Pumping water from the Shannon to Dublin without repairing leaks “is like throwing money out a window” according to a professor of economics.
Prof Edgar Morgenroth of DCU says that Irish Water should be investing in major repairs in Dublin.
Fifty per cent of water going through the mains system in Dublin does not get to the tap, he said.
"That's extraordinary and must be one of the highest rates in the developed world," Prof Morgenroth told Newstalk Breakfast.
Prof Morgenroth was responding to recent figures from the CSO which indicated that in 2016, 37 per cent of total water use was accounted for by just 10 per cent of households.
About 75 per cent of total consumption was accounted for by 99.1 per cent of users. However, just 0.9 per cent of households used the other 25 per cent. That latter, disproportionately high figure is most likely explained by remaining customer-side leaks in the system by the end of 2016, sources have said.
“The level of water going through the pipes in some houses would be enough to fill a swimming pool . . . daily,” he said. “That has to be a major leak.”
He said leaks can happen for a variety of reasons, but that metering helps identify them. If a leak is in a private house, then it is straightforward to “knock on the door and say fix it”.
The high rate of some of the leaks is indicative of major problems which would require replacement of networks of pipes, some of which are 100 years old, he said.
Replacing long sections of pipe is the best way money could be spent, according to Prof Morgenroth.
Without repairs water is going to continue to leak, he said.