Wastewater Treatment Plant Wetlands

The Manawatū Wastewater Treatment Plant Wetlands is a project designed to improve environmental outcomes for the Ōruoa River by discharging treated wastewater to the wetlands before it is released into the river. This will add an extra filtration process that will help to break down any remaining contaminants in the water.

Council has partnered with Ngāti Kauwhata on this project, as the river holds special significance to them and their Job for Nature team have been heavily involved in the construction. Earthworks on the wetlands began back in August which involved moving approximately 30,000 cubic metres of soil and is almost complete. Next up we’ll be building the inlet and outlet structures over summer followed by planting due to start around May.

The wetland will be planted with over 80,000 native plants specifically selected for their treatment properties. All of the plants have been sourced and grown by our own Kawakawa Nursery and the Jobs for Nature team with a huge amount of time and effort put in.

The wetland has been designed to treat over 6 million litres (6000 m3) of wastewater per day and will take 3 days for the water to travel it’s length. It is hoped that the wetland will create a diverse ecology mimicking naturally occurring wetlands as much as possible.

The access road in the middle of the wetland has been constructed using recycled material from Central Demolition’s concrete crushing operation which is nearby. It’s another great example of how that partnership between Council and Central Demolition has been beneficial for both parties, and the wider community.