Construction of a building for receiving organic waste at Green Island will be completed by then, but the Dunedin City Council does not yet have permission to create a composting operation at the site.
From July, households in urban areas will be asked to use a separate bin for food scraps, or a bin for food and garden waste, and put it out on the kerb for collection.
Removal of most organic waste from the general waste stream is expected to make a significant dent in landfill tonnage and reduce carbon emissions.
However, the food and garden waste in the kerbside collection will initially be among material taken to Enviro NZ’s composting plant in Timaru.
It will be combined with any green waste dropped off by the public at Green Island, shredded within the enclosed organics building and then loaded on to trucks for composting outside of Dunedin.
An update about various waste projects was included in the agenda for the city council’s infrastructure services committee meeting next week.
It is intended a composting operation at Green Island will be part of a broader resource recovery park to be developed in the 2024-25 financial year.
The council is due to apply for resource consents for the park this month.
A report to the committee said council staff were working through the concept, detailed design, consenting and procurement required for the resource recovery park.
Transporting material to Timaru would stop once the park was operational, and both organic waste and mixed recycling would be processed at the Green Island facilities.
Removal of most organic waste from the general waste stream, combined with new waste diversion facilities, could achieve a reduction of 10,000-14,000 tonnes of waste to landfill a year, the council said.
This would result in a 24% reduction in associated carbon emissions.
The report included updates about preparing to close the Green Island landfill and build a new landfill at Smooth Hill, near Brighton.
Construction of the new landfill is expected to start in 2026-27 and it could open in 2029.
At least three years of baseline environmental monitoring is required before construction can start.
The monitoring was under way, the report said.
In the meantime, the council has applied for an extension to consents for running the Green Island landfill.
They were set to expire in October, but the Otago Regional Council confirmed the city council had the right to continue the Green Island operation until replacement consents had been decided upon and any appeals resolved.
If the extension is granted, the landfill might operate until 2031, it has been signalled.
The southwestern area of the Green Island landfill is considered by the city council to have room for more waste.
The council said it was "actively committed" to achieving waste reduction and diversion targets, but another class 1 landfill was needed once Green Island reached capacity.
"Council is therefore progressing the establishment of a modern landfill facility at Smooth Hill to meet future demand," the report said.
"The Green Island landfill capacity provides flexibility for fluctuating waste demands and ensures there is a viable option available for the continued disposal of waste until such time as the resource recovery facilities are fully operational and waste disposal at Smooth Hill can commence.
"This includes accommodating the potential for construction delays to the Smooth Hill development and allows for a period of transition in operations between the two landfills."
Exporting waste to a neighbouring district could be an alternative to building the Smooth Hill landfill, but at least two city councillors have dismissed the idea as irresponsible.
It might also be a back-up option if the application for consent extension at Green Island fails.