The Christchurch City Council introduced the scheme in May last year, in a move to get the country's recycling sold overseas.
Before the plan started, landfills were receiving around 43 percent of the city's recycling bin contents. But now that statistic has been significantly reduced to only 10 percent.
The council's resource recovery manager, Ross Trotter, said there had been noticeable improvements in bottles and containers being rinsed and more lids being removed and disposed of in the red bin.
Measures the council has taken to improve residents' recycling include bin checking, letterbox flyers, gold stars, bin handle tags, chalk markings, and bin removal. Details about what all of these mean can be found here.
Trotter said due to Covid-19, there had been a global increase in demand for New Zealand's paper product because of collection and transportation issues worldwide, which was why clean recycling was so important.
However, the city is still not 100 percent recyclable. Some residents continue to dispose of general rubbish in their yellow bins, causing 10 percent of April's recycling to go to landfill at a cost of $58,000.