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Orari River Protection Group

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Summary

  • The Orari River originates in the foothills of the Southern Alps Ka Tiritiri-o-te-Moana and flows through a gorge before reaching the Canterbury Plains. Geomorphologically a braided river ecosystem, the lower reaches have been confined by stopbanks, levees, willows, invasive weeds, and agriculture (top image & Fig. 1). In spite of this, the upper reaches and gorge are largely pristine and the lower reaches still attract breeding colonies of endangered river birds.
  • The River Protection Group formed in 2003 to prevent the construction of a dam and irrigation project, both of which would have contributed to climate change. Protecting the fragile ecosystems and with them, critical life-supporting ecosystem services that would have been lost had the dam been built, is far more cost effective than restoration.
  • They have expanded their activities to protect wildlife through trapping programme, with ambitions to expand their protection programme along the length of the river.

  Our Places

Other sections

Home > Nature-based solutions > Mid Canterbury > Orari Rivercare Group

Summary

  • The Orari River originates in the foothills of the Southern Alps Ka Tiritiri-o-te-Moana and flows through a gorge before reaching the Canterbury Plains. Geomorphologically a braided river ecosystem, the lower reaches have been confined by stopbanks, levees, willows, invasive weeds, and agriculture (top image & Fig. 1). In spite of this, the upper reaches and gorge are largely pristine and the lower reaches still attract breeding colonies of endangered river birds.
  • The River Protection Group formed in 2003 to prevent the construction of a dam and irrigation project, both of which would have contributed to climate change. Protecting the fragile ecosystems and with them, critical life-supporting ecosystem services that would have been lost had the dam been built, is far more cost effective than restoration.
  • The Group has subsequently expanded its activities to protect wildlife through trapping programme, with ambitions to expand their river protection programme along the length of the river.

Context, origins, and purpose of the group

In 1999, the Rangitata South Irrigation Limited (RSIL) was formed with the aim of bringing reliable irrigation water to 16,000ha of land between the Orari and Rangitata Rivers by damming the Orari River. The proposal was met with strong opposition from the Orari Catchment community. This ultimately led to the formation of Orari River Protection Group in 2003 with the following objectives:

  1. To retain the gorge in its free-flowing state
  2. To retain the integrity of the river hydrology
  3. To sustain, protect and enhance the natural character and ecological values of the Orari River catchment for present and future generations
  4. To maintain public access to the Orari River as an educational and recreational resource
  5. To advocate for greater protection of the upper Orari River and catchment in District and Regional Plans
  6. To recognise the potential for over-allocation (of water), and advocate for the use of the Orari River Catchment Management Strategy

In 2005, a public meeting held in Geraldine resolved that a management strategy was needed for the Orari River and its catchment, from its headwaters to the sea. The community, with support from Environment Canterbury and NZ Landcare Trust, spent three years creating the Strategy, whose Mission Statement is to:

“To sustainably manage the Orari River Catchment, integrating its ecological, social, economic and cultural values.”

Key Actions

  • Working together in consultation with experts, in 2011 the Group succeeded in having the Orari gorge recognised as an Area of High Naturalness by Environment Canterbury as part of their Land & Water Plan, due to its clean water, outstanding native vegetation, and biodiversity
  • Applied for and granted funds from Environment Canterbury Biodiversity funding for protection work in the gorge, leading to:
  • Five years of manual and helicopter (in gorge) weed control
  • Protecting rare native plants including pink broom (C. torulosa)
  • Trapping predators to protect breeding colonies of endangered black-fronted terns, critically endangered black-billed gulls and other river birds plus other native species in the gorge; monitor outcomes
  • Collaborates with DOC, LINZ, BRaid, ECan and other catchment groups, land-holders, and community members with the goal of making the river predator-free by expanding multiple trap-lines
  • Work with local contractors Hobbs & Banks and Rooneys earthmoving to create suitable breeding habitats (gravel island formation) for endangered colony nesting birds
  • Quarterly water quality testing
  • Engage with the community as a whole to hold events and fun days on the river
  • Advocate to minimise impacts of recreation/industry on the natural and environmental values

Before Image After Image

Fig. 1: Orari River at Burdon Ford facing North. The road crossing the river is Burdon Ford. These images show how much the river has been constricted by agriculture and weed since the late 1960s (B&W) and 2020 (colour). Forcing   the river to flow in a single channel (the image at the top of the page was   taken just above the Burdon Road ford facing north).  Image credits (left) Canterbury Maps historic aerial images; (right) Google Earth.

How this helps mitigate and adapt to the impacts of climate change

  • Protecting the fragile ecosystems and with them, critical life-supporting ecosystem services that would have been lost of the dam had been built, is far more cost effective and both ecologically and climate friendly than trying to reverse negative impacts. Dam waters builds up to create an unnatural stagnant lake that eventually kills most of the original ecosystem that once existed there. Everything—plants, forests, the insects, reptiles, microorganisms and fungi in the soils crucial for sequestering carbon—are all drowned. Bacteria and methanogens in the lake decompose the dead, emitting CO2 and methane. This bubbles to the surface adding more greenhouse gases into the atmosphere.
  • Enhancing forest bird habitat by removing weeds and trapping predators helps protect ecosystem services including carbon sequestration and nutrient recycling. These long term carbon sinks far exceeds the short-term benefits of carbon drawdown by exotic trees. Wetlands and springs help act as a buffer against droughts, predicted to have an increasing severe impact on North Canterbury.
  • Advocacy and actions to restore the braidplain will also reduce the physical exposure to and mitigate the impact of floodwaters, which are predicted to become more frequent and more severe.
  • Actively engaging in public awareness of the problems facing river, including the risks of flooding from a severely restricted braidplain (Top image and Fig. 2) will help the community make better-informed decisions about the future management of the river.
  • This in turn reduces the socioeconomic vulnerability to hazard impacts and strengthens people’s resilience to disasters.

More information

     Setting up and using the DOC200 trap