Flooding is the most common natural hazard we all face in New Zealand. As the world confronts a changing climate, we can expect the extent of flooding we experience to be affected through variations in rainfall, temperature and sea-level as well as river channel changes.

COVID-19 response and recovery programme projects

Managing the region's flood protection assets

Environment Canterbury manages 59 river control and drainage schemes from Kaikōura to Waitaki, with a total asset value of $673 million, higher than any other region in New Zealand.

These schemes help communities build resilience to flood events providing safety and security to productive land and protecting families, businesses and critical infrastructure. The strategic projects funded through this program are a legacy that will benefit Cantabrians for years to come.

Co-investing with central government offers the opportunity to kick-start projects that would have otherwise taken decades to fund through the current rating districts.

Taking action to adapt for climate change

Climate change is a major factor that is integrated across all aspects of operational decision-making at Environment Canterbury. With the expectation of more frequent and intense climate change–induced flood events, we are reviewing how our river management and flood protection schemes operate.

In December 2020 we confirmed $15.5 million in funding from the Ministry of Business Innovation and Employment’s Provincial Development Unit (PDU) towards a combined project value of $24.2 million in a co-funding arrangement.

Through this programme, the PDU will contribute 64 per cent of the cost of each project as a grant. The remaining 36 per cent will be co-funded by Environment Canterbury through a combination of contributions from partners, operational funding and rates.

The programme has a strong dual purpose of supporting the Canterbury Covid-19 recovery by generating employment for local contractors and workers to boost the regional economy, as well as providing climate change resilience and transformational opportunities for communities across the region

All projects must be completed by 31 December 2023.

Achieving environmental outcomes

In addition to the benefits of flood protection, Environment Canterbury now has a rare transformational opportunity particularly with respect to supporting the unique character of our braided rivers.

Taking a holistic approach to the health and vitality of our rivers is critical. By engaging with communities and partnering with mana whenua and other stakeholder groups we can accelerate regeneration of the natural environment and lead climate change resilience for the Canterbury region.

These initiatives strongly support our Strategic Directions (PDF File, 399.02 KB), enable a rapid start of valuable Braided River Revival/ Whakahaumanu Ngā Awa ā Pākihi works and will be a significant catalyst of positive change for current and future generations.

Funded Canterbury projects

Regionwide planting and berm transition
  • Investment: about $10 million

Planting trees in and around river margins is essential for flood resilience and protection of environmental values. River berms and margins are the strip of land directly adjacent to the active part of the riverbed. Planting in these areas provides a buffer which slows floodwaters and prevents bank erosion.

The margins of braided rivers are critical to their function and form and are rich in environmental values. Many are currently choked with weed growth which is likely to accelerate with climate change.

This natural infrastructure project generates multiple benefits in addition to flood protection, such as greater biodiversity, weed control, enhancements to wetlands and mahinga kai as well as opportunities to establish recreational areas.

Approximately 20 rivers across the region will benefit from this project.

Rangitata River 2019 flood recovery
  • Investment: about $8.5 million

A major flood event in December 2019 affected several alpine rivers in Canterbury. The Rangitata River broke out of the main channel at three key locations, causing a significant amount of damage to flood protection, roading, rail, farm, electricity supply and other assets. 

New flood protection and erosion control infrastructure and tree planting are required to protect communities and critical lifelines such as road, rail and communication networks.

A number of investigations are planned for the river as well as a substantive natural infrastructure programme focusing on planting, weed control, wetland enhancement and mahinga kai enhancement opportunities.

Waimakariri River flood protection at McIntoshs Bend
  • McIntosh bend stop bankInvestment: about $3.2 million 

The Waimakariri and Kaiapoi River stopbanks protect Kaiapoi township and the surrounding area from flooding. They are part of the Waimakariri-Eyre-Cust flood protection system which is maintained by Environment Canterbury.

In the 1960s, riverbank rock armour was installed to prevent erosion and stopbank breach on this very sharp bend.

Over the years the river has narrowed, and a deep scour hole has developed, increasing erosion vulnerability.

The new rock works will strengthen existing rock protection around McIntoshs bend and add new rock protection along the lower Kaiapoi River and adjacent stopbank.

Find out more about the Kaiapoi flood protection project

Ashley River/Rakahuri protection and fairway management
  • Investment: about $1 million

Ashley Rakahuri river

The Ashley/Rakahuri River is a key feature of the North Canterbury landscape that poses a significant flood risk to the communities living on its floodplain. This project involves removing exotic vegetation which is currently choking a 21 kilometre section of the river between Ashley Gorge and the Okuku River confluence, and in the Okuku River.

Braided rivers are a precious and iconic part of the Canterbury environment. We are prioritising the protection and restoration of their unique values as part of our Braided River Revival/ Whakahaumanu Ngā Awa ā Pākihi work. As a result of the introduction and invasion of weeds, predators, and human activities, braided rivers and their bird species, plants, native fish and insects are under threat.

Through this project in the Ashley River/Rakahuri, and others across the region, we are working on the restoration of our rivers normal braided character, which will in turn will enhance a range of natural biodiversity values, including natural braided river habitats.

Halswell/Huritini weed barrier replacement
  • Investment: $1,000,000

River weeding machine 

This project involves the replacement of a piece of critical infrastructure, currently at the end of its life, which is used to capture river weed cut in the Halswell/Huritini River.

Weed is cut from the riverbed in order to manage water levels (both ground and surface water) in the Halswell/Huritini catchment.

Cut river weed must be prevented from entering Te Waihora/Lake Ellesmere, which is a nationally important wetland of huge cultural importance.

If weed were to enter the lake, it would severely degrade water quality through the release of stored nutrients during decomposition.

Waiau township stopbank
  • Investment: $500,000

Waiau river

The existing banks leave the township vulnerable to breaching in floods from either the Waiau, Uwha or Mason Rivers.

Through the upgrade and linking of existing banks, these works will improve the resilience of the Waiau community to flood events which are predicted to become more frequent and of greater magnitude with climate change.