Transcript Metering and management of demand on piped water systems

Metering and management of
demand on piped water systems
By Sam Kayaga (WEDC)
Scope of presentation
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Context
Concepts of Demand-Side Management (DSM)
The role of metering in DSM
Pros and Cons of Metering
DSM for PRODWAT?
Conclusion
Context
 Household water use should conform to
Integrated Resource Planning (IRP).
 It should be managed in a way that satisfies
multiple objectives for the water resource use and
Conform to development objectives
Minimise economic costs of delivering the service
Contribute to reliability & sustainability of supply
Promote equity considerations
Minimise environmental impacts
Treat water as an economic, finite resource
Projected water & food scarcity in 2025
 2b people
(25%) will
have absolute
water scarcity
 2.7b people
(33%) will need
to develop their
water
resources by
25%
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Source:
http://www.iwmi.c
giar.org/home/ws
map.htm#A1
What is Demand Side Management (DSM)?
 DSM is part of IRP, and corrects the traditional
overemphasis on supply-side planning
 DSM is a coordinated set of measures to improve
energy, water or other environmental services by
inducing changes at the point of consumption
 DSM programs involve a systematic effort to
manage the amount and/or timing of water
demanded by customers
Common DSM Instruments
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Rationing, by limiting time of use and/or quantity
Retrofitting of water faucets e.g. low-flush toilets
Education and advertising campaigns
Pressure reduction at the customer end
Financial incentives: rebates, subsidised retrofits
Encouragement and training regarding rainwater
harvesting, recycling and/or wastewater reuse
 Moral persuasion – calls for voluntary reductions
 Pricing instruments through tariff structures
Metering for DSM
 Metering of service connections is a prerequisite if some
DSM tools are to be applied
 Metering encourages water conservation and minimises
wastage, e.g.
 In Canada, households on a flat rate used ~ 474 l/c/d in
2001, which was 74% higher than those metered
(Environment Canada, 2004).
 Metering also enables
 Pricing water by volume used, i.e. promoting equitable use
 Full-cost pricing for water
 Accurate quantification of non-revenue water
 Evening out the peak loads
Problems with metering (1)
 Results into higher operational costs, in terms of
 Capital and installation costs
 Meter reading, bill processing and distribution
 Maintenance costs
 Could provide inaccurate readings due to
technical faults
 Meters could be tampered with (common in
developing countries)
 Customer acceptance of metering
Problems with metering (2)
 Other practical and operational matters
 Meter location –accessibility to demand & supply
 Meter installation in multi-occupied properties
 Inaccurate readings from some types of meters for
intermittent water supply
 Changing meter technology to allow greater accuracy
 Tariff issues
 The tariff structure will of necessity be more complex
 There is need to balance between fixed and variable costs
PRODWAT and DSM (1)
 If well designed, the objectives of DSM could reinforce
those of PRODWAT
 The supply-fix approach has often favoured affluent
consumers over the poor
 The water saved through DSM could be channelled to
disadvantaged households, to cater for health and
productive uses
 Metering could ensure that those using more water for
production uses pay more
 Education and training under DSM could have differentiated
messages to encourage household productive use of water
PRODWAT and DSM (2)
 Metering and volumetric charges could promote
the ethos of PRODWAT, through increasing block
tariffs.
 Increasing Block Tariff could be designed to cater
for differentiated use of water in the household,
e.g.
 Lifeline block for drinking, cooking, dish-washing,
garment washing, house-cleaning
 A block for productive uses of water around the
households, which could be at par with luxury uses
such as swimming pool
Conclusion
 DSM is not in conflict with the objectives of
PRODWAT
 Both concepts could work together to contribute to
sustainable urban water management