Wetlands

Wetlands provide some of the most valuable ecosystems in Southland.

Wetlands can include bogs, swamps, fens, shallow water and salt marshes, and are found from the coast to the high country.

90% of New Zealand’s wetlands have been cleared and drained in the last 150 years. But more and more landowners are seeing the value in restoring these unique landscape features because of the benefits they provide to water quality and biodiversity.

What is a wetland?

The Southland Water and Plan provides definitions for three types of wetlands.

• Wetland – means permanently or intermittently wet areas, shallow water, and land-water margins that support an ecosystem of plants and animals that are adapted to wet conditions
• Natural wetland – has the same meaning as a ‘wetland’, but specifically excludes wet pastures, damp gully heads, ponding of rainwater, pastures with rushes, artificial storage facilities, reservoirs, and erosion control structures.
• Regionally Significant Wetlands – are special wetlands listed in Appendix A of the plan, and mapped in Part B.

Why are they so important?

Did you know that wetlands support the greatest concentration of wildlife - more than any other habitat in New Zealand? Many of New Zealand’s native fish and bird species live in wetland habitats and depend on them for survival. Some birds migrate from overseas to feed in our wetlands. However, wetlands can only sustain healthy populations of wildlife if they are in good ecological condition.

The benefits of wetlands:

• they act as a filter – trapping sediment and nutrients and improving water quality
• they are part of the water cycle – which means they reduce the impact of floods
• they act as a buffer zone – protecting streams and waterways on-farm from erosion and nutrients
• they provide outdoor recreational opportunities – wetlands are great places to fish, duck shoot, and have picnics
• they provide important habitats – many native species of birds, fish and plants live in wetlands
• they help regulate river flows – they can retain summer water flows by releasing water slowly
• they have important cultural significance – wetlands are valued for mahinga kai (food gathering), medicinal plants for rongoā (Māori medicinal use), and mātauranga (knowledge)

How is Environment Southland protecting wetlands?

Environment Southland has proactively been taking steps to address wetland loss. We have complied with our state of the environment monitoring obligations and taken appropriate action when required.

Our wetlands work programme is aligned to the requirements of the National Policy Statement for Freshwater Management (NPSFM) 2020 regarding the mapping and monitoring of natural inland wetlands. The NPSFM 2020 requires the Council to map natural inland wetlands by 2030 and this work is underway.

We have made a considerable investment in wetland science, hiring a dedicated wetland scientist and updating our information on wetland loss and extent in the region, down to 0.5ha scale. Work is underway to ground-truth this based on priority areas and as resources and landowners allow.

The Council is involved in several national science and research projects, which will provide us with information on how to better manage wetlands in future, including for green house gases, biodiversity and water quality outcomes. We are also working on developing resources that will help landowners and others with constructing effective wetlands in our landscapes.

We’ve taken action on our land and we support community initiatives such as those by catchment groups and others, with wetland construction, restoration, and research on environmental effectiveness, e.g. treating contaminants. Financial support may be available through our Land Sustainability Mitigations Fund.

The Council is also piloting a ‘slow the flow’ initiative to reduce flood impacts and wetlands also have a role in this project. Read more about this project.

Now that the Southland Water and Land Plan is operative, we will monitor its efficiency and effectiveness for wetlands and report on the results, as required by resource management legislation.