How a Leak Detector Finds a Leak in Your Stock Water System

Why Stock Water Leaks Stay Hidden for So Long

A burst poly line is obvious. A trough runs dry, stock are bellowing at an empty trough, and somebody notices within a day. But most stock water leaks are not dramatic. They are a slow bleed from a float valve that has worn and no longer seals, a joint that has worked loose in a long paddock line, a fitting nicked by a grader or livestock, or a tank overflow pipe running more than it should. These small leaks can run for weeks or months in a paddock nobody drives past often, quietly costing thousands of litres and a real dent in pump or bore running costs before anyone realises.

The reason they stay hidden is simple: a stock water leak usually produces no obvious surface water in dry, sandy, or well-drained country, and troughs are often spread across the property, out of sight of the house or shed. Unless a tank actually runs empty, there is often no signal at all that something is wrong.

A leak detector changes this. It is a flow meter installed at a key point in your stock water system — feeding a tank, a trough line, or straight off a bore or pump — that measures how much water is moving through that point. Over time that data tells you exactly what normal looks like for your herd, mob, or property. Any deviation from normal is a signal worth investigating.

Understanding Your Baseline

The foundation of leak detection with a leak detector is establishing a baseline: what does normal daily flow look like feeding a given tank or trough line on your property? This takes a week or two of monitored data to establish, but once you have it, every subsequent day can be compared against it.

Your baseline should account for herd size and season — a mob of cattle in a 40°C summer will pull far more water through a trough line than the same mob in a mild autumn — and for how many head are actually in that paddock at a given time. Some producers keep a simple log: date, approximate head count, and any notable observations. Once you have a couple of weeks logged across a few different conditions, patterns become clear.

In automated monitoring systems, this baseline tracking happens continuously in the background. The BushLinx® platform logs flow data over time and displays it graphically, making it straightforward to see whether this week's water use on a line is tracking normally or has crept up for no obvious reason.

The Overnight Test: The Most Reliable Leak Indicator

Animals do not generally drink at night, which means overnight is the closest thing a stock water system has to the zero baseline an irrigation system gets when it is switched off. If your leak detector is recording meaningful flow between, say, 10pm and 6am, that flow has to be going somewhere other than a thirsty animal.

This works because it removes almost all legitimate water use from the equation. During the day, a moderate leak is hidden within normal drinking demand across the mob. Overnight, that same leak is close to 100 per cent of the recorded flow and is immediately visible.

A float valve that has stopped sealing properly, or a trough that is overflowing continuously, will typically show up as a flow reading that never drops to near zero overnight — it just runs, day and night, regardless of whether stock are actually drinking. Even a relatively small constant leak of 200 litres per hour adds up to almost 5,000 litres a day, silently, on a line nobody is watching.

What Different Leaks Look Like in Flow Data

A worn float valve or ballcock that no longer shuts off fully typically shows up as a small but constant flow reading that barely changes whether stock are at the trough or not — the tell-tale sign of an overflowing trough rather than a genuine leak in the line, though the water cost is the same either way.

A pinhole leak or a slow-seeping joint in a poly line typically shows up as a small, steady flow reading — say 50 to 200 litres per hour — that persists through the low-use window and does not change much night to night. If you cannot find anything visible above ground, the leak is likely underground, and you will need to walk the line looking for a green, boggy, or unusually soft patch of ground.

A pump or pressure system with a failing seal or relief valve can show up as cyclical flow readings — pressure builds, bleeds off through the leak, the pump kicks in to compensate, and the cycle repeats. This creates a distinctive on-off pattern in the flow data rather than one steady low reading.

Comparing Flow Volume to Tank Level Data

One of the most powerful combinations in stock water management is pairing leak detector flow data with tank level monitor data. The leak detector tells you how much water left the source. The tank level monitor tells you how much actually ended up — or stayed — in the tank. When those two figures are consistently mismatched, the difference is going somewhere it should not be.

That discrepancy can point to a leak in the supply line before the tank, a trough float valve stuck open downstream, or a tank overflow pipe running more than expected. Each of those problems has a different fix, but comparing flow data against tank level data is what surfaces the problem in the first place — often before a tank runs low enough to actually put stock at risk.

BushLinx® supports both flow monitoring and tank level monitoring in the same platform, making this kind of cross-comparison straightforward. Bringing the data together in one view means a problem that might not be obvious in either dataset alone becomes immediately visible when you are looking at both, and SMS alerts mean you find out about it from your phone, not from a dry trough and unhappy stock.