Our local roading network suffered significant damage in 2023. Almost all rural roads were closed during cyclones Hale and Gabrielle with communities cut off for weeks with 8 bridges destroyed, 54 with major damage, significant slips and dropouts leaving a bill stretching into the hundreds of millions of dollars.
The total damage to our local network has been assessed as $465 million to get it back to where we were, but to build back stronger we need $725 million. We've received a support package from government of 125 million, with an additional $85 million for the initial emergency response costs.
Our focus is always to reopen roads to residents who are cut off and to get access for heavy freight to support our rural communities. Priority is given to school bus routes, safe access to connect communities and forestry and farm access routes for animal welfare.
$85m was spent opening or providing temporary access for disconnected communities.
This included alternative access like temporary bridge repairs, ford crossings, using private land for road access and state highway detours.
It also included clearing slips, removing slash from under bridges, silt clearing, roadside drainage works and tree removal.
Our 3 year plan budget 2024 - 2027
$125 million government funding to help establish bridges across the region, fix Tiniroto Road and address slips and dropouts. We've started these projects and expect to spend $85 million over the next 3 years. The remainder of funds will be spent post 2027. We're planning some additional work with funding from NZTA if available, and have allocated up to $105 million in our Three Year Plan for extra recovery efforts.
Our 6 project work streams
- $23m on destroyed bridges - we'll fix 4 bridges with the government funding.
- $17.5m on damaged bridges - 41 out of 51 severely damaged bridges will be repaired.
- $1m - replacing safety guardrails on bridges
- $45m Tiniroto Road - assessing an alternative to SH2 south and addressing risks at the bluffs.
- $8m to fix major slips and dropouts
- $27m working in partnership with iwi on projects to provide greater resilience to communities
Bridge repairs or replacement
We assessed all 424 bridges in our region following Cyclone Gabrielle:
- 64 bridges were either destroyed or required significant repairs.
- 35 bridges required minor repairs to ensure their resilience in future severe weather events.
- 32 bridges were also damaged in severe weather events prior to, or post Cyclone Gabrielle
Within 4 months of Cyclone Gabrielle, 140 bridge faults were repaired including removing large wood debris and structural fixes.
8 bridges destroyed - categorised as 'Black' serious damage
Each bridge has a project status, funding and current alternative access.
Project outcome
Replacement of this bridge did not meet NZTA's funding criteria. It won’t be considered for replacement now or in the future.
Alternative access
A low level ford crossing is in place. The crossing is river level dependent.
Project outcome
Replacement of this bridge did not meet NZTA's funding criteria.
Changes in land use have negated the need for the Hangaroa Bridge replacement. A new bridge is still under consideration as part of the Tiniroto Road realignment past the Hangaroa Bluffs.
Alternative access
A temporary engineered crossing has been installed for locals access only.
Project status - completed
The new Hollywood Bridge is a wide single-lane bailey bridge that spans the Hangaroa River and has reconnected a community.
It was initially a temporary solution. Following a comprehensive feasibility analysis, it's now the permanent solution.
The bailey bridge was designed and constructed to a height 2m above the height of the old bridge and offers improved flood and earthquake resilience compared to the previous bridge.
In September 2024, strengthening work was carried out on the bridge to extend its service life to 50 years.
While a new permanent bridge would offer some improvements such as lifting speed restrictions, extending the life of the bailey bridge is a cost-effective solution at this time.
Funding
The cost of $3.2 million was 100 percent funded by the $68m from NZTA's initial cyclone-damaged road network funding.
Project stage
Optioneering - evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
Funding
Following guidance from NZTA in September 2024, further economic assessment is required before a funding outcome can be given.
Replacement of this bridge may not be economically viable as it serves a remote area.
Alternative access
A temporary box culvert has been installed to provide low level river crossing. Access is river level dependent.
Project stage
Optioneering - evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
Funding
Replacement of this bridge did not meet NZTA's funding criteria and won’t be considered for replacement now or in the future. However, NZTA has endorsed investigation into an alternative access road. We've started the investigation.
Alternative access
A low level ford crossing in place. Access is river level dependent.
Project status
Optioneering - this phase is about evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
Funding
A replacement bridge is very likely to receive funding due to its economic justification. Awaiting final design and cost approvals.
Expected completion date
A new bridge is subject to funding, but not likely until early 2027.
Alternative access
Alternative route via Tuakau and Ihungia roads.
Project stage
Optioneering - evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
Funding
Further economic assessment is required before a funding outcome can be given by NZTA.
Replacement of this bridge may not be economically viable as it serves a remote area.
Alternative access
A low level ford crossing is in place. Access is river level dependent.
Project stage
Optioneering - evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
Funding
Due to its economic justification, a replacement bridge is very likely to receive funding. Awaiting final design and cost approvals.
Expected completion date
A new bridge is subject to funding, but not likely until the end of 2026.
Alternative access
Alternative access via Ruakaka Road. Restricted to 3.5T on wet days.
Project status descriptions
Each stage of the project is crucial to ensure a bridge is built or repaired safely, efficiently and to the required specifications.
- Site Inspection: This initial step involves assessing the bridge for damage and determining if a restriction needs to be put in place until the permanent repair is completed. This can involve restricting the bridge to light traffic only up to full closure. The assessment then captures the faults with the bridge and surrounding retaining walls. This also involves taking lots of photos of the site for analysis of past inspection.
- Optioneering: This phase is about evaluating the faults and producing different construction repair options, considering risk and safety aspects to choose the most suitable repair option that ensures maximum safety and structural integrity.
- Detailed Design: This stage involves turning the initial concept into a complete project design package. It includes site testing of materials and ground conditions. This information is then used to produce the construction drawings and tender documents.
- Tendering: The tendering process involves inviting contractors to bid on the repair, providing a price repair methodology and other key information.
- Construction: This phase covers the actual building or repair of a bridge. For a new build this will start from site preparation, foundation construction and beam placement to the completion of the structure.
Repairs can range from hand rail repair to replacing structural components of a bridge.
- Handover: the bridge can be opened for public use.
Construction is completed, the bridge is inspected any outstanding works are rectified and final inspections are carried out. Then the bridge along with all relevant documentation is formally handed over by the contractor to Council.
- Completed: The completed bridge undergoes regular inspections and maintenance by Council.
10 bridges categorised as 'Red' significant damage
These bridges require immediate repairs, due to the risk we could lose them completely in a further flood event.
Repairs have been completed on Arakihi Bridge, Carlson Bridge on Waikura Rd, Littleworth Bridge on Pehiri Rd, Mangareia Bridge on Walker Rd, Whakoau Bridge on Mata Rd, Awatere Bridge on East Cape Road.
| Bridge and road | Comment | Status now |
|---|---|---|
| Makarika #2 Bridge | Bailey bridge installed. Abutment fix programmed for late 2024. | Open up to 50 Tonnes |
|
Mangaheia #4 Bridge Tauwhareparae Rd | Bailey bridge installed. | Road beyond remains closed. |
| Waikereu Bridge, Riverside Rd | Repair work underway | Closed from 11 Nov |
| Waitangi Bridge | Designs underway | Restrictions in place |
| Updated August - 48% completed |
43 bridges categorised as 'Orange' moderate damage
With major scouring around the abutments, work is needed before they become bigger structural issues.
There are 20 bridges in the Waipaoa area, 17 in Uawa and 6 in the Hikurangi area.
Repairs to 16 bridges have been completed
| Avondale Bridge on Tinroto Rd | Kie Kie Bridge on Kie Kie Rd | Lytton Rd box culvert |
| Makarika 1035 Bridge on Golfcourse Rd | Martins Bridge on Utting Rd | McCreadies Bridge on Wharekopae Rd |
| McCarthy’s Bridge on Matokitoki Valley Rd | McNabs Bridge on Arakihi Rd | Oliver Bridge on Oliver Rd |
| Walkers Bridge on Mangaoporo Rd | Arakihi Bridge on Arakihi Rd | Davies Bridge on Taumata Rd |
| Hineroa Bridge on Tarewa Rd | Makarika Bridge on Ihungia Rd | Te Arai on Whareponga |
| Triple culvert on Waimata Valley Rd. | ||
| Updated August - 48% completed |
Construction is currently underway on Whakauranga Stream Bridge on West Ho Rd.
Tiniroto Road at the Hangaroa Bluffs
Costs estimated at $35 - $50M to repair back to normal. Or $65-$130M if we add resilience (revised cost)
We're looking at all options to fix this but a long term fix could be up to 3 years away,
The road suffered significant damage at the bluffs - 1400m of road was undermined with river protection works partly or fully destroyed. The 2 lane road was scoured away and reduced to less than one lane in parts. It required repairs to the retaining wall structures and rock protection works. The road had reopened to single lane access.
June 2023 rain event
After a helicopter fly over of the Hangaroa Bluffs on Tiniroto Road, engineers discovered tension cracks that could come down on the road without warning. Geotechnical engineers inspected the bluffs between the 35 - 37km mark. All 3 bluffs were found to present imminent and extreme risk to road users.
August 2023 - The section of road was closed as it was deemed to be unsafe, due to extreme injury or death as a probable consequence should road users be impacted by falling material.
17 June 2024 - after essential safety work was carried out at the Hangaroa bluffs, the road reopened after being closed for 10 months.
Tiniroto Bluffs reports
- June 2023 Tiniroto Road Site Inspection Report by LDE
- July 2023 Addendum to the Inspection Report - Risk Mitigation Options and Costs
Resilient solution for the road
For more information about the resilient solution for Tiniroto Road
Dropouts
Costs estimated at $80M-$105M. Or if we add resilience $120 - $255M
Work could take up to 2-3 years to fully complete.
The initial estimate following Cyclone Grabrielle was over 250 major dropouts or sections of roads impacted by river erosion across the entire network.
Dropout repairs are in progress.
- Tranche 1 & 2 - NZTA dropout repairs in progress. 14 of the 19 sites have been completed. 5 sites underway.
- Tranche 3 - NZTA dropout repairs in progress. 7 of the 43 sites have been completed.
- Tranche 4 - dropout repair application to NZTA
These sites will have signs and road cones will be replaced with semi-permanent markers at unattended worksites. Completing geotechnical investigations across multiple sites.
Waihau Road
In the June 2023, a significant landslide washed out part of Waihau Road approx 4.8km from the intersection with SH35. Geotechnical engineers inspected the site where 5m of the road had been lost. Their findings were that this was part of a much larger 110m fault.
The dropout was the direct result of a landslide and debris flow that occurred more than 30m above the road. The debris flow washed over the road and blocked the road drainage. As a result of the loss of drainage, the road was washed out by the flood and debris. Residents only had walking access around the slip.
Work to repair the dropout and reinstate road access was completed and reopened to residents in November 2023. Following a favourable risk assessment - the road reopened to all traffic from December, but with conditions.
No stopping signs are installed at both ends of the repaired section of road.
The following triggers have been put in place as the landslide could reactivate and the road may dropout.
Alerts for MetService heavy rain warnings that include this area:
- Orange Warning - residents and campers need to closely monitor the weather forecast and be prepared to evacuate.
- Red Warning - the road will close, residents and campers need to evacuate.
Waihau Road slip reports
7 December 2023 - Post-Slip Risk Assessment Report
27 July 2023 - Updated report - LDE Report on Waihau Road Slip
Silt removal
Cost estimated at $15-20M
It's estimated that there's over 650,000 cubic metres of silt to be removed from drains, slips and roads. This needs to be carted to a disposal sites once the sites are ready to take the material. In places the silt still needs to dry out before it can be removed.
Slash removal
Costs estimated at $130M
We've removed slash from 77 bridges at a cost of $1.7M.
Staff have scoped the cost to remove all the slash in the catchments where bridges have been destroyed or majorly impacted. The risk if this debris is not removed is it may compromise any future bridge repair wok.
Assessments are completed and procurement to remove and dispose of it is being developed.
Tauwhareparae Road
There are 4 damaged bridges, major slips and 2 landslides at the 17 and 26km mark - staff are working on the full business case for Tauwhareparae Road to be able to apply for funding. This could take up to 6 months and will also include options for alternative routes.
Landslide dam update 28 August - the landslide dam on Tauwhareparae Road has been assessed as low to minimal risk of failure. The dam of water is being actively monitored and inspected, especially after rain. The landslide dam is quite small at 1.2ha and water is freely flowing through it which reduces risk. The gradient on the dam is low, which also reduces the risk of rapid failure. The dam has been assessed as having 26,000m3 of water in it and measures 5m deep and 20m wide.
