Fine Gael and Labour have voted against each other for the first time in the history of the current Government.
Labour senators joined the opposition to approve calls for a referendum to make sure Irish Water cannot be sold.
Meanwhile, Enda Kenny has played down comments by Joan Burton, who said a family of four adults would pay water charges of under €200 a year.
The Taoiseach said his deputy was speaking in a personal capacity.
"The decision to be made should be one that will have a regime of charges that are simple, that are clear, and that are affordable," Mr Kenny said in the Dáil.
"The comment made by the Tánaiste yesterday is in respect of making the charges as fair and as affordable as possible - but the Government have not made a decision on this yet. "
However, the Tánaiste said she stands by her comments, saying there needs to be an expanded time period for flat charges.
"It's probably the biggest utility in this state, on a countrywide basis, … since the ESB. It is going to take us some time to [set it up]," she said.
"In that context … including the metering and the period of people getting used to the metering, I do think it needs an expanded time period … that's something that is being discussed."
Sinn Féin leader Gerry Adams responded to the Taoiseach's comments in the Dáil by saying "the game is up in relation to the fiasco of your attempt to impose a tax on water."
"Here we have the Taoiseach repudiating the Tanaiste. The question is, which one of you is tweedle dum? And who is tweedle dee? Taoiseach, is the Tanaiste not part of the Government?"
Earlier, the Minister for the Environment, Alan Kelly, said the full package would be announced next week - and that Joan Burton's comments were "reasonable assessment" that he supported.
Meanwhile Health Minister Leo Varadkar wouldn't be drawn on how much people should pay for water - but he conceded that clarity is now needed.
""There's clearly a lot of public anger about water charges," he said. "But that that same time I think the vast majority of people realise that metering water and charging for it makes sense.
We need to invest more in our water network, and that money has to come from somewhere. We haven't' been investing enough in the past," he said, but added that there were concerns over affordability, privacy, and water quality.
"It's incumbent upon us now to put together a package of measures in that space."