Western Hills Sewer Main Rehabilitation
On behalf of Hutt City Council and Upper Hutt City Council, we are working on a project to line the wastewater pipeline on State Highway 2 crossing north of Melling to strengthen the resilience of the network.
If you have any questions about this work, please contact:
Wellington Water, 04 912 4400
Latest Updates
One manhole reinstatement to go, partial removal of traffic management will start on Saturday night.
Reinstatement is well underway with three manholes set yesterday and the road around them resurfaced.
The final of the four liners was been successfully cured overnight. Reinstatement around manholes to be completed today.
Critical works to line a section of a wastewater pipeline running underneath SH2 north of Melling, between Block Road and Pomare Road starts soon.
Work is expected to start on the 12 April 2025, aligning with the Easter school holidays, when traffic volumes are generally lower, to minimise impacts on road users. The works will be carried out 24/7 and are anticipated to take two weeks. During this time, daily updates will be provided on Wellington Water’s website and social media platforms.
To ensure the safety of the workers and road users, traffic management will be in place from Melling Link and Kennedy Good Bridge. One northbound lane will be closed and speed limits will be reduced.
When heading north towards Lower Hutt and Upper Hutt:
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To balance the impacts on both lanes and surrounding local roads, one of two southbound lanes will be converted into a northbound lane within the work zone during this time.
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To access Western Hills, use the left lane onto Harbour View Road and Tirohanga Road as usual. However, you can only exit using Harbour View Road.
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If heading to Hutt Central, use Melling Link instead of Block Road to turn right. Block Road will be closed to all traffic except buses and emergency services.
When heading south towards Wellington City:
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Use the left lane to stay on SH2 South.
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To access Western Hills, use Harbour View Road instead of Tirohanga Road, as there is no right turn at the Tirohanga / Block Road intersection.
This traffic layout has been chosen because the morning peak traffic is more spread out and there are more easily accessible alternative routes for the southbound travelling public. The layout and spacing of the intersections also make managing southbound traffic queues easier.
This work is weather dependent, and regular updates will be provided.
The Western Hills Main Sewer Rehabilitation Project aims to line a section of a wastewater pipeline on State Highway 2 (SH2) that is in poor condition and critical to the Hutt Valley wastewater system. The project area is located between Block Road and Pomare Road near Melling Link Bridge.
Due to the location of the pipeline, there are significant traffic impacts once the works are carried out. This work is critical to prevent the pipeline from failing which could lead to untreated wastewater being discharged into the environment and multiple lane closures for replacement works.
Construction work is expected during the Easter school holiday from 12 – 26 April 2025. All works are weather dependent. Crews will be onsite 24/7 for approximately two weeks. Speed limits will be in place and one northbound lane is anticipated to be closed.
Frequently Asked Questions
What’s the scope for this project?
At this stage, the scope of this project is for the urgent renewal of a 590m wastewater pipeline which is jointly owned by Hutt City Council and Upper Hutt City Council that is in poor condition.
This is the main pipeline serving approximately 50,000 people including Western Hills in Lower Hutt and Upper Hutt.
- Primary objective: Providing reliable services to customers.
- Secondary goal: Minimising public health risks associated with wastewater and stormwater.
What will the impact be if the pipe critically fails?
There are no indications of imminent failure with the pipe and we’re regularly monitoring its condition.
- In the short term, we have a contingency plan in place to ensure we’re keeping the disruptions to a minimum if a pipe failure occurs prior to the repair.
- And in the longer term, we have a preferred option to rehabilitate the pipeline that will minimise transportation disruption on SH2.
If a pipe failure occurs before the repair, there may be some environmental and transportational impacts depending on the failure and the effectiveness of our operational response.
We’ll be working closely with Hutt City Council, Upper Hutt City Council, Greater Wellington Regional Council and NZTA to determine the best approach. We will communicate with the public to ensure they are aware of the approach, timelines, and any impacts of the work.
What's the timeframe for getting this renewal project completed?
Works will commence on 12 April 2025 with crews operating 24/7 to get this work completed. We expect the works to be completed within two weeks, weather dependent.
What's the traffic impact of this project?
As the wastewater pipeline is underneath State Highway 2 (crossing north of Melling), critical works to line a section of this pipeline will cause significant traffic disruptions, especially during peak times.
To ensure the safety of our workers and road users, traffic management will be in place.
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The works are expected to take place 24/7 for about two weeks from 12 April, depending on weather conditions.
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Traffic management will be between Melling Link and Kennedy Good Bridge.
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One northbound lane will be closed and speed limits will be reduced.
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To balance the traffic impacts on all lanes and local roads, one southbound lane will be converted into a northbound lane - there will be two northbound lanes towards Lower Hutt/Upper Hutt and one southbound towards Wellington City.
Please be patient with us and plan ahead during this time.
Why will there only be one southbound lane during the project?
This traffic management plan best balances the impacts on southbound and northbound traffic, as well as local roads in the area.
The decision to convert one of the two southbound lanes into a northbound lane is based on the following factors:
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The morning peak traffic is more spread out whereas northbound traffic in the evening is more concentrated, creating a much narrower peak.
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There are more easily accessible alternative routes for the southbound travelling public, including Eastern Hutt Road, SH58 via Haywards and local Hutt roads, which alleviates the pressure on southbound lanes.
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The layout and spacing of the intersections mean it’s more challenging managing northbound traffic queues, which is why an additional lane is needed.
Why is the traffic layout not switched in the morning and evening?
This is an option we’ve looked into. However, due to significant health and safety risks with switching the layout twice a day for two weeks for workers, traffic controllers, and the travelling public, we decided to keep the traffic management layout consistent over the duration of the project
Even at times in the day when traffic volumes are lower, switching between traffic layouts would be disruptive as this could take between an hour to an hour and a half. There’s also a significant cost to switching the traffic layout over the duration of the works.
We opted for a layout to have two northbound lanes towards Lower Hutt/Upper Hutt and one southbound lane towards Wellington City open because this best balances the impacts on both lanes as well as local roads in the area. Southbound traffic is more spread out in the morning and easier to manage. There are also more easily accessible alternative routes for the southbound travelling public which will alleviate the pressure on southbound lanes.
Does this point to a bigger problem with the wastewater network?
This finding further highlights the ageing infrastructure in the Wellington region and the importance of our existing programme of work for condition assessment our council owners fund us to do which support the prioritisation of pipe repairs and renewals throughout the region.
In this case, the condition assessment has identified that the pipe is in worse condition than anticipated, so has enabled repairs to be developed prior to the assets failing.
All Updates
One manhole reinstatement to go, partial removal of traffic management will start on Saturday night.
Complete reinstatement of road surface planned for Sunday followed by the removal of the remaining traffic management by Sunday evening.
Reinstatement is well underway with three manholes set yesterday and the road around them resurfaced. Two more manholes will be set.
The bypass and the hoses are to be removed today.
Works remain on track for the traffic management to be packed up on Sunday.
The fourth and final liner was pulled into place yesterday and will be cured today.
The works are all on track to have traffic management all packed up and removed by Sunday evening.
Traffic flow have been lower than expected this morning.
The third liner was successfully installed yesterday and cured overnight. Work on the fourth and final liner is underway and is expected to be completed tomorrow with early reinstatement work beginning tonight.
Traffic impacts continue to be as expected.
We'll provide further update tomorrow.
The second and final week of the lining works on SH2 Melling is now underway!
The second liner was successfully installed and cured yesterday. Works on the third liner are taking place today. After the lining, the liner will be cured overnight.
Risk mitigations are in place for rain that will come through tomorrow morning to manage the increased flow.
Traffic impacts continue to be as expected. We'll provide further update tomorrow.
The team is back onsite today to carry out work on the next liner.
Cleaning of the second section of the pipeline is now underway, with CCTV and the lining to follow. Curing of this liner will take place through the night shift.
There was more rainfall than anticipated yesterday but flows remained steady and there were no issues with the pumps.
There are no expected issues with weather over the next two days. Traffic impacts remain minimal over the long Easter weekend.
We'll provide further updates tomorrow.
Great news - the first liner, which is the heaviest and most complicated one has now been successfully pulled and cured!
Due to predicted rain today, onsite work will take a short pause. This will give the team a well-earned break before returning to pull and cure the remaining three liners over the next few days! The team has been working hard since last Saturday to move the project forward, despite some initial challenges with site set-up and lining equipment.
We’re predicting minimal impacts from the upcoming weather, and crews will be taking full advantage of this to keep the momentum going.
We’ve been making every effort to minimise disruptions as much as possible, but we know that disruptions are inevitable with this work being on SH2. A huge thank you to impacted Western Hills residents and road users for your patience and understanding!
Please be patient and use alternative routes where possible. Fortunately, we’ve seen an improvement in traffic delays over normal and minimal impacts or evening peaks.
We're currently behind schedule due to equipment issues. This means the liner was not cured last night as planned. The team is working to address these and cure the liner this afternoon.
Heavy rain forecasted for tomorrow and may mean works will be put on hold. The bypass hoses will be removed if a wet weather contingency is required.
We're working hard to get back on track with the programme.
Impacts on traffic remain to be within the expected range with average delays of 10 minutes above normal for morning peaks and minimal impacts on afternoon peaks.
We're continuing to review our daily progress and will be providing daily updates as works progress.
10 am update: They expect to complete this by midday and cure the pipe this afternoon with the aim to have this completed tonight.
The second liner will be pulled and cured tomorrow following cleaning and flushing of the line.
The order of the works have been reprogrammed to prioritise liner installation this week and reinstatement works to be carried out next week. This will ensure critical works are completed while weather conditions are favourable.
Traffic delays are improving significantly, with this morning's delay being only about 12 minutes above normal. The delays for evening peaks continue to be minimal.
Weather is looking good, our model shows a green light for the next two days. There are conflicting forecasts for Friday, we will continue to monitor this. A further update will be provided this evening to confirm the status of the current liner.
7 pm update: The UV tray is currently in the line and curing is underway. Shots 2 and 3 are to be flushed and cleaned tonight, and the intention is to start pulling the second liner in the morning.
10 am update: There's been some slight delay with setting up the bypass for the over-pumping system which will keep the wastewater network flowing while this section of the pipeline is isolated for the lining works.
The team is expecting to complete the installation of the bypass and get it up and running by midday. Once this is completed, the flushing and CCTV of the line for the first liner will take place this afternoon.
Lining specialists are onsite to pull and start curing the first liner tonight.
Traffic delays have improved compared to yesterday. Morning delays are more significant than in the evening. Please continue to plan ahead and use alternative routes where possible. Weather conditions are favourable over the next couple of days. We'll continue to assess this./
A further update will be provided this afternoon.
4.40 pm update:
Works for the day are progressing well, the bypass arrangement is now operational. The line is currently being flushed with CCTV inspections to follow. We aim to pull and cure the first liner in the night shift tonight. The team is tracking well to get back on schedule.
There were significant traffic delays this morning. Please plan ahead and expect significant delays, especially during peak times. Use alternative routes where possible.
Works are underway to prepare for the lining works tomorrow. Pressure testing for the over-pumping system will be carried out this morning. The bypass for the over-pumping is expected to be running by midday.
Flushing and cleaning of the first of the four lining shot will be done this evening. The first liner will be pulled tomorrow morning.
Weather is looking good for the next couple of days. Forecast rain towards the end of the week is within pump capacity. We'll continue to monitor this.
Works are progressing well on-site with the hose being laid out to establish the by-pass for the over-pumping system. This will keep the wastewater network flying while the lining works are carried out.
The team is on track to start the lining works tomorrow as scheduled.
Weather conditions remain favourable over the next few days. There's some rain expected this Thursday and we'll continue to monitor this.
One of the two southbound lanes towards Wellington City has been converted to a northbound lane towards Lower/Upper Hutt to manage traffic impacts. Please follow signage and traffic controllers in place.
There's been a slight delay for road users along this stretch of SH2 yesterday. Plan ahead and expect delays, especially during peak times.
Thank you for your patience and understanding as we carry out this work!
Favourable weather conditions are expected over the next couple of days with a low risk to the project and site arrangements in place.
Final traffic management set-up and installation of the bypass and hose for the over-pumping is now underway. This over-pumping system will keep the wastewater network flowing while the lining works are carried out in this section.
The team is working hard to progress work as scheduled and expect to be fully on track by tomorrow morning.
Updates will be provided everyday for the next two weeks until works are completed.
Critical works on a wastewater pipe underneath State Highway 2 (SH2) is starting from tonight, Thursday 10 April and will take approximately two weeks to complete.
As these works are to insert a liner into the wastewater pipeline underground, the project is weather dependent and certain activities cannot be carried out in heavy rain.
The recent weather forecast predicts minimal rain during the first week of the project which will not impact the works. We will continue to monitor weather conditions and provide updates if weather impacts occur.
Traffic management set-up will start tonight, Thursday 10 April. The lining works are expected to take place 24/7 for two weeks from this Saturday 12 April 2025.
· Traffic management will be in place between Melling Link and Kennedy Good Bridge. Speed limits will be reduced from Friday 11 April onwards.
· Other traffic management measures including a northbound lane closure and no exit from Tirohanga Road and Block Road onto SH2 will be in place from 12 April.
· During the works, there will be two open northbound lanes towards Lower Hutt and Upper Hutt and one southbound lane towards Wellington City.
We’ll provide further updates on the project as these works progress. You can also get the latest information on our Facebook and this project page.
Heads up - Critical lining works on a wastewater pipe underneath SH2 will take place 24/7 for two weeks, from Saturday 12 April.
To ensure the safety of the workers and road users, traffic management will be in place from Melling Link and Kennedy Good Bridge. One northbound lane will be closed and speed limits will be reduced.
Below are the key things to note:
• One of two southbound lanes will be converted into a northbound lane.
• There's no turn out of Tirohanga Road onto SH2 - please use Harbour View Road instead.
• Block Road exit onto SH2 will be closed to all traffic except emergency services and buses replacing trains.
• To stay on SH2 South when heading towards Wellington City, stay on the left lane.
If you need to access the Melling Station on foot, use the crossing at Harbour View Road as the crossing from Tirohanga Road to Block Road will be closed.
During this time, 145 and 149 bus services will not stop at Melling Station, and instead continue to Waterloo Station. From 22 to 24 April, Melling Line trains will run on alternative timetables. For more info, visit the Metlink website: www.metlink.org.nz
This work is weather dependent, and regular updates will be provided on our social media channel and project page leading up to and throughout the project.
Please be patient with us and plan ahead to allow for extra travelling time over this period.
Traffic delays expected as critical works to line a section of a wastewater pipeline underneath SH2 starts soon.
Work is expected to take place 24/7 for two weeks from 12 April 2025, aligning with the Easter school holidays, when traffic volumes are generally lower, to minimise impacts on road users. During this time, daily updates will be provided on Wellington Water’s website and social media platforms.
To ensure the safety of the workers and road users, traffic management will be in place from Melling Link and Kennedy Good Bridge. One northbound lane will be closed and speed limits will be reduced.
When heading north towards Lower Hutt and Upper Hutt:
-
To balance the impacts on both lanes and surrounding local roads, one of two southbound lanes will be converted into a northbound lane within the work zone during this time.
-
To access Western Hills, use the left lane onto Harbour View Road and Tirohanga Road as usual. However, you can only exit using Harbour View Road.
-
If heading to Hutt Central, use Melling Link instead of Block Road to turn right. Block Road will be closed to all traffic except buses and emergency services.
When heading south towards Wellington City:
-
Use the left lane to stay on SH2 South.
-
To access Western Hills, use Harbour View Road instead of Tirohanga Road, as there is no right turn at the Tirohanga / Block Road intersection.
This traffic layout has been chosen because the morning peak traffic is more spread out and there are more easily accessible alternative routes for the southbound travelling public. The layout and spacing of the intersections also make managing southbound traffic queues easier.
This work is weather dependent, and regular updates will be provided.
These works are crucial to prevent the pipe from failing, which would cause untreated wastewater to discharge into the Hutt River. This would pose significant risks to both public health and the environment and cause and significant road closures.
To ensure the safety of our workers and road users, traffic management will be in place. Here are some key info:
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The works are expected to take place 24/7 for about two weeks from 12 April, depending on weather conditions.
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Traffic management will be between Melling Link and Kennedy Good Bridge.
-
One northbound lane will be closed and speed limits will be reduced.
-
To balance the traffic impacts on all lanes and local roads, one southbound lane will be converted into a northbound lane - there will be two northbound lanes towards Lower Hutt/Upper Hutt and one southbound towards Wellington City.
More details on the traffic management will be available soon.
We understand that traffic disruptions caused by this, especially during peak hours, can be frustrating. Please be patient with us and plan ahead during this time as we carry out these critical works.
Critical rehabilitation work will soon begin on the Western Hills Sewer Main - a key wastewater pipeline running beneath State Highway 2 (SH2) in Lower Hutt.
Work is expected to start on the 12 April 2025, aligning with the Easter school holidays, when traffic volumes are generally lower, to minimise impacts on road users. The works will be carried out 24/7 and are anticipated to take two weeks. During this time, daily updates will be provided on Wellington Water’s website and social media platforms.
At this stage, it is likely that one lane will be closed and speed limits will be reduced for the safety of both motorists and contractors. While efforts have been made to minimise disruptions, significant delays are anticipated at peak times. Alternative routes will be advised where possible.
We appreciate that roadworks can be frustrating and disruptive. We ask the public to please be patient with us while we complete this crucial work and to plan ahead and allow extra time for travel during this time. Once the traffic management plan has been finalised, we'll provide details on the impact and the areas most impacts on SH2.
Planning is underway to prepare for the works to commence in the second quarter of 2025. We're also working hard to ensure the potential impacts on SH2 are minimal.
The condition of the two upstream lengths of pipe has been confirmed as poor (condition grade 4). Corrosion is significant so they will be included in the works. The completed options report has confirmed CIPP as the option. Tenders were issued for the works last week and closed on 8 November.
The project team are making great progress with the design phase.
We’ve identified CIPP (Cast-in-place pipe) pipelining to be the most viable option to remediate the wastewater pipeline. Our contractors are now working through finalising the concept design and developing a budget estimate. We have a live operational contingency plan in place
We’ll keep you updated as this work progresses.