Our unique ecosystems

Braided rivers and wetlands are ecosystems that make our region unique and provide benefits to us both economically and environmentally.

Braided rivers

The habitats provided by braided river systems are becoming increasingly vulnerable as we place pressures on them for water use, such as irrigation and hydro schemes and recreation. They also face pressures from increased pests, weeds and pollution.

The Canterbury Water Management Strategy aims to halt the decline through its targets and goals with its focus on the integration of water and land management including the protection of indigenous biodiversity and water quality.

This is also integrated with the practice of kaitiakitanga or guardianship by Ngāi Tahu which applies to the ecological health of all waterways.

Braided rivers, such as the Waimakariri and Rakaia rivers, form a large part of the Canterbury landscape and are internationally rare river ecosystems.

They're characterised by their multiple, shifting channels, varying flows and shingle substrate. The rivers are an abundant supply of food and support many species that can't be found anywhere else.

Braided rivers provide feeding and nesting for twenty six species of native birds, with the majority classified as threatened and facing increased pressures as the natural character of these dynamic systems degrades.

Find out more about our Braided River Flagship Programme (PDF 1.09 MB) and the Natural Character of Braided Rivers (PDF 119.47 MB).

Wetlands

Wetlands once covered large areas of New Zealand. Now they are some of our rarest and most at-risk ecosystems, with approximately 90% having been lost in the last 150 years

Wetlands provide a habitat for a diverse range of plants and animals and are home to many rare and threatened species, such as the Australasian bittern and Canterbury mudfish.

Wetlands are also essential breeding areas for whitebait species and valuable habitat for eels.

Although wetlands now cover less than 2% of New Zealand’s land area, they are still home to an astounding 22% of all native bird species.

Canterbury has a great variety of wetlands from the coastal to alpine zones. Wetland water may be fresh, brackish or saline.

The types of plants and animals found in wetlands depend on the water — its amount, depth, permanence, temperature, the chemicals found in it, and its source — groundwater, surface water, rainwater or seawater.

Examples of the range of wetlands in Canterbury include:

  • Estuaries such as the Heathcote & Avon Rivers/Ihutai, and Ashley River/Rakahuri mouth
  • Coastal lagoons such as Wainono Lagoon
  • Margins of the shallow, brackish Lake Ellesmere/Te Waihora
  • Freshwater swamps such as Travis wetland in Christchurch City
  • Margins of the Ashburton lakes
  • Ephemeral “kettlehole tarns” in the glacial moraines of the high country

Each wetland and its mix of plants and animals vary with local conditions (for example, climate, water flow, altitude and substrate).

Several different types of plant and animal communities may be present in larger wetlands, and all wetlands may change over time as environmental conditions alter.