At the GDC environmental planning and regulations committee meeting last week, councillors were told a concept plan for the wetland and planting had been developed and would be communicated to the community over the next couple of months.
Detailed engineering design of the wetland was under way, with a view to applying for resource consent in autumn.
Construction was planned for summer 2017/2018.
Council acting environmental and regulatory services manager Lois Easton said they would be informing the community about the development and how to care for the stream.
This would involve handing out flyers, education through Enviroschools about stormwater and what people can put down drains, and encouraging the community to be involved in the wetland planting.
The proposed signs would include information about looking after the stream, the biodiversity — such as the abundance of tuna (eels) — and the cultural importance.
The money for the work comes from when the council fined its own engineering and works department $50,000 after human error and system failure led to 450,000 litres of raw sewage pouring into the stream at Heath Johnston Park, which feeds Wainui Stream.
Contractor Fulton Hogan agreed to pay half of the sum.
In addition to stormwater and wastewater, a council investigation last year found long-term water quality issues in the stream. The main culprits were dog faeces and grass clippings rotting in stagnant sections of the stream.
Poor water flow, high water temperature and naturally high sulphate levels were other associated problems.
