Te Anau Basin Flood Management Project

Flood protection in the Te Anau Basin has been a priority since the 1980s, when stop banks were constructed along the Whitestone River in response to repeated flooding. These defences have played a critical role in protecting productive farmland and key infrastructure, including road access and telecommunications that connect Te Anau with the wider region.

In 2010 and 2013, major flood events caused washouts at the Whitestone River Bridge on State Highway 94, cutting off access and disrupting essential services, including phone and internet for 2,000 residents. In response, Waka Kotahi installed erosion control groynes and repaired the washouts, later proposing gravel extraction downstream to reduce sediment build-up and increase the river’s flood capacity.

The Te Anau Basin Catchment Flood Management Project focuses on addressing deferred maintenance and improving the hydraulic capacity of the Whitestone River to reduce flood risk. Staff have identified a 10-kilometre section of true left stop bank—stretching 2.6 km upstream and 7.5 km downstream of the State Highway 94 bridge—that requires targeted works. Twenty deferred maintenance defects will be addressed as part of the programme.

Why these upgrades matter

This work restores sections of the Whitestone River stop banks to their intended level of service, improving Te Anau’s resilience to extreme rainfall and high river flows projected to increase due to climate change.

Removing willows and vegetation improves river capacity, reduces erosion and maintenance requirements, and enhances the stability of stop banks. It also supports broader climate adaptation goals by reducing sediment and contaminants, improving aquatic habitat, and preserving channel capacity.

By improving protection ahead of future flood events, this project helps reduce future repair and emergency response costs.