Restoring the Kahahakuri Catchment: Farmers Unite to Tackle Cow Cress and Erosion

In the heart of Hawke’s Bay, within the Kahahakuri catchment, a group of forward-thinking farmers is coming together with one clear purpose: to protect and restore the health of their waterways.

With support from Tukituki Land Care and in collaboration with the Hawke’s Bay Catchment Collective, these landowners are tackling two persistent challenges — the spread of cow cress and the erosion of vulnerable stream banks. This trial project is a grassroots example of how communities can lead the way in environmental restoration.

What’s the Issue with Cow Cress?

Cow cress might look similar to watercress at first glance, but its impacts tell a different story. With its larger, coarser leaves and bitter taste, it’s an invasive plant that has taken hold in many farm drains and stream margins.

Over the last eight years, cow cress has spread significantly — a problem likely worsened by milder winters and regulatory changes surrounding stock exclusion from waterways. Its dense growth not only chokes streambanks but also raises the risk of flooding and blocks drainage infrastructure.

A Collaborative Solution on the Ground

Determined to act, farmers from the Kahahakuri catchment secured a grant through Tukituki Land Care to launch a trial focused on practical, nature-based solutions. Partnering with Advance Landscape Systems, they’ve deployed an innovative method using FuturFiber Hemp Weed Matting — a biodegradable weed suppressant — paired with strategic planting of native carex secta.

The trial spans three unique sites, each selected for its distinct conditions. The project is also supported by Mauri Oho, a mana whenua-led initiative driving native biodiversity restoration in the region. They’re working closely with NZ Landcare Trust, local farmers, and other partners to deliver results that reflect both ecological and cultural values.

Spotlight: An Organic Dairy Farm Leads the Way

At one of the trial sites — an organic dairy farm — a no-spray approach is being tested. Eco-sourced plants from Central Natives are being planted through the hemp matting, which is secured with biodegradable pegs along the stream edge. The goal: establish a thriving native canopy within 24 months to suppress weeds naturally and stabilise the banks.

What’s Next?

These sites will be closely monitored over the coming seasons by farmers and catchment advisors. Growth rates, weed suppression, erosion control, and plant survival will all be tracked to assess performance and inform future planting efforts.

This project is more than just a weed control trial — it’s a showcase of community-led restoration in action. By combining local knowledge, sustainable materials, and native planting, the Kahahakuri catchment is laying the groundwork for long-term ecological health.