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Metering and management of demand on piped water systems. By Sam Kayaga (WEDC). Scope of presentation. Context Concepts of Demand-Side Management (DSM) The role of metering in DSM Pros and Cons of Metering DSM for PRODWAT? Conclusion. Context.
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Metering and management of demand on piped water systems By Sam Kayaga (WEDC)
Scope of presentation • 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
2b people (25%) will have absolute water scarcity 2.7b people (33%) will need to develop their water resources by 25% Source: http://www.iwmi.cgiar.org/home/wsmap.htm#A1 Projected water & food scarcity in 2025
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 • 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