Kia ora from the Lyttelton Harbour Wastewater Project team.

Work is steadily progressing on the Heathcote Valley pipeline and upgrade and build of four pump stations around Lyttelton Harbour. We completed trenching across Ferry Road during the school holidays, one important step closer to connecting to our target, Pump Station 15 in Alport Place. Our project team are holding information sessions in Governors Bay next week and would love to see you there.

Thank you all for your patience as we work towards ending the routine discharge of treated wastewater into Lyttelton Harbour.

Did you know the Alport Place pump station, known as Pump Station 15, manages over 30 per cent of Christchurch's wastewater? It's also the terminal point of the Heathcote Valley pipeline and will soon receive all of Lyttelton Harbour's wastewater, before pumping it on the main treatment plant in Bromley.

Four metres deep and 40 metres long - here's a peek of the trench we dug across Ferry Road from the corner of Gould Crescent and into Alport Place to lay a section of the wastewater pipeline.

This installation was done as half of the trench at a time to ensure we could maintain traffic flows with minimal diversions in place.

We are digging below the water table and will need to dewater the trench while works are underway. Our contractors worked through the night to open up the road and then seal it up again. These are some of the measures we take to ensure that we minimise disruption to the people of Christchurch when installing pipes under one of Christchurch's busiest arterial roads!

You might have received a works notices saying we're potholing for services, or spotted us on the job digging up sections of the road with high pressured water. Hydro-excavation is the science of digging with water to locate existing pipes and cables. This photo is a section of footpath and road that's been freshly potholed. This is a good example as to why we need to physically locate these services before we starting digging to install infrastructure.

From left to right, the purple pipeline is fibre optic cable, the grey is telecommunications and the orange is power. To lay our wastewater pipeline, we need to plot a course around these essential services or shift them. That's why it's so important to locate these services before we start to dig our trenches for the wastewater pipeline.

We've laid over 400 metres of pipeline along Mauger Drive and are opening up the road in 200 metre sections, laying the pipeline, then closing the road up behind us.

Right now we're digging the deepest section of Mauger Drive, on the intersection with Warner Place. The trench is 4.5 metres at its deepest point and we're moving forwards at around 15 metres per day. Once we get under the large stormwater pipe, we can raise the trench depth and be able move forwards faster and return your road to normal.

Our subcontractors are working hard to minimise any disruption this work is causing you, so if you have any concerns please come and have a chat. You can ring our subcontractor on (insert number here) or call Christchurch City Council on 03 941 8999 or send us an email here.

Access to the local shops will remain open at all times while we lay the pipeline along Port Hills Road. You won't be able to park on the road, but there's parking available onsite at the Maltworks shopping complex. Thanks for your patience as we complete the Heathcote Valley Pipeline.

Want to know more about the Lyttelton Harbour Wastewater Project? We are holding information sessions at the Allendale Hall, 154 Governors Bay-Teddington Road and would love to see you there.

Session 1: Wednesday 31 July from 12-2pm

Session 2: Thursday 1 August from 4-6pm

RSVP to infrastructurenews@ccc.govt.nz or come along on the day. The project team looks forward to answering any questions you may have.

We recently used a 100 tonne mobile crane to lift a 17 tonne, 600,000 litre stainless steel buffer tank into position on our site at Cashin Quay. We have finished welding the tank, which will then be cast into the concrete foundation below. We then fill the tank up with water and conduct a leak test. This buffer tank installation is part of the measures we take to ensure that we can control overflows during high rainfall events.

We have been making good progress with the pump station. The wet well and pump foundation slabs have been poured and retaining walls are now complete. In the coming weeks, we will install a new stainless steel wet well tank and start with the installation of the new pumps, an electrical room and cables.

Excavation for the wet well at Simeon Quay is complete and we have made the area safe for workers using shotcrete and mesh. Over the next few weeks, we will continue to construct the wet well by installing reinforced pre-cast concrete risers onto the foundation at the base of the excavation. Wet well construction will take a couple of months and once its complete, we will start installing sewer pipes, which will connect the Simeon Quay pump station to the other project stages, as well as water and stormwater pipes.

We need to close the Governors Bay foreshore track from Monday - Friday for two months while we install a new electrical cable and pipeline between the Jetty Rd pump station and the new Governors Bay pump station. 

The track will re-open on weekends.

The pipeline will replace the existing pressure pipe between the Jetty Rd pump station and the new Governors Bay pump station. The new power supply cable will connect the soon to be installed generator at Governors Bay pump station to the existing Jetty Rd pump station. This will increase resilience in the case of a power failure and mitigate overflows of untreated wastewater into the harbour.

There will be trucks, rock breaking equipment and heavy machinery, including an excavator that will block the full width of the access track and will need to swing 180 degrees to install and backfill the pipeline. Truck access to the excavation will be from trucks reversing down the track from the Jetty Rd pump station towards the Governors Bay pump station.

In the interest of public safety, we feel the safest and most efficient way to complete this essential work is to have the foreshore track closed off while works take place.

We understand this is a popular walking track for residents and that's why we're making sure the track will be open on weekends. We'll be working as quickly as possible to return the foreshore track to normal.

The track will be closed Monday - Friday in August and is planned to reopen at the end of September.

Once complete, all of Lyttelton’s Harbour’s wastewater will be redirected to the main Christchurch wastewater treatment plant in Bromley. This will help improve the health of our harbour for current and future generations to enjoy. You can find more information about the Lyttelton Harbour Wastewater Project on Council website.

If you know of anyone who would like to receive this e-newsletter please ask them to email their name and residential address or organisation to infrastructurenews@ccc.govt.nz and ask to be added to the Lyttelton Harbour Wastewater project e-newsletter distribution list.

If you have any questions, or would like further information on the project, please call us on 03 941 8999 or visit www.ccc.govt.nz