Warehouse water bill gone up? How to check for a hidden leak
A warehouse bill that climbs while the site is doing the same work points to a leak on the supply pipe under the yard, a leak inside the building, or several small losses in welfare blocks, wash bays and equipment feeds. You can narrow it down with the meter, even on a site that never fully shuts.
If the site never shuts, use a quiet window
The simplest meter test needs a period when nothing should be using water, and a warehouse running shifts may never have one. Pick the quietest point instead, such as a shift change or a weekend morning, and ask supervisors to stop using taps, hoses and wash-down points for half an hour. If that is not possible, the stopcock test below still works, and areas can be isolated one at a time.
Find the meter and every branch
On most industrial estates the meter is in a chamber near the site entrance, in the verge or under a cover in the car park. The internal stopcock is where the main enters the building, often in the plant room, the welfare block or near the loading bay. Larger sites can have sub-meters on a wash bay, an office block or a second unit, and each can be read the same way. If the site has a separate fire main or sprinkler supply, ask maintenance how it is fed before assuming it plays no part.
Read the meter twice
During the quiet window, note the meter reading including the red dials or the last digits, then read it again thirty minutes later. Many meters have a small disc or star that turns whenever water flows. If it is turning while nobody is using water, it is going somewhere.
Where the supply has an automatic meter reader, your water retailer may be able to provide interval data. A night-time line that never drops towards zero tells you the same as a turning dial.
Inside the building or under the yard?
Shut the internal stopcock fully and watch the meter for ten minutes.
| With the stopcock shut | What it points to | Next step |
|---|---|---|
| The meter stops | The loss is inside the building, in pipework, cisterns, plant or the feeds to equipment. | Check where water goes on the site, area by area. |
| The meter keeps moving | The supply pipe between the meter and the stopcock is leaking, usually under the yard or car park. | Read about leaks under the yard below. Finding it needs listening or tracer-gas equipment. |
| The meter slows but keeps moving | There may be a loss on both sides, or the stopcock may not shut off fully. | Get the stopcock checked, then repeat the test. |
Where water goes on an industrial site
Rising bills on a working site often come from several small losses rather than one burst. Go through the areas that use water:
- Welfare blocks. Cisterns that pass water into the pan or overflow, and cistern-fed urinals that flush on a timer unless a flush control is fitted and working.
- Wash bays and yard taps. A hose left running, an outside tap nobody turned off, or a vehicle wash with a valve that passes.
- Feeds to machinery and wash-down points. A solenoid valve that no longer closes, or a slow leak where a feed drops down a column.
- Tanks and boosters. A storage tank that keeps refilling because its float valve does not shut, or a booster pump that runs with every outlet closed.
- Heating plant. A pressurisation unit topping up the system daily, or a safety valve dripping into its tundish, the small open funnel below it.
- Exposed pipework. Pipes in unheated parts of the building can split in freezing weather, so check runs along walls and roof spaces after a cold spell.
Isolate one area at a time and read the meter after each. The area where the meter slows is the one to look at more closely.
Leaks under the yard
If the meter moves with the stopcock shut, the supply pipe is leaking between the meter and the building, and on an industrial site that run can be long. Look for water coming up through joints in the tarmac, concrete that stays damp or grass that stays green in dry weather. A yard surfaced for heavy vehicles can hide a leak for months, so a lack of visible water proves little. The pipe is traced with acoustic listening, leak-noise correlation and tracer gas, then exposed with a targeted excavation. How ADI investigates water mains and yard supplies.
What a steady leak adds up to
Meters read in cubic metres, and each cubic metre is 1,000 litres. A leak of one litre a minute is 1,440 litres a day, or more than 43 cubic metres over a 30-day month, regardless of how busy the site is.
When to call
Call if the meter keeps moving with everything you can find switched off, if it moves with the stopcock shut, or if you would rather an engineer ran the tests. Tell the office what you found and when the site can be quiet; it helps plan the visit around your operations.