Wellington Water Rates - Tiaki Wai
From 1 July 2026, Tiaki Wai became responsible for drinking water, wastewater and piped stormwater services across Wellington City, Porirua, Lower Hutt and Upper Hutt.
Wellington Water was amalgamated into the new organisation, while responsibility for water assets, funding and service delivery transferred to Tiaki Wai.
For property owners, the most visible change is billing. Water services are no longer collected as part of the Wellington City Council rates bill. Instead, owners receive a separate bill directly from Tiaki Wai.
What is happening:
Drinking water, wastewater and stormwater services will no longer be included on general rates bills
Tiaki Wai now issues quarterly bills; Wellington's first invoices were sent in late July/early August 2026, with the first payment due 1 September.
For the first year, the charging methodology will remain broadly similar to the current council approach
In the longer term the goal for Tiaki Wai is to ensure that charges for water services are consistent for similar properties that utilise comparable services.
In terms of what residential customers will actually pay, the median customer charge for 2026/27 under this Strategy is $2,281 with an average of $2,390.
For an ordinary unmetered Wellington rental, the present Tiaki Wai charges are based on fixed amounts of capital value, not the tenant’s consumption.
What this means for Wellington landlords:
For most landlords there will unfortunately be an immediate increase in property holding costs as;
Water charges likely increase by a few hundred dollars annually initially.
Further increases are signalled over coming years as infrastructure investment ramps up
Under the Residential Tenancies Act, landlords can only charge tenants for water usage where:
The property is individually metered; and
The charges relate to consumption rather than fixed infrastructure charges
Given the above, most landlords will be unable to meet the requirements for on charging water use until meters are installed at properties.
What can Wellington landlords do?
Firstly its important to compare the combined WCC and Tiaki Wai total against last year’s rates. This will give a clear indication of the full picture of any increase in costs for the year. You can do this by using the WCC Website Property Search Page
Until water meters can be installed, property owners will need to factor any additional costs into their running costs
Consideration could be given to these costs as part of rent setting/reviews however given the current softer Wellington rental market conditions it may be challenging to pass on these onto tenants in the form of rent rises
Installation of residential metering is several years away; Tiaki Wai expects more clarity on the rollout towards the end of 2026.
It is good practice to document water responsibilities, but the current statutory test is whether the cost is consumption-based and exclusively attributable to the tenant.
When will Wellington property owners receive their water bills?
Tiaki Wai water services bills are issued every three months, for approximately one quarter of the property's annual charges.
The first Wellington bills were issued in late July and early August 2026, with the first payment due on 1 September 2026. Future invoices will continue on a quarterly cycle.
How much are Wellington water charges in 2026/2027?
The median residential water services charge for a Wellington City property in 2026/2027 is approximately $2,417 per year, based on a median capital value of $930,000.
That compares with a median water-related charge of approximately $2,144 in 2025/2026, an increase of around $273 a year for the median Wellington residential property.
($2,417 - $2,144 = $273 per year)
Across Wellington, Lower Hutt, Upper Hutt and Porirua collectively, the average 2026/2027 water services bill is $2,390, 13.3% higher than the approximately $2,100 previously being collected through council rates.
The actual amount will differ between properties depending on factors including capital value and the services supplied.
How are Wellington’s water charges calculated?
For the 2026/2027 year, Tiaki Wai has largely retained the charging approach previously used by each council rather than immediately moving the whole region onto one pricing model.
For a typical unmetered Wellington residential property, charges for drinking water, wastewater and stormwater each include a fixed component plus a component based on the property's capital value.
That means most Wellington households are not currently being billed according to how many litres of water they use. Properties that already have a recognised water meter are treated differently, with drinking-water charges including a usage-based component.
Am I being charged twice? Once by the Council and once by Tiaki Wai?
No, you are not being charged twice. The water-services component has been removed from Wellington City Council's rates and is now charged separately by Tiaki Wai.
When assessing the actual impact on your property's running costs, it is therefore important to compare your new Council rates plus your Tiaki Wai charges with what you were paying previously, rather than looking at the Tiaki Wai bill in isolation.
Can a Wellington landlord pass the Tiaki Wai bill on to the tenant?
For most Wellington rental properties at present, no, not the general Tiaki Wai water-services bill.
Under the Residential Tenancies Act, landlords are responsible for property outgoings that apply regardless of whether a tenant occupies the premises, while tenants can be responsible for water costs where the supplier charges according to consumption and those costs are exclusively attributable to the tenant.
Tenancy Services says a tenant can be responsible for metered water charges where:
the property has a separate water meter;
the supplier calculates the charge based on metered water use; and
the charge can be exclusively attributed to that tenant's use.
Fixed water charges remain the landlord's responsibility.
Because most Wellington residential properties are presently charged using fixed and capital-value-based charges rather than consumption, most landlords cannot simply pass the new Tiaki Wai invoice on to their tenants.
What is my rental property already has its own water meter?
If the property has a separate meter recognised by the water supplier and Tiaki Wai is charging for actual consumption, the consumption-based portion may be recoverable from the tenant where it is exclusively attributable to their occupation.
Fixed infrastructure or property-based portions remain the landlord's responsibility.
Tenancy Services also advises that the landlord pays the water account and then seeks reimbursement from the tenant for the tenant's applicable usage charges, rather than having the supplier's account transferred into the tenant's name.
Does the tenancy agreement have to say the tenant pays for water?
It is sensible to clearly record responsibility for metered water and the meter reading in the tenancy documentation, particularly to avoid disputes.
However, the current Residential Tenancies Act focuses on whether a cost is exclusively attributable to the tenant and whether water is being charged on the basis of consumption. Tenancy Services likewise focuses on separate metering, metered usage and the ability to attribute the cost exclusively to the tenant.
Landlords should therefore avoid treating a tenancy-agreement clause by itself as sufficient authority to charge a tenant for fixed or non-metered Tiaki Wai costs.
Should landlords install their own water meters now?
There is no need to rush out and privately install a meter purely because of the new billing system. Tiaki Wai has specifically said it is not advising households to install meters individually ahead of a coordinated regional rollout.
Residential metering remains several years away, and Tiaki Wai has indicated it expects to have a clearer picture of the rollout after reviewing cost estimates towards the end of 2026.
If an owner is considering installing a private meter for billing purposes, it is essential to confirm with Tiaki Wai first whether the proposed meter would be recognised for its charging system before committing to the cost.
Can landlords increase rent to account for higher water costs?
Increased ownership costs can form part of a landlord's overall consideration when reviewing rent, but normal Residential Tenancies Act rent-increase rules still apply.
For most tenancies, rent cannot be increased until at least 12 months after the tenancy began or 12 months after the previous increase took effect, and tenants must receive at least 60 days' written notice.
For a fixed-term tenancy, an increase during the fixed term must also be permitted by the tenancy agreement. Market conditions will naturally also influence whether an increase is commercially sensible.
While many of the finer details are still being worked through, it is clear that water costs are likely to become a more significant consideration for Wellington property owners in the years ahead. Understanding how the new charging system works, planning for increased holding costs, and ensuring your tenancy agreements and property infrastructure are set up correctly will help put you in the best position as these changes are implemented.
As further information becomes available, we will continue to keep our clients informed and provide guidance on how these changes may affect their investment properties.
What should Wellington landlords do now?
The most useful first step is to look at the actual numbers for your property.
Compare your 2026/2027 Wellington City Council rates with your new Tiaki Wai charges, rather than assuming the entire Tiaki Wai invoice is a new cost.
You should also confirm whether your property already has an individual meter and, if it does, identify which part of the bill relates to actual consumption versus fixed charges.
For an unmetered rental, budget for the Tiaki Wai costs as an ownership expense for now rather than attempting to separately invoice the tenant.
Will Wellington eventually move to usage-based water charges?
That remains the direction of travel, but it is not happening immediately.
Tiaki Wai plans to move away from the current mix of council-specific and capital-value-based charging toward a more consistent regional pricing structure. It says harmonisation is expected to occur no later than 1 July 2031, with public consultation before final decisions are made.
A widespread residential-meter rollout could ultimately allow a greater proportion of water charges to reflect actual consumption. Tiaki Wai has also indicated that even after metering is introduced, bills are still likely to contain a fixed component to fund infrastructure.
For Wellington landlords, that means water costs, and how they are divided between owner and tenant, are likely to remain an area worth keeping an eye on over the next several years.