Wetlands projects

Dickeys Reserve Carex secta swamp invaded by willow

Now in its fourth year, a collaborative project with the Department of Conservation (DOC) and Christchurch City Council (CCC) is continuing to restore the lowland swamp ecosystem at Dickeys Reserve.

• Willow control: Contractors have carried out willow control work to complement work already completed by CCC staff.
• Biodiversity benefits: This restoration effort is helping to protect critical habitat for native species, including the critically endangered Matuku-hūrepo / Australasian bittern, as well as a diverse range of other native flora and fauna. 

Willow control and riparian management remain priorities for the Waihao Wainono Catchment Community Group (WWCCG).

• Upper catchment efforts: With strong support from landowners in the upper catchments, the group has coordinated weed control efforts and the removal of dead vegetation following spraying. This work has been funded with contributions from Waimate District Council, Fonterra, Morven Glenavy Irrigation Company, Port Blakely Forests, individual landowners and us.
• Lower catchment efforts: In the lower catchment we have been working alongside Te Rūnanga o Waihao to identify priority areas for mahinga kai and biodiversity protection and enhancement. Funding has supported weed control and planting at Te Punatarakao, as well as a follow up survey of tuna (eel) populations that were first assessed in 2016. Planning for further work in partnership with Waihao will begin early in the next financial year.

Dense native wetland vegetation replaces closed willow canopy. Photo credit: Gary Boyd

This year saw a significant expansion in weed control efforts, with 1,400 hectares treated - roughly double the area covered in previous years. This increase reflects a larger budget and a coordinated effort to accelerate progress.

• Work carried out: Work was carried out across 18 management blocks.
• Contractor and team support: Multiple contractors supported the core Weed Strikeforce team to ensure the full budget could be delivered, despite a delayed start to the season. A total of $170,000 was allocated to contractor work, with $202,000 supporting the DOC team.
• Results: Only small pockets of juvenile grey willow remain on the western shore outside the Harts Creek/Lakeside area, marking a significant step forward in long-term control. 

This expansion demonstrates accelerated progress in weed control and ecosystem restoration across the region.

Haldon Pastures wetland showing the extent of controlled willows. Note that the central area has since been controlled

This wetland, located in greater Haldon Pastures, is unique - fed by two spring heads rather than the nearby Hororata River.

It is also closely connected to important mudfish habitat and areas classified as nationally significant.

• Willow control: All mature willows in the main wetland area have been controlled, except for two spring heads, they still have willows present.
• Funding: We contributed $45,000 of funding toward woody weed control, with an additional $30,000 secured from other sources to support restoration efforts.
• Goal: Continue the control work and are successful in removal, we can provide a high likelihood of protecting the wetland long-term.

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The Scamander Wetland, connected to Lake Coleridge and fed by Scamander Stream, is a flagship restoration project between the Coleridge Habitat Enhancement Trust (CHET) and us. This project takes a proactive “before it’s too late” approach to protect the wetland’s ecological integrity.

• Threats: This high-country wetland is under threat from invasive willows, which are rapidly encroaching on sensitive ecosystems.
• Funding and results: To date, $66,000 in funding from us and CHET has enabled the control of approximately 90% of willows within the wetland.
• Next steps: Future funding is expected to support the next phase of work, which will focus on controlling wilding conifers. Planning for this is already underway. In the meantime, our staff will target the remaining 10% of willows, and a follow-up plan is being developed with local landowners to manage any future regeneration. 

Scamander Wetland before willow control

Scamander Wetland after willow control

The hardy kaimahi of Wildlands Consultants head into the hoar frost to control willows in Lees Valley.

Lees Valley may be one of the smaller intermontane basins of Canterbury, but it contains a richness of wetland biodiversity values.  While most wetlands in the valley remain free of invasive willows, this aggressive species has begun to spread, threatening freshwater ecosystems and displacing native biodiversity.

• Current work: Ongoing work across the valley is focused on eliminating willows from wetlands and other freshwater habitats. Efforts have so far concentrated on private land, particularly around Duck Creek, where ground-based contractors and landowners have made significant progress in controlling willow infestations.
• Ownership: The valley includes four major private landowners, with the remaining land publicly owned.
• Future work: Target mature willow trees across all freshwater environments, followed by the removal of seedlings and saplings. Once complete, the wetlands and associated ecosystems in Lees Valley will be free from the threat of willow dominance—ensuring long-term protection for this ecologically valuable landscape. 

Located on the outskirts of Christchurch, and once the south branch of the Waimakariri River, the Ōtukaikino catchment retains high biodiversity values linked with its historic braided river landform and clean freshwater systems.

• Threats: Invasive weeds displacing native vegetation.
• Support: For many years, stakeholders including CCC, community groups and landowners and us have worked together to manage weeds spread across the catchment.
• Work: Recent contractor work focused on two key sites, targeting willow species, Chilean flame creeper, lagarosiphon and old man’s beard.

These efforts are part of a broader, coordinated approach to protect and enhance the catchment’s unique ecological values.

Old Man Beard infestation before control

Otukaikino after weed control

The Weed Strike Force team marking a patch of Juncus geradii prior to controlling it at Saltwater Creek

This year we trialled an extension of scope for the DOC Te Waihora Weed Strike Force team, tasking them with weed control beyond the Te Waihora core area.

To eliminate specific invasive species from three ecologically significant sites:

• Kaitorete, ice plant and wilding conifers are threatening one of the most intact dune ecosystems in New Zealand.
• Te Aka Aka is home to an invasive rush, Juncus gerardii, which poses a serious risk to native turf plant communitiesand is only known from three sites in Canterbury.
• Ōtūkaikino a wetland sedge, foxtail sedge, is currently at low frequency. It is the only known location in Canterbury, so eliminating it here will protect all freshwater wetlands of Canterbury.  

What's been done: The work has included mapping extent, search and control and in the case of Juncus gerardii trialling different methods to determine what will work best.

Next steps: Work will continue until annual surveillance and control efforts reveal no more individuals at each site. 

The  Kaikōura district is renowned for is rugged coast and marine environment, but there are gems of wetlands tucked away out of sight. The Kahutara Lakes include Rotorua, Rotoiti, Kowhai and Leg of Mutton and account for a third of the wetlands in the district with a combined area of more than 80 hectares.

• Protection: A QEII covenant to protect the values of Leg of Mutton has been approved and ready to progress once a fence to exclude stock and feral deer is completed. 
• Biodiversity: These lakes are perhaps best known for their abundant bird life, including the bird of the century pūteketeke /Australasian crested grebe.
• Unique species: Leg of Mutton is also one of only two sites in the district where the swamp nettle (Urtica perconfusa) can be found. With its powerful sting, it’s a plant you’re more likely to feel than see, but it plays a vital role in the ecosystem. Native nettles like this one are the sole food source for the larvae of the red admiral butterfly, a striking and iconic native species. 
• Ongoing work: Ongoing willow control is the final step in this restoration project, which will enhance habitat for a range of native species, including the swamp nettle, marsh crake, and the kautuku / Australasian bittern.

Leg of mutton willow removal

Red admiral butterfly

Swamp nettle (Urtica perconfusa)