Page 27 - Water Loss Control

W ater Loss Contr ol: A Topic of the Twenty-First Century 9

• 1900s: Simple mechanical geophones
• 1900s: First mechanical meter recording devices are used
• Circa 1940s: First electronic geophones and listening devices are introduced
• Circa 1970s: First computerized leak noise correlators come into play
• Circa 1980s: First battery-operated data-loggers come into play
• Circa 2000: Digital equipment and GIS-linked equipment is used for leak detection
• 2000: International Water Association issues recommendations for a standardized
water audit and performance indicators for water supply services, including
unavoidable annual real losses (UARL) and the infrastructure leakage index (ILI).
Innovations in accountability and loss control continue to occur and cost-effective tech-
nology is not usually the limiting factor in implementing a sound water loss control pro-
gram. Often the greatest challenge in creating a water-efficient system is the need to muster
the managerial and political will to launch the water loss control program into existence.

2.4 The Occurrence and Impact of Lost Water
Every water system in the world has a certain volume of real losses, and it is well
known among leakage practitioners that real losses cannot be eliminated completely,
and even in newly commissioned distribution networks there is a minimum volume of
real losses. However, it is also well known and proven that real losses can be managed
so that they stay within economic limits.
Unfortunately, it is a fact that water distribution systems have often suffered for many
years from the “out-of-sight, out-of-mind” syndrome; particularly where water has been
inexpensive and plentiful. The problems associated with water loss are numerous. High
real losses indirectly require water suppliers to extract, treat, and transport greater vol-
umes of water than their customer demand requires. The additional energy needed for
treatment and transport taxes energy-generating capabilities, which often rely upon large
quantities of water in their process. Leaks, bursts, and overflows often cause considerable
damage and inflate liability for the supplier. Most leakage finds its way into community
waste or storm water collection systems and may be treated at the local wastewater treat-
ment plant—two rounds of expensive treatment without ever providing any beneficial
use! Watersheds are taxed unnecessarily by inordinately high withdrawals. In this way,
high losses may limit additional growth in a region due to restrictions on available source
water. The full effect of leakage losses has yet to be assessed, but the economics of leakage,
discussed later in this manual, show that its impact is substantial.
Apparent losses don’t carry the physical impact that real losses impart. Instead,
they exert a significant financial effect on suppliers and customers, and distort con-
sumption data needed for water resource planning. Apparent losses represent service
rendered without payment recovered. The economic impact of apparent losses is often
relatively much greater than real losses since the apparent losses are generally valued
at the retail rate charged to customers, while the baseline cost of real losses is generally
the variable production cost (power, chemicals, and so on) for 1 unit of water. For water
suppliers the unit retail cost to customers may be 10 to 40 times the production costs for
treatment and delivery. However, for water utilities threatened by droughts and supply
shortages, or those applying demand side conservation, or those in need of new water
sources, it is appropriate to value real losses at the retail rate, since the water saved by