For Andrew Booth, the issue of water quality is very close to home. He wants his daughters – Tamsyn, 5, and Hannah, 3 – to grow up swimming in the river where he and his family swam when they were kids.
Andrew and wife Vicky are sharemilkers on a 174ha, 430-cow farm in Titoki, 30km west of Whangarei alongside the Mangakahia River. They also have a 30 per cent share in a nearby farm with his sister and parents.
His grandfather and father worked this land and Andrew has lived there all his life, apart from stints studying at Lincoln University and on farms in Canterbury, Hawke's Bay and Waikato.
"Growing up on the land has certainly made me appreciate it a lot more. As kids we were always down there swimming in the river throughout the summer," Andrew says. "We're quite lucky – we've got a nice little beach down in one of the bends on the river. We always went down there as kids and used to make mudpies – they probably aren't the best thing for sediment in the water but that's what you did back then.
"It's a great spot to go to in the summer because the river's nice and warm and it's a good shallow area, so we're able to take our friends and their kids down there. They spend hours in the river.
"It'd be a shame for kids not to have the opportunity that we've always had and there's no sane reason why you shouldn't still be able to swim in the rivers. The way our river is, there is no reason for it to get to the state where it's unswimmable."
Andrew is a dairy environment leader for DairyNZ and the climate change ambassador in the sector's programme to help farmers understand those issues.
He believes his family history has helped him develop a connection with the river and with water, and what it means to the farm.
When the farm was cleared, a large natural swamp was left untouched; it catches nearly half the runoff water. "I've got another area on the other side of the farm which I'm going to re-create as another natural wetland.
"It used to be a swamp that got drained. I'm going to dam it up and landscape it and make an effective wetland to filter the rest of the water that leaves our farm.
"So essentially 95 per cent of the water that passes through our farm is going to travel through a wetland or a swamp before it reaches the river. There is no sediment, no nutrients or e-coli getting into the river, which will be really nice."
Doing is one thing; letting the community know about farming and its contribution to the country is also high on Andrew's priorities. He's hosted many school parties on the property in recent years.
"Although New Zealand is such a rural-based country, there are kids who don't get the opportunity to come out on a farm. I really enjoy getting the kids out here and showing them what happens on a farm – they can pat the cows, they can see a cow getting milked.
"I get them to help me with tree-planting along the riverbank or other spots on the farm.
They start to buy into what you're doing and understand what you're doing, and they can see what you're trying to achieve. You can see on their faces that they really enjoy it and they are getting a lot of value out of it.
"They're good little voices. They can go and say: we did this and this on a dairy farm and saw these cool things going on.
"I've got nothing to hide on the farm, so I'm happy to bring people here and show them what's going on and for them to ask me why I do things the way I do them. It helps build an understanding of what we do, and how we can carry on sustainably."
He believes in using social media to spread a message to the wider community. During the 2017 election campaign, he made a video showcasing planting, effluent management and water work on his farm as a counter to claims of "dirty dairying". It reaped a positive reaction on social media platforms.
"I was motivated because I think farmers have to speak up for ourselves a bit more. Social media seems to be a platform that works quite well – you can get a wide reach to a wide range of people and tell your message in an unfiltered way.
"You can show people how it is, and that gives them ammunition to stand up for us if they hear someone saying something that is not quite correct. It's a good way to get the message out beyond my local community that dairy farmers do care about the environment."