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

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%  Source: 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  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