The proposed NES is a narrative standard that describes how decisions should be made for activities that may affect sources of human drinking-water. It is best viewed as an additional consideration in existing processes for (i) assessing consent applications and (ii) developing regional plans.

There are three components to the proposed standard. These relate to:

  • decisions on resource consents

  • permitted activity rules in plans

  • emergency notification.

It was not practical to set a numerical standard for source water because of the wide variations throughout the country in source water types and quality, and types of treatment plants. For example, some communities obtain their drinking-water from secure aquifers,[In secure aquifers, water has been demonstrated to be greater than one year old and hence unlikely to be contaminated by pathogens (DWSNZ 2005).] and it is so clean that it does not require treatment. Others obtain their water from unprotected surface water (eg, rivers), which can require sophisticated treatment before it is safe to drink. Therefore, it is not practical to specify a single set of water quality criteria that will be suitable for all of these situations. An approach is needed that is flexible enough to be suitable for a wide variety of source waters and treatment plant capabilities, but is sufficiently protective to achieve the objective of reducing the risk of source water contamination.

The original wording of the proposed standard, as notified in the discussion document (Ministry of the Environment, 2005), is provided in each section and also in Appendix 4. Some changes have been made to the original proposal in response to submissions. The reasons for these changes are outlined in this chapter.

4.1 Decisions on resource consents

The first part of the proposed standard affects decisions on resource consents (specifically, discharge permits, or permits to take, use, dam or divert water).

The policy intent for the first part of the standard is:

Consent authorities are required to decline discharge permits, and permits to take, use, dam or divert water, that are likely to result in community drinking-water becoming non-potable or unwholesome following existing treatment.

This part of the standard will only apply to communities of 500 people or more.

Alternative requirement for plants that do not comply with the Drinking-water Standards for New Zealand (DWSNZ 2000):

In situations where existing drinking-water treatment facilities are inadequate (ie, do not currently provide potable or wholesome water), discharge permits, or permits to take, use, dam or divert water, shall not be granted if they will (or are likely to) make the water quality worse at the point where water is taken for a drinking-water supply.

In effect, this adds another consideration to existing consent application processes. When considering an application for a discharge permit, regional councils are already required to assess the effects of the proposed activity on water quality, including effects on aquatic ecosystems. Section 107 of the RMA states that a regional council cannot grant a discharge permit if the contaminant or water discharged is likely to result in freshwater becoming unsuitable for consumption by farm animals, or to have significant adverse effects on aquatic life. Also, permits cannot be granted if they are likely to result in the formation of foams or scums, changes in clarity or emission of objectionable odours.

The proposed NES clarifies that regional councils need to consider the potential effects of activities on the suitability of water for human drinking purposes (after existing treatment), in addition to existing requirements under the RMA. In many situations, existing RMA requirements for aquatic ecosystems and stock drinking are likely to be more stringent than those required for water that will be treated before human consumption, particularly for surface water. The concentrations of many chemical contaminants that aquatic organisms can tolerate are likely to be much lower than those that a drinking-water treatment plant can deal with. Similarly, for microbial pathogens, guideline levels of bacteria for animal consumption are much lower than most treatment plants can deal with.

Likely significant exceptions are pathogens, particularly protozoa, that are not easily removed by existing treatment (eg, protozoa). The other major exception is groundwater, where suitability for drinking may be the major consideration in consent and regional plan decision-making.

Note that the standard will not apply retrospectively (ie, it applies only to new consents. This includes existing consents when they expire and new consents are sought.)

Section 14 activities are included if the take/diversion will increase concentrations of contaminants in source water.

The alternative requirement (see box above) is intended to achieve a balance between preventing ongoing increases in contamination of source waters, while allowing some development in catchments with inadequate drinking-water treatment plants.

4.1.1 Response to submissions

The original proposal was for this part of the standard to apply to all consents in drinking-water catchments. This would have included all types of consents issued by both territorial local authorities and regional councils.

Original proposal: New consents in drinking-water catchments shall only be granted if the proposed activity does not result in drinking-water being non-potable or unwholesome following treatment.

However, some submitters said that territorial authorities should not be required to consider the effects of activities on water quality because this is outside their function. Regional councils have the function of controlling discharge to land and water, and controlling the use of land for the purpose of maintaining and enhancing water quality (section 30, RMA).

In response, this part of the standard was modified so that it applies only to activities regulated under sections 14 and 15 of the RMA (discharge and water permits). These are controlled by regional councils and unitary authorities, not territorial authorities.

The revised proposal does not address some submitters’ concerns about the effects of land use on water quality. However, many of the land-use activities regulated by territorial authorities are unlikely to result in significant effects on water quality on an individual consent basis.

There are also legal restrictions about how regulations can be written for land use compared with discharges. The RMA takes a more prescriptive approach to regulating activities that affect water: discharges are not allowed unless specifically authorised by a rule in a plan. Conversely, land uses are allowed unless a rule in a plan specifies otherwise. As a result, it would be harder to achieve certainty with land-use regulation because it would need to specify all activities that could not be undertaken. This would be a much more prescriptive approach, which could limit the flexibility of local government approaches to implementing the standard. (For example, it could require the development of detailed schedules, which would be very difficult to develop on a national basis given the wide variation of source water types and treatment plants.)

After discussion with stakeholders about the practical difficulties associated with such a regulation, the Ministry decided to restrict this part of the regulation to discharge permits and permits to take, use, dam and divert water. This restriction also addresses the concerns of some submitters that if the NES were interpreted conservatively it may restrict development in communities, particularly land uses.

The explicit reference to drinking-water catchments was also removed from the wording of the proposed NES in response to submissions. This was done to address concerns about the costs of delineating catchments, and to emphasise that decisions on consent applications should be based on a case-by-case assessment of potential effects at the abstraction point for a drinking-water treatment plant, not a mechanistic assessment based on whether or not a proposed activity is located within the boundary of a drinking-water catchment (whose boundaries could be a considerable distance from the abstraction point).

4.1.2 Population threshold

Submissions showed a range of opinions on the population threshold for the NES. Originally it was proposed that the NES should apply to community drinking-water supplies serving more than 25 people for at least 60 days of the year. However, many submitters were concerned that this threshold would lead to considerable additional work for councils. They also considered that this would mean that substantially greater areas of catchments and activities would be affected by the NES, which would result in costs being incurred for a greater number of consent applicants. They were particularly concerned about a disproportionate amount of the costs falling on small communities, and about the possible economic effects of additional regulatory requirements for small populations.

On the other hand, some submitters considered that the 25-person population threshold was appropriate in order to provide sufficient public health protection. Small water treatment plants often have the most difficulty complying with the Drinking-water Standards for New Zealand. Some submitters therefore considered that it was particularly important for the source water for these supplies to be protected, as treatment at these plants is often more basic than for larger communities.

Close to 95 percent of the New Zealand population on a reticulated water supply live in communities of 500 people or more (see Table 3). Full details on the number of community water supplies for different population bands are provided in Appendix 5.

Table 3: Distribution of New Zealand population, by community drinking-water supply zone

Population band Population Zones Number of zones % of zones complying with DWSNZ 2000
N % n % Complying with DWSNZ 2000 Not complying with DWSNZ 2000

< 25
























Total: 25-499








≥ 500








Source: Ministry of Health, Register of Drinking-Water Supplies in New Zealand, 2004.

* Figures for populations and distribution zones of less than 25 people are likely to be substantial underestimates because of a lack of information about these small community supplies.

Costs for different population thresholds

The estimated cost of applying the NES to communities of 500 people and above is $24.2 million over 20 years (see chapter 5 for further details). Setting the population threshold at 200 would mean that sources for another 298 supply zones would be included. This would extend the benefits of the NES to an additional 92,990 people. Only 40 percent of these zones currently comply with the Drinking-water Standards for New Zealand 2000 (DWSNZ 2000), so it could be argued that extending the NES to these communities would result in reducing risks to a more vulnerable sector of the population. However, it would also increase the workload for councils, and increase the national compliance costs of the NES to $54.4 million over 20 years.

For a threshold of 25 people and above, as originally proposed, the estimated cost is $200.4 million over 20 years. This is over eight times the cost of applying the standard to communities of 500 and above. Therefore, recommendations will be made to set the population threshold for the proposed NES at 500. However, proposed health drinking-water legislation would require compliance with the DWSNZ 2005 for progressively smaller populations over time, down to communities of 25 people or more. If this Bill is passed, amendments to progressively lower the population threshold for the NES may be suggested to align with the health legislation requirements.

4.1.3 Non-compliant plants

Different conditions are proposed for decisions on consent applications upstream of treatment plants that do not comply with the DWSNZ. The threshold used for assessing consent applications cannot be used for non-compliant plants, because these are currently not delivering water that is potable or wholesome.

A balance needs to be achieved between protecting source water in the catchments of plants with inadequate treatment in order to reduce the risk to public health (since these communities will be more vulnerable to contaminated source water than those with adequately functioning plants), and excessively restricting development in the catchments of water bodies with inadequate treatment plants. The test for decisions in these situations is that the proposed activity should not result in water quality becoming worse at the point of abstraction than it is at the time of the consent application.

When it comes to contaminants for which the plant is currently non-compliant (ie, levels of those determinants exceed the criteria for potability or wholesomeness after existing treatment), consents will not be granted if the activity is likely to result in the concentration of that contaminant increasing at the abstraction point. In keeping with the approach of the RMA, this means increases in concentration of contaminants at the abstraction point must be no more than minor.

For contaminants the plant is currently treating adequately, consent will not be granted for activities that will result in water becoming non-potable or unwholesome after treatment in respect of those contaminants.

4.1.4 Response to submissions

The special condition for communities with substandard drinking-water treatment plants reflects councils’ concerns about inequitable restrictions on development in catchments with inadequate treatment infrastructure. It is also intended to address council concerns that treatment plant operators may seek to prevent development in drinking-water catchments rather than spending money on upgrading their treatment facilities.

The Health (Drinking-water) Amendment Bill, if enacted, will provide an independent mechanism for upgrading inadequate treatment plants. If this legislation were in place, the special condition for communities with inadequate treatment plants could be phased out over time. This is because the health legislation would result in increased compliance with the DWSNZ for smaller communities over time. In the meantime, inclusion of the special condition is proposed to provide councils with discretion on how to manage consent applications in situations where existing drinking-water treatment facilities are inadequate.

4.2 Permitted activities

This part of the proposed standard requires regional councils to assess how permitted activities are affecting the quality of drinking-water sources. This could apply to any activity regulated by a regional council, such as discharges, water abstraction and land uses that could affect water quality.

Before including permitted activity rules in a regional plan, regional councils must:

  • undertake an assessment that considers the nature of the drinking-water sources and the nature of permitted activities in their catchments

  • be satisfied that permitted activities will not result in community drinking-water supplies being non-potable or unwholesome after existing treatment.

This part of the regulation will apply when any regional plan or part of a regional plan is prepared or reviewed.

This part of the standard will only apply to communities of 500 people or more.

4.2.1 Assessment

The proposed NES does not specify the level of detail required for the assessment. This is to be decided by individual councils at their discretion, in line with the local solutions approach of the RMA. Councils may choose to conduct assessments at a desktop level. This could be done by assessing factors such as land-use changes in a catchment over the past five to 10 years, discussing any challenges treatment plant operators may be facing with source water quality, and reviewing any existing water quality monitoring data (eg, from existing state of the environment monitoring networks). Councils could also choose to add sites to their existing monitoring networks to better characterise water sources.

Councils will not be undertaking this review in isolation. Regional councils are already required to monitor the efficiency and effectiveness of their rules (section 35(2)(b) of the RMA).

The intention is for the level of assessment to be risk-based, rather than requiring a blanket monitoring requirement for all situations.

4.2.2 Permitted activity rules

Section 70 of the RMA already requires councils to be satisfied that permitted activities will not result in specified adverse environmental effects before including these rules as permitted activities in regional plans. These effects include rendering water unsuitable for consumption by farm animals, and having significant adverse effects on aquatic life. The NES simply extends this requirement to include the effects of permitted activities on drinking-water sources.

To allow flexibility for councils and communities, the NES deliberately does not prescribe how councils should meet this requirement. Introducing or changing permitted activity rules is one possibility. Non-regulatory methods, such as riparian protection programmes, is another.

The NES also does not specify the nature of the action(s) a council must undertake if the assessment indicates that permitted activities are adversely affecting (or are likely to adversely affect) human drinking-water sources. If a council’s assessment shows that water will (or is likely to) become non-potable or unwholesome after treatment as a result of permitted activities, the council has a range of options, including:

  • tightening the conditions of the existing permitted activity rules or

  • reclassifying the relevant activity as controlled, restricted discretionary, discretionary, or prohibited or

  • increasing compliance monitoring and enforcement with existing permitted activity conditions or

  • non-regulatory tools - the council’s assessment may show that currently permitted activities are likely to degrade water quality. However, if the council can be satisfied that non-regulatory methods will prevent this degradation, or improve water quality, this could be an alternative to changing the permitted activity rule. For example, the council could support additional riparian retirement or farm management plans.

This part of the standard will not require councils to undertake a separate plan review. It is intended to be done as part of plan preparation or scheduled plan review to minimise additional work for regional councils. Councils are required to review their regional plans every 10 years (section 79(1) of the RMA). Councils are also required to monitor the efficiency and effectiveness of policies, rules or other methods in their plans at least every five years (section 35(2)(b) and (2A) of the RMA).

4.2.3 Response to submissions

Original proposal: Consent authorities will periodically assess the risks within drinking-water catchments to ensure that permitted and unregulated activities do not cause impacts beyond the performance of the affected treatment facilities.

The original notified version of the proposed standard required this action to be taken by both territorial and regional authorities. Several submitters questioned whether this was a function territorial authorities should undertake, or whether it should be performed by regional councils only. This has now been revised in response to submissions. As for the first part of the standard, this part now applies only to regional councils, in keeping with RMA responsibilities for water quality. It was considered that the majority of decisions likely to have major effects on water quality were those regulated by regional councils.

A number of submitters were concerned that this part of the standard would result in onerous monitoring requirements.

To clarify that this part of the proposed NES is not intended to require intensive monitoring, some changes to the wording were made. The phrase “drinking-water catchment” was removed, as in the first part of the NES, to make it clear that the focus of the NES is not simply whether an activity is located in a drinking-water catchment, but what effects that activity may have on a drinking-water source.

Assessments are only required before including a permitted activity rule in a plan. If plans are reviewed at the minimum of once every 10 years, then an assessment is only required once every 10 years. However, it is likely that assessments would happen at least once every five years under section 35 of the RMA.

The population threshold for this part of the standard was also changed to 500, in keeping with the reasons set out in 4.1.2 above.

4.3 Consent conditions

Consent authorities are required to:

Place conditions on consents for activities that have the potential to adversely affect the quality of a drinking-water source. These conditions will require consent holders to notify downstream water treatment plant operators and the consent authority of significant unintended events that have the potential to adversely affect water quality at the point where water is taken for a drinking-water supply.

This part of the standard applies to activities with the potential to affect community drinking-water supplies for populations of 25 people or more.

The intention of this part of the standard is to ensure that drinking-water suppliers are notified of incidents that may adversely affect their supplies, so that suppliers can take appropriate steps to ensure that safe drinking-water continues to be supplied (eg, optimising treatment processes, or shutting off intake points).

This requirement applies to all types of consents issued by both territorial authorities and regional councils. However, conditions will only need to be attached to consents that have the potential to adversely affect water quality at the abstraction point as a result of a significant unintended event. Breaches to be notified are only those with the potential to affect water quality. The judgement about whether this condition needs to be added to a consent will be made on a case-by-case basis by consent authorities, in consultation with treatment plant operators and applicants.

This part of the standard is proposed to apply to activities that could affect community drinking water supplies for 25 people or more, rather than the population threshold of 500 that applies to the rest of the standard. This is because notification of incidents is considered to be a much less onerous requirement for consent authorities and applicants than the actions required by other parts of the proposed NES, so should not impose major costs on any stakeholder group.

4.3.1 Response to submissions

Original proposal: Resource consents within drinking-water catchments will have a condition that any unauthorised activity be notified to the water supplier immediately.

Resource consents to take water for drinking will have a condition that requires appropriate action, including turning off the supply, if notified of events or activities that make the drinking-water non-potable.

The original proposal included an additional clause requiring resource consents for drinking-water takes to include a requirement to take appropriate action - including turning off the water supply - if notified of events or activities that would make drinking-water non-potable. Submitters noted that even if water is non-potable, water supplies are still required for sanitary purposes (eg, toilet flushing) and fire fighting. It would be extremely rare to require a water supply to be turned off for public health reasons. In addition, submitters pointed out that the clause duplicates the requirements of existing legislation, including those of the Health Act and Civil Defence and Emergency Management Act.

Therefore, this requirement has been removed from the revised proposal.

4.4 Provision for more stringent conditions

For a council to be more stringent than a NES, the NES must explicitly allow for this (section 43B(1) of the RMA).

Given feedback from a number of councils about the need for the NES to allow for flexibility in council approaches, it is recommended that councils be able to set more stringent conditions for protection of drinking-water sources in their region if they wish. This is seen to be particularly important for those regions where water quality is currently high.