Expressions of interest - source of stop bank construction materials

Invercargill City

Environment Southland is preparing to strengthen our flood and storm surge protection in Invercargill to meet the expected increase in extreme sea levels in the New River Estuary/Kōreti. To help achieve this, we are planning a programme of work alongside the Waihōpai River between North Road and Stead Street and the lower reaches of the Otepuni and Kingswell streams.

We’re seeking material sources, including highly weathered (rotten) rock that is less rain sensitive to enable a longer construction season. In the past, we’ve used local silt from nearby river flats but this material limits construction to long dry summers.

This work is scheduled to take two years, but Environment Southland would also like flexibility for a longer-term supply source. The suitability of the material and commercial details of a supply agreement will be considered at the next stage. If you have an existing rural property near Invercargill with exposed rotten rock or other suitable material, please email climate.resilience@es.govt.nz by 22 November with your contact details, photos of the material, and description of the location.