B1: Extent (and values) of monitored natural inland wetlands is increasing

Baseline only

How are we doing?

Ninety percent of freshwater and natural wetlands within Waitaha Canterbury have been drained and developed for agriculture or urban development. Our 2019 baseline will provide our measure to track how we are doing.

B1: Extent (and values) of monitored natural inland wetlands is increasing

Baseline only

What we are measuring and reporting

Reporting on inventoried extent (hectares) of natural inland wetlands across Waitaha Canterbury every five years from 2024 – next update 2029 compared to 2019 baseline (with interim results in 2028).

Reporting annually on monitored values (condition) of assessed natural inland wetlands in Waitaha Canterbury (~50 wetlands each year). After 10 years we repeat year one assessments and begin reporting on changes and trends in wetland condition regionally.

Baseline measure

Extent: ~43,187 hectares of natural inland wetlands is the inventoried baseline in the Canterbury Wetland Inventory 2019.

Values (condition): The ~50 natural inland wetlands assessed in-field each year over 10 years from 2024.

To meet the target

Wetland extent, connectivity and function should be increasing across the region, relative to the baseline year and Waitaha Canterbury’s network of natural inland wetlands should be sustained.

This map shows the Waitaha Canterbury region with boundaries and names for regional catchments. For each catchment, the known hectares of natural inland wetlands recorded in the Canterbury Wetland Inventory 2019 is shown as the baseline inventory.

Wetland values monitored in 2025/26

For 2025/26, our wetland monitoring programme involved field survey of 54 wetlands regionally. This is the second year of implementing Environment Canterbury’s long-term regional wetland monitoring programme, which targets ~50 wetlands each year. The report Wetland Assessments 2025/26 Environment Canterbury Science Summary: R26/27 provides information about the programme and wetlands monitored this year, including native plants and animals on site. Notably, of the 54 wetland sites of various types and sizes visited this season, 37 host Threatened and At Risk plants or animals. These include highly mobile fauna, the Australasian bittern/Matuku-hūrepo (listed in the National Policy Statement for Indigenous Biodiversity (NPSIB)); and the diminutive and threatened native plant, the native swamp buttercup (Ranunculus brevis).

Occurring only on the eastern side of the South Island, swamp buttercup typically grows within shallow water, marsh, and fen habitats and is often found in shallow pools or on water margins. It is highly vulnerable to weed invasion and changes in wetland hydrology.

The observation of rare and uncommon species at many monitored wetlands highlights the importance of wetland habitats for vulnerable native species.

This map shows the Waitaha Canterbury region with boundaries drawn for each territorial authority (city and district council). The number within each territorial boundary shows the number of wetlands field surveyed in that area in 2025/26, out of the total of 54.

Why are we measuring this?

Despite their decline, wetlands remain a vital part of Waitaha Canterbury ecosystems. They provide a haven for a vast range of native plants and animals, including rare and threatened species. They offer protection against flooding, can store large amounts of carbon, and function as a filter between land and streams, rivers, lakes, and sea.

The ecosystem services that natural inland wetlands provide make them essential to help protect our freshwater quality and to buffer the impacts of climate change. One hectare of wetland in Aotearoa is estimated to provide ecosystem services to the value of ~$59,000 NZD each year (Eco-index. 2024). These services include regulation of water flows, ecological waste treatment, maintenance of indigenous biodiversity, cultural connection/whakapapa, provision of food resources/mahinga kai, and opportunities for recreation and tourism.

The often-quoted figure of 90 per cent wetland loss for Aotearoa New Zealand since European settlement also applies to Waitaha Canterbury where wetlands were drained for urban and rural development. More recent analysis shows that wetland loss nationally and regionally continues to occur (Pompei & Grove, 2010; Denyer & Peters, 2020; Dymond et al., 2021). Although fragmented and often small, remaining wetlands throughout the region present a diversity of wetland types which hold important biodiversity values (Richardson et al., 2015), and small wetlands still contribute significantly to ecological function (Dymond et al,. 2021). 

The National Policy Statement for Freshwater Management (NPS-FM) directs regional councils to identify, map, inventory, and monitor all natural inland wetlands greater than 0.05 hectare within their regions by 2030. Councils should also include, in their resource management plans, specific policies, rules and other methods to prevent further loss of extent of natural inland wetlands, to protect their values, and promote restoration. Directed by the NPS-FM, every regional council must establish methods for monitoring progress towards achieving target attributes and environmental outcomes, including for natural inland wetlands.

How do we measure the result?

Natural inland wetland extent

The Canterbury Wetland Inventory 2019 provides us with a baseline measure of extent, i.e. the hectares of natural inland wetlands in the region within the dataset at a fixed point in time. Work on this wetland inventory began in 2012 with initial regional coverage completed in 2019. Natural inland wetland extent has been inventoried primarily through desktop assessment of aerial imagery and sites verified by field survey, including state of the environment monitoring at priority sites. The inventory describes areas of wetland habitat to various degrees of accuracy and detail for known wetland extent, type, condition, and ecological significance. Approximately 11,000 hectares (~25 per cent) of our inventoried wetlands occur on land administered by the Department of Conservation Te Papa Atawhai (DOC).

Whilst care has been taken in preparing the Canterbury Wetland Inventory, information is considered indicative. The inventory is maintained as a dataset, with updates and edits made as new information becomes available. The Canterbury Wetland Inventory 2019 provides a baseline from which to monitor and report change in wetland area.

Natural inland wetland values

The regional wetland monitoring programme uses standard monitoring methods developed for regional councils to measure wetland values. The methods utilise a set of ‘indicators’ to generate a wetland condition indices wetland condition indices (PDF file, 13.4MB) (WCI) score and wetland pressure index (WPI) score. Overall scores and scores for individual ‘indicators’ can then be compared over time to report changes in wetland condition.

Over summer 2025/26, our scientists carried out ground surveys (field assessments) of 54 wetlands as part of the regional wetland monitoring programme. These assessments form part of a rotational approach covering ~50 wetland sites per year. After 10 years, repeat assessments of sites will begin to uncover trends in wetland condition at a regional scale. Wetlands assessed in our 2025/26 monitoring year included important habitats with high ecological value and/or community interest. Around one third of the assessments (16) informed resource consent application processes; one assessment occurred in relation to Environment Canterbury’s compliance function, and one supported operational biodiversity work. The remainder were high value priority wetland sites.

What work have we undertaken to contribute to this outcome?

We work with Papatipu Rūnanga, landowners, and the community to protect, preserve and restore wetlands across Waitaha Canterbury.

Environmental regulation and protection is one of our core services. To help achieve outcomes, we undertake targeted consent compliance monitoring around the region. Consenting helps sustainably manage and protect our natural environment and resources. We aim to deal with environmental risks before they become incidents and cause damage.

Any activity in and around natural inland wetlands must comply with rules in the Canterbury Land and Water Regional Plan (CLWRP). We also promote wetland conservation beyond regulatory requirements to increase the total area of wetlands through restoration and construction.

Our regional wetland monitoring programme enables us to build our understanding of natural inland wetlands in Waitaha Canterbury and to report progress towards the environmental outcome for these wetlands through our website.

Who else plays a role?

Individual landowners, Queen Elizabeth Ⅱ National Trust/Ngā Kairauhi Papa (and other covenanting agencies), and government departments including Toitū Te Whenua/Land Information New Zealand and DOC who directly administer land containing wetlands, all play a significant role in wetland conservation. Wetlands administered by DOC also make up a significant proportion of the region’s known inventory of wetlands.

Landowners conserve wetlands beyond regulatory requirements and hold site-specific knowledge critical to effective wetland management, especially across the lowland Canterbury Plains. We gratefully acknowledge the support and cooperation of landowners. Their interests in, and ongoing efforts toward, the protection and management of natural inland wetlands are the foundation to sustaining these important ecosystems across Waitaha Canterbury.