Skip to main content.

Environment New Zealand 2007 questions and answers: Key findings - Freshwater

Environment New Zealand 2007 publications

What are the key findings on freshwater in the report?

In a nutshell

  • By international standards, freshwater in NZ is both clean and plentiful in supply.
  • However, demand for water is increasing, particularly in drier parts of the country, where surface waters such as rivers and lakes already have high levels of water allocated for use. 
  • The majority of our allocated water is for irrigation.
  • Water quality is generally poorest in rivers, streams and lakes in urban areas, followed by farmed areas. 
  • Levels of nutrients (e.g. nitrogen and phosphorus) have increased in our rivers over the past two decades. This reflects the impact of non-point-source pollution (eg urban stormwater, animal effluent, fertiliser run-off). 
  • Other water pollutants (e.g. organic wastes from point sources) have decreased (improved) over the past decade.

Facts and figures

  • New Zealand has more total freshwater per person than more than 90 per cent of almost 200 other countries.
  • Total water use in New Zealand equates to two to three times more water per person than most other OECD countries.
  • The allocation of water in New Zealand increased by 50 per cent between 1999 and 2006. This is mainly a result of an increase in the area of irrigated land; irrigation uses nearly 80 per cent of all allocated water in NZ.
  • In particular, demand for water for irrigation is increasing in the drier, east coast regions of New Zealand, for example, Canterbury accounts for over half of all water allocated in New Zealand).
  • Nutrients (nitrogen and phosphorus - which in excessive amounts reduce water quality) have increased in our rivers over the past two decades.
  • From 1989 to 2003 an annual average increase of 0.5 per cent to 1 per cent occurred for both nitrogen and phosphorus. While this increase may seem small, it signals a long-term trend towards nutrient enriched conditions.
  • Two-thirds of New Zealand’s lakes are in naturally or partially developed catchment and are likely to have good to excellent water quality. 
  • Water quality is generally poorest in rivers, streams and lakes in urban and farmed areas.
  • Sixty-one per cent of the groundwaters that are monitored have normal nitrate levels, the remainder have levels that are higher than natural background levels and five per cent have nitrate levels that make the water unsafe for an infant to drink.
  • Twenty-two per cent of monitored groundwaters have bacteria levels that make the water unsafe to drink (note that it is not known how many of these monitored groundwaters are used to supply human drinking water).
  • Bacteria levels appear to have improved in our recreational waters over the past few years. Over the 2006–2007 summer, 60 per cent of the swimming spots on rivers and lakes that were monitored had low levels of bacteria, indicating that these sites have good water quality and are suitable for swimming.
  • Ten per cent of the monitored swimming spots frequently had levels of high bacteria, indicating that they are generally unsuitable for swimming.
  • Rivers and streams with the highest average levels of bacteria are those in towns and cities.

What is the government doing to improve the quality and allocation of freshwater?

A number of initiatives which are relevant to water quality and water availability are underway and under development. Examples include:

Other questions and answers on key findings

More detailed findings are available for the following sections: