Irish Water has defended its metering program, with the capped charges remaining for a further four years at least.
The utility has installed some 740,000 meters to date, almost three quarters of the total due to be installed, the Herald can reveal.
Currently, water bills are capped at €260 per family and €160 per single person. These limits are in place until 2019.
Last night, Irish Water dismissed the suggestion that extending the capped charge beyond 2019 negates the need for meters.
"Meters have a value right now, regardless of what you're paying. Every meter that's in the ground at the moment has a value, whether or not you are beating the caps," a spokeswoman for the troubled utility insisted.
"It helps us to identify leaks and identify lead pipes. For 40pc of people it helps them to beat the caps," she added.
Water meters have a 15-year lifespan, leading to fears that some may have just a few years left before they are finally used for billing.
The metering purpose of the meters was not their primary function however, according to the spokeswoman.
"It's not actually [the primary purpose] to be fair, a very important purpose of the meters is that it helps us to find the leaks. That's a huge part of what they do.
"You're talking about saving 37m litres of water every day, that's huge."
The utility, operating under Minister for the Environment Alan Kelly, estimates that some 70,000 customers with meters are affected by leaks that are discovered by a constant flow alarm in the meters.
Irish Water would not be drawn on speculation that the €100 conservation grant could be linked with payment of bills.
They were tasked with handing over details of customers who had registered by June to the Department of Social Protection, but they refused to say if they currently had the capability to do the same with data on who has paid their bill, if the new requirement was introduced.
"Our revenue model is based on €271m domestic revenue and that's the context that we've presented the payment figure at the end of the first billing cycle - that hasn't changed in any way," the spokeswoman said.
Meanwhile, the company is set to shell out more money on IT consultants to put together an Environmental Information System that will collect data on water quality and complaints nationwide. In a statement to the Herald, the company said that the system will be the first time that all of this data would be collated on a national scale.
Irish Water declined to say how much the new system would cost.