Environment
Environment Southland today signed a contract with Fulton Hogan to initiate the replacement of the Stead Street Pump Station.
Environment Southland chief executive Wilma Falconer said the contract would provide the City of Invercargill-Waihōpai, Lake Hawkins residents and the Invercargill airport with protection from inundation for the next 50 years.
“The existing building and pumps are now at the end of their life and there is increased risk of failure. 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,” Wilma Falconer said.
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 contract price for the pump station is $8.3 million and brings the projected total cost of construction, including design and provision of fish-friendly Archimedes screw pumps, to a total of $11 million. This is an increase in cost of $4.5 million above the projected cost of $6.5 million in the 2021/22 Annual Plan.
The initial bid for government funding in 2020 was based on replacement axial flow pumps and a modest pump house at an estimated cost of $3.5 million. The introduction of the National Environmental Standards for Freshwater later that year meant that the initial pump specification would not meet the Standards’ requirements to provide fish-friendly passage between the pump station site and New River Estuary.
New Archimedes screw pumps were ordered from the Netherlands in 2021. In addition to allowing safe fish passage through the drainage network, these pumps also increase pumping capacity by 40% compared to the original specification to meet anticipated sea level rise and flooding in the area over the next 50 years.
The original pump station design was not suitable to accommodate these new generation pumps. Design works during late 2021 and early 2022 identified project costs to build a new pump station on the site at $6.5 million. This was budgeted in the council’s 2022/23 Annual Plan.
Council went to tender in the middle of this year to advance the project. Further engineering assessment requiring preparatory groundworks on the site and cost increases associated with the Ukraine war, inflation, a heated construction market and labour market constraints, resulted in a projected project cost of $11 million; $4.5 million above the assessment at the time the 2022/23 Annual Plan went to print.
Council will borrow the required funds to ensure works can begin immediately, with initial plans to repay debt over a minimum of 25 years. Council is investigating options for increased third-party funding to ensure ratepayer contribution is minimised. There are no plans to increase rates until the project is completed, final costs are known and third-party funding streams identified. The duration of the project is expected to be 18 months and there will be public consultation before June 2024 to establish how debt repayment will be managed over the life of the asset.
The new pump house will be constructed on Stead Street alongside the existing pump station, which will remain operational until the new pumps have been fully commissioned in mid-2023. There is no intention for permanent road closures on Stead Street throughout the duration of the project.