Protecting and enhancing the Ahuriri and Upper Waitaki catchment

We are carrying out a focused piece of work in the Ahuriri and Upper Waitaki area to support long-term improvements in water quality, protect wetland and biodiversity values, and uphold the cultural significance of this unique area.

We need to protect the ongoing health and water quality of Lake Benmore, specifically the Ahuriri Arm where current nutrient concentrations and algal biomass (phytoplankton) are causing concern. Lake health is measured in a Trophic Level Index (TLI) score and is monitored by our science team.

View our latest water monitoring results for the Upper Waitaki area (PDF file, 5.38MB).

Action is needed to avoid further pressure on the catchment's ecological, cultural and recreational values.

Working alongside farmers and the community

We’re committed to working with the Ahuriri and Upper Waitaki community — including landowners, rūnanga and catchment groups — to support practical, long-term improvements across the catchment.

This includes:

  • working with consent holders to ensure their activities comply with the regulatory framework and contribute to the outcomes sought
  • helping farmers meet permitted activity rules, especially around protecting wetlands and waterways
  • supporting on-farm or community-led initiatives that go above minimum requirements
  • backing work that improves water quality, protects biodiversity, and enhances mahinga kai.
Map of the Ahuriri Catchment, highlighting the network of rivers and streams flowing into the Ahuriri Arm of Lake Benmore (EOS Ecology)

Map of the Ahuriri Catchment, highlighting the network of rivers and streams flowing into the Ahuriri Arm of Lake Benmore (EOS Ecology)

Significant wetlands

The Upper Waitaki has some of the most significant remaining wetlands in Waitaha Canterbury, but many are fragmented or under pressure. These wetlands help filter water, store carbon, and provide critical habitat for threatened species. We’re working to offer specialised advice to map, identify and support wetland areas so we can support farmers and landowners in ongoing protection, management and enhancement.

Progress updates

Pest willow control: We’ve worked with landowners to target more than 270 hectares of pest willows, including within the Wairepo catchment.

Catch cropping trials: The team is also supporting three catch cropping trial sites, using  special frost-hardy oats to help reduce nitrogen leaching following winter grazing.

Farm action plan visits: We’ve started working with farmers operating under permitted activity rules in the catchment to check their on-farm practices and create tailored Farm Action Plans. The purpose of these Farm Action Plans plans is to:

  • identify risks and outline practical steps to ensure regulatory requirements are met in the context of the property and catchment
  • manage and mitigate environmental impacts as part of a broader, long-term strategy to protect and restore the catchment’s unique natural assets
  • secure any grants or incentives that may be applicable to the work.

Where farmers already have a Farm Environment Plan (FEP), the Farm Action Plan builds on that.

More information about this work

Our team are happy to talk to you about this work. Get in touch with them via email:

Get in touch with your local catchment group

The Omarama Stream Water Group (OSWG) has been functioning for over a decade and its purpose is to maintain and enhance values associated with water in the Omarama Catchment.

The Ahuriri Catchment Community Group (ACCG) is a broad umbrella group. Its purpose is to “ensure that the Ahuriri Catchment remains thriving and sustainable for future generations.”

If you want to know more about either group contact Bridget on 021 072 2113.

To stay up-to-date about the our progress in the Ahuriri catchment, sign up for our newsletter.

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Retrieved: 3:43am, Wed 26 Nov 2025
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