Kaitoke pipe bridge replacement

Greater Wellington Regional Council councillors and staff recently joined the team at Wellington Water on a site visit to Kaitoke where they got a first-hand look at all the impressive work done.

The old concrete flume bridge has been removed and the pedestrian link bridge and connection to the new bridge is taking shape.  
 
Our contractor Brian Perry Civil is now focused on the final section of land pipeline from the bridge to the sand filter near the strainer building, which is expected to be completed by August. 

The last piece of work involves crafting a sleek new steel access walkway ramp on the southside and sprucing up the surrounding area with some landscaping.  

Great progress on the Kaitoke pipe bridge project. The old concrete flume bridge has been removed and the team are now working on a new timber pedestrian link bridge and completing the final handrails and steel walkway to the grit trap on the north bank.

We will be placing shotcrete (concrete protection) in limited areas to protect the softer rock and then applying coir matting the rock faces to encourage plant re growth.

The tower crane will be removed early March and the team will focus on the final section of land pipeline from the bridge to the sand filter near the strainer building with aim to complete by end of April. Once complete a new steel access walkway ramp will be built on the south side and the works area landscaped with an expected completion 5 months early.

The Kaitoke pipe bridge project is well on track, with our crews from Brian Perry Civil currently installing the pipe and walkway on bridge.

Each pipe section is put together on a support cradle with access walkway built on top. Engineers from Japan provided extra support to our crews to ensure the pipes are installed correctly.

Our goal is to complete and test the bridge pipework for water diversion by the end of this month. Demolition of the existing flume will kick off in December once the diversion is complete.

A key stage in the Kaitoke Pipe Bridge project has been completed!  

Following a year and half of challengingand complex construction, the 24-tonne, 52-metre-long steel arch bridge has been lifted onto its new home across Te Awa Kairangi/Hutt River.   
 

The bridge will support a 1.5m diameter ductile iron pipe, designed and built in Japan and the largest of its type installed in Aotearoa. It’s been specifically designed to flex in a significant earthquake event and ensure water flow to the downstream water treatment plant at Te Mārua.   
 

This pipe will transport a significant amount of Wellington’s drinking water – up to 140 million litres a day (that's 2 Olympic-size swimming pools every hour!) 
 

The project is on track to be completed in early 2025. Once completed, the public will be able to cross the new bridge as part of the Kaitoke loop path.   

It’s all hands on deck at Kaitoke, Upper Hutt where our crews are busy assembling a brand new pipe bridge that’ll provide a more resilient supply of water to the Wellington region.

It’s pretty staggering the amount of material required and the sheer size of the bridge, here’s some of the highlights:

• A lot of steelwork - 10 arch tube sections, deck stringers, end plates, cross bracings and hangers are now being assembled (we hope to have the bridge assembled by early July)
• The single span arch bridge is 52 metres long, weighing in at 24 tonnes
• The water pipe, sourced from Japan, is made of seismic resilient ductile iron
• Once assembled, a tower crane will move the bridge into position (we plan to do this by around mid-August, weather dependent)

The new pipe bridge replaces the existing one which is ageing and doesn’t meet current seismic loading requirements. Transporting 50% of the Wellington region’s raw water from Te Awakairangi (Hutt River) to the Te Marua Water Treatment Plant & the Stuart Macaskill Storage Lakes, before it begins its journey to taps in our homes and businesses, this is a key regional project.

We plan to carefully demolish the old bridge by mid-2024, once the new pipe bridge is up and running. We expect the project will be complete by early 2025.

We’re making good progress on the project to replace the Kaitoke Pipe Bridge with a new one to help ensure the supply of safe drinking water continues for the Wellington region.

We’ve completed the southern bridge foundation, and we’ll begin piling and construction work on the northern bridge foundation in March 2023.

Our rock anchor stabilisation of the slopes is 60 percent complete, which will mean the rockface remains secure during construction, and into the future.

We’re lpoking forward to the arrival of the steelwork which is currently being fabricated, and due onsite in May 2023.

This month, we assembled a 22 metre crane with a 64.2 metre boom on site at the Kaitoke Pipe Bridge project, north of Wellington.

The crane is an impressive piece of machinery, able to lift 32 tonnes up to 32 metres away, or 11 tonnes up to 62.5 metres away. The crane’s capacity allows us to reach the northern side of the Hutt River, moving loose rock and placing an 8 tonne rig across the river so we can start building the northern foundations of the bridge. 

Assembling the tower crane was no easy feat. A 100 tonne crawler crane was needed because the access road was too narrow for a mobile crane to be brought in to do the job. This is serious heavy lifting!

This month we installed an 18 metre high piling rig as part of our preparation works. Weighing 35 tonnes, this machine drills piles into the ground to support the abutments.

It was no easy feat transporting this big machine! Sitting on a 23 metre long transporter truck, the piling rig took our crews over 3 hours to travel 3km from SH2 to the worksite. The hardest part of the journey was navigating narrow bridges and tight corners.

We are now 3 months into the Kaitoke Pipe Bridge Replacement project and work is progressing well thanks to some favourable autumn weather. 

A lot of preparation is required before we can demolish the old bridge and install a new, more resilient one. We have cleared over 300m3 of rocks and vegetation from the southern slope of the valley to prepare for installation of horizontal rock anchors to the rock face. This challenging work has been done by abseilers supported with a small crawler crane.

We have installed 20 vertical rock anchors to widen the access road for larger machinery to access the site for both constructing the new bridge and demolition of the old bridge.  

Horizontal rock anchoring works will then begin on the southern slope. Over 200+ rock anchors need to be installed, each drilled 6m into the rock face for earthquake stability and resilience.

Temporary rock protection mesh will also be installed above the future northern side of the bridge access. This will protect the crew working on site from any potentially loose rocks while the piling and abutment construction takes place on the northern side of the valley.

Swing bridge loop track closure reminder

Protection of the public and crews is our top priority. In order to carry out this vital piece of work parts of the Swing Bridge loop track continue to be closed to the public. Signs and automatic gates have been installed at Rivendell carpark and around the track to remind people of this closure. Please see the map below for more details.

Kayakers

Kayakers who wish to use the river that flows underneath the bridge during construction hours (Mon – Fri, 7am to 5:30pm) will need to let the contractor know (Brian Perry Civil – 027 345 1993) prior to accessing the river. This is so we can protect kayakers from any overhead hazards that may be present when passing underneath the bridge.

Work has now begun to replace the Kaitoke pipe bridge. The Swing Bridge Loop track is partially closed until December 2024 to allow for this work. We have placed signage on site to clearly show which parts of the track are closed. Please see the map below. For more information about the tracks, visit Greater Wellington's website.

Workers abseiling down the bank to install catch fences and rock anchors.

Today's ground-breaking ceremony marked the start of the Kaitoke Pipe Bridge Replacement Project.

The new Kaitoke Regional Park Arch bridge will replace the current pipe bridge, safeguarding the supply of drinking water for our region. 

The pipe bridge carries water from the Kaitoke intake, located around 1km upstream, where the Hutt River is at a higher elevation.

Greater Wellington councillor Ros Connelly said she was pleased to see work get underway on an important project for the security of the water network.

“This impressive bridge will support a vital pipeline that supplies almost 50 percent of the Wellington region’s raw water,” she said.

“The current pipe bridge is ageing and in need of replacement. I’m delighted the new bridge will not only secure our water supply but be a place where we can come to admire a magnificent landscape.”

Upper Hutt Mayor Wayne Guppy echoed councillor Connelly on the importance of the project to our water supply and the local area. 

“Kaitoke Regional Park is a popular location for tramping and there are lots of beautiful tracks to walk along,” he said. 

“This new pipe bridge will not only be an amazing sight to see but is an important piece of infrastructure that provides raw drinking water to a large portion of Wellington.”  

Wellington Water Group Manager Network Development and Delivery Tonia Haskell says it is great to see all the planning and hard work come together to start constructing the new pipe bridge.

“Construction works begin 7 March and will be completed December 2024.

“To ensure the safety of all park users, there will be no access to parts of the Swing Bridge loop track while construction works are underway.”