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Executive Summary

Drinking-water quality in New Zealand is generally very good. However, disease-causing micro-organisms are present in many of New Zealand’s water sources. These enter our water from a range of sources, including animal and human waste. This places drinking-water supplies at risk.

Effective management of drinking-water requires reducing the risk of contamination at all steps of the process, from source water through to the treatment plant and distribution system. The principle is that if the risk of contamination is minimised at every step, a failure in one step of the process will not lead to catastrophic consequences.

Internationally, lack of recognition of the importance of protecting drinking-water sources has resulted in severe outbreaks of water-borne disease in developed countries, leading to serious illness and deaths. Contamination of water sources is often the cause of these events.

Although New Zealand has been fortunate in avoiding large-scale outbreaks of disease caused by contaminated drinking-water, water-borne disease events have occurred. The largest of these was in Queenstown in 1984, when an estimated 3500 people became ill. Studies by economists indicate that water-borne disease costs New Zealand $25 million per year.

At present there is no explicit legislative requirement for council decision-making processes to consider the effects of activities on sources of human drinking-water. This is a gap that potentially leaves community water sources vulnerable to contamination.

Currently, the degree of protection for drinking-water sources in New Zealand varies greatly across the country. Only three of the country’s 16 regional authorities comprehensively address protection of drinking-water sources in their plans. There is no clear requirement for regional councils to consider effects on drinking-water sources when making decisions on resource consents and regional plans.

The proposed national environmental standard (NES) will require regional councils to ensure that effects on drinking-water sources are considered in decisions on resource consents and regional plans. The exact wording of the standard will be finalised in legal drafting, but councils will be required to:

  • decline discharge or water permits that are likely to result in community drinking-water becoming unsafe for consumption following existing treatment

  • be satisfied that permitted activities in regional plans will not result in community drinking-water supplies being unsafe for consumption following existing treatment

  • place conditions on relevant resource consents requiring notification of drinking-water suppliers if significant unintended events occur that may adversely affect sources of human drinking-water.

Total costs associated with the NES have been estimated at $24.4 million over 20 years, with the majority of costs being borne by consent applicants.

It is difficult to quantify the benefits directly attributable to the NES. However, calculations show that if the NES resulted in a 15 percent improvement in water quality over time, this would result in an estimated health benefit of $27 million over 20 years. In practice, the regulation will deliver much broader benefits, which make the NES highly efficient. These include avoiding the need for future treatment plant upgrades, and maintaining New Zealand’s image as a safe tourist destination and a source of healthy, environmentally sound produce.

It is considered that the proposed NES is the most appropriate, effective and efficient means of achieving the objective of reducing the risk of contaminating drinking-water sources.

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