Newsletter and Technical Publications
<Proceedings of the International Symposium on Efficient Water Use in Urban
Areas
- Innovative Ways of Finding Water for Cities ->
E. Session 5: Leakage Control and the Reduction of
Unaccounted-for Water (UFW)
Moderator: Ms. Cristianne Chauvet-Urquidi, Mexico City Water Commission,
Mexico
Rapporteur: Dr. Antonio L. Fernandez, United Nations Centre for Regional
Development
Presenters:
(1) Mr. Jose Augusto Hueb, Sanitary Engineer, World Health Organisation
(2) Mr. Richard G. Sykes, Manager, Water Treatment and Distribution, East Bay
Municipal Utility District, USA
(3) Mr. Alexander Rizzo, Operations Engineer, Malta Water Services Corporation,
Malta
Three presentations were made regarding leakage control and the recovery of
UFW.
The World Health Organisation (WHO) representative made a comprehensive
proposal focusing on managerial approaches for reengineering traditional ways
of providing water services, both public and private. It was noted that these
services should not only be cost effective through water recovery, but also
capable of directing the newly available water to people in underserviced urban
areas, who are more vulnerable to water-related health risks.
A more specific example of managing UFW was provided by the representative of
a public municipal utility. This perspective addressed the need for new
approaches for water loss reduction in terms of the types of leaks related to
pipe material performance, age, and other technical considerations, as well as
labour costs, with a view to more cost-effective management.
Another example of UFW and leakage control was presented, illustrating a
planned and structured approach to protect limited availability of water
resources.
Key Points Presented:
- Worldwide, the population unserved with a safe water supply and sanitation
was almost the same in 1990 as in 1980.
- Basic elements that affect the operation of water systems include:
- - inadequate data on operation and maintenance (O&M)
- - the need for broad and comprehensive decision-making
- - inefficient use of funds
- - poor management
- - inappropriate system design
- - political interference
- - inadequate policies and legal framework
- - accountability – responsibilities
- - economic leakage level setting (where marginal cost of leakage control =
marginal cost of water being lost)
- - environmental constraints
- - R&D
- Unaccounted-for water (UFW) in cities in the developing world has been
reported to be more than 50 per cent, to as high as 70 per cent of the total
water supplied. Any reduction of UFW can help in expanding water supply
coverage; thereby reducing deaths resulting from unsafe water and related
poor sanitation practices.
- Definitions of UFW differ depending on the needs of the particular city,
country, professional group, etc. A usual definition applicable to
localities where metering is practised, is production minus metered use. The
term “UFW” refers basically to water losses and leaks not accounted for,
including distribution losses, illegal connections and water theft.
- Goals and targets (long-term and short-term) must be set with respect to
reducing water losses. Moving targets must be avoided. It is best to set
targets that can be measured and compared against international benchmarks
such as cubic m/hr or cubic m/km/day, and not a percentage. The targets
should also be controllable by the facility owner or regulatory authority.
This is particularly important when outsourcing services for dealing with
UFW.
- A zoning scheme that uses the hydrological unit concept as practised in
Malta is an example of a decentralised approach in which analysis of UFW can
be done effectively.
- Corporate commitment, choice of adequate equipment and instrumentation are
all important.
- Ideally, programmes dealing with water losses should be undertaken by
water authorities or companies. Leakage control is only one component of
efficient water use; other components include applied network surveys,
leakage detection, meter testing, and other initiatives.
- Leakage control for both visible and invisible leakage is essential.
Controlling leakage requires a mix of passive control and consumption
monitoring. A balance between preventive and corrective maintenance is
essential to minimise costs.
- Baseline data are necessary for future comparisons. The information can be
stored in the form of spreadsheets and augmented through the use of
geographic information systems (GIS).
- It is important to involve users, and inform them about the water
company/utility and about technologies and approaches that save water.
- Issues pertaining to UFW arise from the following:
- - The water supply system
- - Water sources and water shortages
- - Location and geographical characteristics (inland, island, etc.)
- - Water rich or water poor
- - Age of pipelines
- - Universal metering vs. no metering
- - Institutional and organisational frameworks and commitments
- - Water price
- - Cost of labour (particularly for pipeline rehabilitation and
replacement)
- - Profile, composition and characteristics of consumers and their
consumption patterns.
Session Recommendations:
- Water authorities and companies need to be supported by effective
laws and regulations. Legal barriers must be overcome to ensure that
measures and programmes for preventing and controlling UFW are
implementable.
- To facilitate the transfer of know-how, guidance documents and
training packages must be made available to water authorities and
companies.
- Training the staff of water authorities and companies should be
undertaken to improve the quality of service to users and to help
develop positive corporate attitudes.
- The implementation of sound operational practices by water companies
and authorities may require reengineering and new institutional
frameworks. Information on actual cases should be disseminated widely
to learn from these experiences.
- Information and education of decision makers and citizens must be
given due emphasis.
- Decentralising water systems through zoning levels or hierarchies
based on hydrological and water balance principles should be examined
further to ensure that appropriate measures are implemented in a
manner which is responsive to local conditions.
- Government must play a leading role to ensure that safe water is
made available to the population. In so doing, closer links between
water supply, environmental sanitation and health must be established,
taking the perspective of users into account.
- The involvement of the private sector in the provision of water
services is welcome; however governments must provide good controls
and regulations. Controls are particularly needed regarding
concessions and the purchase of assets.
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