Page 60 - Water Loss Control

42 Cha pte r F o u r

Regulations for Leakage Management
After the privatization of the water supply industry in England and Wales in 1989,
10 large regional water supply and sewerage companies were formed, which, together
with 16 statutory water supply only companies, cover the entire water supply of
England and Wales regulated by the Water Act of 1991. U.K. governance features two
primary regulatory bodies for the water industry, Ofwat and the Environment Agency
(EA). Ofwat serves as the economic regulator and the EA as the environmental regula-
tor. Each water company is required by Ofwat to produce a detailed annual report on
the volume of water supplied, consumed, and lost in each component part of the net-
work, using a standardized water balance (similar to the standard IWA water balance).
The water balance results have to be cross checked via minimum hour flow analysis of
data from DMA, which are discrete zones established to distinguish leakage events
from customer consumption.
The results of these reports are used by Ofwat to assess the performance of each
utility, to set performance targets and for intercompany comparisons. The mandatory
leakage targets set by Ofwat for each water company (in ML/d) must be met by the com-
pany in order to avoid sanctions by Ofwat.
Overall, the assessment, reporting and management of water losses are highly regu-
lated in England and Wales. This is paired with clear definitions, measures, and stan-
dards for assessing and evaluating water losses. The two regulatory agencies monitor
the performance of all water companies closely and set performance and efficiency tar-
gets driven by an economic optimum volume of leakage established for each water
company.

Leakage Management Practices
Developments of the past 20 years have resulted in a detailed understanding of the
interaction between the four fundamental leakage management practices:

• Infrastructure management
• Pressure management
• Active leakage control
• Speed and quality of repair
The understanding and accurate assessment of the economic optimum volume of
leakage is another major development and forms an integral part of a utility’s water
loss management strategy. Coherent leakage management strategies and oversight by
regulatory bodies rely upon a uniform way of assessing water losses and setting eco-
nomically and environmentally justified loss reduction targets. The main pillars of the
highly successful leakage management practices used in England and Wales are

• Improved business focus: Departments and teams were created with the sole
purpose of managing and reducing water losses to an optimum volume.
• Improved data quality: It was realized that the quality of data used for the water
audits and establishment of targets was fundamental for a successful leakage
management strategy.
• Routine calculation of water balances and performance indicators: In order to define
and refine intervention targets and measures, standardized water balances and