33 From as early as 1960 the Northumberland Planning Scheme zoned the ephemeral wetland 6(a) Recreation and the balance of the subject land 2(a) Residential. Planning schemes in their application to the subject land were amended from time to time. In 1974 the subject land was zoned in part 2(d) Residential, in part 2(c)(i) Residential and the ephemeral wetland was zoned 6(a) Recreation. In 1981 and after the introduction of the Environmental Planning and Assessment Act 1979 the Northumberland Local Environmental Environment Plan No 1 zoned the land as it had been previously zoned and this zoning was repeated in the Port Stephens LEP No 83 made in November 1985. In November 1987 the Port Stephens LEP was amended and the ephemeral wetland was zoned Public Recreation and the balance of the subject land 2(a) Residential. In June 1998 the whole of the subject land was zoned 2(b) Residential. In 2000 Port Stephens LEP was further amended and the land was zoned 2(a) Residential -the difference between the 1998 and 2000 zonings was that under the latter zoning smaller lots could be used for building than under the former.
34 As I have mentioned the Council undertook extensive drainage works in the 70's. During the 70's, 80's and 90's Mrs Coventry lived in Sydney. She visited the subject land at irregular intervals. In 1972 she planned to sub-divide the subject land and although the project did not proceed her submission to Council made it clear that she wished the ephemeral wetland to be preserved as a "lake". In a rough sketch plan attached to her subdivision proposal she indicated the location of roads and residential development which would be above the "flooding level" of the ephemeral wetland.
35 In about the middle of the 70's Mrs Coventry became aware that a noxious plant was growing on the subject land the seeds of which, apparently, were brought onto it by surface water. She noticed for the first time that there were stormwater pipes draining onto her land. She took the matter up with Council who told her it was not prepared to remove the artificial drainage which it had constructed to service the Seabreeze Estate and associated roads and gutters although it would be willing to limit the amount of water coming onto the land by installing a pumping station (which it never did).
36 In her dealings with the Council Mrs Coventry was anxious that the Council recognise the importance she attached to the pristine nature of the ephemeral wetland.
37 She has given evidence which I accept, that at the present time the level of water is now higher in, and remains longer on, the bed of the "ephemeral wetland" than had been the case prior to the undertaking by the Council of drainage works in the 70's and 90's. Throughout the 80's Mrs Coventry complained to Council concerning noxious lands on her land caused by the introduction of seeds by surface water. There were, however, occasions in the 80's when she saw no water in the ephemeral wetland area even after a long spell of wet weather. It would seem, therefore, that the 2.2 hectares retained some of its ephemeral characteristics during that period. I accept Mrs Coventry's evidence that when water rose above 8m AHD in the 80's it rose to levels higher than those to which it rose before any drainage works were undertaken.
38 Matters came to a head in 1993 when Council announced that it was proposing to construct a road link to Dowling Street with consequential drainage works. It wrote to Mrs Coventry setting out the drainage works proposed. Mrs Coventry told Council she would not give her consent to the work because she was dissatisfied with the amount and quantity of water already coming on her land and she believed the proposed work would worsen the situation. She threatened injunction proceedings. Later the threat was withdrawn when Council undertook not to connect and discharge water into a 900mm diameter drainage line constructed along Dowling Street until satisfactory arrangements were made with Mrs Coventry.
39 In a spirit of cooperation Mrs Coventry provided Council with information she had concerning the ephemeral nature of what she described at the time as the "wet basin". At that time Council suggested it would construct two basins to receive the upper catchment water and until that was done a 900mm drainage line would be constructed but not connected.
40 In May 1994 Council told Mrs Coventry it would construct two basins and a gross pollution trap on her land. Later and after discussions with Mrs Coventry Council decided to construct one artificial basin having a storage volume of approximately 260,000 cubic metres.
41 The negotiations between Mrs Coventry and Council dragged on throughout 1995. Mrs Coventry through her solicitor had expressed concern that what was proposed might cause water in the ephemeral wetland to rise to 13.5m AHD. Although this turned out to be a mistake made by her solicitor there was some justifiable concern on her part that what was proposed would cause more water to come onto her land. During this time there were discussions between Mrs Coventry and her representatives on the one hand, and Council on the other, concerning the possibility of rezoning the subject land in the context of a "land exchange" - although this matter was not pursued in the proceedings.
42 After Council had forwarded its proposal for a single detention base, Mrs Coventry signed a consent to the lodgement of a development application by Council to itself for a construction of a single basin. Development consent was granted by Council on 20 December 1995.
43 In the meantime, Mrs Coventry had taken independent advice and, in March 1996, she forwarded to Council an alternative proposal developed by Mr Boyden, an engineering consultant retained by her. Mr Boyden expressed the opinion that Council's proposal would not serve any worthwhile purpose because it would not reduce either the volume of water coming onto the subject land or the flood level likely to occur as a result. Also, he said it was not likely to improve the quality of suburban stormwater run-off.
44 Under Mr Boyden's proposal, water would be intercepted at the boundary of Mrs Coventry's land and then carried by what was described as a "thrust bore" underground tunnel from Dowling Street into Nelson Bay.
45 Although Mrs Coventry had threatened legal proceedings in 1993 and had later withdrawn the threat, it was not until March 1996 that she told Council she would not agree to any works being undertaken on her land of the type proposed by it.
46 After receiving Mr Boyden's proposal, Council undertook geotechnical investigations and identified bedrock in the underground area identified for the "thrust-bore". Council was interested enough in his proposal however, because, after he had produced a design for an amended tunnel bore, his firm was retained by Council. Mr Boyden's proposal involved tunnelling work outside the subject land and, if implemented, would have required Council to acquire easements over neighbouring land.
47 A fair reading of Council's internal memorandum makes it clear, in my opinion, that Council accepted it had a responsibility to Mrs Coventry to abate the nuisance it had caused by the drainage works undertaken in the 1970s and 1990s. It accepted what it described as the "concept" of a thrust-bore system as a possible way of abating the nuisance and spent money investigating Mr Boyden's proposed methods.
48 In December 1997, Mrs Coventry's solicitor was advised by Council that the thrust-bore proposal "did not appear viable on preliminary assessment due to environmental constraints". Apparently, there were some discussions concerning compulsory acquisition because Council told Mrs Coventry's solicitor that it could not afford the price she was asking for her land. This aspect of the dispute between Mrs Coventry and the Council was not explored before me. It is to be noted, however, that assuming, as I do, Council had the power compulsorily to acquire property for its lawful purposes, it would not have been required to pay any price Mrs Coventry asked for the land - it would have been required to pay "fair compensation" as that is relevantly understood in the Land Acquisition (Just Terms Compensation) Act 1991.
49 Although Council raised issues such as "community acceptance" and "environmental constraints", the real reason, in my opinion, for Council not implementing the proposal to abate the nuisance was the estimated cost of the thrust-bore method. Nonetheless, Council continued to use Mr Boyden's firm in an endeavour to find an acceptable solution for the abatement of the nuisance.
50 In July 1999, Mrs Coventry lodged the development application for the construction of 214 residential dwellings. The development was "integrated development" and hence Council was required to consult with relevant government departments on matters affecting the environmental impact of what was proposed. In particular, it consulted with the Department of Land and Water Conservation, prior to making a decision. Council did not make a decision within forty days and Mrs Coventry appealed to the Land and Environment Court. As I have said, the carriage of her appeal was taken over by Melaleuca in about September 2000.
51 In the course of negotiations which resulted in the Land and Environment Court granting development consent, subject to a number of conditions by consent, it was Melaleuca that propounded the wick drainage system. Council made no representations to Mr Cornwell, that it was liable for the implementation of abatement work and, in fact, Mr Cornwell has accepted that Council was at all relevant times denying liability.
52 I am satisfied on the balance of probabilities that prior to the drainage works being constructed by Council in the 1970s, very little surface water ran onto the subject land from the higher catchment area - and, in particular, that part of the higher catchment area referred to as the Seabreeze Estate. The rain that fell was, until the area was developed, absorbed within the area and became ground water, which in times of heavy rain raised the level of the ground water to above 8m AHD (the bottom of the ephemeral wetland). The extent of water covering the ephemeral wetland varied depending upon the amount and intensity of rainfall. In the absence of development in the catchment area, the ephemeral wetland would subside over a period of time and drain under the dunal area into Nelson Bay.
53 At the present time, water enters the subject land at three points - one of which is a pipe, which actually intrudes onto the subject land, and two others that are immediately adjacent to the subject land. A consequence of the drainage work undertaken by Council in the mid 70's and 90's is that now a significant amount of water enters the subject land carrying nutrients and other deleterious substances whereas previously all water that entered the subject land entered underground. Moreover, as I have already said, there is now more water going onto the subject land than prior to the drainage works being constructed.
54 I find that the work undertaken in the 70's was necessary to be undertaken and was constructed with due care. Melaleuca has submitted that, at that time, drainage basins could have been constructed and, accordingly, the flooding of Mrs Coventry's land was not the inevitable consequence of the exercise by Council of its statutory powers. It is accepted that the thrust-bore system and the wick drainage system were not feasible options in the 70's - although both were in the 90's. I have had regard to the circumstance that it is Melaleuca's case before me that drainage basins would not have been appropriate for the reasons advanced by Mr Boyden. However I have also had regard to the circumstance that when Mrs Coventry discovered that a pipe had intruded onto her land and it, together with another two very close to the boundary, were bringing surface water onto her land the Council promised to address the matter by developing a pumping system which it never did.
55 I have already referred to the circumstance that the evidence is unclear as to what excess water reached the ephemeral wetland as a result of the drainage works undertaken in the 70's, and what amount of additional water came onto the land as a consequence of the drainage works undertaken in the 90's when, on occasions, the 900mm drainage pipe overflowed.
56 Mr Boyden thought that before any drainage work had been undertaken, about 62,000 cubic metres of water would have drained from the natural catchment to the subject land in consequence of a 1 in 100 year flood. He thought that after the drainage works had been carried out, about 76,340 cubic metres would reach the subject land - at least in a 1 in 100 year flood. This means that, on his estimate, there would be an increase in volume by approximately 18%. The experts disagreed about this but only Dr Joliffe did further calculations and I record I accept those calculations. His calculations led him to the conclusion that some water reached the ephemeral wetland area 25% of the time prior to the development of the Seabreeze Estate catchment area, and that after Council's drainage works in the 70's and the 90's, some water is present in the ephemeral area more than 90% of the time. Moreover, Dr Joliffe thought that, prior to drainage works being undertaken, the maximum height of water in the basin would have been about 10m AHD, whereas, as a consequence of the work undertaken in the 70's and 90's, he believes that not only would there be some inundation above 8m AHD more than 90% of the time, but the maximum level would now be about 12.6m AHD. But the evidence does not permit of a determination of how much water now covers the 8mm AHD bed 90% of the time or how frequently it rises to 12.6 mm AHD.
57 In my opinion, the plaintiff has established that not only is more water coming on to the subject land by reason of the Council's drainage work, but it is now coming over the surface whereas previously it entered underground and caused inundation only when the underground level rose about 8m AHD.
58 Moreover, I find the quality of water that now enters the subject land has been reduced because of surface water from Seabreeze Estate coming on to it. Gross pollutants enter the subject land via surface water and nutrient pollutants enter the subject land by surface water and, to some extent, by underground water. I accept, however, that the Council has already allocated money to install gross pollution traps and they will be installed in the course of the development being implemented.
59 Before turning to the submissions advanced by both parties, it is relevant in my opinion to note that even had there been no residential development in the Seabreeze Estate catchment area, the inundation of the ephemeral wetland to a little over 10m AHD at its maximum meant that any development of the subject land would have had to accommodate the circumstance that 2.2 hectares of it could not be built upon unless significant works were undertaken to accommodate the natural subterranean underground water coming on to the land.
60 As I have mentioned above, although reference has been made to possible "environmental constraints", what deterred the Council from giving effect to the thrust-bore system was the financial cost (not "environmental" or "community" concerns). The general manager has given evidence to the effect that if an order were made, moneys would be found to undertake abatement work provided sufficient time were given. As I have said, on the evidence before me, I do not think that such a project, properly undertaken, would contravene the provisions of the Environmental Planning and Assessment Act 1979 and/or the Local Government Act 1993.
61 At the present time, there are detectable amounts of phosphate and/or total petroleum hydrocarbons in water entering the subject land through the Council's drainage system. The evidence would appear to indicate that they have exceeded the guidelines by only a small amount, but, in my opinion, they ought not be characterised as being insignificant - as evidenced by photographs tendered in evidence. I do not accept the somewhat colourful description given by one witness that the nutrients entering the land have turned the ephemeral basin into a "duckpond".
62 As I have earlier said Melaleuca has submitted that Council cannot avail itself of statutory protections against liability either by (s241 or s733) if works it undertook could cause water to be "polluted" within the meaning of the Clean Waters Act 1970 and cognate legislation. In my opinion the circumstances that water is found to be "polluted" by reason of the definition of pollution in the Clean Waters Act would not necessarily conclude the matter against the Council. The definition in the Clean Waters Act embraces even a miniscule amount of what is ordinarily understood to be pollution. It would not necessarily follow, in my opinion, that immunity would lost and an equitable remedy granted simply because there was a detectable amount of phosphates and/or total petroleum hydrocarbons found in water entering the subject land. Moreover, the denial of a remedy in the present case would not have the consequence that the relevant regulatory authority, the EPA, could not police its own legislation.