Irish Water is planning to spend €5.5bn of public money over the next five years.
The funds will be used to remove lead piping from the infrastructure system and to install half a million boxes for water meters.
To cover its costs the utility has borrowed €200 million from the European Investment Bank with contracts due to be signed in the coming months.
However Irish Water's future remains uncertain as Fianna Fáil and Fine Gael - the country's two biggest political parties - having opposing views on its abolishment.
Fianna Fáil has said it wants to see water charges abolished by the next Government.