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12 December 2018

Media release – Transparent Overseer needed to regulate water quality

A report on whether Overseer is suitable for use in regulation to help clean up Aotearoa New Zealand’s rivers and lakes has been released today by the Parliamentary Commissioner for the Environment, Simon Upton.

“It is time to open up Overseer. If the Government wants to see the model being used as a regulatory tool then a large measure of transparency is needed, said Simon Upton today.

Overseer was originally developed as a farm management tool to calculate nutrient loss but is increasingly being used by councils in regulation. Excessive nutrient run-off from farms has an impact on the health of waterways.

“To ensure cleaner water, farmers and regional councils need to be confident that Overseer’s outputs are reliable, said Mr Upton.

“To help build confidence there needs to be more transparency around how the model operates.  Any model operates with a measure of uncertainty. That’s normal. The question is whether the level of uncertainty is an acceptable one.

“Confidence in Overseer can only be improved by opening up its workings to greater scrutiny.

“It will take time to improve Overseer and provide transparency around how it operates. In the meantime, regional councils can continue to use it but they need to be aware of its limitations.”

The Overseer and regulatory oversight report finds that important elements of the model are not open for review, and some gaps and shortcomings need to be addressed.

The report recommends that if the Government wants to see Overseer used as a regulatory tool, then it needs to address a number of issues. These include:

  • commissioning a comprehensive evaluation to ensure the Overseer model is independently peer reviewed, and is subject to sensitivity and uncertainty analysis
  • providing greater transparency around how the model works
  • aligning Overseer’s ownership, governance and funding arrangements with the transparency required for it to be used as a regulatory tool
  • providing official guidance on how Overseer should be used by regional councils.

Read the Commissioner’s report, Overseer and regulatory oversight – Models, uncertainty and cleaning up our waterways.




For more information please contact Carl Walrond on 022 032 3480

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