Environment Canterbury responds to Overseer review

We're implementing an interim solution to respond to the Government’s review of Overseer. Find out how this may affect you.

Science Director Tim Davie said that in light of the review’s findings, it was necessary to develop an interim solution to allow consent processing and Farm Environment Plan auditing to continue with less reliance on Overseer.

“We needed to provide as much certainty as possible to farmers and the community as soon as we could. I am confident that our temporary interim solution, developed with mana whenua[¹] and stakeholders, deliver on this,” he said.

“We now have the means to keep working within our current regulatory framework, without compromising water quality, at least until a new land and water plan is notified in 2024.

Interim solution

“The interim solution means we no longer rely on Overseer to ensure that nitrogen losses from farms with a nitrogen limit are compliant with their consent conditions, not increasing – and in some cases – reducing.” 

Dr Davie said the interim solution would be: easily understood, implementable and auditable (auditors are already working with new guidance); would uphold the intent of the Canterbury Land & Water Regional Planat least holds the line on nitrogen losses from farms; gives farms some operational and seasonal flexibility within the set limits; and would minimise costs to the community, farmers and us.

“For example, we anticipate that we will be receiving more resource consent applications from farmers as a result of these changes,” Dr Davie said.

“Unless intensification is the likely result of what they are proposing, the cost to them will probably be similar to the current cost. They can also expect that if their consent is granted, it may be of relatively short duration as we head towards a new planning framework in a few years.”

“We acknowledge the challenges farmers and the wider community are facing in the freshwater space, so we are committed to working with them to ensure a smooth transition,” he said.

“The fact remains, however, that the amount of nitrogen a farm loses to water is directly linked to significant farm management activities.

“The interim solution will allow us to track and monitor these activities, with an Overseer number being one of several lines of evidence allowing us to do this.

“We would advise farmers against making changes to their consented farming systems without strong evidence that they will be able to meet their nitrogen loss limit.

“In the meantime, we welcome the Government’s commitment to continue to support Overseer while it looks into providing upgraded and/or next-generation tools over the next 12 months,” Dr Davie concluded. 

¹Consent applications and Farm Environment Plan audits have started again in most areas of Canterbury. The exceptions are in the far northern and far southern parts of the region, where discussions with the local Rūnanga have not yet concluded. We anticipate this will happen in early 2022 but contact us if you are unsure about whether applications and audits have started again in your area. Back to top.

Further information

Frequently asked questions about Overseer

What is Overseer?

The Overseer modelling tool is one of the few ways that nutrient losses from land can be estimated. Our Resource Management Act plans and consents use Overseer, alongside Farm Environment Plans (FEP) and independent audits, to maintain or improve water quality by minimising nitrate-nitrogen losses.

Overseer is used in Canterbury in several ways:

Overseer is also used by some irrigation schemes to manage their consented nitrogen load, including through FEP audits of individual farms, although schemes also use other checks and limits to manage individual nitrogen losses from farms and are less dependent on Overseer for this.

Why is an interim solution needed?

We have a number of ways of managing water quality, one of which is a modelling tool, currently Overseer.

In light of the review's findings, we needed to find a way to allow consent processing and Farm Environment Plan auditing to continue with less reliance on Overseer.

Nutrient limits have been imposed regionally and at catchment level, and we have a comprehensive Farm Environment Plan auditing regime.

As required by the Government's Essential Freshwater package, a new planning framework will be notified by 2024.

This will build on the collaborative work undertaken with the community, mana whenua and water zone committees over the last decade.

How can the community be confident that water quality won’t be compromised? 

Overseer is a modelling tool only; it’s on-farm performance that really matters. The Good Management Practice regime in Canterbury involves audited Farm Environment Plans.

We are committed to working with mana whenua, farmers and the wider community to ensure Canterbury’s water quality is maintained and enhanced. This will be possible with the interim solution.


How can auditors do their job without Overseer? What confidence can the community have in an objective assessment?

There is a range of other measures that auditors can use in their assessment including stock exclusion, riparian management, management of mahinga kai, water use efficiency and nutrient management.

They have been given comprehensive training and guidance, and the software has been amended to reflect this.

Why will there be more B grades than A? Does this mean farmer performance has dropped?

This may be the case for the first audit particularly, where the new approach to auditing seeks to establish whether the farmer’s loss limit has been met. It does not necessarily mean that the farmer’s environmental performance has diminished.

 Water quality

Measuring nitrogen loss is critical to improving water quality – how will this be done?

We will do this through our auditing programme, which considers a very wide range of on-farm objectives and actions. If in future an enhanced modelling tool becomes available, we may be able to introduce this into the measurement mix.

Will nitrogen reductions required, for example in Selwyn Te Waihora by 2022, be achieved? How will you measure whether they have been?

We are confident that these reductions will be achieved by most farmers. Some existing consents require a reduction in nitrogen loss rate rather than “holding the line” at the nitrogen limit. For example, Selwyn Te Waihora consents greater than 15 kg N/ha/yr require reductions from 1 January 2022.

In the Waitaki catchment, some consents are tied to the monitoring of lakes and rivers, and reductions are required if certain water quality limits are breached. A working group is looking into these consents.

How will you manage high-risk land use change? What does high-risk mean?

Potentially high-risk activities include those involving irrigation and intensive winter grazing of stock.

We work closely with irrigation schemes to ensure compliance with consented nutrient loads.

Intensive winter grazing is always a compliance priority for us.

The range of inquiries we make when we receive a new resource consent application and the broad scope of our auditing regime mean that high-risk land-use change is well managed and monitored.

Irrigation schemes 

What are the changes for irrigation schemes? Will their consents continue to be rolled over?

Irrigation schemes use Overseer in different ways. We are working with them to ensure that the interim solution is implemented appropriately for them and their shareholders.

We are obliged to consider new consent applications under our statutory direction, but in the interests of certainty with a new plan to be notified by 2024, short-duration consents are likely.