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5 Does the Oreti River have Outstanding Values?

  1. In this section of our report we systematically evaluate the intrinsic and amenity values of the Oreti River to determine which of these are “outstanding”.
  2. t is pertinent to note here that although we consider that relatively few intrinsic or amenity values of the river are outstanding, many of the other values that we appraise here would be protected by the provisions of the water conservation order that we have recommended. For example we consider the native fishery values of the catchment to be significant but not outstanding, but the order we recommend will help protect those native fishery values by retaining flows and providing for passage through the river system.

5.1 Wild and Scenic Values

  1. We endeavoured to assess whether the upper Oreti has outstanding wild and scenic values. In saying this we acknowledge that none of us are expert in judging such values, and we heard no real expert evidence that did so. Accordingly our conclusions are primarily subjective.
  2. The upper Oreti is certainly a visually impressive valley. Formed by a glacier, it is conspicuously U-shaped, surrounded by mountains that are clad by beech forest at lower altitudes giving way at higher altitudes to sub-alpine vegetation and bare tops. The river itself is visually quite striking, particularly with regard to its classic pool-riffle-run reaches and for its remarkably clear waters. We can well imagine that to a trout angler or other visitor the river and its valley may for very good reason appear to be scenically outstanding. Indeed, many of the anglers who spoke to us said as much.
  3. We do not consider that the upper Oreti catchment can be described as “wild”. There are several reasons for this. Much of the upper valley is easily accessible by road. Many of the flats beside the river are farmed, albeit extensively, and the riverbed is in places accessed by grazing stock and encroached upon by introduced weed species such as gorse and broom. The river itself is an unconfined single-thread channel, with no rapids or waterfalls between narrow rock buttresses that make river channels appear “wild”13 (the upper Mohaka, Rangitikei and Motu rivers being very good examples).
  4. In a comparative context we also consider that the scenic values are nothing particularly out of the ordinary. There are many similar headwater river systems to the east of the main divide of the South Island that in our view have greater wild and scenic values than those of the upper Oreti. Many of these river valleys are already protected in perpetuity by being part of National Parks (good examples being the headwaters of the Waimakariri Catchment in Arthur’s Pass National Park, the Travers, D’Urville and Sabine Rivers in Nelson Lakes National Park, and the Greenstone and Caples Rivers in Fiordland National Park).
  5. Accordingly we do not find the upper Oreti catchment to have outstanding wild and scenic values as, to quote the Environment Court, it is not in our view “quite out of the ordinary on a national basis”.
  6. The lower river certainly has no notable scenic values. It is a typical semi-braided river running across the relatively flat Southland Plains. It is like many other similar rivers in the south and east of the South Island.

5.2 Native Fisheries

  1. Dr Jellyman provided the substantive evidence on native fisheries values. He said that 14 native fish species, of which 10 are migratory, have been recorded from the river. Two of the migratory species – long-finned eel and giant kokopu – are considered to be in decline nationally. Apart from long-finned eels most migratory species are confined to the lower 50–60 kilometres of the river. Passage to the sea is necessary to maintain populations of migratory fish.
  2. The Oreti River provides very important habitat for long-finned eel and several galaxid species, two of which are endemic to Southland. Dr Jellyman described the Oreti’s characteristics that offer long inland range penetration and unimpeded upstream access (the best in Southland), both very important for the long-finned eel in particular, and probably also for the migratory galaxid species.
  3. Upstream reaches are dominated by relatively high densities of non-migratory southern flathead galaxias. Dr Jellyman said their food supply could potentially be threatened by didymo.
  4. Because the information about freshwater fish is incomplete, and because long-finned eel and some of the galaxid species are so widely distributed, it is difficult to be definitive about the national significance of the Oreti River’s habitat values for freshwater species. However, there are no known features of the native fish populations of the river that we consider make it “outstanding” in a national context. While both long-finned eels and giant kokopu are “in decline”, both species are widespread throughout much of the country. The Oreti is important as a habitat for these species and others, but this does not make it outstanding.
  5. Mr Skerrett explained the significance of native fish species to Ngāi Tahu who regard them as a taonga. This cultural significance has also been recognised by the Crown in Schedule 97 of the Ngāi Tahu Claims Settlement Act 1998 which lists taonga species. Our conclusion is that, at the very least, the quality of the Oreti River as habitat for long-finned eel strongly contributes to the river’s outstanding values in accordance with tikanga Māori, which we discuss later.

5.3 The Brown Trout Fishery

  1. The nub of the applicant’s case was that the brown trout fishery, and the associated recreational opportunities that it provides, are outstanding and so merit protection by a water conservation order. We agree on both counts for the reasons now discussed.

5.3.1 The Comparative Value of the Brown Trout Fishery

  1. We have already summarised compelling evidence that both the size and numbers of brown trout in the upper Oreti make it exceptional on a national basis. In particular, the average size of brown trout, at just over 6 lbs, is over 10% greater than in ten other highly valued South Island headwater fisheries studied by NIWA in 1989–92.14 The numbers of large trout now being recorded, at some 30 per kilometre, make the upper river one of the most productive trout fisheries nationally that are not fed by a lake or springs.
  2. Evidence was also provided that trout densities and biomass in the upper river have increased nearly four-fold in the last 15 years or so. This was attributed in large part to the “catch-and-release policy” imposed by Southland Fish and Game in the early 1990s. While we have no quantitative evidence to support this assertion, it seems probable that the policy has been an important factor in the recorded increase.
  3. Some of the submitters who opposed the application questioned the value of the brown trout fishery of the upper Oreti, saying for instance that while the fishery was good it was not exceptional for Southland. No evidence was led to lend any significant substance to this view.
  4. Referring back to the case law, the Environment Court concluded “that to qualify as outstanding a characteristic would need to be quite out of the ordinary on a national basis.” We think that this is clearly the case for the upper Oreti. Both the average size of the brown trout present, and their numbers and biomass, place the river quite out of the ordinary nationally. Accordingly, we find that the upper Oreti does support outstanding habitat for brown trout, and as such qualifies for protection by a water conservation order.
  5. Both the original and amended applications also sought protection of named tributaries of the upper Oreti. These included the Weydon Burn, the Windley River and all other tributaries upstream of a point near Lincoln Hill.
  6. We consider that all these tributaries contribute to the outstanding brown trout fishery. In particular we note that shallow groundwater and small stream flows are very important for maintaining flows and water quality in the river, and that the lower reaches of the Windley River hold some large trout.
  7. We carefully considered whether the above reasoning also applied to the Weydon Burn, for which the evidence was initially less clear. This catchment enters from the west further downstream of the other significant headwater tributaries, and much of it is farmed. The stream does hold some brown trout, but is relatively stable and already affected by didymo.
  8. In his second brief of evidence, Mr Rodway presented information from nine electric fishing surveys carried out in Weydon Burn and a tributary, Starvation Creek, between 1980 and 1997. These showed often high numbers of juvenile brown trout, resident galaxids, bullies and long-finned eels in both streams. Mr Rodway also said there are some resident brown trout in deep pools in the lower reaches, and that the stream is an important trout spawning and juvenile rearing habitat.
  9. We have decided that Weydon Burn contributes sufficiently to the outstanding brown trout fishery of the Oreti River to merit protection by a water conservation order. This is primarily because of its value as trout spawning habitat and as a nursery for juvenile trout.

5.3.2 The Value of the Fishery to Anglers

  1. In broad terms we heard two streams of evidence from witnesses for the applicant about the value of the brown trout fishery of the upper Oreti to anglers. Mr Unwin put the values of the Oreti River in a national context using national survey data that ranked the Oreti fishery in comparison with others around the country. Individual anglers spoke, often passionately, about what makes the upper Oreti special for them. We heard relatively little evidence, however, about the angling amenity of the river downstream of Rocky Point.
  2. As we have already outlined in summarising Mr Unwin’s evidence, angling participation rates are highest in the lower South Island, and in Southland in particular. The two national angling surveys carried out for Fish and Game in 1994–96 showed that of the 152,900–157,400 angling days in the Southland region, about a third were spent on the “world class” Mataura River, 16-20% of days were spent on lake fisheries, and 13–18% of days were spent on the Oreti River. This represents 20,600–27,200 angler days per year.
  3. Nationally the Oreti River is well established as New Zealand’s third most heavily fished trout river, and is headed as a trout fishery only by the internationally renowned Mataura and Tongariro Rivers. It was also the seventh most heavily fished river nationally, with others ranking more highly being the major Chinook salmon rivers of Canterbury – the Waimakariri, Waitaki and Rakaia Rivers – and the Clutha River.
  4. The estimated use of the upper Oreti in 2001/02 was 2,700 plus or minus 800 anglers per year. This estimate, based on a survey of fishing licence holders in New Zealand, very likely underestimates the contribution made by overseas anglers who were not included in the survey and who are about 12 times more likely to fish the upper Oreti than their New Zealand counterparts. This was supported by the evidence of Mr Sutherland, who during an extensive survey of the river in 2000/01 spoke to 191 individuals, of whom 59% were visiting from overseas.
  5. The upper Oreti ranks 10th for usage of the 218 back country and headwater fisheries nationally. Its use is very similar the Ahuriri, which is already protected by a National Water Conservation Order (for its wildlife habitat as well as fisheries values). The ranking is likely to be higher if overseas anglers are taken into account, as they are known to favour high-quality back-country fisheries, such as provided by the Greenstone, Caples, Ahuriri and Oreti.
  6. We have summarised the evidence of those anglers and fishing guides who spoke about why they rate the upper Oreti so highly. The characteristics that they spoke so enthusiastically of include:
    • The peace and solitude of the area, along with the scenic qualities of the environment and the relatively low numbers of anglers present.
    • The presence of substantial numbers of large brown trout, including trophy fish.
    • The extremely clear water, associated with being able to spot, stalk and fish to individual fish.
    • Relatively easy access to and along the upper river.
  7. The Southland and Otago Fish and Game regions are blessed with some very highly rated trout fisheries, of which the Oreti River is one. Other highly rated rivers include:
    • The Mataura River immediately to the east. It is protected by a National Water Conservation Order made in 1997. The river holds only brown trout, which are much smaller on average than in the Oreti, but provides high-quality angling along much of its length. It is the most heavily fished brown trout river in the country.
    • The Mararoa River immediately to the west of the Oreti has been badly affected in it upper reaches by didymo. According to Mr Rodway it remains a good trout fishery, mainly for rainbow trout, below about Key Bridge.
    • The Greenstone and Caples rivers, which form a tributary entering the south west of Lake Wakatipu. Both hold predominantly rainbow trout, access is by foot and the rivers are true wilderness fisheries, being much more remote than the Oreti. A ballot system is in place. Some witnesses said the fishery has declined in recent years.
    • The Eglinton River which runs alongside State Highway 94 north of Te Anau. Access is quite easy, and the river contains mainly brown trout with some rainbow trout. The river is usually clear, and to use Mr Bell’s words, has “scenic grandeur”.
    • The Waiau River, which is the outlet of Lake Manapouri. The river is highly rated but access is limited and the river cannot be waded.
  8. On a national basis we heard evidence from witnesses such as Mr Bowler and Mr Kastner that the river most comparable with the Oreti is the Ahuriri.
  9. We also heard that the Oreti River ranks highly on an international basis. Several anglers with wide experience of fishing rivers in some of the more remote and challenging parts of the world said there was no brown trout river that matched their experience of the upper Oreti.
  10. In her closing submissions Ms Baker also submitted that there are economic reasons for the Oreti River to be protected, saying it is logical to assume it receives a significant proportion of the “fishing dollar” spent nationally. While this may be a reasonable assumption, no expert evidence was provided on this matter and so we make no finding about it.
  11. In conclusion, we find the weight of evidence strongly supports the applicant’s assertion that the upper Oreti provides outstanding angling amenity as a brown trout fishery. The river has a national and international reputation as a challenge to skilled anglers, providing very large fish that can be spotted and fished to.
  12. The evidence also indicates to us that the entire Oreti River brown trout fishery is outstanding in a national context. While it is the value of the headwater fishery that was strongly emphasised by the applicant and their supporters, the whole river undoubtedly supports a highly valued trout fishery, as indicated by its status as the third most popular trout fishery nationally. However, evidence about angling amenity focused on the upper river above Rocky Point, and we have insufficient evidence to determine if the entire river provides outstanding angling amenity.

5.3.3 The Extent to Which the Fishery is Affected by Didymo

  1. The impact of the recently introduced diatom Didymosphenia geminata (didymo) on the outstanding angling amenity of the upper Oreti was discussed by several witnesses, most notably Mr Jarvie, and we asked questions of a number of others. This is because we wanted to ascertain the extent to which the outstanding brown trout habitat and the outstanding angling amenity could be adversely affected or degraded by didymo.
  2. First recorded in New Zealand in 2004 in the Mararoa River, the catchment immediately to the east of the Oreti River, didymo has now been recorded in over 50 South Island rivers. Further incursions are being recorded regularly. Didymo has been present in the Oreti since October 2005.
  3. We asked a number of witnesses for the applicant and submitters how didymo affected the angling experience in the upper Oreti. A typical answer was given by Mr Todd, who said that it affected the angling experience, but not the catch rate. Overseas anglers, particularly those from the USA where didymo has become a major problem, were particularly sensitive to its presence.
  4. In early stages of colonisation, the microscopic diatom cannot be detected with the naked eye. Didymo aggregations grow rapidly, however, and at their worst, form dense brown mats up to 20 cm thick in the beds of the rivers; these are aesthetically disgusting, and reduce habitat for the benthic invertebrates on which trout (and many native fish) predominantly feed. At such levels of infestation didymo could affect trout growth rates and carrying capacity, affect the angling experience and success by fouling gear and reducing aesthetic values, and potentially affect water quality parameters such as pH and dissolved oxygen levels.
  5. Unlike many other algae, notably filamentous green algae, didymo does not need significant levels of plant nutrients present in the water to form dense growths. This is part of the reason it has been so “successful” in colonising pristine headwater rivers, which generally have very good water quality, with low levels of nutrients present. The Oreti is one such river. According to Mr Sutherland the Oreti does occasionally have filamentous green algae growths during spring, but these are quickly removed by floods or freshes.
  6. Like other algae, didymo is sloughed off its substrate during high flows. In broad terms, the more stable the substrate and the more stable the flow, the greater the potential for didymo to form the large mats that are so degrading of natural habitat values. This is because stable substrates do not become mobile during freshes and moderate floods, and is why didymo has caused the greatest concern in rivers with stable, strongly embedded substrates. Notable examples include the Mararoa, Clutha, lower Waitaki and upper Buller Rivers. All these river catchments are at least part-fed by lakes and so flows tend to be relatively stable and the substrate becomes very embedded. In two cases – the lower Waitaki and the Clutha – flows are also regulated by hydro-electric power schemes and so floods occur much less frequently than they would if these rivers were unmodified.
  7. Fortuitously the upper Oreti does not have a stable bed. Rather it is the opposite – the bed comprises largely cobbles that would move easily during freshes and floods. Mr Jarvie told us that didymo did form extensive cover in a number of reaches of the upper Oreti during extended periods of stable low flows in 2005 and 2006. However, in January 2007 the riverbed was largely devoid of didymo (at least at levels discernable to the naked eye) due to a series of minor to medium flood events that occurred between August and November 2006. For instance at Centre Hill in the upper catchment, visual assessments of didymo showed that it decreased from covering 60–70% of the bed in winter 2006 to covering less than 1% in January 2007. Similarly, the thickness of the mats decreased from 6–8.5 mm to less than 1 mm.
  8. In the much more stable Mararoa River (where flows are buffered by the influence of the Mavora lakes), 100% cover was measured at the monitoring site in winter 2006, and 86% coverage in January 2007, at which time the thickness of the infestation was estimated to be 18.5 mm.
  9. After invasion it appears that the diatom will always remain in its microscopic presence, so there is always potential for further rapid growth. However, Mr Jarvie said that even following floods in the Mararoa River strips of didymo have remained intact against bank margins, which allows rapid recolonisation. In contrast, in the Oreti River remaining didymo only occurs as very small remnants, and so recolonisation is much slower.
  10. We did hear that Weydon Burn, which in its lower reaches has a meandering channel and a relatively stable bed, has recorded significant biomasses of didymo.
  11. Dr Hayes told us about provisional studies carried out in April 2006 by the Cawthron Institute, for Biosecurity New Zealand, on the impacts of didymo at two sites in the Oreti River and one in the Mararoa River. Didymo was rare to absent in the upper Oreti, present at moderate biomass in the lower Oreti and present at moderate to high biomass at the Mararoa site.
  12. The studies focused on invertebrate drift, which is an indicator of the density of invertebrates in a reach of river. Invertebrates such as mayflies and stoneflies are a primary source of trout food, and so their density in the drift is an indicator of food availability. Other important trout food sources include young fish, terrestrial invertebrates blown on to the surface of the water and, on occasions, mice.
  13. The results – albeit from only one limited study – did not support the hypothesis that didymo alters drift sufficiently to have negative impacts on trout growth. Indeed moderate infestations did increase invertebrate densities in drift, although insects were on average smaller. However, Dr Hayes did consider that trout would find it difficult to feed directly on invertebrates in reaches of river heavily infested by didymo.
  14. NIWA have been undertaking work on possible chemical controls to reduce levels of didymo infestation. Some of these have shown good potential for control in trial situations. However, given that the colonising forms of the diatom are microscopic, and given the already very wide (and increasing) range of infestation, we think it very unlikely that didymo can be eradicated from New Zealand, at least using current methods and technology. In our view it is now, regrettably, a feature of rivers such as the Oreti River for the foreseeable future.
  15. We have reached the following conclusions about the potential effects of didymo on the outstanding brown trout fishery of the upper Oreti:
    • In the foreseeable future didymo will always be present in the Oreti catchment.
    • Infestations are likely to be on average relatively light and generally of short duration in the upper river due to the unstable and mobile nature of the cobble-dominated river bed, which is readily mobile during freshes and floods. The greatest infestations will occur during periods of stable low flows.
    • More stable tributaries, such as Weydon Burn, are likely to become more heavily infested at times, with potential adverse effects upon fishery values.
    • In the upper river infestations appear unlikely to have significant or lasting adverse effects on trout habitat, growth or abundance. Infestations may, however, have temporary, potentially adverse effects on recreational angling values following periods of stable flows.
  16. In summary, we strongly believe that the outstanding brown trout habitat and associated outstanding angling amenity of the upper Oreti will not be affected by didymo to the extent where they could no longer be considered as outstanding. Its presence in the river is no reason not to make a water conservation order for the Oreti.
  17. We also suggest that the regrettably rapid spread of didymo throughout the South Island, and we think inevitably the North Island also, means that rivers such as the Oreti will become relatively more important in future. This is because many rivers with more stable flow regimes and embedded substrates will become more strongly affected by the diatom species. By way of example we note that didymo has recently been recorded in the Hurunui River in Canterbury. This is another highly valued headwater trout fishery, but as it is primarily lake fed and has a relatively stable bed, it seems likely that those values will be substantially eroded by the presence of didymo. In other words, we think the widespread incursions of didymo in our rivers will in future make the Oreti relatively more outstanding in a national context, than it would be without the diatom being so “successful” in many otherwise pristine or high-value environments.

5.3.4 Conclusions re the Brown Trout Fishery

  1. We have drawn three main conclusions about the brown trout fishery of the Oreti River and its headwater tributaries:
    • The river, along its length but particularly in its upper reaches, provides outstanding habitat for brown trout. We draw this conclusion because of both the very large average size, and the high densities of brown trout in the upper river. The essential elements of protecting this outstanding habitat include maintaining existing high water quality, maintaining flow characteristics including shallow groundwater inputs, maintaining the cobble-based bed of the river and maintaining fish passage throughout the river (as it is evident that migration through the river system helps sustain the headwater fishery).
    • The upper river provides outstanding angling amenity. This amenity is provided primarily by the presence of large numbers of large brown trout, with the very high water clarity allowing individual fish to be “spotted” and fished to. The amenity values present also include the relative isolation and scenic values of the upper catchment, and the limited amount of modification of the landscape that has taken place there.
    • The outstanding brown trout habitat of the river is unlikely to be significantly affected by the presence of didymo in the river. Angling amenity may be somewhat affected, albeit for only generally short periods. The comparative value of the river may increase given the adverse affects of didymo on many other highly valued trout fishing rivers in the South Island.

5.4 Wildlife Values

  1. The applicant presented relatively little evidence on the native wildlife values of the Oreti River. We heard evidence from Ms McLellan regarding black-billed gulls and from Dr Jellyman regarding native fish (which we have already discussed). This evidence was supplemented to some extent with evidence from Ms Maturin and Mr Esler for Forest and Bird.
  2. We were disappointed that the Department of Conservation, who in a letter included as part of the application had indicated their support for a water conservation order, did not submit on the application. We did, however, write to the department on 9 March 2007 seeking more information on the wildlife values of the Oreti River. A helpful response was received on 28 March, and was made available to all interested parties at the hearing.
  3. There are some significant populations of native species, some of which are endangered, living and breeding on and in the Oreti River. The variability of these populations in both space and time makes it difficult to judge whether the presence of these populations gives the Oreti River outstanding characteristics as habitat for terrestrial or aquatic organisms, which is the relevant criterion under s199(2).
  4. The species for which most evidence was led was the endemic black-billed gull (Larus bulleri) which is listed as a threatened species in serious decline in the New Zealand threat classification system. The evidence presented to us is that currently there are about 80,000–100,000 breeding black-billed gulls nationally, and that the numbers of these gulls have dropped significantly over the last 20–30 years. It is estimated that 70–80% of these birds breed in Southland, with the greatest numbers being recorded from the Aparima and Oreti Rivers. Numbers of birds and colonies on each river vary substantially from year to year. On the Oreti River, colonies are found along much of its length apart from the lowest reaches and the upper headwaters.
  5. Clearly, the Oreti River (along with the Aparima River) provides critical habitat for the threatened endemic black-billed gull. Regardless of all the variability of numbers over time, the river bed contains some of the largest breeding colonies nationally and a very sizeable proportion of the breeding population nationally, quite possibly more than 30% in some years. Significantly, some of the Oreti breeding sites are not only large but relatively secure from threats, a most important characteristic for a declining national population.
  6. We accept the submission of Ms Baker that case law supports the assertion that at least some parts of the Oreti River provide outstanding wildlife habitat. In particular the 5% “threshold” of the national population of an endangered species suggested by the Environment Court in its findings on the Rangitata water conservation order, is far exceeded in the case of the black-billed gull population in the Oreti.
  7. Ms McLellan told us that over the last 30 years, colonies of black-billed gulls have been recorded on the river between about 15 km of the mouth to close to the confluence of the Windley River. The colonies known to Ms McLellan from the last ten years’ observations were mostly located between Centre Bush (about 40 kilometers inland) and Mossburn, with one “outlier” at Coal Hill (about 130 kilometers inland). However, neither the applicant nor supporting submitters established exactly how important the river upstream from Mossburn was for black-billed gull habitat.
  8. The significance of the Oreti River for other native birds is more difficult to establish. The black-fronted tern is a nationally endangered species for which the Oreti appears to offer significant habitat, judged by Mr Esler’s estimate of “several hundred birds” seen nesting by him, and some survey information from the 1990s cited by Ms Maturin. However, there is not enough specific information to support Ms Maturin’s assertion that “it is possible that the Oreti still provides habitat for a significant proportion of the Southland population of black-fronted tern, and possibly the New Zealand population”, to the extent of our agreeing that the Oreti is nationally outstanding habitat for black-fronted tern.
  9. It is very likely that the Oreti River provides good habitat for populations of several other native birds, some of them endangered, but again there is not enough information to show that the Oreti provides nationally outstanding habitat for these species.
  10. We have concluded that the Oreti River provides outstanding habitat for black-billed gulls, at least in the section downstream of Rocky Point. The outstanding habitat may extend further upstream than Rocky Point, but there was insufficient evidence to determine this.
  11. We note also that, as discussed in the section of native fisheries above, many of the species identified in the evidence of Forest and Bird are identified in Schedule 97 of the Ngāi Tahu Claims Settlement Act as taonga species – in other words the species are culturally significant and valued by Ngāi Tahu.

5.5 Values in Accordance with Tikanga Māori

  1. We heard evidence from Mr Skerrett and Mrs Loose on the value of the river to tangata whenua. This put into context how the natural characteristics and outstanding values of the river, as discussed above, complement Māori perspectives.
  2. Mr Skerrett explained that Ngāi Tahu has a long association and involvement with the Oreti catchment and it remains culturally significant. The Crown recognised this significance in the Ngāi Tahu Claims Settlement Act 1998. Schedule 50 of the Act is the Statutory Acknowledgement for the Oreti River.
  3. In describing the significance of the Oreti River to Ngāi Tahu, Mr Skerrett explained the importance of the entire catchment and the waters of the Oreti from its source to the coast before emphasising the importance of the upper parts of the catchment.
  4. Continuity from the mountains to the sea (ki uta ki tai) is essential for ensuring the well-being of a waterway. This is particularly important because, as Mrs Loose explained, Ngāi Tahu conceptualisations recognise that water is the provider and sustainer of life, and the condition of waterways reflects the health of Papatūānuku (Earth Mother) and consequently the health of the ecosystems.
  5. We note that in terms of significance it is difficult and not really possible to undertake a comparative analysis examining the relative significance of the Oreti with other rivers. While it is generally agreed that the Waitaki, as the ancestral river of Ngāi Tahu, is paramount to them, concepts of national and regional significance are difficult to apply to cultural settings where significance is accorded by the respective whānau, hapū and rūnanga. With respect to this application for a water conservation order, it is important to note that Mr Skerrett presented on behalf of all four papatipu rūnanga in Murihiku and was supported in his submissions by Te Rūnanga o Ngāi Tahu, the iwi authority for Ngāi Tahu as recognised in the Te Rūnanga o Ngāi Tahu Act 1996. Mrs Loose, as a member of Ngāi Tahu Whanui, presented similar evidence.
  6. Mr Skerrett emphasised that protection of the mauri of a resource is the fundamental management principle for Ngāi Tahu. The presence of taonga species (both fish and wildlife), the relatively unmodified upper catchment, evidence of past occupation in the form of archaeological sites and remains, the continuity of flow in the waterway from its source to coast, and high water quality are factors that enable us to conclude that the mauri of the Oreti River, especially in the upper catchment, is robust and vibrant. We note that, at least in part, all of these factors are able to be protected by the provisions of a water conservation order. While each of these factors when considered individually may fail to pass the test of being outstanding, collectively they represent grounds for our deciding that the main stem of the Oreti is outstanding for values in accordance with tikanga Māori.

13 There is one short area at Three Kings where the river flows briefly between rock buttresses.

14 While this study only compared South Island rivers, we suspect the comparative results would be no different if North Island headwater brown trout fisheries were included. This is because generally North Island rivers do not sustain populations of large brown trout as their waters are on average too warm. Rather, headwater fisheries are dominated by rainbow trout, sometimes supplemented by smaller numbers of brown trout.

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