For the first time, New Zealand's farming leaders have come together not to lobby a government or defend environmental criticism but to make a pledge for change.

The change committed to is for New Zealand's rivers being swimmable for our children and grandchildren.

It's not that we have been blind to the environmental challenges New Zealand is facing. But like climate change, some issues are too large for just one sector to manage on its own. Water quality is one of them.

While the dairy sector voluntarily launched the sustainable dairying water accord in 2013, and has made significant headway improving farming practices, this is the first time all livestock farming sectors have agreed to work together for change.


But we alone can't make all the changes needed to improve the country's water issues.

Both urban and rural communities contribute to the environmental footprint we leave behind, including contributing to poor water quality. We are all responsible for finding the varied and many solutions required to address this issue, which is why the pledge this week by our Farming Leaders Group is so significant.

No doubt some of you will see this pledge as an admission of guilt by farmers. In some ways, you aren't wrong. We know we haven't always got things right. Like many sectors over years gone by, practices that were once considered harmless and the norm are now known to be unacceptable.

Science told us that farming practices needed to change, and these changes are happening. In fact, there has been a marked change over the past decade by dairy farmers. But whatever we do from here on to improve our environmental footprint, the uninformed practices of past years have already done the damage. We are working to solve it. It's a long-term challenge, and one that needs all farming sectors involved.

I am a proud dairy farmer. I am proud of the land I look after and the animals I care for. I want my grandchildren, and one day my great-grandchildren, to be able to swim in the same rivers that I did growing up.

Our dairy farmers are on board. The vast majority want to improve their environmental footprint. That's why DairyNZ has spent more than $18.5 million on research, and a further $10.6m on environmental work last year. We want to know what drives water quality, how to improve it, and how to alleviate pressure on our waterways.

Our research has shown that fencing waterways reduces contaminant loss, including nitrogen, phosphorus, sediment, and E. coli. That's why dairy farmers have fenced 97 per cent of Water Accord waterways.

Our case studies have shown that planting 3m of grass along waterways can retain or transform nutrients, reducing nitrogen and phosphorus losses, and sediment losses by 35-87 per cent. That's why dairy farmers are making riparian action plans, leaving grass filters in place, and planting natives along riparian margins of waterways.


And that's also why the dairy sector has voluntarily committed to every dairy farmer having a riparian action plan by 2020 - to help support the regional water quality plan changes happening now and into the future.

Dairy farmers are doing this. This is science meets action to improve our waterways. This pledge is our promise to you, to all New Zealanders, on behalf of the farming sector that we are committed to playing our part to lift water quality in New Zealand.

We want our children and grandchildren to be able to swim in our nation's rivers. We are owning our part of this mission. New Zealand can hold us to this commitment.

• Michael Spaans is chairman of DairyNZ. The Farming Leaders Group, an informal grouping of pastoral farming leaders, was established in May to work on issues of importance to the sector.