Your Wastewater System

The Porirua wastewater system is made up of a large network of pipes and pumping stations that feed into the treatment plant at Rukutane Point.The system serves Porirua and Northern Wellington suburbs.

The network

The network starts at your home with your household plumbing, a gully trap and lateral pipes that carry your wastewater into the public wastewater network, which consists of:

  • 180 square kilometres of catchment across Porirua city and north Wellington suburbs Newlands, Johnsonville and Tawa
  • 573 kilometres of pipes and 54 pumping stations
  • Feeds into the wastewater treatment plant at Rukutane Point 

The treatment plant

  • Capacity to treat 1000 litres of wastewater per second - to be upgraded to 1,500 litres per second by late 2020
  • Treated effluent is discharged out to sea via an outfall off Rukutane Point
  • Improved quality of discharge is keeping the coastal shores cleaner and safer.

Issues with the wastewater system

  • Wet weather and dry weather overflows and leaks from the network are discharges from the network that flow into our streams and the harbour. Dry weather overflows can occur when there is a blockage in the network. Leaks are from a hole or breakage in the pipe.
  • Stormwater inflow and groundwater infiltration are where water gets into the network pipes and contribute to overflows
  • Overflows at the plant happen when wastewater inflow exceeds the plant’s capacity to fully treat it. This partially treated wastewater is combined with fully treated wastewater and discharged out the Rukutane Point outfall. Heavy rainfall can cause these overflows.