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Legislation Cited: Conveyancing Act 1919 (NSW)

Cases Cited: Gales Holdings Pty Ltd v Tweed Shire Council (2013) 85 NSWLR 514; [2013] NSWCA 382
Gartner v Kidman (1962) 108 CLR 12; [1962] HCA 27

Category: Principal judgment

Parties: Charbel Tannous (Plaintiff)
Manyun Tang (First Defendant)
Ya Jun Tang (Second Defendant)

Representation: Counsel:
Mr M Young SC (Plaintiff)
Mr M Luitingh (Defendants)
Solicitors:
Finn Roache Lawyers (Plaintiff)
Jane Button & Associates Pty Ltd (Defendants)

File Number(s): 2023/00083272

Publication restriction: Nil

JUDGMENT

1. The plaintiff, Mr Charbel Tannous, is the owner of a residential property in a suburb in south-western Sydney. Mr Tannous’ property is No 4 in the street and I will refer to it as No 4. The defendants, Mr Manyun Tang and Ms Ya Jun Tang (“the Tangs”), own a residential property which shares a boundary with No 4. Mr and Ms Tang’s property is No 2B in the street, and I will refer to it as No 2B.

2. The improvements on No 4 include a dwelling (one of a duplex) with an outdoor swimming pool and paved area in the backyard. Mr Tannous was the owner of No 4 when the dwelling and the swimming pool were constructed in 2016 and early 2017.

3. No 2B sits behind No 2A and takes access to the street pursuant to a right of way over a strip of No 2A’s land along the western boundary, which is the boundary with No 4.

4. A drainage easement runs along the western boundary of No 2A, in the right of way. The easement contains a stormwater pipe and other stormwater infrastructure.

5. No 2B is higher, topographically, than No 4.

6. In his claim, Mr Tannous alleges that water flowed in significant quantities into the back yard of No 4 from No 2B on many occasions from 20 March 2021 to the date of the filing of the statement of claim (13 March 2023). It is alleged that the intrusion of water into No 4 constitutes a private nuisance. It is further alleged that the intrusion of water into No 4 from No 2B was caused by the failure of the Tangs to ensure that the stormwater system complies with the drainage plan approved by the Council and the failure by the Tangs to maintain the stormwater system of No 2B. It is alleged that the water which came into No 4 from No 2B caused damage to the paving around the swimming pool, the pool and the pool equipment on No 4. It is further alleged that Mr Tannous has suffered a diminution in the enjoyment of his property on account of the water ingress.

7. In their defence, the Tangs deny liability for the water ingress into No 4.

8. The Tangs plead that Mr Tannous has caused the water ingress into No 4 by removing a kerb that was on a section of the boundary between the properties, by “deeply excavating” alongside the driveway on No 4 and by failing to provide an adequate retaining wall along the boundary in breach of DA 17/2016 Drawing 15164-01.

9. The Tangs filed a cross-claim on 21 July 2023, an amended cross-claim on 12 May 2025, after the hearing, and a further amended statement of cross-claim on 2 June 2025. Mr Tannous did not object to the further amended statement of cross-claim being substituted, though he opposes the orders sought. I will refer to the further amended statement of cross-claim as the cross-claim.

10. The Tangs seek, in the cross-claim, damages for loss of support to No 2B under s 177 of the Conveyancing Act 1919 (NSW).

11. In the hearing, in Mr Tannous’ case, oral evidence was given by Mr Tannous, Ms Mariat Boulos and Mr Ali Taychouri. Mr Tannous also relied on the evidence of Mr Gordon Xue, a building consultant which was given concurrently with the evidence of Mr Gregory James, the building expert in the Tangs’ case. Mr Tannous also relied on the evidence of Mr Malcolm Smith, a stormwater engineer, and Mr Leigh Appleyard, a structural engineer, given concurrently with the evidence of Mr Milton Webster, a structural engineer, and Mr David Willows, a geotechnical engineer, both of whom gave evidence in the Tangs’ case. Mr Tang and Mr Oloapu Tato also gave oral evidence.

History

12. In about 1995, No 2 was subdivided into No 2A (also sometimes referred to as No 2) (Lot 162 DP 849976), the southern, street-facing lot, and No 2B (Lot 161 DP 849976), the northern lot behind No 2A.

13. According to the title search of No 2B, at all material times it has had the benefit of the following rights over portion of No 2A:

14. an easement to drain water, 1.25 metres wide, along the western boundary with No 4,

15. a right of carriageway (“right of way”), 3 metres wide in parts and wider in an area next to No 2B, also along the western boundary with No 4,

16. an easement for services, 3 metres wide and wider in parts.

17. The Tangs purchased No 2B in 1996. In his affidavit of 12 April 2024, Mr Tang says that the driveway along the right of way had been constructed by the time that he and his wife purchased No 2B. The allotment they purchased, however, was vacant. In 1997, the Tangs engaged Masterton Homes to build a single storey brick home and stormwater system on No 2B. The stormwater disposal system constructed for the house was connected to the existing 150mm PVC stormwater pipe in the easement, Mr Tang says, in his affidavit.

18. The Tangs moved into their new house on No 2B when it was completed, probably in 1998.

19. I note the evidence of Mr Tang, in his affidavit of 12 April 2024, that, in 1999:

…I had a concrete kerb with downturn built along the existing fence on the boundary of Lot 162 (Tang Land) and the neighbouring 4 [street, suburb]. The kerb is in the driveway area, Section A to B in Annexure 1 of Annexure GT-5. This kerb is part of the stormwater drainage system for the Tang Land and prevented the surface flow to flow down to the western downstream properties. I refer to Annexure 3 of Annexure GT-5, being photographs showing the kerb.

17. Mr Tang asserts, in his affidavit of 12 April 2024 that “the concrete retaining wall and kerb…that I had installed in 1999 was cut off” during the building work on No 4. Mr Tang does not say that he witnessed this occurring. He does not say when he noticed it. He and his family moved out of No 2B in 2004 or 2005. Since then, he has rented out the property and visits several times per year.

18. In his affidavit of 28 January 2025, Mr Tang clarifies that what he meant in his previous affidavit was that he built the concrete kerb himself. He said that he first “cut and removed the slab edge by using a contractor”. He then excavated about 40cm and constructed a footing in the first concrete pour, the downturn in the second concrete pour, the concrete slab in the third concrete pour and a kerb in the fourth concrete pour. He said that the structure extended for approximately 12 metres along the boundary. He provided a diagram of the works, which was not consistent with what the expert engineers viewed on the site, in that the downturn was further inset back towards No 2B than the diagram showed, and no kerb is present on site. The experts saw that at least part of the face of the concrete had been sawcut at a location behind the fence erected for Mr Tannous on the boundary. Mr Smith included a photograph of the sawcut concrete in his report at CB p 545. Rather than being associated with any removal of the kerb, it seems the sawcuts were part of Mr Tang’s construction of the downturn. Mr Tang agreed with this.

19. The photograph in Mr Tang’s affidavit of 28 January 2025, which, he says shows the concrete kerb, shows a kerb which looks very like a line of bricks.

20. There is no sign on the remaining concrete of any kerb being severed from the concrete slab.

21. The fence built for No 4 is located next to the concrete slab with the downturn and not on top of it. There would have been no benefit to No 4 for the contractor or Mr Tannous to remove any kerb. Had a kerb been present, it would not have impeded the installation of the fence.

22. Both Mr Tannous and Ms Boulos say that the kerb on the boundary is the same now as it was when they purchased No 4 in 2016. In his affidavit, Mr Tannous denied that any part of the kerb was removed during the building works on No 4.

23. Mr Ali Taychouri purchased No 2A in 1998 and still owns it. He swore an affidavit on 9 September 2024. Mr Taychouri says that he noticed the kerb on the boundary with No 4 when he purchased No 2A and that the kerb remains the same. No part of it has been removed.

24. The Tangs leased No 2B to tenants from 2005, but Mr Tang visited the property at least once a year to perform maintenance and repair tasks.

25. Mr Oloapu Tato has been the tenant of No 2B since 2012. Mr Tato swore an affidavit on 18 August 2024. Mr Tato says that part of the fence along the west side of No 2B was demolished during the development of No 4 and replaced with a pale green metal fence. Mr Tato says that he noticed that “the concrete kerb was missing” after the installation of the new fence. He says that he did not remove the kerb. In cross-examination, he was unable to say how high the kerb in that location was. Mr Tato’s evidence was that he thought that the “new metal fence” installed during the construction on No 4 was “pushed in towards the side of 2B… to sit at the position where the kerb used to be”. This cannot be correct. The fence sits alongside the concrete slab between Points A and B, and not on top of the concrete slab. For Mr Tato to be correct, the kerb would have had to have been on part of the old concrete slab which protruded into No 4, and which was cut off in order for Mr Tang to build the downturn.

26. A number of possibilities exist with respect to the fate of the kerb on the land at No 4 between Points A and B. It may never have existed, in the form of a concrete kerb. Had it been constructed by means of concrete poured on top of the slab, its removal would have left marks. It may have been a line of bricks removed at any time between the photograph taken in 2010 (and included in Mr Tang’s affidavit of 28 January 2025) and 2021, when the water ingress was first reported into No 4. If that is what occurred, the removal could have been undertaken by any number of people, for any number of reasons. It has not been established, on the balance of probabilities, that any such removal occurred at the direction of Mr Tannous or anyone associated with the construction works on No 4. The expression of a belief to the contrary by lay and expert witnesses is speculation and without an evidentiary basis.

27. Mr Webster initially believed that the concrete downturn of the concrete slab on No 2B between Points A and B had been cut away, so that there was no barrier to water seeping into No 4 from under the slab. However, Mr Webster was shown, at the joint conclave meeting on the property, that the slab does have a downturn, somewhat further back into the No 2B side of the boundary than he had anticipated. Mr Webster came to agree with Mr Appleyard and Mr Smith that the “great majority” of the flow of water into No 4 is an overland flow and not a subterranean flow (T 6 May 2025 p 147).

28. Mr Smith, Mr Appleyard and Mr Webster agreed that the concrete slab on No 2B between the southwest corner of No 2B and the point just north of Pit 1, shown on the plan at CB p 288, has a concrete downturn and projects into No 4. All of the engineers accepted that the account Mr Tang gives of building a concrete kerb in this location is inconsistent with the presence and appearance of the slab in this location and is, therefore, mistaken. I accept the evidence of Mr Smith, Mr Appleyard and Mr Webster. I am unable to find, on the balance of probabilities, that Mr Tannous or his builder removed a concrete kerb from any part of the boundary between No 2B and No 4.

29. Mr Tang says that, in 2017, the single storey house on No 4 was demolished.

30. A two-storey duplex was then built on the land at No 4 and became No 4 and No 4B.

31. Mr Tang says that, in late 2001, single brick retaining walls were built on No 4 along the brown metal fence then in place on the boundary with No 2B and the easement. Mr Tannous, in his affidavit of 12 April 2024, says that a retaining wall was built along the boundary between No 4 on one side and No 2 and No 2B on the other when the duplex was built on No 4. I find that a single brick wall was built along the boundary as part of the construction work on No 4, but the expert engineers agree that it is constructed from extruded bricks and does not serve as a proper retaining wall.

32. Mr Willows, in his report of 27 June 2024, said that he believed that it was necessary for Mr Tannous to build a retaining wall on No 4, next to the swimming pool area, in order to retain the soil on No 2B on account of a change to the levels between the two properties that he understood to have been brought about during the construction works on No 4. Mr Webster, in his report of 5 June 2024, also indicated that he believed that the single brick wall installed under the new fence on the boundary was not an adequate retaining wall.

33. Subsequently, in a document prepared by him on 4 May 2025, Mr Webster conceded that a comparison of the Dancom Builders Pty Ltd survey drawing of 28 August 2015 with the Ross Robinson Consulting Survey drawing dated 12 December 2023 shows that the works on No 4 did not cause any significant change in levels between the two properties. Mr Webster cavilled with the location of the data points on the Dancom Builders Pty Ltd survey because they are up to 1 metre from the boundary, but I reject that reservation. Mr Webster also advanced a theory based upon the photograph prior to 2005 which is included in his report, and which shows a door lying on its side by the boundary next to the carport on No 2B. Mr Webster assumes that the door is lying on the ground, assumes its width and extrapolates a view that No 4 has been lowered since the photograph was taken. I prefer the evidence on the survey plans to Mr Webster’s evidence. Mr Appleyard relied on the survey plans and his opinion was that there has been no significant change in the levels between the two properties. I accept that evidence. I find that the finished levels on No 4 were comparable to the levels prior to the building works. I also find that there was a downturn on the concrete slab on No 2B adjacent to the boundary. In these circumstances, the lack of an adequate retaining wall under the new boundary fence is not significant in the context of the claim. It is clear that about 90% of the water flowing onto No 4 from No 2B is flowing overland.

34. Mr Tannous gives a detailed account of the incidents of water ingress into No 4 from No 2B in his affidavit.

35. In his affidavit, Mr Tang says that he received a complaint from Mr Tannous about the stormwater and dirt flowing into No 4 and entering the swimming pool on No 4 from No 2B in 2021, after heavy rain. Mr Tang and Mr Tannous met and had a conversation about the water ingress into No 2B but did not resolve the issue.

36. Mr Taychouri also saw stormwater overflowing from the stormwater drain in the easement and entering No 4 in early 2021. He says he has seen it happen again on many occasions, when it rains. Ms Boulos, in her affidavit, says that, from March 2021, she has seen numerous instances of water coming into No 4 from No 2B.

The Claim

Private Nuisance

37. In Gales Holdings Pty Ltd v Tweed Shire Council (2013) 85 NSWLR 514, (‘Gales Holdings’) Emmett J summarised the elements of the tort of nuisance at [131] – [133]:

131 A nuisance is either a continuous or recurrent state of affairs. An occupier of land will be liable for continuing a nuisance if, with knowledge or presumed knowledge of the state of affairs, the occupier fails to take reasonable steps to bring it to an end despite having had ample time to do so (Hargrave v Goldman [1963] HCA 56; 110 CLR 40 at 59-61). There will be nuisance if a state of affairs created, adopted or continued by an owner or occupier of land harms another person’s enjoyment of land occupied or owned by that other person, unless the first person’s conduct involves no more than the reasonable and convenient use of its own land (Hargrave v Goldman at 62).

132 That is to say, nuisance is a wrongful interference with another’s enjoyment of land by the use of other land occupied or owned by the alleged wrongdoer. However, an owner or occupier of land is not an insurer. There must be more than mere harm being done to another’s enjoyment of land. The harm must be caused by the alleged wrongdoer’s use of its own land. The word use connotes that a degree of personal responsibility is usually required, even though a deliberate or negligent act is not. A deliberate or negligent act will however be sufficient. A balance must be maintained between an owner or occupier’s right to do what it likes with its land and a neighbour’s right not to be interfered with. The proper test to apply in most cases is what is reasonable, according to the ordinary usages of a particular society. While negligence is not essential, fault of some kind is almost always necessary (Elston v Dore [1982] HCA 71; 149 CLR 480 at 487-488).

133 The flow of water can give rise to nuisance. There is a difference between the flow of surface waters and the flow of natural watercourses. Riparian rights attach to the flow of natural watercourses such as rivers or streams, but not to the flow of surface waters.

38. In Gartner v Kidman (1962) 108 CLR 12; [1962] HCA 27 (‘Gartner’) Windeyer J, with whom Dixon CJ and Tiernan J (in essence) agreed, summarised the law concerning the flow of surface water from the land of one person to the land of that person’s neighbour, with the qualifications that “the propositions are general”, the propositions do not apply to any kind of watercourse and they concern only surface water which came naturally upon the land from which it flows, at [50] – [59]:

50. 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: - (at p48)

51. The higher proprietor: He is not liable merely because surface water flows naturally from his land on to lower land. (at p48)

52. He may be liable if such water is caused to flow in a more concentrated form than it naturally would. (at p48)

53. 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. (at p48)

54. 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. (at p48)

55. 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. (at p48)

56. The above statements concerning the concentration of surface waters relate to cases when the increased flow results from work done when the higher land and the lower land were held by separate proprietors. Different considerations apply when the lower land receives a concentrated flow as the result of work which was done when it and the higher land were in the same ownership and possession. (at p48)

57. 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. (at p49)

58. Although he has no action against the higher proprietor because of the natural unconcentrated flow of water from his land, he is not bound to receive it. He may put up barriers and pen it back, notwithstanding that doing so damages the upper proprietor’s land, at all events if he uses reasonable care and skill and does no more than is reasonably necessary to protect his enjoyment of his own land. But he must not act for the purpose of injuring his neighbour. It is not possible to define what is reasonable or unreasonable in the abstract. Each case depends upon its own circumstances. (at p49)

59. It may be added that the proprietor’s right to defend his land against water coming upon it by erecting barriers, is generally speaking restricted to penning it back on to the higher land whence it would otherwise have naturally come. It does not entitle him to divert it on to the land of a third proprietor to which it would not have naturally gone to the damage of that proprietor (at p49).

39. The defendants, in their written submissions, argued that the claim of private nuisance had been abolished by s 177(8) of the Conveyancing Act 1919 (NSW) and that the plaintiff’s claim should therefore be dismissed. The defendants put this submission on the stated assumption that the plaintiff’s claim, like the defendants cross-claim, is a “matter arising from issues relating to boundary support, or lack thereof within the definition of Section 177 of the Conveyancing Act 1919 (NSW)”.

40. The Conveyancing Act 1919 (NSW) provides, in s 177:

177 Duty of care in relation to support for land

(1) For the purposes of the common law of negligence, a duty of care exists in relation to the right of support for land.

(2) Accordingly, a person has a duty of care not to do anything on or in relation to land (the supporting land) that removes the support provided by the supporting land to any other land (the supported land).

(3) For the purposes of this section, supporting land includes the natural surface of the land, the subsoil of the land, any water beneath the land, and any part of the land that has been reclaimed.

(4) The duty of care in relation to support for land does not extend to any support that is provided by a building or structure on the supporting land except to the extent that the supporting building or structure concerned has replaced the support that the supporting land in its natural or reclaimed state formerly provided to the supported land.

(5) The duty of care in relation to support for land may be excluded or modified by express agreement between a person on whom the duty lies and a person to whom the duty is owed.

(6) Any such agreement—

(a) has effect in relation to any agent of the person on whom the duty lies, and

(b) has effect in relation to any successor in title of the supported land if the agreement is embodied in a registered easement for removal of support relating to that land.

(7) The right to agree to the removal of the support provided by supporting land to supported land is a right of the kind that is capable of being created by an easement.

(8) Any right at common law to bring an action in nuisance in respect of the removal of the support provided by supporting land to supported land is abolished by this section.

(9) Any action in negligence that is commenced after the commencement of this section in relation to the removal of the support provided by supporting land to supported land may be wholly or partly based on something that was done before the commencement of this section. However, this subsection does not operate to extend any period of limitation under the Limitation Act 1969.

(10) This section extends to land and dealings under the Real Property Act 1900.

(11) This section does not apply in relation to any proceedings that were commenced before the commencement of this section.

(12) A reference in this section to the removal of the support provided by supporting land to supported land includes a reference to any reduction of that support.

(13) This section binds the Crown in right of New South Wales and, in so far as the legislative power of the Parliament of New South Wales permits, the Crown in all its other capacities.

41. I reject the defendants’ contention that the plaintiff’s claim is a claim pursuant to s 177 of the Conveyancing Act 1919 (NSW). The plaintiff’s claim is a claim for private nuisance at common law and is not a claim in relation to the right of support for land. The defendants’ cross-claim is, however, a claim under s 177 of the Conveyancing Act 1919 (NSW).

42. The plaintiff seeks an injunction requiring the defendants to remedy the nuisance by repairing and reconfiguring the stormwater drain to conform to its original design.

Water ingress and Mr Tang’s state of knowledge

43. In his affidavit of 12 April 2024, Mr Tannous set out a detailed account of witnessing, on 20 March 2021:

… a heavy stream of water flowing into 4 … from underneath the fence on the eastern boundary, carrying with it dirt, sand and debris (the Water Intrusion). The water spread in and throughout the backyard of 4 …, covering a large portion of the backyard and flowing into the swimming pool (the Pool). The dirt and debris completely discoloured and clouded the Pool. I immediately investigated the source of the Water Intrusion, which appeared to have been flowing from 2B …. I observed significant stormwater overflow emanating from the stormwater drain on 2B….

44. I am satisfied, on the basis of the evidence of Mr Tannous, Mr Taychouri and Mr Tang, that the water ingress events related by Mr Tannous in his affidavit occurred. Those water ingress events represent a recurrent state of affairs within the meaning of that phrase in Gales Holdings.

45. Mr Tang freely admitted that he was informed of the water ingress issue by Mr Tannous in 2021. From that time on, Mr Tang knew the state of affairs, in that it must have been clear that rain events of a scale similar to the one in March 2021 would cause water to enter No 4 from No 2B in a similar way. I note that Mr Tang has a degree in engineering.

46. When the allotment which is now No 4 came into existence on the deposit of the plan of land division which divided the original allotment into two, the drainage easement was created along the western boundary, as I have said. The terms of that easement are provided in the exhibit to Mr Tannous’ affidavit (CB p 156). The Tang’s land is the dominant tenement and Mr Taychouri’s land, No 2A, is the servient tenement. The terms of the easement are:

Full and free right for every person who is at any time entitled to an estate or interest in possession in the land herein indicated as the dominant tenement or any part thereof with which the right shall be capable of enjoyment, and every person authorised by him to make layout construct erect install carry maintain and use through above on and under the servient tenement all drains pipes conduits poles wires or other equipment and electric light telephone and/or with other domestic service to and from the said dominant tenement TOGETHER WITH the right for the grantee and every person authorised by him with any tools implements or machinery necessary for the purpose to enter upon the servient tenement and to remain there for any reasonable time for the purpose of laying, inspecting cleansing, repairing, maintaining or renewing such equipment or any part thereof to such extent as may be necessary PROVIDED THAT the grantee and persons authorised by him will take all reasonable precautions to ensure as little disturbance as possible to the surface of the servient tenement and will restore without delay that surface as nearly as practicable to its original condition.

47. The easement allows for the drainage infrastructure for No 2B to be laid in the easement and maintained by the owner of No 2B. Mr Smith says, in his expert report, relying on his inspection of No 2B and the easement and the Closed Circuit Television (CCTV) assessment of the stormwater pipe carried out by Quron Pty Ltd, and in the joint report, the following with respect to the drainage infrastructure in and around the easement (in summary) (CB p 437 - 438):

48. A 150mm diameter pipe collects stormwater from the driveway and dwelling roof area of No 2B and directs it to the street. The pipe connects through Pits 1 to 4 on its way to the street. Pits 1 and 1A and Pit 2 are situated in the easement and Pits 3 and 4 are under the footpath.

49. The stormwater system was designed to have a one in ten year capacity.

50. Pit 1A is a grated strip drain across the driveway, which drains the driveway to the street along the easement.

51. The approved plan for the subdivision of No 2 into No 2A and No 2B shows a 150mm high integral kerb along the entire western edge of the driveway, for a distance of 46m. However, a topographic survey, conducted by Ross Robinson Consulting, show the kerb terminating 34.5 metres from the southern, or street, boundary. Mr Smith said that the kerb had been removed from a point at the common boundary of No 2B and No 2A to the grated inlet pit.

52. The point of the kerb was to contain any flow of stormwater runoff from the driveway which is beyond the capacity of the grated drain, Pit 1A.

53. Video recordings show water ponding around Pit 1, the grated pit, and Pit 1A, the grated strip drain. This suggests either that the pipe has insufficient capacity to deal with the water flow, or the pipe system is damaged or obstructed and unable to carry the incoming flow due to reduced capacity

54. Investigations with a small camera being fed down the stormwater pipe, where possible, show that there are objects in the pipe, the pipe is squashed and impassable in places and part of the pipe has a negative grade, so that water flows back towards No 2B rather than south towards the drainage system in the street.

55. Mr Smith, Mr Appleyard, Mr Webster and Mr Willows, in their joint report (CB p 285) said the following, in relation to the stormwater pipe in the easement (in summary):

56. The stormwater pipe was constructed in two stages. When No 2 was subdivided in 1995, a pipe was installed from the boundary between No 2A and No 2B next to the western boundary of No 2 to the street. The builder who built the dwelling on No 2B for the Tangs then extended the pipe northward to Pit 1. It was noted that Pit 1 is at a higher level that the level shown on the subdivision drainage plans drawn by Burton and Field Pty Ltd, Consulting Surveyors and suggest that Pit 1 may have been lifted when the driveway slab for the house was built. It can be inferred that the stormwater pipe was extended northward in about 1997 when the dwelling was built on No 2B.

57. The catchment area for the drainage system for No 2B is wider than the subject properties and extends to at least one or two upstream properties.

58. The gap in the kerb on the western boundary allows surface water to flow directly over the boundary from No 2B to No 4.

59. Point B is a point on the western boundary of No 2B at the northernmost corner of the awning at the front of the house. It is level with the northern side of the swimming pool on No 4. Point C is at the northernmost point of the western boundary of No 2B. Mr Smith and Mr Appleyard said that the colorbond fence posts on the western boundary of No 2B have been cored into the brick kerb between points B and C, which has compromised the integrity of the brick kerb.

60. Point A is on the south western corner of No 2B, in the easement. Between Points A and B, the concrete paving on No 2B has been cut back by circular saw to allow the construction of the colorbond fence posts to be embedded on the No 4 side.

61. A survey by Quron Pty Ltd dated 16 January 2024 shows a blockage in the stormwater pipe 500mm downstream (south) of Pit 1, towards Pit 2. The pipe is deformed (squashed).

62. For 17.26 metres from Pit 2 to Pit 1, there is a series of defects and subsidence, standing water and an impassable obstruction at 17.26 metres.

63. 58% of the stormwater pipe has not been investigated.

64. The experts agree that the land naturally falls from east to west with a secondary fall to the north.

Has No 4 suffered damage from the stormwater flow?

50. Mr Appleyard, Mr Smith and Mr Webster agreed that dirty muddy water has entered the swimming pool at No 4 from No 2B following heavy rain events and it is likely that this caused performance issues with the pool water filtration system. The swimming pool shell has cracked, which has caused problems with the tiling, among other issues.

51. Mr Smith said that there were ongoing costs for the cleaning and sanitation of the pool after stormwater overflows entered the pool.

52. Mr Appleyard noted that the paving slabs around the perimeter of the pool have settled unevenly.

53. Mr Webster said that that he thought any damage to the exterior paving related to an inappropriate subbase and he further thought that “original quality of construction was a factor”. Mr Webster had not investigated the subbase of the paving and made an assumption as to its adequacy. Mr Webster commented that the pavers around the pool would have required cleaning, but implied that the pavers should have been of an exterior grade sufficient to resist staining.

54. Mr Willows’ view, in the joint report, was that any damage was attributable to uncontrolled runoff and none of the damage was attributable to a failure of the stormwater system on No 2B. Mr Willows did not think that any of the water flows over No 4 would have caused erosion of the tiles around the pool or damage to the tiles, including cracking.

55. Mr Xue provided a report dated 17 April 2024. Mr Xue said that he inspected the marble paving around the pool on No 4 and observed it to be “unnaturally eroded on the surface”. He also observed “cracks between tiles, chips and damages to the surface of the marble and staining to the surface of the marble”. Mr Xue provided photographs which showed the damage he discussed. In all of the discussions of the outdoor paving around the swimming pool, the words “pavers” and “tiles” are used interchangeably.

56. Mr Webster, in his report, said that he thought that the flow of water and sediment from No 2B to No 4 arose from the absence of an adequate retaining wall and subsoil drainage system against the boundary. I reject this evidence because it is contrary to the evidence of Mr Appleyard and Mr Smith, whose evidence I accept. The video evidence shows that the stormwater pipe gushes up at Pit 1 and the water flows overland to No 4. As I have said, at [27], above, Mr Webster came to accept that the “great majority” of water entering No 4 from the easement and No 2B is entering overland and not by under surface seepage.

57. Mr Webster said, in his report, that he did not observe cracking “across adjacent pavers”. He did see crazing in the pavers, but said “this appears to be the characteristic of the pavers”. He was unable to comment on discolouration as he thought it was “a subjective matter”. He commented that “exterior grade pavers should be selected as fit for purpose for an exterior environment”.

58. I find that many of the marble pavers around the swimming pool on No 4 have become discoloured as a result of being deluged with muddy water from No 2B. I also accept that some of the marble pavers have cracked and chipped as a result of settling unevenly. No basis has been established upon which this damage could be attributed to the nature of the pavers or the quality or type of subbase used to lay them.

What are the causal factors of the stormwater flow from No 2B to No 4

Deformation and blocking of the stormwater pipe

59. I accept the evidence of Mr Appleyard, Mr Smith and Mr Webster that the stormwater system is almost completely blocked by the deformation and blockages in the pipe and that only a small trickle of water goes through the pipe to the public drainage infrastructure in the street during a rain event. During a sustained or heavy rain event, the pipe rapidly fills and water floods the right of way and flows over the boundary from No 2B and the right of way to the back yard of No 4 in large quantities.

60. I accept that some of the water which travelled from No 2B and the right of way to No 4 did not fall as rain on No 2B and the easement, but travelled overland to No 2B and the easement from one or more upstream properties. However, were the drainage system in the easement working as it was designed to do, much, if not all, of the water entering No 2B and the easement overland would also be captured by Pit 1A (the grating across the right of way) and travel to the street via the stormwater pipe in a rain event up to a one in ten year rain event, though I accept that the area has been built up to a larger extent than it was when the stormwater system was designed, and a larger capacity might now be appropriate on account of the increase in run-off. Certainly, a much larger amount of the water arriving overland from upstream would be drained from the site if the stormwater pipe was not blocked and deformed.

61. It was submitted in the defendants’ case that the deformation of the stormwater pipe in the easement was caused by the construction work on No 4. This was based upon an assertion made by Mr Willows in his report of 27 June 2024 that soil piping may be occurring on No 2B and No 4, which, in turn, was based upon a number of assumptions, including the assumption that the development of No 4 lowered the level of the courtyard on No 4. Mr Willows said, in his report (CB p 873):

57. The pavers settlement (eg 40 – 60 mm) and cracking in the external brick wall of No 2B are consistent with movements within the zone of influence of the No 4 pool excavation.

62. Mr Appleyard disagreed. Mr Appleyard said that the shale present 1.0m below the ground line on both No 4 and No 2 and the material above the shale is adequate to support the adjacent land (CB p 566). Mr Appleyard’s calculation of the zone of influence of the excavation for the pool and courtyard showed that it was almost on the boundary of the two properties (CB p 581). The zone of influence took in no more than 300mm of the adjacent land. The excavations on No 4 for the courtyard and pool did not undermine the soil in the easement or in No 2B.

63. In oral evidence, Mr Willows said (T p 212):

So if you have an open excavation for one, two, three weeks in a wet clay, it could become drier and it could progressively crack and cause space where those tension cracks and openings could fill with water later. So the longer you leave an excavation open for, the more likely you’re going to get erosion and slipping back into the zone of influence. What I described in this report and the mechanism that I described is not that we had a failure in 2017. It is not that the ground has slipped away under a loss of support or stability issue. The observation is that a number of years later we’ve started to see progressive settlements coming through faster and faster and an accelerating rate of damage, and that is consistent with the described – the movement of the ground underneath occurring later, consistent with it being grain by grain, carried with water in what’s caused a soil piping mechanism, or internal erosion commonly used.

Mr Willows admitted, in giving evidence, “…we don’t know about the construction process” (T p 213).

64. Mr Willows’ evidence amounts to a theory in circumstances where the factual basis for that theory has not been established on the evidence and there are other competing theories of a higher order of probability which are consistent with the known conditions on the land.

65. In cross-examination during the concurrent evidence session at the trial, Mr Appleyard said that Mr Willows’ idea about soil piping is not relevant in this matter (T p 219). I accept Mr Appleyard’s evidence. It was clear in oral evidence that Mr Willows’ fears for the stability of No 2B were based upon assumptions about what might have happened during the excavation for the swimming pool on No 4 which are not based on fact.

66. It has not been established on the balance of probabilities that the works on No 4 caused the deformation of the stormwater pipe in the easement or the blockage of the pipe.

The kerb

67. As I have discussed at [17] to [28] above, it was alleged that part of a kerb on the boundary between No 4 and No 2A and 2B was removed by builders during the construction of the improvements on No 4. There is no direct evidence that this occurred. There is no kerb between points A to B on the boundary. There is a kerb between points B and C, with the possibility that fence post construction on top of the kerb may have compromised its ability to keep water on No 2B. However, there is agreement among the engineers that the vast majority of water which has flowed across the boundary from No 2B and the easement to No 4 has flowed between points A and B; from the southwestern corner of No 2B to just north of Pit 1.

Alleged failure on No 4 to contain water from No 2B under the driveway and carport slab

68. It has not been established on the balance of probabilities that the flow of water into No 4 from No 2B is attributable to any failure of the plaintiff to comply with a requirement to build a retaining wall or by any action on the plaintiff’s behalf to remove any part of the downturn to the slab on No 4. There is no evidence that any part of the downturn has been removed.

Conclusion on the causation of the damage on No 4

69. The plaintiff did not pursue the claim that the water entering No 4 from No 2B had caused the swimming pool shell to crack. None of the experts, by the end of the trial, held the view that there was a causal connection between the water ingress and the cracks in the pool shell.

70. On the basis of the evidence of Mr Tannous, Mr Smith, Mr Appleyard, Mr Webster and Mr Xue, I find that the following damage was caused to No 4 by the overflowing of the stormwater system in the easement along the western boundary of No 2B and No 2A and the ingress of dirty water into No 4 during and after storm events:

71. repeated contamination of the water of the pool with muddy stormwater,

72. damage to the pool filtration system,

73. repeated soiling of the tiles around the pool, and

74. subsidence of the pool tiles.

75. I find that the dominant cause of the damage set out in [70], above, is the deformation and blockage of the stormwater pipe in the easement appurtenant to No 2B. The precise cause of the deformation of the pipe is unknown. The blockage is partly caused by the presence of objects and material in the pipe and is partly unknown.

76. In order to establish that the water ingress constitutes a private nuisance committed by the Tangs, the plaintiff must establish that the water ingress which caused the damage was caused by the use of No 2B. A degree of personal responsibility in the Tangs is required (see Gales Holdings at [37], above).

77. The Tangs lease No 2B to tenants for residential purposes. They do so in the knowledge that the stormwater drainage and disposal system in the easement on the western boundary of the easement has not operated sufficiently well to avoid the entry of a large amount of water into No 4 from No 2B and the easement up to eight times per year since 20 March 2021. The land division plans approved and deposited for No 2 in about 1995 provide No 2B with the benefit of the easement in the expectation that No 2B will be used for residential purposes and that the stormwater disposal infrastructure in the easement will be maintained by the owner of No 2B. The use of No 2B for residential purposes involved the building of a house and the paving of some of the land, including the right of way. This substantially reduced the capacity of the land to absorb stormwater and gave rise to the need to install a stormwater drainage system. In the context of private nuisance, the Tangs’ dereliction in the repair, maintaining and renewing of the stormwater infrastructure is an abrogation of their responsibility to No 4 to provide for adequate stormwater drainage of No 2B in a manner sufficient to avoid damage and loss to No 4.

78. I determine that the failure by the Tangs to repair, maintain and renew the stormwater drainage system in the easement constitutes a private nuisance and that the failure has caused the loss and damage set out in [70] above to Mr Tannous.

Quantum

75. Mr Xue provided a schedule of works and an estimate of costs for the rectification of the paved area around the pool (CB p 390). No other expert provided a costing for this work.

| | Description | Quantity | Unit | Rate | Subtotal | Total | | 1 | Gain access to work area in accordance with WorkCover requirements | 1 | item | note | 0 | 0 | | 2 | Site Supervision [Experience] | 2 | wks | 5,400 | 10,800 | 10,800 | | 3 | Cover and protect adjacent surfaces during the rectification work (Rawlinsons pg 269) | 8 | hr | 90.10 | 721 | 721 | | 4 | Remove pool fencing (2 men ½ day) (Rawlinsons pg 269) | 4 | hr | 90.10 | 360 | 360 | | 5 | Remove and dispose of existing marble paving (Rawlinsons p 96) | 91 | m² | 26.60 | 2,421 | 2,421 | | 6 | Disposal of marble paving (Bingo) | 3 | bins | 880.00 | | 2,640 | | 7 | Supply and install new marble paving (Rawlinsons p 132) | 91 | m² | 780.00 | | 70,980 | | 8 | Polish and seal surface (Rawlinsons pg 132) | 91 | m² | 126.00 | 11,466 | 11,466 | | 9 | Reinstate pool fencing (2 men ½ day) (Rawlinsons pg 269) | 4 | hr | 90.10 | 360 | 360 | | 10 | Make good any surfaces affected as part of the work (Experience) | 1 | item | note | 0 | 0 | | 11 | Clean site and leave in tidy condition upon completion of work (1 men 1 day) (Rawlinsons pg 269) | 8 | hr | 90.10 | 721 | 721 | | 12 | SUB-TOTAL | | | | | 100,469 |

76. Mr Xue costed the repair of the damaged pool pump and filter at $8,500 (CB p 380).

77. I have considered whether preliminaries should be added to the total cost of repairing the tiling around the pool. Mr Xue’s calculation of preliminaries and other on-costs included work to repair the swimming pool and cannot fairly be directly applied.

78. Item 3 allows 8 hours to “cover and protect adjacent surfaces during the rectification work”. This is an excessive estimate, as is the 8 hours allowed to clean the site at the end of the works. The allowance generally made for preliminaries can comfortably be covered by the excessive hours claimed in these two items.

79. Mr Xue allows for $70,980 for the supply and installation of new marble pavers over 91 square metres. The pavers are, therefore, costed at $780 per square metre. In his affidavit of 12 April 2024, Mr Tannous estimates a cost of $14,210 for the supply of marble tiles and $11,264 for the laying of the tiles plus $950 for sand and cement. Mr Tannous’ estimate is based upon a quote he obtained from Maicon Group in February 2023 which priced the pavers at $105 per square metre.

80. Mr Xue has overestimated the cost of the supply and installation of the marble pavers/tiles around the pool. The Maicon quote is nearly three years old, and prices have risen significantly in that time, but not to the extent of meeting Mr Xue’s costing. Mr Tannous, in his affidavit, commented that the damage is increasing as there are more water incursion events, and I take that into account. I will allow $40,000 for the supply of marble pavers, sand and cement, together with the installation of the pavers.

81. Given the allowance for a supervisor, there is no need to allow for a builder’s margin. I note that the Maicon quote provides for a supervisor’s allowance rather than a builder’s margin.

82. The total allowance for the replacement of the marble pavers/tiles around the swimming pool on No 4 will be $69,489, which is each item of Mr Xue’s estimate except for the supply and installation of new marble pavers, for which the cost of $40,000 has been substituted.

83. In his affidavit of 12 April 2024, Mr Tannous summarises the costs incurred in addressing the work required to clean the pool and its surrounds following each water incursion. The total is $9,393.01. This amount will be allowed.

84. I will also allow the sum of $8,500 for the replacement of the pool pump and filter in accordance with Mr Xue’s report (CB p 392).

85. Further, there will be an allowance of $12,000 in total to compensate for the diminution in amenity on No 4 since 20 March 2021. In arriving at that figure, I take into account all of the evidence of Mr Tannous and Ms Boulos.

86. The total damages in respect of the plaintiff’s claim will be $69,489 + $9,393.01 + $8,500 + $12,000 which gives a total of $99,382.01.

The further amended cross-claim

87. The Tangs pleaded, in their cross-claim:

8. At all material times the Tannous land:

8.1 provided support to the natural surface ground level of the Tang Land adjacent to and in the vicinity of the Tang Land.

8.2 was “supporting land” as described by section 177(3) of the Conveyancing Act 1919 (NSW) to the Tang Land.

8.3 provided lateral support to the subsoil of the Tang Land.

9. At all material times the Tang Land:

9.1 supported a kerb on the boundary between the Tang Land and the Tannous Land.

9.2 For 25 years, until the Tannous land was developed, suffered no issues with stormwater or subsurface water.

10. When constructing the home at 4 Nobbs Road, Yagoona, the Cross-defendant owed to the Cross-Claimants a duty of care not to do anything on or in relation to their land (the supporting land) that removes the support provided by the supporting land to any other land (the supported land).

Particulars

Section 177(2) Conveyancing Act 1919 (NSW)

11. The duty of care was not excluded or modified by express agreement between the Cross-defendant and the Cross-Claimant.

12. In breach of the duty of care, the Cross-defendant:

12.1 carried out a deep excavation along and in the vicinity of the Common Boundary.

12.2. failed to construct a retaining wall in accordance with the requirements of DA 17/2016, Drawing 15164-01 and the Development Consent for their land.

12.3 Cut and removed 16m of kerb that had been constructed by the Cross-claimants on the Common Boundary to protect the boundary and subsoil surface at the boundary.

12.4 Caused vibration on the Tang Land which weakened the subsoil or support to the subsoil on the Tang Land.

12.5 The Tang structures were within the zone of influence.

13. It was foreseeable that the Tang Land may suffer damage if appropriate and regulated measures were not taken by the Cross-defendants to support the Tang Land or not remove the support from the Tang Land.

88. Section 177 of the Conveyancing Act 1919 (NSW) is set out above at [40].

The kerb

89. As I have said, above, at [17] to [28], it has not been established on the balance of probabilities that Mr Tannous or his contractors removed any part of the kerb on the boundary between No 4 and No 2B and the easement.

90. Even if Mr Tannous or his contractor had removed part of the kerb, it would not have been relevant to the Tangs’ claim for loss of support. The kerb was on top of the ground, or on top of the concrete slab on top of the ground. The kerb did not retain soil or water present in the ground. Its purpose was to retain and redirect overland water flows on No 2B and in the right of way.

The deep excavation and the zone of influence

91. I have set out, above, my finding, based upon Mr Appleyard’s opinion, which I accept, that the zone of influence of the excavation for the pool and other improvements on No 4 did not extend into No 2B or the easement by more than 300mm. There is no evidence that any subsidence on No 2B occurred during the construction works. The finished level of No 4 is not relevantly different from the level of No 4 prior to the construction works. It is the evidence of Mr Appleyard, which I accept, that the present conditions on No 4 are not causing any damage to No 2B (see CB p 573).

The retaining wall

92. A retaining wall, constructed by Mr Tang, is in place between Points B and C on the boundary.

93. Mr Tang accepted, in cross-examination, that some subsidence was occurring on No 2B at least eight years before the redevelopment of No 4 for Mr Tannous. He also accepted that there was some cracking in his driveway prior to the building work at No 4. He thought that the level of subsidence and cracking was consistent with the age of the surfaces at the time. It was clear from his evidence, and I accept, that the subsidence and cracking have worsened over the last eight years.

94. In his amended evidence, Mr Webster says that there is no evidence at present that the residence on No 2B is subsiding. I understand that it is no longer claimed that the house has sustained damage as a result of any loss of support from No 4.

95. Mr Webster believes that the fence posts were placed into holes cut into the brick kerb between Points B and C and have had some impact on subsidence of the ground. However, he said, the brick kerb in that location has been stable against subsidence.

96. Mr Smith said, in the joint experts report, that, to the extent that there is subsidence on No 2B, it is caused by the build-up of stormwater in the blocked stormwater system along the easement flowing back onto No 2B and water overflowing from the detached garage and surface run-off flowing over No 2B. Mr Appleyard and Mr Smith did not consider that any of the cracking or subsidence of concrete or paving on No 2B is attributable to the building works on No 4.

97. Mr Willows believes that the construction works on No 4 began a process of soil piping, or subsurface erosion which undermines the structures on No 2B. Mr Willows based some of his opinion upon the belief that a kerb was in existence between Points A and B and that the kerb was removed during the building work on No 4. As I have said, this has not been established on the evidence. Mr Willows did not address the fact that the levels have not changed significantly in the course of the building work, based upon the survey plans referred to in [91] above. The competing theory, set out above at [96] is a more likely explanation for the cracking of pavement on No 2B.

98. I prefer the evidence of Mr Appleyard and Mr Smith to that of Mr Willows and Mr Webster on the cross-claim. The evidence of Mr Willows and Mr Webster did not draw a clear causal connection between the works on No 4, or the absence of a retaining wall on No 4, and impacts on No 2B. Their evidence relied on assumptions and assertions which have not been substantiated on the evidence.

99. Both Mr Willows and Mr Webster interpreted the Development Approval for the dwelling on No 4 as imposing a requirement for a retaining wall to be built by Mr Tannous. This interpretation of the Development Approval is contestable. In any event, in this matter, to succeed in that part of their claim which concerns the absence of a retaining wall, the cross-claimants need to prove that the absence of a retaining wall on the boundary between the properties has caused damage to No 2B. This causation has not been established on the evidence, on the balance of probabilities.

Vibrations

100. There is no evidence before me in support of the allegation in the cross-claim that damage has been caused to No 2B arising from vibrations on No 4.

Conclusion on the cross-claim

101. Mr Tannous has a duty under s 177(2) of the Conveyancing Act 1919 (NSW) not to do anything on No 4 that removes the support provided by the land on No 4 to No 2B or the easement.

102. It has not been established by the Tangs, on the balance of probabilities, that anything done in the course of the ownership of No 4 by Mr Tannous, including the building works and the excavation for the swimming pool, removed the support provided by No 4 to No 2B.

103. It has not been established that Mr Tannous has breached his duty of care to the cross-claimants under s 177 of the Conveyancing Act 1919 (NSW).

Summary and conclusion

104. The plaintiff has succeeded on the claim. The defendants have wrongfully interfered with the enjoyment of the plaintiff’s enjoyment of No 4 by permitting recurrent incursions of water from No 2B into No 4, causing damage to the paving around the swimming pool and the pool equipment, as well as a loss of amenity. The recurrent incursions of water into the plaintiff’s land are a consequence of the defendants’ failure to maintain the stormwater disposal system in the easement appurtenant to the defendants’ land.

105. The defendants have not succeeded on their cross-claim. On the evidence, it has not been proven on the balance of probabilities that the cross-claimants’ land has suffered a loss of support from the plaintiff’s land within the meaning of s 177 of the Conveyancing Act 1919 (NSW).

106. The following orders will issue:

107. Judgment and verdict for the plaintiff on the plaintiff’s claim.

108. The defendants shall forthwith remedy the nuisance caused by stormwater escaping from the defendants’ land at 2B Nobbs Road, Yagoona, New South Wales (the land) and the drainage easement over 2 Nobbs Road, Yagoona, New South Wales (the easement) by the defendants repairing and reconfiguring the stormwater drainage system on the land and the easement so that it is in accordance with the drainage plan being Reference Number 51056/95-29814 dated 16 March 1995 approved and stamped by Bankstown Council in relation to Development Application 2002/95.

109. The defendants shall pay to the plaintiff damages in the sum of $99,382.01.

110. Judgment for the plaintiff on the defendants’ cross-claim, and the defendants’ cross-claim is dismissed.

111. I will hear the parties as to costs.

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