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3 Potential Water Bodies of National Importance

The Water Bodies of National Importance Working Group was tasked with the completion of seven sub-projects. Each would develop a method for identifying water bodies of national importance for that value and a potential list. [A water body has been defined as a river, stream, lake, wetland or groundwater resource.] Most of the projects have developed methods and identified initial lists of water bodies or catchment areas that are of potential national importance. The data sets available to develop the lists have been of varying quality. Projects have been undertaken and potential lists determined for the following values:

  • natural heritage
  • recreation
  • tourism
  • energy generation
  • industrial and domestic use
  • irrigation.

The Maori Reference Group advised that it was inappropriate for individual water bodies to be identified as nationally important for Maori cultural values. Identification of individual water bodies is inconsistent with the view that all water bodies are important to Maori for spiritual, physical and customary reasons. A methodology for determining water bodies of cultural and historic heritage value has been developed, however an initial list of water bodies is yet to be produced.

3.1 Methods used

Methods appropriate for each value have been developed. No common method of determining importance for the different values has been developed, due to the different nature of the values being considered. This has led to some projects identifying relatively few water bodies (eg, 21 water bodies that contribute greater than $5 million of farmgate gross domestic product by supplying irrigation water have been identified), while other projects have identified many water bodies. For example, over 300 water bodies have been identified as potentially nationally important for natural heritage.

Consistent practices were adopted for each of the projects as follows:

  • A common spatial framework for recording information (catchments and large sub-catchments) was developed by the National Institute of Water and Atmospheric Research (NIWA).
  • Consistent timescales across sub-projects (potential development within 20 years).
  • Consistent units to describe national importance as appropriate (net present value and gross domestic product).

Although water bodies have been identified on a catchment basis, some projects have identified water dependent values at different scales. For example, the energy sub-project has identified entire catchments, which in some cases include a number of individual water bodies. This does not imply that the whole catchment is important for hydroelectricity generation. Some of the individual water bodies within the catchments have been identified for other values.

At this stage the purpose of the work has been to develop methods and criteria, and identify potential water bodies, rather than identifying areas of potential conflict or complementary uses. It is premature to align the lists and rank the water bodies at this stage.

3.2 Natural heritage (biodiversity and geodiversity)

The criteria for determining national importance were based on identifying the minimum set of water bodies required to achieve the national policy goals for natural heritage protection set out in the Purpose ["The preservation of representative samples of all classes of natural ecosystems and landscapes which in the aggregate gave New Zealand its own recognisable character."] of the Reserves Act, and the Objectives ["Protect a full range of remaining freshwater ecosystems and habitats ... using a range of appropriate mechanisms."] of the New Zealand Biodiversity Strategy for freshwater. Natural heritage includes biodiversity (ecosystems and species) and geodiversity (water body dependent features and geothermal systems).

3.2.1 Approach for biodiversity

Department of Conservation developed a biogeographic framework to help define the full range of natural diversity in freshwater systems. The framework identifies 29 geographic units or zones based around catchment boundaries. The units are likely to have experienced similar catastrophic disturbance histories (eg, glaciation or volcanism), have shared recolonisation source populations and pathways, and the same geographic barriers to the dispersal of freshwater biota.

The candidate list of water bodies of national importance for biodiversity values was calculated from a set of 4706 river catchment units. The work does not yet identify separate lakes and wetlands. The candidate list was produced on the basis of one or both of two rules:

  1. The site was listed in the minimum set required for representation of 100 percent of the river classes, and listed among the top ten sites ranked by natural heritage value within the biogeographic unit.
  2. The site contained special features (ie, threatened species, floodplain forests), or was connected to a nationally important wetland or estuary.

A wide range of river types were required to fully represent different river systems. The candidate list attempts to cover the full range of biodiversity, including at least 38 species of fish, approximately 70 aquatic bird species and thousands of endemic invertebrate species.

Assumptions and limitations

  • The list does not fully meet the goal of the New Zealand Biodiversity Strategy - to protect a full range of biodiversity values. Meeting this goal could require the protection of many additional rivers and sub-catchments.
  • Minimal weighting has been given to connectivity and buffer functions of rivers to nationally important lakes and wetlands.
  • On the West Coast of the South Island, Fiordland, and East Cape North Island, available data on the distribution of introduced fish species is sparse. Identification of systems free of introduced species was unlikely.
  • Presence/absence data used for aquatic birds does not differentiate between major populations and single sightings.
  • Some major catchments had to be listed because the sections containing values of national importance are found in the lower catchment (eg, mouth of the Waikato River).
  • The analysis does not consider groundwater systems or communities.


A total of 177 whole catchments and 57 sub-catchment units were identified as the most valuable rivers for sustaining New Zealand's freshwater biodiversity. These units represent just over 5 percent of the units that were assessed and account for an average of 76 percent of the range of river classes present in New Zealand. An additional 45 catchments were identified as containing sections of river, special features, or populations of threatened species that were also of national significance. With the inclusion of these, the lists covers almost 90 percent of river environments and a viable range of key sites for most threatened species. The final candidate list therefore took a combination of the most natural sites, catchments that made the greatest contributions to the range of river environment classes, and systems with significant populations of threatened species. [See Appendix 1 for details.]

Further work to be completed

A more comprehensive list that includes nationally important wetlands, lakes estuaries and groundwater communities is yet to be completed. This is planned to be completed by February 2005.

3.2.2 Approach for geodiversity

The New Zealand Geological Society has been publishing and refining a National Geopreservation Inventory since 1988. The inventory identifies and ranks geological and geomorphological features according to their relative significance and vulnerability to damage, and has been used extensively in RMA planning and prioritising. Department of Conservation (DoC) has selected a subset of those geodiversity features and geothermal systems that are dependent upon associated water body condition and functioning, and which were ranked as either nationally or internationally important.

Assumptions and limitations

  • Features of international importance are assumed to also be nationally important.
  • The candidate list does not include all features that might be vulnerable to the development of high dam impoundments, but this could be incorporated when the sites of potential dams are known.
  • The approach using expert panels of professionals in iterative evaluations is assumed to have progressively identified and ranked the most important elements.
  • Additional peer review of the candidate list is required.


We identified 81 geodiversity features, karst/cave or geothermal systems of national importance which were vulnerable to changes in the management of water bodies. Several of the cave and karst systems contain well known features that are also individually ranked as nationally important. These are referred to in Appendix 2. The highest concentrations of these are in the West Coast, Canterbury, Bay of Plenty and Waikato regions.

Further work to be completed

The geographic clustering of several types of systems and features reflects New Zealand's underlying geological regions. There is potential for bias based on the geographic distribution of experts. Peer review and refinement will be possible as the underlying inventories become web-based.

3.3 Recreation

Ministry for the Environment completed three strands of research into recreational activities associated with water bodies:

  • a national telephone survey to determine how and where freshwater is used for recreation by the general public in New Zealand
  • an internet-based online survey targeted at recreational organisations with an interest in freshwater
  • a review of existing information including NIWA angling surveys (2002, 1994), Wetlands of National Importance (1978), Wild and Scenic Rivers of National Importance (1982), Freshwater Recreation in New Zealand (2003), Water Conservation Orders, and anecdotal information about whitebaiting.

A candidate list of water bodies was generated from the three different sources of information. The numbers of responses within each recreation category were ranked for the telephone and internet survey information. The top water bodies for each of the existing information sources were identified, along with the water bodies subject to Water Conservation Orders. The water bodies have not been ranked.

Assumptions and limitations

  • Some of the initial list (survey, angling and whitebaiting information) is based on numbers of people using water bodies for recreational activities. This approach assumes there is a correlation between the number of people who visit a water body and its value for recreation. Under this approach the very special and remote places that are not highly visited may be under represented.
  • Some of the initial list is based on dated reports or unclear information.
  • Comparison across the different sources of information may not be a valid approach.


A total of 106 water bodies were identified as potentially nationally important for recreational use. See Appendix 3 for details.

3.4 Irrigation

The Ministry of Agriculture and Forestry led a process that identified a list of water bodies that support large areas of irrigation throughout New Zealand, or are under active investigation to supply new irrigated areas in the next 20 years. The aggregate area irrigated from each water body was used as the initial criteria for determining which water bodies were of national importance for irrigation. The potential irrigated areas were taken from a survey of the 21 community scheme development proposals currently being investigated.

Land use of the irrigated land was determined using AgriBase and local knowledge to identify the farm types within the irrigated areas. An assessment was also made of alternative uses for the land if it was not irrigated.

The net farmgate returns were determined for irrigated and dryland farm types throughout New Zealand. These were based on 2002/03 prices and include adjustments for changes in farm type and scale.

The water bodies have been valued for the additional Gross Domestic Product (GDP) produced at farmgate from irrigated farms, minus the GDP that would be produced if the same land was in dryland farm types. The result is an indication of the net contribution of irrigation from each water body to farmgate GDP. A threshold value of $5 million annual farmgate GDP was adopted for this project. The water bodies above this threshold represent 78 percent of the total irrigated area in New Zealand and produce 62 percent of the total economic output attributed to irrigation.

Assumptions and limitations

  • The basis of determining national interest was total net GDP from the presence of irrigation. Value estimates are at the farmgate. Flow-on impacts through the economy are not included in this analysis.
  • Tributaries from which water is taken for irrigation before it reaches the water body are assigned to the destination water body. The results are presented as being attributed to the whole catchment.
  • The list is based on aggregate farmgate GDP generated from the supply of irrigation water from the particular water body. Water use information is not available to calculate the marginal return from each additional unit of water.
  • The values identified for current irrigation exist alongside the other current values from those water bodies. Potential for irrigation from water bodies may be able to be realised without the loss of other values or indeed may create other benefits for those values.
  • The potential area of irrigation and therefore of the value of some water bodies for irrigation is limited by existing legislative conditions. For example, new water abstractions are limited by existing water conservation orders on several water bodies.


A total of 21 water bodies currently produce over $5 million of farmgate GDP by supplying irrigation water. Twelve of these have potential for more development that would produce additional farmgate GDP, and there is one other river not on the initial list that is also being investigated for irrigation development. See Appendix 4 for details.

3.5 Energy

3.5.1 Hydroelectric

The Ministry of Economic Development commissioned East Harbour Management Services, to assess New Zealand's potential hydroelectricity developments with a high to medium confidence level of proceeding over the next 20 years. Potential developments were combined by catchment and the catchments ranked. The Ministry also collated information on existing hydroelectric generation by catchment.

Assumptions and limitations of the East Harbour Management Services Report

  • The report has drawn on existing, publicly available information only. In some cases this information is dated which will affect the confidence that can be placed on it. No new surveys of potential hydroelectricity developments were undertaken. In addition, there are likely to be a number of generation opportunities being investigated by interested parties (usually developers or potential developers) that the authors will not be aware of.
  • The report identifies potential hydroelectricity developments - the potential developments listed have not necessarily been proposed or planned. Development would still be subject to gaining access rights, standard Resource Management Act and Conservation Act processes, and any other relevant legislative requirements.
  • Judgement of whether a potential hydroelectricity development has a high to medium probability of proceeding has been undertaken by the consultant, based on a number of criteria further described in the report. The consultants note in the report that this judgement is very subjective. In general:
    • potential developments in national parks have been excluded from consideration
    • potential developments covered by water conservation orders have not been excluded from consideration as water conservation orders are able to be modified under the Resource Management Act, for example if the outstanding values for which they were protected are no longer present. However, these potential developments have generally been listed as 'prohibited' and the presence of water conservation orders has been noted
    • most potential developments in the conservation estate have been excluded because of the high potential adverse effects. However some have been included where, in the consultants view, there is a possibility that the potential development might proceed. Some developments listed are not possible under the Conservation Act, given the specially protected status of the areas in question. The report does not always note which potential developments are located in the conservation estate.


The Ministry of Economic Development set generation of 230 GWh per annum in any one catchment as a threshold for national importance. This threshold was decided upon as it represents one percent of New Zealand's current hydroelectric resource, a proportion that the Ministry considers significant. However, this is essentially an arbitrary judgement and could be re-evaluated. Any catchment that has greater than 230 GWh per annum of either existing or potential generation was therefore identified as potentially nationally important.

Seven nationally important water bodies for existing hydroelectric energy generation were identified, along with ten potentially nationally important water bodies for potential hydroelectric energy generation. See Appendix 5 for details.

3.5.2 Geothermal

The Ministry of Economic Development collated information on New Zealand's existing and potential geothermal resource for electricity generation. Potential electricity generation from geothermal fields was derived from the East Harbour Management Services 2002 report, Availabilities and costs of renewable sources of energy for generation electricity and heat. For purposes of consistency, the same 230 GWh threshold for national importance was used.

Three nationally important water bodies for existing geothermal energy generation were identified, along with ten potentially nationally important water bodies for potential geothermal energy generation. See Appendix 5 for details.

3.6 Industrial and domestic uses

The Institute of Geological and Nuclear Sciences Limited was commissioned by the Ministry of Economic Development to attribute economic values to catchments in relation to the water supplied for industry and domestic uses. The work was carried out in four stages:

  1. acquiring water allocation information from resource consent databases and attributing the water to various uses
  2. determining the proportion of the allocation that is actually used
  3. attributing an economic value to a unit of water for each use
  4. calculating the value of domestic and industrial water for each catchment.

Projections of future domestic water use were made by multiplying current water use by the projected growth rate in regional populations (between 2001 and 2021). These projections of future domestic water use were used to rank potential water bodies of national importance. Projections of future industrial water use were not made.

Assumptions and limitations

  • Information on water allocation could only be identified where there was an individual consent. Industry will often take water from municipal supply, rather than having an individual resource consent. It was assumed that 76 percent of municipal water was allocated to domestic uses and 24 percent of municipal water was allocated to industrial uses. This assumption was based on the Institute of Geological and Nuclear Science Limited's surveys of water suppliers in six districts. However, these percentages were based on limited data and varied considerably among locations.
  • Most of the information on consents was collected in 1999. Some of the consent information was incomplete; for example, some consents do not specify use or they contain multiple uses.
  • It was assumed that a usage/allocation ratio of 46 percent was typical for domestic water supplies, and a usage/allocation ratio of 40 percent was typical for industrial water supply. Again, these percentages were based on limited data and varied considerably among locations.
  • For the purposes of this work, 'total value added' figures of water for various industry uses (derived in a 2001 report to the Ministry of Agriculture and Forestry by Ford et al 2001) were adopted for valuing industrial water use. There are a number of weaknesses associated with this approach:
    • the use of 'total value added' as a proxy of water value is not ideal as it does not take into account the other factors of production that contribute towards the added value
    • averages of the specific uses within each industry category were used which may not provide a good proxy for the specific use of the water. As the specific use is not detailed in the consent information, it is impossible to know.
  • There is uncertainty around the value of water for domestic use. For the purposes of this work, the economic value of water for domestic use was assumed to be $1/m3. This value was derived from a "willingness to pay for water" study undertaken in Christchurch.
  • We have not predicted water use for industry in 2021 due to the lack of estimates available on the type and location of industry in 20 years. Predictions of demands for domestic water in 2021, were based on regional population growth projections. These estimates do not take into account intra-regional population change or changes in the efficiency of water use.


As a result of the need to make significant assumptions in relation to water use ratios and water values for each use type, there is a great deal of uncertainty around the economic values attributed to catchments. Nevertheless, the economic values are still of use as a means for comparison within the domestic and industrial categories. As the 'total value added' method used to estimate value of industrial water is different to the 'willingness to pay' method used to estimate value of domestic water, the economic values should not be compared between industrial and domestic categories.

As a result the rankings of catchments are used as a proxy for their importance to the nation. The top ten surface and groundwater bodies from each list are considered to be potentially nationally important. See Appendix 6 for details.

Other alternative methods for identifying national importance include:

  • using an index system (ie, attribute an index of 1000 to the economic value of the top ranked catchment in each list and proportional values to each catchment down the list). This approach would allow us to measure relative value rather than just ranking and would also allow comparability between the industrial and domestic lists
  • use the volume of water allocation as an indication of importance. This does not take into account the varying values of different uses but would seem to allow a reasonable comparison between the industrial and domestic lists as the top ranked catchment in each list allocates roughly the same volume of water to their respective uses.

3.7 Tourism

The Ministry of Tourism led the tourism sub-project to identify a potential list of water bodies nationally important for tourism in New Zealand. Data from the 2002 International Visitor Survey was used to provide information on water-based tourism activities undertaken by visitors to New Zealand. The total number of people who reported undertaking any freshwater activity in each location was determined to identify the top eight destinations of importance for international visitors. The most popular freshwater activities for international visitors were:

  • jet boating
  • glow worm caves
  • scenic cruise
  • caving
  • beaches
  • swimming
  • white water rafting
  • fishing in rivers and lakes
  • river kayaking
  • black water rafting
  • other water sports
  • sailing
  • diving.

The Domestic Travel Survey 2001 data was used to provide information on water related activities undertaken by domestic tourists. The total number of people who reported doing any freshwater activities in each location was determined to identify the top 10 locations. The top 10 freshwater activities were:

  • rafting
  • swimming
  • sitting on the beach
  • fishing
  • other water sports
  • kayaking
  • jet boating
  • glow worm caves
  • sailing/boating
  • visiting Huka Falls.

Assumptions and limitations

  • Assumptions were made about the actual water bodies visited based on the location and the type of activity undertaken, and from discussions with regional tourism organisation representatives, local councils and tourism operators.
  • The list does not include water bodies that may be nationally important for tourism outside of the nine regions identified by the International Visitor Survey and Domestic Travel Survey, with the exception of those identified for their scenic values.
  • Information is based on 2002 data for the International Visitor Survey and 2001 data for the Domestic Travel Survey.
  • The list does not include water bodies that may be of national importance for tourism in the future.
  • The economic value of tourism for individual water bodies has not been determined.


The following nine locations were identified as important for participating in freshwater based activities by domestic and international visitors:

  • Queenstown
  • Te Anau
  • Waitomo
  • Taupo
  • Rotorua
  • Christchurch/Canterbury
  • Hanmer Springs
  • Auckland
  • Hamilton/Waikato.

A total of 81 water bodies of national importance for tourism values have been derived from those locations. In addition, 16 water bodies have been identified as they are potentially nationally important for tourism due to their significant scenic value. See Appendix 7 for details.

3.8 Cultural and historical heritage

The Ministry of Culture and Heritage has completed the first phase of the project on cultural and historical heritage values associated with freshwater bodies. Cultural heritage is defined in the International Council on Monuments and Sites New Zealand Charter as possessing historical, archaeological, architectural, technological, aesthetic, scientific, spiritual, social, traditional or other special cultural significance, associated with human activity.

The definition of historic heritage contained in the Resource Management Act 1991 was used as the definition for this project:

"those natural and physical resources that contribute to an understanding and appreciation of New Zealand's history and culture, deriving from any of the following qualities: archaeological, architectural, cultural, historic, scientific, technological; and includes: historic sites, structures, places, and areas; scientific; archaeological sites; sites of significance to Maori, including wahi tapu; surroundings associated with the natural and physical resources".

The report takes into account the relationship of Maori to water bodies from a heritage perspective. However, we have not developed a method to identify water bodies of national importance for Maori values.

We have developed criteria for identifying water bodies of national importance for cultural and historic heritage values, along with a process for completing the next phase of the work. The following criteria were developed for determining water bodies of national importance for cultural and heritage values:

  • an association with extant heritage objects, structures, sites or places
  • an association with past activities or events
  • an association with a particular community or the public at large.

In addition, three categories of values were identified - physical, historical and social. This is in recognition that places of cultural and historic value have one or more of a range of values that may include such things as historic, archaeological, architectural, aesthetic, technological, and social.

Further work to be completed

The process outlined in the Cultural Heritage Assessment Report needs to be completed to develop a list of nationally important water bodies for cultural and historic heritage values.

3.9 Maori cultural values

A fundamental difficulty with any proposal to combine Maori cultural perspectives and national perspectives is that Maori culture is whanau/hapu/iwi based. Therefore, a water body of great importance to one iwi may not be considered culturally important by another iwi. Similarly, there may be water bodies that are important to some but not all hapu and whanau groups within an iwi.

A second difficulty in assessing Maori cultural values is that many water bodies have been substantially changed in character since European settlement (eg, through changes in land ownership, drainage schemes, dam construction, pollution and the introduction of exotic species). This raises the question of whether it is the traditional Maori cultural value or the current value that should be considered as important.

The Maori Reference Group suggested that rather than attempting to identify water bodies of particular importance to Maori through the water bodies of national importance process, any new tools developed for the sustainable management of water should provide for Maori cultural values to be incorporated in water management decisions. Although Maori cultural values are not to be included as a specific project within the water bodies of national importance project, the relationship between Maori and water should be identified as nationally important.

3.10 Next steps

A discussion document will be developed for public release. The discussion document will describe progress with the potential water bodies of national importance sub-projects. The discussion document will also include the policy options for water quality and water allocation and use.

Consulting on this work will provide the public with an opportunity to comment on the value of determining water bodies of national importance, the methods developed to identify potential water bodies of national importance and the initial lists. Consulting on methods and criteria may result in ideas for alternative approaches for determining national importance. It is likely that the initial lists of water bodies will change following the consultation process and the public will have been given an opportunity to play an important part in critiquing the lists.

The consultation process will generate debate and will also highlight the need for national objectives for water management. Options for managing important water bodies at the national and regional level could also emerge.

The consultation process might indicate that identifying water bodies of national importance is not a useful approach. If the initial approach is to be continued, a final list of water bodies will be determined through subsequent phases of the Water Programme of Action. A candidate list of nationally important water bodies may be presented to Cabinet with options for their appropriate management.

Work is also required to address the following:

  • resolve any inconsistencies among methods and potential lists
  • establish a process to decide how competing values will be reconciled
  • explore different mechanisms to secure the values.