How to find out if you have a leak

What a water leak looks like on your bill

The first place a leak shows up is your bill. An unexpected spike in usage, or a charge that does not match your normal pattern, often points to water escaping somewhere. If your operations have not changed but the bill has gone up, a leak is one of the most common causes.

Compare the cubic metres used over the last three to six months. Look for steady increases that do not match seasonal patterns, expansions, or new equipment. Check the standing charges and waste return volumes too. Wholesalers sometimes flag suspected leakage there before it shows in the consumption line. If something looks off, check whether the bill is using estimated or actual reads before raising it.

A simple meter test you can do in an hour

You can confirm a leak with your own meter and a bit of patience.

1. Turn off everything that uses water across the site: taps, machines, toilets, appliances. No water in use anywhere.
2. Find your water meter. It is usually in a chamber outside near the boundary, but can also sit inside the building.
3. Note the meter reading and the dial position.
4. Wait at least an hour, longer if you can, without using any water.
5. Check the reading again. If it has changed, water is moving through the meter while nothing is in use. That points to a leak somewhere on your supply.

Most meters also have a flow indicator (a small triangle or wheel that turns when water is moving). If it is spinning while everything is off, that confirms water is leaving the system.

4 signs of a leak inside your premises

Not every leak is visible. Some develop behind walls, under floors, or in storage areas where they go unnoticed for months. The signs are usually subtle.

Signs to look for outside the building

Outside leaks are often harder to spot but just as costly. Walk the boundary of the site every few weeks and look for:

What to do once you have confirmed a leak

Move fast. The longer it runs, the bigger the bill and the bigger the damage.

1. Work out which side of the supply the leak is on, yours or the wholesaler’s. A plumber or leak detection service can confirm if it is not obvious.
2. If the leak is on your side of the boundary, the repair is your responsibility.
3. Report it to your retailer. Provide any meter readings, photos, and dates you have recorded.
4. Get the repair done. The wholesaler may need a dated invoice from the contractor as evidence.
5. Submit before-and-after meter readings if your retailer or wholesaler asks for them.

Most wholesalers offer a leakage allowance, a partial refund of the water lost, on the condition that you have fixed the leak and provided proof. The exact rules and time windows vary by retailer, so check the process for your specific account. If your retailer is slow to handle the claim or unhelpful, a water audit can independently verify the leak history and recover backdated overcharges going up to six years.

If the experience leaves you frustrated with the retailer’s service, switching business water suppliers is straightforward. The wholesaler stays the same, there is no break in supply, just a new account.