Three concrete floodwalls on the Rangitāiki River are being replaced to ensure they continue to help protect our communities from flooding in the coming decades.

During the 2017 flooding event, excessive seepage (the slow escape of water through porous material) was observed at three floodwalls downstream of the College Road breach site. While controlled seepage is good for relieving pressure within the stopbanks, excessive seepage can lead to stopbanks collapsing putting people and properties at risk.

Investigations into the excessive seepage, along with a recommendation from the Rangitāiki River Scheme Review, has led to the need to upgrade the existing floodwalls adjacent to Greig Road, Thornton School and College Road with new flood defences.

rangitaiki floodwalls map

The new flood defences are a combination of sheet piles (big sections of sheet steel that have interlocking edges that are driven into the ground) that are then covered by an earth stopbank. This combination ensures that any seepage is controlled and will not undermine the stopbank.

This project will involve the following at each of the sites:

  • Excavation and removal of the concrete floodwall.
  • Installation of a sheetpile wall, at the location of the concrete floodwall.
  • Placing of selected earthfill against the sheetpile walls and at each end of the sheetpile walls to control seepage.

Greig Road: These works were completed in April 2021.
Thornton School:These works got underway in early July 2021 and are expected to be completed by October 2021.
College Road: These works are expected to commence in January 2022 and be completed by May 2022.

Crown Infrastructure Partners funding

Bay of Plenty Regional Council has received funding from Central Government’s Crown Infrastructure Funding for the floodwalls.

Toi Moana put the project up as a shovel ready project after Central Government announced it wanted to help with economic recovery after Covid 19.

The funding covers $2.25 million of the $5.0 million project.

This was one of six projects Bay of Plenty Regional council received funding for

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PROJECT CREATED

06 Nov 2021

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Project Updates

29 days ago

Thornton School Floodwall upgrade begins

Work has started on replacing the floodwall on the Rangitāiki River near Thornton School.

The new flood defences are a combination of sheet piles (big sections of sheet steel that have interlocking edges that are driven into the ground) that are then covered by an earth stopbank.

Thornton School Floodwall upgrade begins

Work has started on replacing the floodwall on the Rangitāiki River near Thornton School.

The new flood defences are a combination of sheet piles (big sections of sheet steel that have interlocking edges that are driven into the ground) that are then covered by an earth stopbank.

The upgrade is designed to control excessive seepage - that is the slow escape of water through porous material - which can undermine and collapse the stopbank during a flood event.

This is one of three floodwalls on the Rangitāiki River with funding assistance from central government’s Crown Infrastructure Funding project.

The upgrade of the Greig Road stopbank has been completed and at the College Road site we have had initial conversations with directly-affected landowners.

2 months ago

Upgrade of the Greig Road stopbank completed

The upgrade of the Greig Road stopbank on the Rangitāiki River has been completed. The new earth stopbank with a sheet-pile centre is designed to control seepage.

Upgrade of the Greig Road stopbank completed

The upgrade of the Greig Road stopbank on the Rangitāiki River has been completed.

The new earth stopbank with a sheet-pile centre is designed to control seepage - that is the slow escape of water through porous material which can undermine and collapse the stopbank and put people and properties at risk.

This site in numbers:

  • 230m of stopbank constructed
  • 235 sheet piles used
  • 5000 tonnes of earth fill used
  • 9 contractors
  • Took nearly 3000 hours to complete

This is one of three floodwalls on the Rangitāiki River that Bay of Plenty Regional Council received money from Central Government’s Crown Infrastructure Funding project to help cover the cost of the work.

The Thornton School floodwall is expected to begin construction later this month, and at the College Road site final design is progressing and the first stage of talking with directly affected landowners has been completed.

stopbank
10 months ago

Update: 16 October 2020

The commencement of flood protection projects on the lower Rangitāiki has signalled the start of the 2020 construction season for the Bay of Plenty Regional Council engineering team.

Update: 16 October 2020

The commencement of flood protection projects on the lower Rangitāiki has signalled the start of the 2020 construction season for the Bay of Plenty Regional Council engineering team.

Work is underway to replace a 300-metre section of flood wall on Greig Road, with Waiotahi Contractors making good progress on what is expected to be a four-month construction process. Investigations on the floodwall were carried out after the April 2017 flood which has led to the design of the new earth stopbank with a sheet-pile centre.

Engineering Team Leader Peter Hay says that during the construction period, that section of West Bank Road will be reduced to one lane controlled by a traffic light and Council and contractors thank road users for their continued patience.

“Designs are being finalised for the replacement of another section of Rangitāiki River floodwall on East Bank Road, near the Thornton School and work is progressing on concept designs to be shared with owners of properties adjoining the remaining flood walls on College Road, Edgecumbe,” Mr Hay adds.

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