Cambridge wastewater pipe bridge
In December 2018 we completed work to upgrade the Cambridge wastewater pipe and the pipe bridge which crosses the Waikato river. The project is essential to cater for growth and future-proof our infrastructure.
What was involved?
Wastewater from residential properties north of the Waikato River is piped across the river to our treatment plant on the Leamington side of town. The old pipe was running at full capacity and not big enough to cater for present and projected future growth in Cambridge. The pipe bridge, located by the Gaslight Theatre, was also due for replacement.
We replaced the old pipe and increased capacity by 40%. We also replaced the pipe bridge and brought the whole structure up to modern standards, including earthquake resistance.
Project completion - December 2018
Done! We've completed work to upgrade the Cambridge wastewater pipe and the pipe bridge which crosses the Waikato river. Check the video to watch the progress race by thanks to time-lapse photography:
Facts and figures about this project
- The new pipe is 40% bigger
- 17,500 hours of on-site labour
- Two night shifts
- 100% environmental monitoring compliance
- 336 metres of new pipes
- 200 metres of gas main
- Excavated 400m3 of material
- 18 concrete foundations
- 5 cranes needed to launch the new bridge structure
- Size of one crane = 400 tonnes!
Project update - October 2018
Foundations and groundwork for the bridge replacement are now complete. Next, some of New Zealand's biggest cranes will roll into Cambridge to install the new wastewater pipe bridge, and are likely to be on site until late November.
Five cranes, including one massive 400-tonne crane, will be on site to swing the new bridge into place. The new bridge was built off-site in Napier and once it is securely in place, the old bridge and pipe will be removed.
The building site remains off-limits to the public, however those interested will be able to get a good view of the cranes working from the carpark near Resthaven on Vogel St.
Photographs of the bridge installation, 16 October 2018:
Project update - August 2018
We've been on site now for seven months, working to increase Cambridge's wastewater capacity to cater for present and projected future growth.
When we started this project the plan was to upgrade and strengthen the existing bridge. However, we were able to achieve building a completely new bridge for the same price as the upgrade. This is a great outcome but it has meant the project has taken longer than originally planned.
Redesigning the bridge, relocating power and gas and undergoing further geotechnical work has pushed us beyond the original deadline of October. Here' s where we're up to:
- Installation of the new wastewater pipe bridge will be underway in early August.
- A 400 tonne crane will be on site, along with three other cranes that will be used to assemble the new bridge across the Waikato River.
- The bridge, which has been built off-site, will take around ten weeks to put in place.
- Once in place, we will remove the existing bridge and pipe.
The pipe bridge is now expected to be finished by mid-December. Unfortunately, this means the detour of the Te Awa River Ride will be in place until mid-December.
Project update - July 2018
Since January, we have:
- constructed 550m of construction access, crane pads, and creek crossing
- temporarily relocated 200m of gas main
- relocated 70m of underground power cables
- excavated approximately 400m3 of material
- installed approximately 130Lm of new pipes (above and below ground)
- completed 10 concrete foundation structures.
The next stage is to connect the new sewer pipe to the existing sewer network. We'll be doing this work at night because there is less sewage flow. Night work will be underway from 6pm Tuesday 3 July - 7am Wednesday 4 July. To complete the works we will have lighting, mobile cranes, diesel pumps, generators and power tools for cutting, welding and bolting.
We apologise in advance for any disturbance to residents in the area. You will still be able to use your water and wastewater as usual.
Project update - June 2018
We're approximately halfway through construction now and progress is going well. Take a look at the video to see how things are going!
Te Awa River Ride diversion
While work was underway there was a signposted diversion in place for the Te Awa River Ride near the Gaslight Theatre. The red line below shows the part of the River Ride that was closed from 7 February to mid-December 2018. The blue lines show the alternate routes to join the Te Awa River Ride.
Why isn't the sewer pipe used as a bridge for pedestrian/cyclists?
Council did investigate the option of changing the sewer pipe to provide a bridge for pedestrians and cyclists to cross the river. A feasibility report was commissioned in 2014 and estimated the cost at $17.7 million. There was simply no budget available to deliver this - particularly due to the immediate need at the time to enlarge this pipe because of growth in Cambridge. In addition, both banksides are in private ownership and land access negotiations to allow public access would have also required additional time and funding.
The project has a tendered cost of $7.7 million and is being completed by Fulton Hogan.
October 2018 - Cambridge top spot for crane spotting
December 2017 - Work to begin on wastewater upgrade