Irish Water is not a popular body with the Irish public these days. So when a Government politician talks about the topic, they tread lightly.

On a day when his ministerial colleagues were criticising the management of Irish Water, Fine Gael Senator Martin Conway appeared on the Vincent Browne show to debate the issue - and, in an attempt to say water needs to be paid for, told the nation that water "doesn't fall from the sky".

"Water is a finite resource … water needs to be paid for, it costs - it doesn't just fall out of the sky," he said, quickly adding: "it has to be purified."

He's technically right that water is a finite resource. Estimates go to about 1,260,000,000,000,000,000,000 litres (that's 1.26 septillion) of water on earth, but only a tiny fraction of that is fresh water.

And, given the water cycle we all learned of in school, there's only a limited amount of that which will fall as rain, so he's technically correct on that count.

But, in Ireland at least, it definitely falls from the sky with alarming regularity.

Still, in selecting an idiom for national TV, he could have chosen "doesn't grow on trees", which likely wouldn't have provoked the same response.

Dear @FineGael @IrishWater according to Sen Martin Conway "water doesn't just fall from the sky" Where does it come from? Regards Confused. — MrsMcG (@LollyMoonshine) October 21, 2014