Taiari River restoration

Media coverage

RNZ Our Changing World reporter Claire Concannon visited the Waipori–Waihola wetland complex, part of the Taiari River catchment. She talked to Dr Chris Kavazos DOC freshwater technical advisor, Tumai Cassidy Māori cultural advisor and Paul Pope programme manager for Te Nukuroa o Matamata Jobs for Nature project about the research and restoration work in the wetland and the wider river system.

See the story and listen to the podcast: Looking to the future for a low-lying wetland | RNZ

Current restoration work

Kanakana in the Taiari catchment

A summary of a survey to re-assess the current distributions of kanakana (Geotria australis, piharau, pouched lamprey) in the Taiari River catchment using environmental DNA sampling and kanakana pheromone detection techniques. The data collected will inform the management of critical habitats required for kanakana and delineate priority catchments for future annual monitoring.

Kanakana in the Taiari catchment – results from the 2023 survey campaign. Kavazos and Richarson (PDF, 4,660K)

Vulnerability of freshwater ecosystems and species to climate change

The Taiari River has a diverse range of freshwater habitats and species, some of which are found nowhere else. This report describes how climate change is likely to affect these habitats and species.  

Examples from the report include: 

• Sea-level rise and extreme weather events could cause plants in the Lake Waipōuri/Waihola wetland complex to die, and shift the lakes to a more muddy, unhealthy system.  

• More rain in the surrounding hills may increase the amount of water in streams during extreme storms, allowing trout to enter areas where rare native fish are present. Trout are predators for these species and could wipe out their populations.  

• Hotter, drier summers are likely to reduce the water levels in the river and its tributaries to a point that could stress or kill fish. 

The report also outlines options to mitigate the effects of climate change, such as: 

• Protect wetlands and restore stream-side habitat to reduce the impact of drought and floods.  

• Manage invasive plants such as wilding pines to reduce the risk of wildfires.  

• Develop a regional plan to protect the rare native fish that are only found in Otago.  

• Diversify land use to reduce the reliance on irrigation and allocate water to ensure enough flow remains in the river.  

Read the report: Climate change vulnerability assessment of freshwater ecosystems and values of the Taiari River catchment, and management options (PDF, 24, 239K)

Impacts and risks of climate change on the catchment

This report provides detail of projected changes in the climate of the Taiari River area by sub catchment (Māniatoto basin, Strath Taiari and Lower Taiari Plain). These include:

• more dry days and less water in the river and its tributaries
• increasing air temperatures, more extreme hot days and fewer frosts
• increased average rainfall, with more intense events – extreme flooding is expected more often.

Read the report: Climate change impacts and risks for the Taiari River catchment (PDF, 18, 671K)

Matatū ki te taiao, climate resilience strategy

The development of matatū ki te taiao was identified as a central component of Te Mana o Taiari. An initial hui rautaki (strategy workshop) identified values held by the community and principles for resilience planning. Future hui will be held to co-design a work programme for climate resilience and adaptation.

Summary of the hui rautaki: Te Mana o Taiari – matatū ki te taiao hui rautaki, Shane Orchard 2022 (PDF, 3,078K)

A second hui considered potential kā tohu te taiao, indicators of climate-driven changes, and information sources that could be used to measure them.

Summary of tohu rautaki workshop: Te Mana o Taiari – kā tohu te taiao, Shane Orchard 2023 (PDF, 1,851K)

Taieri LUDO project

Ngā Awa supported and co-funded a project called LUDO (land use diversification opportunities) with farmers in the Upper Taieri Wai catchment group. The LUDO webpage has a link to a decision-support tool that enables farmers to look at opportunities to diversify within their current farming systems. It features podcasts and videos created to share information and support the work.

The work was facilitated by The Whole Story and developed by researchers Liz Dooley and Iona McCarthy. The Whole Story is a social enterprise that aims to inspire, facilitate and articulate conscious, holistic sustainability on farms. The decision-support tool was funded by the Our Land and Water National Rural Professionals Fund.

Research, values and restoration report

The conservation values, issues and priorities for action in the catchment were summarised in a report for DOC, published in 2020. This information provides useful background information for the Ngā Awa restoration work but is not DOC policy.

Taieri River review Ryder 2020 (PDF, 2,531K)

Te Nohoaka o Tukiauau/Sinclair Wetlands  

Te Nohoaka o Tukiauau/Sinclair Wetlands south of Dunedin contain river channels, pools, swamps and forested islands. The wetlands provide habitat for native plants, fish and birds and are valued as a wāhi taoka for mahika kai (food gathering), conservation, recreation and education.

The wetlands were returned to Ngāi Tahu in 1998. They are managed by Te Nohoaka o Tukiauau/Sinclair Wetlands Trust, which carries out weed control and replanting work. The goal is to protect, restore and promote the spiritual, physical, ecological and cultural values of the land and water, while allowing natural resources to be harvested.

Tiaki Māniatoto – Freshwater Improvement Fund

This project is run by Upper Taieri Wai – a catchment group formed by Māniatoto farmers and stakeholders. Its focus is enhancing water quality and the recreational, cultural, biodiversity and economic values in the Māniatoto district. The project is carrying out large-scale fencing, riverside planting and weed control, and developing areas for recreation.

Visit Tiaki Māniatoto for more information.

Te Nukuroa o Matamata

Te Rūnaka o Ōtākou is leading a Jobs for Nature-funded project called Te Nukuroa o Matamata to restore habitats and rejuvenate mahika kai in the lower Taiari catchment.

With Te Nukuroa o Matamata, we are researching where kanakana (lamprey) and kōkopu are currently present in the Taiari catchment. We are also studying tidal flows in the Te Nohoaka o Tukiauau wetlands by monitoring the salinity. These projects are an opportunity for local people and DOC staff to work together.

Salinity monitoring surveys, methods and results: Te Mana o Taiari salinity monitoring, Shane Orchard 2022 (PDF, 2,537K)

Treaty partner and mana whenua

DOC’s Treaty partner and mana whenua for this area are local hapū affiliated to Te Rūnaka o Ōtākou and Kāti Huirapa Rūnaka ki Puketeraki. These hapū have a long-standing intergenerational history and ongoing connection with the Taiari River. They claim kaitiaki (guardianship) over the catchment.

Mātauraka Māori

The Upper Taiari, Strath Taiari and Taiari Plains are all important areas for Kāi Tahu. More than 40 taoka (treasured) species, numerous mahika kai sites, and fortified, permanent and seasonal settlements are associated with the catchment’s waterways, lakes and wetlands. The entire catchment was a significant food source for mana whenua and provided an abundance of resources from inland weka to coastal īnaka.

Wai Māori freshwater issues

The Taiari River and its wetlands are associated with hundreds of mahika kai sites but many have been modified significantly. Those on the Taiari Plains were once much larger and deeper, and were interconnected in a complex network of waterways. The waterways had gravel beds, but these were covered by silt by the late 1880s, soon after gold mining began in the catchment.

Mana whenua have concerns about the following issues related to water in the catchment:

• over-allocation of water resources
• the effect of sedimentation from historical mining activities
• altered hydrodynamics of the Waipōuri River
• mixing of waters from different rivers
• more intensified land use affecting water quality
• wastewater discharges into the Taiari River.

See priorities as stated in the Kāi Tahu ki Otago Natural Resources Management Plan (2005).

About the river and its catchment

The Taiari River catchment is one of the largest in Otago, covering an area of more than 5,700 km². It includes the open landscapes and rolling tussock-covered hills that are typical of Central Otago. The river is 288 km in length – the fourth longest in Aotearoa New Zealand.

See a map of the Taiari river catchment (PDF, 10,676K)

Upper Taiari catchment

The top of the catchment is an area of tussock grassland in Te Papanui Conservation Park. The river flows over a series of steep rapids (known as Taiari Falls) before twisting and winding through the Styx basin scroll plains. Scroll plains are a rare feature of freshwater systems where a stretch of river meanders across a flat, wide area and creates a mosaic of oxbow lakes and channels.

The river then enters the Paerau gorge and flows into another network of scroll plains in the Māniatoto Plains. After a further narrow gorge, it enters an area that was once Tunaheketaka/Taiari Lake but was drained in the late 1940s. This upper part of the river, which includes the pristine Te Papanui tussock lands and the only scroll plain ecosystem in Aotearoa, makes the Upper Taiari Wetlands Complex one of New Zealand’s most significant wetland areas.

Strath Taiari and Taiari Plains

An almost 180-degree turn southwards marks a major change in the river. It flows along the eastern margin of the Rock and Pillar Range through the Strath Taiari Plain. Here, the river is characterised by deep gorges and is often inaccessible. Deep Stream, Lee Stream and other waterways join the Taiari along this stretch before it passes Outram and flows into the Taiari Plain.

There is a large wetland complex on the Taiari Plains where the river drains the Waihola-Waipōuri Wetlands. At this point in the past the river would have joined waters from Waihoropuka, which included Lake Tatawai, Potaka and Marama Te Taha. However, these wetlands were drained by early European settlers. The river finally passes through the Taiari Gorge before it flows into the Pacific Ocean at Taiari Mouth.

Trout-free waterways

The headwaters of the Taiari River are above the steep cascades of Taiari Falls. The falls provide a natural barrier that prevent trout from entering the upper 25 km of river and tributaries. This trout-free area provides extensive habitat for the Nationally Vulnerable native fish, Taieri flathead galaxias.

Scroll plains

The Styx basin and Māniatoto Plains contain the only scroll plains in Aotearoa. These wetlands are significant internationally and one of the world’s largest remaining examples of this type of ecosystem. The scroll plains provide important habitat for tuna (eels) and native birds. Other benefits include buffering high and low river flows.

Ephemeral wetlands

Ephemeral wetlands form in areas without an outlet on the surface and are not wet all year round. There are many ephemeral wetlands among the tributaries of the river in the Strath Taiari valley. One is Sutton Lake, New Zealand’s only inland salt lake, which is located in the rain shadow of the Rock and Pillar Range. The Taiari catchment contains more saline ecosystems than any other catchment in Aotearoa.

The ephemeral wetlands are associated with many rare and threatened plant and animal communities. These species have evolved special features to thrive in the unique environments they inhabit.

Wetland complexes

The Lake Waipōuri/Waihola complex would have covered much of the Taiari Plains before large-scale drainage occurred in the 1850s. Despite the dramatic losses in the area of wetland, the remaining ecosystem provides habitat for 131 species of native plants and at least 46 species of birds.

Te Nohoaka o Tukiauau/Sinclair Wetlands is owned by Te Rūnanga o Ngāi Tahu and managed by Te Nohoaka o Tukiauau/Sinclair Wetlands Trust as an important mahika kai and wāhi taoka (culturally significant) site.

Threatened species in the catchment

Plants

The Taiari catchment contains important populations of threatened plants. Its unique landscapes provide habitat for 81 At Risk and Threatened species. Plants with a threat status of Nationally Critical include:

• Ceratocephala pungens
• Crassula peduncularis
• Lagenophora montana,Papataniwha
• Lepidium juvencum, scurvy grass
• Lepidium kirkii, salt pan cress
• Lepidium sisymbriodes
• Lepidium solandri, Maniototo peppercress
• Puccinellia raroflorens,saltgrass
• Simplicia laxa
• Triglochin palustre,marsh arrow grass.

Fish

There are 20 species of native fish in the catchment, many of which are found nowhere else. 12 species are classified as At Risk or Threatened. Fish with a threat status of Nationally Endangered or Nationally Vulnerable include:

• Eldon’s galaxias
• Central Otago roundhead galaxias
• dusky galaxias
• Taieri flathead galaxias
• lamprey, kanakana.

Birds

The Taiari catchment contains important habitat for more than 70 species of birds. Many of these are waterbirds associated with the many wetlands. Birds in the catchment with a threat status of Nationally Critical and Nationally Vulnerable include:

• Australasian bittern/matuku-hūrepo
• black stilt
• white-faced heron
• black-billed gull
• Australasian crested grebe
• banded dotterel
• black-fronted tern.

Lizards

Many different species of lizard live in the Taiari catchment. 10 species are found here and 9 of these are rare or threatened by habitat modification, fire and predation.

The lizard species include:

• Burgan skink
• Otago skink
• grand skink
• green skink
• southern grass skink
• cryptic skink
• Woodworthia Otago/Southland large
• jewelled gecko
• Oteake skink
• Oligosoma maccanni (McCann’s skink) Not Threatened.

Contact

If you have any questions or want to get involved, email us.

Email: info@doc.govt.nz