Watercare’s three-stage plan to replace the flood-damaged wastewater main beneath the Parnell Rose Garden is underway at the intersection of Judges Bay and Bridgewater roads.

Instead of doing a like-for-like repair that would see a wastewater pipeline installed through the Parnell Rose Garden, Watercare is building around it.

The $13.2 million permanent three stage solution consists of a small prepackaged submersible wastewater pump station, rising main and gravity sewer.

This permanent solution will replace the temporary robust repair that has been in place since last March when a broken wastewater pipeline, located approximately 25 metres beneath the Parnell Rose Gardens, was discovered during a CCTV inspection.

The break in the pipeline was caused by extreme flooding during last year’s summer storms.

Watercare head of wastewater planning Andrew Deutschle says the permanent solution will reduce maintenance difficulties and increase the resilience of the local wastewater network.

“We did consider the possibility of installing a gravity sewer main beneath the rose garden, however, it was not feasible as our crews would have needed to install the pipeline down to 28 metres underground and we would have lacked flexibility for future infrastructure upgrades.”

Deutschle says by installing both pipelines around the park, it will enable our crew to use Horizontal Directional Drilling (HDD).

“Using this drilling technique will enable us to install both pipelines at shallow depths underneath the road without having to excavate the surface, reducing cost and disruptions.

“Plus using horizontal directional drilling will enable us to get the job done faster and reduce carbon emissions by an estimated 18.7 per cent.”

Watercare project manager Frank Lin says Watercare and construction partner Pipeline & Civil are working at pace to have the permanent works completed by July next year.

“Our crews are carrying out excavation works for Stage one, the installation of a small prepackaged submersible wastewater pump station near Judges Bay and Bridgewater roads intersection.

“The circular wastewater pump station is 3.5 metres in diameter and is prepackaged with two pumps, operational and electrical equipment already installed.

“The pump station will be buried underground and can pump up to 30 litres of wastewater per second, enabling more capacity in the network to service the current and future population growth.

Lin says Stage 2 of the works, the installation of the rising main along Judges Bay Rd, will start in early December, with Stage 3 of the works – the Cleveland Rd Gravity Sewer main works – beginning in January next year.

“The rising main will connect in at the pump station and make its way up Judges Bay Rd to connect in with the gravity sewer main from the corner of Cleveland and Gladstone Rd.

“From there, the gravity sewer main will run all the way down Cleveland Rd to connect in with the existing network underneath St Georges Bay Rd.”

Lin says residents and motorists can expect traffic disruptions.

“Residents will be notified in advance and traffic management plans will be implemented to minimise the interruptions.

“Working hours will be 7am to 6pm, Monday to Friday, with traffic management in place 24/7 for safety.

“On-street parking will be limited. Pedestrian access will be maintained. Noise and vibration may occur, but monitoring and management measures are in place to ensure the impacts are within the permitted levels.”

Waitematā Local Board chairperson Genevieve Sage is impressed with Watercare's permanent solution for Judges Bay.

“This permanent solution will help to increase resilience of our wastewater network as well as further protect our local waterways.

“Watercare has created a bespoke solution that caters to the community's current and future needs.

“We thank the community for their patience as Watercare works at pace to get the job done.”

© Scoop Media