Increasing the water allowances for adult children living at home "could be difficult", Government sources warned last night.
It is understood the Government wants to reduce or remove the full impact of charges for those children when they turn 18, but sources have warned such a move is very tricky.
The Herald has learned that two of the Government's most senior civil servants have been drafted in to find a solution to the water crisis.
The matter is to be discussed in full by the powerful Cabinet sub-committee, the Economic Management Council, when it next meets on Thursday.
This group - which comprises Taoiseach Enda Kenny Tanaiste Joan Burton, Finance Minister Michael Noonan and Public Expenditure Minister Brendan Howlin - has agreed to drive the agenda of finding a solution to the current crisis.
As a result, Department of Finance Secretary General Derek Moran and Department of Public Expenditure and Reform Secretary General Robert Watt have been tasked with finding a way to introduce a 'flat charge' until all meters are installed while ensuring EU State Aid rules are not violated.
Just 2pc of homes have families with five adults, 6pc of homes have four adults and 13pc of homes have three adults living together.
Currently, each household is entitled to 30,000 litres of 'free' water per year. Each child up to the age of 17 receives an additional 21,000 litres.
But once they turn 18 the allowance is removed.
Extending the age limit for the allowance to 18 or 19 will reduce bills by about €100 per child.
Both Mr Kenny and Ms Burton are adamant that whatever resolution is arrived at between the parties must provide "clarity and certainty" for homeowners.
There was a growing consensus across Government last night that homeowners can expect to pay the assessed charge for a longer period of time.
Meanwhile, Irish Water boss John Tierney refused to comment on a report that a private security team are providing protection outside his home.
Contacted by the Herald, Mr Tierny referred all queries to the Irish Water press office.
When the Irish Water press office was contacted a spokesman also refused to comment on the report that appeared in yesterday's Sunday World.
"We cannot comment on something to do with a private individual," said the spokesman.