Te Kūkūwai o Toa Wetland – the wetland at Elsdon Park – will help reduce flooding and naturally filter stormwater before it runs into Te Awarua-o-Porirua Harbour.
The wetland has been developed in partnership between Wellington Water, Porirua City Council and Ngāti Toa Rangatira (Ngāti Toa), with funding from the Ministry for the Environment Freshwater Improvement Fund.
Wetlands are often described as the kidneys of the planet, because of the way they regulate water flow and filter waste.
The wetland covers one hectare and supports resilient treatment of stormwater runoff from the 40 hectares of commercial and residential areas upstream. There are over 20,000 carefully selected native aquatic plants, covering at least 80% of the wetland surface, to support a vibrant and biodiverse community, and another 15,000 plants around the edge.
Water from the Urukahika Stream (previously in the pipe below Awarua Street) flows into the wetland and spreads across the full area, before gradually flowing out to the harbour. The design avoids areas of stagnant water and will support diverse communities of aquatic insects, birds and fish which feed on biting insects such as mosquitoes. Most of the wetland area will be covered with dense plant cover rather than open ponds.
Naming Te Kūkūwai o Toa Wetland
The name was gifted to the wetland by Ngāti Toa. Ngāti Toa Pou Toa Matarau Naomi Solomon says the opening of the wetland is an important part of the journey to improving the health of Te Awarua-o-Porirua.
“The whenua in which the wetland now sits was a significant site for Ngāti Toa in the past where we gathered kai moana and essential resources for our iwi. Te Kūkūwai o Toa when translated means The Wetlands of Toa in reference to its presence in the heart of Takapūwāhia.”
How the wetland evolved
Te Awarua-o-Porirua was once a thriving tidal estuary and home to marine and migratory fish, shellfish, birds and plants. Land uplift from earthquakes, land reclamation and urban development over the decades resulted in significant changes to the estuary and surrounding wetlands with almost no wetland habitat remaining.
The new constructed wetland system has a dedicated flood retention area and the new realigned stormwater pipeline has been designed as a cost-effective bypass to protect the wetland in high flows.
The wetland was constructed in the first half of 2022 and officially blessed and named Te Kūkūwai o Toa by Ngāti Toa in June 2022. It is the final stage of a major, $14.5 million project to upgrade the stormwater network in Porirua to alleviate flooding at Porirua school and in the Porirua CBD area, reduce contaminants and sediment and improve the health of the harbour.
