Smart meters enabling Tauranga householders to keep a much tighter control on water usage could be installed within the next two years.
The technology involves the remote activation of a radio signal from a transponder attached to the meter.
An advantage is that the householder can set a limit on how much they want to pay for water so that when the figure is exceeded, it triggers an alarm.
Tauranga City Council water engineers are reviewing the business case for introducing new technologies to replace the manual reading of the city's 50,000 meters.
Council water services team leader Peter Bahrs said no case would be taken to the council until it made economic sense.
In the meantime, three meter readers were enough to service the city's quarterly billing system and there were no immediate plans to replace them. New meters which were being installed were capable of being retro-fitted with new remote-reading technologies, Mr Bahrs said.
Automatic water metering was valuable in alerting the council and residents to leaks much sooner than every three months. It also allowed people to see what they were using on a day-to-day basis.
On a straight meter-reading basis, the financial benefits did not stack up to replace meter readers with the new technologies. The business case would only make sense when the benefits of tracking down leaks more rapidly were added to the equation, with the subsequent savings in water-treatment costs.
Mr Bahrs said they had put a lot of work into the new meters, including trialling 300 properties in Windermere. Instead of a meter reader taking one day to cover Windermere, a specially equipped truck driving around the same streets could do the job in 15 minutes.
The meter replacement programme would be escalated in two years, he said. This meant they needed to have a clear understanding of the business case by then so they could decide whether the council went ahead with the new meters.
They were looking at three technology packages. These were walk-by remote reading, drive-by remote reading or a fully automated system involving signals from each meter sent directly to a centralised computer. The fully automatic system was the most expensive to set up because a network of electronic collectors needed to be installed around the city.
He said they were trading off capital costs versus operational costs and working out where the balance stacked up.
"We believe we will have an answer sooner rather than later. The issue is, does it stack up?"
The council would review the business case every six months on the basis of what was happening to the water business. "If it stacks up we will move it forward, but I'm reluctant to say when exactly."
Tauranga's water-supply business
Costs $17.3 million a year to run.
Volumetric metered charge $1.73 per cubic metre.
Fixed domestic charge $27 per annum.
Water losses between treatment plants and taps 15 per cent.