Risk index tool for on-farm nutrient management

A nitrogen contaminant discharge risk index tool (RIT) for on-farm nutrient management is part of the Government response to the findings of the Overseer peer review report.

This web-based decision-support tool will provide a practical way for land managers to meet freshwater outcomes by identifying areas of greater nitrogen-loss risk from land. It will provide a practical way for land managers to meet freshwater outcomes by identifying areas of greater nitrogen-loss risk from land. The RIT could help inform certified Freshwater farm plans (FWFPs) or Council resource consent processing as a part of a multi-evidence approach.

Nutrient management tool work programme update Dec 2023 [PDF 4.8MB]

Use of the RIT is not required under legislation. Councils may choose to use the RIT as a decision-support tool, as part of a multi-evidence approach, in their regulatory processes and/or freshwater farm plan requirements. Councils will need to develop their own specific scenarios to determine what the risk scores mean in their catchment contexts.

The RIT has gone through an independent peer-review process. Councils and Māori were consulted during the development of the RIT.

Phase one of the RIT will provide:

• a risk score for nitrogen (N) loss from farms and plantation forestry, based on environment characteristics, management practices and mitigations.
• a risk score at farm and block scale
• a heatmap that shows hotspot areas of nitrogen (N) loss risk.

NB: The RIT will not provide a kg of N number.

This enables land managers to determine how land and practice management decisions impact nitrogen-loss risk. Areas of higher nitrogen-loss risk may require greater focus to improve freshwater outcomes.

View the slidedeck for an overview of how the RIT works.

A RIT prototype was delivered for review within the Ministry at the end of November 2022. It was determined that rework was required to enable its wider use. When completed, the RIT will be available in 2025.

Phase one for the RIT will deliver an operator portal for users to complete nitrogen-loss risk assessments.

The Ministry will be seeking feedback from Councils, land managers and other users to inform the roadmap and future phase iterations of the tool.

A Technical Working Group of scientists and modellers provided technical and scientific oversight, guidance, advice, and leadership in the development of the Risk Index Tool. The Group consists of:

• Professor Richard McDowell – Lincoln University
• Dr Valerie Snow – AgResearch Ltd
• Dr Bethanna Jackson (late) – BEEA Ltd; Victoria University of Wellington
• Reina Tamepo – Scion Ltd

The Group developed technical documentation on the design and function of the RIT. These documents have undergone an independent peer-review and will be available upon release of the RIT.

Science and modelling experts from the Ministry for the Environment and the Ministry for Primary Industries have supported the group throughout the process.

Read the contaminant loss risk index tool technical document.

A nominated group of regional councils were involved in the RIT development.  This group consisted of representatives from:

• Environment Canterbury
• Greater Wellington Regional Council
• Hawke’s Bay Regional Council
• Southland Regional Council
• Waikato Regional Council

The Reference Group ensured that the RIT was developed in a manner that met various council needs. A subset of this group was involved in the RIT’s User Acceptance Testing.

Two documents are being developed and will be made available with the release of the RIT. 

RIT Implementation Guidance

To help councils understand the RIT’s potential use as a regulatory decision support tool and provide guidance on its implementation.

• NB: Although this guide is primarily written for councils, it can be used by others to understand the RIT’s role in environmental planning decisions.

Read the draft implementation guide.

RIT User Guide

To guide the user through data entry, running nitrogen-loss risk score assessments and creating reports.

To ensure you receive all future news and updates on the RIT, please email: riskindextool@mfe.govt.nz