More rubbish is being dumped at landfills and less material is being recycled despite the introduction of a fee on household waste, a government report has found.
Introduced in 2009, the levy requires landfill operators to pay $10 per tonne for rubbish dumped on their sites.
However, only 11 percent of New Zealand's more than 400 landfills pay the levy.
The report, released on Monday, says 16.4 percent more rubbish has been sent to tips since the levy was last reviewed in 2014 and 6.3 percent less rubbish has been diverted from landfills for recycling.
It has raised $192 million that has gone into programmes to reduce waste.
Associate Environment Minister Scott Simpson says it remains an important tool to minimise waste but needs improvement.
The report recommends the government consider broadening the levy so it applies to more of the 89 percent of rubbish tips currently exempt.
It also recommends assessing whether different charges should be set depending on what waste is being thrown away, such as setting a higher fee to dispose of more toxic materials.
Mr Scott said levies had been effective in reducing waste in many countries, while New Zealand's levy had already funded many waste-minimisation projects.
This included handing out grants, worth almost $20m, to private businesses this month to help them fund projects aimed at reusing old tyres thrown away in landfills.
NEW ZEALAND'S LANDFILL LEVY
* $10 levy imposed on every tonne of household rubbish dumped at 45 landfills around the country
* 381 landfills are exempt from the levy
* 1.583 million tonnes of waste was thrown into landfills between 2013 and 2016, or 20 per cent more than from 2010 to 2013
* The amount of rubbish diverted for recycling between 2013 and 2016 was 6.3 per cent less than the three years prior
* The levy has raised $192m for the government since 2010 - $46m has gone to councils and $40.9m to 66 projects aimed at reducing waste.
- NZN