Paremata Station Road pump station alterations

Work to undertake alterations to the current wastewater overflow system at the pump station on Station Road, Paremata was completed in June 2024.

The overflow pipe size will be increased to help handle larger wastewater flows during high-intensity rainfall events. This will reduce the impact of uncontrolled wastewater from severe weather events being released at the pump station and manholes within Paremata School.

Road closure

To carry out the work safely, traffic management will be in place on Station Road and Paremata Crescent so contractors can access the pump station. One lane will be always open, but delays can be expected during work hours. Please use SH59 as an alternative route where possible.

Work areas will be fenced off. Pedestrian diversions will be place around the worksite and there will still be vehicle and pedestrian access to the Paremata Park and Ride car park, and businesses on Station and Paremata Road.

The local wastewater network is known to have high levels of inflow and infiltration that result in wastewater flows exceeding the capacity of the Station Road pump station to keep up during heavy rainfall. Once the pump station reaches its capacity, the wastewater flows back up and finds its way through a pipe that runs directly through Paremata School.

Several previous overflow events resulting in wastewater discharge from the Station Road pump station have posed a public health hazard to Paremata School, public transport users and local businesses. This work is vital to ensure the safety and well-being of our communities by minimising public health risk.

Why are we doing this?

Once completed, the frequency of uncontrolled wet weather bypass discharges will be reduced to help with ensuring wastewater remains within the network during severe weather events. This will help to mitigate a significant public health hazard, especially for Paremata School, which has been impacted by closures for intensive cleaning following severe weather events in recent years.

The proposed works will increase the capacity of the pump station overflow and reduce the risk of wastewater overflowing to land.

Longer-term, the Paremata Wastewater Trunk Upgrade project will further reduce public health and  environment risk reducing the flow of water to the pump station during times of heavy rain.

Wellington Water requested funding for the Paremata Wastewater Trunk Upgrade Stage 2 through Porirua City Council’s LTP (Long Term Plan) process, and the council has consulted with its community on deferring the project. The council will be confirming its funding decisions in the next few weeks. Until this project is funded, and subsequently delivered, increasing the capacity of the overflow at the Station Road pump station is necessary to mitigate the current public health risk.