Ashburton Forks Catchment Group: A Year On

Over the past year, the Ashburton Forks Catchment Group has moved from establishment into delivery. The emphasis has been on practical action, learning from what’s happening on the ground, and building a group that provides value for the people farming in the catchment.

The group covers the Ashburton Forks, Staveley and Alford Forest areas, bounded roughly by the Rangitata Diversion Race, Thompsons Track, and the North and South Branches of the Ashburton River. It’s a distinctive part of Mid Canterbury, sitting close to the foothills and containing a number of regionally significant waterways. Those features have naturally shaped the priorities the group has chosen to focus on.

Two main workstreams have carried most of the effort over the past year: pest and predator control, and water quality and biodiversity monitoring.

On the pest and predator side, much of the progress has come from farmers simply getting on with the job. Across the catchment, members have been shooting, trapping and controlling pests as part of normal farm management, but with more coordination and shared focus than before.

To date, recorded control across the group includes more than 2,500 possums and over 2,700 hares, along with rabbits, magpies, rats, cats, mustelids and a range of other pest species. These numbers aren’t about targets or reporting for the sake of it. They reflect a concerted effort to protect planting investments already made by farmers and to reduce ongoing pressure on biodiversity values across the catchment.

Auto-traps have played an important role. There are currently 31 AT220 traps operating across the area, most owned by the group and some privately. They have proven effective, particularly for possums and rats, and have also captured a range of other pest species. One clear lesson so far is that pest control is far more effective when it is coordinated. Without a catchment-wide approach, reinvasion happens quickly and effort is easily lost.

Water quality monitoring has been the other major focus. Since the groups formation, farmers have collected 777 nitrate-nitrogen samples from waterways across the catchment. This has provided a robust baseline and a clearer understanding of conditions across different parts of the system, rather than relying on isolated or one-off measurements.

Independent input has been a key part of this work. Hydrologist Brett Painter has reviewed and assisted with the design and analysis of the monitoring programme, providing confidence that the data being collected is fit for purpose. That independent oversight is important, both for credibility and to ensure monitoring effort is proportionate and well targeted.

In addition, eDNA testing was completed at a number of sites across the catchment. This provided an objective snapshot of aquatic biodiversity present within local waterways and helped build a more complete picture of catchment health. The results have been useful in informing future monitoring and reinforcing the value of ongoing protection and enhancement work.

Support from the Mid Canterbury Catchment Collective (MCCC) has been critical in enabling the group to function effectively. Assistance with facilitation, training and funding has allowed the group to operate in a structured way, rather than relying entirely on volunteer time. Planned GIS mapping of the catchment will further strengthen understanding of water flows, biodiversity values and monitoring coverage.

Like most catchment groups, long-term funding remains a challenge. The group currently operates on a modest membership fee, which contributes to costs but does not fully fund facilitation or projects. Maintaining financial sustainability while retaining a farmer-led approach will remain an ongoing focus.

At its core, the Ashburton Forks Catchment Group is about building shared understanding and giving farmers good information to support their own decisions. Progress has been steady rather than flashy, but it has been practical, grounded and driven by the people farming the land.

Will WrightFacilitator, Ashburton Forks Catchment Group