Wyndham flood infrastructure upgrade
Completed in May 2024, the Wyndham upgrade strengthened and extended the town’s flood infrastructure network, improving performance for 550+ residents and supporting local links across the lower Mataura.
In February 2020, very high flows in the Mataura River and its tributaries pushed Wyndham’s flood banks to near capacity, prompting the evacuation of more than 2,500 residents throughout the catchment. This upgrade focused on the highest-risk sections and closing low or discontinuous sections to restore and sustain agreed service levels and reduce near-term flood risk.
Key upgrades completed
The upgrades widened and extended the flood bank east of Wyndham Road; strengthened sections near the racecourse with widened banks and buttresses; removed trees and rebuilt low or unstable sections; and constructed a new 90-metre section at Ferry Street to close a gap in the network. Additional works included inspecting, repairing and extending culverts, headwalls and flapgates.
Why these upgrades matter
Enhancing Wyndham’s flood banks reduces flood impacts and helps the network perform as intended during high-flow events. Fixing low points, seepage and stability issues sustains the agreed level of service and supports homes, property and essential services as climate pressures increase.
Benefits
- Improved performance to the current design standard for Wyndham’s flood banks and related structures, reducing flood impacts on people, property and essential services.
- Closed gaps and strengthened priority sections to provide a more continuous, reliable network across the township.
- Designed for future adaptation, allowing staged adjustments as climate pressures and service-level needs change.
- Co-funded with central government (Kānoa), bringing forward Long-term Plan works and lowering costs for ratepayers.
Looking ahead
On 16 October 2025, new co-funding was confirmed through Kānoa – the Regional Economic Development & Investment Unit (MBIE) under the national Resilient River Communities initiative. This supports the next phase: the Mataura River Flood Resilience Project.
This phase applies 2D hydraulic flood modelling across the Mataura River—including Wyndham—to assess the capacity and performance of the existing flood infrastructure network, identify priority improvements, and inform an integrated, whole-of-catchment plan.
Alongside engineered works, the plan will consider nature-based measures where they add value (e.g. wetland restoration, detainment bunds, floodplain reconnection, riparian planting) to help slow, store and safely convey water while supporting ecological and cultural outcomes.
Building on insights from Murihiku Slow the Flow, the plan will test how engineered and nature-based measures can work together to reduce flood impacts. Nature-based measures such as wetland restoration, detainment bunds, floodplain reconnection and riparian planting can help slow, store and safely convey water while supporting ecological, cultural and community outcomes.
Insights from modelling and community engagement will guide the design and sequencing of future flood infrastructure works and longer-term adaptation options.
Funding and collaboration
This project is part of the national Resilient River Communities initiative — a joint programme between Kānoa and Te Uru Kahika – Regional and Unitary Councils Aotearoa. It is one of Environment Southland’s RRC projects, delivered with central government co-funding during 2021–2024.
