A key argument for installing meters is that they force households to be more thrifty with water and fix dripping taps. Across large parts of the country, meters could hold down the steadily rising demand for water and thereby delay the need for expensive new reservoirs, boreholes and supply systems.
Nowhere is the argument stronger than in the Anglian and Southern regions, where there is greatest pressure on resources. Demand is forecast to rise by as much as a quarter by 2010. Although recent heavy rains have restored reservoir and groundwater levels after years of drought, there is no guarantee of future freedom from shortages if demand is not curtailed.
Stan Bessey, chairman of the industry's National Leakage Control Initiative, argues that it would be much cheaper to control rising demand by tackling mains leakage rather than installing meters over the next 10 to 20 years.
Mr Bessey, Bristol Water's distribution manager, says that companies with the lowest leakage levels (6 per cent) are spending about pounds 6 per household each year on detecting and plugging mains leaks. Those that spend less tend to lose more water - the maximum leakage is 36 per cent.
The cost of supplying, installing and running a water meter for a decade works out at about pounds 40 per household per year. National trials have shown that meters cut household water consumption by 10 to 20 per cent.
'Controlling leakage is certainly the most cost effective way of shaving off consumption for now,' Mr Bessey said.
Bristol Water, with a million customers, has beaten an underlying rise in demand and kept water input steady by investing in leakage control. The company has been able to delay spending pounds 20m on a new water supply plant for more than five years.