Managed airsheds

Following the introduction of the national environmental standard, 71* areas were identified in New Zealand where air quality is likely or known to breach the standards for at least one of the five pollutants – these areas are known as airsheds.
Some airsheds are also identified based on factors such as: the number of people living in the airshed, its unique weather patterns and geography or because local air emissions (eg, local industrial activity) need to be managed separately.
In most cases, airsheds are towns or cities, though in some areas they may include a number of towns – for example, the Otago 1 airshed combines Alexandra, Arrowtown, Clyde and Cromwell.
About two-thirds of New Zealanders live in these airsheds.
As of 2011, 43 of New Zealand’s 71 airsheds are being monitored. Not all airsheds are monitored: if exploratory tests show that air pollutant levels are above the standard or a high number of people are affected, then ongoing monitoring is required.

* Note: 70 of the 71 airsheds are gazetted for PM₁₀ and one is gazetted for sulphur dioxide.

Last updated: 10 December 2012

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