Environment Southland is delivering a range of projects to reduce flood risk for Invercargill City, towns and rural areas across the region as climate pressures increase.
Flooding is the most frequent natural hazard in Aotearoa New Zealand. For more than 30 years, our region’s flood infrastructure network—including flood banks, floodways, pump stations, culverts, flapgates (tidegates) and rockwork—has reduced the impacts of flooding on people, property, productive land and essential services. As storm intensity and frequency increase, these assets face greater pressure. Ongoing investment in maintenance, upgrades and targeted adaptation is needed to sustain agreed service levels, recognising that flood defences reduce effects but cannot guarantee protection in all events.
Investment in flood risk reduction
With support from Kānoa – Regional Economic Development & Investment Unit, Environment Southland is delivering a multi-stage programme of flood infrastructure maintenance and upgrades.
Co-investment phase one (2020–2024)
Six projects were completed across the region, including critical works in Gore, Mataura, Wyndham and Invercargill.
Co-investment phase two (2024–2026)
Three projects in the Aparima (completed) and Ōreti catchments and the Te Anau Basin, reducing risk for Ōtautau, Winton, Dipton West and Te Anau.
Co-investment phase three (announced 16 October 2025)
Three projects, including further staged works in the Ōreti and Mataura catchments, and improvements to low sections of the Otepuni flood bank to stabilise and align overall performance with the recently upgraded Waihōpai River (true left) flood bank. Funding is for five years.
Catchment modelling
Advanced 2D hydraulic models are in use for the Mataura River and being developed for the Ōreti River and other priority catchments. These models inform flood-risk assessment and future infrastructure planning by showing how water behaves across the landscape under different rainfall and flow scenarios. They help us test options, identify priorities and support climate adaptation decisions—but they don’t predict or confirm exact outcomes.
