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 rural network was further impacted by heavy rain in June (the third state of emergency for the district in 2023) causing more significant land movement.
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 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.
Initial clean up
$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.
Budget for 3 years 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
S1: Repair or replacement of 61 bridges
Costs estimated at $140-160M to repair back to normal. Or $255-$320M if we add resilience (revised cost)
All this bridge work could take up to 4 years.
Post Gabrielle, we assessed all 424 bridges in our region and found 61 were either destroyed or had major issues. Staff and contractors repaired 140 bridge faults including removing wood debris and structural fixes within 4 months of Gabrielle.
8 bridges destroyed - categorised as 'Black' serious damage
We're working with NZTA Waka Kotahi on major roading infrastructure replacement. We need to submit a benefits and economic evaluation on each destroyed bridge. This involves looking at alternative options, traffic volumes, detailing benefits of the project and economic costings.
If the evaluations are favourable and we can secure government funding, then the next challenge will be obtaining the remaining costs from ratepayers.
Design, investigation and procurement processes will take at least 12-16 months, then we would have a rolling programme of 2-3 bridges a year, depending on funding. Geotechnical investigations underway at all sites.
Residents have asked about bailey bridges, these are prioritised on a nationwide basis including state highways.
To construct a new bridge could take up to 3-4 years.
| Bridge and road | Comment | Status |
|---|---|---|
| Burgess Bridge, Burgess Rd | Ford crossing (river level dependent) is in place. A new bridge is subject to funding, but not likely until summer 2028. | Restrictions |
| Hangaroa Bridge, Hangaroa Rd | Temporary engineered crossing installed, local access only. A new bridge is subject to funding, but not likely until summer 2028. | Restrictions |
| Hollywood Bridge, Bushy Knoll Rd | Bailey Bridge installed, minor enhancement works for future resilience. Work planned to start July 2024. | Open |
| Grays Bridge, Bruce Rd | Temporary box culvert installed to provide low level crossing access. A new bridge is subject to funding, but not likely until summer 2026. | Restrictions |
| Mangatai Bridge, Te Kowhai Rd | Ford crossing installed. A new bridge is subject to funding, but not likely until summer 2028. | Restrictions |
| Mata Bridge (Huiarua), Upper Mata Rd | Geotech investigations completed, design optioneering underway. A new bridge is subject to funding, but not likely until summer 2027 | Alternative route via Tuakau & Ihungia roads |
| Pauariki Bridge, Hikuwai Rd | Ford crossing installed. A new bridge is subject to funding, but not likely until summer 2028 | Restrictions |
| St Leger Bridge, Ruakaka Rd | Alternative access via Ruakaka Rd. Design optioneering underway. A new bridge is subject to funding, but not likely until summer 2026 | Restrictions to 3.5T on wet days |
| Updated August - 6.6% of the overall project is completed. |
10 bridges with major structural issues - 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 | Work on approach road to start late 2024. | Open to all traffic |
| Waitangi Bridge | Designs underway | Restrictions in place |
| Updated August - 48% of red and orange bridges are completed |
43 bridges with major scouring - 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 July 2024 |
Construction is currently underway on Whakauranga Stream Bridge on West Ho Rd.
Updated August - 48% of 'red' and 'orange' bridges are completed.
S2: 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
S3: Drop outs and retaining wall repairs
Costs estimated at $80M-$105M. Or if we add resilience $120 - $255M
Work could take up to 2-3 years to fully complete.
We estimate there's over 250 major drop outs or sections of roads impacted by river erosion across the entire network.
These sites will have signs and road cones to make them safe until we can get engineers and geotechnical assessments completed. Initial site assessments could be completed by August 2023. The more complex issues may not be completed until the end of October 2023.
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
S4: 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.
S5: 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.
