Leak Types

photos and webpage content courtesy of Water Systems Optimization

Leaks are typically of 2 types:

Background leakage through joints in pipes and pipe fittings which are not detectable by sonic leak detection equipment, and

Infrastructure failures (i.e., main breaks, service connection leaks, valve leaks) are sub-divided into two different types:

Reported Leaks: Leaks that surface and come to the utility’s attention and are eventually repaired, usually at a sizable flow rate

Unreported Leaks: Leaks that do not surface and will not come to a utility’s attention without proactive leak detection activity, at lower flow rates but often have long durations

Leaks can occur in three different parts of the water distribution system:

  1. Water mains and appurtenances,
  2. Service connections to customers, and
  3. On customers’ premises.

Breaks on water mains are the most well known types of leaks, primarily because a water main break is usually visible, sometimes dramatically so, and disruptive to people and businesses. In addition, water main breaks often cause collateral damage to facilities and property. In some cases, water main breaks can also create significant threats to public health and safety.

From a water loss perspective, however, since water main breaks are usually treated as emergencies and repaired quickly, less water tends to actually be “lost” than “hidden” leaks that take much longer to find. Consequently, while main breaks are more dramatic, they usually do not result in as much lost water as small leaks, whether pinholes or at pipe joints, that remain undetected for months (and in many cases, for years).

 1 gpm = 525,600 gallons/year

Most leaks are found on the service connection. There are many reasons for this; but predominately, it is because this is the smallest diameter pipe and the most prone to being damaged. (Mains are buried beneath streets at larger depths and thus not as subject to being disturbed.)

The good news is that service connection leaks are fairly inexpensive to repair, and many of these types of repairs pay for themselves within a few years – sometimes less, depending on the water utility’s costs to produce or purchase water.

This webpage was funded by California utility customers under the auspices of the California Public Utilities Commission

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