Irish Water has confirmed the meters being installed outside homes across the country have a lifespan of about 15 years.
With charges for usage only expected to come fully into play in 2019, confirmation of the lifespan of the metres sparked further Opposition criticism of the scheme.
Fianna Fáil says it could mean some meters will only be used for about 10 years after charges come into full effect, and the installation process will then have to start again.
The 1.2 million metres have cost about €500m to install.
Cork South Central Fianna Fáil TD Michael McGrath told the
"Beyond that and given that the meters will almost certainly have to be replaced in the following decade, it seems certain that dramatic hikes in water charges are coming down the track.
"The Government knows this and are having to put a sticking plaster over the issue in the hope it will get them beyond the general election.”