The folks at Quilter Cheviot are flushed with excitement because they think the taps are about to open on water as an investment (apologies for the puns).

The reason they think this is because climate change and demographic shifts mean companies will need to do "more with less".

Caroline Langley, deputy fund manager of the Quilter Cheviot Climate Assets fund range, said: "Water is becoming increasingly scarce and as a result we need to be more efficient with it.

"There are significant growth drivers for the industry, with population growth driving demand, urbanisation altering where reliable pure supplies are most needed, and climate change exacerbating the supply demand imbalance."

She also pointed to electrification and the rise of artificial intelligence, both of which are increasing demand for semiconductors, of which water is a key component of the manufacturing process.

Do ESG portfolio managers agree with her? Or do they think this is all just a damp squib?

The answer, if looking at the thematic fund choices is any guide, is that they actually agree to a certain extent.

Of the 20 thematic funds held in our ESG database, 20 per cent of these are water funds - including the joint most popular one.

Regnan Sustainable Water & Waste is held by three ESG allocators, along with Robeco Smart Materials and Schroder Global Energy Transition.

Robeco Sustainable Water is held by two DFMs while Natixis Thematics Water, Allianz Global Water and Lyxor MSCI Water ESG Filtered are all held by one.

Whether the tide will continue to rise on these funds, only time will tell.