Overseer review by independent panel concludes it could not be confident in Overseer’s ability to estimate nitrogen loss from farms. Aug 2021
Major tool for managing farm pollution gets a fail from reviewers - Eloise Gibson and Jono Galuszka (Stuff 11.08.21) https://www.stuff.co.nz/environment/climate-news/125907504/major-tool-for-managing-farm-pollution-gets-a-fail-from-reviewers (for full article)
For Government response see link here: https://environment.govt.nz/assets/publications/government-response-to-the-findings-of-the-overseer-peer-review-report-final-.pdf
An independent panel in charge of a long-awaited review into Overseer, one of the country’s main farm pollution management tools, concluded it could not be confident in Overseer’s ability to estimate nitrogen loss from farms.
The scientific panel cited “overarching structural problems” with the tool, which has been used to help manage water quality in some of New Zealand’s most troubled catchments.
Environment Minister David Parker said on Wednesday the Government would help develop other tools to more accurately measure pollution running off paddocks, as well as supporting a “next generation” version of Overseer
It was important for farmers, councils and “brand New Zealand” to have a more accurate way to measure nutrient losses, said Parker and Agriculture Minister Damien O’Connor in a joint statement.
Overseer has emerged as a management solution for two of the country’s most pressing jobs: cleaning up freshwater and reducing climate-heating gases.
But a 2018 review by Parliamentary Commissioner for the Environment Simon Upton found the tool was seriously flawed, opaque and open to gaming by farmers. Upton recommended the Government urgently review the software, which has been relied upon for years by several regional councils to determine whether farms are breaking water pollution limits.
The panel’s review only covers the use of the tool to manage run-off, not greenhouse gases.
The review found Overseer was user-friendly but not designed to accurately estimate nutrient loss – despite this being something councils use it for.
Overseer relied on the environment being consistent and did not take into account soil dynamics or sudden events like storms or dry spells, it found.
“We do not have confidence that Overseer’s modelled outputs tell us whether changes in farm management reduce or increase the losses of nutrients, or what the magnitude or error of these losses might be,” the report said. Overseer could only provide a “coarse understanding” of nutrient loss, it concluded.
But Overseer's chief executive, Caroline Read, said Overseer was being judged for something it had never claimed to do. (Abridged)