Irish Water made a pre-tax loss of €138.8m last year, according to annual results released by its parent company Ervia.
The utility assumed responsibility for water operations from the country's local authorities last year, bringing in revenue of almost €687.2m, largely from commercial charges.
As domestic billing was delayed until this year the results do not include any revenue from households, however.
During 2014 Irish Water had operating costs of more than €793.7m, while a further €10.3m went to cover losses on a defined benefit scheme.
During the period the company spent more than €547.8m on investments in 2014, while almost €257.6m was spent on payroll and other staff-related overheads.
Managing director John Tierney received remuneration of €248,000 during the year, while a total of €1.7m was given in salary and remuneration to senior management.
A further €126,800 was paid in directors fees to members of the board, while €6,000 was given in expenses.
In 2014 Irish Water received a capital contribution of €407m from the Government, while a further €200.2m was gained in borrowings.
While Irish Water is part or Ervia its results are reported separately for accounting reasons.
In its separate results Ervia, which also controls Gas Networks Ireland, reported a pre-tax profit of €137m in 2014 on revenues of €506m.
During the year it paid a dividend of €189m to the State, which included the initial proceeds of the sale of Bord Gáis Energy to British group Centrica.
Ervia said it had successfully rebranded Bord Gáis Networks as Gas Networks Ireland during the year, and had completed €65.5m worth of investment and maintenance programmes on time and on budget.
The group had also revised its structure, putting a board in place to oversee the operation of both Gas Networks Ireland and Irish Water.
Ervia’s chief executive Michael McNicholas was given remuneration of €334,000 in 2014 – compared to a figure of €218,000 in the previous year.
A further €106,000 was paid in fees to members of the board, while €75.76m was spent on the group’s total payroll.