by Preston CJ (at [54]), "the tipping point in the balance is where the consequences of the use by the first person of his or her land unduly interferes, in ways recognised by the law as constituting a nuisance, with the use and enjoyment by the neighbour of his or her property". 164 In carrying out the balancing exercise in the present case, it is relevant to note that the Quick Property has for some time been prone to the incidence of flooding and that the southern paddock forms part of the natural watercourse for water flowing from neighbouring properties down to Marom Creek. Therefore, the fact that the paddock floods on occasion (and even, perhaps, that it floods more often as a consequence of the operations of the Alpine Nursery) does not suggest that there is an excessive user on the part of the defendants at the expense of Mr and Mrs Quick. Further, if the reason that the southern paddock has been waterlogged and unusable for some time is or may be due (as I think seems likely) at least in part to the failure of Mr Quick to remove debris from the boundary fence and to maintain the paddock (and/or the paper road) in such a fashion as to allow the ready flow of water off the property, then the balancing exercise seems to me to lead to the conclusion that there has not been an unreasonable interference with the enjoyment by Mr and Mrs Quick of their property. 165 Therefore, I am of the opinion that even if there has been water flow interference of the kind pleaded (which I think there had not) as a result of the defendants' actions (and, for the reasons set out below, I am not satisfied that that is the case) I would not have found that, in the circumstances, it amounted to an unreasonable interference with the plaintiffs' rights in relation to their land for the purposes of the tort of nuisance. Proof of loss not necessary 166 Where a plaintiff relies upon an interference of the type considered above to ground a claim in nuisance, it will not be necessary for the plaintiff to prove that the alleged nuisance has caused physical damage to the property in order to prove an unreasonable and substantial interference in property rights and thus to make out its cause of action in nuisance (Oldham v Lawson (No 1) [1976] VR 654, at 658; Barbagallo v J & F Catelan Pty Ltd [1986] 1 Qd R 245, at 248; Bone and Anor. v Seale [1975] 1 All ER 787, at 794, see also Roberts v Rodier [2006] NSWSC 282, at [119]). 167 Indeed it was recognised by Harris J in Oldham v Lawson that, whilst nuisance is a wrong to property, even when there is no physical damage to property it may cause annoyance, inconvenience and discomfort to the occupier in his enjoyment of the property (Harris J there accepting (at 658) as stating the law in Australia statements to such effect by Scarman LJ in Bone, at p 794) (though I note that a failure to prove actual damage may result in only nominal damages being awarded). 168 In Barbagallo (at 248) McPherson J stated, with whom de Jersey J (as his Honour then was agreed) (citing Oldham v Lawson as authority for the following proposition): It need hardly be said that in this context actual damage is not to be treated as synonymous with physical damage. The rights of a landowner may be infringed, and his enjoyment of his property interfered with or diminished, even before his land subsides into the excavation made by his neighbour. If, acting reasonably, he vacates before it falls he will be entitled to recover consequential pecuniary losses, such as the cost of alternative accommodation. The tort of nuisance does not require as an element or ingredient in its proof the establishment of physical damage. 169 Thus I have not included as a separate issue for determination (in relation to the question as to whether there is liability for nuisance) the issue whether any loss or damage has been caused as a result of the alleged nuisance. I do however address that issue in the context of the negligence claim and in considering what relief would have been available had I been satisfied that the defendants were liable for past nuisance. Water flow cases 170 A number of cases have considered what amounts to nuisance in the situation where there is a flow of surface water from one property to a neighbouring property - water having been said to be a 'common enemy against which each man may defend himself'. (As noted by Windeyer J in Gartner v Kidman [1962] HCA 27; (1962) 108 CLR 12, the use of the term "common enemy" in this context seems to be derived from Lord Tenterden's judgment in R v Commissioners of Sewers for Pagham, Sussex [1828] EngR 680; (1828) 8 B & C 355, at 361 [1828] EngR 680; 108 ER 1075, at 1077, in relation to inroads of the sea and the expression has been repeated in cases dealing with the run off of surface waters and flood waters. 171 In Gartner, after reviewing various English, Australian and other common law authorities, Windeyer J (recognising (at [44]) that there had not been any clear or consistent view expressed in Australia) summarised the law concerning the flow of surface water from one piece of land onto the neighbouring land as set out below (from [48] – [49]) (there distinguishing between the flow of surface water and the flow of natural watercourses to which riparian rights attach; and distinguishing between waters naturally coming onto land and water artificially brought or concentrated thereon). His Honour said: The following propositions concerning surface waters relate only to water which came naturally upon the land from which it flows, as distinct from water artificially brought or concentrated there and allowed to escape as in Rylands v. Fletcher [1868] UKHL 1; (1868) LR 3 HL 330 . [pausing there, the flow of rainwater falling on the northern slope of the Alpine Nursery property would come within the principles here enunciated but the flow of water emanating from the storage facilities at dams 2 and 3 and then used for irrigation on the northern slope would seemingly not, being water artificially concentrated in those dams] With the above limitations in mind, the rights and obligations of the proprietors of contiguous closes, one on a higher level than the other, may be stated as follows: - The higher proprietor: He is not liable merely because surface water flows naturally from his land on to lower land. He may be liable if such water is caused to flow in a more concentrated form than it naturally would. It flows in a more concentrated form than it naturally would if, by the discernible work of man, the levels or conformations of land have been altered, and as a result the flow of surface water is increased at any particular point. If a more concentrated flow occurs simply as the result of the "natural" use of his land by the higher proprietor, he is, generally speaking, not liable. What is a natural use is a question to be determined reasonably having regard to all the circumstances, including the purposes for which the land is being used and the manner in which the flow of water was increased: as for example whether it is agricultural land drained in the ordinary course of agriculture , whether it is timbered land cleared for grazing, whether it is a mining tenement, or is used for buildings and so forth. (my emphasis) The proprietor of higher land is not liable for a more concentrated flow from his land if it is the result of work done outside his land by someone else, and for the doing of which he is not responsible, as for example by the paving and guttering of public roads by municipal authorities . (my emphasis) … The lower proprietor: He may recover damages from, or in appropriate cases obtain an injunction against, the proprietor of the higher land who is, for any of the reasons given above, liable to an action because he has concentrated or altered the natural flow. 172 In Bayliss v Lea (1960) 77 WN (NSW) 272, at first instance, Hardie J had quoted from the earlier decision of Jordan CJ in Broadbridge Little v Holroyd (1935) LGR (NSW) 81, where it was held that any alteration of land, whether by the erection of a bank or the making of a drain for the alteration of levels, which has the effect of increasing or concentrating surface water and causing it to flow on to land in such a way as to cause greater damage than if the land had been left unaltered, constitutes a nuisance. Hardie J also quoted from the decision of Roper CJ in Eq in Douglas v Swan (unreported, 12 December 1950, NSWSC) where his Honour found that in dealing with water that comes onto a property, whether naturally or from a neighbour's land, an occupier must not by any artificial work alter the natural conditions of the property so that the water proceeds from the property of a neighbour in greater volume or in a more concentrated flow that it naturally would, and by reason of this greater volume or more concentrated flow clauses damages to the neighbour's property; and that if damage is caused, then an injunction will be granted to prevent the neighbour from maintaining the particular works which cause the greater volume of water to flow onto the property of a neighbour or cause the particular concentration of water which does flow onto the property of the neighbour. though his Honour did not there make the qualification as to whether the alteration in the conformation of the land arose as a result of the natural use of the higher land, as had Windeyer J in Gartner . 173 Mr Philips relied upon Bennetts v Honroth [1959] SA SR 170 (that having been referred to with approval by the High Court in Elston v Dore, at 490) for the proposition that the defendants are liable where they have impeded the natural absorption or drainage of surface water by structures on the land (such as, as I apprehend the plaintiffs' position, the No 1 water retention dam, internal gravel roadways and the drainage system, including the placement of the impervious black sheeting on the northern slope of the property). (Complaint is also made, it seems, in relation to the eastern ridge or levy bank but this was not pleaded and cannot now be maintained.) 174 In relation to the drainage of surface water, in Gartner, Windeyer J observed (at [37]): If the water is found to be surface water, the question may arise as to the right of the person on whose property it is found to get rid of it. This raises the question of drainage, which is entirely distinct from any of the questions arising with respect to ponds and living streams. With the exception of a few states, the principal rules with respect to drainage of surface water from the land are uniform and well-settled. There is no right on the part of one landowner to drain the water from his land over that of his neighbour without the latter's consent. This rule prevents the gathering of water into a body and casting it onto the lower owner, or collecting it in artificial ditches for that purpose, or changing the course of drainage. There is one point, however, at which there is a sharp conflict between the courts of the respective states, and that is upon the question whether the natural depressions along which the water has been accustomed to flow must be kept open to permit the continued flow of the water, or any landowner may ignore and close them at his pleasure". (my emphasis) 175 Here, however, the water would naturally drain from the Alpine Nursery property onto the Quick Property and what is therefore complained of seems to be the alteration of the course of the drainage (and the collection and storage of water in the No 1 water retention dam from which it overflows onto the Quick Property). In this regard, Mr Kerr submits that there is a distinction to be drawn between the situation in Bayliss and the present, since there the decision to discharge water onto the plaintiff's land was made in effect to transfer the burden of the water artificially onto the plaintiff whereas in the present case water would always have flowed onto the Quick Property and the only difference may be the velocity or concentration with which that water now flows to the property. 176 I also note that in Melaleuca, the Court of Appeal said, at [23]: Discharge of water onto the appellant's land could be a nuisance if it was an unreasonable interference with the use and enjoyment of the land. But the nuisance would be the discharge onto the land, and each occasion on which there was a discharge would, if the respondent was liable, be a separate legal wrong. which requires an assessment to be made at each time the water is discharged onto the land as to whether there has been an unreasonable interference with the use and enjoyment of the land on that occasion. Factual issues 177 Having regard to the above principles, I turn then to the factual questions – namely has there been a substantial and unreasonable interference (by reference to the volume/velocity of water or the incidence of flooding or increase in percolation of subsurface water or water seepage), those being the only ways in which the nuisance claim is put, with the use and enjoyment by Mr and Mrs Quick of the Quick Property and, if so, has this resulted from the operations of the nursery or the changes in the conformation of the Alpine Nursery land in the manner which has been pleaded? (If so, then the next question is as to whether that is a natural or non- natural use of the land.) In determining the first question, I turn to the particular acts said to constitute the relevant interference. (a) Increase in velocity or flow of water – the water flow interference 178 Mr Kerr submitted that, at its highest, the plaintiffs' lay evidence merely demonstrated that water had flowed through the plaintiffs' property in varying quantities and velocities from time to time and that the plaintiffs' approach suffered from the logical fallacy (apparently well known to afficionados of political drama) as post hoc, ergo propter hoc ('after therefore because of it'). In other words, it is said that it does not follow, as a matter of logic, that merely because the deterioration of the southern or cattle paddock (to the state of a boggy marsh) occurred after the defendants commenced their redevelopment of the Alpine Nursery property the redevelopment must have caused the deterioration. 179 Mr Kerr (at T 135) was prepared to concede that such an inference might be able to be drawn if there were no other relevant change over the relevant period and there was evidence that there was a higher rate of water coming from the Alpine Nursery property (and from nowhere else) but pointed in this case to a number of other factors (such as the contribution of water from other sources to the flow arriving at the Ellis Road culvert and, in particular, the reconstruction of the Ellis Road culvert by the Council and the lack of ongoing maintenance of the paper road and southern paddock itself (the last of which being a factor that it is said has impeded the flow of water off the Quick Property and thus to it becoming waterlogged). 180 Mr Kerr submitted, and I agree, that ultimately the primary factual issue must be resolved principally by reference to the evidence of the hydrological experts retained by each of the parties. I accept this submission because it seems to me that the general observations and conclusions drawn by Mr and Mrs Quick must inevitably be coloured by the view they seem to have taken from the commencement of the development as to the adverse effect of that development and its unsuitability in a water catchment area. As to the evidence of Mr English (which there is no reason not to accept), it is limited to a general comparison based on photographic evidence shown to him of the current waterlogged state of the land. Mr English is not in a position to comment on the effect of a lack of maintenance on the property after he sold the property. 181 Both parties relied upon expert evidence in relation to the hydrological impact of the Alpine nursery operations. The experts conferred, pursuant to the standard direction for the giving of expert evidence, and were able to agree only on two issues. (The issues upon which the joint experts were unable to agree were addressed separately by each in further expert reports, Mr Dey in his report dated 2 July 2010 and Dr Bayley in his report dated 1 July 2010). (Although it was suggested at one stage that the Rules did not permit the adduction of evidence in relation to matters the subject of the joint experts' agreement, I was not taken to any authority to suggest that where there was ongoing disagreement between the experts that could not be explored in further evidence (assuming that did not trespass on the confidentiality of the matters discussed in the joint conference itself).) 182 Prior to the hearing, in the course of making preliminary rulings as to the various evidentiary objections to the affidavits which had been served by both parties, I ordered that the experts again confer with a view to the defendants' expert (Dr Bayley) providing the plaintiff's expert (Mr Dey) with material or information from which the latter could review or assess the results of the revised computer modelling which had been carried out by Dr Bayley following his consideration of Mr Dey's original criticisms. I did so because there had been some ongoing dispute between the experts (or between the parties' legal representatives) as to the provision of the relevant data files (which at least in part seemed to be referable to a misunderstanding between the experts) and because I thought this was the most expeditious way to ensure that the court would have the benefit of expert evidence on this issue. 183 Regrettably, that proved to be a rather unproductive exercise, largely it seems because Mr Dey apparently formed the view (at that late stage leading up to the hearing) that it would be better for him to start afresh and to carry out his own modelling (the results of which the plaintiffs then sought to tender midway through the third day of the hearing) rather than to comment on Dr Bayley's revised Model, the subject of the conference which I had directed should occur. Mr Kerr objected to such evidence being admitted (and noted that it consisted, amongst other things, of two pages of text not readily explicable on their face). I refused leave for Mr Dey's last minute modelling exercise (which was not in the form of a complete report and had not been verified by affidavit) to be put before the court (for the reasons given in a short ex tempore judgment on that day) although I made it clear that the content of that report could be used by Mr Dey in the course of him giving evidence concurrently with Dr Bayley, for example by way of commentary or criticism in respect of the MUSIC model already in evidence which had been prepared by Dr Bayley. 184 As the expert evidence features heavily in any assessment of the impact of the Alpine Nursery operations on the water flow to the Quick Property, I summarise my understanding of that evidence below. Respective experts 185 Mr Duncan Dey was called as an expert by Mr and Mrs Quick. Mr Dey is a civil and environmental engineer who (at the time of his resume, dated May 2009) was working with two different engineering firms in the design of stormwater systems, urban drainage analysis and design, flood estimation, creek hydraulic analysis and floodplain planning. Mr Dey holds a Bachelor of Civil Engineering from the University of New South Wales and a Certificate of Hydrology from the same university. Mr Dey listed his expertise as being in river studies, flood estimations, culvert/bridge design, water quality, stormwater design, on land sewage system design, sewage effluent management, water supply and ecological sustainability. 186 Issue was taken by the defendants with the fact that Mr Dey had not inspected the Alpine Nursery property prior to the view which was carried out on the first afternoon of the hearing. It was suggested that this was a matter which went adversely to Mr Dey's credit (in that he had been prepared to draw conclusions and put forward evidence, as an expert, to the court without having verified the assumptions on which that evidence was based). In this regard I note that Mr Dey's reports proceeded at least in a number of instances on the assumption that the observations contained in the lay affidavits relied upon by Mr and Mrs Quick were accurate. To the extent that those observations were contested or not otherwise supported by independent evidence (such as the observations by Mr Quick of a continuous trickle onto the Quick Property during dry weather - p 2 of Mr Dey's 27 October 2009 report; p 8 of his 18 May 2010 report – and the observations by Mr English as to the comparative state of the southern paddock), this means that the conclusions of Mr Dey based on those observations must be treated with caution. 187 Mr Dey himself appeared to accept that a more direct observation of matters on which expert evidence was to be given might be necessary: KERR: It's not possible to provide an expert opinion - and by "expert opinion" I mean one which complies with that required by the schedule to the Supreme Court rules - it's not possible to provide an expert opinion about the flow of water on to the Quicks' property without going to the Quicks' property and having a look at it so you can see what the property actually looks like; correct? WITNESS DEY: That sounds correct to me. KERR: And that's why you chose to do before purporting to express an opinion in relation to that which was occurring on the Quicks' property; correct? WITNESS DEY: Yes. KERR: Why then didn't you ever access Alpine's property to talk about the flow of water through it? WITNESS DEY: I had very good vision 188 While I do not consider that Mr Dey's apparently heavy reliance on the accuracy of instructions provided to him (though I note it was said that he had also had regard to the irrigation and drainage management plans) goes to his credit as such, it is a matter which I consider goes to the reliability of Mr Dey's conclusions (and as an indication of his tendency to make generalisations based on general observation of himself or others rather than on the basis of more scientific analysis). 189 For the defendants, Dr Mark Bayley was retained to give expert evidence regarding the flow and quality of water from the Alpine Nursery property. Dr Bayley is employed as a Senior Scientist and Operations Manager by Australian Wetlands Consulting Ltd. In the area of design and delivery of specialised wetland design projects, Dr Bayley conducts scientific investigations including design review, analysis of water quality data, preparation of strategies for water treatment and disposal (resume, affidavit 30 March 2010). Dr Bayley has a PhD from Griffith University (his thesis being on "Nutrient processing in stormwater treatment wetlands"), as well as a BA AppSc (Hons). 190 By way of a broad summary, Dr Bayley reached his conclusions largely on the basis of the results gleaned from the application of a computer model used in the analysis of water flows in different geographical locations (the MUSIC model) and approached the exercise of giving his expert evidence in what seemed to me to be a considered and thoughtful fashion. Where tested on the decisions he had taken in the application of that model he seemed to me to give logical and balanced answers (such as when issue was taken with the adoption of a 6 hourly rather than 6 minute mode for the model – where Dr Bayley appeared to accept that if used the 6 minute time step (as suggested in guidelines rather than as in the question which had been posed of him) the Model would produce something that would more closely reflect the possibilities as between a situation where there was consistent rainfall, where more water might perhaps soak into the soil) and a flash flood rainfall event – though in the former situation there might be more time to pump water out of the dam to avoid an overflow). Dr Bayley seems to have been prepared to concede where there were what he regarded as valid or at least reasonable criticisms of the manner in which he had configured the model (as evidenced by his preparation of the revised model to address some of the changes which Mr Dey in his report responding to the first model had suggested should be made). Dr Bayley, in my opinion, appeared to be ready and willing to engage in debate on the particular issues raised in respect of his modelling whereas Mr Dey did not appear able to engage directly in that exercise and took refuge in a more general criticism of the use of the model – instead favouring his more broad brush approach to the questions posed. 191 Mr Dey had a tendency to make broad generalisations without seeming to base those on any particular analysis of the evidence – but rather as a matter of his general observation or experience – or on the basis of calculations not put before the court (so, for example, in his 27 October 2009 report Mr Dey described the level of the increases in water flow from the Alpine Nursery land to the Quick Property as "significant" in both dry weather and storm events; though in the witness box he said that he had not carried out any comparative pre- and post- Alpine development calculations and while he said that he had carried out some calculations (which he could not produce) in relation to storm events they were based on predictive or 'design' (not historical) rainfall). 192 Mr Dey also (both during the view and during the giving of evidence concurrently with Dr Bayley) displayed a tendency to argue the plaintiffs' case (or perhaps simply to justify his original conclusions). He did not carry out or did not have available calculations to support his assertions and did not seem to have adopted as rigorous or objective an analysis as Dr Bayley. 193 In general, therefore, I regarded Dr Bayley as a more reliable witness and I had more confidence in his conclusions than those of Mr Dey. Joint Expert Report 194 The experts were asked to give their opinion, relevantly, as to whether there had been an increase in volume and velocity of water discharged post the Alpine Nursery development (as compared with the discharge pre the Alpine Nursery development) in three types of weather conditions – dry weather, intermediate rainfall events and storm or extreme rainfall events. They were also asked to express an opinion on the effect of the Alpine Nursery development on the subsurface water levels. 195 In a Joint Expert Report filed on 1 July 2010, the experts recorded their agreement on two issues: that in intermediate rainfall events there has been a reduction in the volume and velocity of water being discharged from the Alpine Nursery land after the Alpine Nursery development compared with the discharge beforehand; [the reason for the difference in opinion as between the experts as to the comparison between pre- and post- Alpine development water flows in dry and storm conditions, notwithstanding the position agreed between them as to the reduction in post-development water flows in intermediate events, seemingly being the result of a difference between the experts first as to the effect of irrigation in dry weather and secondly as to the extent of run off in storm events, as discussed below]; that the development and operation of the Alpine Nursery land has impeded the natural absorption or drainage of surface water flowing from the Alpine Nursery land and has thus reduced the recharge to the aquifer which supplies water to the bore installed on the Quick Property [by which I understand the experts to mean that there has been a reduction in the subsurface percolation of water on to the Quick Property not an increase in the percolation of subsurface water as seemed to be suggested in the pleadings], though the experts did not agree on the scale or extent of this impact. 196 The experts were in disagreement (at least at the time of their joint report) as to whether there had been a reduction or increase in the volume and velocity of water flowing from the Alpine Nursery land after the development in both dry weather conditions and in what were referred to as extreme rainfall events or storm events (Dr Bayley being of the opinion that there had been a reduction in both of those scenarios and Mr Dey being of the opinion that there has been an increase in both.) 197 I say that the experts were in disagreement as to the post-Alpine Nursery development water flows in both dry and storm conditions at the time at which their joint report was prepared because (to my surprise, having regard to that report), when the expert evidence was given concurrently in court, Mr Dey (who said that he had only made calculations which applied to the storm event case, not the dry case – T 208.36; and that those calculations were not comparative calculations pre- and post- Alpine but were calculations based on predictive, not historical, rainfalls ("design rainfalls") to make an hypothetical assessment of how much water could run off the property in certain time periods and then had equated that to the rainfall that would represent – T207.36-50), when referring to p132 of the Court Book and the reference to his 12 hour storm example, explained this aspect of his report by saying that: …I can explain what I'm saying here, is that when you get to extreme, rare events, and even the 1 in 1 year frequency is reasonably rare, there isn't much difference between the run-off from pre and post areas like that . Most water runs off fairly independently of the nature of the surface in an extreme event " (T 209.1). (my emphasis) 198 Whether an event is classified as 'extreme' is a function not of the frequency with which such a rainfall event may occur but as to the amount of rain that will fall in such an event. (Nevertheless, in terms of frequency, Mr Dey regarded a one in one year flood as still being a relatively rare event.) 199 Mr Dey confirmed, when clarification was sought not only by Mr Kerr but also (since I wished to be sure that I had understood his evidence correctly in this regard) by myself, that in extreme events (whether a 1 in 1 year flood or a 1 in 50 year flood) the run-off from the property would not be much different pre- or post- the Alpine Nursery development (see T 209.11-15;25; 37; 50). He then suggested that the "little difference" would be in the order of 10% (T 210.6) (though that differential was difficult to square with his more general evidence that the run-off co-efficient in extreme events was over 90% (T 209.40)). 200 Given the significance of the concession made by Mr Dey as to the position in more than intermediate wet weather, I set out the exchange which occurred during the giving of evidence jointly by the experts (from T 209.25): WITNESS DEY: Yes, that in extreme events they're not very different. That also was the endeavour of my calculation in that paragraph. HER HONOUR: Are you telling me that whatever property one was looking at, there's not much difference in run-off between a 1 in 1 year or a 1 in 50 year event or are you telling me - which in fairness I think this is what you have told me - that in relation to the Alpine property there's not much difference in the run-off in an extreme rain event, between the run-off there would have been pre the development, and the run-off that there is post the development, in an extreme rainfall event, whether that be 1 in 1 frequency or 1 in 50 year frequency? WITNESS DEY: Yes, the latter is correct, at the 1 in 50 year frequency I haven't examined it in detail closely for the 1 in 1 year frequency but certainly in a 1 in 50 year storm, these storm events tend to have a run-off co-efficient of over 90 per cent. In other words, it would be difficult to distinguish a difference in an event of that nature but I'm naming extreme events and I could remind the Court that an extreme event of this nature is one in which you can't even drive your car. HER HONOUR: As I read this, and you will tell me if I'm reading it incorrectly, your report says that, "90 per cent run-off" - which I think you're now telling me a 90 per cent run-off is what you get in an extreme event - "This is in ... 1 year frequency". WITNESS DEY: Yes. HER HONOUR: What I read that to be saying is that in an event of about a 1 in 1 year frequency, I could expect a 90 per cent run-off or very little difference in the position in pre and post development? WITNESS DEY: Yes, that's correct. The little difference would be the 10 per cent difference between 90 per cent and 100 per cent . (my emphasis) 201 To the extent that Mr Dey suggested in the witness box that there might be a 10% difference pre- and post- the Alpine Nursery development in the water run-off in extreme events (if that is what he was indeed suggesting), my impression of the manner in which he gave that evidence was that it had the flavour of a very rough estimate plucked from the air. Certainly, no rationale was put forward for it. It seems to me to be based on an assumption that post- the Alpine Nursery development (but not prior to that development) the run-off co-efficient in extreme events would be 100% but no basis was put forward to suggest that that would be the case (and that ignores any water that would be caught up in the drainage system even in an extreme rainfall event unless it is assumed that all such rainfall would overflow from the dam). I am not persuaded that I should rely on this 10% estimate of the differential and in any event there was nothing to suggest that a 10% differential would be material. Mr Dey himself was dismissive of the difference when he said (and confirmed) that there would not be much difference in the run-off in extreme weather between the position pre and post the Alpine Nursery development. 202 As I understand Mr Dey's evidence in the witness box, while he does not expressly agree with the conclusion reached by Dr Bayley (that in storm events there has been or will be a reduction in the water flow from the Alpine Nursery property post the Alpine Nursery development) what he nevertheless now does not (or perhaps I should say does no longer) assert is a conclusion that there is a substantial or material increase in the water flow in that scenario. It seems to me that this is fatal to the suggestion that there has been an unreasonable interference in the enjoyment of the Quick Property by reference to the discharge of water in extreme events (and since that is when the dam is most likely to overtop, there can on this reasoning be no unreasonable interference by reference to the incidence of flooding, which on Mr Dey's evidence must be likely to occur on those occasions irrespective of any overflow from the No 1 water retention dam). 203 Thus the only event in which it seems there is a live dispute between the experts (as to the pre-and post- discharge of water from the Alpine Nursery property to the Quick Property) is in dry weather conditions and to describe that as a 'flow' seems to me to be a misnomer. What occurs in dry weather, even on the plaintiffs' evidence, is no more than a trickle, constant though that trickle might be. (For the reasons set out below I cannot accept that even a constant dry weather trickle of water, assuming that it does come from the Alpine Nursery development, amounts to an unreasonable interference with the use and enjoyment of the Quick Property.) Summary of expert reports 204 The questions each expert was asked to address in his initial report were somewhat differently expressed but, in broad terms, what the experts were asked to consider were issues relating to the flow of water onto the Quick property, the percolation of water through the subsurface watertable and the quality of the water. (Mr Dey was also asked to suggest remedial measures and to comment on the defendants' September 2008 Water Management Plan and its effectiveness, particularly with reference to "water quality management", "nutrient management" and "water testing procedure" in the management monitoring and control of blue-green algae contamination in any water flowing on to the Quick Property from the Alpine Nursery property and the levels of nutrients and chemicals in any water flowing on to the Quick Property from the Alpine Nursery property.) 205 Mr Dey concludes in his reports that the development of the Alpine Nursery land has resulted in the following impacts: (i) increased volume (which, contrary to his later evidence in court in relation to wet weather conditions, he described as 'significant') and frequency of surface water discharge from the Alpine Nursery to the Quick Property in both dry weather conditions and in very wet weather conditions (as noted above, he resiled from that proposition in relation to the volume of surface water run off in storm or very wet conditions when he gave evidence that there would not be much difference in those events between pre- and post – Alpine development); (ii) decreased regional watertable levels; and (iii) a deterioration in the quality of water entering the Quick Property from the Alpine Nursery land (a conclusion which he seems to base solely on Mr Quick's observations as to the use of chemicals on the Alpine Nursery property – see p 10 of his 27 October 2009 report). 206 In contrast, Dr Bayley, was of the opinion that: (i) there has been no increase in the volume and velocity of surface water discharged from the Alpine Nursery land following the development; (ii) there has been no regional lowering of the watertable as a result of the development of the Alpine Nursery land; and (iii) there has been no increase (compared with past land uses) in the export of nutrients and sediment from the Alpine Nursery land; (I note that the conclusion that the nutrient content of run-off from a potato farm would be greater than that from the nursery is based on the assumption that the nutrient content of the soil on the nursery land would be greatest on the production beds and that water from those is drained into and retained in the No 1 water retention dam, though this does not seem to take into account what happens when there is an overflow from that dam as the water in that dam still contains the nutrients in question). 207 It does not appear to be disputed that a proportion of the surface water which would otherwise have flowed off the Alpine Nursery land and through the Ellis Road culvert onto the Quick Property is instead channelled into the No 1 water retention dam (that being the proportion of water drained from the production beds and any water otherwise falling directly into the dam) and that, while contained in the dam, it will retain whatever nutrients were in it. Nor is it disputed that in extreme rainfall events the dam overflows such that a portion of the water in the dam spills over the spillway and into the riparian filter and through to the Ellis Road culvert, converging as it goes with any water running from the east of the property along the grass swale. 208 The water retained in the No 1 water retention dam is not treated in that dam for the removal of nutrients (though it is treated in situ as necessary for the control of certain types of algae). Treatment of the water from the No 1 water retention dam takes place uphill (the drainage system allowing water to be pumped between the respective dams). However, in considering the question of nutrients in the water, there is a lack of evidence as to what nutrients would have been expected to be in water flowing off the Alpine Nursery slopes while that area was cultivated for potato farming. Mr Dey's report 209 Mr Dey attributed the conclusion set out in paragraph [175(i)] above (in his initial report of 27 October 2009 pp 2, 7, 8, 9 and 19) to two factors: the use of the black plastic sheeting (which he says increases the runoff from the relevant areas) and the irrigation regime (which he says, based on Mr Quick's observations, has had the effect that even in dry times there is a "constant trickle" of water from the Alpine Nursery land to the Quick Property). The nub of this conclusion seems to be that less rainfall penetrates the surface of the property covered in black plastic (although it is not apparent that he has taken into account any amount of rainfall absorption in the pots which stand on top of the production beds themselves) and that his has increased the 'run-off co-efficient' so that less water soaks into the soil – see p 9 of his report. In his report of 27 October 2009 Mr Dey did not appear to attribute any increase in the water flow to the channelling effect of the ridge or levy bank along the eastern side of the property. 210 Mr Dey's initial conclusion in relation to the increase in water flow in storm events was based largely on lay observations (see part 1.5 of his 27 October 2009 report, referring to the reports by Mr Quick and Mr English to the effect that the southern paddock had been much drier before the Alpine Nursery activities began, including statements in Mr English's affidavit to the effect that the dam in the southern paddock would not hold water and that after rain the water would drain away from the hole within a few days and the statement by Mr Quick to the effect that once he had been able to mow the cattle dam area with a ride-on mower but that now the area is so consistently wet that he is unable to mow the area) and the DVD video footage specified on p 8 of Mr Dey's 27 October 2009 report. 211 Mr Dey expressed the opinion that such evidence indicated that there are generally 'several overflows' per year from the No 1 water retention dam and that the storm run-off from the areas covered with black plastic could be 'severe'. (When pressed in cross-examination, Mr Dey maintained that he was able to form a view as to the volume or velocity of water flow by reviewing the video footage, although conceding that in his professional role as an hydrological consultant he would generally inspect the flood area before expressing such an opinion). Mr Dey further supported that conclusion by reference to his "knowledge of the hydrologic cycle" (at p 3). 212 Even if a view can confidently be formed as to the velocity and volume of water flow (as opposed to the course of the water flow) from the video footage (and I note that Dr Bayley said that it was not possible to do so) it is difficult to see how any real comparison can be made on the basis of video footage of this kind since there is no video footage of pre-Alpine development run off. 213 As a non-hydrological expert having viewed the DVD footage which was tendered as part of the plaintiffs' case, I was unable to make any assessment solely by reference to that video footage as to the severity of the storm conditions there depicted (such as whether the relevant events were taking place in intermediate or extreme conditions - although by reference to the affidavit evidence it might be possible to do so by matching the date of the footage to the rainfall events to which Mr Quick has deposed) nor as to the comparative absorption in those conditions had the production beds not been covered in black plastic (and I was cautioned against so doing). That said, nothing seems to turn on this given Mr Dey's evidence in the witness box that there would be little difference in the runoff coefficient for extreme events and his agreement that there has been a reduction in intermediate events. 214 The difficulty I have in general with Mr Dey's evidence is that it appears he has to a large extent simply assumed that the reason for any difference in the perception by Mr Quick and Mr English of the changes in the level of water in the paddock must be the activity on the Alpine Nursery without having taken into consideration other factors that might have contributed to the retention of water in the southern paddock (such as the condition of the adjacent paper road, the hydraulic barriers arising from the condition of the southern paddock itself, namely the clumps of grass and weeds in the paddock itself and the foliage and debris along the boundary fence) or to the velocity or concentration of the flow (such as the widening of the Ellis Road culvert). 215 In relation to the issue of hydraulic barriers, it arose as follows during the course of the concurrent evidence (from T 252.21); KERR: Gentlemen, you were both on the view. Not all of us got to trample all over what could be described as the boggy paddock but it was evident that there was water throughout parts of that paddock. The water in some parts was at a depth such that gumboots were needed to walk through it, regular shoes couldn't be used to walk through it without them being inundated with water. It certainly didn't have the appearance of a lawn in the way that some of the photos some years ago show that southwestern paddock. Can either of you, or both of you, comment on why you say that paddock now has the boggy appearance, at least in some large parts of it? I take it the Court thinks that's an appropriate question? HER HONOUR: I do. WITNESS BAYLEY: Who would you like to respond first? KERR: Up to her Honour. HER HONOUR: Dr Bayley, I think you may respond first. WITNESS BAYLEY: Thank you, your Honour. I'll try and make this relatively simple and brief. The behaviour of water in the paddock which we walked through on Monday, regardless of how water is delivered to that paddock is controlled by how it leaves the paddock, so water gets into the paddock by rainfall directly on top of it or entering through the culvert or coming in through the underground aquifer, so there's three ways it can get in there and how - the length of time it stays in there and the height is contained within there, like how high it goes up our gumboots, is dictated or controlled by how it leaves the property. Now, I'm just going to draw a simple analogy, if you will let me - maybe, first of all, I'll step back a minute, I think it's a lot wetter and deeper now than when the previous owner had owned it because there's a lot of hydraulic barriers or hydraulic walls to the flow and movement of water on to the property. By hydraulic barriers and walls I'm referring to the vegetation, both within the plaintiffs' paddock and the paper road or the drainage road that is directly abutting the paddock. If you just picture the surface, a plant and the grass, they're quite high, and all of those little walls, they're very small but if you add them all together it becomes quite a big wall, especially if you add on the fact that there is a lot of dead debris on the fence line, a lot of hydraulic barriers preventing movement of water from that property. To draw an analogy about that hydraulic barrier and the movement of water from that property, regardless of how it gets there is - say you're having a shower, you've had long hair at some stage of your life, I presume - I have - and you turn the taps on at 50 per cent, the shower - you're washing yourself, water is flowing through the plug hole quite easily, you have got a big mop of hair and you start to wash it and the hair starts to fall out and it starts to accumulate around the plug hole, which is how water gets out of the shower. As you wash your hair more hair falls out, it accumulates in the plug hole, water is finding it hard to get out, you haven't actually turned off the shower and water is pooling around your feet. The only way is to get the hair out in order to remove the hydraulic barrier and get the water moving. I think the Quicks' paddock is wetter now because it's not managed in the same way as what it was and the drainage line, or the unmade road, is not managed or maintained to the level of what it was previously. And I keep going back to the underlying principle, regardless of how water gets into that paddock, it's behaviour, its depth, the time it spends in there is dictated by how it leaves the paddock. It's like the plug in the bath. HER HONOUR: So that if the clumps of foliage or weeds and the like that were in the paddock, if they were removed it will drain more quickly? WITNESS BAYLEY: It would drain more quickly until the next barrier, which would possibly be the fence, and the next one, which might be 1 centimetre away, all the vegetation and the growth on the paper road. In drainage lines like the one we saw, where it's relatively flat and uniform in size, it doesn't take much to raise the level of water. It could be a log fall over, it could be a thick mat of vegetation, it's very intolerant to blockages and fallen logs and various other hydraulic barriers that I would expect to see in a natural drainage line. HER HONOUR: And the speed that the water comes through, will that make it easier or harder for it to move off quickly? WITNESS BAYLEY: The faster it comes the quicker it moves through, so the more force it has to push over those barriers, unless of course it's come down with sticks and stones and logs and silt. HER HONOUR: And silt? WITNESS BAYLEY: And silt. HER HONOUR: And silt will create an hydraulic barrier? WITNESS BAYLEY: As it builds up, yes, it will, it definitely will. KERR: Dr Bayley, were you present in Court when I asked some questions via video link of Mr English? WITNESS BAYLEY: I was. KERR: Did you hear what he said in relation to works that he had undertaken on what we call the paper road and what he called the unmade road? WITNESS BAYLEY: I was, yes, I did hear that. KERR: Do you have anything to say relevant to that which you have just indicated to her Honour as a consequence of hearing that evidence from him? WITNESS BAYLEY: The way I heard the previous owner was he actively maintained his parcel of land as well as the drainage line. KERR: He says he removed all the lantana from the paper road. Would the existence of clumps of lantana have any impact in a positive or negative sense in relation to the hydraulic barriers that you're referring to? WITNESS BAYLEY: Yes, that would, over time, be a, if it wasn't removed, be a hydraulic barrier. For me, lantana is a straggly kind of plant that grows like that. The first lot might not but-- KERR: What you say "it grows like that" you mean it grows in all sorts of directions? WITNESS BAYLEY: Yes, it's a little bit crazy in its growth. It's not very thick but it's got lots of little stems. The first flood, flood number 1 comes through, the first part might move threw okay, you would get deposits of sticks, silt and plants, and the next flood comes through and builds on top of that and on top of that and on top of that and a hydraulic barrier or wall has been created from the build-up of debris and is getting more and more and more and backing the water up more and more and more. KERR: In relation to the evidence you've just given, does the existence or the height at which the water table exists have anything to do with that which you've just indicated? WITNESS BAYLEY: It would have a strong impact. 216 (I note, however, that when the issue of hydraulic barriers was raised during the concurrent expert evidence, Mr Dey was dismissive of this as a factor.) 217 Although Mr Philips criticised Dr Bayley's evidence as to hydraulic barriers (as an explanation of the state of the southern paddock) on the basis that it had only been given in the witness box and not in the affidavits or experts reports, this was a matter raised during the view (and a matter of observation and common sense on the view) and Mr Dey appeared readily able to deal with it (though dismissive of it). I accept that it was to a degree an exercise in speculation to say that this was the cause of the waterlogged paddock but it certainly appears likely to have been a cause and it highlighted the uncertainty as to the operative cause of the problem and thus weakened any inference that might otherwise have been drawn that this could only have been the result of the nursery operations. 218 Neither expert has measured the actual changes in water flow (which I understand would have been an onerous and expensive task). However, whereas Dr Bayley has attempted to measure the change through the use of computer modelling, Mr Dey's opinion, as expressed in his report, seems to be based solely on second-hand observations (for example the observation that the Ellis Rd culvert trickles continuously even in dry weather) and his general hydrological experience (which was unable to be tested in any meaningful way given the generality with which it was expressed). 219 In relation to the change of water flow in dry weather events, which ultimately is the main area in which he differed from Dr Bayley, Mr Dey expressed the opinion that daily watering and the black plastic sheeting had increased the run-off of water from the property as evidenced from the 'continuous trickle' observed (by Mr Quick) 'running' through the Ellis Road culvert. Mr Dey says that the use of irrigation keeps the soil constantly saturated and that this, coupled with the use of black plastic, increases the run-off coefficient. However, this reasoning does not take account the fact that water falling onto the plant production area (which is the area lined with black plastic) from the irrigation system is channelled by the land's drainage system into the retention ponds, not into the Ellis Road culvert. Other than situations in which the sprinkler spray falls onto the internal roads (and which ultimately drain into the Ellis Road culvert), (estimated by Mr Dey in the witness box at 25%) the irrigation should not therefore be responsible for the water arriving at the culvert in dry weather. 220 Also affecting the flow of the water off the Alpine Nursery land, is said to be the construction of swales (or diversion banks). (As noted earlier, this is not identified as a basis for complaint in the pleading.) Mr Dey explains that swales concentrate the stormwater and move water off the catchment faster than would occur in natural or previous conditions, and also remove the opportunity for the water to soak into the Alpine land, thereby increasing the amount of water running off the land and reducing the amount of water soaking into the water table. Again, this relates to the position during intermediate or extreme (not dry) rainfall events. 221 In particular, at page 5 of Mr Dey's 18 May 2010 report, he explained that the levy or gully constructed along the eastern boundary of the Alpine property has had the effect of preventing water flowing from the farms to the east of the Alpine Nursery from flowing onto and down in a north westerly direction across the Alpine Nursery property towards the Ellis Road culvert and that, instead, the water flows straight down the eastern boundary of the Alpine Nursery property in a northerly direction and then flows either across the road or is channelled in to a series of swales and through the gully running along the northern boundary of the property parallel with Ellis Road through to the Ellis Road culvert. 222 It was clear from the DVD footage that I watched that in at least some rainfall events water does now flow in the direction described by Mr Dey (and, although Mr Kerr took issue with the drawing of any adverse inference from the DVD footage, he did I think concede that I could make the observation above as to the course of the water flow) though, as I indicated during submissions, it did not seem to me that much turned on this as there was no evidence as to effect of a more concentrated flow arriving at the Ellis Road culvert. Mr Rolfe, moreover (as noted earlier), gave evidence that prior to the construction of the levy bank, water from the eastern farms would flow down the Alpine Nursery driveway (which had been in existence well before the development of the Alpine Nursery land) and that it was likely to flow more quickly down that driveway than it now does down the grassed swale parallel to the levy bank. If so, there is no relevant adverse change in this regard. Dr Bayley 223 Dr Bayley's expert report dated 30 March 2010, in summary, concluded that there had not been an increase in surface water flows to the Quick Property following development of the Alpine Nursery (his computer modelling indicating instead a decrease in water flow); that there had not been a significant increase in nitrogen, phosphorus or sediment from the Quick Property following development of the Alpine Nursery; and that there was insufficient information available on the construction of the bore on the Quick Property conclusively to determine that any lack of groundwater flow is a result of development of the Alpine Nursery. (Dr Bayley expressed the opinion that there were many reasons why the ground water bore installed on the Quick Property may not have produced water which do not relate to the development of the Alpine Nursery land.) 224 Dr Bayley concluded that pollutant and hydrologic modelling (using what is referred to as the MUSIC Model) indicated a net reduction in stormwater run-off from the property, and an improvement in water quality compared to the pre-development condition as a potato farm. He concluded that there was no evidence produced to support the claim that the development had resulted in a decrease in regional water table levels, most importantly due to the lack of any data demonstrating groundwater availability prior to the Alpine Nursery development from which such a comparative assessment could be made. MUSIC Model 225 Dr Bayley's conclusions as to the reduction in surface run-off from the Alpine Nursery land are based upon test results from computer modelling, specifically from the results of modelling produced by the Model for Urban Stormwater Improvement Conceptualisation (referred to in a shorthand way as the MUSIC Model). (Although the data files were tendered in evidence, there was no suggestion that I should attempt to make use of them and I indicated that unless taken to them I did not propose to do so.) I Dr Bayley's evidence was that this model is one of the two main ways of determining the impact of development on a catchment area. It does so by simulating the flow of water and pollution from catchments. Its use is said to be a matter of standard industry practice. Dr Bayley explained that this method is preferred over the alternative method (the practice of taking detailed measurements in a catchment area during a range of rainfall times) for a number of reasons, primarily being the higher cost of the latter method, the difficulty of finding experts who are skilled in the area to take such detailed measurements and the unavailability of data prior to development of the land (which means that a comparison could not be made on this basis in any event). (Dr Bayley did not suggest that the method of calculation apparently adopted by Mr Dey (namely the use of predictive or 'design' rainfalls to assess the likely water flow in a particular rainfall event) was one of the standard industry methods to determine water flow.) 226 As explained by Dr Bayley, the MUSIC Model relies upon input data derived from monitoring pollutant and nutrient loads from many urban catchments including some undeveloped catchments labelled 'rural'; and on monitoring input rates as against output rates (that is the rates of water flow and of the flow of nutrients and pollutants) which occur as water flowing through various types of nodes (which can be treatment devices such as swales, culverts, wetlands, bio-retention filters and dams etc) which can be conceptualised by the MUSIC Model. 227 As I understand it, to use the MUSIC Model it must first be customised to take into account the specific characteristics of the subject catchment area. Once that is done, data representing the rainfall over the catchment over a period of time, is run through the Model to produce statistics such as the sort relied upon by Dr Bayley which indicate the amount of water flowing out of the catchment and, by reference to the rate of performance for the removal of nutrients from the water, the amount of nutrients contained in the water exiting the catchment (for example, see annexure D of Dr Bayley's 1 July 2010 report). 228 The accuracy and reliability of the results from the MUSIC Model, and thus the weight that can be afforded to Dr Bayley's opinion (given his reliance upon the MUSIC test results), depends upon the ability of the model to accommodate the individual characteristics of the catchment in question, such as the surface types within the catchment and the area of the respective surface types (for example how much of the Alpine Property is lined with the black plastic sheeting compared with the area comprised by gravel roadways). 229 Much of Mr Dey's report dated 18 May 2010 is concerned with criticisms as to the form of the Model used (and he was anxious in the witness box to make clear his view that this was not the appropriate Model to use) and suggestions as to changes that should be made in order to render the model one that in his view would more accurately reflect the catchment area. Ironically, then, when Dr Bayley did adapt the Model to take into account some of Mr Dey's suggested changes, that too was the subject of criticism by Mr Dey. Criticisms of MUSIC Model used in Dr Bayley's first report 230 Mr Dey in his report dated 18 May 2010, listed a number of criticisms in relation to the use and configuration of the MUSIC Model as a tool for determining the impact that the development on the Alpine land has had on the quantity and quality of water flows from the Alpine property, including: (i) that, as the statistics for the Model are generated from annual data averaged for the period over which the Model is run, the results will not describe fluctuations in performance in events such as dry weather or very wet weather. (Mr Dey was of the opinion that the Model did not have the recognised capability to calculate storm behaviour, though he did not suggest what industry methods superior to this would be available (and, in any event, ultimately Mr Dey did not suggest there was much difference in the outcome in respect of storm events – which suggests that Mr Dey was simply offering academic or theoretical criticism of the Model, not as to its result in this instance). In this regard, Mr Dey pointed to the caution noted in the provision of the software itself that not all aspects of stormwater management were incorporated into the Model. (ii) that the Model was not appropriate for nursery developments, on the basis that the performance of various stormwater treatment devices (such as swales) had been modelled on data recorded in urban (not nursery) situations (though it was not suggested how those would relevantly differ, again suggesting that this was an academic not substantive criticism). (iii) that the Model is unable to accommodate water flows that are "imported" into the catchment other than from rainfall (ie from the use of water originating outside the catchment, such as the water in dams 2 and 3, for irrigation within the catchment). (Thus Mr Dey says that the MUSIC Model results underestimate the extent to which and frequency with which No 1 water retention dam will overflow and thus underestimate the amount of water flowing into the Ellis Road culvert in those situations). (iv) that there had been incorrect specification in the Model of certain areas referred to in Dr Bayley's report (and the suggestion that there had been typographical errors in some of the tables outlining the data inputs for the MUSIC model provided by Dr Bayley, specifically concerning the amount of runoff from adjacent farms and the airspace available in the No 1 water retention dam). 231 There seems no doubt that the usefulness of the MUSIC Model depends on the assumptions which are used in what is referred to as the 'calibration' or the Model (or what I referred to above as the configuration of the Model). The cautionary notes provided with the software for users (a copy of which are annexed to Mr Dey's 18 May 2010 report) include the following: First, MUSIC is not a detailed design tool; it does not contain the algorithms necessary for detailed sizing of structural stormwater quantity and/or quality facilities. MUSIC should be viewed as a conceptual design tool. Second, MUSIC should only be one of several tools used in Water Sensitive Urban Design. This is because factors other than stormwater quality (eg land and soil characteristics, amenity, passive recreation, and landscape design) are also important. Nor does MUSIC incorporate all aspects of stormwater management that decision makers must consider. Hydraulic analysis for stormwater drainage, life-cycle cost analysis, indicators of ecosystem health, and the integration of urban stormwater management facilities into the urban landscape are currently omitted from the model. … The third caution relates to (a) the assumptions inherent in the design of MUSIC, and (b) the need for calibration. There are a number of assumptions in the MUSIC model. For example, the rational used for selecting default parameters assumes certain conditions are present. User MUST read the MUSIC User Manual, including its appendices, to understand these assumptions, and the impact that breaches of them may have. Users should also attempt to calibrate models developed in MUSIC, wherever possible. Calibration should be undertaken for the rainfall runoff model, using local flow data wherever possible. Similarly, wherever reliable data on expected pollutant concentrates, or treatment performance are available, the should be used to calibrate the MUSIC model. Simulations developed without calibrations should be reported with appropriate caveats. 232 Mr Dey criticised Dr Bayley's report for its failure to mention calibration to local data or observations (although he conceded that there was reference to rainfall data for a near station); for the use of generalised soil descriptors for the land (on the basis that these were for a much larger area than the present catchment and for the lack of specific soil tests or specific flow data collected for the waterways modelled (although no such tests seem to have been undertaken by Mr Dey himself); for the accuracy of the catchment area (a matter which Dr Bayley corrected in his second report); for what he regarded as an underestimate of the amount of the catchment area that is impervious (though Mr Dey himself seems to have largely assumed the area covered by the black plastic sheeting); and for the alleged overestimation of the runoff coefficient assigned to areas such as the internal roadways. 233 Mr Dey contended that the results of the MUSIC Model analysis underestimated the amount of run-off post Alpine development (although given the fact that he says that in storm events the run-off is 90% in any event, this should not produce a significant distortion – as Mr Dey in the witness box seemed to concede). 234 Mr Dey also criticised the assumptions made in the Model as to the rate of performance of certain swales in the removal of nutrients, which I refer to below. 235 Mr Dey criticised Dr Bayley for overestimating the amount of water used from the No 1 water retention dam as compared to the provision referred to in the Irrigation and Drainage Management Plan (which Mr Dey said had the result of over-estimating the airspace available in that dam and reducing the estimated frequency of overflow and the overall flow of water from the dam). 236 Overall, the weight of Mr Dey's criticisms seem to me to go to the extent to which the MUSIC Model does not account for additional sources of water (such as that water being pumped from the No 2 and 3 water retention dams and from the ground water sources), though he also places reliance on the alleged underestimation of the amount of available space in dam 1 and the degree to which that dam overflows, and overestimation of the amount of run-off pre Alpine Nursery development and of the nutrient removal performance of swales or other treatment nodes. The bottom line, however, is that despite all this criticism of the report, ultimately Mr Dey's conclusion as to the effect of the development on the amount of water flowing onto the Quick Property during rainfall events (leaving aside the question of the quality of that water) is broadly the same as that of Dr Bayley. Adjustments made to MUSIC Model 237 In response to some of Mr Dey's criticisms, Dr Bayley made some adjustments to the MUSIC model so as to simulate the area of the catchment area as agreed between the two experts, as outlined by Dr Bayley in his affidavit of 13 July 2010, paragraph 15 and his report dated 1 July 2010. (Dr Bayley also noted in his report (dated 1 July 2010), presumably in response to the criticism as to the use of the MUSIC Model as a tool for the exercise being carried out in respect of this particular property, that the MUSIC Model adopted for his report was consistent with the Gold Coast City Council's guidelines, which had been adopted by Ballina Shire Council, and which had also been approved by the Northern Rivers Regional Councils.) 238 Specifically, Dr Bayley made the following changes to accommodate some of Mr Dey's criticisms (as referred to at p 3 of his 1 July 2010 report): (i) changing the size of the "West Farm Catchment" to the size suggested by Mr Dey in paragraph 3.1 of his 18 May 2010 report; (ii) changing the representation of the swales as per Mr Dey's suggestion in paragraph 3.3 of his 18 May 2010 report; (iii) amending the performance of "Pond 1 node" as suggested by Mr Dey in paragraph 3.7 of his 18 May 2010 report; and (iv) calibrating the MUSIC Model to adopt the run-off coefficients to those asserted by Mr Dey to be correct in paragraph 3.10 of his 18 May 2010 report, and pages 2 and 7 of his 27 October 2009 report. 239 The results from the modified MUSIC Model are detailed by Dr Bayley in his second report dated 1 July 2010 (Annexure D), the report itself being annexed to his affidavit dated 13 July 2010. In summary, those results did not alter Dr Bayley's previously expressed opinions as to the changes in the flow of water and nutrients from the Alpine Nursery property. Relevantly, Dr Bayley confirmed in his report dated 1 July 2010, his opinion that there was a reduction in flows of water in all of dry, intermediate and storm events post Alpine development. 240 One limitation of the MUSIC Model acknowledged by Dr Bayley in this report was that it did not allow for the replication of the irrigation regime used on the Alpine Nursery. He accepts that it does not allow for the assessment of the potential impact of irrigation water running off the property (p5 of 1 July 2010 Report). 241 To the extent that the MUSIC Model is unable to address the impact of the additional source of water represented by any water pumped from the No 2 or 3 dams (and assuming that any such water had not originated from the No 1 dam), say, for example, in times of needing additional water for irrigation) then it might seem that this would impact on the reliability of the MUSIC Model results (as Mr Dey says it does). However, the frequency of overflows from No 1 water retention dam must logically depend on the amount of the surface water run-off from rain falling within the catchment and the capacity of the dam to store that portion of the run-off which is drained through to it from the production beds. (Any overflow from the No 2 and 3 dams is irrelevant in this exercise because it will overflow to the Youngman's Creek catchment area.) 242 Thus the question posed of the experts in concurrent session by Mr Kerr as to whether an assessment had been made as to the storage capacity of the soli pre the Alpine Nursery development and the storage capacity of the dam post the development. It appeared that only Dr Bayley had made such an assessment and his conclusion (T 274.32) was that the storage capacity of the No 1 water retention dam far exceeded the storage capacity of the soil before the Alpine Nursery development. 243 Given that Mr Dey now accepts that in extreme weather events (which will be the most likely times of overflow) the water run-off is not much different than that in the pre-Alpine development scenario (because of the similar run-off coefficient of 90% pre and post development), arguably what will overflow from the No 1 water retention dam in those circumstances is no more than what would have run off the surface of the land in the pre-Alpine development (since it is only that which cannot be collected in the dam on top of the existing rainfall which should overflow). 244 Dr Bayley affirmed his view that the volume and velocity of water discharged from the Alpine Nursery had decreased (notwithstanding his acknowledgment that the MUSIC Model did not take into account the additional water source represented by irrigation from dams No 2 and 3) on the basis that a large percentage of the run-off that occurs following rainfall events within the Alpine Nursery flows into the dams and that those dams have capacity (to the extent of the amount of headspace kept available to absorb and retain run-off from rainfall events) which will reduce the velocity and volume of water being discharged from the Alpine property during storm events. Dr Bayley was instructed (and Mr Wilson gave evidence to the effect) that when Alpine Nursery staff anticipate a rainfall event they activate the pump so that water is pumped out of the No 1 water retention dam to create additional headspace in that dam and provide a greater capacity to retain and prevent a larger amount of water from reaching Mr and Mrs Quick's property. 245 It is only in heavy rainfall (or perhaps a flash flood) that it seems there would be an inability for water to be pumped out of the No 1 water retention dam fast enough to prevent an overflow from that dam and in those circumstances there would presumably have been a 90% run-off (and consequential flooding of the paddock) in any event. What has not been shown is that the severity of the flooding is greater than it would have been in similar events prior to the Alpine Nursery development. 246 Insofar as dry weather conditions are concerned, Mr Dey attributes the fact that the MUSIC Model does not produce an increased water flow off the property in dry weather conditions (notwithstanding that there is a trickle of water in those conditions that passes through the Ellis Road culvert) to its inability to account for instances where water is imported into the catchment other than from rainfall (say for example as a result of irrigation) (pages 8 and 9 of Mr Dey's 11 December 2009 report; pages 3 and 8 of his 18 May 2010 report). The observation of water at the culvert in dry weather is explicable, according to Mr Dey by reference to the fact that there is regular irrigation in dry weather (and he points to this as evidence that some amount of irrigation water must, contrary to the deign of the drainage system, be flowing not into the No 1 water retention dam but, instead, be flowing around the production beds into the Ellis Road culvert). 247 Dr Bayley acknowledged in his 1 July 2010 report that the MUSIC Model did not take account of water entering the catchment from means other than rainfall, that is that the use of irrigation will not be included in the water run-off. However, in response to the assertion that the "trickle" of water observed in dry weather events is as a result of irrigation runoff, Dr Bayley concluded that any irrigation water falling onto the internal roadways will not leave the property unless the soil surrounding the drainage pipes below the roadways has become saturated with water. Dr Bayley considered that the soil would become saturated with water only under intermediate or storm event conditions, not under dry conditions or from irrigation water. 248 As set out in my conclusion on the overall issue in (ii) below, I am not satisfied that the water flow interference, as pleaded, has been established. (b) Quality of Water 249 As noted in answer to question (i), this has not been separately pleaded and I do not consider that a cause of action in nuisance can now be maintained in relation to this complaint. However, I address this issue briefly for completeness. 250 Mr Quick gave evidence as to his observation of the presence of leachate, silt and chemicals in the water flowing onto the cattle paddock (and referred to one occasion when nursery pots which flowed onto his property in a flood) but based his observations as to the quality of the water seemingly solely on the colour of the water (and an assumption that there would be chemicals in it from the spraying he had observed on the Alpine Nursery land). Mr Rolfe accepted in cross-examination that the water retained in the No 1 water retention dam contains nutrients from the fertilisation of the nursery plants and that water is not treated in that dam to remove the nutrients (since those may be used when the water is recycled for irrigation purposes). 251 Therefore, water overflowing from the No 1 water retention dam is highly likely to contain nutrients or chemicals used in fertilising the nursery plants. There is no evidence, however, that would enable me to conclude that this constituted water pollution for the purposes of that definition in the Protection of the Environment Operations Act. That definition requires an assessment to be made as to whether, among other things, the placement or introduction into water (whether through act or omission) of matter changes the chemical or biological condition of the water or is likely to make the water unclean, noxious, poisonous impure or detrimental to health or the like or 'unsuitable for use in irrigation'. In the absence of evidence as to the effect of the alleged nutrients or chemicals I cannot possibly form a view as to the allegation made in relation to the water quality by reference simply to the fact that nutrients/chemicals used for fertilisation are likely to have ended up in the water retention dam. Furthermore, given that the pollution of water under the Act is an offence, a high (Briginshaw v Briginshaw (1938) 60 CLR 336; [1938] ALR 334; (1938) 12 ALJR 100) standard of proof would be required. 252 Furthermore, the passage of the water through the riparian zone may operate to strip some of the nutrients from the water before it reaches the Ellis Road culvert and the Quick Property and there are no tests to indicate that, on the Quick Property, the water is in a state polluted by such nutrients. There was some evidence that the water when tested at Marom Creek was clean but it is difficult from that to infer what the state of the water was either when it left the Alpine Nursery land or when it arrived on the Quick Property, since I do not know what effect the passage of the water through the watercourse may have on its quality at Marom Creek. (In any event, Mr Kerr objected to any such evidence being adduced through questioning of his witnesses on that topic on the basis that water quality had not been pleaded as a ground of nuisance and no evidence had been led by the plaintiffs, other than Mr Quick's lay observations in that regard.) 253 As to the presence of nutrients in the water, Mr Dey maintains that reliance cannot be placed on the MUSIC Model results to conclude that nutrients will have been removed from the water leaving the Alpine Nursery property because he says that the Model wrongly assumes that the swales have some ability to "treat" the water by removing nutrients. Mr Dey is of the opinion that this should be discounted to take account of the fact that water flowing from the Alpine Nursery land when the No 1 water retention dam overflows will not pass through the swales and thus there will be no such opportunity for nutrients to be removed. 254 In relation to the water quality in general (aside from coming to the view that the Water Management Plan of September 2008 was not an effective plan for managing the transmission of blue-green algae from the Alpine property and nor did it provide an effective plan for managing the levels of nutrients and chemicals in water flown from the Alpine property) Mr Dey seems to have come to the conclusion that the water flowing from the Alpine property onto the Quick Property was "likely to have detrimental effects" (p 10 of 27 October 2009 report) based simply on his understanding (derived from the evidence of Mr Quick in his affidavit at [87] and [89] and video footage on DVDs 3 and 4 of exhibit CQ2) (p 10 of 27 October 2009 report) that chemicals are used routinely on the Alpine property by spraying from knapsacks and by tractors. 255 Mr Dey listed the "likely" detrimental effects of the water, given its chemical content, being that the water is less potable for stock, the pollutants from the water would affect the soil structure and the content of nutrients would support species that would not otherwise appear in that terrain (apparently based on his understanding that blue-green algae had been detected on the Alpine Nursery property and downstream). 256 Mr Dey's opinion is not based on his own observations of the use of chemicals, and nor is it based upon actual testing of the water as it flows into the Ellis Road culvert (on the Alpine Nursery side) nor is it based on the testing of water on the Quick Property or the cattle dam. There are no actual test results indicating the levels of chemicals or nutrients in the water on the Quick Property or as it flows off the Alpine Nursery property. 257 Rather, Mr Dey's opinion (that the water flowing from the Alpine Nursery property is likely to have detrimental effects on the Quick Property) seems largely to be based on the assumption that the spraying, as observed by Mr Quick and evidenced in video footage, uses chemicals (there being little evidence as to what types and levels of chemicals are in fact used) and also assumes that such chemicals enter the flow of water which flows off the Alpine Nursery land onto the Quick land (in the absence of any evidence of test results having been carried out to determine the quality of water flowing off the Alpine Nursery). (Evidence was given by Mr Fitzgerald and Mr Wilson, however, as to the regular testing of the water flowing off the Alpine Nursery at least in recent years.) 258 Mr Dey, in his 11 December 2009 report, was of the view that the use of the irrigation recycling system does not reduce the level of nutrients in the runoff water to be of "very little nutrient content" (page 11) on the basis that occurrence of overflow events reduces the effectiveness of the dam in retaining nutrient rich water and preventing it from entering the watercourse. Further, Mr Dey was of the opinion (in his 18 May 2010 Report, at p 10) (albeit on the assumption that the dry-weather trickle flows are run-off from irrigated water, although no testing was done to confirm this) that as irrigation water is taken from the water retention dams, then such trickle flows will be as polluted with nutrients as is the water in the retention ponds. 259 In relation to the quality of the water being discharged from the Alpine property, in his latest report Dr Bayley affirmed his earlier opinion that the level of nutrients and sediments in the water being discharged from the property had in fact decreased since the Alpine Nursery development, relying upon the results of the modified MUSIC Model analysis. 260 Dr Bayley's view is that there is a reduction in the level of nutrients and sediments and an improvement in the quality of the water leaving the property because of the use of the water retention pond (which he says reduces the amount of nutrients and sediments flowing and provides for some treatment of the water in the pond) and on the basis that water otherwise flowing off the property travels through a series of treatment nodes, ie the swales (page 8, 1 July 2010 report). 261 Mr Wilson's evidence is that water in the retention dam is not treated for the removal of nutrients. Therefore, unless the overflow passes through the grass swales (and depending on how efficient those swales may be in any given situation), logically the overflow must carry with it nutrient laden water. Logically also, in the pre-Alpine Nursery development scenario any nutrients in the water running off the property from the potato farm would also have entered onto the Quick Property and there is no basis for any assessment of the extent of those nutrients. Nor is there any evidence of any testing on the water which is on the Quick Property to ascertain whether the presence of nutrients in the water might be such as to constitute an unreasonable interference with their rights and enjoyment of their property. 262 I am not satisfied that the evidence establishes a claim based on the quality of water arriving on the Quick Property. Further, I do not accept that, with the current testing regime in place, there is a reasonable apprehension of further instances when such a nuisance might occur. I accept that there are occasions when Mr Fitzgerald has not been able to perform tests (there being four months identified when records of testing were not available) but those seem to be isolated instances in the scheme of things. The fact that there were elevated levels of some bacteria in the back dams (or that there may be elevated levels of toxicity on future occasions) does not suggest that the testing or treatment regime is on the whole inadequate or inefficient nor does it point to the likelihood of future harm to the Quick Property, in circumstances where the water is monitored and can be treated, where necessary before it leaves the property. (c) reduction in subsurface groundwater/regional watertable 263 Again this issue does not arise on the pleading (which, contrary to this complaint, is that there has been a substantial or material increase in the percolation of water onto the Quick Property). However, had this issue arisen I would have addressed it as follows. 264 In relation to the alleged change to the water table levels, there was agreement on that fact that the development and operation of the Alpine Nursery property had impeded the natural absorption and drainage of surface water flowing from the Alpine Nursery property which has reduced the recharge of the aquifer that supplies the bore (page 9 of 1 July 2010 Report). 265 The area of disagreement in relation to this issue was as to the scale of the impact that the Alpine Nursery development has had on the absorption and drainage of surface water flowing from the Alpine Nursery property. 266 Mr Dey's opinion was that there had been a "significant" decrease in percolation to the water-table and deeper percolation to groundwater from the Alpine Nursery property. What was meant by 'significant' in this context was not explained. Nor was there any explanation given which was capable of being tested insofar as Mr Dey's opinion was said by him to be based on his conclusions regarding "water balance", that is "simple sums within the hydrologic cycle" (page 4, 27 October 2009 report). According to Mr Dey, there is less downward seepage, due to the black plastic lining on the Alpine Nursery property, and this reduces discharge to the watertable. That does not appear to be disputed. What is not clear is how much reduction there has been (and what effect a reduced watertable would have). 267 Mr Dey goes on to conclude that as little or no water penetrates the plastic liner on the Alpine Nursery property there is far less percolation down to aquifers beneath the property and that this reduction in recharge to the acquifer has contributed to the failure of the bore (p 11 of 27 October 2009 report). I have no information however as to the other sources that may contribute to this acquifer. 268 Mr Dey's conclusion rests on two facts – first, that when originally drilled (in March 2005) the bore on Mr and Mrs Quick's property yielded 75 litres/minute in March 2005 and that by September 2006 the bore had failed (as set out in Mr Quick's affidavit sworn 9 October 2010, paragraph 45), despite the increase in above average rainfalls for the corresponding period; and, secondly, that part of the Alpine nursery land has been covered with black plastic which would prevent seepage of water into water table from Alpine Nursery property (p 11 of 27 October 2009 report). In other words, Mr Dey assumes that the failure of the bore is due to a reduction in the watertable level and that such reduction is due to the lining of part of the Alpine land with black plastic. 269 However, as the bore was drilled after the No 1 water retention dam was constructed and after the first lot of plant production areas were completed, it is difficult to see how it can be conclusively said that the failure of the bore is due to the Alpine Nursery development, given that in its initial phase it seems that the bore produced an adequate supply of water. It might be that the explanation for this apparent inconsistency was that, when initially drilled, the bore used water that was present in the groundwater table but that after that was used up there was no recharge to the acquifer from which any further water could be drawn. I am unable, however, to make a finding of that kind in the absence of evidence as to the manner in which the ground watertable would ordinarily be recharged. If the evidence from Mr Rolfe is correct (and there is nothing shown that would discredit it) the perched water table (or underground lake) fluctuates as between different seasons. I am therefore left with little on which to base an assessment that the admitted reduction in recharge to the acquifer is material or a material interference with the watertable. 270 The alleged increase in water flow from the Alpine Nursery property to the Quick Property from the non-lined areas of the nursery (and particularly the allegation that there is a constant trickle from the property even in dry weather would suggest that there remains some opportunity for water seepage into the acquifer). Mr Dey, in his report, is of the opinion that this would only have a limited effect on the local water table immediately under the watercourse caused by the constant wetness. Mr Dey is of the opinion that this effect is "insignificant" when compared with the loss of recharge and general dryness of the greater water-table beneath the entire locality. No basis for the quantitative assessment is given, rather Mr Dey makes the general observation that groundwater supply on the Quick property is influenced by "general loss rather than wetness near Ellis Road" (page 4) to the Quick Property. 271 Dr Bayley described the change to the absorption and drainage of surface water flowing from the Alpine Nursery property (at p 9 of 1 July 2010 report) as being, first, a reduction in the volume of the surface water flow moving from the Alpine Nursery property to the gully that runs through the Quick Property (which relates to the issue addressed in (a) above, and, secondly, a reduction in the ability of soil to absorb rainwater naturally due to the installation of plastic sheeting on a proportion of the Alpine Nursery property. 272 However, Dr Bayley concluded that the development and operation of the Alpine Nursery had not resulted in the inability of Mr and Mrs Quick to pump water from their bore. 273 Dr Bayley points to the fact that there exists no historical monitoring information indicating that the bore had yielded a particular supply of groundwater, or necessarily should have, and he says that as Mr and Mrs Quick's bore was not drilled and operational for a period of time prior to the development and operation of Alpine Nursery there is no guarantee that the bore would have yielded a regular supply of groundwater. 274 Dr Bayley accepted that the Alpine Nursery development would have the effect of reduction of the ability of water to absorb into the soil but he was of the view that the level of the water table is also impacted upon by a variety of other variables many of which are unrelated to the development of the Alpine property, and would also cause a bore to fail, as detailed and explained by him at pages 10 – 13 of his 1 July 2010 report. 275 With respect to Dr Bayley it seems to me that the appropriate conclusion would be, rather, that there is no evidence that the development and operation of the Alpine Nursery had resulted in the inability of Mr and Mrs Quick to pump water from their bore (the difference being that Dr Bayley seems to be relying on the absence of historical data, and the existence of other potential causes, to reach the positive conclusion that it did not). 276 Be that as it may, I am not persuaded that the failure of the bore is due to the fact that there has been a reduction to the acquifer. Nor can I form a view as to the impact of the reduction in the amount of water seeping through the soil on the regional watertable (though it seems to me likely that if this was a real issue it would have been raised at some point by Council or by Cardno Lawson Treloar in their peer review of the water management plan. 277 Finally on this issue, Mr Kerr relies upon Xuereb v Viola and other authority for the proposition, which I accept, that a claim in nuisance in relation to the impact on the underwater acquifer cannot be maintained. (d) Noise and other complaints 278 Once again, this issue was not pleaded and therefore does not need strictly to be addressed. Had it been pleaded, I would have found that there was no evidence from which I could conclude that the noise or aerial spraying of the property or any increased traffic to the property amounted to an unreasonable interference with the enjoyment by Mr and Mrs Quick of their property in circumstances where there is no evidence as to the level of noise or the extent or content of the aerial sprays or of the traffic and how that is said to have affected Mr and Mrs Quick. Conclusion as to issue (ii) 279 Summarising the above, what Mr and Mrs Quick have alleged, in essence, is that there has been a substantial or material increase in the flow (or percolation) or water seepage of surface water to their property (variously described as an increase or change to the velocity or concentration of that flow). They have also alleged an increased incidence of flooding onto the property. The result of this, it is said, is that the southern paddock is permanently water-logged and unusable. (On the view it certainly appeared water-logged, though whether that is a permanent condition or it is permanently unusable may well depend on its future maintenance – in other words, if it, and the adjacent paper road, were cleared of debris and undergrowth so that water coming onto the property through the Ellis Road culvert could be allowed to flow through the property and out to the normal watercourse then it would surely be usable otherwise than in those occasions when there were extreme rainfall events and the evidence suggests the paddock would have flooded anyway.) 280 The cause of the increased flow of water is attributed to the covering of a large portion of the property with impervious plastic sheeting and compacted gravel, the regular nightly or extensive irrigation system the construction of a water storage dam close to the Ellis Road culvert and the diversion of runoff on hard surfaces around the dam and into the Ellis Road culvert. In relation to the last point, prior to the construction of the internal roads, the runoff from that area would still have flowed downhill and ended up in the Ellis Road culvert but it would have done so across a broader expanse of slope widthwise and therefore it is contended that there would have been more natural absorption of the rainfall than is now possible. There is also a channelling or funnelling effect of the water directing it from the internal roads to the culvert which may result in water arriving at the culvert more quickly or in more concentrated form than it otherwise would have done. 281 Mr Kerr submitted that, in order to obtain any relief in these proceedings, it was incumbent on the plaintiffs to establish not only that there has been such an increase in the flow of water but also that the defendants had caused (and their actions will in the future cause) an increase in the flow of surface water to Mr and Mrs Quick's property. Mr Kerr submitted that the plaintiffs had failed to do so. I agree. 282 The expert evidence, which I accept, in essence was that : in intermediate rainfall conditions there has been a reduction (not an increase) in the flow of surface water to the Quick Property; in extreme or storm conditions (whether that be a 1 in 50 year flood or a 1 in 1 year flood – both being said to be rare) there is no (or 'not much') difference if any in the flow of surface water to the Quick Property (Mr Dey put a 10% figure on the difference he sees, though without any empirical evidence; Dr Bayley says there has been a reduction in flow); 283 In dry conditions (somewhat surprisingly at first blush) there seems (and I accept Mr Quick's evidence on this) to be a residual small trickle of water onto the Quick Property (although it cannot be measured against whatever water seepage there might have been pre the Alpine development). 284 Therefore, to the extent that Mr and Mrs Quick assert that the nature and design of the nursery has led to a significant or indeed material increase in flow than would be the case naturally, the expert evidence does not support that proposition. To the extent that they assert that there has been a more concentrated flow of water onto their property than would naturally have occurred, the evidence is not definitive. 285 Certainly, the evidence establishes in my view (and I think this is largely accepted by the Defendants) that the flow of water around and off the Alpine Nursery property has changed since the Alpine Nursery development: first, because that portion of rainwater that falls on the production beds (and is not absorbed into the pots on those beds) and would previously have fallen onto the soil (or the potato crops that were there before the nursery development) is now drained to the No 1 water retention dam and stored there to be recycled for irrigation when necessary; secondly, because the irrigation system has the effect that there is an additional source of water falling onto the property, namely water from dams 2 and 3, a large proportion of which is recycled back to the No 1 water retention dam but a proportion of which if sprayed onto the internal roads will be diverted through drainage under the roadways to the riparian bio-filter and grass swale and thence to the Ellis Road culvert and the Quick Property (and in dry weather any of that which is not absorbed naturally by the soil in that process will end up in the Quick Property); [I note, however, that there is no ability to compare the amount of irrigation that there would previously have been from the potato farm.] thirdly, because of the inability to pump water out of the dam in some cases of extreme rainfall events quickly enough to maintain headspace in the dam to store the run-off from the production beds, it is certainly conceivable that from time to time the No 1 water retention dam will overtop and run through the riparian biofilter zone and grass swale through the Ellis Road culvert to the Quick Property (and that water will contain whatever nutrients have not been stripped in the process and may contain chemicals as well) – prior to the Alpine Nursery development that water would have simply run down the slope (whether or not in a less concentrated flow) (but with little or no absorption in an extreme event – though the point of saturation is not clear); finally, the construction of the levy bank on the eastern ridge of the property means that water from the farms to the east of the Quick Property will be channelled down the side of the Alpine Nursery driveway rather than down that driveway as it did in the past and will converge with water running off the non-production beds from the Alpine nursery in the grass swale and through the culvert to the Quick Property, potentially arriving there more quickly (although that is by no means clear – Mr Rolfe's evidence was that the diversion was not significant and that all water would have ended at the culvert irrespective of the diversion – T152) and in a more concentrated form than before (again, however, the difference was not seen as significant by Mr Rolfe – T 152). 286 Mr Kerr accepted that the irrigation and drainage management system incorporated into the Alpine Nursery (which he described as involving an integrated system of water retention ponds or dams, pumps, drains and treatment systems), has had (and presumably will continue to have) the consequence of increasing at some times and decreasing at other times the surface water flows at particular locations within the Alpine Nursery. He accepts that the black plastic sheeting on the garden beds on the northern slope of the nursery is likely to increase the flow of surface water in some (though not all) conditions compared with the position if there were no black plastic sheeting (when more water would be able to be absorbed into the soil). Dr Bayley further accepts that this has the effect that there is a reduction to some extent in the recharge to the underlying acquifer or ground watertable. 287 What Mr Kerr did not accept was that the deterioration in the condition of the southern or cattle paddock (which was such that only a few individuals ventured into the boggy marsh at the time of the view) had been caused by any increase in water flows attributable to the defendants or that it amounted to a nuisance. 288 Insofar as the state of the southern paddock is concerned, it was clearly prone to flooding well before the Alpine Nursery development (and Mr English gave evidence of such events). Mr Quick's evidence suggests that the paddock has flooded more frequently since the development. Based on Mr English's evidence it seems likely that that is the case. That in itself does not necessarily amount to an unreasonable interference with land already flood prone. 289 Mr and Mrs Quick's real complaint, it might be thought, is that the southern paddock is now waterlogged and they say unusable. 290 Dr Bayley, however, posited the likelihood that the current state of the paddock is due to the obstruction of the flow of water out of the paddock by reason of the weeds and grass in the paddock itself and the debris and material clogging the boundary fences. Mr Kerr also points to the fact that, unlike Mr English, Mr Quick has not kept the adjacent paper road clear of vegetation as Mr English had done. 291 Overall, the defendants contend, and the experts seem broadly to agree, that the effect of the irrigation system in place at the Alpine Nursery is that less water now flows onto the Quick Property than would otherwise have been the case in all but dry conditions and that in those conditions it is no more than a trickle. It is possible that the constant 'trickle' observed by Mr Quick is due to irrigation from the Alpine Nursery (but in my view that could not be described as a substantial or material increase in water flow). 292 The defendants rely on Dr Bayley's analysis, based on his computer modeling, which is that the combined effect of the irrigation and drainage system is to reduce the total amount of the surface water flowing onto the Quick Property in all conditions. Mr Kerr submits, based on that analysis, that insofar as the overtopping of the dam is concerned, the consequences of the irrigation and drainage system may be measured by a comparison between the storage capacity of the (undeveloped) soil and the storage capacity if the No 1 water retention dam. This is because, in storm events of the kind which will cause the dam to overtop the position in pre-Alpine conditions was that the soil would at some point have reached saturation point with the result that it would ultimately act as an impervious surface just as the black plastic sheeting does and in the post-Alpine development conditions the surface water instead of running down the hill at that point is instead collected up to the maximum capacity of the dam before it overspills. 293 Mr Kerr submits that Dr Bayley's calculation shows that the storage capacity of the soil is less than the storage capacity of the lower dam and thus that the surface water which would have flowed down the surface of the uncovered land in extreme pre-Alpine conditions would exceed the amount of the overflow from the lower dam in extreme post Alpine conditions. I accept the logic of that submission. 294 What Dr Bayley's calculations do not necessarily permit is an assessment of the difference (if any) in terms of timing of the water flow as it reaches the Quick Property in those conditions. In other words how the point at which the soil saturation is reached in the pre-Alpine conditions compares with the point at which the dam is likely to overtop. However, Dr Bayley's assessment was that in a 12 hour period there would be no relevant difference and Mr Rolfe (who was largely responsible for the design of the system and is an author of the nursery industry best practice guidelines) was also of the view that there would be little if any difference. 295 Mr Kerr submits that one can infer from Mr Rolfe's evidence that the irrigation and drainage system was designed so as not substantially to change the net surface water flow in the natural direction of that flow and that the design satisfied that intention (by reference to the Council's observations in a letter of 11 August 2006 to Mr Quick and the Council's assertion that the water storage facility was not expected to contain all the runoff from production areas in large or exceptional rainfall events). Further, the development consent conditions required that all surface runoff from the areas other than the nursery (presumably a reference to the nursery production beds) was to be diverted around the water storage facility. Whether or not an inference of the above kind should be drawn is by no means a simple issue. 296 I have indicated above my assessment of the respective experts. In general, I have more confidence in the analysis of Dr Bayley, which seemed to me to be balanced, logical and consistent with the objectives with which the industry expert designed the Alpine Nursery irrigation system. 297 In conclusion, therefore: I accept the joint experts' conclusion that in intermediate rainfall events there has been a decrease in the amount of water flowing onto the Quick Property from that which would have flowed but for the alterations in the conformation or use of the Alpine Nursery from May 2004. In light of the evidence given by Mr Dey during the hearing, I am unable to conclude that during extreme rainfall events the water flowing onto the Quick Property is substantially or materially more than would have been the case but for the alterations in the conformation or use of the Alpine Nursery. Further, while I accept that there has been a greater incidence of flooding since 2004 than in the years 2001 to 2004 (and the defendants' Nursery Manager, Mr Wilson, concedes that the dam is likely to overflow two or three times a year and Mr Rolfe accepts that there will be times , in heavy rainfall, where the dam will overflow – T 137.44), I am not satisfied that this is flooding that would not have occurred or would not in the future occur but for the alterations in the conformation and use of the Alpine Nursery land. I accept as logical, and consistent with Dr Bayley's modelling, Mr Rolfe's explanation that by the time the dam overflows all other catchments that are contributing substantial run-off would also be going to the Quick Property and that it is a natural occurrence in that regard – T137.46. As a matter of commonsense, in dry weather conditions any amount of water flowing (or, perhaps more accurately, trickling) onto the Quick Property must represent an increase over that which would otherwise have come onto the Quick Property (unless there was always a residual trickle of water onto the property). Further, it seems probable that the source of that trickle is irrigation on the Alpine Nursery land (since in dry weather conditions the perched water table is said to be low – so presumably the trickle would not be from water seepage, although there was no evidence on this issue - and it seems to me likely that any small amounts of irrigation from other properties would be absorbed before reaching the Ellis Road culvert). However, even if the sole source of water coming onto the Quick Property in dry weather is irrigation runoff from the Alpine Nursery land, I am not satisfied that such runoff would amount to a substantial and unreasonable interference with the use or enjoyment by Mr and Mrs Quick of their land. 298 Mr Dey described the effect of the trickle and explained why he considered that even a trickle of water (if constant) in dry conditions would cause damage to the plaintiffs' land (from T 257.7): HER HONOUR: This issue commenced with questions relating to the observations of the water and the behaviour of the water in the boggy paddock that some of us walked through on Monday. WITNESS DEY: Okay, thanks, I'll start with my reasons, the reasons why I think it's boggy, but I'd also like to address some of the things that Dr Bayley said. HER HONOUR: Yes. WITNESS DEY: I think it's boggy essentially because it's having water delivered to it on a fairly constant basis, during any time, when it would have weather conditions which would dry it out and I understand, it's my belief from having viewed the site and from descriptions of it, that there is water arriving at that particular boggy area on a daily basis and it's my belief also that that's true due to the irrigation upon the nursery. The arrival of the water in that soil area keeps it wet and allows species to grow and also to grow to a thickness which they would not be there and the other species which would be there wouldn't grow to that thickness if the soil was allowed to dry out, generally speaking, which is what would normally happen in an area like that. Over say a one or two months period, when there's little rain, that soil would be dry and would behave in a similar fashion to the soil on the hillsides around it; in other words, it could be slashed, grasses could be kept short and it would be able to be maintained and the soil itself would dry out as a result of not being constantly wet. If I can refer to some of what I saw Mr English talk about, he mentioned there would be a three day period when he wasn't able to get in and slash the grass and that's, if you like, the situation prior to the nursery activities and that, to me, illustrates what I'm saying. HER HONOUR: And do you accept that if somebody were to remove the debris from the fence and slash or remove the weeds and foliage in the paddock, that would facilitate more of a flow out of that paddock than is presently possible? Leaving aside the hydraulic barriers constituted by what's in the paper road at the moment, do you accept that what's in the paddock at the moment constitutes a barrier to the water leaving the paddock? WITNESS DAY: I accept it but I would like to put a scale on it, which is it's my view that the input of constant water has far more effect than could the removal of the existing vegetation and the clearing of any debris on the fence . (my emphasis) KERR: Mr Dey, could I ask you have you undertaken any calculations in relation to that point that you've just made? When you say "on a scale", have you calculated what would happen if, for example, the fence line was cleared, I'll use a non-technical term, foliage on the paddock was removed or cut down to short grass length? WITNESS DEY: No, I haven't undertaken those calculations but if I could refer back to what you and I discussed yesterday about my experience, in observing the behaviour of water in flood situations I have looked at many a floodplain with water flowing through it. For example, it's my observation that when the more firm parts of a plant, meaning trunks of trees or the round stems, occupy water, they don't inhibit the movement of that water until they occupy probably two thirds of the water space. So I haven't made a calculation but I'm experienced in these things . (my emphasis) 299 I do not accept that (balancing the rights of both neighbours) it is unreasonable for Alpine Nurseries to irrigate its land, simply because that may lead to a trickle of water on their neighbours' property, without more. If water were able to flow out of the Quick Property (as it seems to have done in the past) onto the Marom Creek watercourse, then commonsense seems to suggest that a trickle of water would not be the cause of a permanently waterlogged paddock. (And in this regard, I note that commonsense in the treatment of expert evidence seems to have been advocated by the former Chief Judge in Equity (Young CJ) in Vella v Permanent Mortgagee Pty Ltd [2008] NSWSC 505, at [245] – [248], citing Chan PJ in Nina Kung v Wang Din Shin [2005] HKCFA 54, although admittedly there in a very different context.) 300 I accept that, at least in some rainfall events, the velocity with which water arrives at the Quick Property may be greater than would have been the case prior to the alterations in the conformation and use of the Alpine Nursery land (or, to put it in other words, the path by which water arrives at the Quick Property in some rainfall events means that the flow of water is more concentrated than it would otherwise have been). I am not satisfied that this constitutes a substantial or unreasonable interference with the use or enjoyment of the Quick Property. 301 Therefore, I do not find that the water flow interference has been established as constituting a substantial and unreasonable interference for the purposes of establishing any nuisance. (iii) Assuming a substantial and unreasonable interference, is this nevertheless a natural use of the Alpine Nursery land? 302 Given my finding above, again, this strictly does not arise. Had I found there to be a substantial and unreasonable interference with the use and enjoyment of the property by Mr and Mrs Quick arising from one or more of the matters said to have constituted water flow interference, then the next question would be whether this was a consequence of a 'natural use' of the Alpine Nursery property. Once nuisance is established, if the defendant can prove that the use of the land causing the nuisance is nonetheless a natural or reasonable use of such land, then the defendant will not be liable for nuisance. 303 Mr and Mrs Quick allege that where the nuisance alleged is damage caused by water entering their land, it is sufficient (in order to establish a prima facie case) for them to allege and prove that material damage to their property has resulted from an increase in the flow or percolation of surface water due to the defendants' act in altering the conformation of land in the course of the defendants' use of it and that it is not for them to allege or prove a non-natural or unreasonable use of the land by the defendants (though they have in fact alleged that the use of the land was a non-natural use – see paragraph 20 of the pleading). 304 This is consistent with what was said in Corbett v Pallas (1995) 86 LGERA 312 by Priestley JA (with whom Meagher JA agreed and Mahoney JA generally agreed): 1. Where the nuisance alleged is damage caused by water entering the plaintiff's land it is sufficient in order to establish a prima facie case for the plaintiff to allege and prove that material damage to his property has resulted from an increase in the flow or percolation of surface water due to the defendant's act in altering the conformation of land in the course of the defendant's use of it. 2. It is not for the plaintiff to allege or prove unnatural or unreasonable use of the land by the defendant. 3. So far as the conformation of the land is altered in the course of some specific use which may avoid liability, the burden of proof is on the defendant to allege and establish it as a distinct defence. 4. Unreasonable use is not an ingredient of the cause of action but certain types of user may amount to a "natural" and reasonable user of the land and afford a defence. 5. Whether a particular user of land is "natural" must be determined reasonably having regard to all the circumstances, including the purposes for which the land is being used and the manner in which the flow of water was increased. (my emphasis) 305 As to what will constitute a natural use for the purposes of a claim in nuisance, Windeyer J in Gartner said: It seems appropriate to observe here that the notion of a natural use of land, and the distinction between a natural and a non-natural use seems to have come into the law at this point from Lord Cairns' judgment in Rylands v. Fletcher [1868] UKHL 1; (1868) LR 3 HL 330, at pp 337-340 : see the article by Professor Newark in 24 Modern Law Review, 557. The concept involved is a difficult one; and in formulations of the law of nuisance it may be better to start with what Bramwell B. said in Bamford v. Turnley [1862] EngR 907; (1862) 3 B & S 66 (122 ER 27) , that " acts necessary for the common and ordinary use and occupation of land and houses may be done, if conveniently done , without subjecting those who do them to an action" (1862) 3 B & S, at pp 83, 84 (122 ER, at p 33) . By "conveniently done" the learned Baron meant, no doubt, done in a reasonable and proper manner . He contrasted such user with a use "not unnatural nor unusual, but not the common and ordinary use of land" (1862) 3 B & S, at p 83 (122 ER, at p 33) . However, the expression "natural use" has come to be much used in discussions of this topic, and I have adopted it later in this judgment. (at p45) (my emphasis) 306 Whether a particular use of land is 'natural' must be determined reasonably having regard to all the circumstances, including the purposes for which the land is being used and, in the present case, the manner in which the flow of water was increased. 307 Reliance was placed by Mr Philips on what was said in Bayliss per Manning J at 542 to the effect that the mere fact that the operations of the defendant constitute a natural use of the land does not necessarily relieve the defendant from liability for all of the consequences of the gravitational flow of rainwater onto the lower land. It is said that a higher landlord may in some circumstances be under a duty to protect an adjoining lower land at against water which falls naturally upon and runs from the surface of its land if, by its act, the natural flow is altered resulting in damage to the lower land and such act is not necessary for the common and ordinary use and occupation of the land was done in an unreasonable manner or to an excessive degree. (my emphasis) 308 Mr Kerr places reliance on what was said in Bell v Pitt [1956] Tas SR 161 at 181 (which was quoted with approval in Gartner) per Burbury CJ and on the judgment of Priestley JA in Corbett v Palas (at 317)(there summarising the principles stated in Bell v Pitt, Gartner v Kidman and Kraemers v Attorney General (Tas) [1966] Tas SR 113) and maintains that the use of property (previously used for agricultural purposes and located in an area with farming and agricultural properties) for a plant nursery is a natural use, as is the construction of a dam and drainage system on that property. 309 In Bell v Pitt, the Court said: The owner of a farm is entitled to establish a reasonable system of drainage on his own farm by means of artificial channels for the purpose of its better cultivation and the owner of the lower lying property which in consequence of the establishment of that drainage system receives surface water in increased concentration and quantity has no cause of action. The establishment of a reasonable system of drainage in the ordinary use of a farm for the purposes of better cultivation constitutes in my opinion the natural user of farm property within the common law principle . The limits of that natural use cannot be defined by definition and each case must depend on its own circumstances. The right is clearly not absolute ... If the operations are carried in the ordinary use of the property and are carried out with due care and skill the adjoining owner cannot complain if, as an incident of the artificial interference with the surface of the ground, water overflows onto his property through gravitation or other natural causes in a greater concentration or quantity. (my emphasis) 310 Mr and Mrs Quick seem to draw a distinction here between 'normal' farming use and use on the scale that is apparent here. However, there is nothing that suggests that the test is whether the property is used for commercial purposes or for private purposes (unless it is suggested that this is what was meant by reference to an excessive user in the authorities referred to above). 311 It seems to me that, notwithstanding the scale of the nursery operations on the Alpine Nursery land, its use as an agricultural (or, perhaps more precisely, horticultural) use, falling within the relevant zoning, is a natural use of the land in the sense of the common and ordinary use of agricultural land (just as the macadamia farm or potato farm or cattle farm of which there was evidence in the area) and that the installation of a reasonable system of drainage (as the objective assessment of the peer reviewers and the conclusion of the Council seems to be) is also a natural use. 312 In those circumstances, even if I had found that there had been a substantial or unreasonable interference amounting to nuisance on the part of the defendants, I would have been satisfied that this was a natural use and they would not have been liable for such a nuisance. (iv) Is there apprehended nuisance, which would give rise to quia timet injunctive relief? 313 In Melaleuca, it was said that (at [24]); For the claim to injunctive relief, evidence of past discharges could found a finding that unless relief was given nuisances are likely to occur, and consequentially that the relief should be given. The relevant conduct of the respondent could nonetheless be its past conduct creating the state of affairs whereby the water was discharged and would be discharged onto the appellant's land. As was said in Bankstown City Council v Alamdo Holdings Pty Ltd at [43]-[44], discussing the availability of the "good faith" defence, depending on what the council had done or omitted to do, in answer to a claim for injunctive relief - "43. The propositions that (1) injunctions are generally directed towards requiring or preventing future events and (2) evidence of actions performed in the past by the defendant will show that which is apprehended to be reasonably probable, may be accepted. But this does not deny that the susceptibility of a defendant to suffer equitable relief quia timet may be said to be in respect of what has already been done by the defendant . That which presents the threat has already occurred. 44. The equity which the plaintiff has in such circumstances is not equated with an accrued right to sue on a cause of action at law in contract or tort. Equity responds to threats of future injury to legal or equitable rights." (emphasis added in original) 314 I am not satisfied that there have been past acts of nuisance for the reasons set out above. As to future or apprehended nuisance, I am satisfied that the defendants have taken reasonable steps to minimise harm to their neighbour's property and I am not satisfied that there is a basis for a reasonable apprehension of future nuisance (albeit that the risk of flooding remains). (v) Negligence 315 For the reasons given earlier, Mr and Mrs Quick are not in a position to maintain a claim in negligence, it not having been properly pleaded. Had such a claim been able to be maintained, I would nevertheless not be satisfied that the plaintiffs had established such a claim in this case. 316 As to whether a duty of care could be said to have arisen on the part of the defendants, of the kind particularised, I note that Preston CJ in Robson v Leischke (from [93]) summarised what the plaintiff needs to prove to succeed in a cause of action in negligence and noted that in relation to the question whether a duty of care has arisen there is not yet one unifying principle describing when the existence of a duty of care will arise (Perre v Apand Pty Ltd (1999) 198 CLR 180, at 210 [76], 217 [93]). 317 In Perre v Apand, the High Court said that, at a minimum, there needs to be reasonable foreseeability: a defendant must know or ought reasonably to know that he or her conduct is likely to cause harm to the person or the tangible property of the plaintiff unless the defendant takes reasonable care to avoid that harm (at 208 [70] and see also s 5B(1)(a) of the Civil Liability Act 2002 (NSW)). As summarised by Gummow J in Perre v Apand, (at [70]): Where a defendant knows or ought reasonably to know that its conduct is likely to cause harm to the person or tangible property of the plaintiff unless it takes reasonable care to avoid that harm, the law will prima facie impose a duty on the defendant to take reasonable care to avoid the harm. Where the person or tangible property of the plaintiff is likely to be harmed by the conduct of the defendant, the common law has usually treated knowledge or reasonable foresight of harm as enough to impose a duty of care on the defendant. Where a person suffers pure economic loss, however, the law has not been so willing to impose a duty of care on the defendant. By pure economic loss, I mean loss which is not the result of injury to person or tangible property. 318 The difficulty, however, is in identifying what other requirements, if any, need to be satisfied before the law will impose a duty of care. As Preston CJ noted, proximity has not been accepted as determinative of the existence of a duty of care (Hill v Van Erp (1997) 188 CLR 159, at 176-177, 210, 237-239; Perre v Apand Pty Ltd, at 198 [27], 209 [74], 283 [280], 301 [330]-[331]; and Vairy v Wyong Shire Council (2005) 223 CLR 422, at 433 [28] and 444-445 [66]). Other factors have been suggested (see Perre v Apand, at 194 [10]-195 [15], 231 [133], 254 [201], 275 [259], 303 [335], 326 [406]) but no consensus has emerged in this regard. 319 That said, the relationship between the owners or occupiers of neighbouring properties is a category where the common law frequently recognises that a duty of care to one's neighbour will arise (Robson, at [96]). 320 Here, I have little difficulty accepting that a duty of care would have arisen on the part of the defendants to take reasonable steps to avoid damage arising from excessive water flows arising from action taken by them on their property (even if that otherwise amounted to a natural use of the property) if they knew or ought to have known that physical damage to Mr and Mrs Quick's property was likely to result from their actions. In this sense, as recognised in Robson there is an overlap (though not a complete overlap) between the torts of nuisance and negligence. 321 Where I have difficulty with the particularised duty of care in this case is in accepting in the abstract that the defendants owed a duty of care to their neighbours to comply with the development consent conditions imposed by Council. (It might be the case that if it were reasonably foreseeable that loss and damage would be suffered if there were to be a breach of one or more of the Council's consent conditions then a duty of care would arise to prevent the loss or damage so arising but I doubt that this would be said to be a duty of care to comply with the Council consent conditions.) 322 Assuming that a duty of care of the first mentioned kind had arisen in relation to the conduct and operations of the nursery, could it be said that a breach of that duty of care had occurred (by reason of a failure to do what was reasonable in response to that risk of loss or damage)? In Wyong Shire Council v Shirt (1980) 146 CLR 40, at 47-48 Mason CJ said: In deciding whether there has been a breach of the duty of care the tribunal of fact must first ask itself whether a reasonable man in the defendant's position would have foreseen that his conduct involved a risk of injury to the plaintiff or to a class of persons including the plaintiff. If the answer be in the affirmative, it is then for the tribunal of fact to determine what a reasonable man would do by way of response to the risk. The perception of the reasonable man's response calls for a consideration of the magnitude of the risk and the degree of the probability of its occurrence, along with the expense, difficulty and inconvenience of taking alleviating action and any other conflicting responsibilities which the defendant may have. It is only when these matters are balanced out that the tribunal of fact can confidently assert what is the standard of response to be ascribed to the reasonable man placed in the defendant's position. 323 This statement of principle has been repeatedly approved and applied: see, for example, Brodie v Singleton Shire Council (2001) 206 CLR 512, at 577 [151]; Woods v Multi-Sport Holdings Pty Ltd (2002) 208 CLR 460, at 472 [39], 482 [72] and [74], 502 [138]; Graham Barclay Oysters Pty Ltd v Ryan (2002) 211 CLR 540, at 585 [106]-[107], 612 [193]; Vairy v Wyong Shire Council, at 433 [27], 447 [72], 456 [105], 464 [134] and 466 [144]. 324 Here, the defendants appear to have gone to extensive lengths to put in place an irrigation and drainage management scheme which will minimise the risk of harm from excessive water flows onto the Quick Property. Relevantly, even Mr Dey (who suggested that further remedial steps should be taken) was unable to say that those steps would be effective. Mr Dey, in what seems to be his typical broadbrush style, criticises the current water management plan as ineffective. That plan has, however, been subject to considerable security not just by the Council but by independent engineering experts, and has been approved. It is difficult in those circumstances to suggest that there has been any failure by the defendants to take reasonable steps in response to the risk of flooding (particularly having regard to the fact that the risk is simply that an area of land on the Quick Property that is already flood prone will continue to flood and that this may occur with a greater incidence depending on weather conditions). 325 In any event, I am not satisfied that Mr and Mrs Quick have established that the loss and damage on their property (in terms of the damage to their boundary fences or the boggy state of the paddock) was caused by any conduct on the part of the defendants which might have been said to be in breach of any duty of care. I am not satisfied that Mr and Mrs Quick have suffered loss or damage as a result of any increased velocity or flow of water caused by the defendants as a result of the alterations to the conformation of the Alpine Nursery land or the use of the nursery, as pleaded. In relation to the flooding of the paddock and the damage occasioned to the fence at the boundary of their property, I cannot be satisfied that this would not have occurred in any event as a result of water flowing through the property along the natural watercourse (or, since November 2005, as a result of the actions of the Council in extending the Ellis Road culvert). In relation to the May 2005 incident when water with elevated blue-green algae levels came onto the Quick Property no damage has been shown as a result. 326 I should note that Mr and Mrs Quick claimed to have suffered a diminution in the value of their land (by reference to the fact that the southern paddock is now permanently waterlogged). They sought to rely on evidence from the Valuer-General in which an objection they had made to the valuation of the land for land tax purposes was upheld by the Valuer-General (following an assessment of their objection by a contract valuer). 327 When the matter came before me for preliminary evidentiary rulings, prior to the hearing, objection was taken to the admission into evidence of material going to that assessment by or on behalf of the Valuer General of the Quick Property for land tax purposes. Mr Robertson, for the defendants, raised this objection on the basis that this was an attempt to use opinion or expert evidence in relation to the value of the land (or any diminution in value of the land) without compliance with the requirements for the adducing of expert or opinion evidence in this Court and in circumstances where no file from the Valuer General had been produced. Even if (which he submitted it was not), the evidence were otherwise admissible, a section 135 objection was taken by Mr Robertson. Mr Philips sought to press the admission of this evidence as being within the business records exception to the hearsay rule in order to establish not that there had been a diminution in value of any particular dollar amount but merely that, as 20 April 2009, armed with the assumptions stated in the letter, the Valuer General (having engaged an external consultant contract valuer), was prepared to accept that there had been some diminution in value of the plaintiffs' property for it the reason stated in the letter. 328 After debate on that issue I admitted that material under the business records exception as evidence of the fact that there had been a valuation for a stated purpose, which had produced a figure, but not as to the truth of any underlying opinion as to the value of the property (and subject to relevance and weight). Acceding to Mr Robertson's application on this point, I gave a section 136 direction that this evidence (paragraphs 91 and 53 and pages 1 and 4 of tab 62 of Exhibit CQ1), was not to be used for the purpose of proving the value of the property at any particular time or that there was a diminution in value of the property at any particular time. 329 During the hearing that evidence was again sought to be tendered (documents having become available from the Valuer-General's file). Mr Kerr maintained the objection to the admission of that evidence on the basis previously put and, due to the lateness of the evidence and its lack of probative value as I saw it, I rejected that evidence for reasons which I gave orally during the hearing. 330 The upshot of that is that there is no evidence of the value of the Quick Property at any relevant time or of any diminution in the value of that property. (For the defendants, I note that it is submitted that even if such evidence had been available, and a claim in nuisance established, there would be no entitlement to compensation in nuisance for the depreciation in value of the property relying on McKenzie v Powley [1916] SALR 1, and that the plaintiffs would have been restricted to a claim for loss of the comfort or enjoyment of their property.) 331 I am not satisfied that Mr and Mrs Quick have established actual physical damage to their land caused by any breach of a duty of care owed to them. Therefore, their claim in negligence could not have succeeded even had I allowed it to be maintained. (vi) What remedy, if any, should be granted in light of the findings in respect of the above matters? 332 As to the question of remedy, reliance is placed on what was said by the Master of the Rolls in Pride of Derby V British Celanese Ltd [1953] Ch 149, namely that if a plaintiff proves that his or her proprietary rights are being wrongly interfered with by the defendant and that the defendant intends to continue the wrong, then the plaintiff is prima facie entitled to an injunction and will be deprived of that remedy only in special circumstances exist. 333 Nevertheless, even had I found there to be an apprehended nuisance, I would not have granted an injunction in the terms claimed (notwithstanding that I accept the degree of similarity with the relief granted in Melaleuca) because of my concern that it would be impossible for the defendants in the future to know whether they were at any time likely to be in breach of the relevant orders (Qantas Airways Ltd v Cameron (1996) 66 FCR 246; ICI v Trade Practices Commission (1992) 38 FCR 248; Greetings Oxford Koala Hotel Pty Ltd v Oxford Square Investments Pty Ltd (1989) 18 NSWLR 33, see also Young, Croft and Smith, On Equity, Lawbook Co, 2009, at [16.270]). 334 Mr Philips submits that it should not be for the plaintiffs to fashion the relief, since it is not their business venture. However, I see no reason why Mr and Mrs Quick could not have obtained expert advice as to how the problem that they contend has been caused by the defendants' nuisance and which they apprehend will continue to occur could be remedied and to have adduced evidence of that. (In fairness to the plaintiffs' legal representatives, it appears that they sought to do so through Mr Dey but his evidence was not sufficiently conclusive to permit me any conclusion to be drawn as to the best way to remedy the nuisance or to prevent future nuisance had I found there to be such a nuisance.) At best, therefore, I would have ordered an enquiry as to how any such nuisance could be remedied or prevented from occurring in future or sought submissions as to whether it would have been appropriate to do so. 335 As to the claim for damages, during closing submissions, Mr Philips contended that as to the claim for damages a sum of $40,000 - $50,000 would be appropriate for the interference with the loss of enjoyment of the land. 336 Nominal damages will be awarded where no actual damage is caused, but there is nevertheless an interference with the plaintiff's rights of use and enjoyment of land. Thus, in Roberts v Rodier, Campbell J considered the relief to be granted where the plaintiff had been deprived of pedestrian access to the plaintiff's property for a period of around 3½ years and adopted the principles set out in Bone v Seale (at 804-5) by Scarman LJ and accepted by Harris J in Oldham v Lawson (at 658) and by Gillard J in Stockwell v Victoria [2001] VSC 497 (at [483]) (noting that 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). His Honour set out the observations of Scarman LJ in Bone v Seale, as follows: 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." 337 In Bone v Seale, assistance of a general kind was able to be derived by reference to amounts recoverable in the area of personal injury litigation, noting the range of awards made for the element of loss of amenity, with a view to permitting consistency when dealing with analogous situations. Scarman LJ also referred to the further general principle that in attempting to measure damages for non-pecuniary loss, an element in assessing reasonableness is the fairness of the compensation to be awarded. His Lordship considered that there must be moderation and that some attention must be paid to the rights of the offending defendant as well as to the rights of the injured plaintiff. 338 Had I been satisfied that there was an actionable nuisance and that the land had been damaged as a result I would have considered it appropriate to award damages to cover the cost of repair of the fence and restoration of the paddock to its former condition. However, in the absence of evidence as to what those amounts would have been I would have been limited to nominal damages (which I would have fixed, without any pretence at a scientific assessment of the amount, in the order of somewhere between $10,000 and $20,000 to cover repair costs and general loss of enjoyment). Conclusion 339 I appreciate that the plaintiffs feel greatly aggrieved by the nature and scale of the commercial nursery operations being carried on across the road from their property. I accept that they have a genuine apprehension that harm is being visited upon them in the form of polluted water and/or other pollution from the operations at the nursery and I accept that the state of their southern paddock is a matter of concern for them. However, I am not satisfied that they have established a claim in nuisance and I am satisfied that the defendants have taken reasonable steps to minimise any harm to the plaintiffs arising out of their nursery operations. 340 I therefore dismiss the plaintiffs' claim with costs. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.