GDC keeps flood scheme budget despite costs hike

A109 Light Utility Helicopter flight with mayor Gisborne City from the air in November 2023.

GISBORNE District Council is not changing its budgeted spending for the Waipaoa Flood Control Scheme upgrade, despite being faced with a big shortfall in the proposed budget for the project.

The Future Tairawhiti committee of all councillors has resolved to leave the budget in the 2018/28 Long-Term Plan (LTP) unchanged.

It adopted a recommendation to re-evaluate and refine the budget requirements as part of the 2021/31 LTP.

The scheme is being upgraded to meet a 100-year design storm, based on climate change modelling out to 2090.

The existing budget calls for expenditure of $16 million over the LTP then $4.3m in the following two years, but the project has now been estimated to be within the range of $30m to $35m.

Councillors were told in a report that the original estimates excluded project management costs and inflation, which increased the cost to $24m.

After further modelling and peer-review, the design height for raising the 64 kilometres of stopbanks has been increased in the order of 1.8 metres, compared to the original 1 metre indicated — adding $6m to $11m to the cost.

The inclusion of a cycleway/walkway on top of the stopbanks would cost $3m more, however it has not been included in the revised project costs and would need to be funded externally.

The council has a joint application with four other regional councils to the Provincial Growth Fund for $6m towards the cost of the project.

The council has been granted resource consent for the proposed improvement work to the stopbanks by a hearings commissioner, but an application for the cycleway/walkway was refused.

The council’s lifelines director David Wilson said tenders had been called and the council was waiting for them to come back for year one, so work could start this construction season.

Construction would be done in a three-month period in the summer, the low-flow period for the river.

Graeme Thomson wondered if the council should move the funding to the first three years of the 10-year plan. The council would know by then if it had the grant funding.

“Let’s hope we do get that funding,” he said.

Brian Wilson said there would be few other areas in the country where flooding would have such an impact as on the Poverty Bay Flats.