How do you check for a water leak at home?

Rule out a billing reason first

Before you hunt for a leak, check the bill is not the cause. Watercare suggests three quick checks.

1. Check the meter reading. The number on your meter should match, or be a little above, the reading on your latest bill.

2. Check whether the bill is actual or estimated. An actual bill after a low estimated one can be a catch-up bill.

3. Think about your usage. Guests, extra laundry or watering the garden all push the bill up.

If none of these explain it, do the meter test.

How to do the Watercare meter test

The meter test shows whether water is flowing when nothing is meant to be on. Follow these steps.

1. Find your meter. Watercare says it is usually at the front of the property near the left or right boundary, in a box with a blue or black lid.

2. Pick a time when nobody will use water, such as overnight.

3. Write down the reading. On a mechanical meter, Watercare says you only need the black numbers on the white background. On a smart meter, write down every number before and after the decimal point.

4. Do not run taps, flush toilets or use any water for four hours or more. Turn off anything that uses water on its own, such as irrigation, and do not run the dishwasher or washing machine.

5. Read the meter again. If the reading has gone up, Watercare says you are likely to have a leak.

If you have a smart meter, Watercare says a water droplet symbol showing while no water is being used means a leak.

How to do a toilet dye test

A dye test tells you whether a toilet is leaking. Toilets are one of the places Watercare suggests checking first, because a slow trickle into the bowl is easy to miss.

1. Lift the cistern lid and add a few drops of food colouring to the water in the cistern.

2. Do not flush. Wait about 30 minutes.

3. Look in the bowl. If the colour has shown up in the bowl, water is leaking from the cistern.

4. Repeat for each toilet in the house, then flush to clear the colour.

A leaking cistern usually needs a new flush valve seal or inlet valve. It is a small repair that can save a lot of water.

Signs of a hidden leak

A hidden leak often shows up as a rising bill before you see any water. Watercare suggests looking in these places.

Check for taps that will not turn off, and look for water behind the dishwasher and washing machine. Check whether the relief valve on the hot water cylinder is dripping into the gully trap. In dry weather, look for damp patches in the garden, lawn or driveway. Listen for running water when no taps, hoses or showers are on.

Other signs worth checking are a musty smell, bubbling paint or swelling skirting boards, a warm patch on a floor, and water pressure that drops for no reason.

Who is responsible for the leak?

You are responsible for leaks on your side of the water meter, and Watercare is responsible for its side. Watercare says the point of supply for water is the outlet of the meter fitting closest to your private pipe.

Watercare says a leak before the meter, towards the road, will not cause a high bill, but a leak inside the meter box may. Report a leak in the meter box, or on the street or footpath, to Watercare on (09) 442 2222, press 1. A leak after the meter is the owner’s job to fix and pay for, using a plumber. If you rent, Watercare says landlords are responsible for fixing leaks on their property, so ask yours to act quickly because you are paying for the water.

How Watercare’s leak allowance works

Watercare’s leak allowance is a credit for some of the extra water a fixed leak used. These are the terms on Watercare’s website when this guide was checked in November 2026.

You are eligible if you fixed the leak within 21 days of getting a letter or email from Watercare about a higher than normal bill, or if you fixed it before that letter arrived. Apply within three months. The terms page counts the three months from the high bill letter or email, and Watercare’s FAQs count it from when you became aware of the leak, so apply as soon as the repair is done.

The allowance covers excess water use compared with your average from your previous two meter reads. If you have not been at the property for a full year, Watercare uses a typical average daily use. Watercare aims to process applications within 10 working days, and the credit shows on your next bill. You must pay any balance owing within 21 days of Watercare’s reply.

If you have another leak within two years, you can apply again, but you must include a plumber’s invoice and the second allowance covers excess wastewater only. Business customers get a wastewater allowance only. Watercare may decline if the high use was likely from filling a pool, topping up a tank, irrigation or outdoor cleaning. Apply through MyAccount. Tenants need to be authorised tenants to apply.

When to call for leak detection

Call a plumber for leak detection when the meter test shows a leak but you cannot find it. Watercare says a good first step when you cannot locate a leak is to contact a registered plumber.

Leak detection uses tools such as pressure testing, acoustic listening and thermal imaging to find leaks under floors, inside walls or underground with as little digging as possible. If your test shows no leak but your use is still above average for a household your size, Watercare says you may qualify for a free water check through EcoMatters.

Stately Plumbing finds and repairs leaks across Auckland. We can trace a hidden leak, fix it and give you a clear invoice for your records and any leak allowance application. Call 022 159 2013.