By Ken Sharratt, Principal, Sharratt Water Management
Is metering effective? As of 1996, approximately 33% or 86 municipalities representing 1.3 million people had not installed water meters in southern Ontario (Chart 1). In northern Ontario, the figure is 67% or 32 municipalities comprising 227,000 people.
An opportunity to answer the question about meters is provided in the Environment Canada MUD 1996 database that covers 261 municipalities in southern Ontario and 48 in northern Ontario. These data represent 9.7 million residents served by communal water systems or 90% of the 1996 Ontario population.
Residential water use per capita was used in this analysis as it is comparable from one municipality to another and usually accounts for one half of the water use. Non-metered municipalities are those with less than 30% of the connections that are metered.
According to Chart 2, residential per capita water use is consistently lower for metered municipalities for all size ranges. In southern Ontario, residential water use in metered municipalities was 253 litres per capita compared with 345 for non-metered municipalities. The difference was 27%. The effects of metering are equally striking in northern Ontario where residential water use in metered municipalities was 291 litres per capita and that in their non-metered counterparts was 459, for a difference of 36%.
These data have shown that meters reduce residential water use but the size of the municipality also influences the amount of the saving. As shown in Chart 3, metered compared to non-metered municipalities with a population under 320,000 have a lower level of use that ranges from 28-34%. The figure is 19% for metered municipalities over 320,000 residents.
In conclusion, meters work as far as residential water use is concerned. Usage is about 30 percent lower for small and medium sized municipalities. For very large cities the figure is 20%. In northern Ontario, residential water use in metered municipalities is 36% lower.
Managers and decision makers in non-metered municipalities can assume that meters work and that water use will decline after meters are installed. This in turn may postpone the need for new capital expansion and will reduce operating costs. Accordingly, one key question can be asked. Will the capital cost savings resulting from postponement of new capacity expansion, combined with lower operating costs, offset the costs of the metering? The answer will vary according to local circumstances but the cost-efficient utility manager will wish to answer this question before considering any expansion to water or wastewater plant.
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