Information gathered from the State's water-metering programme has led Irish Water to conclude households waste less water than previously thought.
Jerry Grant, managing director of Irish Water, told the Oireachtas Committee on the future of water charges the utility was “forced to rethink” its calculations on water usage, after the metering programme revealed individual water use was about 110 litres per day, at the lower end of international comparisons.
It had previously been estimated that individuals used in excess of 140 litres per day, but metering had identified that “by far the most beneficial gain” in Irish Water’s activities was in fixing leaks “on the public side” of the pipe network.
Mr Grant told the committee on Tuesday that domestic meters measured “flow” to households “for a variety of uses”, but he said “it was a government decision to charge” for that water.
He said Irish Water provided about 1.7 billion litres of drinking water to homes and businesses a day. Of this, 600 million litres were consumed by households and 300 million litres went to “non-domestic” premises.
He said these figures were dwarfed by the 765 million litres a day which were still being lost in the public pipe network - about 45 per cent of overall water production.
The use of domestic meters had already identified leaks of 77 million litres per day on the householder’s property, which had been fixed under the utility’s free “first fix scheme”.
Already conserving water
The data the company had got from 800,000 water meters had shown most households were already conserving water - but one per cent of households used over 20 per cent of all domestic water. Five per cent of households accounted for use of one third of domestic water supplies.
Mr Grant said metering had helped the utility establish that some households had “continuous night flows”, which indicated leaks.
Some 28,000 homes had availed of the utility’s free “first fix” scheme, resulting in savings of 70 million litres of water per day.
He said about a half a billion euro had been spent on domestic water meters when the scheme was suspended, and the remaining fund of about €150 million had been redirected to invest in the network, largely in new connections.
One domestic leak under a driveway could typically see consumption rise to that of 20 households, he said.
“The information is telling us the fundamental gain is about fixing leaks,” Mr Grant said.
He added the greatest gains in water conservation over the next 15 to 20 years will not be from individual household conservation measures, but in fixing leaks and installing district meters.
Mr Grant was asked by Anti Austerity Alliance TD Paul Murphy why water meters were used to gather information on households, while district networks used other tools, from “listening sticks” to technology, to establish water flow.
Mr Grant said Irish Water could gather data from 80,000 meters in two months, collecting by the use of technology-equipped vans, whereas to send out individuals to seek access to individual properties and stopcocks would take a multiple of that time.