Last update: 11 March 2024
Why do you need to replace both bridges?
We will be replacing Hikuwai No. 1 and No. 2 bridges. No. 1 will need to be rebuilt as the Bailey bridge is only a temporary solution. Both bridges are packaged together as they are very close to each other and need to have the same height. Therefore, No. 2 will need to be replaced at the same time to build a resilient solution.
The vulnerability of the site is why we need to deliver the project as quickly as possible. Bailey bridges are a short-term solution and there is high probability a flooding event would cause extensive damage to the bridge and make the road unpassable.
How are you building the bridges to be more resilient?
The bridges will be about two and a half metres higher to allow flood waters to pass underneath them.
The new piers are designed in a way that provides stronger resilience to extreme weather and earthquakes. The piers will be:
- placed further apart to avoid slash getting trapped between the two piers
- rounded to prevent slash getting hooked on a corner
- set on piles which will provide additional strength against collapse. This will also help protect against earthquakes.
How long does it take to build the Bailey bridge?
Approximately three months.
How long will the road between the two Bailey bridges (i.e. the temporary realignment) be?
Approximately 100-200m.
Are you going to raise the road too?
As the bridges are being raised by about two and a half metres, the road will also have to be raised to this level. As a result, there will be an embankment in between the two bridges. We are building up the low ground with earth and gravel to carry the road between the bridges. We have checked the flood modelling for this area and raising the road will not have an impact on flooding. The raised embankments will not create a barrier that makes the flooding worse.
Are you improving the intersection with Matairau Road?
The intersection with Matairau Road is included in our work. We are ensuring that the Matairau Road joins SH35 at the same elevation. We are designing a safer intersection here including wider curves to allow for easier truck turning movements and ensuring there is adequate site distance from Matairau Road when turning onto the highway.
When will you inform people about the progress of the project?
We will be visiting Tokomaru Bay and Tolaga Bay communities again via a number of drop in sessions along the Coast in April 2024. We will ensure that the public is kept up to date via Facebook, the project webpage, newsletters and media releases. People can always get in touch with us if they have questions or concerns.
When will you start construction and how long will the project take?
Construction will start in March 2024 and TREC is aiming to open both bridges by Christmas 2024. You may notice that the road will settle a little bit over time, and you may occasionally see maintenance crews adding a layer to the road for about a year after the bridges have been completed.
How will you fund the rebuild and upgrade of the bridges?
The rebuild will be covered by the funding already allocated to cyclone recovery works.
The Hikuwai No. 1 bridge was destroyed by forestry slash. Is something being done to address that so that it won’t happen again?
The preferred solution for Hikuwai Bridge No1 and No2 will make the bridges more resilient to debris and slash. The bridges will be about two and a half metres higher to allow flood waters to pass underneath the bridges. The piers will be placed further apart to avoid slash getting trapped between the two piers and they will also be rounded to prevent slash getting hooked on a corner. The piers will also be set on piles which will provide additional strength against collapse. This way we can ensure the new assets are protected and withstand future weather (and earthquake) events. The TREC team is in ongoing conversations with Gisborne District Council and the Ministry for the Environment to address forestry slash and the damage caused by it. However, managing forestry slash is not within the scope of this project (or within the wider TREC scope).
