Hidden Water Leak Blew Out Your Bill? Here's Who Actually Pays in NZ

The short version: a leak does not automatically become the tenant's bill. A tenant can only be charged for water they actually used under s.39 of the Residential Tenancies Act, and a spike caused by a fault in the property's own plumbing is a landlord maintenance issue, not tenant usage. Most councils and water providers run a leak allowance scheme that credits back the excess once the leak is fixed within their deadline, which is why the Carterton case that prompted this article ended with the council being asked to waive an $18,000 bill rather than the tenant or landlord simply wearing it.

I split water bills by hand across my own Auckland properties, and the one call landlords get wrong most often is assuming a huge bill means someone did something wrong. Usually it means a pipe failed. Here is how to work out who actually owes what, and the exact steps to get a leak-driven bill reduced before you pay a cent of it. For the underlying rule on what you can charge a tenant day to day, see my guide to water charges in NZ rentals.

What Happened in the Carterton Case?

In 2026 a commercial property in Carterton's Waingawa industrial area used more than 20 times its normal quarterly water volume, from 269 units to 5,571 units between February and June, after a leak developed on the property. Repairs were carried out in May, but the leak alarm at the meter kept showing active even after usage returned to normal in June and July. Carterton District Council staff recommended waiving the bill, with a condition that no further waivers would be granted while the alarm stayed active (Scoop News). It is a commercial case, not residential, but the same mechanism applies to rentals: a genuine, promptly fixed leak is treated differently from ordinary usage.

Who Is Responsible for a Leak on a Rental Property?

Under s.45 of the Residential Tenancies Act, the landlord must maintain the premises in a reasonable state of repair, and that includes the plumbing (Tenancy Services - maintaining the property). If a pipe, cylinder, or fitting fails through age or a fault, fixing it is the landlord's job and cost, full stop. It does not matter whether the tenant is the one who happened to notice the puddle.

Who pays for the water that leaked out is a separate question from who pays to fix the leak, and this is where landlords go wrong. If the fault was in something outside the tenant's control, the extra usage is not something you can fairly on-charge, even if your tenancy agreement lets you pass on metered water. If the tenant caused the fault themselves, for example by damaging a fitting, that is a different conversation entirely and may be recoverable as damage rather than usage.

How Do You Get a Leak-Driven Water Bill Reduced?

Most councils and water providers run some version of a leak allowance. Watercare's version, the largest provider by customer numbers, works like this:

1. Fix the leak within 21 days of being notified of unusually high usage, or before you are notified at all
2. Apply within three months of the higher-bill notice
3. The credit is calculated against your average usage from the previous two meter reads
4. You cannot claim it twice for the same property within two years, and it will not be granted if the high use looks like pool-filling, irrigation, or a tank top-up rather than a leak

(Watercare - apply for a leak allowance). Other councils and water providers around NZ run equivalent schemes under different names; check your own provider's website the moment a bill looks wrong, because most of these have a hard deadline that starts running from the date of the notice, not the date you get around to reading it.

What Should a Landlord Do the Moment a Water Bill Looks Wrong?

1. Check the meter yourself or send a plumber - most meters have a small leak indicator (a spinning dial or triangle) that moves even when every tap in the property is off
2. Get the leak fixed immediately; the clock on most leak allowance schemes is already running
3. Keep the plumber's invoice and any before and after meter readings as evidence for your application
4. Apply to your water provider for the leak allowance before the application window closes
5. Do not on-charge the spike to your tenant while the allowance application is still open, so you are not asking them to repay money the provider later credits back

What If Your Water Provider Doesn't Offer a Leak Allowance?

Watercare's landlord and property manager guidance is explicit that the property owner remains responsible for the account regardless of any private arrangement with a tenant, and that the service cannot be disconnected over a dispute (Watercare - landlords and property managers FAQs). If your provider has no formal allowance policy, put the request in writing anyway, reference the repair invoice and meter readings, and ask for the excess to be waived on the same grounds. A documented request, even without a named policy, is usually a stronger position than paying quietly and hoping it does not happen again.

Keeping the repair invoice, the before-and-after meter readings, and the provider's written response together in one place is exactly the kind of thing that gets lost across a busy year of managing a rental. RentManager attaches documents straight to the property and tenancy record, so if a tenant or the Tribunal ever asks what happened with that bill, you have the full trail in one click.