The Minister for the Environment, Phil Hogan, has told the Dáil Environment Committee that his department spent almost €16m last year in relation to the changeover of responsibility for water services from the 34 local authorities to Irish Water.
This is separate to the company's budget of €180m of which €85m will be spent on external service consultants.
The Minister said €7m had been spent surveying where water metres should be located and road opening.
Of the €15.76m, €5.7m was spent on water services transition office in each local authorities and a national office.
He said €7m was spent on a survey of where the meters should be located.
Minister Hogan said that €628,000 was spent on programme management office in the department.
€760,000 was spent on the regulator, €328,000 was spent on staff engineering services and €321,000 was spent on additional staff.
€179,000 was spent on a PricewaterhouseCoopers report.
The Minister also told the committee he has "full confidence" in John Tierney as Managing Director of Irish Water.
Minister Hogan pointed out to the Independent Deputy that Mr Tierney would be reporting to a "full board" at Irish Water.
Mr Hogan was asked if there was cabinet approval for €500m loan from the National Pension reserve fund for the set up costs of Irish water and the metering programme.
In a statement, the department said the “Budget for the establishment of Irish Water is being funded by a commercial loan from the National Pensions Reserve Fund.”
It adds that the overall budget was outlined as part of the funding issues considered by the Economic Management Council and the Water Reform sub-committee of the Cabinet Committee on Economic Infrastructure.
“The combined consent of the Minister for the Environment, Community and Local Government, the Minister for Communications, Energy and Natural Resources, the Minister for Finance and the Minister for Public Expenditure and Reform was required to allow Irish Water enter into the loan from the National Pensions Reserve Fund”.
Earlier, Taoiseach Kenny said Irish Water is a major project.
He said that there cannot be a situation where thousands of people have to boil water every day and where 40% of water is leaking out of the system.
The Taoiseach expressed confidence in the leadership of John Tierney as CEO of Irish Water.
Speaking as he arrived for this morning's Cabinet meeting, the Mr Kenny said he has every confidence that Mr Tierney will do the job as expected.
He said Mr Tierney will deal with any issues that arise when he appears before the Public Accounts Committee.
Leader's Questions in Dáil
Mr Kenny faced further questions about Irish Water during Leaders' Questions in the Dáil this afternoon.
Fianna Fáil leader Micheál Martin asked Mr Kenny about the establishment costs of Irish Water and the payment of bonuses to staff.
Mr Kenny explained the background to why Bord Gáis was selected to put Irish Water in place.
He said Bord Gáis pays performance pay to employees.
Mr Kenny said there is a pay freeze until 2016 and the performance pay is based on achieving a series of targets.
He said he has asked Minister for the Environment Phil Hogan to obtain a list of criteria that is used to determine bonuses.
Mr Hogan also has said he has "full confidence" in Mr Tierney.
He was responding to the Independent TD Luke 'Ming' Flanagan at a meeting of the Oireachtas Committee on Environment this evening.