NZ Drinking Water Requirements & Legislation
Tank Water, Bore Water & Private Water Supplies in New Zealand
If your home, rental property, farm, lifestyle block or business relies on a private water supply, it is important to understand the requirements that apply to your water system; and, most importantly, make sure the water you provide is safe to drink.
New Zealand's drinking-water requirements have changed significantly in recent years. The rules now distinguish between domestic self-supplies, shared domestic supplies, commercial and community supplies, and larger drinking-water networks.
WTS can help you understand your water supply, test your water and identify practical improvements such as tank cleaning, filtration, UV disinfection and water-treatment upgrades.
How does the law apply to my private water supply?
The answer depends on what the water is used for, who uses it and how many people are supplied.
A private rainwater tank supplying a single household is treated differently from a bore supplying a farm workplace, café, accommodation business, community facility or multiple properties.
The important distinction
Under the current Water Services Act framework:
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A domestic self-supply serving 25 people or fewer for domestic use does not need to register with Taumata Arowai.
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A shared domestic supply serving 25 people or fewer can also fall outside the specific supplier requirements of the Water Services Act.
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A supply serving a commercial, public or community facility can have legal obligations even when it supplies 25 people or fewer.
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Supplies serving 26 or more people generally fall within the drinking-water supplier framework.
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New drinking-water supplies established after 15 November 2021 must be registered and meet the relevant legal requirements from establishment.
The rules can be more complicated for farms, businesses, accommodation providers, community facilities and supplies serving multiple buildings or properties.
Not sure which category your property falls into?
WTS can assess your existing water supply and help identify the water-quality, treatment and maintenance requirements that should be considered.
1 hr 30 min
Price from $185
1 hr 30 min
Price from $490
What is a domestic self-supply?
A domestic self-supply is a drinking-water supply serving a single domestic dwelling or household. For example: -A house supplied by a rainwater tank -A rural home supplied by a bore -A lifestyle property using a private spring -A holiday home supplied by rainwater -A rental house supplied by a private water supply Domestic self-supplies serving 25 people or fewer do not need to register with Taumata Arowai and do not have specific supplier responsibilities under the Water Services Act 2021. However, that does not mean that water quality should be ignored. Taumata Arowai recommends that domestic self-supplies are managed to protect the health of the people drinking the water. For homeowners and landlords, practical measures should include: -Using a UV Disinfection System -Using appropriate chemical and mechanical filtration -Keeping the roof catchment and gutters clean -Preventing contamination entering the tank -Regularly inspecting and cleaning the tank -Protecting the tank from insects, animals and other contamination -Testing drinking water periodically -Maintaining pumps, filters and treatment equipment -Investigating changes in taste, smell, colour or water clarity
What are the requirements for supplies serving more than 25 people?
Drinking-water supplies serving larger populations have additional responsibilities. The exact requirements depend on the type of supply, the number of people supplied, whether the supply is networked, the source of the water and how the water is treated. Depending on the supply, requirements can include: -Registration with Taumata Arowai -Managing risks to drinking water -Water treatment -Drinking-water quality monitoring -Testing -Record keeping -Drinking-water safety planning -Meeting applicable Drinking Water Quality Assurance Rules or an Acceptable Solution -Taking action when drinking water may be unsafe Existing unregistered supplies have additional transition time. Taumata Arowai currently allows existing supplies to register by November 2028 and to meet the full legal responsibilities by November 2030. The fundamental responsibility to supply safe drinking water already applies. New drinking-water supplies established after 15 November 2021 have different requirements and must be registered and comply from establishment.
Drinking Water Quality Assurance Rules
New Zealand's drinking-water regulatory framework continues to evolve.
The Water Services (Drinking Water Quality Assurance) Rules 2026 were made in June 2026 and come into force on 1 July 2027.
The new Rules establish requirements according to the type, scale and risk of the drinking-water supply.
They include categories such as:
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Very small community supplies
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Small networked supplies
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Medium networked supplies
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Large networked supplies
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Self-supplied buildings
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Downstream supplies
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Water carriers
The requirements are therefore not the same for every private water supply.
What does this mean for private water-supply owners?
If you operate a drinking-water supply that falls within the regulated framework, it is worth planning ahead rather than waiting until the compliance deadlines approach.
Your existing infrastructure may need to be assessed for:
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Source-water risks
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Storage
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Filtration
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UV disinfection
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Other treatment
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Distribution
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Monitoring
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Testing
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Maintenance
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Documentation
WTS can help assess the practical water-treatment and infrastructure side of your system.
Building Code requirements for water supplies
Drinking-water legislation is not the only set of requirements that can apply to a private water system.
The New Zealand Building Code Clause G12 – Water Supplies addresses the safe supply, storage, reticulation and delivery of water in buildings.
G12 applies to buildings provided with water outlets, sanitary fixtures or sanitary appliances and requires safe and adequate water supplies.
This is particularly relevant when:
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Building a new home
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Installing a new private water supply
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Upgrading an existing water system
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Installing water treatment
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Replacing plumbing components
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Connecting tank or bore water to a building
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Designing a rural or lifestyle property water system
Important 2026 change: lead-free plumbing products
There has been an important update to G12/AS1 in 2026.
From 2 May 2026, the previous transition arrangement ended and the updated G12/AS1 requirements apply where that Acceptable Solution is being used.
For copper-alloy products used in contact with drinking water, the updated requirements include:
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Maximum lead content of 0.25%
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Dezincification-resistant copper alloy requirements for relevant components subject to hydrostatic pressure
The requirements apply to products such as certain:
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Pipe fittings
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Valves
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Taps
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Mixers
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Water heaters
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Water meters
This is particularly important when specifying components for new or upgraded potable-water systems.
Building work and plumbing work must still comply with the Building Code even where a building consent is not required.
Rainwater tanks and drinking water
Rainwater is widely used throughout rural Waikato and New Zealand for household drinking water.
However, rainwater collected from a roof can be exposed to a range of contaminants before it reaches the tank.
Potential sources include:
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Bird and animal droppings
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Organic debris
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Dust
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Leaves
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Roof contaminants
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Atmospheric contamination
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Sediment
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Bacteria and other microorganisms
A tank can also accumulate sediment and organic material over time.
This means that clear-looking water is not necessarily safe drinking water.
A well-designed rainwater system should consider the complete pathway:
Roof → Gutters → Pre-filtration → Tank → Pump → Filtration → UV/treatment → Household
WTS can assess your existing system and recommend practical improvements based on the water source, property and intended use.
Bore water and private groundwater supplies
Bore water can look perfectly clean while containing contaminants that cannot be detected by sight, smell or taste.
Depending on the geology and location, groundwater may contain issues such as:
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E. coli and other microorganisms
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Iron
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Manganese
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Hardness
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pH imbalance
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Nitrates
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Other dissolved minerals or chemical contaminants
The appropriate treatment depends on the actual water quality.
For this reason, we recommend testing before selecting treatment equipment rather than automatically installing a particular filter or UV system.
WTS can arrange laboratory water testing and use the results to recommend an appropriate treatment solution.
Water testing
The most useful first step when you're concerned about water quality is often to test the water.
WTS provides drinking-water testing for:
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Rainwater tanks
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Bore water
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Rural properties
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Lifestyle blocks
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New homes
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Rental properties
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Property purchases
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Farms
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Commercial premises
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Private water supplies
Testing can investigate microbial, chemical and particulate water-quality issues.
Our testing service includes:
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Water sample collection
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Laboratory testing
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Laboratory reporting
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Interpretation of results
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Practical recommendations where issues are identified
Testing can be particularly useful if you notice:
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A change in taste
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A change in smell
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Cloudiness
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Discolouration
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Sediment
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Recurrent illness concerns
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Problems with an existing treatment system
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Changes following heavy rainfall
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Changes after a tank has been disturbed or cleaned
1 hr 30 min
Price from $490
HOW WTS CAN HELP
WATER TESTING
Find out what's actually in your water, with potable water testing from a registered laboratory.
TANK CLEANING
Remove accumulated sediment and contamination from your drinking-water tank.
FILTRATION
Choose appropriate filtration based on your water source, water supply system and test results.
UV TREATMENT
Protect drinking water against microbiological contamination with an appropriately designed UV system.
WATER SYSTEM ASSESSMENTS
We can assess your tank, pump, filtration, UV and water-treatment system and identify areas that may need attention.
WATER TREATMENT PRODUCTS
Shop pumps, filtration, UV systems and water-treatment equipment through the WTS online store.
Frequently asked questions
Important information
This page provides general information about New Zealand drinking-water, water-supply and Building Code requirements. It is intended as a practical guide and is not legal advice.
Requirements can vary depending on the type of water supply, number of people supplied, property use, source of water and system configuration.
Regulations and technical requirements can change. For current regulatory requirements, refer to the relevant information published by Taumata Arowai – the Water Services Authority and MBIE.
https://www.taumataarowai.govt.nz/about-us/legislation
https://www.building.govt.nz/building-code-compliance/g-services-and-facilities/g12-water-supplies
Page last reviewed: September 2026