Roading: Pinehaven Culvert Replacement

• Contractor nameDowner
• Completion Date18 March 2022

PROJECT UPDATE - 22 MARCH 2022

With the culverts fully installed and the new roundabout operational, the Pinehaven Culvert Replacement Project is almost complete. There are a few tasks to finish however.

Over the next few weeks the house at 48 Blue Mountains Road that was built over the stream is being demolished and the land will planted and landscaped to be repurposed as a reserve.

There will be a number of native trees and plants put in to replace the vegetation that was removed to allow for the work to be done. The plants have been chosen to most closely resemble the natural bush in the area, including black beech, kowhai and kahikatea. There will be additional planting to replace the removed vegetation downstream of the Pinehaven Road culvert with more low lying species to suit the habitat.

As well as the removal of 48 Blue Mountains Road, the team will also be demolishing 4 Sunbrae Drive.

This property was identified as  flood prone during investigations into flood protection and GWRC acquired it as part of that project. Some of the preparation works for the house demolition are underway with the works expected to take place from April to May 2022.

After the removal of the house the land will be levelled and grassed as a temporary measure before to returning later this year to start stream improvement works through Willow Park. Eventually the 4 Sunbrae Drive lot will become part of the park itself with a new pedestrian bridge to connect Willow Park to Sunbrae Drive.

Final reinstatement in and around 4 Sunbrae Drive, which includes the new bridge, path and planting, will be completed in 2023 as part of the stream improvement works.

With the project all but complete, this will be the last update.

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PROJECT UPDATE - 16 FEBRUARY 2022

This project is all but complete, just some fencing and planting to go. Here's the latest photo of the completed roundabout that was installed after the culverts were replaced.

Thank you to the local community for your cooperation and support while we carried out this work.

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PROJECT UPDATE - 1 FEBRUARY 2022

Happy New Year! We hope you all had a relaxing break over the holiday period. The team is back on site at full capacity now and we wanted to give you an update on what to expect in February.

Pinehaven Road
The roundabout has been built and the road is close to completion, however in the course of the roundabout construction we came across some unexpected ground conditions that required repair.

The repair work for this part of the road has started and we estimate this work will be completed in mid to late February. There will be traffic management in place as required so please take care as you pass through the area.

Sunbrae Drive
The culvert is complete and the road is open for two way traffic. There are a few small activities to be completed such as planting and reinstatement on private property affected by the work so you will still see contractors on site until this is all done.

In March, we will be planting on the stream banks around both culverts to replace the vegetation we cleared so we had space to work.

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PROJECT UPDATE - 20 DECEMBER

Unfortunately the weather over the past few weeks meant that we weren't able to get the road temporarily open on 18 December. The Downer team are pulling out all the stops to have it open by 24 December, weather depending of course. To achieve this, they'll be using a temporary surface that will show wear and tear once vehicles are using it. This will be replaced in January.

There will be some work still to do in the New Year, so it will be closed again for a few weeks in January.

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PROJECT UPDATE - 8 DECEMBER 2021

PROJECT UPDATE - 10 NOVEMBER 2021

A lot has happened since our last update in September.

Sunbrae Drive

In September, the excavation was large enough for Downer to pour the concrete foundations and install the large precast units that make up the culvert. The redi-rock walls have been installed, and towards the end of October, the team began backfilling and compacting the road over the culvert.

The new footpaths have now been poured and we're on the home straight with the surfacing. The great news is that we will be ready for opening the week commencing 15 November.

There will still be a small amount of work to finish around Sunbrae Drive, including a small extension to the downstream walls, new fencing and the planting. The stream banks will be covered to wait for the planting to be done in the autumn.

Pinehaven Road

Over the last few weeks the team has installed the remaining culvert units and redi-rock walls. They have also installed the gravel and rocks within the culvert to recreate a natural streambed effect. Large rocks called riprap have been used to break up the flow of water.

If an artificial water course is too straight and smooth, the water flows too fast for fish to make their habitat or be able to swim upstream, nor can the aquatic plants get a foothold. By breaking up the flow and creating an environment that provides the pools of slower water around the rocks, a natural ecosystem of the stream is enabled to re-establish once the work is finished.

In March next year, Downer will begin to replant the area with natives that will further enhance the natural look. Autumn is the ideal time for planting, until then the stream banks will be stabilised with grass to make sure there is no sediment run off over the summer.

Next steps

While the new culvert is close to completion, Pinehaven Road will remain closed until early 2022 so the contractors can use this time to build a new roundabout at the Pinehaven Road/Blue Mountains Road intersection. Having the contractors already on site was a good opportunity to carry out this important safety improvement for the area. We'll provide more information about the new roundabout over the next few weeks.

 

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PROJECT UPDATE - 10 SEPTEMBER 2021

As soon as we moved to AL3, the Downer team were back at work again and some great progress is being made.

Despite a flash flood event on Tuesday night, the team were still able to install the new sections of culvert on Wednesday and Thursday. Residents and passersby will have noticed the large precast concrete sections of culvert coming in and the crane lifting the sections into place.

 There is heavy rain forecast again overnight tonight and the team is busy protecting the site on Sunbrae Drive from more flooding as we have a concrete pour booked in for Monday.

Nearby locals will notice a lot of activity tonight and tomorrow. There will be extra pumps working to keep the site as dry as possible which might be a bit noisier and the team apologises in advance for any disturbance.

Weather events such as the one on Tuesday night and forecast tonight only help to demonstrate how important the new culverts are to improving the water flows on the Pinehaven Stream. 

 

 

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PROJECT UPDATE - 31 AUGUST 2021

With the change in alert levels at midnight tonight, we are planning to restart work on the Pinehaven Culvert Renewal Project tomorrow. Downer, who is carrying this work out on our behalf, will be working under the Alert Level 3 regulations and their first day back will largely be setting up the site so that they can follow these rules before work resumes.

We want to keep everyone safe so we ask that you try to stay as far away from the team as you can. We know the work we’re doing is interesting for some people, but for the time being please remember to keep those distances.

If you have any questions please feel free to get in touch.

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PROJECT UPDATE - 23 AUGUST 2021

Under Alert Level 4 there is no construction work happening at all. Downer is carrying out daily inspections on the environmental controls and if there’s a big weather event forecast, they’ll do work to protect the site beforehand and clean up afterwards but that's it. This will stay in place for a long as we are at Alert Level 4.

For the moment the stream is not being over pumped, it is being allowed to run through its normal course through the works.

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PROJECT UPDATE - 24 JULY 2021

We're ready to move into the next phase of this work and can confirm that both Pinehaven Road and Sunbrae Drive will be closed to traffic from 2 August 2021 until October 2021.

During this time there will be detours in place for all vehicles. Please see below for the vehicle and pedestrian detour routes.

Detour Route for Pinehaven Road

 

Detour Route for Sunbrae Drive

Pedestrian and cyclist access will still be available. Maps of the pedestrian routes are available on the project website.

There will be alterations to the 115 bus route and temporary bus stops in place.  An overview is below or you can go to metlink.org.nz for more information.

Please contact Belinda Mackenzie-Dodds, Downer Stakeholder Manager by email or by phone on 021826724.

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PROJECT UPDATE - 28 JUNE 2021

Stage 1 – Services Relocation

Since early June, Downer has been working closely with service providers such as Wellington Water, Vodafone and Chorus to relocate the cables and pipes that cross the culverts. These need to be moved out of the way ahead of the planned excavation needed to remove and replace the culverts. This work is progressing well and we are on track for completing this stage in July.

Environmental Management

Minimising our impact on the environment is very important to us.

Prior to excavation, Downer will be placing fish nets up and down stream of the sites and any fish or aquatic invertebrates such as kōura inside these nets will be moved out of that part of the stream. They will have an ecologist to do this.

Once the stream is “defished” they will put dams in at either end of the culverts and the water will be temporarily diverted with pumps and pipes around the sites. They will be constantly checking the weather forecasts and if heavy rain is predicted all excavated areas will be covered by geotextile secured by large staples and sandbags and water will be allowed to overtop the dams and flow through the site if necessary.

Downer will be carefully monitoring the water quality of the stream while they’re working, and working with Greater Wellington Regional Council to ensure any effects are kept to a minimum.

Road closures

Currently we are tracking for the road closures on Sunbrae Drive and Pinehaven Road to be put in place in late-July. We will provide exact dates at least one week prior to the closures starting. 

Downer has been in touch with Metlink, the Emergency Services and with rubbish collection providers to ensure that they are prepared for the closures and can take the detours into account during their operations.

The pedestrian detour for people using Pinehaven Rd will be via the Deller Grove footpath. There will be a temporary footbridge over the stream on Sunbrae Drive so pedestrians can use this to get to Deller Grove or the footpath through Willow Park is an option.

When the closures are in place, we will make sure the route is clearly signposted.

Details of the detour routes and alternative bus stop locations are available below.

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 PROJECT OVERVIEW - 4 JUNE 2021

Work to upgrade two culverts within the Pinehaven Stream that form the road crossings on Sunbrae Drive and Pinehaven Road is scheduled to begin on Tuesday 8 June 2021. Downer is carrying out this work.

The existing culverts are at the end of their design life and are to be replaced with larger culverts and headwalls that meet current seismic and roading standards.

Stage 1 - Single lane only
Start date: 8 June 2021
Duration: Approximately four weeks

The first stage of this work will be to relocate the services such as telecommunications, and water that cross within the area to be excavated. During this time there will be single lane traffic management in place with a stop/go operating.

We estimate that this stage will take approximately four weeks from 8 June. Please be aware that there might be minor delays and factor this into your journey planning. Pedestrian access will still be available.

Letters with information about this work have been delivered to residents in the area, and shared through the channels of Pinehaven School, the Pinehaven Progressive Association, and Silverstream School.

Stage 2 - Road closure
Start date: early July
Duration: Approximately three months

Once the services are safely out of the way, Downer will begin excavation to demolish the current culverts and open up a larger space to install the new culverts that are bigger. These will be lifted into place then the area backfilled and the road reinstated. 

We estimate that this work should begin in early July, with the road closure in place for approximately 15 weeks. This includes the culvert replacement followed by the reinstatement of the roads. Please note, this is weather dependent.

Both Sunbrae Drive and Pinehaven Road will be closed whilst the old culverts are removed and new culverts are installed, Downer will be working on both culverts at the same time. There will be detours for traffic and pedestrians in place and closer to the closure start date we will provide maps and signage.

We appreciate that the road closures will be disruptive. We're working closely with Downer to ensure we do everything we can to minimise the disruption but if you have any feedback we would love to hear from you.

Please contact us by email or by phone on 04 527 2169. Or reach out to Belinda Mackenzie-Dodds, Downer Stakeholder Manager by email or by phone on 021826724.

Changes to the Metlink bus service

Bus 115’s route will be changing slightly to accommodate the closures.

This means from late July to the end of October 2021, bus 115 will not be servicing Sunbrae Drive (between 1A and 5 Sunbrae Drive) and Pinehaven Road (between 1 Pinehaven Road and 34 Pinehaven Road) while the road is closed.

Silverstream Station Access: during the detour and road closures, bus 115 will be stopping at stop 9499 – Silverstream School- Whitemans Road (opposite) (school stop) (outside New World) to allow passengers to access the station.

Due to the necessary changes, bus 115 will be running a modified timetable to make sure bus/train connections can be met and passengers know when to expect the bus at their stop when travelling using the detour route.

Metlink is currently working on the new timetable for bus 115. This will be live on the Detours & Closures page on the Metlink website closer to the road closure dates. 

There will be closed bus stops on the closed roads and in nearby areas where there are restrictions for bus access.

While some of the bus stops are closed, there will be temporary bus stops at key locations for passengers to catch bus 115.

Temporary bus routes detour
July - October 2021

 

 

Contact details

Location

Sunbrae Drive and Pinehaven Road, Pinehaven   View Map