The Ashburton District Council is set to pursue the government to help fund a ‘nationally significant’ $113.6 million second bridge project between Ashburton and Tinwald, after reviewing a detailed business case for investment.

Chief Executive Hamish Riach says, “This is a rigorous and thorough business case which places Council in a strong position to seek funding from the government. It positions Ashburton-Tinwald connectivity as more than just a second bridge for the township, but as a solution for enhancing State Highway One – the spine of New Zealand”.

“Now that more detail has been outlined, we have a clear view of the costs as well as the benefits. The revised project cost reflects the ongoing increases in construction costs since the initial estimate for the bridge construction was made over ten years ago,” Mr Riach said.

In 2021, Council budgeted $7.5 million of debt and funding in its 2021-31 Long Term Plan for the conceptual project when the initial estimate was $37 million. In light of the detailed business case, and the significant increase in construction costs, Council will consider increasing its own contribution in the next Annual Plan process 2023/24.

Once funding is secured, the detailed engineering design is proposed for 2024/25 with construction planned to begin the following year.

Mr Riach says that the business case demonstrates that the constraints of having only a single connection goes beyond just traffic congestion issues. It shows that travel choice, resilience, community severance, safety and freight movement across the Ashburton Hakatere River are significant issues.

The report noted the economic and social impacts of the bridge closure in May 2021 due to severe flooding, which Mr Riach says highlights the role the bridge could play in climate change resilience.

“In May 2021 we saw how the increasing frequency of extreme weather events from climate change is likely to affect communities into the future with the bridge closure. It not only physically divided our community, but it also had serious impacts on the South Island, such as affecting goods being delivered to Dunedin”, said Mr Riach.

The report shows that the current Ashburton Bridge has risks that are unique to other similar bridges, such as high usage by its local community and a very long detour route.

The business case unveils detailed concepts to link Chalmers Avenue in Hampstead with Grahams Road in Tinwald. The proposal includes a 360-metre long bridge for vehicles, walkers and cyclists across the Ashburton/Hakatere River, a 60-metre long bridge in the Tinwald flood plain and new roundabouts at South Street, Wilkins Road and Grahams Road intersections.