Te Anau Basin flood management project
Reducing flood risk in the Te Anau Basin has been a priority since the 1980s, when flood banks were built along the Whitestone River after repeated floods. These assets are part of the regional flood-infrastructure network and help reduce flood impacts on productive land and key services, including road and telecommunications links connecting Te Anau with the wider region.
In 2010 and 2013, major floods caused washouts at the Whitestone River bridge on State Highway 94, cutting access and disrupting phone and internet for about 2,000 residents. In response, Waka Kotahi NZ Transport Agency installed erosion-control groynes and repaired the washouts, and later proposed downstream gravel extraction to manage sediment build-up and improve flood conveyance.
The Te Anau Basin flood management project focuses on addressing deferred maintenance and improving the Whitestone River’s hydraulic capacity to reduce flood risk. Staff identified a 10-kilometre section of true-left flood bank—about 2.6 km upstream and 7.5 km downstream of the SH94 bridge—for targeted works. As part of this programme, 20 deferred-maintenance defects are being addressed.
Why these upgrades matter
This work restores sections of the Whitestone River flood banks to their intended levels of service, improving channel capacity and bank stability during high river flows.
Removing willows and other vegetation increases conveyance, reduces erosion risk and ongoing maintenance, and improves flood-bank stability. Selective planting for erosion control helps stabilise margins and support long-term performance.
By improving performance ahead of future flood events, the project reduces repair needs and emergency response pressures and helps shorten disruption for Te Anau and the surrounding areas.
Benefits
- Keeps critical services operating: sustains telecommunications and State Highway 94 access for residents, businesses and visitors.
- Supports Te Anau’s gateway role: helps maintain access to Fiordland National Park, underpinning the tourism economy.
- Reduces flood risk for rural land: lessens exposure for productive farmland and rural businesses.
- Delivers river co-benefits: stabilises margins, reduces sediment, and improves habitat for aquatic species
Funding and collaboration
- The project is being delivered with experienced local contractors and partners on an accelerated timeline, reducing transport needs, lowering costs and emissions, and improving delivery efficiency.
- It forms part of the national Resilient River Communities initiative and Environment Southland’s Before the Deluge 2.0 programme (announced in 2024), a $3.6 million investment co-funded by central government and Environment Southland through Kānoa – Regional Economic Development & Investment Unit.
- These investments aim to reduce flood impacts, sustain agreed service levels and shorten disruption after events, delivering environmental, economic and social benefits for communities across Murihiku Southland.
