By Gordon Rennie

Today, as I write this, is a public holiday in New Zealand as it marks the signing of a Treaty at Waitangi on February 6, 1840.

The Maori chiefs, by signing this treaty, agreed to pass sovereignty of New Zealand to Queen Victoria in return for protection and rights as British subjects as well as being guaranteed possession of whatever lands they were currently holding. So the NZ Prime Minister met with Maori chiefs at the Treaty Ground, which is highly symbolic given recent PMs have refused to attend.

If you think the Brexit talks are going to be tough, they are a walk in the park compared to the Treaty of Waitangi talks. Still ongoing after 178 years!

What is concerning NZ farmers the most is, 'who owns New Zealand’s water?' Since 1840 and long before that, water has always been free. Water is a fundamental for human live and it is a brave politician who proposes that water should be taxed.

So, constitutional lawyers are having a field day re-examining the 1840 Treaty to establish if the Treaty also gave Maori rights to the water on their lands.

Pretty much the whole of NZ arable farming, dairy farming, horticulture and wine production is reliant on some kind of irrigation. This has come into sharp focus with a prolonged heatwave that experts at Otago University have attributed to global warming, with January, 2018, being the warmest month ever recorded here.

This prolonged heatwave has seen coastal sea temperatures up from the normal 16.5-18.5°C, with water in the Marlborough Sounds exceeding 20°C. This is home to salmon farms and there are grave concerns that salmon cannot survive in these warmer waters.

This is a tipping point in this part of the world where the global warming is now a reality and hitting business where it hurts, in the pocket.

Irrigation is vital to the productivity of a dairy farm in the Canterbury/Otago regions of the South Island. Vast new private schemes have been developed in recent years with reservoirs of 500 acres.

To join the scheme and gain access to limitless water, a farmer must agree to an annual membership fee of almost £120 per acre. On top of that, to install pivot irrigation costs about £800 per acre.

Sheep and most cropping farmers can not justify such high costs, so the land almost always ends up being converted to dairying.

Until now, there has been no regulations on nitrates in water and the recent general election saw some bitter debates between the ruling National (conservative) Party and Labour. Labour stood on a platform to clean up New Zealand’s rivers and creeks and impose stringent new controls to prevent nitrates and faecal matter polluting its rivers – and it is now not safe to swim in most rivers here.

Run-off from dairy farms into rivers exacerbated by non-stop irrigation has been identified as one of the main problems.

So, some form of tax or levy on water use has been mooted by the new minority Labour government who rely on the Green Party to stay in power. As I was driving up from Timaru to Christchurch Airport this week, I listened to a debate on Radio NZ National. The debate was a speculation as to what of any concessions the new PM, Jucinda Ardern, may concede today on water rights.

There is also some concern amongst Maoris that commercial companies are selling bottled NZ water overseas without any real debate as to who owns the water in the first place?

The experts in this part of the world have warned that warmer summers and rising coastal sea temperatures are going to become more common. The recent heatwave has been unprecedented and even the normally more temperate Invercargill has seen the thermometer reach 39°C.

For combinable crops, this has resulted in yields that are 'bloody awful'. Crops simply died in the extreme heat. It is also not good news to the vast number of dairy cows that live outside all the year round, with little or no shade.

A sign of the times is that there are more than 160 dairy farms for sale in Canterbury and Otago, mainly due to rising interest rates and an inability to service debt. Four years ago, such fully equipped farms would sell for £16,000 per acre – today they are struggling to sell for £9000 per acre.

The Institution of Mechanical Engineers (EMI) has estimated that it takes between 500 and 4000 litres of water to produce 1kg of wheat, 1020 litres to produce 1-litre of milk and 15,415 litres to produce 1kg of beef.

So, water rights and who owns the water, is going to an on going debate not just confined to New Zealand. It might not be a problem in Scotland, but water is a major contentious issue across the world – sometimes we are lucky to have it!