It is hoped the 81,000 aquatic plants will help to filter the water and 48,000 terrestrial plants will provide habitat to native birds and other animals.
The project is being run by the co-governers of Lake Ellesmere which consists of the district council, Environment Canterbury, Te Rūnanga o Ngāi Tahu, Christchurch City Council and Department of Conservation.
Co-chair Steve Lowndes of ECan said the project was a massive undertaking but phenomenal.
“The site looks so different from when we were here in February to bless the project. It fits the ECan ethos of moving from planning to on-the-ground action, he said.
The Ahuriri Lagoon is situated between Tai Tapu and Motukarara and drains into Lake Ellesmere.
The Whakaora Te Ahuriri project started in July last year and is expected to cost $3.5 million.
The plan included the construction of a wetland, plantings and the implementation of a Mātauranga Māori monitoring programme to gauge the changing value of the site for iwi.
Engineering and earthworks were completed last month marking the construction of the wetland and the next stage of planting has begun.
Mr Lowndes said the project will improve water quality, biodiversity and mahinga kai values in the area.
“The wetland is fed by the Halswell River and that will improve water quality by reducing nutrient and sediment passage and creating an open water area designed for mahinga kai.
“It will also provide a pathway to improve the water quality of the associated catchments feeding Lake Ellesmere.”
The wetland is also being set up as a demonstration site to show what can be achieved with constructed wetlands for nutrient stripping.
This will require intensive monitoring and demonstrating results to landowners in the catchment, Mr Lowndes said.
The project is expected to be completed by 2022.