Wai Manawa Whenua
HIGH COURT CASE
Ian Ruru's affidavit summarised
IN THE MATTER OF an application for declaratory judgments
BETWEEN KINGI WINIATA SMILER, WALLACE PATRICK HAUMAHA, ALAN PAREKURA TOROHINA HARONGA, ROBERT VINCENT COTTRELL, and TRACEY TANIA HOUPAPA
First applicants
AND POUAKANI CLAIMS TRUST
Second applicant
AND THE ATTORNEY-GENERAL
Respondent
Alan Haronga, Ian Ruru and Kingi Smiler: Wi Pere Trust Ahuwhenua Trophy Winners 2022 & 2023
Solicitor: Roger Drummond Gibson Sheat
Address: Level 2, 50 Customhouse Quay Wellington Central, 6011
Telephone: 04 496 9990
Counsel: M S Smith | H Z Yáng Thorndon Chambers
Address: PO Box 1530 Wellington 6140
Telephone: 04 499 6040

CASE BACKGROUND
This affidavit is presented within the context of significant High Court proceedings [click thru links for detailed info] initiated by over 60 Māori Land Trusts, collectively representing more than 150,000 landowners, against the Crown. The legal action alleges the Crown's repeated failure to uphold tikanga-based and Te Tiriti o Waitangi-guaranteed rights in the management of freshwater resources.
The claimants seek immediate action to halt water degradation, formal recognition of tikanga Māori principles and proprietary rights in freshwater, and the establishment of a fair water allocation system that enables kaitiakitanga. This case arises against a backdrop of the Crown's 2012 commitments regarding freshwater management reform, which, despite subsequent judicial findings, have not been fully implemented. The timing of these proceedings coincides with the current government's efforts to roll back the Te Mana o te Wai framework.
Ian Ruru's expert affidavit provides evidence supporting these broader legal challenges, particularly in demonstrating the decline of water body mauri and the inadequacy of current management systems in incorporating tikanga-based approaches.
Setting the Scene
"The Rangatahi of Today are the Rangatira of Tomorrow"
A 90 second video starring Ian's son Kahutia Ruru and Uncle Ray Farmer. Mauri mahi, Mauri ora.
▶️ Watch Now
SECTION 1
CONTENTS

Summary of Content
Based on extensive experience and Mauri Compass Tool assessments, this affidavit presents the following:
  • Current water management systems are described in relation to their incorporation of tikanga-based assessments and Te Tiriti o Waitangi considerations.
  • Water body mauri is described as declining, with reference to existing allocation patterns, pollution, and management, affecting Māori cultural practices.
  • The Mauri Compass is presented as a systematic, comprehensive tool for assessing cultural and spiritual water health, combining mātauranga Māori and Western scientific approaches, which provides a robust, valid, and repeatable assessment framework.
  • Whānau, hapū, and iwi contributions are identified as components for water health assessment and decision-making.
  • Intervention is noted as a factor in addressing impacts on Māori water rights and mauri across Aotearoa.
SECTION 2
INTRODUCTION

Experience Highlights:
1
25
Years of extensive post-graduate experience in marine and freshwater management.
2
300+
Marae throughout Aotearoa engaged for foundational knowledge and validation.
My full name is Ian Hector Ruru. I am an independent marine and freshwater specialist based at Wainui Beach, Gisborne, with extensive experience in tikanga-based approaches to natural resource management.
I affiliate to Ngāi Tai, Te Whakatōhea, Te Aitanga a Māhaki, Rongowhakaata, and Ngāti Porou, and my expertise in Māori cultural matters is particularly focused on wai and its relationship to tikanga Māori.
I have extensive post-graduate experience in marine and freshwater management, with particular expertise in developing and applying mātauranga Māori approaches to water assessment and management.
I am a Director of Maumahara Consultancy Services Limited, a consultancy that provides tikanga-based approaches to natural resource management, and I hold/have held several governance roles including:
I have extensive experience working with various iwi in governance and advisory capacities, including as Directorships with Ngati Porou Seafoods Limited, Ngati Porou Fisheries Limited, Te Aitanga Mahaki Asset Holding Company Limited, Te Kumukumu Limited and the Iwi Collective Partnership.
I am recognised as an expert in Māori cultural matters, particularly in relation to the assessment of mauri of marine, aquifer and freshwater water bodies, and I have developed and refined the Mauri Compass Tool, which has proven utility in legal proceedings including successful use in the Environment Court.
SECTION 3

Section Overview: Annexures
This section lists the supporting documents appended to the affidavit, including the deponent's Curriculum Vitae, previous Brief of Evidence, a relevant Environment Court decision, and a Mauri Compass Assessment report.
ANNEXURES
  1. The following documents are referred to in this affidavit and are attached as Exhibits:
  1. Exhibit A: Curriculum Vitae of Ian Hector Ruru;
  1. Exhibit B: Brief of Evidence of Ian Hector Ruru in ENV-2021-AKL-000059 dated 14 April 2022;
  1. Exhibit C: Decision of the Environment Court in Remediation (NZ) Ltd v Taranaki Regional Council [2024] NZEnvC 213; and
  1. Exhibit D: Te Rūnanga o Ngāti Mutunga Mauri Compass Assessment of the Mimitangiatua and Haehanga Rivers (2022).
SECTION 4

Section Overview: Scope of Evidence
This section outlines the specific areas of expert evidence provided, focusing on tikanga Māori, the Mauri Compass Tool, and observed water quality trends. It also confirms adherence to the Code of Conduct for Expert Witnesses.
SCOPE OF EVIDENCE AND CODE OF CONDUCT
  1. I have been asked to provide expert evidence on:
  1. the tikanga Māori framework that governs Māori relationships with water bodies;
  1. the development, methodology, and application of the Mauri Compass Tool for assessing water body mauri;
  1. findings from Mauri Compass assessments I have conducted, with particular reference to my work with Te Rūnanga o Ngāti Mutunga; and
  1. observed trends in water quality and mauri conditions since 2012.
  1. I have read and agree to abide by the Code of Conduct for Expert Witnesses set out in Schedule 4 of the High Court Rules 2016. I confirm that my evidence in this affidavit is within my areas of expertise.
SECTION 5

Section Overview: The Mauri Compass Tool
This section details the development and methodology of the Mauri Compass Tool, a comprehensive tool for assessing water body mauri by synthesizing mātauranga Māori and Western scientific approaches.
THE MAURI COMPASS TOOL: DEVELOPMENT AND METHODOLOGY
  1. I have appended as Exhibit B, the Brief of Evidence I provided as a cultural expert on behalf of Te Rūnanga o Ngāti Mutunga in the Environment Court case of Remediation (NZ) Ltd v Taranaki Regional Council [2025] NZEnvC 87, the decision of which is also appended as Exhibit C.
  1. This evidence gives a complete breakdown of how the Mauri Compass Tool works from para [14] onwards.
  1. To give an overview, the Mauri Compass is a comprehensive tool that I developed to assess the mauri of water bodies, both marine and freshwater. The​ ​tool provides a robust, valid, and repeatable assessment framework. This framework is explained at [22]-[29] of Exhibit B.
Te Ao Māori (People)
Focuses on human-water relationships and cultural practices.
Te Ao Taiao (Land)
Assesses the health of land and ecosystems surrounding water bodies.
Nga Tini a Tangaroa (Water)
Evaluates the physical and chemical conditions of the water itself.
In essence, there are three attribute categories: Te Ao Māori (People); Te Ao Taiao (Land); and Nga Tini a Tangaroa (Water).
This dashboard visually represents the framework of the Mauri Compass, illustrating how its 12 attributes are organized across the three core categories to form a holistic assessment tool for water health, integrating both cultural and scientific dimensions.
Within each category, there are four attributes (totalling 12) that measure different aspects of that category that influence mauri, including physical, chemical, biological, cultural, and spiritual dimensions of water health. For example, whether mahinga kai is protected is an attribute under the People category, whereas the diversity of the plant and animal life associated with the water body is an attribute under the Land category.
Within each attribute, there are sub-attributes. For example, under the 'mahinga kai' attribute in the Te Ao Māori category, sub-attributes include: frequency of kai gathering activities, accessibility for customary resource gathering, presence of cultural practitioners with relevant knowledge, and safety of kai harvesting practices. Under the 'biodiversity' attribute in the Ao Taiao category, sub-attributes include invertebrate species diversity, EPT taxa counts (i.e., macroinvertebrates that are sensitive to water pollution), native versus exotic plant species coverage, and presence of fish migration barriers.

Mauri Compass Scoring System (Likert Scale)
The assessment uses a Likert Scale to score each sub-attribute, which are then averaged to produce attribute scores. Reasons must be given for each score.
4-5
Good to excellent mauri health
2-3
Moderate concerns requiring attention
1
Significant degradation requiring urgent intervention
Sub-attribute scores are averaged to create overall attribute scores, which are then aggregated across the three categories to provide an overall mauri assessment.
The assessment utilises a Likert Scale methodology to score each sub attribute, which are then averaged out to produce scores for each attribute. Reasons must be given for each score. This allows for quantitative analysis while maintaining the integrity of qualitative cultural assessments. Sub-attributes are scored out of 5. Scores of 4-5 indicate good to excellent mauri health, scores of 2-3 indicate moderate concerns requiring attention, and scores of 1 indicate significant degradation requiring urgent intervention. Sub-attribute scores are averaged to create overall attribute scores, which are then aggregated across the three categories to provide an overall mauri assessment.
This tool represents a synthesis of mātauranga Māori and western scientific approaches, operating as distinct bodies of knowledge that also function collaboratively to provide a holistic assessment of water health.
The foundational principles of the Mauri Compass are based on the whakataukī:
Toitū te marae o Tane
Toitū te marae o Tangaroa
Toitū te Tangata
Protect and strengthen the realms of the land
Protect and strengthen the realms of the sea
And only then will the people thrive
The Mauri Compass was infused with the mātauranga of my father, Potatutatu Bill Ruru, and was imparted to me as we taught qualifications in aquaculture and customary fishing at over 300 marae throughout Aotearoa. This extensive engagement with Māori communities across the country provided the foundational knowledge and validation for the tool's development.
The tool was further refined through collaboration with Te Rūnanga o Tūranganui-a-Kiwa and the Gisborne District Council, specifically in response to a Resource Management Act 1991 wastewater consent condition requiring improvement of "the water quality and mauri of Tūranganui-a-Kiwa."
This collaborative process involved input from both mātauranga Māori experts and western science experts, demonstrating the tool's capacity to integrate different knowledge systems.
The Mauri Compass operates on the principle that scientific measures alone may not fully define the wellbeing of waterways. The involvement of tangata whenua is considered in any assessment of water health, as water bodies are understood within tikanga Māori not merely as physical resources, but as ancestors and taonga with their own mauri.
The Mauri Compass Tool has demonstrated its utility and credibility in legal proceedings, including successful use in the Environment Court. An example decision is at Exhibit C.
This legal recognition reflects the tool's robust methodology and its capacity to provide evidence that bridges mātauranga Māori and western scientific approaches in a way that courts can understand and rely upon.
SECTION 6

Section Overview: Tikanga Māori and Water Rights
This section discusses tikanga Māori as a framework for Māori relationships with water, outlining principles such as whakapapa, rangatiratanga, and kaitiakitanga, and their interaction with water resource management and proprietary rights.
TIKANGA MĀORI AND WATER RIGHTS
  1. From my extensive experience working with iwi and hapū across Aotearoa, I can attest that tikanga Māori establishes fundamental principles governing the relationship between Māori and water bodies. These principles are not merely cultural preferences but represent a comprehensive legal and governance framework that has operated continuously since time immemorial.
  1. The core tikanga principles relevant to water management include whakapapa (genealogical connections), rangatiratanga (authority and self-determination), and kaitiakitanga (guardianship responsibilities). These principles define both rights and obligations that are inseparable from Māori identity and wellbeing.
Whakapapa
Genealogical connections between Māori and water bodies, recognizing them as ancestors.
Rangatiratanga
Authority and self-determination over ancestral waters, including decision-making considerations.
Kaitiakitanga
Active guardianship responsibilities to maintain and enhance the mauri of water bodies for future generations.
  1. Whakapapa establishes the genealogical connections between Māori and water bodies, recognising that rivers, lakes, and coastal waters are ancestors from whom Māori descend. This represents an understanding of kinship relationships that create ongoing responsibilities and rights. Through whakapapa, specific hapū and iwi have particular relationships with specific water bodies within their rohe (territories).
  1. Rangatiratanga encompasses the authority and responsibility of Māori to exercise self-determination over their ancestral waters. This includes the consideration of decisions about the use, protection, and allocation of water resources within their rohe. Rangatiratanga represents decision-making authority as guaranteed under Article II of Te Tiriti o Waitangi.
  1. Kaitiakitanga represents the active guardianship responsibilities that Māori hold toward water bodies. This encompasses both protective and management functions, requiring Māori to ensure that the mauri of water bodies is maintained and enhanced for future generations. Kaitiakitanga creates obligations to monitor, protect, and restore water health, and also rights to access and utilise water resources in sustainable ways.
  1. These tikanga principles establish what I understand to be proprietary rights in water that include both protective and utilisation dimensions.The right to protect the mauri of water bodies necessarily includes the right to prevent activities that would affect that mauri, while the right to maintain cultural and economic relationships with water includes rights to reasonable access and use.
  1. The interconnected nature of these tikanga principles means that any interference with Māori water rights affects the system of relationships and responsibilities. When water quality declines or when Māori are excluded from water allocation decisions, this affects not only specific rights but the tikanga framework that governs Māori relationships with the natural world.
  1. The Mauri Compass Tool serves as an indicator of tikanga framework integrity. When tikanga principles are described as affected, this is systematically reflected in Mauri Compass assessments across all three categories. For example:
Te Ao Māori (People) Category:
When rangatiratanga is undermined, the “mahinga kai protection” and “meaningful participation” attributes score poorly.
When whakapapa connections are severed, cultural practice attributes decline.
Te Ao Taiao (Land) Category:
When kaitiakitanga is prevented, ecosystem health attributes deteriorate because holistic guardianship cannot be exercised.
Nga Tini a Tangaroa (Water) Category:
When tikanga principles are ignored in allocation decisions, water quality attributes decline due to over-allocation without considering mauri.
The tool therefore measures not only water body health but also the extent to which tikanga-based relationships and responsibilities are being maintained and respected. Low mauri scores indicate that tikanga principles are not being upheld, and conversely the undermining of tikanga principles result in low mauri scores.
SECTION 7

Section Overview: Work with Te Runanga o Ngāti Mutunga
This section details the collaborative work with Te Rūnanga o Ngāti Mutunga, including the application of the Mauri Compass Tool to assess waterways within their rohe, outlining the role of whānau and hapū knowledge in these assessments.
A PRIVILEGE TO WORK WITH TE RŪNANGA O NGĀTI MUTUNGA
My whanau and I have had the privilege of working closely with Te Rūnanga o Ngāti Mutunga in applying the Mauri Compass Tool to assess the health and wellbeing of waterways within their rohe. This collaboration has resulted in comprehensive assessments that demonstrate both the practical application of the tool and the critical importance of whānau and hapū knowledge in water management.
I have assisted Te Rūnanga o Ngāti Mutunga in preparing two significant Mauri Compass reports. The first assessed the Mimitangatua and Urenui awa (rivers), while the second focused on the Haehanga and Mimitangiatua waterways. These assessments were conducted with the active participation and guidance of local kaumātua, kuia, and whānau members whose knowledge and observations were essential to the integrity of the assessments.
The latter report produced on the Mimitangiatua and Haehaenga awa is appended as Exhibit D, which provides an example of how the Mauri Compass Tool is applied and an assessment using the tool is undertaken.
The whānau contributions included detailed knowledge of:
  1. Historical water quality and the abundance of mahinga kai (food gathering) species.
  1. Traditional practices and ceremonies associated with specific water bodies.
  1. Observed changes in water health over recent decades.
  1. Specific locations of cultural significance and their current condition.
  1. Traditional ecological knowledge about seasonal patterns and natural cycles.
  1. The impacts of various land use activities on water quality and cultural practices.
These approaches are highlighted in the reports​,​ which reflect the fundamental principle that meaningful assessment of water health from a tikanga Māori perspective requires the active participation of tangata whenua. The expertise of whānau members, particularly kaumātua and kuia who have observed these waterways over many decades, provides irreplaceable knowledge that cannot be obtained through scientific instruments alone.
The Mauri Compass assessments conducted with Te Rūnanga o Ngāti Mutunga reported concerns about the health of waterways within their rohe. Mahinga kai attributes scored poorly due to limited safe access for traditional food gathering. Taonga species attributes, particularly those relating to tuna (eels), recorded low scores reflecting reduced abundance and health. Water chemistry attributes showed elevated nutrient levels and bacterial contamination. These low scores across multiple attributes indicated mauri conditions that affected Ngāti Mutunga's ability to exercise traditional practices and fulfill kaitiakitanga responsibilities in relation to these waterways.
These findings were consistent with broader patterns I have observed in my work across Aotearoa, where the cumulative impacts of land use intensification, and inadequate waste management, have resulted in widespread degradation of water quality and mauri.
SECTION 8

Section Overview: Water Resources Description
This section details observed changes in water quality and mauri across Aotearoa since 2012, presenting specific data, such as the reported reduction in the Waipaoa River eel population, and comparing Mauri Compass assessments of different rivers to illustrate environmental conditions.
THE DETERIORATING STATE OF WATER RESOURCES
I understand that in 2012, the Crown made commitments regarding freshwater management reform and recognition of Māori rights and interests. My assessments provide data on water body conditions and mauri states during the period following these commitments. Mauri Compass assessments I have conducted across multiple regions consistently demonstrate that water quality has declined significantly from historical baselines.
Based on my assessments across multiple regions, attributes that consistently record low scores include: mahinga kai accessibility and safety (often due to water quality concerns), taonga species abundance and health (particularly native fish species), water chemistry parameters (elevated nutrients and bacterial indicators), and catchment health indicators (relating to land use impacts and riparian protection). These patterns indicate challenges in maintaining optimal mauri conditions across different water body types and geographic regions. I am able to comment on trends since 2012, which is the focus period for this case. My Mauri Compass assessments and research provide data on water quality and mauri conditions across multiple regions during this period.
My research on the Waipaoa River, Gisborne includes comparative eel population surveys conducted in 2008 and 2018. The 2008 survey recorded 353 endemic longfin eels, while the 2018 survey recorded 79 endemic longfin eels. This represents a 78% reduction in the surveyed population over the ten-year period.

WAIPAOA RIVER EEL POPULATION: OBSERVATIONS
Between 2008 and 2018, the longfin eel population in the Waipaoa River saw a CRITICAL DECLINE.
2008 Survey
353 Endemic Longfin Eels
2018 Survey
79 Endemic Longfin Eels
The longfin tuna (Anguilla dieffenbachii) holds cultural significance within tikanga Māori as a taonga species and indicator of water body mauri. Longfin eels function as an indicator for the mauri of ancestral rivers, with their presence and abundance traditionally indicating water systems. These species have served as a food source for Māori communities for generations, forming a component of mahinga kai practices.
The lifecycle of longfin eels, which can span decades and involves migration between freshwater and marine environments, makes them sensitive to cumulative environmental changes across entire catchment systems. Their population status therefore provides an indicator of broader ecosystem health and the capacity of water bodies to sustain traditional Māori practices.
The documented decline in longfin eel populations represents an ecological disaster and a severe reduction in the availability of traditional food sources, as well as a significant impact on the cultural and spiritual dimensions of water body mauri as assessed through the Mauri Compass framework.
Ngāti Mutunga assessments of the Mimitangiatua and Haehanga Rivers
The Ngāti Mutunga assessments of the Mimitangiatua and Haehanga Rivers, conducted using the Mauri Compass methodology, recorded different mauri scores between the two waterways.
River Assessment Comparison: Mimitangiatua vs. Haehanga
The Haehanga River's lower mauri scores compared to the Mimitangiatua River are attributed to contamination impacts from the Remediation (NZ) Ltd site. Testing carried out by Taranaki Regional Council documented contamination that provided data regarding Ngāti Mutunga's concerns about the site's impacts on their ancestral waterway. This contamination affected multiple Mauri Compass attributes, including mahinga kai accessibility (due to conditions for traditional food gathering), taonga species abundance (through impacts on eel and other native species health), and water chemistry parameters (through measurable pollutant levels).
The comparative assessment demonstrates the Mauri Compass Tool's capacity to detect and quantify environmental conditions, showing how industrial contamination affects physical water quality and the tikanga framework governing Māori relationships with ancestral waters.
Additional assessments conducted between 2015 and 2022 across various regions document measured conditions of water bodies and their mauri during the post-2012 period. The data shows variations in water body health and identifies factors that influence mauri across different catchments and geographic areas. These assessments provide baseline data for understanding water body conditions and mauri states during this timeframe.
Timeline of Assessments and Trends
2012
Crown commitments on freshwater management and Māori rights.
2008-2018
Eel population surveys in munted Waipaoa River (CRITICAL DECLINE observed).
2006-2025
Period of additional Mauri Compass assessments across various regions.
Present
Ongoing conditions in water quality and mauri measured.
SECTION 9

Section Overview: Conclusion
This section synthesizes the affidavit's findings, describing ongoing conditions in water quality and mauri, and provides technical conclusions on the documented failure of current management systems to incorporate tikanga-based approaches, noting the need for remedial action.
CONCLUSION
  1. Based on my qualifications, extensive experience, and the work I have undertaken using the Mauri Compass Tool across multiple regions, the data indicates ongoing conditions in water quality maintenance and rights recognition. The assessments document that delayed intervention in water management approaches increases the complexity of future remediation while continuing to adversely affect Māori communities’ capacity to maintain cultural practices and responsibilities. The interconnected nature of water systems means that conditions in one part of a catchment may affect the entire system. Similarly, water rights recognition approaches in one context may affect the broader framework of tikanga-based water management throughout Aotearoa. Based on my assessments, I can provide the following technical findings:
  1. Current water allocation and management systems fail to adequately incorporate tikanga-based assessment methods or Tiriti considerations.
  1. The mauri of water bodies documented in my assessments shows significant decline due to allocation patterns, pollution, and management approaches, with severe consequences for Māori communities’ capacity to exercise traditional practices.
  1. The Mauri Compass is one tool that provides a systematic, comprehensive methodology for assessing cultural and spiritual dimensions of water health that are critically relevant to understanding impacts of water management decisions on Māori communities.
  1. Whānau, hapū, and iwi contributions are essential components of water health assessment and must be considered in water management decisions.
  1. The data indicates that establishing water allocation systems that incorporate Māori assessment methods would address documented challenges before further degradation occurs to water resources and community capacity. In my opinion, the Crown's current approach to water management is inconsistent with its obligations under Te Tiriti o Waitangi and tikanga Māori, and that immediate remedial action is required to address further impacts on Māori water rights and the mauri of water bodies throughout Aotearoa.
"Immediate remedial action is required to address further impacts on Māori water rights and the mauri of water bodies throughout Aotearoa."
Sworn/affirmed Ian Hector Ruru
Supporting Videos
Additional Resources for Understanding the Case
Ngati Mutunga Mauri Compass Training
A practical demonstration of the Mauri Compass methodology being applied by Ngati Mutunga, showing how this tikanga-based assessment tool is used to evaluate waterway health and environmental impacts.
Ngati Manawa & Te Wai Maori Trust
Community-led environmental monitoring and restoration work, demonstrating collaborative approaches to waterway protection and cultural responsibility.
Mauri Compass with Atihau Whanganui
Field application of the Mauri Compass methodology by Atihau Whanganui, demonstrating hands-on assessment of waterway health and environmental monitoring in practice.
Tawhirikura Mauri Compass Wananga
Educational wananga (learning gathering) demonstrating the Mauri Compass methodology, showing community-based knowledge sharing and collaborative environmental assessment practices.
These videos provide supplementary information to support the findings, offering visual and narrative context to the scientific and cultural aspects of kaitiakitanga in action in New Zealand.