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Flaxmill & Wanstead Roading Upgrade

Central Hawke’s Bay District Council, with funding from the Provincial Growth Fund are improving transport infrastructure for the communities along Porangahau and Wimbledon roads. A key focus of the programme of work is the bridge at Flaxmill.

Flaxmill Bridge has a history of flooding. Rainfall events in February 2004 and March 2018 cut electricity supplies and compromised community safety. In 2018 the road either side of Flaxmill Bridge was closed in excess of 20 days due to flooding.


With growing volumes of freight using the route, reliability and resilience needs to be assured if the regional economy is to be protected and opportunities for productivity are enhanced. The conclusion of this project will provide future generations with safe and durable roading infrastructure along what is a key thoroughfare in our district.

This project has been awarded to Russell Roads who started on site on Monday 29th March 2021. Watch the project blessing and project commencement bellow: 

Construction Staging:

Road sites split into three:

  • 1st section is immediately north of the Flaxmill Bridge to the first corner. A 600mm lift. Construction programmed March-May 2021
  • 2nd section is between section 1 and 3 and is located on the tight radius corner in the dip, An 800mm lift. Construction programmed August 2021-June 2022
  • 3rd Section is south of Wanstead Bridge to just north of Hiranui Road, An 800mm lift. Construction programmed August 2021-June 2022.




  • One lane of traffic to be maintained at all times, temporary traffic control will be in place.
  • Lift will be completed in layers across the full width of the road, laying new pavement material on one side, compacting it in about 150mm lifts and then doing the other side of the road.
  • New chipseal surfacing
  • Some temporary fencing


  • Local cut to waste sites
  • Employing local resources

Ugly Hill culverts will be also upgraded to mitigate flooding along that section of the road as part of the works, August 2021- June 2022.

If funding allows, silt removal from approximately 400m upstream of Flaxmill bridge to approximately 1.6km downstream. Approximately 40,000m3 of material to be removed, timeline for this would be August 2021- June 2022.

Flaxmill / Wanstead Roading Upgrade – Stage 2

Work is underway on Stage 2 of the Flaxmill, where clearing works are underway, as well as installation of new culverts and drainage prior to milling and preparing to lift the section of road, Stage 2 and 3 see the road lifted by approx. 800mm to improve resilience and flooding risk.

Flaxmill Stage 2 Prep

Separable Portion 1 is now complete. This is the first of five sections in this project - keep an eye on our updates to follow the next sections in this programme of work. 

 IMG 4890

Works are progressing well with the road lift as part of Stage 1 just north of Flaxmill Bridge, the road has been milled back preparing to have the additional fill added in to lift the road in stages – progressing as planned and on track to be completed by the end of May.

C1097 Flaxmill Progress 30.04.21

The Flaxmill and Wanstead Road Upgrade project is also progressing well, with most of the clearing work done and the installation of a subsoil drain underway. This week the team at Russell Roads will be continuing to work on shoulder widening and the installation of a subsoil drain.



On March 29th, we held the blessing to commence the Flaxmill Roading Upgrade around Flaxmill bridge and north to Wanstead bridge. Our contractor Russell Roads is establishing onsite this week to lift the road as the first of five separable portions. The blessing was led by local hapu Ngati Kere, and was well attended by local landowners, CHBDC councillors, staff, our design team Stantec, our contractor Russell Roads and our funder the Provincial Development Unit. A pretty exciting moment in the programme to get our flagship project underway!

Hydraulic modelling identifies that Porangahau Rd has a <2year LOS, with the lowest levels being along a 1300m length adjacent to Wanstead Swamp wetland.

An engineering options assessment indicates that a 10 year LOS is achievable within the funding and timeframe constraints of the PGF, and a further lift to a 75 year LOS is considered feasible if a longer timeframe is available and funding outside the PGF is obtained.

Therefore, the preferred option strategy is:

  • Online road raising: raise the road embankment level between Wanstead Bridge and Flaxmill Bridge to a 10 year LOS, with associated improvements to Flaxmill Bridge and Ugly Hill Corner culverts, using PGF funding and taking advantage of a scope of work that is online within the road reserve and likely to have a straightforward consenting process. The cost estimate for the works is $8.2M.
  • Future online and offline works: begin planning (including consultation) for associated future online and offline works that would further raise the LOS to 75 years capacity for an additional budget cost of $3.3M. This offline work is mainly stream and channel widening through private land and provides improvement works to offset future projected climate change impacts.

You can read our report on the Flaxmill Inundation project here.

flaxmill bridge



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