Work begins on Rangitata River stopbanks to improve flood resilience

Date: 17 Jun 2026

Canterbury Regional Council (Environment Canterbury) has begun construction on three new stopbanks designed to contain flows to the south branch of the Rangitata River during floods.

The south branch is a natural flood pathway for the Rangitata River and is expected to take the overflow during large flood events.

Why the work is needed

In 2019 floodwater broke out of the south branch and spread across surrounding land, causing widespread damage to flood protection infrastructure, farms, roading, rail, electricity supply and other assets.

The new stopbanks are part of ongoing work to improve flood resilience along the Rangitata River and better manage how water moves through the river system during high flows.

Councillor Ian Mackenzie, Community Preparedness and Response to Hazards Core Service Lead, says Environment Canterbury has a responsibility to take a long-term, system-wide view of flood risk across the Rangitata.

“This investment reflects the regional council and central government’s commitment to managing that risk in a structured and planned way – ensuring the river can function as intended during major events while protecting communities, critical infrastructure and livelihoods into the future.

“Through co-funding, we’re able to deliver major projects like this sooner. It’s important work that relies on local expertise and experience to get right,” he says.

Latest phase of Rangitata flood protection

Since 2019, extensive work has been done to repair damage and strengthen flood protection along the Rangitata River. This has included:

• reinforcing and stabilising stopbanks
• large-scale planting to support bank stability
• protecting key sites like the Peel Forest landfill
• clearing debris and vegetation across the riverbed.

More than 260 hectares of weed control has been completed across the catchment.

This latest phase of work is supported by $3M of co-funding through the Government’s Regional Infrastructure Fund, which covers 60 per cent of the cost. The remainder is funded by the council.

Construction is expected to be complete this winter.

Investigations into options to improve flood resilience around Arundel Bridge are underway, with vegetation clearance starting soon to improve channel capacity and flood flows.

Flood protection projects underway across South Cantrebury

This Rangitata and Arundel work is part of a wider flood protection programme Environment Canterbury is delivering across South Canterbury. 

Projects are underway on the Ōrāri, Ōpihi, Waihi and Pareora rivers, including stopbank work, vegetation clearance to improve flood capacity, and planting to strengthen river berms. 

Work has started on a project to realign the Waitarakao/Washdyke stopbank and drain inland, helping protect it from coastal erosion and rising sea levels, as well as creating extra room for flood flows. 

More recently, work has been completed on the Ōrāri River northern stopbank between SH1 and the KiwiRail line to restore its structural integrity and ensure continued flood protection.

Delivering flood protection sooner through co-funding

These projects are co-funded through the Government’s Regional Infrastructure Fund (RIF), which is administered by Kānoa – Regional Economic Development and Investment Unit.

Through the RIF, the Government has committed to investing $31 million into river resilience projects in Waitaha Canterbury between 2024 and 2029.

Co-funding means the Government covers around 60 per cent of project costs, with the remaining 40 per cent funded locally. This helps accelerate projects so improvements can be delivered sooner.

Environment Canterbury, alongside the regional sector, continues to advocate for greater shared investment to support projects like those now underway across Waitaha Canterbury.

Learn about stopbanks:

Find out how stopbanks help reduce flood risk and protect communities across Canterbury.

Learn more about flood protection