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.
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 continues to increase (Pompei & Grove, 2010; Denyer & Peters, 2020). 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).
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 that we currently know of. 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 from verified site visits, in addition to 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 occurs on land administered by the Department of Conservation/Te Papa Atawhai (DOC).
Whilst care has been taken in preparing the Canterbury Wetland Inventory 2019, all information is considered indicative. It is also ‘live’, meaning inventory updates and edits are ongoing. The Canterbury Wetland Inventory 2019 provides a baseline from which to monitor change.
Natural inland wetland values: The regional wetland monitoring programme uses standard monitoring methods developed for regional councils. The methods utilise a set of indicators to generate wetland condition indices (PDF file, 13.4MB) (WCI) and wetland pressure indices (WPI). Each indicator component is scored. These indicators and indices can then be compared over time to report changes in wetland condition.
Over summer 2024/25, our scientists carried out ground-surveyed assessments of 55 wetlands as part of the regional wetland monitoring programme. These assessments form part of our rotational monitoring programme which will cover ~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 2024/25 monitoring year included important habitats with high ecological value and/or community interest. Over half of the assessments informed resource consent applications or compliance processes.
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.
Where can I find more information?
Read about how crucial our wetlands are for biodiversity in the region.
Download monitored wetland values for 2024/25: Wetland Assessments 2024/25 Environment Canterbury Science Summary R25/30 (PDF, 3.7MB)
Download Regional wetland monitoring: A programme for Canterbury. Environment Canterbury Science Methods and Procedures. June 2025 (PDF, 13.4MB).
