How much water is lost to leaks?
A detailed water audit and leak detection program of 47 California water utilities found an average loss of 10 percent and a range of 30 percent to less than 5 percent of the total water supplied by the utilities. The July 1997 Journal American Water Works Association cites examples of more than 45 percent leakage.

Do leaks get bigger with age?
Yes. Leaks invariably get larger with time. A small leak this year will grow to become a large leak next year, all the while losing water and causing greater damage to infrastructure and property.

Does water from leaks always rise to the surface?
No, leaks are often unseen at the surface. Non-visible leaks include leaks that percolate into the surrounding ground, leaks that enter other conveyance facilities, such as storm drains, sewers, stream channels, or old abandoned pipes.

What are the reasons to find and repair leaks?

  • Leaks get bigger with age.
  • Repairing leaks reduces growing water losses.
  • Repairing leaks with regularly scheduled maintenance reduces overtime costs of unscheduled repairs.
  • Leak repairs provide more treated, pressurized water to sell to customers.
  • Leak detection and repair can reduce power costs to deliver water and reduce chemical costs to treat water.
  • Leaks have been known to cause damage to nearby roads, other infrastructure, and sometimes buildings. Some water utilities conduct frequent leak detection and repair programs near unstable geologic areas to reduce their legal liability against expensive lawsuits.
  • Leak detection and repair improves public relations. The public appreciates seeing that its water systems are being maintained.
  • The utility gains credibility by putting its own house in order before asking the customers to conserve water.

How can I determine if there are leaks at my home or business?
Leaks from the pipes going to the building or inside the building lose water delivered through the utility meter and service.

There is one way to test if leaks exist inside the building:

  • Repair leaky faucets, showers, toilets, etc.
  • Turn off all the water using appliances (including the swimming pool, ice cube maker, water softener, etc.),
  • Look at the meter. On the dial of many meters is a small triangle which rotates if any water passes through the meter. If this device is turning, then water is flowing to an appliance or a leak.
  • You can also listen for the sound of leaks at the meter or at a hose bib.

What is Unaccounted-for-Water?
Unaccounted-for-water is a misleading term long used by the water industry. Unaccounted-for-water includes unmeasured water put to beneficial use as well as water losses form the system. Better terms distinguish between authorized unmetered uses and water losses. Authorized unmetered uses include firefighting, main flushing, process water for water treatment plants, landscaping of public areas, etc. Water losses include all water that is not identified as authorized metered water use or authorized unmetered use. Water losses are lost from the distribution system, do not produce revenue, and are unavailable for other beneficial uses. Examples of water losses are: illegal connections, accounting procedure errors, reservoir seepage and leakage, reservoir overflow, leaks, theft, evaporation, and malfunctioning distribution system controls.

Where does the water from leaks go?
Leaks often stay underground. The water may enter other underground facilities such as storm drains, sewers, electrical conduits, basements of buildings, or old abandoned pipes. Some water percolates into the surrounding ground, flows over the surface to stream channels, or evaporates.

Why do leaks produce noise?
Leaks make noise because the pressurized water forced out through a leak loses energy to the pipe wall and to the surrounding soil area. This energy creates sound waves in the audible range, which can be sensed and amplified by electronic transducers, or in some cases, by simple mechanical means. Some additional noise created by the impact of water upon soil in the area of the leak. Agitated sand and gravel can sometimes be heard striking the pipe.