A project to secure the water supply for the Greater Dublin Area into the future could hit €10 billion.
That's a worst-case scenario for a proposed pipeline from the River Shannon to the capital.
It will run for 170 kilometres, bringing treated water from Parteen Basin in Tipperary, to Peaumont in southwest Dublin.
The high figure follows a risk analysis according to correspondence between the Department of Housing and the Public Accounts Committee.
The Irish Times reports the bill for the proposed project has been estimated at between €3.3 billion, all the way up to €10.4 billion.
A public consultation on the scheme, that will have capacity to support water supply needs for up to half of the population, is currently underway.
