I'm no activist. I'm a farmer, and as a farmer I'm against the Adani coal mine for one reason: water.

My sugar cane farm is on the flood plains of northern NSW. Many of my friends and colleagues are in the industry located all over Queensland.

All farmers, no matter what the crop, or livestock, rely on water. Sugar cane requires about 1300 millimetres of well-spread rain to grow a crop. You might manage, with good irrigation, on 600-700mm. Too much in the form of a flood and you might end up with a damaged crop.

In a good year, everything you need falls from the sky, at the right time, in the right amount. Of course, not every year is a good year. In fact, good years are rare and that's why farmers manage risk with irrigation.

You store the water for use later with dams and the like, you try to use it efficiently and sometimes you need to extract it from underground, or truck it in.

It's all pretty basic stuff, so it's truly bowled me over to learn the detail of the Adani mine in relation to water.

Two sets of rules

Many farmers in Queensland have licences to draw their water from the Great Artesian Basin. The same basin that the Carmichael mine, once in operation, also plans to draw massive amounts of water from.

How much you ask? Good question. As much as the owners please, because the Queensland Government has granted this company unlimited access to extract groundwater.

I'd heard of Adani on the news, and of the activism against it. As a member of Farmers for Climate Action I figured it was something I should look into. What I learnt stunned me.

Right now, close friends of mine in farming in Queensland are doing it tough because of the cost of water. For every tonne of sugar cane they grow they tell me they are paying about $10 for electricity and the water allocation. That's pushing a lot of growers back into a loss-making situation. That's regardless of whether it rains, or not, and when it rains — because you pay for the licence even if you don't end up needing the water.

At the same time, we're saying to a major international company that it can have as much as it likes. Sounds like two sets of rules to me.

A scarce resource

Anyone who tries to tell you that there is plenty of water for everyone is selling you down the river. Australia is the driest habitable continent on earth. We get rain; and in some places, including mine, much more than others.

On the whole, though, Australia is dry and as I understand the effects of climate change, we are going to get less in total, but with more extreme wet events more often.

Sorry, this video has expired Drone vision of the proposed location for Adani's Carmichael mine

When you are dealing with a finite resource it's simple maths: whatever the mine takes from groundwater supplies is going to hurt farmers and the environment. That's what upsets me about the Adani mine.

It's also what upset farmers in Queensland's Darling Downs where an existing mine (New Acland) proposed a big expansion. They were worried about their air, their land and farms, their family's health, and their water.

More than 60 property owners fought against that expansion, tooth and nail, since 2012. After a record number of days in the land court they finally won their victory when their objections were upheld. The main reason? The risks to the groundwater "were too great".

Listen to farmers

My mother was fond of the saying "charity begins at home". But here we are, yet again, paying no heed to the farmers at our doorstep. Instead, we're stepping over them to give a free handshake to a big coal company from another country.

In fact, it seems there's no limit to our charity when it comes to Adani. With government after government bending over backward with promises of $1 billion loans, and delays in paying tax bills... imagine what farming businesses could do with that sort of support? All the profits would stay in our own country, too.

Those in favour of the mine are right about one thing — it is a really good deal. It's just not a good deal for the Australian people.

To me, anyone who is opposed to Adani isn't an activist. They're just using common sense.

Robert Quirk has been growing sugar cane in north-eastern NSW for more than 50 years. He serves on the Board of Australian Cane Farmers and is a member of Farmers for Climate Action.