DOC is working to stop the decline of Ō Tū Wharekai wetlands.

DOC is working to stop the decline of Ō Tū Wharekai wetlands through intensive management, researching and trialling new methodologies and raising awareness of the plight of wetlands by education and involving the community.


Below is an outline of the aims and objectives for our work at Ō Tū Wharekai.

Protect water quality and habitat

  • Water quality is monitored, and management is undertaken to support wetland values.
  • Braided rivers, red tussock and sedgeland swamps and turf communities are protected by minimising threats such as weeds. Degraded wetland habitat is restored, specifically in areas dominated by willow, broom and ex-pasture by fencing and restoration planting.

Protect plant and animal life

  • The diversity and abundance of a representative range of indigenous species and guilds are maintained or enhanced; i.e. braided river birds, waterfowl, lizards, galaxid fish, freshwater mussel beds and kettlehole turfs
  • Populations of threatened animals and plants are protected and enhanced.

Protect history and cultural values

  • Cultural harvest opportunities are explored through State of Takiwa and implemented where possible
  • Historic sites on land managed by DOC are identified and managed

Actively involve the community

  • The project assists land managers in learning and practicing sustainable farming practices in the management area.
  • Facilities and opportunities for the public to visit the site are improved and awareness of wetland values are increased
  • The community appreciates the wetland and is fully involved in conservation at the site.


Understanding how wetlands and their inhabitants function, and sharing this information with other wetland managers, is an important part of Ō Tū Wharekai. Several research projects have been carried out under the Ō Tū Wharekai project. Some of these were done by DOC, and others in partnership with outside agencies.

Ō Tū Wharekai’s research objectives are:

  • Research undertaken at the site contributes to knowledge about wetland ecology and management
  • Survey and monitoring projects contribute to development of national wetland monitoring tools

Some research examples are:

  • Cultural health assessment of Ō Tū Wharekai
  • Determine the breeding success and impacts on wrybill/ngutu parore in the Rangitata and Rakaia rivers
  • The diversity of algae in rivers and streams
  • Monitoring the ecological integrity of wetlands within Ō Tū Wharekai
  • Determine fire ignition thresholds in grasslands: trigger points for setting activity controls on public conservation land in Canterbury (Heather Wakelin, University of Canterbury)
  • Understanding of the pre-human landscape status of the Lake Clearwater, Lake Emma and Māori lakes in the Hakatere Conservation Park through paleoecological research (Anita Staniland, University of Queensland)
  • Interaction between water flow, island characteristics and predation risk by introduced mammalian predators on the Rangitata River (Georgina Pickerall, University of Otago)


Key objectives when the wetland project first started:

  • Complete an inventory of all the key species and guilds
  • Set up permanent monitoring regimes
  • Measure trends of representative species over time and management regimes

Some of the monitoring regimes established to date include:

  • Scree skink survival
  • Long-jawed galaxid abundance
  • Ephemeral turf condition
  • Seasonal waterbird counts
  • Off-track vehicle use
  • Establishment of a weather station
  • Include Ngāi Tahu cultural values assessment in inventory and monitoring programmes

Managing the threats

With the inventory phase completed and monitoring regimes established, DOC is moving into intensive management. Some of the management that is occurring includes:

    Willow control. Photo: G Conway.
    Willow control

  • Removal of grey and crack willow around the lakes and streams to improve hydrology
  • Broom and lupin control on the upper Rangitata River to enhance river bird habitat
  • Fencing to protect vulnerable areas from vehicle damage
  • Riparian planting to improve water quality and enhance habitats
  • Establish recreational facilities to reduce disturbance to wildlife and impact on flora by visitors while providing for an enjoyable experience (see the Recreation plan)
  • Support community trapping initiatives to reduce predation of waterfowl

As well as containing high wetland and other biodiversity values, Ō Tū Wharekai is highly valued for its recreational opportunities.

Recreation plan

A recreation plan has been written to consolidate the planning directions for recreational activities and facilities in Ō Tū Wharekai (the Ashburton Lakes and upper Rangitata River.)

It has been developed in consultation with the local community, and incorporates comments provided by groups and individuals into the initial discussion document.

View the Ō Tū Wharekai Recreation Plan

Outcomes report

This report describes the conservation outcomes for the site and community engagement for 2007-2011.

View the Ō Tū Wharekai outcomes report 2007-2011

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