NOTTINGHAM FOREST TRUSTEE LIMITED v UNISON NETWORKS LTD [2021] NZCA 227

NOTTINGHAM FOREST TRUSTEE LIMITED v UNISON NETWORKS LTD [2021] NZCA 227 [3 June2021]IN THE COURT OF APPEAL OF NEW ZEALANDI TE KŌTI PĪRA O AOTEAROACA523/2019[2021] NZCA 227BETWEEN NOTTINGHAM FOREST TRUSTEELIMITEDFirst AppellantROGER DICKIE (N.Z.) LIMITEDSecond AppellantFOREST MANAGEMENT (NZ) LIMITEDThird AppellantNOTTINGHAM FOREST PARTNERSHIPFourth AppellantAND UNISON NETWORKS LIMITEDRespondentHearing: 8 September 2020Court: Cooper, Clifford and Collins JJCounsel: C T Walker QC, A L Sweeney and I J Thain for AppellantsJ B M Smith QC and S B McCusker for RespondentJudgment: 3 June 2021 at 10.30 amJUDGMENT OF THE COURTA The appeal is dismissed.B The cross-appeal is also dismissed.C The appellants must pay the respondent costs on the appeal calculated fora standard appeal on a band A basis, and usual disbursements. We certifyfor two counsel.D The respondent must pay the appellants costs on the cross-appeal on thesame basis, and usual disbursements. We certify for two counsel.____________________________________________________________________REASONS OF THE COURT(Given by Cooper J)Table of ContentsPara No.Introduction [1]Facts [6]Unison's claim in the High Court [15]The High Court judgment [23]The appeal [38]Discussion [43]Nuisance [43]Rylands v Fletcher [72]The cross-appeal [87]Result [94]Introduction[1] Over a period from December 2010 to August 2016 pine trees growing ina commercial forest owned and operated by the appellants (Nottingham Forest),1which had been planted many years earlier, fell onto two electricity lines owned andoperated by the respondent, Unison Networks Ltd (Unison). There were poweroutages to Unison's customers while repairs were carried out.[2] Unison commenced proceedings in the High Court in relation to one of theaffected lines. Its claim was advanced in nuisance, Rylands v Fletcher and negligence.It sought damages reflecting the cost of repairs and an injunction to prevent continuingfalls onto the line.1 There are four named appellants, who either had a proprietary interest in the forest or wereconcerned in its operation and management: Nottingham Forest Trustee Ltd, Roger Dickie (N.Z.)Ltd, Forest Management (NZ) Ltd and Nottingham Forest Partnership. With a few exceptions, itis unnecessary to distinguish between these parties for the purposes of this judgment and we referto them collectively as "Nottingham Forest".[3] Ellis J found in favour of Unison in both nuisance and Rylands v Fletcher.2The Judge considered that negligence had not been established. She awarded damagesbut declined injunctive relief.[4] Nottingham Forest appeals, asserting that its only potential liability was innegligence and that it could not be liable in nuisance or Rylands v Fletcher. It saysthat since it was not at fault in its management of the forest, Unison is not entitled torelief against it. In the circumstances that arose, Unison was itself liable to meet thecosts of repair and suffer what consequences might arise from future tree falls in thevicinity of the line.[5] Unison counters that the High Court correctly found Nottingham Forest liablein nuisance and Rylands v Fletcher. It also cross-appeals, asserting that it should havesucceeded on its negligence claim and on its claim for injunctive relief.Facts[6] The essential facts can be succinctly stated. The forest comprises a little over150 hectares and contains at least 30,000 trees. The land was in use as a beef andsheep farm before its acquisition by Nottingham Forest in the early 1990s. The treesare Pinus Radiata and were planted in 1994.[7] Unison owns two power lines that run through the forest: An 11kV line anda 33kV line. The section of the 11kV line through the forest is 495 metres long andthe section of the 33kV line through the forest is 394 metres long. The proceedingconcerned damage to the latter line, known as the Esk Feeder (the line). It wasestablished in the late 1960s or early 1970s, and there was no dispute in the High Courtthat Nottingham Forest knew of its existence at the time the forest land was acquired.3There is a corridor around each of the lines, in each case approximately 30 metreswide in total, where no trees have been planted. The nearest tree to the line is plantedabout 15 metres away from it.2 Unison Networks Ltd v Nottingham Forest Trustee Ltd [2019] NZHC 2280 [High Court judgment].3 At [23].[8] The trees on the edge of the corridor grew to a height that was greater thantheir distance from the line some time between 2002 and 2008. However, in forestryterms, Pinus Radiata are not at their optimum maturity until they reach a height of30 metres. On average the trees were 13.8 metres tall in 2002, 20 metres in 2008 and38 metres in 2018. Harvesting of the trees was not scheduled to start before the endof 2020. The Judge found that by 2010 the trees planted on the edge of the corridorhad grown taller than the full distance between those trees and the line. In thecircumstances, there was what the Judge described as "a very good chance" that theline would be hit, and damage caused by falling trees.4 In fact, that began to happen,with trees falling and causing power outages in December 2010 and July 2011.Further, in September 2013, a windstorm resulted in a tree fall causing $20,000 worthof damage to a structure on the line. In addition, there were outages on the 11kV lineas a result of tree falls in April 2012 and January and November 2014.[9] On 27 February 2015, Unison sent the third appellant, Forest Management(NZ) Ltd (FMNZ), a notice referring to potential liability for damage caused by treesfalling on the lines and recommending that trees be cleared to prevent further damageto the lines. This was resisted unless there was appropriate compensation.[10] Two trees fell and hit the line on 24 September 2015 (referred to by the Judgeas the "First Strike").5 The trees were around 31 metres in height and had beengrowing on a slope on the edge of the corridor approximately 20 metres from thewestern side of the line. This event resulted in a power outage. Power was not fullyrestored to the last customer for some 48 hours. On 8 July 2016 another tree on thewestern side of the line approximately 30 metres in height and growing about20 metres from the line at the edge of the cleared corridor fell on the line (the "SecondStrike").6 There was a supply interruption of up to 21 hours whilst the necessaryrepairs were carried out. Following this event, FMNZ agreed to remove about 30 treesas a precautionary measure.4 At [25].5 At [30].6 At [36].[11] There was a further event on 6 August 2016 (the "Third Strike").7 As with theFirst and Second Strikes, the tree had been growing on the sloped land on the westernside of the line. This caused an interruption to the supply lasting up to six days whilethe necessary repairs, which were delayed as a result of a snowstorm, were carried out.After these events Unison's Chief Executive wrote to the second appellant,Roger Dickie (N.Z.) Ltd (RDNZ), claiming that as a consequence of the Second andThird Strikes Unison had suffered power outages and incurred repair costs of over$133,000. It was said that Unison would hold RDNZ "liable for damage arising fromthe two incidents on 8 July and 6 August", as the damage was: a wrongful interference with Unison's lawful and reasonable use of the landin circumstances where [RDNZ] has failed to exercise the care in themanagement of trees that a reasonably prudent forestry operator wouldexercise.[12] A further event occurred on 5 September 2018 (the "Fourth Strike"),8 after thepresent proceedings had been filed. Three further trees fell. Once again, the treeswere planted on the slope on the western side of the line. There was a supplyinterruption of approximately five hours while the necessary repairs were carried out.[13] The line provides electricity to approximately 380 customers. The four strikesresulted in outages affecting all customers served by the line. Each strike interruptedelectricity supply until Unison repaired the line.[14] Each time the trees fell as a result of what is known as "root plate failure",which occurs when the roots of a tree are insufficient to anchor it in the ground whenthe soil loosens and no longer holds up the tree, usually following adverse weatherconditions. The trees that fell were healthy trees and the strikes followed periods ofrelatively high winds and heavy rainfall. However, even with regular inspections toidentify trees at risk of falling, Nottingham Forest did not and could not identify inadvance the trees which fell in the four strikes. Having assessed the relevant expertevidence before her, the Judge said:[67] In the end, however, all that can really be taken from the expertevidence (in terms of assessing the risk of any specific tree failing) is that:7 At [39].8 At [44].(a) healthy plantation pine trees can fail in adverse weather conditions fora number of reasons (including root plate failure);(b) some risk factors are elevated where trees are grown around a clearedcorridor;(c) each tree fall event adds to the risk that newly exposed trees will fail;and(d) earlier falls of trees in a particular area might suggest that future fallsin that area are more likely.Unison's claim in the High Court[15] As noted above, Unison pleaded three causes of action, in nuisance,Rylands v Fletcher and negligence.[16] In respect of the claim in nuisance it was said that the maintenance of the forestby Nottingham Forest had created and continued to create a state of affairs thatunreasonably and substantially interfered with Unison's right to the use and enjoymentof the land over which the line is installed by:(a) allowing trees growing near the line to reach a height at which theycould fall onto it;(b) failing to ensure that the trees were inspected and managed in a waythat excluded any risk, or alternatively excluded any material risk, tothe line; and(c) allowing trees to fall onto the line.[17] Unison claimed that its loss due to the damage caused by the four strikes wasreasonably foreseeable by Nottingham Forest.[18] The Rylands v Fletcher claim alleged that one or more of the defendantspossessed and controlled the land and the trees planted on it. It was claimed that eachof the four strikes caused damage due to:(a) an escape of something harmful from the forest land, due to anon-natural use of that land; and/or(b) other interference with Unison's property rights arising from anon-natural use of the land.[19] It was again pleaded that the damage caused by the four strikes was reasonablyforeseeable by Nottingham Forest.[20] The negligence claim asserted that Nottingham Forest owed Unison a duty totake reasonable care and to exercise reasonable skill in managing and maintaining thetrees on their land in order to ensure that none fell onto or otherwise came into contactwith the line. It was then claimed that Nottingham Forest breached that duty byallowing trees growing near the line to reach a height at which they could fall upon itwhile failing to:(a) implement a regular programme of inspection to identify trees with an"elevated risk of falling" on the line;(b) prune or harvest the trees at risk of falling;(c) carry out regular trimming of the trees; and(d) identify and remedy the risks caused by the trees that ultimately fellcausing each of the four strikes.[21] The pleading alleged a continuing breach of the duty of care by allowing treesgrowing near the line to reach a height at which they could fall and damage it.[22] Unison claimed damages in the sum of $228,829, being the cost of remedyingthe damage caused by the four strikes. It also sought a declaration that the defendantswere jointly and severally liable for the costs of remedying the damage to the linecaused by each of the strikes. Injunctive relief was also sought, requiring NottinghamForest to ensure that no tree was of such a height and proximity to the line that it couldfall on it or, alternatively, to ensure that Nottingham Forest operated an inspection andmaintenance regime sufficient to ensure that no further trees would fall on the line.The High Court judgment[23] The first substantive issue dealt with by the Judge was the question of whetherUnison had a sufficient interest in or connection to the land over which the line wasinstalled to enable it to advance a claim in nuisance or Rylands v Fletcher.9 The Judgenoted that under the Electricity Act 1992, Unison as the "owner of the works" has aright to own and continue the fixing and installation of the line,10 and to maintain andupgrade it.11 In the absence of evidence bearing directly on the issue, the Judge wasprepared to assume that given the timing of the placement of the lines on the land,their construction had been authorised either under the Electric-power Boards Act1925 or the Electricity Act 1968, possibly also relying on powers in the Public WorksAct 1928.12 Further, she considered as a matter of policy that the presence of the lineswas sufficient to give Unison any necessary interest for the purposes of nuisance andRylands v Fletcher.13[24] The Judge relied on Charing Cross Electricity Supply Co v Hydraulic PowerCo,14 in which the plaintiff's electricity cables laid under the street were damaged bywater escaping from the defendant's hydraulic mains, and two judgments of this Courtin which infrastructure placed in and under streets relating to the transmission ofelectricity was held to be rateable property.15 She noted that counsel for NottinghamForest, Mr Thain, did not concede that Unison had the requisite interest in land, buthad not strenuously argued that these cases should be distinguished on the basis that9 We note that while it is generally necessary for there to be a proprietary interest to claim innuisance (see Hunter v Canary Wharf Ltd [1997] AC 655 (HL) at 688 per Lord Goff) that is notthe case for Rylands v Fletcher. The test articulated by Blackburn J was that a defendant broughtsome dangerous thing onto their land for their own purposes: Rylands v Fletcher (1866) LR 1Exch 265 at 279. A proprietary interest in land has never been a formal prerequisite for a plaintiffto bring a claim in Rylands v Fletcher: see John Murphy "The Merits of Rylands v Fletcher"(2004) 24 Ox J Leg Stud 643 at 645–650.10 Electricity Act 1992, s 22.11 Section 23(1) and (3).12 High Court judgment, above n 2, at [78].13 At [80].14 At [80], citing Charing Cross Electricity Supply Co v Hydraulic Power Co [1914] 3 KB 772 (CA).15 At [81]–[82], citing Hutt Valley Electric-Power Board v Lower Hutt City Corp [1949] NZLR 611(CA); and Telecom Auckland Ltd v Auckland City Council [1999] 1 NZLR 426 (CA).what might properly be regarded as an interest in land in a rating context should notbe so regarded for the purposes of a nuisance claim. The Judge concluded that:16(a) Unison's statutory right (once exercised) constitutes an interest in landin the form of a corporeal hereditament;(b) the owner of the utility works has the exclusive right to occupy theportion of the soil where the works lie to the exclusion of all others;(c) the interests of the owner of the surrounding land are ousted so longas the works remain in place;(d) as the statutory right confers exclusive possession, the utilitycompany's interest in the land is greater than an easement or a license;but(e) even if no interest in land can be said to exist, as a matter of policy,the existence and importance of the works must mean that Unison ispossessed of a sufficient interest to found an action inRylandsv Fletcher or nuisance.Although Nottingham Forest's appeal challenged these conclusions, Mr Walker QCadvised us at the hearing of the appeal that the issue was no longer pursued.[25] There could be no doubt that Unison's interest had been substantially interferedwith by the falling trees. The essential issue then, for the nuisance andRylands v Fletcher claims, was whether Nottingham Forest should be "strictly liable"for the resultant damage.[26] The Judge noted that in the case of an ongoing interference with a plaintiff'srelevant interest in land attributable to a defendant's unreasonable use of their land,liability in nuisance is strict.17 Further, she wrote that physical damage to a plaintiff'sland caused by a continuous or recurring emanation from a defendant's land issufficient to establish unreasonable use by a defendant.18 This was to be contrastedwith one-off incidents, which are unlikely to be the result of an unreasonable user.1916 At [83].17 At [87(a)].18 At [87(b)].19 At [87(c)].[27] The Judge also said that where a one-off incident attributable to a defendanthas resulted in damage to a plaintiff's interest, liability in negligence requires fault tobe established. However, where the one-off incident is the result of:20 an isolated escape of something dangerous (a non-natural user) which adefendant has brought onto or accumulated on his land, liability (under therule in Rylands v Fletcher) is strict.[28] The Judge considered that the statement of claim drew a distinction betweenliability for the individual tree falls (which had been pleaded in reliance onRylands v Fletcher) and liability for the "state of affairs" created by the trees onNottingham Forest's land (pleaded in nuisance).21 She thought the thinking thatunderlay this approach was that Rylands v Fletcher is generally regarded as more aptin cases of "one-off" rather than continuing interferences with a plaintiff's interest inland.22[29] The Judge recorded that in closing submissions counsel for Unison in theHigh Court, Mr May, had said that the Rylands v Fletcher aspect of the claim was notpursued. She said:23As I understand it, that change in position was predicated on the assumptionthat both the "state of affairs" and the falling trees constituted nuisancesimpliciter. Given that the individual tree falls form the foundation for thedamages claim, the concession cannot have been intended to signal anabandonment of the strict liability claim relating to those falls.[30] Notwithstanding what the Judge described as this "change of position" byUnison, she proceeded to deal with Rylands v Fletcher, noting that there would be noprejudice to Nottingham Forest in her doing so, because by the time of Mr May'sadvice, Mr Thain had already made closing submissions for Nottingham Forest whichnecessarily dealt with the Rylands v Fletcher aspect of the claim.24 She describedMr Thain's principal position as being that liability for the falling trees could not bestrict, whether in nuisance or under Rylands v Fletcher.2520 At [87(e)].21 At [88].22 At [71].23 At [72].24 At [73].25 At [73], n 29.[31] On this approach the Judge proceeded to address Nottingham Forest's liabilityfor the four strikes in terms of Rylands v Fletcher. She considered that there were anumber of aspects of the factual setting which pointed towards strict liability for thetree falls. She listed these as follows:26(a) the bulk supply of electricity (and ensuring its continuity) is a matterof significant public importance;(b) the electricity works (Unison's interest in land) pre-date the plantingof the Forest;(c) while it does not seem that the defendants receive compensation fromUnison for the ongoing presence of the works, their presence wouldlogically have influenced the price for which they purchased the land;(d) the Forest was planted at a time when there was nostatutory/regulatory obligation to ensure that trees/branches werelocated or kept at any particular distance from the works;(e) the object in planting and growing the Forest is commercial and it isimplicit in that endeavour that the trees are to reach a certain (mature)height before harvesting;(f) it was foreseeable (at the time of planting) that a number of thosemature height trees would be within falling distance of Unison'spre-existing electricity works;(g) it was foreseeable (at the time of planting) that any trees which do fallon the works are likely to do physical damage to the works and thatsuch damage would have both a physical component and aconsequential effect for Unison's customers;(h) it was known (and again was foreseeable) that healthy trees in forestscan fall from time to time, for example as a result of weather eventsand/or soil conditions, and notwithstanding that the trees themselveshave no obvious defects; and(i) at the time of planting Unison had no ability (statutory or otherwise)to require the defendants' trees to be felled or to fell them itself and(accordingly) no way of protecting the works; and(j) the subsequent promulgation of the [Electricity (Hazards from Trees)Regulations 2003] has not changed that position, because they applyonly to encroaching trees.[32] The Judge thought these considerations all pointed in favour of strict liabilityfor the tree falls. She did not consider that the cases on which Nottingham Forestrelied to argue that it should be liable only if shown to be at fault established that26 At [90] (footnotes omitted).Unison should bear the risk posed to its works by a mature forest which had been"deliberately planted around Unison's existing works for profit and in the knowledge(and intention) that they [would] ultimately grow to be within falling distance of thoseworks".27[33] The Judge held that, analysed in Rylands v Fletcher terms, the individual treefalls could be regarded as "one-off" escapes of dangerous things fromNottingham Forest's land.28 Whilst ordinarily a single healthy tree would not beregarded as dangerous, a different conclusion was warranted in light of the contextualmatters she set out, which we have quoted above. A distinction could properly bedrawn between one or a small number of trees growing in a domestic setting anda commercial forest planted around power lines. It was the "accumulation" of treesgrowing to within falling distance of the line which took the activity outside any"natural" use of the land.29[34] The Judge also held that Nottingham Forest was liable in nuisance, as thephysical damage caused to the line by "recurrently falling trees" constituted anongoing, substantial and unreasonable interference with Unison's enjoyment of itsinterest in land.30 Alternatively, the deliberate growing of many trees within fallingdistance of the line constituted an unreasonable use. While a landowner mightreasonably be expected to bear the risk posed by trees growing naturally ona neighbour's land, the present situation was not comparable with that. This was nota case where fault needed to be established, beyond the planting of the trees knowingthat they would grow to within falling distance of the line.31 Further, whether liabilitywas founded on Rylands v Fletcher or in nuisance "proper", both the damage andUnison's loss were foreseeable.32 The Judge concluded:[96] In short, it seems right in principle that strict liability should followwhere both the choice to accumulate the trees in the first place and the abilityto ensure that, in the event of a fall, they do not damage Unison's works, lieswith the defendants. Unison is powerless to protect itself and its customersfrom harm (no evidence was called, and no argument made, in terms of any27 At [91].28 At [93].29 At [93].30 At [94].31 At [94].32 At [95].ability Unison might have to insure against the risk). Damage from tree fallwas never a risk its predecessor assumed when placing the works on the land.[35] In view of these conclusions the Judge considered that the only continuingrelevance of the "state of affairs" pleading was as a foundation for quia timet injunctiverelief.33 Such relief was unavailable unless the relevant nuisance could be said to beongoing. This was unlikely in the case of Rylands v Fletcher claims because, of theirnature, they concern one-off incidents. However, in respect of the nuisance claim,the Judge considered it arguable that the existence of a well-founded fear that thenuisance constituted by the falling trees would re-occur was itself a nuisance.34The history of past falls and the evidence given in Court meant that the fear and dangerof future falls was well-founded. However, the Judge considered that on balance therisk was not sufficiently strong to justify the grant of a mandatory injunction.35[36] The Judge discussed the claim in negligence only briefly. She observed that ithad been pleaded as an alternative to Unison's "primary claims" in nuisance andRylands v Fletcher.36 She noted further that unless the relevant breach of duty couldbe said to be planting the trees within falling distance of the line (which had not beenpleaded) no fault had been established on the evidence. She thought it wasunnecessary to consider this cause of action further.37[37] In a summary, the Judge concluded that:38(a) Nottingham Forest was strictly liable to Unison for tree falls onto theline;(b) injunctive relief was not appropriate; and(c) Nottingham Forest must pay damages to Unison in the sum of$195,000.33 At [99].34 At [102].35 At [117].36 At [103].37 At [104].38 At [160].The appeal[38] Nottingham Forest's principal submission on appeal is that the Judge shouldnot have found them strictly liable for the damage caused by their trees falling ontothe line.[39] Mr Walker submitted that the growing of trees, even in a forest, is a natural useof the land and could not give rise to liability under the rule in Rylands v Fletcher.Nor could Nottingham Forest be liable in nuisance as, of itself, the existence of treesstanding within falling distance of the line was not unreasonable. Mr Walker relied oncases which were cited in the High Court as establishing that liability for tree falls isnot strict and requires fault in the management of the trees. The relevant standard forthat was the same in nuisance and negligence. He submitted that nothing in the presentcontext justified a departure from the existing case law, and because NottinghamForest was not at fault in their management of the trees, it followed that they shouldnot have been found liable.[40] Underpinning Mr Walker's submissions was the idea that trees are ubiquitous,that the tree falls occurred in a forest, that accumulations of trees whether in a forestor in a suburban setting are common and that many trees are planted in the vicinity ofproperty boundaries where they might fall and cause damage. He pointed out thatNottingham Forest had complied with the relevant regulatory regime governing treedistances from utilities,39 and had conducted regular, reasonable inspections in anendeavour to identify unhealthy trees or those at any specific risk of falling. The treefalls had occurred despite these efforts.[41] For Unison, Mr Smith QC submitted that Unison has rights proceeding fromits interest in land to be free from unreasonable interference, and the physical damageinflicted on the line was sufficient to render the interference caused by the tree fallsunreasonable. He argued that strict liability arises where a defendant has created anuisance and the taking of reasonable care from that point onwards is not relevant.39 Under the Electricity (Hazards from Trees) Regulations 2003, trees must not encroach withinprescribed distances from electrical conductors. However, the relevant distance in the present casewas only 2.5 m. Regulation 40 provides that the Regulations do not affect claims that the ownerof works may have against the owner of trees in respect of any damage caused to works by a treeowner.This was not a case where the nuisance had been created by someone other than thedefendant, where principles based on fault might be relevant.[42] As to Rylands v Fletcher, Mr Smith accepted that the continuing interferenceby tree falls and the continuing risk of that happening made strict liability in nuisancea more appropriate finding, but contended there could be no question thatNottingham Forest was also liable under the rule in Rylands v Fletcher. He submittedNottingham Forest's argument that since trees are by definition a natural thing theirmaintenance could not be a non-natural use of the land was incorrect.DiscussionNuisance[43] A private nuisance may be defined as any ongoing or recurrent activity or stateof affairs that causes a substantial and unreasonable interference with a plaintiff's landor their use or enjoyment of that land.40 However, this simple statement of the natureof the tort masks difficulties that can arise in delineating the kinds of interest protectedby it and the boundaries between private nuisance, trespass and negligence.[44] The origins of the law of private nuisance and its distinguishing characteristicswere discussed by Professor F H Newark in a well known article "The Boundaries ofNuisance" published in 1949.41 He referred to the three ways in which the lawhistorically recognised a person could be interfered with in their rights over land,observing:42Wholly to deprive a man of the opportunity of exercising his rights over landwas to disseise him, for which he might have recourse to the assize of noveldisseissin. But to trouble a man in the exercise of his rights over land withoutgoing so far as to dispossess him was a trespass or a nuisance according towhether the act was done on or off the plaintiff's land. Thus, to go on to theplaintiff's land and demolish a weir was a trespass which gave rise to theaction of trespass: to stay on your own land and demolish a weir to the hurtof the plaintiff was a nuisance for which the assize of nuisance was the properremedy. Nuisance could never be committed on the plaintiff's land: an actdone on the plaintiff's land would be disseisin or trespass according tocircumstances.40 John Murphy The Law of Nuisance (Oxford University Press, Oxford, 2010) at [1.05].41 F H Newark "The Boundaries of Nuisance" (1949) 65 LQR 480.42 At 481 (footnote omitted).[45] Thus it is that trespass to land relates to direct intrusions upon land by adefendant, whereas private nuisance deals with indirect or consequential interferenceswith land affecting a plaintiff's right to use or enjoy it.43[46] A traditional requirement for private nuisance is that there be an emanationfrom the defendant's land to that of the plaintiff.44 The concept of "emanation" wasexplained by the Supreme Court in Wu v Body Corporate as follows:45[123] Emanation is the connecting act between the activities done on adefendant's land and the alleged interference with the use and enjoyment ofthe plaintiff's land. Emanation requires a transposition of the alleged nuisance(such as noise, dirt, noxious substances or vibrations) from the defendant'sproperty to the plaintiff's property. When the alleged nuisance reaches theplaintiff's property, and substantially and unreasonably interferes with [the]plaintiff's right to use and enjoy his or her land, there will be an actionableprivate nuisance.[47] Although the emanation requirement is perhaps more apt in the context ofclaims based on odours, fumes or noise, the branches that successively fell ontoUnison's line here can be described as emanations from Nottingham Forest's landwhere the trees were growing.[48] It is possible to distinguish between different kinds of interferences with aplaintiff's land which do not involve trespassing on the land or dispossessing its owner.First, occupiers may do something on their land which interferes with the enjoymentor amenity of the neighbouring land, such as where the defendant's conduct causesnauseating or noxious smells,46 excessive amounts of smoke or noise,47 or theinfringement of a servitude such as a right to light.4843 Bill Atkin "Nuisance" in Stephen Todd (ed) Todd on Torts (8th ed, Thomson Reuters, Wellington,2019) 533 at [10.2.01].44 But see this Court's reservations on the emanation requirement in BEMA Property Investments Ltdv Body Corporate 366611 [2017] NZCA 281, [2018] 2 NZLR 514 at [57] and n 72.45 Wu v Body Corporate 366611 [2014] NZSC 137, [2015] 1 NZLR 215. In Wu, the Supreme Courtheld there was an exception to the usual requirement for there to be a "emanation". The Courtfound that liability in nuisance would have been established on the basis of the abrogation of theplaintiff's "right of access" to his unit: at [131]. However, given the Court found liabilityestablished in trespass it did not conclude on liability in nuisance: at [132].46 Murphy, above n 40, at [1.05] and n 11, citing Adams v Ursell [1913] 1 Ch 269; Wood v ConwayCorp [1914] 2 Ch 547 (CA); and Walter v Selfe (1851) 4 De G & Sm 315 (Ch).47 At [1.05] and n 12, citing Halsey v Esso Petroleum Ltd [1961] 1 WLR 683 (QB); Tetley v Chitty[1986] 1 All ER 663 (QB); Matania v National Provincial Board Bank Ltd [1936] 2 All ER 633(CA); and Andreae v Selfridge & Co Ltd [1938] Ch 1 (CA).48 At [1.05] and n 13, citing Colls v Home & Colonial Stores Ltd [1904] AC 179 (HL).[49] A second kind of case comprises interferences in which a defendant's actionson its own land result in physical damage to a plaintiff's property. Where the damageresulted from a "one-off" event, liability (at least in the nineteenth century) typicallyturned on the plaintiff demonstrating a negligent act by the defendant. Thus inVaughan v Menlove a poorly constructed haystack near the boundary of thedefendant's property caught fire, and cottages situated on the adjacent property wereburnt down.49 In the Court of Common Pleas, Tindal CJ referred to a requirement forthe defendant to exercise a standard of care "such as a man of ordinary prudence wouldobserve".50[50] Reference may also be made to Black v The Christchurch Finance Co Ltd inwhich a fire on the defendants' land destroyed crops, fences and firewood onthe plaintiff's property.51 The principal issue concerned the defendants' liability forthe mistakes of independent contractors. The Privy Council proceeded on the basisthat the claim was properly brought in negligence. So too, in Balfour v Barty-King,Lord Goddard CJ observed that:52 a person in whose house a fire is caused by negligence is liable if it spreadsto that of his neighbour, and this is true whether the negligence is his own orthat of his servant or his guest [51] These cases were discussed by Conor Gearty in his article "The Place ofPrivate Nuisance in a Modern Law of Torts".53 He observed that the references inthose cases to duty and negligence were not surprising in the context of the gradualemergence of the tort of negligence.54 He continued:55It grew out of the older, nominate, forms of tort. A negligent neighbour whodamaged your land more resembled a negligent bailee or a negligent driverthan a factory owner deliberately emitting smoke and noxious gases into theatmosphere. The negligent act was generally an isolated event: it is difficultto be continuously negligent without becoming desirous of, or at least recklessas to, the damage that is being done. ... So negligence was the chosen tort andit has remained so to this day, covering D's negligent behaviour where it49 Vaughan v Menlove (1837) 3 Bing NC 468 (Comm Pleas).50 At 475. We note that the claim was advanced in negligence.51 Black v The Christchurch Finance Co Ltd [1894] AC 48 (PC).52 Balfour v Barty-King [1957] 1 QB 496 (CA) at 504.53 Conor Gearty "The Place of Private Nuisance in a Modern Law of Torts" [1989] 48 CLJ 214.54 At 220.54 At 220.55 At 220–221 (footnotes omitted).damages his neighbour P's property, in the same way as it encompasses manyother varieties of fault.[52] The cases concerning falling trees on which Nottingham Forest relies in thepresent case can be fitted readily within such an analytical framework. Mr Walkerreferred first to Noble v Harrison in which a branch of a tree growing on thedefendant's land overhanging a highway fell, damaging the plaintiff's vehicle.56The County Court found that the defendant did not know that the branch wasdangerous, and the fall of the branch was due to a latent defect not discoverable byany reasonably careful inspection. Nevertheless, the defendant was held liable in bothRylands v Fletcher and nuisance.[53] On appeal it was held that Rylands v Fletcher did not apply. Rowlatt J heldthat growing a tree was one of the natural uses of the soil, and it made no differencewhether the tree was planted or self-sown, and for what purpose it was planted ormaintained.57 To similar effect, Wright J said:58I do not think it material to consider whether the beech was originally planted(as most boundary trees would be) or whether it grew casually. Such a tree isa usual and normal incident of the English country; it develops by slow naturalgrowth, its branches are not likely to cause danger, even if permitted to expandoutwards over the highway. Such a tree cannot be compared to a tiger,a spreading fire, or a reservoir in which a huge weight of water is artificiallyaccumulated to be kept in by dams, or noxious fumes or sewage. I see noreason whatever to apply the principle of Rylands v Fletcher to the case nowunder consideration.[54] He went on to refer to a statement made in Blake v Woolf,59 cited with approvalby the Privy Council in Rickards v Lothian,60 that there was an exception to the rulestated in Rylands v Fletcher so that:61 where a person is using his land in the ordinary way and damage happensto the adjoining property without any default or negligence on his part, noliability attaches to him.56 Noble v Harrison [1926] 2 KB 332.57 At 336.58 At 342 (footnote omitted).59 Blake v Woolf [1898] 2 QB 426.60 Rickards v Lothian [1913] AC 263 (PC) at 280.61 Noble v Harrison, above n 56, at 343, quoting Blake v Woolf, above n 59, at 428.[55] Nor was the defendant liable in nuisance. The mere fact that the branch hadbeen overhanging the highway did not make it a nuisance: it did not obstruct the freepassage of the highway, and although the branch had caused damage when it fell, thedefendant was not liable because he had not created the danger and had no knowledge,actual or able to be imputed, of its existence.62 In this respect, Rowlatt J stated thatthe defendant could be liable for a nuisance constituted by the state of his propertyonly if he had caused it, or if "by the neglect of some duty he allowed it to arise" or if,when it had arisen without his own act or default, he omitted to remedy it within areasonable time after he became aware or ought to have become aware of it.63 Further,Wright J considered there could be no liability in nuisance for a "secret andunobservable operation of nature".64[56] Mr Walker also relied on Darroch v Caroll, in which leaves falling fromoverhanging branches of a tree planted near the boundary of two residential propertieshad caused blockages of water and resultant dampness to the plaintiff's house.65A magistrate issued a mandatory injunction requiring removal of the tree from thedefendant's land. On appeal, the High Court (then the Supreme Court) varied theinjunction to require removal of the overhanging branches, as opposed to the wholetree.66 Shorland J held that permitting the branches of a tree to overhang a boundaryor encroach upon the property of a neighbour was a nuisance. However, removal ofthe encroaching branches would bring the nuisance to an end. Going further wouldrequire some other breach of duty.67 After reviewing various authorities, Shorland Jdescribed the relevant duty of a landowner in respect of trees growing on the land asbeing:68 not a duty of insuring his neighbour or users of the adjoining highwayagainst damage from his trees; but a duty to exercise the care in themanagement of his trees which a reasonably prudent landowner wouldexercise.62 At 337–338 per Rowlatt J.63 At 338.64 Noble v Harrison, above n 56, at 341.65 Darroch v Caroll [1955] NZLR 997 (SC).66 At 1002.67 At 999.68 At 1001.[57] Mr Walker also referred to Helson v Dear, in which there were claims innegligence and nuisance concerning two pine trees that fell and damageda neighbouring house.69 On the facts, the High Court considered it would have beenunreasonable to require the landowner to carry out any inspection of the trees whichappeared to be healthy, unless "something occurred that should have put her on herguard".70 While there was evidence that "a branch or two had fallen from the treesover the years", that was nothing more than could have been expected in the ordinarycourse of events and there was nothing that should have put the landowner"on enquiry".71 The Judge accepted that while an escape of something on a singleoccasion would not ordinarily be a nuisance, there was no reason in principle why itshould not be. However, to expect the defendant to have known of the dangerouscondition of the trees would have been to go beyond what was required of an "ordinaryreasonable prudent landowner".72 On this basis the cause of action in nuisance couldnot succeed. The negligence claim also failed, on the basis that the Court consideredthe relevant duty was the same.73[58] The key factual difference between these cases and the present is that here therehas been what the Judge described as a "continuous or recurring emanation" fromNottingham Forest's land causing physical damage to Unison's property as a result oftrees planted by Nottingham Forest that would grow within falling distance of theline.74 This finding underpins the proper analytical approach to liability in thecircumstances of this case. The facts show that as a result of successive falls of treesthat had grown to a height greater than their distance from the line, there was materialand substantial damage to the line, which was unable to function for its intendedpurpose of conveying electricity until costly repairs were carried out. The ongoingnature of such occurrences puts the case in a different category to those relied on byNottingham Forest whose facts engaged the law of negligence. As Gearty noted in thepassage quoted above, the cases he surveyed generally involved an isolated event, and69 Helson v Dear HC Wellington CP536/86, 25 October 1988. There had originally also been a claimin trespass but that was not pursued in the High Court.70 At 6.71 At 6.72 At 15.73 At 16.74 High Court judgment, above n 2, at [87(b)]."it is difficult to be continuously negligent without becoming desirous of, or at leastreckless as to, the damage that is being done".75[59] In order for there to be an actionable nuisance there must be an interferencewith the plaintiff's use and enjoyment of its land which is unreasonable. In assessingwhether there has been an unreasonable interference, it is necessary in each case toachieve a balance between the competing rights of the plaintiff and the defendant. Inone well known statement, Bramwell B said that the law of private nuisance isessentially a "rule of give and take, live and let live".76 In Sedleigh-Denfieldv O'Callaghan Lord Wright observed that a:77 balance has to be maintained between the right of the occupier to do whathe likes with his own, and the right of his neighbour not to be interfered with.Further, in Hunter v Canary Wharf Ltd, Lord Goff referred to "striking a balancebetween the interests of neighbours in the use of their land".78 And in SouthwarkLondon Borough Council v Tanner Lord Millett referred to balancing the conflictinginterests of adjoining owners.79[60] As Professor Bill Atkin emphasises, the critical question is always whether theinterference complained of is unreasonable because it exceeds the level that areasonable occupier, expected to tolerate the reasonable activities of a neighbour,would regard as acceptable.80 As to what constitutes a "reasonable" interference,a distinction can be drawn between the activities of a defendant that causea non-physical interference with the use and enjoyment of a plaintiff's land, andactivities that result in non-trivial, physical damage to neighbouring land.81 Where,as in this case, there has been ongoing and substantial physical damage to a plaintiff'sproperty, that will ordinarily be sufficient, without more, to establish that theinterference is unreasonable.8275 Gearty, above n 53, at 220.76 Bamford v Turnley (1862) 3 B&S 66 (Exch) at 83.77 Sedleigh-Denfield v O'Callaghan [1940] AC 880 (HL) at 903.78 Hunter v Canary Wharf Ltd [1997] AC 655 (HL) at 693.79 Southwark London Borough Council v Tanner [2001] 1 AC 1 (HL) at 20.80 Atkin, above n 43, at [10.2.03].81 St Helen's Smelting Co v Tipping [1865] 11 HLC 642 (HL) at 650; Halsey v Esso Petroleum CoLtd [1961] 1 WLR 683 (QB) at 691; and Clearlite Holdings Ltd v Auckland City Corp [1976] 2NZLR 729 (SC) at 740.82 Clearlite Holdings Ltd v Auckland City Corp, above n 81, at 740.[61] We accept that there is a social utility in the growing of trees for forestrypurposes, as Mr Walker submitted. However, as Mr Smith countered, there is also ofcourse a very obvious utility in the provision and maintenance of lines for the supplyof electricity. But the case does not call for a comparative weighting of one activityagainst the other. The question here is whether Nottingham Forest's maintenance oftrees planted adjacent to Unison's line, close enough to damage it when from time totime they fell, unreasonably interfered with Unison's right to enjoy its property interestin the line.[62] Given the inevitability (demonstrated by earlier events) of tree falls in andfollowing bad weather conditions, we have no doubt that it was unreasonable forNottingham Forest to allow the trees to grow to the height at which they would causephysical damage to Unison's line when they fell. In doing so, Nottingham Forestcreated a state of affairs on its land that caused an unreasonable and continuinginterference with Unison's line.[63] A party responsible for creating a state of affairs that unreasonably interfereswith a neighbouring property will be strictly liable for the consequences in the sensethat it will not be a defence to show that all reasonable precautions were taken toprevent the activity from causing an unreasonable interference. As was said byLord Goff in Cambridge Water Co v Eastern Counties Leather plc, where thedefendant has been responsible for the creation of a nuisance liability is strict, although"that liability has been kept under control by the principle of reasonable user".83 In theresult:84 if the user is reasonable, the defendant will not be liable for consequentharm to his neighbour's enjoyment of his land; but if the user is not reasonable,the defendant will be liable, even though he may have exercised reasonablecare and skill to avoid it.[64] The principle was also succinctly stated by Lord Hoffmann in Transco plc vStockport Metropolitan Borough Council.85 He observed:8683 Cambridge Water Co v Eastern Counties Leather plc [1994] AC 264 (HL) at 299.84 At 299.85 Transco plc v Stockport Metropolitan Borough Council [2003] UKHL 61, [2004] 2 AC 1.86 At [26].Liability in nuisance is strict in the sense that one has no right to carry on anactivity which unreasonably interferes with a neighbour's use of land merelybecause one is doing it with all reasonable care. If it cannot be done withoutcausing an unreasonable interference, it cannot be done at all.[65] He went on to state that a defendant's liability to pay damages is "limited todamage which was reasonably foreseeable".87 Such foreseeability does not in ourview relate to the specific instance of damage, but to the kind of damage that hasoccurred as a consequence of the acts that gave rise to the interference. Thatconclusion is consistent with the principles concerning foreseeability of damagediscussed in Cambridge Water Co. After observing that taking all reasonable care willnot of itself exonerate a defendant who has created a nuisance from liability(the relevant control mechanism being the principle of reasonable user), Lord Goffcontinued:88But it by no means follows that the defendant should be held liable for damageof a type which he could not reasonably foresee; and the development of thelaw of negligence in the past 60 years points strongly towards a requirementthat such foreseeability should be a prerequisite of liability in damages fornuisance, as it is of liability in negligence.[66] This was followed by a brief reference to Lord Reid's judgment in The WagonMound (No 2)89 and the conclusion that foreseeability of harm is a prerequisite of therecovery of damages in private nuisance.90 Lord Goff characterised Lord Reid'sdiscussion of foreseeability as relating to remoteness of damage.91 We note that,consistently with these cases, in Hamilton v Papakura District Council this Court heldthat in nuisance, as with Rylands v Fletcher, foreseeability of the type of damage thatoccurred is a prerequisite to the recovery of damages.92[67] It is no answer to this to say, as Nottingham Forest does here, that it was notpossible to predict which if any trees would in fact fall in the extreme weatherconditions that occurred. As noted earlier, the four strikes which form the basis ofUnison's claim came after earlier events in which trees fell causing power outages in87 At [26].88 Cambridge Water Co v Eastern Counties Leather plc, above n 83, at 300 (emphasis added).89 Transco plc v Stockport Metropolitan Borough Council, above n 85, at [26], citing OverseasTankship (U.K.) Ltd v Miller Steamship Co Pty [1967] 1 AC 617 (PC) [The Wagon Mound (No 2)].90 At [26], citing The Wagon Mound (No 2), above n 89, at 640.91 Cambridge Water Co v Eastern Counties Leather plc, above n 83, at 301.92 Hamilton v Papakura District Council [2000] 1 NZLR 265 (CA) at [75]–[76].December 2010, July 2011 and September 2013. The 11kV line was affected by treefalls in April 2012 and January and November 2014. Accordingly, it was obvious thatthere was a real possibility that ongoing tree falls causing damage to the line wouldoccur. And while it was not possible to predict which individual tree might fall, thereasonable action for Nottingham Forest to have taken was to remove the trees whichwould cause damage to the line if they fell.[68] In the circumstances, we have no doubt that the four strikes for which Unisonsought damages were incidents involving damage of a type which was plainlyforeseeable. Given our earlier conclusion concerning unreasonable interference, wetherefore think the Judge was right to find Nottingham Forest liable to pay damagesin nuisance given the finding, now not challenged, that Unison had a sufficientproprietary interest to sue.[69] We do not read compliance with the Electricity (Hazards from Trees)Regulations 2003 as an indication that the activity of Nottingham Forest wasreasonable. Nottingham Forest accepted that the Judge correctly held that theRegulations (and in particular reg 4093) do not remove common law liability of theowner of trees to the owner of works (defined in accordance with the Electricity Act94)for damage caused by tree falls. However, Nottingham Forest's submission was thatthe reference in reg 40 to damage to works by a "tree owner" (as opposed to "trees")recognises that there must be fault on the part of the tree owner. We doubt that theRegulations were intended to have any impact on common law liability other than topreserve it. In any event, at common law, unreasonable user can be inferred from thefact that ongoing physical damage is caused by the impugned activity.[70] We note that different approaches have been taken to the issue of whetherforeseeability of the risk of harm is a necessary ingredient of liability in nuisance.95In the United Kingdom, the Court of Appeal in Northumbrian Water Ltd v Sir RobertMcAlpine Ltd held that the event which causes the interference with the plaintiff's93 See n 39 above.94 Electricity Act, s 2.95 See the discussion in Maria Hook "Strict liability in nuisance — a fork in the road" [2021] NZLJ136.property must be reasonably foreseeable by the defendant.96 Thus the respondent wasnot liable for damage caused by concrete which had leaked into a private sewer, as theCourt held there was no reason to think the respondent should have foreseen thepossibility that concrete would escape from its development site to neighbouringproperty.97 In PEX International Pte Ltd v Lim Seng Chye, however, the SingaporeCourt of Appeal declined to follow that approach, preferring to rely on the concept ofreasonable user to control liability in nuisance.98 Foreseeability of the kind of harm,however, remained relevant to whether damages could be recovered.[71] It is not necessary in this case to choose between these different approaches.On the facts, both the kind of damage and the tree falls which caused it were plainlyforeseeable.Rylands v Fletcher[72] The "rule" in Rylands v Fletcher is based on the statement made byBlackburn J in that case:99We think that the true rule of law is, that the person who for his own purposesbrings on his lands and collects and keeps there anything likely to do mischiefif it escapes, must keep it in at his peril, and, if he does not do so, is primafacie answerable for all the damage which is the natural consequence of itsescape.[73] The decision was affirmed in the House of Lords, but Lord Cairns LC addedthe gloss that the rule was restricted to circumstances where the defendant had made"a non-natural use" of the land.100 Where the rule applies, liability is strict and it isnot necessary for the plaintiff to prove negligence by the defendant.[74] The rule was abolished in Australia by the decision of the High Court inBurnie Port Authority v General Jones Pty Ltd.101 But it remains part of the law of96 Northumbrian Water Ltd v Sir Robert McAlpine Ltd [2014] EWCA Civ 685, [2014] All ER (D)157.97 At [19] and [25].98 PEX International Pte Ltd v Lim Seng Chye [2019] SGCA 82 at [53] and [55].99 Rylands v Fletcher, above n 9, at 279, as affirmed by the House of Lords in Rylands v Fletcher(1868) LR 3 HL 330 (HL).100 Rylands v Fletcher, above n 99, at 339.101 Burnie Port Authority v General Jones Pty Ltd (1994) 179 CLR 520 at 556–557, holding that therule in Rylands v Fletcher was absorbed by the principles of ordinary negligence.England and Wales, as confirmed in Cambridge Water and Transco,102 and as part ofNew Zealand's common law, as confirmed by this Court's decision in Hamiltonv Papakura District Council.103[75] Although the real nature of the cause of action remains controversial,the current orthodoxy, exemplified by Cambridge Water Co and Transco, sees Rylandsv Fletcher as a branch or "offshoot" of the law of nuisance, dealing with damagecaused by isolated escapes of dangerous things from land. For example, in CambridgeWater Co Lord Goff described the rule as "essentially concerned with an extension ofthe law of nuisance to cases of isolated escape".104[76] The justification and rationale for the rule is seen in the requirement that thedefendant has been engaging in a particularly dangerous activity. This was explainedin an article by Frederick Pollock, on the basis that:105 certain things are a source of extraordinary risk, and a man who exposeshis neighbour to such a risk is held to insure his neighbour against anyconsequent harm not due to some cause beyond human foresight and control.[77] It is clear that the article of Professor Newark ("The Boundaries of Nuisance"),from which we have quoted above, has also been influential.106 It was referencedextensively by Lord Goff in Cambridge Water Co, and referred to by Lords Bingham,Hoffmann and Hobhouse in Transco. In the latter case, Lord Hoffmann said:107[27] Rylands v Fletcher was therefore an innovation in being the first clearimposition of liability for damage caused by an escape which was not allegedto be either intended or reasonably foreseeable. I think that this is whatProfessor Newark meant when he said in his celebrated article ("TheBoundaries of Nuisance" ) that the novelty in Rylands v Fletcher was thedecision that "an isolated escape is actionable". That is not because a singledeluge is less of a nuisance than a steady trickle, but because repeated escapessuch as the discharge of water in the mining cases and the discharge of102 Cambridge Water Co v Eastern Counties Leather plc, above n 83; and Transco plc v StockportMetropolitan Borough Council, above n 85. But not Scotland: see RHM Bakeries (Scotland) Ltdv Strathclyde Regional Council 1985 SC 17 (HL) at 41.103 Hamilton v Papakura District Council, above n 92. This case resolved uncertainty about whetherNew Zealand courts would follow Cambridge Water Co v Eastern Counties Leather plc or BurniePort Authority v General Jones Pty Ltd, following the judgment in Autex Industries Ltd v AucklandCity Council [2000] NZAR 324 (CA).104 Cambridge Water Co v Eastern Counties Leather plc, above n 83, at 304.105 Frederick Pollock "Duties of Insuring Safety: The Rule in Rylands v Fletcher" (1886) 2 LQR 52.106 Newark, above n 41.107 Transco plc v Stockport Metropolitan Borough Council, above n 85.chemicals in the factory cases do not raise any question about whether theescape was reasonably foreseeable. If the defendant does not know what heis doing, the plaintiff will certainly tell him. It is the single escape which raisesthe question of whether or not it was reasonably foreseeable and, if not,whether the defendant should nevertheless be liable. Rylands v Fletcherdecided that he should.[78] The idea that Rylands v Fletcher is an offshoot of the tort of private nuisancehas been comprehensively criticised by Donal Nolan who argues that it is based upona misreading of the case itself.108 However, for present purposes, and in the absenceof any argument that we should not do so, we proceed on the basis that the current lawis as set out in Cambridge Water Co and Transco.[79] We consider the key issue in this part of the case is whetherNottingham Forest's activity in maintaining the forest can be described as the naturalor ordinary use of the land. Just as the concept of reasonable user limits the extent ofliability in nuisance, the concept of natural or ordinary use of the defendant's land hasbeen used to control liability in Rylands v Fletcher.109 The classic expression of thisprinciple remains that by Lord Moulton in Rickards v Lothian:110It is not every use to which land is put that brings into play that principle.It must be some special use bringing with it increased dangers to others, andmust not merely be the ordinary use of the land or such a use as is proper forthe general benefit of the community.[80] In Transco, Lord Bingham said that no ingredient of Rylands v Fletcher hadprovoked more discussion than the requirement expressed in Blackburn J's judgmentthat the defendant should have brought something onto its land something which was"not naturally there", which was elaborated on by Lord Cairns on appeal when hereferred to a "non-natural use" of land.111 After referring to various articles in whichthe concept of been discussed, Lord Bingham said:112I think it clear that ordinary user is a preferable test to natural user, making itclear that the rule in Rylands v Fletcher is engaged only where the defendant'suse is shown to be extraordinary and unusual. This is not a test to be inflexiblyapplied: a use may be extraordinary and unusual at one time or in one placebut not so at another time or in another place I also doubt whether a test of108 Donal Nolan "The Distinctiveness of Rylands v Fletcher" (2005) 121 LQR 421.109 Cambridge Water Co v Eastern Counties Leather plc, above n 83, at 299, per Lord Goff.110 Rickards v Lothian, above n 60, at 280.111 Transco plc v Stockport Metropolitan Borough Council, above n 85, at [11].112 At [11].reasonable user is helpful, since a user may well be quite out of the ordinarybut not unreasonable [81] As noted earlier, in this case the Judge considered that the individual tree fallscould be regarded as "one-off" escapes of dangerous things from Nottingham Forest'sland.113 She considered the accumulation of trees took Nottingham Forest's use of theland use outside any concept of "natural" use.[82] We are unable to agree with that approach. In our view, the planting andgrowing of trees for the purposes of forestry cannot be regarded as anything other thanan ordinary use of rural land. We would not describe it as a "special use bringing withit increased danger to others".114 Still less can it be described as "extraordinary andunusual" in terms of Lord Bingham's formulation in Transco.115 The activity is afterall widespread in rural New Zealand and permitted by relevant resource managementplans.[83] Further, when they are planted, trees clearly cannot be regarded as dangerous.It is only when the trees in this case grew to a height greater than their distance fromthe line that there was a risk that they would fall and cause damage. The question ofwhether there is an ordinary use of land cannot properly be approached on the basisthat planting and maintaining trees can be considered an ordinary activity except whenthey have grown above a certain height so that they pose a danger because of theirproximity to a power line. That reasoning would imply that maintenance of trees thatwere younger or located at a greater distance from the line is an ordinary use of theland, while maintaining taller trees is not. The issue of whether an activity can bedescribed as an ordinary use of land cannot depend on such fine distinctions. We addthat such an approach would rob the key limitation mechanism of Rylands v Fletcherof its intended effect.[84] The focus must be on the use being made by the defendant of its land at thetime of the tree fall, that is, the "escape". The approach in the High Court effectivelyelides the question of whether the land use is an ordinary one with the events that113 High Court judgment, above n 2, at [93].114 Rickards v Lothian, above n 60, at 280.115 Transco plc v Stockport Metropolitan Borough Council, above n 85, at [11].resulted in the damage. These are distinct concepts. If they are not kept distinct anyactivity which involves actions taken by a landowner resulting in damage to aneighbouring property might be brought within the ambit of Rylands v Fletcher.[85] For these reasons we do not consider the Judge was correct to holdNottingham Forest liable in Rylands v Fletcher. In the circumstances it is unnecessaryto resolve the issue raised by Nottingham Forest that the Judge should not have heldthem liable on this cause of action because of the stance adopted by their counsel inhis closing argument in the High Court.[86] However, our conclusion that the Judge was right to uphold the claim innuisance means that the appeal must be dismissed.The cross-appeal[87] Unison filed a combined notice of cross-appeal and memorandum supportingthe High Court judgment on other grounds. Two key issues were raised: first, whetherthe Judge erred in declining to give injunctive relief and secondly, whether NottinghamForest was liable in negligence.[88] As matters transpired, Mr Walker confirmed at the hearing that the treesstanding within falling distance of the line had been removed between 31 August and4 September 2020. That was subsequently confirmed by an affidavit of arepresentative of Nottingham Forest. In the circumstances, Mr Smith indicated thatthe part of the cross-appeal seeking injunctive relief was abandoned.[89] That left as the only issue to be argued the question of whether the Judge shouldhave held Nottingham Forest liable in negligence. But that issue was conditionally tobe addressed if Nottingham Forest was "not liable in nuisance or Rylands v Fletcher".That is consistent with the Judge's observation, presumably reflecting the approachtaken at the hearing in the High Court that negligence had been pleaded as"an alternative to Unison's primary claims in nuisance and Rylands v Fletcher".116116 High Court judgment, above n 2, at [103].[90] Consequently, although we heard argument on the issue, the question ofliability in negligence does not now call for a decision. We think it is preferable inany event that it not be addressed since the Judge dealt with it only very briefly and inconclusory terms:[103] Negligence was pleaded as an alternative to Unison's primary claimsin nuisance and Rylands v Fletcher. It was not the preferred cause of actionnot just because it requires fault to be established but also because injunctiverelief is not an available remedy. And unless the relevant breach of duty couldbe said to be planting the trees within falling distance of the Line in the firstplace (which is not pleaded and as to the merits of which I do not comment)no fault is established on the evidence here.[91] Mr Smith challenged this conclusion of the Judge, pointing out that the dutiesalleged to have been breached in the statement of claim included a duty to exercisereasonable skill in managing and maintaining the trees in order to ensure that none fellonto, or otherwise came into contact with, the line. He argued that this was a wideenough allegation to embrace all phases of the forestry process including planting, butalso managing, maintaining and harvesting trees. He contended this adequatelyexpressed a duty to ensure that trees, given their growth and height, were not too closeto the line. He added that even if the duty were defined more narrowly as a failure toidentify and remove trees at an elevated risk of falling, Nottingham Forest had notdone so.[92] The difficulty is that the Judge found that no fault was established on theevidence. This was a finding open to her. There is not in fact a specific allegation thatthe trees had initially been planted too close to the line, and we do not accept thepleading was sufficient to embrace that. Any breach of duty must notionally havearisen years later, and the Judge found that it was not possible to predict individualtree falls.117[93] In all the circumstances we consider the appropriate course to follow is todismiss the cross-appeal.117 At [106].Result[94] The appeal is dismissed.[95] The cross-appeal is also dismissed.[96] The appellants must pay the respondent costs on the appeal, calculated for astandard appeal on a band A basis, and usual disbursements. We certify for twocounsel.[97] The respondent must pay the appellants costs on the cross-appeal on the samebasis, and usual disbursements. We certify for two counsel.Solicitors:DLA Piper, Wellington for AppellantsLuke Cunningham Clere, Wellington for Respondent