Cow numbers and dairy conversions in Canterbury– what’s the story?

Steadily declining since 2013, this year has seen just 10 new dairy conversions in Canterbury. Is this a trend and what should Cantabrians expect from Environment Canterbury in future?

As the region places increased scrutiny on the impact of farm intensification on Canterbury’s waterways, Environment Canterbury is confident that its strict water quality limits are holding the line.

This information outlines what is required of farmers, the trends over recent years and the way the rules work.

It also explains Environment Canterbury’s role and powers, and how farmers are responding to the requirements.

Is reducing cow numbers the answer?

In mid-2018, Environment Minister David Parker stated that some dairy farmers may have to reduce cow numbers in order to address the condition of the country's waterways.

In Canterbury, nitrate levels in our waterways have been rising, mostly caused by more intensive farming in the region from the 1990s. Environment Canterbury’s response to rising nitrate levels was the Land and Water Regional Plan, introduced in 2012 which included strict nitrogen loss limits and Good Management Practice guidelines now adopted by central Government.

Farms that could not control the amount of nutrients being leached from their farm into waterways were required to introduce measures to ensure leaching is at or below 2009-2013 levels, while in areas with rising nitrate levels, further reductions were also demanded.

These controls, in place to protect waterways from intensive land practices, mean that stocking levels are effectively capped for most dairy farmers in Canterbury. Still, a few farmers operating at the top end of the environmental management spectrum have converted to dairying or extended their current operations, enabled through making significant improvements that ensure they continue to meet their nitrogen loss limits. Compliance and independent auditing requirements make sure they do this.

At Environment Canterbury, we refer to this as ‘managing within limits’.

Are cow numbers and dairy conversions increasing?

Since 2012, when the Land and Water Regional Plan was introduced, nutrient leaching rules and various economic factors have had an impact and growth in dairy cattle numbers has slowed substantially, with markedly lower increases year on year.

In 2002, there were 542,610 dairy cows here in Canterbury, with substantial growth between 2002 and 2012.

Dairy cow numbers

Since then, while dairy cattle numbers have not decreased, the growth seen between 2002 and 2012 has slowed significantly. Statistics New Zealand data tell us that by 2017, Canterbury had 1,308,0581 dairy cows, an 8.9% increase since 2012, when there were 1,200,293. This data accounts for all dairy cows (including replacement stock, which aren’t in the milking herd).  According to Dairy Statistics information, there were 952,363 milking cows in Canterbury during the 2017/18 dairy season.

Statistics NZ releases 2017/18 dairy cattle figures in mid 2019.

Dairy cow annual percentage changes


The number of dairy cattle reduced substantially from 2015 to 2016, largely due to market influences, and has then increased slightly, with the latest 2017 figures showing a 2.9% increase on the previous year.

Change in dairy effluent consents granted over time 

In the last year, our data shows a small increase in dairy farming, demonstrated by the number of Dairy Effluent consents granted, which equates to 10 farms being converted from another farming land use. There were also 27 applications for an increase in dairy herd size. The numbers of conversions in the latest figures are small compared to the total of 1,333 farms with a dairy effluent consent in Canterbury.

Most of these (7 of the conversions and 22 of the herd size increases) have happened within irrigation schemes, collectives and enterprises (‘schemes’), where nutrient loads are distributed amongst farmers on an “overs or unders” basis, but cannot exceed the overall nitrogen load allocated to the scheme. The way that irrigation schemes must manage their nutrient loads makes compliance reporting highly transparent and simple to report.

For farmers outside irrigation schemes, all the conversions and herd size changes have been within allowable nitrogen loss rates, meaning that the farmer has made environmental improvements elsewhere to offset the additional nitrogen loss from the additional dairy cows.

Why the slowdown in dairy conversions over recent years?

Farms looking to convert from another land use can only do so within the farm’s existing nutrient leaching limit, which makes dairy conversions increasingly difficult to do. A farm previously used for sheep farming, for example, would need to make significant environmental enhancements to ensure that the increased nutrient load from dairying was offset.

In the Mackenzie Basin, which has been the subject of intense public scrutiny recently, there have been no new dairy conversions since the 2014/15 year, when the Simon’s Pass farm was consented. Read more about how stricter controls have had an impact on farming in the Mackenzie here.

Should cow numbers be capped?

Can Environment Canterbury simply impose a moratorium on increasing herd sizes, or on new dairying conversions?

When we were considering the Land and Water Regional Plan, this approach - of managing inputs, type of land use, or cow numbers rather than outputs – was considered. It was rejected in favour of managing outputs; those contaminants coming off the land and ending up in our waterways.

This effects-based environmental approach imposes nutrient loss limits that allow farmers to manage their activities within these limits. In other words, rather than managing intensification of farming activities by capping cow numbers or managing herd sizes, farmers have scope to introduce a range of environmental improvements. The more beneficial these improvements, the smaller the rate of nutrient loss to the surrounding waterways.

Selwyn-Te Waihora, for example, nitrogen losses from dairy farms must be reducedThe rules, introduced via the Canterbury Land and Water Regional Plan became partly operative from September 2015, and are some of the strictest in the country, supported by increasingly stringent rules in areas with rising nitrate levels.

These include Selwyn district, Ashburton Hinds, and the South Coastal Canterbury area. In Selwyn-Te Waihora, for example, nitrogen losses from dairy farms must be reduced to 30% below their average 2009-2013 nitrogen losses by 2022.

Further sub-region plan changes are in the wings for Orari Temuka Opihi Pareora and Waimakariri, while the imminent Nutrient Management and Waitaki Plan Change (PC5) requires adoption of Good Management Practices and will further manage the loss of nutrients from farming activities.

What does ‘managing within limits’ mean?

In Canterbury, farmers require Dairy Effluent consents and Land Use consents to operate a dairy farm. These consents place constraints on the farming activity dependent on the amount of pollutants discharged to land and water, as well as enforcing catchment rules to meet the needs of the local environment.

Recent years have seen a comprehensive approach by Environment Canterbury and the farming industry to address environmental concerns including:

  • stricter and more targeted planning rules and nitrogen loss limits
  • application of industry-agreed Good Management Practices and
  • introduction of audited Farm Environmental Plans

Rules included in the LWRP 

As a result, the playing field has shifted for farmers. Good Management Practices are now well entrenched, with farmers required to implement these and to meet the appropriate nutrient limits.

The Land and Water Regional Plan requires the 3400 Canterbury farmers who irrigate, farm in sensitive areas, intensively winter graze livestock or have nitrogen losses over an established baseline to have a land use consent.

Farm Environment Plans are required prior to applying for land use consent, ensuring that land owners record how they intend to manage their environmental footprint right across the property, including such things as irrigation application, fertiliser use, offal pits, and waterway fencing.

The Farm Environment Plan also includes a baseline calculation of a farm’s nitrogen losses. Future nitrogen losses must not exceed this baseline, and in some cases must reduce.

Farming efficiently, to limits, and using modern systems enhances environmental outcomes, demonstrating that looking at the bigger picture of nitrate and other pollution on farms fosters a culture of continuous improvement.

Adherence to these limits is monitored through regular Farm Environment Plan audits.

Ensuring compliance: Auditing of farms

Audits demonstrate a farm’s progress towards meeting Good Management Practices and water quality limits. Consented farms require regular audits at intervals of between six months and three years (or four years for collectives and irrigation schemes) depending on their previous grades. Non-compliant farms are audited more frequently.

A grad to D grade graph

A and B grades are compliant, while C and D grades are not. Repeated instances of a C or D grade result in enforcement action which can mean prosecution or revoking a farmer’s Land Use Consent to Farm.

We are now seeing many farmers viewing Farm Environment Plans as good business practice, implementing Good Management Practices, and passing their audits.

The most recent audit results demonstrate that 90% of those audited in 2017/18 (755 farms) have achieved an A or B audit grade. These are farms that are meeting or doing better than the nutrient limits imposed through the Land and Water Regional Plan, and their relevant sub-region planning rules.

In some cases, these farmers are then able to look towards growth, whether this be through increasing what they are already doing on their land, or converting to a new land use, such as dairy farming.

Managing within nitrogen limits
What impact are the rules having?

Environment Canterbury is driving farmers to improve management of both nutrients and water resources through the Land and Water Regional Plan. The plan was made partly operative in September 2015, and fully operative in February 2017.

The plan was made partly operative in September 2015, and fully operative in February 2017.

In Selwyn Te Waihora, Hinds, South Coastal Canterbury and Waitaki, further steps have also been identified and implemented in conjunction with zone committees and local communities. An example is in Selwyn Te Waihora/Lake Ellesmere where dairy farmers will need to make an additional 30% reduction in their nitrogen losses by 2022.

Across Canterbury, through promoting the planting and fencing of riverbanks, ecological restoration, smarter technology and better reporting of progress, we are encouraging a whole of farm approach to environmental management. We are starting to see improvements in water quality trends over the past 5 and 10 years.

Although this is only part of the picture and needs to take into account broader ecological measures, and the fact that nitrates already in the ground will take some decades to come through, it is encouraging and we are headed in the right direction.

aerial shot of a dairy farms