Civil and Administrative Tribunal New South Wales Medium Neutral Citation: O'Rourke v Beechwood Homes (NSW) Pty Ltd [2022] NSWCATCD 116 Hearing dates: 8 April 2022 Date of orders: 07 July 2022 Decision date: 07 July 2022 Jurisdiction: Consumer and Commercial Division Before: D Robertson, Senior Member Decision: 1. Within four months of the date of publication of this decision, the respondent, Beechwood Homes (NSW) Pty Ltd, is to carry out the following works at xx Glenbrook Road, Glenbrook, in a proper and workmanlike manner: (1) Reconstruct the absorption trench from the base up, in accordance with the plans provided by Quantum Engineers, to restore its hydraulic capacity to infiltrate stormwater. This includes the gravel bed on which the trench is laid. The arches can be reused if practicable, the geofabric needs to be replaced and backfill material may be reused provided that it contains only coarse filter sand free of silts and fine particles as specified in the approved stamped design drawings. The reconstruction must include the geofabric blanket with 4 removable half brick keepers per pit and maximesh placed across the entry to the arches; (2) Reinstate the capacity of the weep holes of the stormwater pit by cleaning them out with an appropriate tool (such as a hand auger) to restore their capacity and replace any lost gravel below. If this should prove impractical the pit will need to be reconstructed to restore the weep hole capacity; (3) Provide a flood bund along the southern property boundary from the edge of the neighbouring house to the road reserve boundary; (4) Construct a defined overland flow path in the rear of the yard with sufficient capacity to convey peak 1 in 100 year storm flows from the upstream catchment to ensure this is directed away from the house and around the stormwater pit to prevent the stormwater pit from being deluged by overland flows; (5) Refine the temporary overflow strip drain so that overflows from the stormwater pit are dispersed across a wide area so they do not result in water ponding against the fence; and (6) Construct a grated drain across the driveway at the front of the house to further disperse overland flows of stormwater before they can enter the garage. 2. Pursuant to Schedule 4 Clause 8 of the Civil and Administrative Tribunal Act, 2013 (NSW) the applicant has leave to renew the proceedings if these orders are not complied with by the respondent. Catchwords: BUILDING AND CONSTRUCTION – Home Building Act 1989 (NSW) – Statutory warranties – Warranty that works will be carried out with due care and skill – Whether approval of plans by Council absolves builder from responsibility to ensure adequate provision is made for the dispersal of stormwater Legislation Cited: Civil and Administrative Tribunal Act 2013 (NSW) Civil and Administrative Tribunal Rules 2014 (NSW) Home Building Act 1989 (NSW) Cases Cited: Bellgrove v Eldridge (1954) 90 CLR 613 Texts Cited: Nil Category: Principal judgment Parties: Kevin O'Rourke (Applicant) Beechwood Homes (NSW) Pty Ltd (Respondent) Representation: Nil File Number(s): HB 21/30597 Publication restriction: Nil REASONS FOR DECISION 1. The applicant owns a property in Glenbrook. On 23 May 2018 the applicant and the respondent executed a contract for the design and construction of a dwelling on the applicant's property. The contract specifically required the respondent to undertake the following work: "5. Stormwater drainage to water tank via a charge line within 10 metres of connection point (including round PVC downpipes and overflow to pits). Note: 2 x 6m pits allowed. 6. Provide hydraulic storm water details from Quantum Engineers. 7. Amended Hydraulic Stormwater Details due to OSD requirements. 8. Provide storm water drainage in accordance with hydraulic storm water detail. * NOTE: Grated drain By Owner after settlement." 1. The respondent obtained plans from Quantum Engineers for the construction of the stormwater drainage. 2. The applicant's block has a street frontage to the west and slopes generally to the east. The stormwater system was designed to run from west to east along both sides of the house. On the north side the plans provided for two on-site detention/rainwater tanks, each of 4000 litres. The overflow from the tanks and stormwater from the southern side of the house was to be directed through 100 mm pipes to two 6 metre absorption trenches in the rear yard, that is to the east of the house. 3. On the south side, the drain was designed to run from the front (west) side of the house, across the front of the house under the driveway, and along the south side of the house to the rear of the house and then to the absorption pits. 4. The applicant alleges that the system was constructed in breach of the statutory warranties implied into the contract by section 18B of the Home Building Act 1989 (NSW) (HBA). 5. The applicant alleges that the stormwater system is not adequately designed to accommodate overland flow, as a result of which the applicant's garage has been flooded. The applicant claims that the carpet in an adjacent bedroom was ruined and required replacement. 6. The applicant further alleges that the absorption trench is silted and inoperative. 7. The applicant thirdly alleges that the depth of the absorption pit is insufficient. 8. The applicant seeks an order that the respondent do work to rectify the stormwater system or alternatively compensation for breach of the statutory warranties in an amount identified in the original application as $29,999 and in the points of claim as $21,000 to $26,000. 9. The respondent filed points of defence which asserted: "7. In the alternative, in the event that the System did not comply (which is denied), the Respondent says that the Applicant compromised the operation of the System by placing pavers over it (or alternatively, partly over it), affecting its intended use and operation. The Respondent further says that the Applicant's actions broke any relevant chain of causation. 8. To the extent that the Applicant alleges that the designer of the storm water system was required to take into account matters such as: (a) overland flow; and (b) major flooding events, this is denied. 9. By way of elaboration upon the paragraph above, the Respondent says that the design of the System was appropriate and had regard to the required relevant matters, being: (a) relevant Local Environment Plan; (b) relevant Development Control Plan; and (c) Australian Standard AS3500.3. Particulars This is evidenced by Blue Mountains City Council, as the relevant consent authority granting development approval for the building works and the System at the Property and issuing an occupation certificate in relation to the building works." The Evidence 1. The applicant filed a bundle of documents including points of claim, a chronology and a report prepared by Mr Mark Liebman of Sustainability Workshop Ltd. Mr Liebman is a chartered professional engineer with degrees in economics and civil and environmental engineering. Mr Liebman has over 20 years professional civil engineering experience with a specialist focus on stormwater, flooding, drainage and water quality. Mr Liebman's report acknowledged the Expert Witness Code of Conduct and stated that the report had been prepared in accordance with the Code of Conduct. 2. The respondent had filed evidence in earlier proceedings between the parties. That evidence consisted of a bundle of documents containing 21 pages. The respondent relied upon that evidence in these proceedings. The respondent's bundle included a statement prepared by Mr Robert Eltobbagi of Quantum Engineers, the hydraulic engineers who designed the stormwater system. The plans disclose that Mr Eltobbagi was the engineer from Quantum Engineers who had approved the drawings. Mr Eltobbagi's statement did not refer to the Expert Witness Code of Conduct. 3. Mr Eltobbagi's evidence was that Quantum Engineers were engaged only to prepare conceptual stormwater plans for the proposed dwelling. He stated that Quantum Engineers was not engaged to prepare "construction certificated" stormwater plans. He stated that Quantum Engineers did not undertake any inspections during construction and were not engaged to inspect and issue "Work as Executed" certification. 4. Mr Eltobbagi asserted: "6. Blue Mountains City Council (BMCC) by issuing Construction Certificate for the New Dwelling, deemed the DA Conceptual Stormwater Plans fit for construction. As the Certifying Authority, BMCC were accountable and responsible for the failure in requesting 'Construction Certified' Stormwater Plans". 1. Each of Mr O'Rourke, Mr Liebman, and Mr Eltobbagi gave evidence on oath or affirmation. Mr O'Rourke verified the chronology in his bundle of documents, which was treated as his evidence in chief. Mr O'Rourke and Mr Liebman were cross-examined by Mr Wilson, the solicitor who appeared for the respondent. Mr Eltobbagi was asked questions by the Tribunal and by Mr O'Rourke. 2. The applicant's bundle included evidence of the flooding of the garage and side pathway in February and March 2020 during what Mr Liebman identified as a rain event "of return period greater than 30 years". 3. Mr Liebman's report stated: "11 l observed the position of the house in the topography noting that it is a low lying dwelling adjacent to an old Paperbark swamp, i.e. is close to swampy ground. … 12 The site is located across the road from Glenbrook Lagoon which is a perched lagoon with permanent water level controlled by a piped overflow. There was no overflow from the lagoon occurring at the time of either site investigation. It was dry weather during both investigations. 13 It would be reasonable to assume that local groundwater levels would be dictated in part by the water level in the lagoon. 14 It was anecdotally observed that the ground level on the eastern side of the lagoon, at [the applicant's property] is about 300-400mm above the pipe invert meaning that it is likely that groundwater would be fairly close to the ground surface at [the applicant's property]. … 17 I observed an infiltration system comprising of a concrete stormwater pit with weep holes in its base connected to two parallel plastic arches which, according to the design plans extend for a distance of 6m. 18 I observed a large amount of silty material deposited into the arch systems. They appeared to be 50% full of silty sediment and gravel. 19 The stormwater pit leading to the infiltration system was observed to have water up to a depth of 405mm from the base of the pit. The arched system is 400mm high and is located 200mm above the base of the pit. This means the arches had approximately 200mm of water in them and were 50% full. Needless to say their capacity was substantially diminished. 20 There was no rainfall on the 4th May or on the preceding 2 days. 21 At my request the Proprietor emptied the trench with a bucket to establish if it would "recover", i.e. to determine if the trench system was holding water within, i.e. if it was clogged or if it was groundwater seepage present in the system. If groundwater, then after emptying it would recover within a day or two at most. 22 During the second site investigation a week later I observed the stormwater pit had recovered to a depth of 185mm but there was no ponding of water within the arches. 23 From these observations we are able to conclude that it is likely that groundwater is close to the base of the infiltration system-recovery inside the stormwater pit which has weep holes and which is connected to the groundwater would indicate this as would the presence of water in the temporary hole dug 1m away from the trench. 24 We are able to conclude that the trench is holding water rather than subject to groundwater inundation - we can conclude this because the trench itself did not recover once drained. 25 The observed sandy, silt and gravel deposited in the base of the trench is potentially a reason the trench is holding water. Either because the material is directly clogging the trench or because the silty material has clogged the geofabric which surrounds the trench clogging its pores and reducing its conveyance capacity. 26 When on site I did not observe any measures undertaken to prevent, control or direct overland flows which would enter the property from the south." 1. Mr Liebman's report stated that the Quantum Engineers plans were of a good standard and generally complied with the Blue Mountains City Council Development Control Plan 2005 (DCP 2005). Mr Liebman stated that: "64 The drawings show that habitable floor levels are to be 300mm above proposed finished levels - it shows cut and fill levels of the building pad at RL 202.27 m while the habitable floor level is at RL 202.57 m which is 300mm above. 65 The design however neglects to consider that this site is subject to overland flows where flows from upstream properties would flow onto xx Glenbrook Road in major storm events such as the one which occurred during February 2020. 66 Quantum Engineers, by either inspecting the site and locality or by analysing a topographical map, freely available on-line, should have identified the risk or potential for overland flows to enter the property and as a result floor levels should have been raised more than 300mm above the finished ground level. This could have been achieved by raising the floor level and in part by shaping and lowering the rear yard level to push flows away from the house and side passage of the house. … 67 There is significant concern that while the house was not inundated in the February 2020 event (reportedly it was very nearly inundated) which was something approximating a 1 in 30 year flood event that it would therefore be inundated during a 1% AEP flood event (1 in 100 year event). This would result in considerable damage to property." 1. Mr Liebman referred to clause 5.4.2 of Australian Standard AS 3500 "Overland Flood Path". 2. Mr Liebman stated: "72 Clause 5.4.2 creates a responsibility for designers to set floor levels and shape overland flow paths to avoid the consequences of failure and to prevent entry of water into buildings. 73 This repeats the responsibility of DCP 2005 and requires that designs consider major overland flow paths." 1. Mr Liebman noted that drainage systems are required to be designed for a minor system, that is the pits and pipes which are designed for a one in two year recurrence interval, and a major system, to cater for flows up to the one in 100 year storm event. He stated: "75 The design by Quantum Engineers neglected to consider major overland flows which is the more significant part of the drainage system. It did however provide significant attention to the minor flows. 76 Moreover clause 5.4.2 in AS3500.3 provides a remedy where this does not occur- refer to points a) to c) in the clause. In this case it would be appropriate to alter surface levels and flow paths by regrading and redirection in the rear yard and provision of bunds in the front yard to direct flows around the front. It is clearly too late to raise the floor level. 77 The residual risk of any remedial solution for this site needs to be carefully considered by all parties. By this we mean that it may now not be possible to ensure this dwelling is not inundated in a 1 in 100 year storm event. … 1. Mr Liebman concluded: 87 That part of the stormwater system design which is called the major system, i.e. that part of the system which is required to manage overland flows is not fit for purpose and does not comply with AS3500.3, DCP 2005 or Australian Rainfall and Runoff. 88 The designer may argue he was not engaged to check overland flows and to design a major stormwater system compliant with DCP 2005, ARR and AS3500.3 however the design drawings clearly show intent to comply with DCP 2005 and its reasonable for the Proprietor to expect that the stormwater drainage system, designed by a Chartered Professional Engineer, comprised of both a minor and major system, complied with all relevant Australian Standards and Development Control Plans and industry accepted practice, i.e. Australian Rainfall and Runoff. 1. Mr Liebman suggested remedial solutions, noting that, as it is not possible to raise the floor level of the applicant's house, it may not be possible to prevent the dwelling from being flooded in a one in 100 year storm event, but that there were specific measures which might be taken to mitigate the risk. Specific measures identified by Mr Liebman included: "a. Providing a flood bund along the southern property boundary from the edge of the neighbouring house at xx Glenbrook Road to the road reserve boundary. This should direct any overland flows down to the footpath and around the property. This is intended to reduce the flood risk to the front of the house and the garage. This is not likely to be a costly measure. b. To construct a defined overland flow path in the rear of the yard to ensure this is directed away from the house and around the stormwater pit to prevent the stormwater pit from being deluged by overland flows. The overland flow path should have sufficient capacity to convey peak 1 in 100 year storm flows from the upstream catchment. It must consider that roof systems will fail in large events and include relevant areas of roof and impervious areas of upstream property within the catchment. This is not likely to be a costly measure. c. Refine the temporary overflow strip drain, which is essentially a level spreader, so that overflows from the stormwater pit are dispersed across wide area so they do not result in water ponding against the fence. This is not likely to be a costly measure. " and the construction of a grated drain across the driveway at the front of the house to further disperse overland flows of stormwater before they could enter the garage. 1. As noted, Mr Liebman stated, in relation to the design of the infiltration system, that the sizing of the trench complied with the relevant development control plan. Mr Liebman recorded that: "79 The proximity of the base of the trench to groundwater does not appear to have been considered by the designer. There is no evidence of any kind of geotechnical investigation undertaken by Beechwood or the designer. Had a basic desktop investigation be undertaken it would have revealed that groundwater levels would be likely to be elevated in that location because of: a. The proximity to the lagoon across the road which would undoubtedly influence groundwater levels. b. The location of the site in that landscape - apart from the lagoon the site is sitting nearly at the bottom of the hill where there is a localised depression which was identified as an old Paperbark swamp. … 81 We conclude that the presence of groundwater close to the base of the trench should not result in the trench failing to empty more than 3 days after a rain event. In this context, the design of the infiltration system is considered adequate. 82 The design did include a 200mm deep silt trap to remove silt/sediment or prevent sediment from entering the arches in the stormwater pit. This is good practice and should have prevented operational phase sediment loads from entering the arches. 83 The design did include a sediment and erosion control plan which clearly showed that the stormwater pit should have had a sediment fence placed around it during construction. This would have prevented construction phase sediment from entering and clogging the system. 84 We make the following concluding remarks. The infiltration system is considered part of the minor stormwater system. The size of the trench complied with the DCP and this is not in question. 85 The presence of groundwater below the bottom of the arch system should not affect its ability to drain the arch system dry but it does affect the ability of the sump in the pit to remain dry. 86 We conclude that that part of the design, which is called the minor system, i.e. the pits, pipes, roof drainage, rainwater tank and infiltration system is fit for purpose and the design and documentation was clear and fit for purpose." 1. Mr Liebman noted that two minor elements were missing from the construction of the infiltration system, being "a geofabric blanket with 4 removable half brick keepers per pit", to prevent the weep holes from clogging and maximesh placed across the entry to the arches to prevent "gravel and gross pollutants" from entering the pit. 2. Mr Liebman stated that: "91. The presence of a huge sediment slug within the system however could only have been directed into the trench during construction. This is either the responsibility of Beechwood as the site manager or the Plumbing Contractor." 1. Mr Liebman referred to the Council's inspection notes made during construction, which noted that more sediment control was required, and stated: "94. The evidence from the site investigation together with this evidence suggests that the infiltration system has become fouled with a sediment slug during construction and this has caused the base of the system to a depth of 200mm to become clogged. ... 96 It is not possible for me to establish how the sediment was deposited in the pit but from the evidence above it is clear that a lack of sediment and erosion controls on site during the construction phase has caused this infiltration system to lose its capacity, become filled with significant volumes of sediment and gravel and to become clogged." 1. Mr Liebman stated: "103. The trench needs to reconstructed from the base up to restore its hydraulic capacity to infiltrate stormwater. This includes the gravel bed on which it is laid which has become clogged with fine particles. The arches can probably be reused, the geofabric needs to be replaced and backfill material might be fit for reuse provided that it contains only coarse filter sand free of silts and fine particles as specified in the approved stamped design drawings. … 107. The weep holes of the stormwater pit will also need their capacity reinstated. This may be achieved by cleaning them out with an appropriate tool (hand auger??) to restore their capacity and replacing any lost gravel below. Alternately reconstruct the pit to restore the weep hole capacity." 1. The applicant sought orders requiring the respondent to undertake the work described by Mr Liebman and, in the alternative, compensation. 2. The applicant obtained quotations: 1. From Rapid Plumbing Group for the replacement of the existing 6 m absorption trench with a 12 m trench and the cutting in of a strip drain across the driveway at a cost of $12,456. 2. From Upper Mountains Plumbing and Gas for "a permanent stormwater relief system, consisting of a stormwater catchment drain across driveway in front yard and a 450 mm pit for catchment in backyard", at a cost of $5150. 1. The applicant also provided a quote from Carpet Call Floor Centre for the removal of existing flooring and supplying and laying carpet in "one guest bedroom" at a price of $1250. 2. Mr Eltobbagi's evidence was that "thick concrete pavers had been placed completely over the infiltration's 'surcharge' grate lid in an effort to 'stop' surcharge flows from escaping from the infiltration trench" and that "the concrete pavers compromise the system which led to the surcharging at the next possible surcharge point – which, based on the WAE [works as executed] survey, is the garage grated drain and the surface grates along the southern boundary setback". 3. Mr Eltobbagi stated that: "9. Blue Mountains City Council and Quantum Engineers consider that the site IS NOT AFFECTED by major overland flow. BMCC Engineers reviewed the 'DA' Conceptual Stormwater Plans during the DA Assessment process and deemed major overland flow is not applicable to the site." 1. Mr Wilson's cross-examination of Mr Liebman sought to establish three propositions. 2. The first proposition was that Mr Liebman had not reviewed the certificate issued by the Blue Mountains City Council pursuant to section 10.7 of the Environmental Planning and Assessment Act, which stated: "(1) Whether or not development on that land or part of the land for the purposes of dwelling houses, dual occupancies, multi dwelling housing or residential flat buildings (not including development for the purposes of group homes or seniors housing) is subject to flood related development controls. The Council does not know. (2) Whether or not development on that land or part of the land for any other purpose is subject to flood related development controls. The Council does not know." 1. Each of those statements bore the note: "Note: A Flood Risk Management Study and Plan has not been prepared for the catchment in which the land is located. The Council does not know the location and identity of land within the catchment that may be wholly or partly below the Council's Flood Planning Level (FPL), being the level of the 1:100 year flood plus 500mm freeboard." 1. Mr Liebman agreed that he had not reviewed the s 10.7 certificate. Mr Wilson suggested to Mr Liebman that the certificate disclosed that Council was not of the view that the land was subject to overland flow. Mr Liebman responded: "No – Council does not have a view" 2. The second proposition which Mr Wilson sought to establish was that Mr Liebman in preparing his report had not had regard to the development consent conditions imposed by Council. Mr Liebman agreed with that proposition. Mr Wilson put to Mr Liebman that the council approval specified that the floor of the dwelling should be 250 mm above the surrounding ground level. Mr Wilson suggested to Mr Liebman that the imposition of that condition indicated that the council must have concluded that the site was not affected by the overland flow of stormwater. 3. Mr Liebman's evidence was that he did not believe the Council has a view either way. Mr Liebman did agree that, if Council had thought that the land was affected by stormwater, it would have required a 300 mm clearance. 4. I note at this point that the fact that the Council did not have a positive view that the property was affected by stormwater does not mean that the property was not affected by stormwater 5. Mr Liebman maintained that good engineering practice required the flood risks to be assessed holistically. Mr Liebman pointed out that the property is on low-lying land across the road from a confined lagoon with the road between the property and the lagoon effectively forming a dam wall. 6. The third proposition which Mr Wilson sought to establish was that the pavers placed over the grate were responsible for the flooding which to the applicant's garage which had occurred in February 2020. Mr Liebman disagreed. He noted that the pavers were apparently only loosely placed over the grate and stated: "I do not believe they could have held back the stormwater." 7. Mr Liebman agreed that infiltration pits are designed to surcharge when at capacity, which is why they are covered by a grate rather than a manhole. However, whether a manhole or the pavers would have prevented the system surcharging depends upon the pressure within the system. Mr Liebman stated that he had seen very heavy covers removed by water pressure and that, if a surcharge was strong enough it might knock any cover off. 8. Mr Liebman agreed that, if the infiltration pit was covered and not able to surcharge as designed, the system would then discharge at the next surcharge point up the line. Mr Liebman acknowledged that the surcharge points up the line from the infiltration pit were at the front of the garage, although there were small inlet pits in the side passage on the southern boundary. 9. The applicant's evidence regarding the pavers was that he had placed them over the grate of the pit to enable him to get his lawnmower over the pit in order to mow the lawn. The applicant gave evidence that he had removed the pavers after the February 2020 flood and had still been flooded in 2021 and 2022. The applicant acknowledged that he had not included any reference to floods in 2021 and 2022 in his evidence bundle. 10. During Mr Eltobbagi's oral evidence, the applicant asked him whether it was difficult to remove the pavers. Mr Eltobaggi agreed that it was not difficult to remove the pavers, but asserted that they would "definitely impact the system" and that "the point of the grated pits is to surcharge, anything restricting a pit from surcharging will impact the system". 11. Mr Wilson submitted that I should not accept Mr Liebman's evidence and that I should not accept that the property is subject to overland flows. In putting that submission Mr Wilson relied upon two charts or maps (identified as F-20 and F-21) which showed, respectively, ground contours and "preliminary 1% AEP (100 YR ARI) flood map". The latter document did not show the inundation of the applicant's property but it is noted on the map that "flood depth less than 100 mm has been filtered out in this flood map". Consideration 1. I accept Mr Liebman's evidence. I consider him appropriately qualified and objective. He had acknowledged the Expert Witness Code of Conduct. He did not resile from his evidence under cross examination. I accept that the property is subject to overland flows. The flood map at F – 21 does not establish that water will not flow across the property in a storm event and does not establish that the property will not be inundated to a depth of up to 100 mm in a 1% AEP [annual exceedance probability] event. 2. I accept that the pavers would have had some impact in causing flooding near the garage but am not persuaded that they are sufficient explanation for the degree of flooding. I accept Mr Liebman's evidence that the provision made by the respondent for overland flow is insufficient. I do not consider that Mr Eltobbagi's evidence, which sought to blame the pavers for the entirety of the flooding, was independent or persuasive. To the extent that the evidence of Mr Liebmand and Mr Eltobbagi was in conflict, I prefer Mr Liebman's evidence. 3. I do not consider that the respondent can avoid responsibility for the insufficiency of the major stormwater system by reference to the Council's approval of the stormwater management plan. The contract required the respondent to provide hydraulic stormwater details and stormwater drainage in accordance with the hydraulic stormwater detail. I note that Mr Eltobbagi was reluctant to take responsibility for his own design, suggesting the plans provided were "DA conceptual" plans and that Quantum Engineers was not engaged to prepare "construction certificated" plans. 4. There was no evidence presented by the respondent to contradict Mr Liebman's evidence that the absorption pit requires reconstruction as it is affected by siltation. The respondent made some attempt to suggest that the siltation might be a consequence of landscaping work undertaken by the applicant. However there was no cross examination of the applicant to establish the extent of the works for which he was responsible. 5. Mr Liebman's opinion was that the siltation was likely to have been the consequence of a failure to protect the absorption pit during construction. I accept that evidence. 6. Although Mr Liebman did comment about the depth of the pit in relation to the groundwater he did not suggest the pit required reconstruction on that ground. 7. I am satisfied that the stormwater provision constructed by the respondent on the applicant's property breached the statutory warranty in section 18B(1)(a) of the HBA, that is that work will be carried out with due care and skill. It was the respondent's responsibility to ensure appropriate stormwater provision was made and the respondent has failed to carry out that responsibility. 8. It was also the respondent's responsibility to ensure that the absorption pit would be fit for purpose and not silted up. On the basis of Mr Liebman's evidence, I consider that the applicant has established on the balance of probabilities that the "sediment slug" in the absorption pit was caused by a failure on the part of the respondent to provide adequate protection against sediment flows during construction. Remedies 1. Section 48MA of the HBA provides: 48MA Rectification of defective work is preferred outcome in proceedings A court or tribunal determining a building claim involving an allegation of defective residential building work or specialist work by a party to the proceedings (the responsible party) is to have regard to the principle that rectification of the defective work by the responsible party is the preferred outcome. 1. The applicant does not suggest that a work order would be inappropriate. I consider that the respondent should be directed to carry out the work outlined by Mr Liebman. 2. In relation to the "minor system", that work is: 1. Reconstruct the absorption trench from the base up, in accordance with the plans provided by Quantum Engineers, to restore its hydraulic capacity to infiltrate stormwater. This includes the gravel bed on which the trench is laid. The arches can be reused if practicable, the geofabric needs to be replaced and backfill material may be reused provided that it contains only coarse filter sand free of silts and fine particles as specified in the approved stamped design drawings. The reconstruction must include the geofabric blanket with 4 removable half brick keepers per pit and maximesh placed across the entry to the arches; and 2. Reinstate the capacity of the weep holes of the stormwater pit by cleaning them out with an appropriate tool (such as a hand auger) to restore their capacity and replacing any lost gravel below. If this should prove impractical the pit will need to be reconstructed to restore the weep hole capacity. 1. Although, as Mr Liebman stated, the rectification necessary to ensure the house is not subject to stormwater penetration might be to raise the floor level, that is not a reasonable course to adopt (as Mr Liebman stated at 76 (see [21] above), "it is clearly too late to raise the floor level"), and it is thus not an appropriate remedy: Bellgrove v Eldridge (1954) 90 CLR 613. For that reason, I consider that the appropriate remedy in relation to the "major system", to place the applicant as far as possible in the position he would have been in if the respondent had fulfilled its contractual obligations in relation to the overland flow of stormwater, is to undertake the mitigating solutions proposed by Mr Liebman, that is: (3) Provide a flood bund along the southern property boundary from the edge of the neighbouring house to the road reserve boundary; (4) Construct a defined overland flow path in the rear of the yard with sufficient capacity to convey peak 1 in 100 year storm flows from the upstream catchment to ensure this is directed away from the house and around the stormwater pit to prevent the stormwater pit from being deluged by overland flows; (5) Refine the temporary overflow strip drain so that overflows from the stormwater pit are dispersed across a wide area so they do not result in water ponding against the fence; and (6) Construct a grated drain across the driveway at the front of the house to further disperse overland flows of stormwater before they can enter the garage. 1. It is appropriate that the respondent be allowed a reasonable period to carry out the works which I will order it to undertake. I consider four months would be appropriate. It is appropriate to grant the applicant leave to renew the proceedings in the event that the work orders are not carried out. 2. The applicant also seeks the cost of replacement of the carpet in the guest bedroom, in respect of which he obtained the quote from Carpet Call Floor Centre for the amount of $1250. However, I do not consider that the evidence tendered by the applicant provides any basis to conclude that the guest bedroom carpet has been damaged by reason of flooding arising from the inadequate stormwater provision constructed by the respondent. 3. The amount sought by the applicant in his points of claim also included the cost of a development application to Blue Mountains City Council and the cost of Mr Liebman's report. As I have made a work order, it will be for the respondent to obtain any necessary development consent for the remedial works. The cost of Mr Liebman's report is part of the costs of the proceedings. The amount in dispute in the proceedings (including the cost of the rectification work sought by the applicant) does not exceed $30,000. Accordingly, rule 38 of the Civil and Administrative Tribunal Rules 2014 (NSW) does not apply and, pursuant to the provisions of section 60 of the Civil and Administrative Tribunal Act 2013 (NSW), special circumstances would be necessary to justify an order that the respondent pay the applicant's costs of the proceedings. I am not persuaded that there are special circumstances in this case. 4. The applicant's points of claim also seek $4000 in respect of the cost of obtaining an easement over the neighbouring property "if the drainage cannot be resolved". This claim is entirely speculative, and I do not consider that the applicant has established an entitlement to payment of that amount. 5. Had it been appropriate to award damages rather than making a work order, I would have assessed the cost of rectification by reference to the quotations obtained by the applicant from Rapid Plumbing Group and Upper Mountains Plumbing and Gas, that is $17,606. 6. My orders are: 1. Within four months of the date of publication of this decision, the respondent, Beechwood Homes (NSW) Pty Ltd, is to carry out the following works at xx Glenbrook Road, Glenbrook, in a proper and workmanlike manner: 1 Reconstruct the absorption trench from the base up, in accordance with the plans provided by Quantum Engineers, to restore its hydraulic capacity to infiltrate stormwater. This includes the gravel bed on which the trench is laid. The arches can be reused if practicable, the geofabric needs to be replaced and backfill material may be reused provided that it contains only coarse filter sand free of silts and fine particles as specified in the approved stamped design drawings. The reconstruction must include the geofabric blanket with 4 removable half brick keepers per pit and maximesh placed across the entry to the arches; 2 Reinstate the capacity of the weep holes of the stormwater pit by cleaning them out with an appropriate tool (such as a hand auger) to restore their capacity and replace any lost gravel below. If this should prove impractical the pit will need to be reconstructed to restore the weep hole capacity; 3 Provide a flood bund along the southern property boundary from the edge of the neighbouring house to the road reserve boundary; 4 Construct a defined overland flow path in the rear of the yard with sufficient capacity to convey peak 1 in 100 year storm flows from the upstream catchment to ensure this is directed away from the house and around the stormwater pit to prevent the stormwater pit from being deluged by overland flows; 5 Refine the temporary overflow strip drain so that overflows from the stormwater pit are dispersed across a wide area so they do not result in water ponding against the fence; and 6 Construct a grated drain across the driveway at the front of the house to further disperse overland flows of stormwater before they can enter the garage. 1. Pursuant to Schedule 4 Clause 8 of the Civil and Administrative Tribunal Act, 2013 (NSW) the applicant has leave to renew the proceedings if these orders are not complied with by the respondent. ********** I hereby certify that this is a true and accurate record of the reasons for decision of the Civil and Administrative Tribunal of New South Wales. Registrar DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 30 August 2022