Labour to Tax Water

[blackcap]

for a start it should be water that hits the ground from the irrigator - because that is the stuff that will eventually flow into poluted river.

It cant include the water that leaves the pivot sprinkler as some will be lost to evapouration before hitting the ground.

And even then... how do you measure that? Will it be farmers volunteering this information or will irrigators have meters on them? Who will collect this metered data?