Protecting natural form and character, and river extent
It’s time to make room for rivers and ensure freshwater ecosystems are as natural as possible!
Our NPS-FM position in a nutshell
Preserving the natural character of wetlands, lakes and rivers and their margins, and coastal (receiving) environments is a matter of national importance under section 6 of the RMA. Protecting river extent and values, and habitat – both parts of natural character – is also directed under the NPS-FM.
Because of the crossover between natural form and character, river extent, and physical habitat (a component of ecosystem health), and its status as a matter of national importance, natural form and character should be identified as a value for all water bodies in your region.
Failing to protect river extent and natural form and character could result in the degradation of wild and scenic rivers, loss of riparian wetlands and other habitat for birds, fish, and insects, and reduce a rivers ability to safely contain floodwaters. Loss of extent and form reduces Te Mana o te Wai and mahinga kai and takes away opportunities and places for local people and visitors to connect with water. Current river management work such as gravel extraction, river channelisation, and damming has artificially constrained rivers throughout Aotearoa New Zealand and degraded their extent and form, thereby destroying habitat and natural character.
Protecting river (and floodplain) extent should be a priority in your regional plan. Policies that support the use of nature-based solutions, such as ‘Making Room for Rivers’, is a great way to ensure your plan provides for these new approaches that can restore ecosystems and build resilience footnote 1.
You will need to measure and monitor the extent, form and character, and habitat of rivers in your region, and set target attribute states for these. The Natural Character Index (NCI) and Habitat Quality Index (HQI) are two readily available and well-researched tools that can be used to measure changes in river extent, natural form and character, and habitat. They can also be used to set target attribute states.
To effectively implement the NPS-FM and provide for natural form and character and river extent you will need to have a good understanding of what it is and take a new approach to river management.
Footnotes
Ministry for the Environment. (2022). Chapter 4: Working with Nature. In: Te hau mārohi ki anamata. Towards a productive, sustainable and inclusive economy: Aotearoa New Zealand’s First Emissions Reduction Plan.
So, what is natural form and character and river extent?
‘Natural form and character’ is not the same as ‘landscape values’ or ‘naturalness’, although it may have some overlapping components with those measures footnote 2. Exceptional, natural, or iconic aesthetic features are some qualities that natural form and character provide for, but they are not the only components of ‘natural form and character’. ‘River extent’ encompasses all land that the river needs to express its natural processes.
You need to understand basic river geomorphology and its connection to physical habitat to implement the NPS-FM. We have unpacked the intricacies of natural form and character, habitat, and river extent below.
Footnotes
2. For example, the NPS-FM describes natural form and character as “the FMU or part of the FMU has particular natural qualities that people value.” It states that “natural qualities may include exceptional, natural, or iconic aesthetic features” such as the “colour” and “clarity” of the water but also includes things like “biophysical, ecological, geological, geomorphological and morphological aspects” and “the natural location of a water body and course of a river”, among other things.
What is ‘natural form and character’ and why is it so important?
The ‘natural form and character’ of a river or stream is largely defined by the overall river form, together with the ‘mosaic’ of features within the river (such as riffles, runs, pools, backwaters, and bars), as illustrated in Figure 1. When assessing a rivers natural character and behaviour, you will need to consider where the rivers reach sits within its catchment.
Features such as riffles, runs, and pools provide valuable habitat for native riverine species, including invertebrates, fish, and birds throughout different parts of their life-cycle. Any loss or significant change to the mosaic of these features will change the ‘natural form and character’ of the river and disrupt the ‘habitat’ component of ecosystem health. This can limit habitat availability for both indigenous freshwater species and introduced species such as trout and salmon.
Figure 1 Riffle, run, and pool habitats. These features provide habitat for invertebrates, fish and birds, and in combination contribute to the natural character of a river (from Clapcott et al, 2011)
These features, when combined with larger-scale planform of a river (such as whether it is straight or sinuous) and its connection to a floodplain, as well as flow regimes and sediment supply, determine a river’s unique form. This is what makes rivers ‘meandering’ or ‘braided’ (Figure 2).
Figure 2 showing continuum of alluvial channel types (Death et al 2015)
Features also include things like the amount of in-stream cover (like wood/logs and rocks for species to hide under), riverbed composition (e.g., gravels, cobbles, and boulders), fine sediment cover, riparian vegetation, and shading (such as overhanging banks and trees). These characteristics vary by catchment and are influenced by factors such as rainfall and runoff, geology, land cover (e.g., vegetation cover and type), gradient, erosion rates, and valley-floor confinement. The large-scale form and the smaller-scale features of a river are inherently interlinked, with changes to one often affecting the other.
Rivers and streams in your region will make frequent, subtle adjustments to their form all the time (such as eroding banks or shifting gravels) as they are effectively living, moving entities. Unfortunately, policies on river management have not accommodated this and have instead considered rivers to be ‘fixed’ landforms. You may need to reflect on how rivers are currently managed and reframe your thinking to include what they need to express their ‘living personalities’.
While rivers will generally remain in a stable form overall, they will need to move over time, and your policy needs to accommodate this. Rivers and streams need to be allowed to geomorphologically adjust without constraint from traditional river management measures (such as channelisation and gravel extraction). This is critical to ensure they can ‘absorb’ the energy of floods, especially as the climate changes. This is also beneficial from cultural, social, ecological, and economic perspectives.
There are substantial opportunities to improve river management through your plans to restore natural form and character, including:
‘making room for rivers’ to better handle large flows (and avoid excessive flooding of developed areas);
understanding the flux/ movement of riverbed substrate. A quantified gravel budget is necessary to understand whether gravel extraction is appropriate, sustainable, or likely to result in damage to the river corridor. Bathymetric LiDAR is the most appropriate tool to acquire information of sufficient resolution and accuracy, and at an appropriate scale, to generate meaningful gravel budgets;
promoting and allowing for riparian restoration (and measuring it, consistent with the physical habitat attribute) and connection;
providing for more natural floodplain connections, riparian wetlands, estuaries, mangroves, and ki uta ki tai integrated management; and
importantly providing habitat for species such as trout, salmon, and indigenous freshwater species to live and reproduce throughout their natural life-cycle.
What is ‘river extent’ and why is it so important?
River extent describes the boundaries of a river's presence in the landscape. While this can be difficult to determine, it includes at least the areas a river directly influences and to its full extent, the critical water body components it interacts with, such as riparian margins, flood plains, groundwater, and wetlands. If the natural form and character of a river is like the full expression of its personality, think of river extent as the physical exterior of a human body which contains all the components as its vital organs. It encompasses not only the length of a river or reach, but also the lateral spread and movement of the river and associated features (such as its bed, tributaries, and floodplains). Remember the interconnected nature of river systems, like our body’s system, need each component cared for to function properly as a whole.
At the landscape scale, river extent is generally dynamic, changing over time due to factors such as seasonal variations in water flow, erosion and sedimentation, human activities, and climate-related changes. Large scale constraints to river extent (such as stopbanks, channelisation, and damming) will disrupt these geomorphological processes. These modifications can disconnect rivers from their floodplains, which can exacerbate flood hazards. For example, stopbanks can be useful but may create a false sense of security that it is safe to build properties, businesses, and create communities on flood plains and right up to the river’s edge – which then suffer more damaging flooding if the stopbanks are breached (see Figure 3).
As the planet warms, more areas will become susceptible to episodic flooding through more intense and frequent rain events. The series of devastating floods over the last few years is a graphic illustration that the sole use of traditional river management to constrain river extent is no longer an acceptable solution to respond to climate change and mitigate flood risk.
At a smaller scale, modifying water bodies such as piping streams or installing culverts as part of land development not only reduces stream extent but can completely remove fish passage to habitat in reaches beyond that structure (for example, when culverts become perched footnote 3. Losses in river and stream extent significantly affects the ecosystem health of water bodies, and channelisation with pipes and culverts often limits flood capacity and removes vital habitat for species.
Footnotes:
3. Perched culverts are caused when they are installed on top of the waterway bed and prevent bed materials from naturally moving downstream. Material then builds them up above the waterway bed, creating a waterfall between the culvert structure and the downstream waterway, so fish cannot move upstream.
Figure 3 Illustration of narrow and wider flood bank protection (Forest & Bird, 2022)
The NPS-FM directive
For every water body, section 6(a) of the RMA directs you to:
“recognise and provide for… the preservation of the natural character of… wetlands, and lakes and rivers and their margins, and the protection of them from inappropriate subdivision, use, and development”.
This directive is built on by the NPS-FM, which outlines that natural form and character is an inclusive term and includes biological, visual, and physical characteristics of a given water body. It includes how well the river allows for fish passage. It also supports the quality of habitat of indigenous freshwater species, and trout and salmon, which is a component of ecosystem health.
In Appendix 1A of the NPS-FM, habitat is described within the ecosystem health value as:
‘The physical form, structure, and extent of the water body, its bed, banks and margins; its riparian vegetation; and its connections to the floodplain and to groundwater’.
Natural form and character overlaps significantly with habitat. You must provide for ecosystem health, including habitat, as a compulsory value for every water body.
While it is not compulsory to include natural form and character as a value in all FMUs, because of the inherent link between natural form and character and habitat (as a component of ecosystem health) and the requirement to preserve natural character in s6(1), it should be identified as a value across your region. The degree to which natural form and character values apply in your FMUs will vary depending on each water body. You should set environmental outcomes natural form and character. Every environmental outcome will become an objective in your regional plan.
Because natural form and character is linked to the health of a waterbody, a minimum level of ‘geomorphic health’ should be provided for, before providing for people’s health needs and lastly, for the social, cultural, and economic well-being of communities.
You will need to set Target Attribute States (TASs) to meet environmental outcomes for the natural form and character of water bodies. Appendix 2A or 2B does not include any compulsory attributes for natural form and character, however the NPS-FM does identify some components that may be useful such as water colour and clarity, the presence of culturally significant species, and water body’s biophysical, ecological, geological, geomorphological, and morphological functions and the dominance of indigenous flora and fauna. Suspended and deposited sediment are also useful attributes for natural form and character (and habitat) in the NPS-FM.
While you may feel that natural form and character will be sufficiently covered by monitoring and managing other attributes (such as water quality, quantity, and biotic assemblages footnote 4 ) and managing rivers through setting minimum flows/levels, allocation amounts, and policies/rules for example structures in water bodies, it will not sufficiently capture form and character. The NPS-FM asks you to consider the range of matters relating to the water bodies biological, visual, and physical characteristics (such as extent and physical habitat conditions) that the community value. To achieve this, you will need a measure of the geomorphological condition of your rivers.
Monitoring natural form and character and river extent will help to ensure further loss of river extent and values is avoided.
Clause 3.24 (Rivers) of the NPS-FM directs you to include policy provisions in your regional plan that avoid the loss of any further river extent and values (unless activities meet certain criteria). You will need to find ways to measure natural form and character at a regional ‘State of the Environment’ level as well as measuring an activities’ individual effect on river extent and ensure there is no further loss. To do this you must monitor river conditions to determine whether your policies, rules and methods are achieving Clause 3.24.
Mana whenua may identify natural form and character as a component of Te Mana o te Wai, and part of the fundamental health and wellbeing of a water body. In those cases, attributes and limits relating to extent and physical habitat conditions may be useful starting points in the cultural context, subject to the views of mana whenua. Quantitative measures could be integrated with or sit parallel to cultural indicators.
Footnotes
4. Death, Fuller, & Death, in prep.; Harding et al., 2009; Maddock, 1999; Raven, Fox, Everard, Holmes, & Dawson, 1997.
What do we want to see?
River extent is a fundamental geomorphological component of a water body’s natural form and character. Rivers need space to express their unique personality and support the ecosystems they are intimately connected to. Importantly, naturally functioning river systems support climate change adaptation and can mitigate flooding. Loss of extent and form can even threaten rivers’ ability to recharge aquifers and has the potential to intensify the impact of flood events and worsen flood damage.
Activities such as channelisation, damming and stopbanks disconnect rivers from floodplains and groundwater, simplify their form, and remove vegetation from riparian margins. Ultimately, restricting rivers’ natural behaviours reduces their functionality and ecosystem health, reduces their recreation and amenity value, and has the potential to intensify the impact of flood events and worsen flood damage.
The three components of “river extent”, “natural form and character”, and “habitat” (as a component of ecosystem health) cannot be separated from one another. The connection back to activities on land (such as erosion and land cover) means it is critical to manage these activities, and to monitor what is happening to river form so you can understand these linkages.
We want to see:
Natural form and character identified as a value for every water body
It is important for river management to maintain and improve the physical characteristics of river geomorphology to preserve water quality and quantity footnote 5. It helps to protect ecosystem health while also supporting modern flood management efforts, reducing the effects of climate change, and providing social and cultural benefits such as enhanced recreation and mahinga kai opportunities footnote 6.
Provisions in your plans that support a move away from traditional 'command and control’ ethos to river ‘management’ and flood protection that ‘let the river be a river’ ethos and let them do what rivers do.
We want to see policies that enable natural river behaviour by prioritising nature-based solutions such as ‘making room for rivers’ and erodible river corridors. We want to see the restoration of what have been referred to as our ‘zombie rivers’ footnote 7. This is a key way you can give effect to NPS-FM requirements for natural form and character (and habitat as a component of ecosystem health).
Action Plans that set out how character will be maintained and how rivers will be enabled to function more naturally
This includes how flood management plans might be amended and gravel movement through catchments researched.
Plans could include steps to reconnect rivers with their flood plains and provide large enough riparian strips along rivers to allow natural processes, such as erosion, to occur as appropriate. Restoration projects should increase the connectivity of rivers to their banks and floodplains to provide greater floodwater storage in floodplains. This will help to address increasing flood severity under climate change, while also enhancing freshwater ecosystem health footnote 8.
Rules that prohibit the piping of streams, and provisions that encourage the ‘daylighting’ of steams
This is where piped streams are opened up so that water is exposed to natural light. We know that projects can be designed to better retain and enhance water bodies while meeting development needs.
Activities in the beds and on the margins of rivers regulated carefully
Activities such as gravel extraction, flood protection works, river channelisation, and damming, as well as riparian land cover changes and encroachment must be well managed to avoid or minimise effects on natural form and character, river extent, and habitat.
Provisions on natural form and character and river extent that support the other compulsory values of ecosystem health, mahinga kai, human contact, and threatened species
We want to see you work with your communities and tangata whenua to identify the personalities and geomorphic stories of each water body so you can protect and plan for its natural behaviours.
The use of geomorphological measurement tools in your regional plan to measure natural form and character and river extent
We suggest the Natural Character Index (NCI) and the Habitat Quality Index (HQI), which are variations of a readily available and well-researched tool that can help with this (more on this below). They can be used as attributes and to set limits to protect natural form and character and river extent. Large-scale geomorphological variables relating to river extent (such as active channel and floodplain width, braiding, and/or sinuosity) should be identified in your regional plan and monitored. At a finer scale, features such as riffles, runs, and pools should be monitored when activities that might impact them are undertaken.
You might have baseline information or existing monitoring programs using tools like Stream Ecological Valuation, Rapid Habitat Assessment, Stream Habitat Assessment Protocols, or River Styles. These, along with other information you have on river character, habitat, and extent could be useful to inform Target Attribute States and baselines; and to design provisions that will work for the rivers in your region.
Objectives and targets for natural form and character and river extent in your regional plan to supplement monitoring
This should include Target Attribute States that capture the geomorphological elements of natural form and character, habitat, and river extent. Footnote 9.
Objectives or targets would be relatively easy to include and to monitor progress against (e.g., LINZ aerial imagery could be used, along with manual or automated GIS processes). You can introduce limits on change (i.e., degradation) in river extent and habitat quality in a plan change using geomorphological assessment tools like the NCI/HQI.
Your regional plan prevents the net loss of habitat or river extent
This includes loss of active channel length and sinuosity and narrowing of the flood corridor. Where loss does occur as the result of an activity, the loss of river extent or habitat should be quantified so that mitigation measures recognise the quanta and offset this loss by restoring character in a river in another suitable location, and to a similar or improved condition.
Geomorphological assessment tools are critical to assist with this. There are two tests for altering the physical nature of a river or stream. For example, flood engineering to prevent damage to people and their infrastructure, or streams require piping as part of a development. One test is where there is a functiona need, as defined in the NPS-FM. The other test is through applying the effects management hierarchy. Make sure you understand each test and how to apply it.
Plans that consider the effects of use and land development on geomorphology (natural form and character) on a whole-of-catchment basis.
We want to see you engage with groups, including Fish & Game, Forest & Bird, and Choose Clean Water, local communities, and tangata whenua to develop river stories and understand the history and potential future of the geomorphology of your rivers.
Plan changes provide you with an excellent opportunity to work with flood management / river engineers, tangata whenua, and communities to put in place provisions that will enable understanding of river history (such as through action plans) and achievement of shared long-term visions. Meaningful and strategic engagement on river geomorphology (including flooding) also allows a co-ordinated approach to urban growth and will help with community flood risk prevention and awareness.
Footnotes
5. Statement of Evidence of Professor Russell George Death on behalf of Wellington Bay Fish and Game. Geomorphology and freshwater ecology 21 Aug 2017.
6. Statement of Evidence of Professor Russell George Death on behalf of Wellington Bay Fish and Game. Geomorphology and freshwater ecology 21 Aug 2017.
7. Brierley et al (2022) Reanimating the strangled rivers of Aotearoa New Zealand. WIREs Water 10:e1624. https://doi.org/10.1002/wat2.1624
8. Abell et al (2022) Large floodplain river restoration in New Zealand: synthesis and critical evaluation to inform restoration planning and research. Regional Environmental Change, 23:18.
9. For example, the current average width of a section of river being identified as 100m in a regional plan, with an accompanying objective set to restore the width to a historic level of 120m. Another example would be that a river has been channelised into a straight ‘drain’, with a resultant sinuosity value of 1.0, but the objective may be to restore the sinuosity to a level of 1.5.
How should the NPS-FM be implemented?
Take a new approach to river management
We need to shift our thinking in river management and respect each river’s right to be diverse and variable.
River management practices must recognise and implement methods that work with rivers’ natural processes. A river’s ability to express its unique form is dependent on local decision makers limiting the interventions they make in these rivers. A nature-based solution that ‘makes room for rivers’ by working with them, instead of ‘making all rivers the same’ through engineering intervention or constraint, demonstrates this new approach to river management.
Recent research and best information available in river geomorphology highlights that as part of resilience‐based management practices, we will benefit if we can learn to live with the variability, complexity, and uncertainty of river systems. Constraining rivers and expecting them to be static accentuates flood risk where development is then enabled around them. Living with rivers, and allowing them to exhibit natural behaviours, is generally the cheapest and safest option for management, with significant ecological, cultural, and social outcomes.
Through good urban design, smaller streams in developed areas can also be retained in their natural form to enhance urban areas, flood capacity, and ecosystem health. Initiatives such as “making room for rivers”, “freedom space”, and ‘daylighting’ have been established in urban areas in various parts of the world. Footnote 10. These initiatives have been adopted as a more sustainable approach to living with rivers rather than trying to control or constraint them. These initiatives support the shifting habitat mosaic of river systems. They recognise the environmental benefits that come from allowing a river to flow more freely and self‐adjust within its corridor and that such measures can minimise flood risk to the public and minimise economic costs, better protecting property and infrastructure. Footnote 11.
Footnotes
10. Biron et al (2014) Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience. Environmental Management 54:1056–1073.
11. Brierley et al (2018) A geomorphic perspective on the rights of the river in Aotearoa New Zealand. River Res Applic.1–12
Prioritise nature-based solutions
Prioritise actions to protect, restore, and manage ecosystems in a way that allows them to exhibit natural processes as much as possible. Through initiatives such as Making Room for Rivers, natural form and character, river extent, habitat, and ecosystem health can be better provided for. Best available evidence also shows that nature-based solutions are generally more effective than ‘engineered’ solutions for a multitude of reasons.
Well-designed nature-based solutions that support water bodies’ natural form and character can be part of an integrated response to climate change and support biodiversity. As mentioned above, providing room for the river and restoring habitat for species (footnote 12) can also contribute to protecting communities and infrastructure from flooding and erosion, increasing resilience, carbon sequestration, and protecting biodiversity34.
Such approaches are also much more consistent with Te Ao Māori and Te Mana o te Wai in that they take a holistic view to managing rivers. Footnote 13.
For example, if you exclude stock from water bodies, protect wide (at least 10 metres) riparian margins, let rivers move in their corridors, and allow land adjacent to the river to flood (dissipating the energy of floodwaters), you will also provide for a whole range of other ecosystem benefits such as wetland restoration and carbon sequestration, increased groundwater recharge, river habitat restoration for native fish, birds and insects, mahinga kai, and more recreation opportunities for people.
Footnotes
12. Petrove, N. And McEwan. A. (2024). Habitat requirements of freshwater fish in Aotearoa New Zealand. Department of Conservation. Refer www.doc.govt.nz under Publications.
13. Ministry for the Environment (2022). Te hau mārohi ki anamata Towards a productive,sustainable and inclusive economy, Chapter 4: Working with nature. Aotearoa New Zealand’s First Emissions Reduction Plan.
Understand river form and function
To give effect to the NPS-FM in your regional plan, it is critical to understand what constitutes and defines the ‘natural form and character’ of a river. That is, you should understand (or your plan should aspire to understand) the processes forming the rivers in your region - such as sediment movement, erosion, land cover, and climate.
You should acknowledge that diversity is good. Some technical understanding of how and why rivers function as they do, and their contribution to habitat and the wider environment (such as how they might recharge groundwater in your aquifers) is essential to protecting natural form and character and river extent in your regional plan, as well as to effective integrated management. Policy direction should encourage working with natural processes, interpreting the behaviour of each river, rather than supporting over-engineered solutions to control them. This recognises that geomorphological processes (e.g., erosion and deposition), in appropriate places, at appropriate rates, are intrinsic functions of a healthy living river.
You will also need to assess and measure natural form and character, highlighting what to measure (your attributes) and what to measure against (your baseline or ‘reference’ state) in your plan. When setting targets, it will be useful to understand the trends and changes in your rivers to determine what is realistic to achieve in a given river’s management.
For example, you (i.e., your science and river management teams) should understand whether rivers sit on a degradation or recovery pathway (i.e., condition is deteriorating or improving) and understand the recovery potential of your rivers. Ask yourself, which rivers are functioning well and need to be protected to avoid future problems? Determine if it is possible for any rivers to return to a natural or ‘pristine’ state or is a semi-modified state the new norm? Can highly modified rivers be restored somewhat to a healthier condition? Understanding such questions allows outcomes to be set and measures to achieve these outcomes developed (e.g., through an Action plan).
A collective understanding within your team about the river form and character and river extent can provide a coherent platform to develop and apply proactive and precautionary catchment management plans.
Use natural form and character values to meet other NPS-FM requirements
Protecting natural character helps protects many other values. Identify natural form and character values for all water bodies in your regional plans. This will help to meet your Policy 7 and Policy 4 directives for river extent and integrated climate change responses within your freshwater management.
Recognising natural form and character also provides a strong base to support Te Mana o te Wai as the objective of the NPS-FM. For example, by maintaining natural form and character first (and allowing rivers to exhibit natural behaviours), you can provide buffers and natural resilience that reduces flood risk to people (protecting human health), while providing more variety and a greater extent of habitat for species to adapt to their changing environment (protecting ecosystem health). It provides more areas for people to make contact and recreate in water bodies (increasing the potential for people to value rivers, the more deeply connected they feel). It also supports the mental health benefits that may come from people connection to nature,
Protecting natural form and character keeps water bodies connected to their catchment context – allowing them to replenish smaller streams, wetlands, groundwater, and lake environments, thereby providing greater opportunities for vital mahinga kai areas for tangata whenua.
It really is a win, win incentive for species and people alike but most importantly - it is a win for the awa.
Maintain fish passage
Protecting natural form and character complements the inclusion of polices in your plan that ensure fish passage is maintained or improved. Many structures that impact natural form and character, such as dams and intake structures are barriers to habitat for a wide range of fish species.
Protecting natural character helps provide for fish species to pass through water bodies as they migrate between freshwater and marine habitats as part of their life cycle. Footnote 14.
Footnotes
14. NIWA. (2007). Fish screening: good practice guidelines for Canterbury. Prefpared for: Fish Screen Working Party: Environment Canterbury Fish & Game New Zealand Department of Conservation.
Use the Natural Character Index / Habitat Quality Index (NCI/HQI) to measure natural form and character and river extent
You’ll need to measure and monitor natural form and character to ensure you can maintain it, as well as to meet target attribute states you set. The Natural Character Index (NCI) and the Habitat Quality Index (HQI) (footnote 15) are variations of the same tool, used to measure and summarise characteristics of a river such as channel width, braiding, habitat, and sinuosity over time. Measurements are made against a baseline state for the same river in the past. This allow changes in the natural form and character, extent, and habitat quality to be assessed. Conclusions can then be drawn as to whether maintenance is being achieved, or mitigation may be required.
Because NCI and HQI are assessed as the ‘current’ state against a ‘baseline’ state, they are expressed as a ratio of current/baseline. For example, if the average width of a section of river is now 60m, but used to be 100m, its score would be 0.6 (because 60/100 = 0.6).
The NCI/HQI methods have the benefit of being able to be used at different spatial and temporal scales, that is, at a consent /activity level to assess reach-scale changes over several months or years, and at the plan and State of the Environment monitoring level to assess landscape-scale change over decades.
The NCI can be used to measure components of river character and extent at a landscape scale, such as channel and flood plain width, braiding, presence of vegetated and unvegetated bars, and sinuosity. It allows the character and extent of rivers to be assessed against a baseline (reference) point in the past, typically using historic aerial photography, maps, and/or LiDAR. Baseline states should ideally be from a time prior to extensive river or flood management works having been undertaken to modify river extent and course. This historical river extent can then be compared to recent data (e.g., satellite imagery, aerial photography, LiDAR) to determine the changes in geomorphological characteristics and overall extent of the river over time.
The HQI can be used to measure components of river character and habitat at a reach scale, such as riffle/run/pool sequences, sediment cover, instream wood, shading, and erosion. It allows the habitat in a section of a river to be assessed at two (or more) points in time, such as before and after an activity like gravel extraction, and then compared to reveal any changes in habitat quality. It involves the use of data collected on-the-ground, often in combination with a drone survey (though satellite imagery may also work). It can be helpful to assess the impacts of consented activities or compliance of consented activities to maintain river habitat, for example.
The NCI and HQI can be incorporated into plans by including:
Limits on changes to natural character and habitat quality (e.g., included as objectives or as a schedule to the regional plan specifying standards/limits for natural character and habitat quality for FMUs or sub-FMUs in the region). These would effectively mean activities couldn’t result in the HQI or NCI score for rivers in an FMU or part-FMU going below a certain ratio score when measured against a certain point in time.
Target Attribute States for NCI and HQI scores aimed at maintaining or restoring natural processes to support ecosystem health in freshwater bodies. For example, a lowland section of river that has been degraded against its historic condition might have an NCI score of 0.6; but a Target State could be set to restore it to a score of 0.9 against that historic condition. For hill country streams in native forest, an NCI target of 1.0 against current condition would ensure natural character is maintained.
Objectives and/or policies with the intent that the natural character, extent, and physical habitat of freshwater bodies is safeguarded such that ecosystem health is maintained or improved and limits referred to above are not exceeded.
Provisions that direct the use of the NCI/HQI in any river management works or resource consent applications with an ‘in-stream’ component or physical effect on the river geomorphology. Direction would also include that any degradation in extent, habitat quality, and/or natural character resulting from the works would need to be remediated.
Methods stating:
(a) Councils will utilise the NCI/HQI to assess past and future change in the extent, natural character and habitat quality of water bodies, to inform river management and flood protection planning and decisions (including the development of a modern approach to flood management) and safeguard extent, natural character and physical habitat in accordance with limits specified in a schedule to the regional plan.
(b) Council will report on compliance with NCI/HQI standards as part of its State of the Environment monitoring (this ensures NPS-FM Policy 14 and s3.18 and 3.24 are given effect to).
The NCI and HQI tools also:
provide a mechanism for developing flood management practices that are more accommodating of natural river processes to improve both flood management and habitat protection. Your provisions relating to the beds of rivers and natural hazards should consider how they can be written to allow for better assessment and monitoring of natural character and habitat using the NCI and HQI.
provide a way to assess the protection of the significant values of outstanding water bodies.
Footnotes
15. See more information below.
Set target attribute states
You should set Target Attribute States for natural form and character, habitat, and river extent. At a minimum, these should be set to maintain river condition and provide for ecosystem health We’ve outlined how tools like the NCI and HQI can be used to set TASs for natural form and character, river extent, and habitat above.
Your council might have some existing monitoring of potential attributes already – such as through Stream Ecological Valuation (SEV), River Habitat Assessment (RHA), Stream Habitat Assessment Protocols (SHAP), or the River Styles framework. You might be able to incorporate these as attributes, or in consent conditions. However, you should be conscious that tools like RHA tend to only assess habitat at a single site and won’t capture the same information on the form and character of a river across the same scale that the NCI would.
The NPS-FM requires you to include attributes for all values you identify for water bodies. If attributes can’t be identified or are insufficient to assess a value, you must identify alternative criteria (NPS-FM 3.10). Attributes must be specific and, where practicable, be able to be assessed in numeric terms; and baseline states should be determined. This is part of the reason why we recommend the use of the HQI and NCI – they can be measured in numeric terms; and baselines can be historic or current state (for which data at some scale in aerial imagery, satellite imagery, or maps is often available).
Once you have identified all relevant attributes to monitor natural form and character, river extent, and habitat, you should then determine if more stringent target attribute states are required to provide for the compulsory and other health and well-being values (such as identified trout and salmon habitat areas, the presence of threatened species or outstanding water bodies). It could be, for example, that a river in your region has an NCI score of 0.4 but a value of 0.6 is needed to provide for minimum ecosystem health values. This could be the target state for restoration.
Often ecosystem health will provide for other values, but where it does not, you will need to identify more rigorous target attribute states to provide for these values.
Provisions must be specific and measurable
Objectives and policies should not just restate the RMA or NPS-FM.
Objectives and policies about natural form and character need to identify a goal to maintain and enhance the natural form and character of water bodies, including their extent. They should also state that natural form and character will be managed through specific measures such as HQI and NCI, and this should be carried through to provisions relating to activities in river beds and the approach taken to managing natural hazard/flood risk from rivers.
Water bodies that have outstanding or significant or high natural form and character values should be identified, and specific maintenance and improvement goals for those water bodies developed. We expect that limits to halt further degradation of river and stream natural form and character, and habitat quality, would be included as part of the resource management framework in your regional plan.
Engage widely to deliver an integrated approach
It is important to consult those who manage or work in rivers such as flood management teams and contractors to ensure that new ways of managing rivers can be realised and collectively worked towards. Together with iwi/hapū, and the community, you should work through the National Objectives Framework (NOF) to set ecological and flood protection environmental outcomes that protect the health and well-being of water bodies and freshwater ecosystems.
This process can also be used to raise awareness of flood risk and flood pathways, and to communicate how nature-based solutions – such as making room for rivers – can improve outcomes.
How we will know the NPS-FM is being achieved.
Natural form and character will be identified as a value for every water body in your regional plan. River extent will be included as a component of natural form and character. And tools like the NCI and HQI will be used to establish target attribute states and limits for works in and around rivers and their floodplains, as well as targets for restoring river extent.
Nature-based solutions will be prioritised where appropriate and their contribution to improving biodiversity and climate change adaptation and resilience will be recognised and given additional weight. Co-benefits will be considered when making decisions on regional plans. Natural form and character will be regularly monitored and reported on.
As a result of new ways to managing rivers, they will be able to express their ‘personality’ and (re)connect to their floodplains within the wider landscape which support smaller streams and tributaries as well as wetlands, lakes, and ground water systems. The full extent of a river will contribute to a flourishing freshwater habitat that supports all species throughout various times in their life cycle. Alongside this, communities will safely co-exist in these landscapes and people will be able to appreciate and use rivers, streams, and lakes for their well-being and recreational needs as well as for mahinga kai where tangata whenua have recognised such areas.
Implementation Toolbox
The toolbox will continue to be developed as new information becomes available:
Tools: are helpful diagrams, processes, or ways to support how you should implement the NPS-FM.
Examples:provide text suggestions to help draft objectives (values and environmental outcomes), policies, and rules (limits) in your regional plans, including how monitoring could be achieved. It includes examples of how attributes and base line states, target attribute states, environmental flows and levels, and other criteria, where appropriate, can be written or presented to help achieve environmental outcomes.
Case studies: illustrate where the NPS-FM has been well applied (or not) throughout the country and provides national or international lessons to help implement the NPS-FM.
Evidence: provides relevant case law to support how the NPS-FM must be applied.
Resources: provide links to supporting literature and best information available to implement the NPS-FM.
Tools
Natural Character Index (NCI) and Habitat Quality Index (HQI)
NCI
As noted above, the NCI can be used to measure components of river character and extent at a landscape scale, such as channel and flood plain width, braiding, presence of vegetated and unvegetated bars, and sinuosity. It allows the character and extent of rivers to be assessed against a baseline (reference) point in the past, typically using historic aerial photography, maps, and/or LiDAR. Baseline states should ideally be from a time prior to extensive river or flood management works having been undertaken to modify river extent and course. This historical river extent can then be compared to recent data (e.g., satellite imagery, aerial photography, LiDAR) to determine the changes in geomorphological characteristics and overall extent of the river over time.
Some examples of the NCI being applied include:
Fuller, I. (April 2023). Natural Character Index (NCI) for Whitestone and Upukerora Rivers. Report for Environment Southland.
Fuller et. al. (2020). An index to assess the extent and success of river and floodplain restoration: Recognising dynamic response trajectories and applying a process-based approach to managing river recovery. https://doi.org/10.1002/rra.3672
Kay, T (2020). Habitat Quality Index Assessment: Rangitata River, Arundel to Ealing. Prepared for Forest & Bird | Te reo o te Taiao
HQI
The HQI can be used to measure components of river character and habitat at a reach scale, such as riffle/run/pool sequences, sediment cover, instream wood, shading, and erosion. It allows the habitat in a section of a river to be assessed at two (or more) points in time, such as before and after an activity like gravel extraction, and then compared to reveal any changes in habitat quality. It involves the use of data collected on-the-ground, often in combination with a drone survey (though satellite imagery may also work). It can be helpful to assess the impacts of consented activities or compliance of consented activities to maintain river habitat, for example.
Some examples of the HQI being applied include:
Death, R., Death, A., Jordan, C., Fuller, I. C., & Cameron, D. (n.d.a). A technique (eNCI) for assessing natural character impacts of river management activities.
Chapter 3 of Kay, T (2020). A methodology to assess river habitat quality: a thesis presented in partial fulfilment of the requirements for the degree of a Masters in Science in Ecology at Massey University, Manawatū, Aotearoa New Zealand. https://mro.massey.ac.nz/items/efa12e8a-ceee-41c1-8fa3-c52a73f89b52
McArthur, K., and Kay, T. (2022). Mangatainoka River at Mowbrays Rd. Water Quality and Ecological Report for Gravel Extraction Application by Prenters Aggregates for Kahungunu Ki Tāmaki Nui-A-Rua.
Examples
This section includes some examples of the type of wording we expect to see in provisions to protect natural form and character, river extent, and habitat; as well as examples of monitoring and reporting. We’ll keep updating it as we see more examples of good provisions. We’ve based these on what we consider the best wording we’ve seen across a range of plans and plan development processes and then improved the wording ourselves. These provisions relate to freshwater outcomes, the management of activities in river beds, and the management of natural hazards.
OBJECTIVE EXAMPLE – River function and natural hazards
The risk of, and effects on communities and property from, natural hazards (including those arising from or exacerbated by climate change) is managed by
a) Protecting and restoring the ability of rivers, lakes, and wetlands to accommodate and mitigate natural hazard impact
b) maintaining and improving the ability of modified watercourses and artificial water courses accommodate and mitigate natural hazard impact, including restoring them to a more natural state
Policy Example:
Decisions must ensure that:
1. in all areas,
a. the protection, restoration or enhancement of natural defences that protect land uses, or sites of significant biodiversity, cultural or historic heritage or geological value, from natural hazards is provided for, and
b. it is recognised that such natural defences include, but are not limited to, native forests, river corridors, floodplains, wetlands, intertidal areas, coastal vegetation, dunes and tussockland, and
c. any more than minor adverse effects of development on the ability of those natural defences to continue to mitigate risk, including risk to areas downstream, is avoided, remedied or mitigated, and
2. use of water-sensitive design, such as through rainwater harvesting devices, green roofs, site landscaping, rain gardens, wetland treatment systems, and low impact stormwater attenuation systems is required, and
3. redevelopment, or change in land use, where that would reduce the risk of adverse effects from hazards, including managed retreat by relocation or removal of existing structures or their abandonment in extreme circumstances, and designing for relocatability or recoverability from hazard events is encouraged, and
4. a precautionary approach is taken where information is uncertain, unknown or little understood.
Greater Wellington Regional Council RPS Change 1 examples:
Policy 52
When considering… hazard mitigation measures, particular regard shall be given to:
(a) the need for structural protection works or hard engineering methods;
(b) whether non-structural, soft engineering, green infrastructure, room for the river or Mātauranga Māori options provide a more appropriate or suitably innovative solution…
Policy CC.16
Climate change adaptation strategies, plans and implementation programmes – non-regulatory
Regional, city and district councils should, under the Local Government Act 2002, partner with mana whenua / tangata whenua and engage local communities in a decision-making process to develop and implement strategic climate change adaptation plans that map out management options over short, medium and long term timeframes, using a range of tools and methods including, but not limited to:
…
(f) Hazard mitigation options including soft engineering, green infrastructure or room for the river, and methods to reduce the risks from natural hazards exacerbated by climate change and sea level rise
https://www.gw.govt.nz/assets/Documents/2022/08/Proposed-RPS-Change-1-for-the-Wellington-Region.pdf
Rules (limits)
[To be developed]
Attributes and baseline states
[To be developed]
Target Attribute States
[To be developed]
Monitoring
Example of how natural form and function could be monitored and reported over time
The above sections on the HQI and NCI discuss how these tools work. However, the below figure illustrates a useful way the results can be communicated for State of the Environment reporting.
Figure 4. (from Fuller et al. 2020, DOI: 10.1002/rra.3672)
Monitoring Plans
Hawkes Bay Regional Council was granted Global Consents for Gravel Extraction in three awa (Ngaruroro, Tukituki and Tūtaekurī). This includes provision to modify river extent. Condition’s include for the consent holder to restore the sites:
“The consent holder shall ensure that the site is restored on completion of the gravel extraction operation as follows: d) All disturbed areas shall be reinstated as far as is practical to minimise the release of sediment to flowing waters and to maintain the natural character of the river system”.
The consents include a monitoring plan for gravel extraction which is a good example demonstrating how to manage and monitor this activity.
Case studies
Natural Character Index (NCI) used to assess the Whitestone and Upukerora Rivers
Historic imagery between 1953 and 2014 were used for to undertake an NCI assessment to determine the change in river characteristics of the Whitestone and Upukerora Rivers. Measures included:
“the active channel, wetted channel, unvegetated bars, lightly and densely vegetated bars. These features provide a broad overview of river geomorphology in the active channel of the Whitestone and Upukerora Rivers”.
The NCI approach assessed these features and provided a ratio of the parameters between 1953 and 2014 to provide a ‘whole river’ assessment. It also analysed channel sinuosity and braiding index which focused on discrete, morphologically coherent reaches in each river.
Text taken from Report for Environment Southland (footnote 16), the summary of changes were:
“The most significant changes in the Whitestone river corridor were a 50% reduction in active channel area and 78% reduction in the area of densely vegetated bars. The wetted channel area and length have also reduced by 34%. Midline channel length was shortened by 11%. Braiding intensity in partially braided reaches was reduced. Sinuosity in meandering reaches was also reduced. These changes indicate channel rationalisation and homogenisation within a narrowed active channel. The 2014 river no longer displayed the alternating meandering-wandering reaches of 1953, but is largely wandering throughout.
The most significant changes in the Upukerora river corridor were a 46% reduction in active channel area and 54-55% reduction in lightly vegetated and densely vegetated bars respectively. Wetted channel area has also reduced, although total and midline lengths were essentially unchanged. Upper reaches of the Upukerora remained largely unchanged, retaining a partially-braided wandering form. Braiding intensity was significantly reduced in the lower reaches, but a simplified wandering form has been retained”.
This shows how the NCI can be used as an attribute to assess the extent to which a particular value can be provided for.
In this instance, the report recommended that: ‘to recover the degree of natural character (i.e. characteristics that better reflect the geomorphology that would develop under the prevailing sediment and flow regime), it is recommended that where feasible the river be given more room to adjust and develop these characteristic forms’.
Figure 5.
Footnotes
16. Fuller, I. (April 2023). Natural Character Index (NCI) for Whitestone and Upukerora Rivers. Report for Environment Southland.
Habitat Quality Index (HQI) used to assess the Rangitata River
The Rangitata River, which has a Water Conservation Order, was identified as having experienced substantial modification to its physical conditions. Forest & Bird undertook a Habitat Quality [Natural Character] Index (HQI) assessment (footnote 17) of the river (footnote 18) to quantify any change in habitat quality from 1937 to 2016-2018.
The parameters measured were active channel width, natural and permitted floodplain width, and mid-channel bar length, which was used to calculate a braiding index. The authors who developed the tool, Pratt, Neverman, Fuller, & Death (2018) indicated 'that a decline of more than 15% in an overall score, or 40% in any single component score should be cause for concern and would indicate a potential need for mitigation activity’.
Scores for floodplain width and the overall score for active channel width in the Rangitata River resulted in quantifiable evidence to have concern for these components of natural form and character, as they indicated a significant reduction in the rivers physical conditions. Forest & Bird were able to quantify the consequence of the river modification and demonstrate the use of HQI/NCI for future river management.
Figure 6. From Forest & Bird Habitat Quality Index Assessment: Rangitata River Arundel to Earling
Waipara River in Canterbury has made room for rivers and prioristied natural character
Environment Canterbury (ECan) has a project underway that seeks to transistion the berm of rivers, including the Waipara River to more native plantings and targeted weed control. This includes removing 15km of mature trees from the riverbed such as willow, poplar and pine trees to keep the community safe, while recognising the wider environmental benefits such as habitat for threatened species and improved biodiversity. Importantly, this work assists with flood resilience, creating a more natural braided pattern, which reduces flood and erosion risk.
Figure 7. Waipara River Stockgrove Road - Drone shot before and after willow clearing
Footnotes
17. Kay, T (2020). Habitat Quality Index Assessment: Rangitata River, Arundel to Ealing. Prepared for Forest & Bird | Te reo o te taiao
18.
Evidence
[When available]
Resources
Abell, J.M., Pingram, M.A., Deniz Özkundakci, D., David B.O, Scarsbrook, M., Wilding, T., Williams, A., ·Noble, M., · Brasington, J. and · Perrie, A. (2023). Large floodplain river restoration in New Zealand: synthesis and critical evaluation to inform restoration planning and research. Regional Environmental Change 23:18. https://doi.org/10.1007/s10113-022-01995-z
Brierley et al (2022) Reanimating the strangled rivers of Aotearoa New Zealand. WIREs Water 10:e1624. https://doi.org/10.1002/wat2.1624
Brierley et al (2018) A geomorphic perspective on the rights of the river in Aotearoa New Zealand. River Res Applic.1–12
Biron, P.M, Buffin-Be´langer, T., Larocque, M., Chone, G., Cloutier, C., Ouellet, M., Demers, S., Olsen, T., Desjarlais, C. and Eyquem, J. (2014) Freedom Space for Rivers: A Sustainable Management Approach to Enhance River Resilience. Environmental Management 54:1056–1073
DOI 10.1007/s00267-014-0366-z
Death et al (2015) Resetting the river template: the potential for climate-related extreme floods to transform river geomorphology and ecology. Freshwater Biology 60, 2477–2496.
Death, R. G., Fuller, I. C., & Death, A. M. (n.d.a., in prep.) A technique to assess river habitat change – the missing dimension for water resource management.
Death, R., Death, A., Jordan, C., Fuller, I. C., & Cameron, D. (n.d.a). A technique (eNCI) for assessing natural character impacts of river management activities.
Fuller, I. (April 2023). Natural Character Index (NCI) for Whitestone and Upukerora Rivers. Report for Environment Southland.
Fuller, I. C., Death, R. G., Garcia, J. H., Trenc, N., Pratt, R., Pitiot, C., Matoš, B., Ollero, A., Neverman, A., Death, A. (2020). An index to assess the extent and success of river and floodplain restoration: Recognising dynamic response trajectories and applying a process-based approach to managing river recovery. River Research and Applications. https://www.bib.irb.hr/1073145/download/1073145.Fuller_et_al_2020.pdf
Kay, T (2020). Habitat Quality Index Assessment: Ranitata River, Arundel to Ealing. Prepared for Forest & Bird | Te reo o te taiao.
Ministry for the Environment (2022). Te hau mārohi ki anamata Towards a productive,sustainable and inclusive economy, Chapter 4: Working with nature. Aotearoa New Zealand’s First Emissions Reduction Plan.
NIWA. (2007). Fish screening: good practice guidelines for Canterbury. Prefpared for: Fish Screen Working Party: Environment Canterbury Fish & Game New Zealand Department of Conservation.
Petrove, N. And McEwan. A. (2024). Habitat requirements of freshwater fish in Aotearoa New Zealand. Department of Conservation. Refer www.doc.govt.nz under Publications.
Seddon, N, Smith, A, Smith, P, Key, I, Chausson, A, Girardin, C, House, J, Srivastava, S, and Turner, B. (2020). Getting the message right on nature-based solutions to climate change. Online: https://doi.org/10.1111/gcb.15513
Tukua Nga Awa Kia Rere | Making Room for River. Forest and Bird (2022) www.forestandbird.org.nz/roomforrivers
YouTube Resource: Braided Rivers Seminar 2022 by Tom Kay – Forest & Bird https://www.youtube.com/watch?v=YG-8ZcQgx6A
Williams, G. (2017). Natural character guidelines for the management of gravel-bed rivers in New Zealand.
Fish & Game, Forest & Bird and Choose Clean Water have written this practice note to communicate their expectation on how regional councils should implement the National Policy Statement for Freshwater Management 2020 (NPS-FM) into their regional plans. This is one in a series of practice notes which have been prepared on various topics relating to NPS-FM implementation.
