Stead Street pump station replacement

Environment Southland has replaced the Stead Street Pump Station with a new energy-efficient, fish-friendly facility. The project was driven by the age and type of the existing infrastructure, a requirement to bolster climate resilience for Murihiku Southland’s largest urban centre, Waihōpai Invercargill (population 57,000 +), and the aspirations of Ngāi Tahu ki Murihiku to have the health of the Kōreti New River Estuary restored.

The new pump station is part of a comprehensive flood protection scheme that helps to protect Invercargill City and nationally critical infrastructure (Invercargill airport) from inundation. Stead Street also provides an important road between Invercargill and Otatara.

While much of the city is low-lying, Invercargill Airport is close to sea level. Because of this, the airport is surrounded by a comprehensive drainage network, including stop banks, ring drains and pumps. Several of these assets are owned and maintained by Invercargill City Council, and some are managed by Environment Southland.

In 1984, the airport was extensively flooded to depths up to 3m through the terminal buildings. The primary sources of that floodwater – the Waihōpai River, Waikiwi Stream and Oreti River – underwent significant flood protection upgrades following the 1984 flood.

New pump station nearing completion June 2024

In March 2016, a phenomenon known as storm surge caused the sea to spill onto Stead Street, resulting in road closures and surface flooding of the land surrounding the airport. Storm surge occurs when sea levels rise during intense weather events. Climate change-induced sea level rise will increase the frequency and severity of these events.

The need to replace the Stead Street Pump Station was driven by the age of the existing infrastructure, which was installed in the early 1960s, and a requirement to manage fish passage with the introduction of the National Environmental Standards for Freshwater in 2020. The new pump station has been built beside the existing structure and houses two new fish-friendly pumps manufactured by a supplier in the Netherlands. It 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 harm. They are very light, don't require much power, and are simple, requiring much less maintenance.

Read the Fish Survey report here.

Funding

In 2020, Environment Southland secured $2.25 million of funding from central government as a contribution to assist in replacing the ageing Stead Street Pump Station, one of the council’s six climate resilience projects co-funded in the region.

The new Stead Street pump station 'Te Kupeka o Waimātaitai' is a Resilient River Communities project. Resilient River Communities is a joint initiative between Kānoa - the Regional Economic Development & Investment Unit, regional councils, and local authorities focused on developing and upgrading vital river management and flood protection schemes in Aotearoa New Zealand.

The initial bid for government funding in 2020 was based on replacement axial flow pumps and a modest pump house, estimated to cost $3.5 million. The original pump station design was unsuitable for the fish-friendly Archimedes screw pumps.

Design works for the upgraded pump station meant that the contract price for the pump station was $8.3 million, bringing the projected total construction cost, including the design and provision of the new pumps, to $11 million.

Council borrowed the required funds to ensure works could begin as scheduled, with initial plans to repay the debt over a minimum of 25 years.

Benefits

Increased protection for our homes, communities, and critical infrastructure
Project delivered with central government funding
Twenty-seven km of waterways that operate as the drainage network opened up to safe fish passage for indigenous species
Multi-collaborative effort to design and construct Mahi Toi elements in front of the new pump station building

Project update (16 August 2024)

Design for a new station to house the pumps completed and works contracted September 2022
New pumps designed, built and delivered to Invercargill September 2022
Whakawātea/cultural blessing to mark the beginning of the construction of the new pump station with Fulton Hogan on site from October 2022
Drain realignment and fish salvage operation undertaken November 2022
Pump station foundations: first pour completed February 2022; sheet piling cofferdam and foundation slab completed March 2022
Supervisory Control and Data Acquisition (SCADA) design and coordination underway with Environment Southland IT installing the required components to support the InfoSCADA infrastructure
Concept plans for Mahi Toi (cultural narrative artwork) presented to Council May 2023
Concrete pump house walls completed
Laying of the outlet pipes from the new pump station building to Koretī New River Estuary completed early September 2023
Construction of concrete viewing platform wall over the outlet pipes, asphalting and re-opening of the adjacent shared pathway early October 2023
Road resurfaced with two lanes of traffic reinstated early October 2023
Concrete cutting at the pump station to lower localised areas of the supports for the new pumps underway 7 October 2023
Chorus fibre installed November 2023
Viewing platform access hatch installed, November 2023, and light fittings December 2023
Fulton Hogan completed remedial works, including concrete pours to lower the height of the pump supports to the required level February 2024
Twin Archimedes screw pumps transported to Stead St site 20 March and installed 5 April 2024
Work commenced on inlet bays, which connect the drain network to the pump station
Transformer platform slab constructed and transformer installed, May 2024
Control room cladding and roofing completed and windows and fire doors installed, May 2024
Switchboards and electrical controls installed in weathertight control room, May 2024
Measure-up and installation of stairs, landings and handrails around control room completed May 2024
Contracts underway for Mahi Toi cultural narrative artwork components and foundations installed May 2024
Tuna/eel monitoring programme developed and custom tuna nets constructed
Building drainage and concrete slab installation between pump station building and Stead Street underway, July 2024
Dry and wet commissioning activities under a range of tide and inlet conditions to demonstrate the full operation of the pump station; dry commissioning completed July 2024, and wet commissioning underway
Fabrication and installation of Mahi Toi cultural narrative artwork, enhancing the pump station's exterior and viewing platform
Operational staff training and handover in the lead-up to practical completion underway
Practical completion date for the new pump station, 30 July 2024
Gifting of name 'Te Kupeka o Waimātaitai’ and official opening, 16 August 2024

Next steps

Completion and installation of Mahi Toi cultural narrative artwork and blessing - Nov 2024
Decommissioning of old pump station - Q2 2025
Tuna/eel monitoring programme

May 2020	Government announces $25 million funding for “shovel ready” climate resilience projects. Environment Southland receives a funding contribution towards replacement axial flow pumps and a new modest pump house at an estimated cost of $3.5 million.
September 2020	The National Policy Statement for Freshwater 2020 comes into force with a requirement for the provision of safe fish passage.
October 2020	Southlanders are invited to submit on a proposed co-funding arrangement where the Government funds 75% or $13.875m of their climate resilience projects and Environment Southland funds 25% or $4.625m. Because the Government’s funding was unexpected, the Council plans to use existing reserves of up to $1.5 million for these projects in the 2020-21 year and consult on funding the remainder of its contribution, up to $3.125 million, as part of the 2021-2031 Long-term Plan—total ES contribution $4.625 million.
April - May 2021	Council consults on a 25% contribution of $4.8m to the climate resilience projects (versus the initial $4.625m) with a plan to borrow the money to complete these projects over the next two years.
July 2021	Environment Southland announces the order of two Archimedes screw pumps designed to provide safe fish passage. The design of the new pump station needs to accommodate these large new-generation pumps. Long Term Plan adopted. Chairman Nicol Horrell notes that “the major increase in work stems from community expectations and central government requirements in relation to freshwater and climate change”. Also, for the Climate Resilience Projects Local Share Funding (Shovel Ready Projects), the plan states, “For the duration of the LTP we have budgeted to initially fund the climate resilience projects from debt. Investment in climate resilience projects in the 2021 financial year of $388,000 was funded from appropriate reserves. As the circumstances of each catchment in the project are different, final funding options will be considered after the completion of each project.”
August 2021	Council agrees to contribute $5.125 million to the climate resilience projects in a co-funding arrangement with Kānoa following 2020-21 community consultation.
September 2021	Concept plans for news pump station shared with Council.
December 2021	Kānoa representatives Regional Economic and Development Unit investment director Eliot Linforth-Hall and climate resilience project advisory board chair Basil Chamberlain visit the Stead Street pump station site and meet with project staff while also inspecting progress with the ICC Stead Street climate resilience project.
January 2022	Presentation to Council about designs for the new Pump Station and projected budget increase.
June 2022	Annual Plan approved. Council highlights the following change from the Long Term Plan in the previous year: “a review of the climate resilience projects, which has been built into the budget to provide to provide for potential increased costs given cost increases being seen in the national construction sector.”
September 2022	Contract for Stead St Pump Station replacement signed with Fulton Hogan. The contract price for the pump station is $8.3 million, bringing the projected total construction cost, including design and provision of twin Archimedes screw pumps, to $11 million. This is an increase of $4.5 million above the projected cost of $6.5 million in the 2021/22 Annual Plan.
October 2022	Construction underway.
August 2023	An update given on the Stead Street Pump Station climate resilience project to the Finance and Performance Committee, and a press release issued regarding the floor height and height of pump supports within the pump station.
September 2023	Environment Southland and its design consultant and contractor agree to a solution regarding the design and construction issues with the Stead Street Pump Station. Environment Southland seeks advice on recovering the cost of the remedial solution from the parties involved and is not expecting an increase in the project budget.
March 2024	Remedial works completed and construction of the pump house underway.
April 2024	Twin Archimedes screw pumps installed.
April 2024	Council is advised that the new facility's indicative commissioning date will be mid-to-late June 2024. The remedial works took longer than anticipated, primarily due to the significant hydro demolition required to prevent damage to the existing reinforcing and maintain the building's structural integrity.
May 2024	Indicative commissioning date re-scheduled for mid-to-late July 2024 due to wet weather delaying electrical installation, which requires a watertight building envelope.
July 2024	Contract completion date for the new pump station is confirmed for late July 2024.

Stead Street pump station replacement

Share this

Share this page