He said findings from one survey suggested 77% of New Zealanders want water to be levied.
"I think if it becomes a reality, it's about finding a way to make the best of a bad situation - that's where the idea has come from."
Labour has said it will implement water levies if it comes into power.
If it gets the green light, the proposal will mean a royalty on the commercial consumption of water will assist with the cost of keeping "our" water clean, Labour's policy says.
Households and councils would not pay any water royalty. The royalty would be flexible to reflect the scarcity or abundance of water in different regions, the different quality of water, and its use. The royalty for bottled water would be per litre and the royalty for irrigation water would be per 1000 litres. Levels would be set following consultation and the revenue would largely be returned to regional councils.
IrrigationNZ has challenged Labour's proposal after an analysis of the latest Ministry for the Environment data on water quality showed rivers in areas with irrigation were more swimmable than those elsewhere.
IrrigationNZ chief executive Andrew Curtis said while he supported rivers being cleaned, the project should be dealt with at a regional level.
"We've already got a Canterbury regional management strategy in place. Let's carry on with that."
While a rebate was not the solution, it was a "good idea if we had to go down that road", he said.
Federated Farmers national president Katie Milne said no details had yet been revealed on how Labour's proposal would work if it went ahead.
What was clear was it would target irrigation, she said.
However, she was unsure what investigation had been done before the concept of taxation was "pulled out of the hat".
And, if it was to go ahead, the money left over for cleaning waterways would be a "pittance" by the time the likes of administration and iwi took their cut.
In the meantime, lots of work was under way to help deal with water issues.
"We're running really fast on things and want to do more," Ms Milne said.
"Everyone has got to do their bit."