Environment Southland is replacing the Stead Street pump station with a new facility housing two new fish-friendly pumps. The pump station is part of a comprehensive flood protection scheme that helps to protect Southland’s largest urban centre, Waihōpai Invercargill (population 57,000+) and nationally critical infrastructure (Invercargill airport) from inundation. Stead Street also provides an essential transport link between Otatara and Invercargill.
While much of Waihōpai Invercargill is low-lying, the airport is close to sea level. It is protected from inundation during flooding and storm surge by a comprehensive drainage network, including stop banks, ring drains and pumps. Several of these assets are owned and maintained by Invercargill City Council, with the remaining assets managed by Environment Southland.
The new pump station is being built beside the existing structure and will house two fish-friendly pumps manufactured by a supplier in the Netherlands. The project aims to protect the area from inundation for the next 50 years. This pump station is critical to the 116 properties in the immediate area and is a lifeline for the airport, supporting 320,000 passengers plus freight each year.
Unlike the original pumps, the new pumps allow for the safe passage of native fish, including large tuna or freshwater eels. Their design is based on Archimedes' screw pump technology, where fish are transported up through the pump without getting harmed. They are very light, so don’t require a lot of power to operate and they are very simple, requiring much less maintenance.
Environment Southland took delivery of the twin pumps in early September 2022 and construction on the new pump station in commenced in October of the same year. By June 2023, the building was taking shape, and by August, significant progress had been made laying the outlet pipes from the new pump station site across Stead Street to the New River Estuary where a viewing platform is to be constructed.